Try to handle non-transient attatchment supporting GPUs

2025-05-09 13:22:19 -04:00
572 changed files with 22383 additions and 35086 deletions
@@ -57,7 +57,7 @@ SpaceBeforeInheritanceColon: true
 SpaceBeforeParens: ControlStatements
 SpaceBeforeRangeBasedForLoopColon: false
 SpaceInEmptyParentheses: false
-SpacesBeforeTrailingComments: 1
+SpacesBeforeTrailingComments: 0
 SpacesInAngles: false
 SpacesInCStyleCastParentheses: false
 SpacesInContainerLiterals: false
@@ -1,45 +0,0 @@
-name: 'Get commit message'
-outputs:
-  msg:
-    value: ${{ steps.action_output.outputs.msg }}
-runs:
-  using: "composite"
-  steps:
-    - name: Find commit message (on push)
-      if: github.event_name == 'push'
-      shell: bash
-      run: |
-        AUTHOR_NAME="${{ github.event.head_commit.author.name }}"
-        AUTHOR_EMAIL="${{ github.event.head_commit.author.email }}"
-        TSTAMP="${{ github.event.head_commit.timestamp }}"
-        echo "commit ${{ github.event.head_commit.id }}" >> /tmp/commit_msg.txt
-        echo "Author: ${AUTHOR_NAME}<${AUTHOR_EMAIL}>" >> /tmp/commit_msg.txt
-        echo "Date: ${TSTAMP}" >> /tmp/commit_msg.txt
-        echo "" >> /tmp/commit_msg.txt
-        echo "${{ github.event.head_commit.message }}" >> /tmp/commit_msg.txt
-    - name: Find commit message (PR)
-      shell: bash
-      id: checkout_code
-      if: github.event_name == 'pull_request'
-      run: |
-        echo "+++++ head commit message +++++"
-        echo "$(git log -1 --no-merges)"
-        echo "+++++++++++++++++++++++++++++++"
-        echo "hash=$(git rev-parse HEAD)" >> "$GITHUB_OUTPUT"
-        git checkout ${{ github.event.pull_request.head.sha }}
-        echo "$(git log -1 --no-merges)" >> /tmp/commit_msg.txt
-    - shell: bash
-      id: action_output
-      run: |
-        DELIMITER="EOF_FILE_CONTENT_$(date +%s)" # Using timestamp to make it more unique
-        echo "msg<<$DELIMITER" >> "$GITHUB_OUTPUT"
-        cat /tmp/commit_msg.txt >> "$GITHUB_OUTPUT"
-        echo "$DELIMITER" >> "$GITHUB_OUTPUT"
-        echo "----- got commit message ---"
-        cat /tmp/commit_msg.txt
-        echo "----------------------------"
-    - name: Cleanup Find commit message (PR)
-      shell: bash
-      if: github.event_name == 'pull_request'
-      run: |
-        git checkout ${{ steps.checkout_code.outputs.hash }}
@@ -26,4 +26,4 @@ jobs:
          path: out/filament-release-darwin.tgz
      - name: Check public headers
        run: |
-          test/check-headers/test.sh out/release/filament/include
+          build/common/check-headers.sh out/release/filament/include
@@ -1,35 +0,0 @@
-name: 'Post-submit tasks'
-
-on:
-  push:
-    branches:
-      - main
-
-jobs:
-  update-renderdiff-goldens:
-    name: update-renderdiff-goldens
-    runs-on: 'ubuntu-24.04-4core'
-    steps:
-      - uses: actions/checkout@v4.1.6
-        with:
-          fetch-depth: 0
-      - uses: ./.github/actions/linux-prereq
-      - id: get_commit_msg
-        uses: ./.github/actions/get-commit-msg
-      - name: Prerequisites
-        run: pip install tifffile numpy
-      - name: Run update script
-        env:
-          GH_TOKEN: ${{ secrets.FILAMENTBOT_TOKEN }}
-        run: |
-          GOLDEN_BRANCH=$(echo "${{ steps.get_commit_msg.outputs.msg }}" | python3 test/renderdiff/src/commit_msg.py)
-          COMMIT_HASH=$(echo "${{ steps.get_commit_msg.outputs.msg }}" | head -n 1 | tr -d 'commit ')
-          if [[ "${GOLDEN_BRANCH}" != "main" ]]; then
-              git config --global user.email "filament.bot@gmail.com"
-              git config --global user.name "Filament Bot"
-              git config --global credential.helper cache
-              echo "branch==${GOLDEN_BRANCH}"
-              echo "hash==${COMMIT_HASH}"
-              python3 test/renderdiff/src/update_golden.py --branch=${GOLDEN_BRANCH} \
-                  --merge-to-main --filament-tag=${COMMIT_HASH} --golden-repo-token=${GH_TOKEN}
-          fi
@@ -3,10 +3,10 @@ name: Presubmit
 on:
  push:
    branches:
-      - main
+    - main
  pull_request:
    branches:
-      - main
+    - main

 jobs:
  build-desktop-mac:
@@ -41,7 +41,8 @@ jobs:

  build-windows:
    name: build-windows
-    runs-on: windows-2022-32core
+    runs-on: win-2019-16core
+
    steps:
      - uses: actions/checkout@v4.1.6
        with:
@@ -54,6 +55,7 @@ jobs:
  build-android:
    name: build-android
    runs-on: 'ubuntu-24.04-16core'
+
    steps:
      - uses: actions/checkout@v4.1.6
        with:
@@ -72,6 +74,7 @@ jobs:
  build-ios:
    name: build-iOS
    runs-on: macos-14-xlarge
+
    steps:
      - uses: actions/checkout@v4.1.6
        with:
@@ -87,6 +90,7 @@ jobs:
  build-web:
    name: build-web
    runs-on: 'ubuntu-24.04-16core'
+
    steps:
      - uses: actions/checkout@v4.1.6
        with:
@@ -104,12 +108,11 @@ jobs:
      - uses: actions/checkout@v4.1.6
        with:
          fetch-depth: 0
-      - id: get_commit_msg
-        uses: ./.github/actions/get-commit-msg
      - name: Check for manual edits to /docs
        run: |
-          COMMIT_ID=$(echo "${{ steps.get_commit_msg.outputs.msg }}" | head -n 1 | sed "s/commit //g")
-          bash docs_src/build/presubmit_check.sh ${COMMIT_ID}
+           echo "${{ github.event.pull_request.head.sha }} -- ${{ github.event.pull_request.head.sha }}"
+           # disable for now
+           # bash docs_src/build/presubmit_check.sh ${{ github.event.pull_request.head.sha }}

  test-renderdiff:
    name: test-renderdiff
@@ -118,25 +121,24 @@ jobs:
      - uses: actions/checkout@v4.1.6
        with:
          fetch-depth: 0
-      - id: get_commit_msg
-        uses: ./.github/actions/get-commit-msg
      - uses: ./.github/actions/mac-prereq
      - name: Cache Mesa and deps
+        id: mesa-cache
        uses: actions/cache@v4
        with:
          path: mesa
          key: ${{ runner.os }}-mesa-deps-2-${{ vars.MESA_VERSION }}
      - name: Prerequisites
+        id: prereqs
        run: |
-          bash build/common/get-mesa.sh
+          bash test/utils/get_mesa.sh
          pip install tifffile numpy
      - name: Run Test
-        run: |
-          echo "${{ steps.get_commit_msg.outputs.msg }}" | bash test/renderdiff/test.sh
+        run: bash test/renderdiff/test.sh
      - uses: actions/upload-artifact@v4
        with:
          name: presubmit-renderdiff-result
-          path: ./out/renderdiff
+          path: ./out/renderdiff_tests

  validate-wgsl-webgpu:
    name: validate-wgsl-webgpu
@@ -151,8 +153,8 @@ jobs:
      - name: Run test
        run: ./out/cmake-debug/libs/filamat/test_filamat --gtest_filter=MaterialCompiler.Wgsl*

-  test-code-correctness:
-    name: test-code-correctness
+  code-correctness:
+    name: code-correctness
    runs-on: 'macos-14-xlarge'
    steps:
      - uses: actions/checkout@v4.1.6
@@ -163,9 +163,6 @@ jobs:
          mv out/filamat-android-release.aar out/filamat-${TAG}-android.aar
          mv out/gltfio-android-release.aar out/gltfio-${TAG}-android.aar
          mv out/filament-utils-android-release.aar out/filament-utils-${TAG}-android.aar
-          cd out/android-release/filament
-          tar -czf ../../filament-${TAG}-android-native.tgz .
-          cd ../../..
      - name: Sign sample-gltf-viewer
        run: |
          echo "${APK_KEYSTORE_BASE64}" > filament.jks.base64
@@ -187,7 +184,7 @@ jobs:
          script: |
            const upload = require('./build/common/upload-release-assets');
            const { TAG } = process.env;
-            const globber = await glob.create(['out/*.aar', 'out/*.apk', 'out/*.tgz'].join('\n'));
+            const globber = await glob.create(['out/*.aar', 'out/*.apk'].join('\n'));
            await upload({ github, context }, await globber.glob(), TAG);

  build-ios:
@@ -226,7 +223,7 @@ jobs:

  build-windows:
    name: build-windows
-    runs-on: windows-2022-32core
+    runs-on: windows-2019-32core
    if: github.event_name == 'release' || github.event.inputs.platform == 'windows'

    steps:
@@ -10,7 +10,7 @@ on:
 jobs:
  build-windows:
    name: build-windows
-    runs-on: windows-2022-32core
+    runs-on: windows-2019-32core

    steps:
      - uses: actions/checkout@v4.1.6
@@ -97,10 +97,6 @@ Make sure you've installed the following dependencies:
 - `libxcomposite-dev` (`libXcomposite-devel` on Fedora)
 - `libxxf86vm-dev` (`libXxf86vm-devel` on Fedora)

-```shell
-sudo apt install clang-14 libglu1-mesa-dev libc++-14-dev libc++abi-14-dev ninja-build libxi-dev libxcomposite-dev libxxf86vm-dev -y
-```
-
 After dependencies have been installed, we highly recommend using the [easy build](#easy-build)
 script.

@@ -49,12 +49,6 @@ option(FILAMENT_SUPPORTS_OSMESA "Enable OSMesa (headless GL context) for Filamen

 option(FILAMENT_ENABLE_FGVIEWER "Enable the frame graph viewer" OFF)

-option(FILAMENT_USE_ABSEIL_LOGGING "Use Abseil to log, may increase binary size" OFF)
-
-# This is to disable GTAO for the short-term while we investigate a way to better manage size increases.
-# On the regular filament build (where size is of less concern), we enable GTAO by default.
-option(FILAMENT_DISABLE_GTAO "Disable GTAO" OFF)
-
 set(FILAMENT_NDK_VERSION "" CACHE STRING
    "Android NDK version or version prefix to be used when building for Android."
 )
@@ -593,10 +587,6 @@ if (CMAKE_BUILD_TYPE STREQUAL "Debug" AND NOT FILAMENT_BACKEND_DEBUG_FLAG STREQU
    unset(FILAMENT_BACKEND_DEBUG_FLAG)
 endif()

-if (FILAMENT_USE_ABSEIL_LOGGING)
-    add_definitions(-DFILAMENT_USE_ABSEIL_LOGGING)
-endif()
-
 # ==================================================================================================
 # Material compilation flags
 # ==================================================================================================
@@ -1,7 +1,7 @@
 # Filament Release Notes log

 **If you are merging a PR into main**: please add the release note below, under the *Release notes
-We are chaning the way Vulkan buffers are handled. We need to switch over to a managed (or view-based) model where the data stored inside the object is a proxy to a Vulkan object that can dynamically be swapped around.
+for next branch cut* header.

 **If you are cherry-picking a commit into an rc/ branch**: add the release note under the
 appropriate header in [RELEASE_NOTES.md](./RELEASE_NOTES.md).
@@ -31,7 +31,7 @@ repositories {
 }

 dependencies {
-    implementation 'com.google.android.filament:filament-android:1.62.0'
+    implementation 'com.google.android.filament:filament-android:1.59.5'
 }
 ```

@@ -51,7 +51,7 @@ Here are all the libraries available in the group `com.google.android.filament`:
 iOS projects can use CocoaPods to install the latest release:

 ```shell
-pod 'Filament', '~> 1.62.0'
+pod 'Filament', '~> 1.59.5'
 ```

 ## Documentation
@@ -7,37 +7,10 @@ A new header is inserted each time a *tag* is created.
 Instead, if you are authoring a PR for the main branch, add your release note to
 [NEW_RELEASE_NOTES.md](./NEW_RELEASE_NOTES.md).

-## v1.62.1
-
- Add new shader define `VARIANT_DEPTH`, defined when a material is compiled for depth variants
-  (e.g., shadows) [**Requires recompiling materials**]
-
-## v1.62.0
-
- Add new `unfilterable` field to Filament Material's `sampler` [⚠️ **New Material Version**]
-
-## v1.61.2
-
- samples: samples now have a CLI to select backend api
-
-## v1.61.1
-
-
-## v1.61.0
-
- materials: sampler now export their type in the material binary [⚠️ **New Material Version**]
- samples/texturedquad.cpp now has CLI to select backend api
- samples/hellopbr.cpp CLI now allows for selecting webgpu
-
-## v1.60.1
-
-
 ## v1.60.0

 - materials: remove dependence on per-view descset layout from filamat. [⚠️ **New Material Version**]
- matc non-functional change: Update GLSL postprocessor to
-  isolate calls to SPVRemap from calls to SPIRV-Cross.
-
+- `ColorGrading::Builder::toneMapper` now takes a `shared_ptr<ToneMapper>`

 ## v1.59.5

@@ -59,10 +59,6 @@ add_library(smol-v STATIC IMPORTED)
 set_target_properties(smol-v PROPERTIES IMPORTED_LOCATION
        ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libsmol-v.a)

-add_library(abseil STATIC IMPORTED)
-set_target_properties(abseil PROPERTIES IMPORTED_LOCATION
-        ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libabseil.a)
-
 if (FILAMENT_ENABLE_FGVIEWER)
    add_library(fgviewer STATIC IMPORTED)
    set_target_properties(fgviewer PROPERTIES IMPORTED_LOCATION
@@ -132,7 +128,6 @@ target_link_libraries(filament-jni
    PRIVATE jnigraphics
    PRIVATE utils
    PRIVATE perfetto
-    PRIVATE abseil

    # libgeometry is PUBLIC because gltfio uses it.
    PUBLIC geometry
@@ -18,6 +18,7 @@

 #include <filament/ColorGrading.h>
 #include <filament/ToneMapper.h>
+#include <memory>

 #include <math/vec3.h>
 #include <math/vec4.h>
@@ -67,8 +68,9 @@ extern "C" JNIEXPORT void JNICALL
 Java_com_google_android_filament_ColorGrading_nBuilderToneMapper(JNIEnv*, jclass,
        jlong nativeBuilder, jlong toneMapper_) {
    ColorGrading::Builder* builder = (ColorGrading::Builder*) nativeBuilder;
-    const ToneMapper* toneMapper = (const ToneMapper*) toneMapper_;
-    builder->toneMapper(toneMapper);
+    ToneMapper* toneMapper = reinterpret_cast<ToneMapper*>(toneMapper_);
+    std::shared_ptr<ToneMapper> toneMapperCopy(toneMapper->clone());
+    builder->toneMapper(toneMapperCopy);
 }

 #pragma clang diagnostic push
@@ -556,8 +556,7 @@ extern "C" JNIEXPORT void JNICALL Java_com_google_android_filament_Engine_nSetBu
        jlong resourceAllocatorCacheSizeMB, jlong resourceAllocatorCacheMaxAge,
        jboolean disableHandleUseAfterFreeCheck,
        jint preferredShaderLanguage,
-        jboolean forceGLES2Context, jboolean assertNativeWindowIsValid,
-        jint gpuContextPriority) {
+        jboolean forceGLES2Context, jboolean assertNativeWindowIsValid) {
    Engine::Builder* builder = (Engine::Builder*) nativeBuilder;
    Engine::Config config = {
            .commandBufferSizeMB = (uint32_t) commandBufferSizeMB,
@@ -575,7 +574,6 @@ extern "C" JNIEXPORT void JNICALL Java_com_google_android_filament_Engine_nSetBu
            .preferredShaderLanguage = (Engine::Config::ShaderLanguage) preferredShaderLanguage,
            .forceGLES2Context = (bool) forceGLES2Context,
            .assertNativeWindowIsValid = (bool) assertNativeWindowIsValid,
-            .gpuContextPriority = (Engine::GpuContextPriority) gpuContextPriority,
    };
    builder->config(&config);
 }
@@ -214,9 +214,9 @@ public class ColorGrading {
         *
         * The default tone mapping operator is {@link ToneMapper.ACESLegacy}.
         *
-         * The specified tone mapper must have a lifecycle that exceeds the lifetime of
-         * this builder. Since the build(Engine&) method is synchronous, it is safe to
-         * delete the tone mapper object after that finishes executing.
+         * The copy of the specified tone mapper is set to this builder. It is safe to delete
+         * the original tone mapper object while the copied one is held by the built ColorGrading
+         * object.
         *
         * @param toneMapper The tone mapping operator to apply to the HDR color buffer
         *
@@ -175,36 +175,6 @@ public class Engine {
        MULTIVIEW,
    };

-    /**
-     * This controls the priority level for GPU work scheduling, which helps prioritize the
-     * submitted GPU work and enables preemption.
-     */
-    public enum GpuContextPriority {
-        /**
-         * Backend default GPU context priority (typically MEDIUM)
-         */
-        DEFAULT,
-        /**
-         * For non-interactive, deferrable workloads. This should not interfere with standard
-         * applications.
-         */
-        LOW,
-        /**
-         * The default priority level for standard applications.
-         */
-        MEDIUM,
-        /**
-         * For high-priority, latency-sensitive workloads that are more important than standard
-         * applications.
-         */
-        HIGH,
-        /**
-         * The highest priority, intended for system-critical, real-time applications where missing
-         * deadlines is unacceptable (e.g., VR/AR compositors or other system-critical tasks).
-         */
-        REALTIME,
-    };
-
    /**
     * Constructs <code>Engine</code> objects using a builder pattern.
     */
@@ -263,8 +233,7 @@ public class Engine {
                    config.resourceAllocatorCacheSizeMB, config.resourceAllocatorCacheMaxAge,
                    config.disableHandleUseAfterFreeCheck,
                    config.preferredShaderLanguage.ordinal(),
-                    config.forceGLES2Context, config.assertNativeWindowIsValid,
-                    config.gpuContextPriority.ordinal());
+                    config.forceGLES2Context, config.assertNativeWindowIsValid);
            return this;
        }

@@ -520,11 +489,6 @@ public class Engine {
         * @Deprecated use "backend.opengl.assert_native_window_is_valid" feature flag instead
         */
        public boolean assertNativeWindowIsValid = false;
-
-        /**
-         * GPU context priority level. Controls GPU work scheduling and preemption.
-         */
-        public GpuContextPriority gpuContextPriority = GpuContextPriority.DEFAULT;
    }

    private Engine(long nativeEngine, Config config) {
@@ -1528,8 +1492,7 @@ public class Engine {
            long resourceAllocatorCacheSizeMB, long resourceAllocatorCacheMaxAge,
            boolean disableHandleUseAfterFreeCheck,
            int preferredShaderLanguage,
-            boolean forceGLES2Context, boolean assertNativeWindowIsValid,
-            int gpuContextPriority);
+            boolean forceGLES2Context, boolean assertNativeWindowIsValid);
    private static native void nSetBuilderFeatureLevel(long nativeBuilder, int ordinal);
    private static native void nSetBuilderSharedContext(long nativeBuilder, long sharedContext);
    private static native void nSetBuilderPaused(long nativeBuilder, boolean paused);
@@ -1801,22 +1801,6 @@ public class View {
     * @see setAmbientOcclusionOptions()
     */
    public static class AmbientOcclusionOptions {
-        public enum AmbientOcclusionType {
-            /**
-             * use Scalable Ambient Occlusion
-             */
-            SAO,
-            /**
-             * use Ground Truth-Based Ambient Occlusion
-             */
-            GTAO,
-        }
-
-        /**
-         * Type of ambient occlusion algorithm.
-         */
-        @NonNull
-        public AmbientOcclusionOptions.AmbientOcclusionType aoType = AmbientOcclusionOptions.AmbientOcclusionType.SAO;
        /**
         * Ambient Occlusion radius in meters, between 0 and ~10.
         */
@@ -1826,8 +1810,7 @@ public class View {
         */
        public float power = 1.0f;
        /**
-         * Self-occlusion bias in meters. Use to avoid self-occlusion.
-         * Between 0 and a few mm. No effect when aoType set to GTAO
+         * Self-occlusion bias in meters. Use to avoid self-occlusion. Between 0 and a few mm.
         */
        public float bias = 0.0005f;
        /**
@@ -1843,12 +1826,12 @@ public class View {
         */
        public float bilateralThreshold = 0.05f;
        /**
-         * affects # of samples used for AO and params for filtering
+         * affects # of samples used for AO.
         */
        @NonNull
        public QualityLevel quality = QualityLevel.LOW;
        /**
-         * affects AO smoothness. Recommend setting to HIGH when aoType set to GTAO.
+         * affects AO smoothness
         */
        @NonNull
        public QualityLevel lowPassFilter = QualityLevel.MEDIUM;
@@ -1866,7 +1849,7 @@ public class View {
         */
        public boolean bentNormals = false;
        /**
-         * min angle in radian to consider. No effect when aoType set to GTAO.
+         * min angle in radian to consider
         */
        public float minHorizonAngleRad = 0.0f;
        /**
@@ -1921,19 +1904,6 @@ public class View {
         */
        public boolean ssctEnabled = false;

-        /**
-         * Ground Truth-base Ambient Occlusion (GTAO) options
-         */
-        public int gtaoSampleSliceCount = 4;
-        /**
-         * Ground Truth-base Ambient Occlusion (GTAO) options
-         */
-        public int gtaoSampleStepsPerSlice = 3;
-        /**
-         * Ground Truth-base Ambient Occlusion (GTAO) options
-         */
-        public float gtaoThicknessHeuristic = 0.004f;
-
    }

    /**
@@ -1,5 +1,5 @@
 GROUP=com.google.android.filament
-VERSION_NAME=1.62.0
+VERSION_NAME=1.59.5

 POM_DESCRIPTION=Real-time physically based rendering engine for Android.

@@ -1,7 +1,6 @@
+#Wed Nov 17 10:40:18 PST 2021
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 distributionUrl=https\://services.gradle.org/distributions/gradle-8.8-bin.zip
-networkTimeout=10000
-validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
@@ -1,7 +1,7 @@
-#!/bin/sh
+#!/usr/bin/env sh

 #
-# Copyright © 2015-2021 the original authors.
+# Copyright 2015 the original author or authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -17,99 +17,67 @@
 #

 ##############################################################################
-#
-#   Gradle start up script for POSIX generated by Gradle.
-#
-#   Important for running:
-#
-#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
-#       noncompliant, but you have some other compliant shell such as ksh or
-#       bash, then to run this script, type that shell name before the whole
-#       command line, like:
-#
-#           ksh Gradle
-#
-#       Busybox and similar reduced shells will NOT work, because this script
-#       requires all of these POSIX shell features:
-#         * functions;
-#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
-#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
-#         * compound commands having a testable exit status, especially «case»;
-#         * various built-in commands including «command», «set», and «ulimit».
-#
-#   Important for patching:
-#
-#   (2) This script targets any POSIX shell, so it avoids extensions provided
-#       by Bash, Ksh, etc; in particular arrays are avoided.
-#
-#       The "traditional" practice of packing multiple parameters into a
-#       space-separated string is a well documented source of bugs and security
-#       problems, so this is (mostly) avoided, by progressively accumulating
-#       options in "$@", and eventually passing that to Java.
-#
-#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
-#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
-#       see the in-line comments for details.
-#
-#       There are tweaks for specific operating systems such as AIX, CygWin,
-#       Darwin, MinGW, and NonStop.
-#
-#   (3) This script is generated from the Groovy template
-#       https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
-#       within the Gradle project.
-#
-#       You can find Gradle at https://github.com/gradle/gradle/.
-#
+##
+##  Gradle start up script for UN*X
+##
 ##############################################################################

 # Attempt to set APP_HOME
-
 # Resolve links: $0 may be a link
-app_path=$0
-
-# Need this for daisy-chained symlinks.
-while
-    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
-    [ -h "$app_path" ]
-do
-    ls=$( ls -ld "$app_path" )
-    link=${ls#*' -> '}
-    case $link in             #(
-      /*)   app_path=$link ;; #(
-      *)    app_path=$APP_HOME$link ;;
-    esac
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
 done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null

-# This is normally unused
-# shellcheck disable=SC2034
-APP_BASE_NAME=${0##*/}
-# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
-APP_HOME=$( cd "${APP_HOME:-./}" > /dev/null && pwd -P ) || exit
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'

 # Use the maximum available, or set MAX_FD != -1 to use that value.
-MAX_FD=maximum
+MAX_FD="maximum"

 warn () {
    echo "$*"
-} >&2
+}

 die () {
    echo
    echo "$*"
    echo
    exit 1
-} >&2
+}

 # OS specific support (must be 'true' or 'false').
 cygwin=false
 msys=false
 darwin=false
 nonstop=false
-case "$( uname )" in                #(
-  CYGWIN* )         cygwin=true  ;; #(
-  Darwin* )         darwin=true  ;; #(
-  MSYS* | MINGW* )  msys=true    ;; #(
-  NONSTOP* )        nonstop=true ;;
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
 esac

 CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
@@ -119,9 +87,9 @@ CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 if [ -n "$JAVA_HOME" ] ; then
    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
        # IBM's JDK on AIX uses strange locations for the executables
-        JAVACMD=$JAVA_HOME/jre/sh/java
+        JAVACMD="$JAVA_HOME/jre/sh/java"
    else
-        JAVACMD=$JAVA_HOME/bin/java
+        JAVACMD="$JAVA_HOME/bin/java"
    fi
    if [ ! -x "$JAVACMD" ] ; then
        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
@@ -130,120 +98,88 @@ Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
    fi
 else
-    JAVACMD=java
-    if ! command -v java >/dev/null 2>&1
-    then
-        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.

 Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
-    fi
 fi

 # Increase the maximum file descriptors if we can.
-if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
-    case $MAX_FD in #(
-      max*)
-        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC2039,SC3045
-        MAX_FD=$( ulimit -H -n ) ||
-            warn "Could not query maximum file descriptor limit"
-    esac
-    case $MAX_FD in  #(
-      '' | soft) :;; #(
-      *)
-        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC2039,SC3045
-        ulimit -n "$MAX_FD" ||
-            warn "Could not set maximum file descriptor limit to $MAX_FD"
-    esac
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
 fi

-# Collect all arguments for the java command, stacking in reverse order:
-#   * args from the command line
-#   * the main class name
-#   * -classpath
-#   * -D...appname settings
-#   * --module-path (only if needed)
-#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi

 # For Cygwin or MSYS, switch paths to Windows format before running java
-if "$cygwin" || "$msys" ; then
-    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
-    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`

-    JAVACMD=$( cygpath --unix "$JAVACMD" )
+    JAVACMD=`cygpath --unix "$JAVACMD"`

-    # Now convert the arguments - kludge to limit ourselves to /bin/sh
-    for arg do
-        if
-            case $arg in                                #(
-              -*)   false ;;                            # don't mess with options #(
-              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
-                    [ -e "$t" ] ;;                      #(
-              *)    false ;;
-            esac
-        then
-            arg=$( cygpath --path --ignore --mixed "$arg" )
-        fi
-        # Roll the args list around exactly as many times as the number of
-        # args, so each arg winds up back in the position where it started, but
-        # possibly modified.
-        #
-        # NB: a `for` loop captures its iteration list before it begins, so
-        # changing the positional parameters here affects neither the number of
-        # iterations, nor the values presented in `arg`.
-        shift                   # remove old arg
-        set -- "$@" "$arg"      # push replacement arg
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=`expr $i + 1`
+    done
+    case $i in
+        0) set -- ;;
+        1) set -- "$args0" ;;
+        2) set -- "$args0" "$args1" ;;
+        3) set -- "$args0" "$args1" "$args2" ;;
+        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
 fi

+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=`save "$@"`

-# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
-
-# Collect all arguments for the java command:
-#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
-#     and any embedded shellness will be escaped.
-#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
-#     treated as '${Hostname}' itself on the command line.
-
-set -- \
-        "-Dorg.gradle.appname=$APP_BASE_NAME" \
-        -classpath "$CLASSPATH" \
-        org.gradle.wrapper.GradleWrapperMain \
-        "$@"
-
-# Stop when "xargs" is not available.
-if ! command -v xargs >/dev/null 2>&1
-then
-    die "xargs is not available"
-fi
-
-# Use "xargs" to parse quoted args.
-#
-# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
-#
-# In Bash we could simply go:
-#
-#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
-#   set -- "${ARGS[@]}" "$@"
-#
-# but POSIX shell has neither arrays nor command substitution, so instead we
-# post-process each arg (as a line of input to sed) to backslash-escape any
-# character that might be a shell metacharacter, then use eval to reverse
-# that process (while maintaining the separation between arguments), and wrap
-# the whole thing up as a single "set" statement.
-#
-# This will of course break if any of these variables contains a newline or
-# an unmatched quote.
-#
-
-eval "set -- $(
-        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
-        xargs -n1 |
-        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
-        tr '\n' ' '
-    )" '"$@"'
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"

 exec "$JAVACMD" "$@"
@@ -14,7 +14,7 @@
@rem limitations under the License.
@rem

-@if "%DEBUG%"=="" @echo off
+@if "%DEBUG%" == "" @echo off
@rem ##########################################################################
@rem
@rem  Gradle startup script for Windows
@@ -25,8 +25,7 @@
 if "%OS%"=="Windows_NT" setlocal

 set DIRNAME=%~dp0
-if "%DIRNAME%"=="" set DIRNAME=.
-@rem This is normally unused
+if "%DIRNAME%" == "" set DIRNAME=.
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%

@@ -41,13 +40,13 @@ if defined JAVA_HOME goto findJavaFromJavaHome

 set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
-if %ERRORLEVEL% equ 0 goto execute
+if "%ERRORLEVEL%" == "0" goto execute

-echo. 1>&2
-echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
-echo. 1>&2
-echo Please set the JAVA_HOME variable in your environment to match the 1>&2
-echo location of your Java installation. 1>&2
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.

 goto fail

@@ -57,11 +56,11 @@ set JAVA_EXE=%JAVA_HOME%/bin/java.exe

 if exist "%JAVA_EXE%" goto execute

-echo. 1>&2
-echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
-echo. 1>&2
-echo Please set the JAVA_HOME variable in your environment to match the 1>&2
-echo location of your Java installation. 1>&2
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.

 goto fail

@@ -76,15 +75,13 @@ set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar

 :end
@rem End local scope for the variables with windows NT shell
-if %ERRORLEVEL% equ 0 goto mainEnd
+if "%ERRORLEVEL%"=="0" goto mainEnd

 :fail
 rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
 rem the _cmd.exe /c_ return code!
-set EXIT_CODE=%ERRORLEVEL%
-if %EXIT_CODE% equ 0 set EXIT_CODE=1
-if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
-exit /b %EXIT_CODE%
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1

 :mainEnd
 if "%OS%"=="Windows_NT" endlocal
@@ -18,7 +18,6 @@ package com.google.android.filament.gltf

 import android.annotation.SuppressLint
 import android.app.Activity
-import android.content.Intent
 import android.os.Bundle
 import android.util.Log
 import android.view.*
@@ -51,7 +50,6 @@ class MainActivity : Activity() {
        // Load the library for the utility layer, which in turn loads gltfio and the Filament core.
        init { Utils.init() }
        private const val TAG = "gltf-viewer"
-        private const val STATIC_MODEL_TAG = "use-static-model"
    }

    private lateinit var surfaceView: SurfaceView
@@ -71,7 +69,6 @@ class MainActivity : Activity() {
    private var loadStartTime = 0L
    private var loadStartFence: Fence? = null
    private val viewerContent = AutomationEngine.ViewerContent()
-    private var useStaticModel = false

    @SuppressLint("ClickableViewAccessibility")
    override fun onCreate(savedInstanceState: Bundle?) {
@@ -86,12 +83,6 @@ class MainActivity : Activity() {
        doubleTapDetector = GestureDetector(applicationContext, doubleTapListener)
        singleTapDetector = GestureDetector(applicationContext, singleTapListener)

-        val intent: Intent = intent
-        val bundle: Bundle? = intent.extras
-        bundle?.let {
-            useStaticModel = it.getBoolean(STATIC_MODEL_TAG, false)
-        }
-
        modelViewer = ModelViewer(surfaceView)
        viewerContent.view = modelViewer.view
        viewerContent.sunlight = modelViewer.light
@@ -150,16 +141,7 @@ class MainActivity : Activity() {
    }

    private fun createDefaultRenderables() {
-        // Sometimes it's useful to set to the default model to something static. You can enable
-        // the static model by launching the app from adb, as in
-        // `adb shell am start -n com.google.android.filament.gltf/.MainActivity --ez "use-static-model" true`
-        val modelPath = if (useStaticModel) {
-            "models/helmet.glb"
-        } else {
-            "models/scene.gltf"
-        }
-
-        val buffer = assets.open(modelPath).use { input ->
+        val buffer = assets.open("models/scene.gltf").use { input ->
            val bytes = ByteArray(input.available())
            input.read(bytes)
            ByteBuffer.wrap(bytes)
@@ -151,7 +151,7 @@ function print_fgviewer_help {
 }

 # Unless explicitly specified, NDK version will be selected as highest available version within same major release chain
-FILAMENT_NDK_VERSION=${FILAMENT_NDK_VERSION:-$(cat `dirname $0`/build/common/versions | grep GITHUB_NDK_VERSION | sed s/GITHUB_NDK_VERSION=//g | cut -f 1 -d ".")}
+FILAMENT_NDK_VERSION=${FILAMENT_NDK_VERSION:-$(cat `dirname $0`/build/common/versions | grep GITHUB_NDK_VERSION | cut -f 1 -d ".")}

 # Requirements
 CMAKE_MAJOR=3
@@ -463,6 +463,16 @@ function ensure_android_build {
        echo "Error: Android NDK side-by-side version ${FILAMENT_NDK_VERSION} or compatible must be installed, exiting"
        exit 1
    fi
+
+    local cmake_version=$(cmake --version)
+    if [[ "${cmake_version}" =~ ([0-9]+)\.([0-9]+)\.[0-9]+ ]]; then
+        if [[ "${BASH_REMATCH[1]}" -lt "${CMAKE_MAJOR}" ]] || \
+           [[ "${BASH_REMATCH[2]}" -lt "${CMAKE_MINOR}" ]]; then
+            echo "Error: cmake version ${CMAKE_MAJOR}.${CMAKE_MINOR}+ is required," \
+                 "${BASH_REMATCH[1]}.${BASH_REMATCH[2]} installed, exiting"
+            exit 1
+        fi
+    fi
 }

 function build_android {
@@ -204,10 +204,9 @@
      "license": "Apache-2.0"
    },
    "node_modules/brace-expansion": {
-      "version": "1.1.12",
-      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.12.tgz",
-      "integrity": "sha512-9T9UjW3r0UW5c1Q7GTwllptXwhvYmEzFhzMfZ9H7FQWt+uZePjZPjBP/W1ZEyZ1twGWom5/56TF4lPcqjnDHcg==",
-      "license": "MIT",
+      "version": "1.1.11",
+      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.11.tgz",
+      "integrity": "sha512-iCuPHDFgrHX7H2vEI/5xpz07zSHB00TpugqhmYtVmMO6518mCuRMoOYFldEBl0g187ufozdaHgWKcYFb61qGiA==",
      "dependencies": {
        "balanced-match": "^1.0.0",
        "concat-map": "0.0.1"
@@ -410,9 +409,9 @@
      "integrity": "sha512-Nik3Sc0ncrMK4UUdXQmAnRtzmNQTAAXmXIopizwZ1W1t8QmfJj+zL4OA2I7XPTPW5z5TDqv4hRo/JzouDJnX3A=="
    },
    "brace-expansion": {
-      "version": "1.1.12",
-      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.12.tgz",
-      "integrity": "sha512-9T9UjW3r0UW5c1Q7GTwllptXwhvYmEzFhzMfZ9H7FQWt+uZePjZPjBP/W1ZEyZ1twGWom5/56TF4lPcqjnDHcg==",
+      "version": "1.1.11",
+      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.11.tgz",
+      "integrity": "sha512-iCuPHDFgrHX7H2vEI/5xpz07zSHB00TpugqhmYtVmMO6518mCuRMoOYFldEBl0g187ufozdaHgWKcYFb61qGiA==",
      "requires": {
        "balanced-match": "^1.0.0",
        "concat-map": "0.0.1"
@@ -47,11 +47,7 @@ if "%RUNNING_LOCALLY%" == "1" (
    set "PATH=%PATH%;C:\Program Files\7-Zip"
 )

-:: Outdated windows-2019 pattern
-:: call "C:\Program Files (x86)\Microsoft Visual Studio\2019\%VISUAL_STUDIO_VERSION%\VC\Auxiliary\Build\vcvars64.bat"
-
-call "C:\Program Files\Microsoft Visual Studio\2022\%VISUAL_STUDIO_VERSION%\VC\Auxiliary\Build\vcvars64.bat"
-echo Passed vcvars64.bat
+call "C:\Program Files (x86)\Microsoft Visual Studio\2019\%VISUAL_STUDIO_VERSION%\VC\Auxiliary\Build\vcvars64.bat"
 if errorlevel 1 exit /b %errorlevel%

 msbuild /version
@@ -111,7 +107,7 @@ cd out\cmake-%variant%
 if errorlevel 1 exit /b %errorlevel%

 cmake ..\.. ^
-    -G "Visual Studio 17 2022" ^
+    -G "Visual Studio 16 2019" ^
    -A x64 ^
    %flag% ^
    -DCMAKE_INSTALL_PREFIX=..\%variant% ^
@@ -1027,11 +1027,8 @@ samplerCubemap         | Cubemap texture
 [Table [materialParamsTypes]: Material parameter types]

 Samplers
-:     Sampler types can have the following fields:
-       - `format` : which can be either `int` or `float` (defaults to `float`).
-       - `multisample` : a boolean to indicate whether the sampler is meant for multisampling (defaults to `false`)
-       - `unfilterable` : a boolean to indicate whether the sampling is not filtered (defaults to `false`)
-
+:     Sampler types can also specify a `format` which can be either `int` or `float` (defaults to
+      `float`).

 Arrays
 :     A parameter can define an array of values by appending `[size]` after the type name, where
@@ -30,6 +30,11 @@ from utils import execute, ArgParseImpl
 CUR_DIR = os.path.dirname(os.path.abspath(__file__))
 ROOT_DIR = os.path.join(CUR_DIR, '../../')

+def get_last_commit_hash():
+  res, ret = execute('git rev-parse HEAD', cwd=ROOT_DIR)
+  assert res == 0, 'Failed to get the last commit hash'
+  return ret.strip()
+
 def get_edited_files(commit_hash):
  INSERT = '#####?????'
  res, ret = execute(f'git show --name-only --pretty=%b{INSERT} {commit_hash}')
@@ -39,13 +39,13 @@ function download_mdbook() {
    fi

    local CHECK_UNAME="
-import sys
-parts=[a.lower() for a in sys.stdin.read().strip().split(' ')]
+import sys;
+parts=[a.lower() for a in sys.stdin.read().strip().split(' ')];
 def get_type():
  if 'darwin' in parts:
    if 'x86_64' in parts:
      return ${DARWIN_X86}
-    elif 'aarch' in parts or 'arm64' in parts:
+    elif 'aarch' in parts:
      return ${DARWIN_ARM}
  elif 'linux' in parts:
    if 'x86_64' in parts:
@@ -63,12 +63,11 @@ print(get_type())
            echo "*** Need to install Rust ***"
            curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
        fi
-        source "${HOME}/.cargo/env"
        if ! (command -v cargo >/dev/null 2>&1); then
-            echo "*** Still cannot find cargo ***"
+            echo "*** Still cannot find `cargo` ***"
            exit 1
        fi
-        cargo install --force mdbook
+        cargo install mdbook
    else
        # Download prebuilts from github
        mkdir -p ${HOME}/.cargo/bin
@@ -13,7 +13,7 @@ This document is part of the [Filament project](https://github.com/google/filame
 ## Authors

 - [Romain Guy](https://github.com/romainguy), [@romainguy](https://twitter.com/romainguy)
- [Mathias Agopian](https://github.com/pixelflinger), [@pixelflinger](https://bsky.app/profile/pixelflinger.bsky.social)
+- [Mathias Agopian](https://github.com/pixelflinger), [@darthmoosious](https://twitter.com/darthmoosious)

 # Overview

@@ -78,27 +78,26 @@ in table [standardProperties].
        Property        |      Definition
 -----------------------:|:---------------------
 **baseColor**           | Diffuse albedo for non-metallic surfaces, and specular color for metallic surfaces
-**roughness**           | Perceived smoothness (1.0) or roughness (0.0) of a surface. Smooth surfaces exhibit sharp reflections
 **metallic**            | Whether a surface appears to be dielectric (0.0) or conductor (1.0). Often used as a binary value (0 or 1)
+**roughness**           | Perceived smoothness (1.0) or roughness (0.0) of a surface. Smooth surfaces exhibit sharp reflections
 **reflectance**         | Fresnel reflectance at normal incidence for dielectric surfaces. This directly controls the strength of the reflections
-**ambientOcclusion**    | Defines how much of the ambient light is accessible to a surface point. It is a per-pixel shadowing factor between 0.0 and 1.0
-**clearCoat**           | Strength of the clear coat layer
-**clearCoatRoughness**  | Perceived smoothness or roughness of the clear coat layer
-**clearCoatNormal**     | A detail normal used to perturb the clear coat layer using _bump mapping_ (_normal mapping_)
-**anisotropy**          | Amount of anisotropy in either the tangent or bitangent direction
-**anisotropyDirection** | Local surface direction in tangent space
-**thickness**           | Thickness of the solid volume of refractive objects
 **sheenColor**          | Strength of the sheen layer
 **sheenRoughness**      | Perceived smoothness or roughness of the sheen layer
-**emissive**            | Additional diffuse albedo to simulate emissive surfaces (such as neons, etc.) This property is mostly useful in an HDR pipeline with a bloom pass
+**clearCoat**           | Strength of the clear coat layer
+**clearCoatRoughness**  | Perceived smoothness or roughness of the clear coat layer
+**anisotropy**          | Amount of anisotropy in either the tangent or bitangent direction
+**anisotropyDirection** | Local surface direction in tangent space
+**ambientOcclusion**    | Defines how much of the ambient light is accessible to a surface point. It is a per-pixel shadowing factor between 0.0 and 1.0
 **normal**              | A detail normal used to perturb the surface using _bump mapping_ (_normal mapping_)
-**postLightingColor**   | Additional color that can be blended with the result of the lighting computations. See `postLightingBlending`
-**absorption**          | Absorption factor for refractive objects
-**transmission**        | Defines how much of the diffuse light of a dielectric is transmitted through the object, in other words this defines how transparent an object is
-**ior**                 | Index of refraction, either for refractive objects or as an alternative to reflectance
-**microThickness**      | Thickness of the thin layer of refractive objects
 **bentNormal**          | A normal pointing in the average unoccluded direction. Can be used to improve indirect lighting quality
-**shadowStrength**      | Strength factor between 0 and 1 for all shadows received by this material
+**clearCoatNormal**     | A detail normal used to perturb the clear coat layer using _bump mapping_ (_normal mapping_)
+**emissive**            | Additional diffuse albedo to simulate emissive surfaces (such as neons, etc.) This property is mostly useful in an HDR pipeline with a bloom pass
+**postLightingColor**   | Additional color that can be blended with the result of the lighting computations. See `postLightingBlending`
+**ior**                 | Index of refraction, either for refractive objects or as an alternative to reflectance
+**transmission**        | Defines how much of the diffuse light of a dielectric is transmitted through the object, in other words this defines how transparent an object is
+**absorption**          | Absorption factor for refractive objects
+**microThickness**      | Thickness of the thin layer of refractive objects
+**thickness**           | Thickness of the solid volume of refractive objects
 [Table [standardProperties]: Properties of the standard model]

 The type and range of each property is described in table [standardPropertiesTypes].
@@ -992,13 +991,10 @@ Type

 Value
 :     Each entry is an object with the properties `name` and `type`, both of `string` type. The
-      name must be a valid GLSL identifier. Entries have an optional `precision`, which can be
+      name must be a valid GLSL identifier. Entries also have an optional `precision`, which can be
      one of `default` (best precision for the platform, typically `high` on desktop, `medium` on
      mobile), `low`, `medium`, `high`. The type must be one of the types described in
-      table [materialParamsTypes]. For Android external textures, entries also have an optional 
-      transformName parameter to specify the name of the material parameter that will be 
-      used to expose the transform matrix associated with the external sampler. In iOS and Vulkan,
-      this will always be identity. 
+      table [materialParamsTypes].

         Type          |            Description
 :----------------------|:---------------------------------
@@ -1273,9 +1269,6 @@ Description
      when selecting any shading model that is not `unlit`. See the shader sections of this document
      for more information on how to access these attributes from the shaders.

-!!! Note: Interaction with custom variables
-    When the `color` attribute is specified, only four custom variables are available instead of five.
-
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ JSON
 material {
    parameters : [
@@ -1306,7 +1299,7 @@ Type
 :    array of `string`

 Value
-:     Up to 5 strings, each must be a valid GLSL identifier.
+:     Up to 4 strings, each must be a valid GLSL identifier.

 Description
 :     Defines custom interpolants (or variables) that are output by the material's vertex shader.
@@ -1322,10 +1315,6 @@ Description
      particular if `default` is specified the default precision is used is the fragment shader
      (`mediump`) and in the vertex shader (`highp`).

-!!! Warning: Interaction with required attributes
-    If the `color` attribute is specified in the `required` list, then only four variables can be used
-    instead of five.
-
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ JSON
 material {
    name : Skybox,
@@ -19,7 +19,6 @@
    - [Vulkan](./notes/vulkan_debugging.md)
    - [SPIR-V](./notes/spirv_debugging.md)
    - [Running with ASAN and UBSAN](./notes/asan_ubsan.md)
-    - [Using Instruments on macOS](./notes/instruments.md)
  - [Libraries](./notes/libs.md)
    - [bluegl](./dup/bluegl.md)
    - [bluevk](./dup/bluevk.md)
@@ -146,7 +146,7 @@ This document is part of the <a href="https://github.com/google/filament">Filame
 <ul>
 <li class="minus"><a href="https://github.com/romainguy">Romain Guy</a>, <a href="https://twitter.com/romainguy">@romainguy</a>
 </li>
-<li class="minus"><a href="https://github.com/pixelflinger">Mathias Agopian</a>, <a href="https://bsky.app/profile/pixelflinger.bsky.social">@pixelflinger</a></li></ul>
+<li class="minus"><a href="https://github.com/pixelflinger">Mathias Agopian</a>, <a href="https://twitter.com/darthmoosious">@darthmoosious</a></li></ul>
 </p>
 <a class="target" name="overview">&nbsp;</a><a class="target" name="overview">&nbsp;</a><a class="target" name="toc2">&nbsp;</a><h1>Overview</h1>
 <p>
@@ -217,27 +217,26 @@ in <a href="#table_standardproperties" target="_self">table&nbsp;1</a>.
 <div class='table'>
 <a class="target" name="table_standardproperties">&nbsp;</a><table class="table longtable"><tr><th  style="text-align:right"> Property </th><th  style="text-align:left"> Definition </th></tr>
 <tr><td  style="text-align:right"> <strong class="asterisk">baseColor</strong> </td><td  style="text-align:left"> Diffuse albedo for non-metallic surfaces, and specular color for metallic surfaces </td></tr>
-<tr><td  style="text-align:right"> <strong class="asterisk">roughness</strong> </td><td  style="text-align:left"> Perceived smoothness (1.0) or roughness (0.0) of a surface. Smooth surfaces exhibit sharp reflections </td></tr>
 <tr><td  style="text-align:right"> <strong class="asterisk">metallic</strong> </td><td  style="text-align:left"> Whether a surface appears to be dielectric (0.0) or conductor (1.0). Often used as a binary value (0 or 1) </td></tr>
+<tr><td  style="text-align:right"> <strong class="asterisk">roughness</strong> </td><td  style="text-align:left"> Perceived smoothness (1.0) or roughness (0.0) of a surface. Smooth surfaces exhibit sharp reflections </td></tr>
 <tr><td  style="text-align:right"> <strong class="asterisk">reflectance</strong> </td><td  style="text-align:left"> Fresnel reflectance at normal incidence for dielectric surfaces. This directly controls the strength of the reflections </td></tr>
-<tr><td  style="text-align:right"> <strong class="asterisk">ambientOcclusion</strong> </td><td  style="text-align:left"> Defines how much of the ambient light is accessible to a surface point. It is a per-pixel shadowing factor between 0.0 and 1.0 </td></tr>
-<tr><td  style="text-align:right"> <strong class="asterisk">clearCoat</strong> </td><td  style="text-align:left"> Strength of the clear coat layer </td></tr>
-<tr><td  style="text-align:right"> <strong class="asterisk">clearCoatRoughness</strong> </td><td  style="text-align:left"> Perceived smoothness or roughness of the clear coat layer </td></tr>
-<tr><td  style="text-align:right"> <strong class="asterisk">clearCoatNormal</strong> </td><td  style="text-align:left"> A detail normal used to perturb the clear coat layer using <em class="underscore">bump mapping</em> (<em class="underscore">normal mapping</em>) </td></tr>
-<tr><td  style="text-align:right"> <strong class="asterisk">anisotropy</strong> </td><td  style="text-align:left"> Amount of anisotropy in either the tangent or bitangent direction </td></tr>
-<tr><td  style="text-align:right"> <strong class="asterisk">anisotropyDirection</strong> </td><td  style="text-align:left"> Local surface direction in tangent space </td></tr>
-<tr><td  style="text-align:right"> <strong class="asterisk">thickness</strong> </td><td  style="text-align:left"> Thickness of the solid volume of refractive objects </td></tr>
 <tr><td  style="text-align:right"> <strong class="asterisk">sheenColor</strong> </td><td  style="text-align:left"> Strength of the sheen layer </td></tr>
 <tr><td  style="text-align:right"> <strong class="asterisk">sheenRoughness</strong> </td><td  style="text-align:left"> Perceived smoothness or roughness of the sheen layer </td></tr>
-<tr><td  style="text-align:right"> <strong class="asterisk">emissive</strong> </td><td  style="text-align:left"> Additional diffuse albedo to simulate emissive surfaces (such as neons, etc.) This property is mostly useful in an HDR pipeline with a bloom pass </td></tr>
+<tr><td  style="text-align:right"> <strong class="asterisk">clearCoat</strong> </td><td  style="text-align:left"> Strength of the clear coat layer </td></tr>
+<tr><td  style="text-align:right"> <strong class="asterisk">clearCoatRoughness</strong> </td><td  style="text-align:left"> Perceived smoothness or roughness of the clear coat layer </td></tr>
+<tr><td  style="text-align:right"> <strong class="asterisk">anisotropy</strong> </td><td  style="text-align:left"> Amount of anisotropy in either the tangent or bitangent direction </td></tr>
+<tr><td  style="text-align:right"> <strong class="asterisk">anisotropyDirection</strong> </td><td  style="text-align:left"> Local surface direction in tangent space </td></tr>
+<tr><td  style="text-align:right"> <strong class="asterisk">ambientOcclusion</strong> </td><td  style="text-align:left"> Defines how much of the ambient light is accessible to a surface point. It is a per-pixel shadowing factor between 0.0 and 1.0 </td></tr>
 <tr><td  style="text-align:right"> <strong class="asterisk">normal</strong> </td><td  style="text-align:left"> A detail normal used to perturb the surface using <em class="underscore">bump mapping</em> (<em class="underscore">normal mapping</em>) </td></tr>
-<tr><td  style="text-align:right"> <strong class="asterisk">postLightingColor</strong> </td><td  style="text-align:left"> Additional color that can be blended with the result of the lighting computations. See <code>postLightingBlending</code> </td></tr>
-<tr><td  style="text-align:right"> <strong class="asterisk">absorption</strong> </td><td  style="text-align:left"> Absorption factor for refractive objects </td></tr>
-<tr><td  style="text-align:right"> <strong class="asterisk">transmission</strong> </td><td  style="text-align:left"> Defines how much of the diffuse light of a dielectric is transmitted through the object, in other words this defines how transparent an object is </td></tr>
-<tr><td  style="text-align:right"> <strong class="asterisk">ior</strong> </td><td  style="text-align:left"> Index of refraction, either for refractive objects or as an alternative to reflectance </td></tr>
-<tr><td  style="text-align:right"> <strong class="asterisk">microThickness</strong> </td><td  style="text-align:left"> Thickness of the thin layer of refractive objects </td></tr>
 <tr><td  style="text-align:right"> <strong class="asterisk">bentNormal</strong> </td><td  style="text-align:left"> A normal pointing in the average unoccluded direction. Can be used to improve indirect lighting quality </td></tr>
-<tr><td  style="text-align:right"> <strong class="asterisk">shadowStrength</strong> </td><td  style="text-align:left"> Strength factor between 0 and 1 for all shadows received by this material </td></tr>
+<tr><td  style="text-align:right"> <strong class="asterisk">clearCoatNormal</strong> </td><td  style="text-align:left"> A detail normal used to perturb the clear coat layer using <em class="underscore">bump mapping</em> (<em class="underscore">normal mapping</em>) </td></tr>
+<tr><td  style="text-align:right"> <strong class="asterisk">emissive</strong> </td><td  style="text-align:left"> Additional diffuse albedo to simulate emissive surfaces (such as neons, etc.) This property is mostly useful in an HDR pipeline with a bloom pass </td></tr>
+<tr><td  style="text-align:right"> <strong class="asterisk">postLightingColor</strong> </td><td  style="text-align:left"> Additional color that can be blended with the result of the lighting computations. See <code>postLightingBlending</code> </td></tr>
+<tr><td  style="text-align:right"> <strong class="asterisk">ior</strong> </td><td  style="text-align:left"> Index of refraction, either for refractive objects or as an alternative to reflectance </td></tr>
+<tr><td  style="text-align:right"> <strong class="asterisk">transmission</strong> </td><td  style="text-align:left"> Defines how much of the diffuse light of a dielectric is transmitted through the object, in other words this defines how transparent an object is </td></tr>
+<tr><td  style="text-align:right"> <strong class="asterisk">absorption</strong> </td><td  style="text-align:left"> Absorption factor for refractive objects </td></tr>
+<tr><td  style="text-align:right"> <strong class="asterisk">microThickness</strong> </td><td  style="text-align:left"> Thickness of the thin layer of refractive objects </td></tr>
+<tr><td  style="text-align:right"> <strong class="asterisk">thickness</strong> </td><td  style="text-align:left"> Thickness of the solid volume of refractive objects </td></tr>
 </table><center><div class="tablecaption"><b style="font-style:normal;">Table&nbsp;1:</b> Properties of the standard model</div></center></div>
 </p><p>
 The type and range of each property is described in <a href="#table_standardpropertiestypes" target="_self">table&nbsp;2</a>.
@@ -1098,13 +1097,10 @@ non-shader data.

 <dl><dt>Type</dt><dd><p>     array of parameter objects
 </p></dd><dt>Value</dt><dd><p>      Each entry is an object with the properties <code>name</code> and <code>type</code>, both of <code>string</code> type. The
-      name must be a valid GLSL identifier. Entries have an optional <code>precision</code>, which can be
+      name must be a valid GLSL identifier. Entries also have an optional <code>precision</code>, which can be
      one of <code>default</code> (best precision for the platform, typically <code>high</code> on desktop, <code>medium</code> on
      mobile), <code>low</code>, <code>medium</code>, <code>high</code>. The type must be one of the types described in
-      <a href="#table_materialparamstypes" target="_self">table&nbsp;14</a>. For Android external textures, entries also have an optional 
-      transformName parameter to specify the name of the material parameter that will be 
-      used to expose the transform matrix associated with the external sampler. In iOS and Vulkan,
-      this will always be identity. 
+      <a href="#table_materialparamstypes" target="_self">table&nbsp;14</a>.
 </p></dd></dl><div class='table'>
 <a class="target" name="table_materialparamstypes">&nbsp;</a><table class="table longtable"><tr><th  style="text-align:left"> Type </th><th  style="text-align:left"> Description </th></tr>
 <tr><td  style="text-align:left"> bool </td><td  style="text-align:left"> Single boolean </td></tr>
@@ -1326,10 +1322,7 @@ non-shader data.
      required and does not need to be specified. The <code>tangents</code> attribute is automatically required
      when selecting any shading model that is not <code>unlit</code>. See the shader sections of this document
      for more information on how to access these attributes from the shaders.
-</p></dd></dl><div class="admonition note"><div class="admonition-title"> Interaction with custom variables</div>
-</p><p>
-    When the <code>color</code> attribute is specified, only four custom variables are available instead of five.</div>
-</p><pre class="listing tilde"><code><span class="line"></span>material <span class="hljs-punctuation">{</span>
+</p></dd></dl></p><pre class="listing tilde"><code><span class="line"></span>material <span class="hljs-punctuation">{</span>
 <span class="line"></span>    parameters <span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span>
 <span class="line"></span>        <span class="hljs-punctuation">{</span>
 <span class="line"></span>           type <span class="hljs-punctuation">:</span> sampler2d<span class="hljs-punctuation">,</span>
@@ -1354,7 +1347,7 @@ non-shader data.
 <p>

 <dl><dt>Type</dt><dd><p>     array of <code>string</code>
-</p></dd><dt>Value</dt><dd><p>      Up to 5 strings, each must be a valid GLSL identifier.
+</p></dd><dt>Value</dt><dd><p>      Up to 4 strings, each must be a valid GLSL identifier.
 </p></dd><dt>Description</dt><dd><p>      Defines custom interpolants (or variables) that are output by the material's vertex shader.
      Each entry of the array defines the name of an  interpolant. The full name in the fragment
      shader is the name of the interpolant with the <code>variable_</code> prefix. For instance, if you
@@ -1367,11 +1360,7 @@ non-shader data.
      In this case the specified precision is used as-is in both fragment and vertex stages, in
      particular if <code>default</code> is specified the default precision is used is the fragment shader
      (<code>mediump</code>) and in the vertex shader (<code>highp</code>).
-</p></dd></dl><div class="admonition warning"><div class="admonition-title"> Interaction with required attributes</div>
-</p><p>
-    If the <code>color</code> attribute is specified in the <code>required</code> list, then only four variables can be used
-    instead of five.</div>
-</p><pre class="listing tilde"><code><span class="line"></span>material <span class="hljs-punctuation">{</span>
+</p></dd></dl></p><pre class="listing tilde"><code><span class="line"></span>material <span class="hljs-punctuation">{</span>
 <span class="line"></span>    name <span class="hljs-punctuation">:</span> Skybox<span class="hljs-punctuation">,</span>
 <span class="line"></span>    parameters <span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span>
 <span class="line"></span>        <span class="hljs-punctuation">{</span>
@@ -1,36 +0,0 @@
-# Using Instruments on macOS
-
-When running a binary under Instruments on macOS, you may run into the following issue when
-launching or attaching to an executable:
-
-```
-Failed to gain authorization
-Recovery Suggestion: Target binary needs to be debuggable and signed with 'get-task-allow'
-```
-
-This is a security precaution; the solution is to code sign the binary with the
-`com.apple.security.get-task-allow` entitlement.
-
-1. Create an `entitlements.plist` file with the following contents:
-
-```
-<?xml version="1.0" encoding="UTF-8"?>
-<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
-<plist version="1.0">
-<dict>
-    <key>com.apple.security.get-task-allow</key>
-    <true/>
-</dict>
-</plist>
-```
-
-2. Run the following command:
-
-```
-codesign -s - --entitlements entitlements.plist <binary>
-```
-
-Replace `<binary>` with the name of the binary, for example: `out/cmake-debug/samples/gltf_viewer`.
-
-Afterwards, you should be able to successfully launch and attach to the executable using
-Instruments.
@@ -265,13 +265,6 @@ set(MATERIAL_SRCS
        src/materials/vsmMipmap.mat
 )

-if (NOT FILAMENT_DISABLE_GTAO)
-    list(APPEND MATERIAL_SRCS
-        src/materials/ssao/gtao.mat
-        src/materials/ssao/gtaoBentNormals.mat
-    )
-endif()
-
 set(MATERIAL_FL0_SRCS
        src/materials/defaultMaterial.mat
        src/materials/skybox.mat
@@ -321,14 +314,12 @@ if (FILAMENT_FORCE_PROFILING_MODE)
    add_definitions(-DFILAMENT_FORCE_PROFILING_MODE)
 endif()

-if (FILAMENT_DISABLE_GTAO)
-    add_definitions(-DFILAMENT_DISABLE_GTAO)
-endif()
-
 # ==================================================================================================
 # Definitions
 # ==================================================================================================

+# "2" corresponds to SYSTRACE_TAG_FILEMENT (See: utils/Systrace.h)
+add_definitions(-DSYSTRACE_TAG=2)
 add_definitions(-DFILAMENT_DFG_LUT_SIZE=${DFG_LUT_SIZE})
 add_definitions(
    -DFILAMENT_PER_RENDER_PASS_ARENA_SIZE_IN_MB=${FILAMENT_PER_RENDER_PASS_ARENA_SIZE_IN_MB}
@@ -472,30 +463,6 @@ add_custom_command(
        APPEND
 )

-if (NOT FILAMENT_DISABLE_GTAO)
-    add_custom_command(
-            OUTPUT "${MATERIAL_DIR}/gtao.filamat"
-            DEPENDS src/materials/ssao/ssaoUtils.fs
-            DEPENDS src/materials/ssao/ssct.fs
-            DEPENDS src/materials/utils/depthUtils.fs
-            DEPENDS src/materials/utils/geometry.fs
-            DEPENDS src/materials/ssao/gtaoImpl.fs
-            DEPENDS src/materials/ssao/ssctImpl.fs
-            APPEND
-    )
-
-    add_custom_command(
-            OUTPUT "${MATERIAL_DIR}/gtaoBentNormals.filamat"
-            DEPENDS src/materials/ssao/ssaoUtils.fs
-            DEPENDS src/materials/ssao/ssct.fs
-            DEPENDS src/materials/utils/depthUtils.fs
-            DEPENDS src/materials/utils/geometry.fs
-            DEPENDS src/materials/ssao/gtaoImpl.fs
-            DEPENDS src/materials/ssao/ssctImpl.fs
-            APPEND
-    )
-endif()
-
 add_custom_command(
        OUTPUT "${MATERIAL_DIR}/bilateralBlur.filamat"
        DEPENDS src/materials/ssao/ssaoUtils.fs
@@ -601,10 +568,6 @@ target_link_libraries(${TARGET} PUBLIC filaflat)
 target_link_libraries(${TARGET} PUBLIC filabridge)
 target_link_libraries(${TARGET} PUBLIC ibl-lite)

-if (FILAMENT_USE_ABSEIL_LOGGING)
-    target_link_libraries(${TARGET} PUBLIC absl::log)
-endif()
-
 if (FILAMENT_ENABLE_FGVIEWER)
    target_link_libraries(${TARGET} PUBLIC fgviewer)
    add_definitions(-DFILAMENT_ENABLE_FGVIEWER=1)
@@ -92,7 +92,7 @@ Copy your platform's Makefile below into a `Makefile` inside the same directory.
 ### Linux

 ```make
-FILAMENT_LIBS=-lfilament -lbackend -lbluegl -lbluevk -lfilabridge -lfilaflat -lutils -lgeometry -lsmol-v -lvkshaders -libl -labseil
+FILAMENT_LIBS=-lfilament -lbackend -lbluegl -lbluevk -lfilabridge -lfilaflat -lutils -lgeometry -lsmol-v -lvkshaders -libl
 CC=clang++

 main: main.o
@@ -110,13 +110,12 @@ clean:
 ### macOS

 ```make
-FILAMENT_LIBS=-lfilament -lbackend -lbluegl -lbluevk -lfilabridge -lfilaflat -lutils -lgeometry -lsmol-v -lvkshaders -libl -labseil
+FILAMENT_LIBS=-lfilament -lbackend -lbluegl -lbluevk -lfilabridge -lfilaflat -lutils -lgeometry -lsmol-v -lvkshaders -libl
 FRAMEWORKS=-framework Cocoa -framework Metal -framework CoreVideo
 CC=clang++
-ARCH ?= $(shell uname -m)

 main: main.o
-	$(CC) -Llib/$(ARCH)/ main.o $(FILAMENT_LIBS) $(FRAMEWORKS) -o main
+	$(CC) -Llib/x86_64/ main.o $(FILAMENT_LIBS) $(FRAMEWORKS) -o main

 main.o: main.cpp
 	$(CC) -Iinclude/ -std=c++17 -c main.cpp
@@ -140,7 +139,7 @@ used to change the run-time library version.

 ```make
 FILAMENT_LIBS=filament.lib backend.lib bluegl.lib bluevk.lib filabridge.lib filaflat.lib \
-              utils.lib geometry.lib smol-v.lib ibl.lib vkshaders.lib abseil.lib
+              utils.lib geometry.lib smol-v.lib ibl.lib vkshaders.lib
 CC=cl.exe

 main.exe: main.obj
@@ -180,11 +180,8 @@ if (FILAMENT_SUPPORTS_VULKAN)
            src/vulkan/VulkanAsyncHandles.h
            src/vulkan/VulkanBlitter.cpp
            src/vulkan/VulkanBlitter.h
+            src/vulkan/VulkanBuffer.cpp
            src/vulkan/VulkanBuffer.h
-            src/vulkan/VulkanBufferCache.h
-            src/vulkan/VulkanBufferCache.cpp
-            src/vulkan/VulkanBufferProxy.h
-            src/vulkan/VulkanBufferProxy.cpp
            src/vulkan/VulkanCommands.cpp
            src/vulkan/VulkanCommands.h
            src/vulkan/VulkanConstants.h
@@ -257,44 +254,16 @@ if (FILAMENT_SUPPORTS_WEBGPU)
    list(APPEND SRCS
            include/backend/platforms/WebGPUPlatform.h
            src/webgpu/platform/WebGPUPlatform.cpp
-            src/webgpu/SpdMipmapGenerator/SpdMipmapGenerator.cpp
-            src/webgpu/WebGPUBufferBase.cpp
-            src/webgpu/WebGPUBufferBase.h
-            src/webgpu/WebGPUBufferObject.cpp
-            src/webgpu/WebGPUBufferObject.h
            src/webgpu/WebGPUConstants.h
-            src/webgpu/WebGPUDescriptorSet.cpp
-            src/webgpu/WebGPUDescriptorSet.h
-            src/webgpu/WebGPUDescriptorSetLayout.cpp
-            src/webgpu/WebGPUDescriptorSetLayout.h
            src/webgpu/WebGPUDriver.cpp
            src/webgpu/WebGPUDriver.h
-            src/webgpu/WebGPUFence.cpp
-            src/webgpu/WebGPUFence.h
-            src/webgpu/WebGPUIndexBuffer.cpp
-            src/webgpu/WebGPUIndexBuffer.h
-            src/webgpu/WebGPUMsaaTextureResolver.cpp
-            src/webgpu/WebGPUMsaaTextureResolver.h
-            src/webgpu/WebGPUPipelineCache.cpp
-            src/webgpu/WebGPUPipelineCache.h
-            src/webgpu/WebGPUPipelineLayoutCache.cpp
-            src/webgpu/WebGPUPipelineLayoutCache.h
-            src/webgpu/WebGPUProgram.cpp
-            src/webgpu/WebGPUProgram.h
-            src/webgpu/WebGPURenderPassMipmapGenerator.cpp
-            src/webgpu/WebGPURenderPassMipmapGenerator.h
-            src/webgpu/WebGPURenderPrimitive.h
-            src/webgpu/WebGPURenderTarget.cpp
-            src/webgpu/WebGPURenderTarget.h
-            src/webgpu/WebGPUStrings.h
+            src/webgpu/WebGPUHandles.cpp
+            src/webgpu/WebGPUHandles.h
+            src/webgpu/WebGPUPipelineCreation.cpp
+            src/webgpu/WebGPUPipelineCreation.h
            src/webgpu/WebGPUSwapChain.cpp
            src/webgpu/WebGPUSwapChain.h
-            src/webgpu/WebGPUTexture.cpp
-            src/webgpu/WebGPUTexture.h
-            src/webgpu/WebGPUVertexBuffer.cpp
-            src/webgpu/WebGPUVertexBuffer.h
-            src/webgpu/WebGPUVertexBufferInfo.cpp
-            src/webgpu/WebGPUVertexBufferInfo.h
+            src/webgpu/WGPUProgram.cpp
    )
    if (WIN32)
        list(APPEND SRCS src/webgpu/platform/WebGPUPlatformWindows.cpp)
@@ -321,6 +290,12 @@ if (ANDROID)
    list(APPEND SRCS src/BackendUtilsAndroid.cpp)
 endif()

+# ==================================================================================================
+# Definitions
+# ==================================================================================================
+# "2" corresponds to SYSTRACE_TAG_FILEMENT (See: utils/Systrace.h)
+add_definitions(-DSYSTRACE_TAG=2 )
+
 # ==================================================================================================
 # Includes & target definition
 # ==================================================================================================
@@ -412,10 +387,6 @@ endif()
 target_link_libraries(${TARGET} PUBLIC math)
 target_link_libraries(${TARGET} PUBLIC utils)

-if (FILAMENT_USE_ABSEIL_LOGGING)
-    target_link_libraries(${TARGET} PRIVATE absl::log)
-endif()
-
 # Android, iOS, and WebGL do not use bluegl.
 if(FILAMENT_SUPPORTS_OPENGL AND NOT IOS AND NOT ANDROID AND NOT WEBGL)
    target_link_libraries(${TARGET} PRIVATE bluegl)
@@ -511,20 +482,11 @@ if (FILAMENT_SUPPORTS_WEBGPU)
    target_compile_definitions(${TARGET} PRIVATE $<$<BOOL:${FILAMENT_WEBGPU_IMMEDIATE_ERROR_HANDLING}>:FILAMENT_WEBGPU_IMMEDIATE_ERROR_HANDLING>)
 endif()

-# ==================================================================================================
-# Linker flags
-# ==================================================================================================
-
 target_link_libraries(${TARGET} PRIVATE
+        ${OSMESA_LINKER_FLAGS}
        $<$<AND:$<PLATFORM_ID:Linux>,$<CONFIG:Release>>:${LINUX_LINKER_OPTIMIZATION_FLAGS}>
 )

-if (LINUX AND FILAMENT_SUPPORTS_WEBGPU)
-    # Unclear why this needs to be explicit while other linux libs do not, but it is necessary for
-    # WebGPU to build on linux.
-    target_link_libraries(${TARGET} PRIVATE -lxcb)
-endif()
-
 # ==================================================================================================
 # Installation
 # ==================================================================================================
@@ -20,15 +20,10 @@
 #define TNT_FILAMENT_BACKEND_BUFFERDESCRIPTOR_H

 #include <utils/compiler.h>
-
-#include <utility>
+#include <utils/ostream.h>

 #include <stddef.h>

-namespace utils::io {
-class ostream;
-} // namespace utils::io
-
 namespace filament::backend {

 class CallbackHandler;
@@ -94,8 +89,8 @@ public:
     * @param callback  A callback used to release the CPU buffer from this BufferDescriptor
     * @param user      An opaque user pointer passed to the callback function when it's called
     */
-    BufferDescriptor(void const* buffer, size_t const size,
-            Callback const callback = nullptr, void* user = nullptr) noexcept
+    BufferDescriptor(void const* buffer, size_t size,
+            Callback callback = nullptr, void* user = nullptr) noexcept
                : buffer(const_cast<void*>(buffer)), size(size), mCallback(callback), mUser(user) {
    }

@@ -103,12 +98,11 @@ public:
     * Creates a BufferDescriptor that references a CPU memory-buffer
     * @param buffer    Memory address of the CPU buffer to reference
     * @param size      Size of the CPU buffer in bytes
-     * @param handler   A custom handler for the callback
     * @param callback  A callback used to release the CPU buffer from this BufferDescriptor
     * @param user      An opaque user pointer passed to the callback function when it's called
     */
-    BufferDescriptor(void const* buffer, size_t const size,
-            CallbackHandler* handler, Callback const callback, void* user = nullptr) noexcept
+    BufferDescriptor(void const* buffer, size_t size,
+            CallbackHandler* handler, Callback callback, void* user = nullptr) noexcept
                : buffer(const_cast<void*>(buffer)), size(size),
                mCallback(callback), mUser(user), mHandler(handler) {
    }
@@ -122,9 +116,8 @@ public:
     *
     * @param buffer    Memory address of the CPU buffer to reference
     * @param size      Size of the CPU buffer in bytes
-     * @param data      A pointer to the data
     * @param handler   Handler to use to dispatch the callback, or nullptr for the default handler
-     * @return          A new BufferDescriptor
+     * @return          a new BufferDescriptor
     */
    template<typename T, void(T::*method)(void const*, size_t)>
    static BufferDescriptor make(void const* buffer, size_t size, T* data,
@@ -171,7 +164,7 @@ public:
     * @param callback  The new callback function
     * @param user      An opaque user pointer passed to the callbeck function when it's called
     */
-    void setCallback(Callback const callback, void* user = nullptr) noexcept {
+    void setCallback(Callback callback, void* user = nullptr) noexcept {
        this->mCallback = callback;
        this->mUser = user;
        this->mHandler = nullptr;
@@ -183,7 +176,7 @@ public:
     * @param callback  The new callback function
     * @param user      An opaque user pointer passed to the callbeck function when it's called
     */
-    void setCallback(CallbackHandler* handler, Callback const callback, void* user = nullptr) noexcept {
+    void setCallback(CallbackHandler* handler, Callback callback, void* user = nullptr) noexcept {
        mCallback = callback;
        mUser = user;
        mHandler = handler;
@@ -19,6 +19,8 @@

 #include <backend/DriverApiForward.h>

+#include <utils/ostream.h>
+
 #include <initializer_list>
 #include <memory>

@@ -26,10 +28,6 @@
 #include <stdint.h>


-namespace utils::io {
-class ostream;
-} // namespace utils::io
-
 namespace filament::backend {

 void* allocateFromCommandStream(DriverApi& driver, size_t size, size_t alignment) noexcept;
@@ -25,26 +25,22 @@
 #include <backend/PresentCallable.h>

 #include <utils/BitmaskEnum.h>
-#include <utils/CString.h>
 #include <utils/FixedCapacityVector.h>
 #include <utils/Invocable.h>
-#include <utils/StaticString.h>
+#include <utils/compiler.h>
 #include <utils/debug.h>
+#include <utils/ostream.h>
+#include <utils/StaticString.h>

 #include <math/vec4.h>

 #include <array>
 #include <type_traits>
 #include <variant>
-#include <string_view>

 #include <stddef.h>
 #include <stdint.h>

-namespace utils::io {
-class ostream;
-} // namespace utils::io
-
 /**
 * Types and enums used by filament's driver.
 *
@@ -163,7 +159,7 @@ enum class TimerQueryResult : int8_t {
    AVAILABLE = 1,  // result is available
 };

-constexpr std::string_view to_string(Backend const backend) noexcept {
+static constexpr const char* backendToString(Backend backend) {
    switch (backend) {
        case Backend::NOOP:
            return "Noop";
@@ -175,10 +171,9 @@ constexpr std::string_view to_string(Backend const backend) noexcept {
            return "Metal";
        case Backend::WEBGPU:
            return "WebGPU";
-        case Backend::DEFAULT:
-            return "Default";
+        default:
+            return "Unknown";
    }
-    return "Unknown";
 }

 /**
@@ -195,7 +190,7 @@ enum class ShaderLanguage {
    WGSL = 5,
 };

-constexpr const char* shaderLanguageToString(ShaderLanguage shaderLanguage) noexcept {
+static constexpr const char* shaderLanguageToString(ShaderLanguage shaderLanguage) {
    switch (shaderLanguage) {
        case ShaderLanguage::ESSL1:
            return "ESSL 1.0";
@@ -210,7 +205,6 @@ constexpr const char* shaderLanguageToString(ShaderLanguage shaderLanguage) noex
        case ShaderLanguage::WGSL:
            return "WGSL";
    }
-    return "UNKNOWN";
 }

 enum class ShaderStage : uint8_t {
@@ -228,7 +222,7 @@ enum class ShaderStageFlags : uint8_t {
    ALL_SHADER_STAGE_FLAGS = VERTEX | FRAGMENT | COMPUTE
 };

-constexpr bool hasShaderType(ShaderStageFlags flags, ShaderStage type) noexcept {
+static inline constexpr bool hasShaderType(ShaderStageFlags flags, ShaderStage type) noexcept {
    switch (type) {
        case ShaderStage::VERTEX:
            return bool(uint8_t(flags) & uint8_t(ShaderStageFlags::VERTEX));
@@ -239,247 +233,17 @@ constexpr bool hasShaderType(ShaderStageFlags flags, ShaderStage type) noexcept
    }
 }

-enum class TextureType : uint8_t {
-    FLOAT,
-    INT,
-    UINT,
-    DEPTH,
-    STENCIL,
-    DEPTH_STENCIL
+enum class DescriptorType : uint8_t {
+    UNIFORM_BUFFER,
+    SHADER_STORAGE_BUFFER,
+    SAMPLER,
+    INPUT_ATTACHMENT,
+    SAMPLER_EXTERNAL
 };

-constexpr std::string_view to_string(TextureType type) noexcept {
-    switch (type) {
-        case TextureType::FLOAT:            return "FLOAT";
-        case TextureType::INT:              return "INT";
-        case TextureType::UINT:             return "UINT";
-        case TextureType::DEPTH:            return "DEPTH";
-        case TextureType::STENCIL:          return "STENCIL";
-        case TextureType::DEPTH_STENCIL:    return "DEPTH_STENCIL";
-    }
-    return "UNKNOWN";
-}
-
- enum class DescriptorType : uint8_t {
-     SAMPLER_2D_FLOAT,
-     SAMPLER_2D_INT,
-     SAMPLER_2D_UINT,
-     SAMPLER_2D_DEPTH,
-
-     SAMPLER_2D_ARRAY_FLOAT,
-     SAMPLER_2D_ARRAY_INT,
-     SAMPLER_2D_ARRAY_UINT,
-     SAMPLER_2D_ARRAY_DEPTH,
-
-     SAMPLER_CUBE_FLOAT,
-     SAMPLER_CUBE_INT,
-     SAMPLER_CUBE_UINT,
-     SAMPLER_CUBE_DEPTH,
-
-     SAMPLER_CUBE_ARRAY_FLOAT,
-     SAMPLER_CUBE_ARRAY_INT,
-     SAMPLER_CUBE_ARRAY_UINT,
-     SAMPLER_CUBE_ARRAY_DEPTH,
-
-     SAMPLER_3D_FLOAT,
-     SAMPLER_3D_INT,
-     SAMPLER_3D_UINT,
-
-     SAMPLER_2D_MS_FLOAT,
-     SAMPLER_2D_MS_INT,
-     SAMPLER_2D_MS_UINT,
-
-     SAMPLER_2D_MS_ARRAY_FLOAT,
-     SAMPLER_2D_MS_ARRAY_INT,
-     SAMPLER_2D_MS_ARRAY_UINT,
-
-     SAMPLER_EXTERNAL,
-     UNIFORM_BUFFER,
-     SHADER_STORAGE_BUFFER,
-     INPUT_ATTACHMENT,
- };
-
-constexpr bool isDepthDescriptor(DescriptorType const type) noexcept {
-    switch (type) {
-        case DescriptorType::SAMPLER_2D_DEPTH:
-        case DescriptorType::SAMPLER_2D_ARRAY_DEPTH:
-        case DescriptorType::SAMPLER_CUBE_DEPTH:
-        case DescriptorType::SAMPLER_CUBE_ARRAY_DEPTH:
-            return true;
-        default: ;
-    }
-    return false;
-}
-
-constexpr bool isFloatDescriptor(DescriptorType const type) noexcept {
-    switch (type) {
-        case DescriptorType::SAMPLER_2D_FLOAT:
-        case DescriptorType::SAMPLER_2D_ARRAY_FLOAT:
-        case DescriptorType::SAMPLER_CUBE_FLOAT:
-        case DescriptorType::SAMPLER_CUBE_ARRAY_FLOAT:
-        case DescriptorType::SAMPLER_3D_FLOAT:
-        case DescriptorType::SAMPLER_2D_MS_FLOAT:
-        case DescriptorType::SAMPLER_2D_MS_ARRAY_FLOAT:
-            return true;
-        default: ;
-    }
-    return false;
-}
-
-constexpr bool isIntDescriptor(DescriptorType const type) noexcept {
-    switch (type) {
-        case DescriptorType::SAMPLER_2D_INT:
-        case DescriptorType::SAMPLER_2D_ARRAY_INT:
-        case DescriptorType::SAMPLER_CUBE_INT:
-        case DescriptorType::SAMPLER_CUBE_ARRAY_INT:
-        case DescriptorType::SAMPLER_3D_INT:
-        case DescriptorType::SAMPLER_2D_MS_INT:
-        case DescriptorType::SAMPLER_2D_MS_ARRAY_INT:
-            return true;
-        default: ;
-    }
-    return false;
-}
-
-constexpr bool isUnsignedIntDescriptor(DescriptorType const type) noexcept {
-    switch (type) {
-        case DescriptorType::SAMPLER_2D_UINT:
-        case DescriptorType::SAMPLER_2D_ARRAY_UINT:
-        case DescriptorType::SAMPLER_CUBE_UINT:
-        case DescriptorType::SAMPLER_CUBE_ARRAY_UINT:
-        case DescriptorType::SAMPLER_3D_UINT:
-        case DescriptorType::SAMPLER_2D_MS_UINT:
-        case DescriptorType::SAMPLER_2D_MS_ARRAY_UINT:
-            return true;
-        default: ;
-    }
-    return false;
-}
-
-constexpr bool is3dTypeDescriptor(DescriptorType const type) noexcept {
-    switch (type) {
-        case DescriptorType::SAMPLER_3D_FLOAT:
-        case DescriptorType::SAMPLER_3D_INT:
-        case DescriptorType::SAMPLER_3D_UINT:
-            return true;
-        default: ;
-    }
-    return false;
-}
-
-constexpr bool is2dTypeDescriptor(DescriptorType const type) noexcept {
-    switch (type) {
-        case DescriptorType::SAMPLER_2D_FLOAT:
-        case DescriptorType::SAMPLER_2D_INT:
-        case DescriptorType::SAMPLER_2D_UINT:
-        case DescriptorType::SAMPLER_2D_DEPTH:
-        case DescriptorType::SAMPLER_2D_MS_FLOAT:
-        case DescriptorType::SAMPLER_2D_MS_INT:
-        case DescriptorType::SAMPLER_2D_MS_UINT:
-            return true;
-        default: ;
-    }
-    return false;
-}
-
-constexpr bool is2dArrayTypeDescriptor(DescriptorType const type) noexcept {
-    switch (type) {
-        case DescriptorType::SAMPLER_2D_ARRAY_FLOAT:
-        case DescriptorType::SAMPLER_2D_ARRAY_INT:
-        case DescriptorType::SAMPLER_2D_ARRAY_UINT:
-        case DescriptorType::SAMPLER_2D_ARRAY_DEPTH:
-        case DescriptorType::SAMPLER_2D_MS_ARRAY_FLOAT:
-        case DescriptorType::SAMPLER_2D_MS_ARRAY_INT:
-        case DescriptorType::SAMPLER_2D_MS_ARRAY_UINT:
-            return true;
-        default: ;
-    }
-    return false;
-}
-
-constexpr bool isCubeTypeDescriptor(DescriptorType const type) noexcept {
-    switch (type) {
-        case DescriptorType::SAMPLER_CUBE_FLOAT:
-        case DescriptorType::SAMPLER_CUBE_INT:
-        case DescriptorType::SAMPLER_CUBE_UINT:
-        case DescriptorType::SAMPLER_CUBE_DEPTH:
-            return true;
-        default: ;
-    }
-    return false;
-}
-
-constexpr bool isCubeArrayTypeDescriptor(DescriptorType const type) noexcept {
-    switch (type) {
-        case DescriptorType::SAMPLER_CUBE_ARRAY_FLOAT:
-        case DescriptorType::SAMPLER_CUBE_ARRAY_INT:
-        case DescriptorType::SAMPLER_CUBE_ARRAY_UINT:
-        case DescriptorType::SAMPLER_CUBE_ARRAY_DEPTH:
-            return true;
-        default: ;
-    }
-    return false;
-}
-
-constexpr bool isMultiSampledTypeDescriptor(DescriptorType const type) noexcept {
-    switch (type) {
-        case DescriptorType::SAMPLER_2D_MS_FLOAT:
-        case DescriptorType::SAMPLER_2D_MS_INT:
-        case DescriptorType::SAMPLER_2D_MS_UINT:
-        case DescriptorType::SAMPLER_2D_MS_ARRAY_FLOAT:
-        case DescriptorType::SAMPLER_2D_MS_ARRAY_INT:
-        case DescriptorType::SAMPLER_2D_MS_ARRAY_UINT:
-            return true;
-        default: ;
-    }
-    return false;
-}
-
-constexpr std::string_view to_string(DescriptorType type) noexcept {
-    #define DESCRIPTOR_TYPE_CASE(TYPE)  case DescriptorType::TYPE: return #TYPE;
-    switch (type) {
-        DESCRIPTOR_TYPE_CASE(SAMPLER_2D_FLOAT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_2D_INT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_2D_UINT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_2D_DEPTH)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_2D_ARRAY_FLOAT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_2D_ARRAY_INT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_2D_ARRAY_UINT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_2D_ARRAY_DEPTH)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_CUBE_FLOAT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_CUBE_INT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_CUBE_UINT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_CUBE_DEPTH)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_CUBE_ARRAY_FLOAT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_CUBE_ARRAY_INT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_CUBE_ARRAY_UINT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_CUBE_ARRAY_DEPTH)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_3D_FLOAT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_3D_INT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_3D_UINT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_2D_MS_FLOAT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_2D_MS_INT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_2D_MS_UINT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_2D_MS_ARRAY_FLOAT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_2D_MS_ARRAY_INT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_2D_MS_ARRAY_UINT)
-        DESCRIPTOR_TYPE_CASE(SAMPLER_EXTERNAL)
-        DESCRIPTOR_TYPE_CASE(UNIFORM_BUFFER)
-        DESCRIPTOR_TYPE_CASE(SHADER_STORAGE_BUFFER)
-        DESCRIPTOR_TYPE_CASE(INPUT_ATTACHMENT)
-    }
-    return "UNKNOWN";
-    #undef DESCRIPTOR_TYPE_CASE
-}
-
 enum class DescriptorFlags : uint8_t {
    NONE = 0x00,
-
-    // Indicate a UNIFORM_BUFFER will have dynamic offsets.
-    DYNAMIC_OFFSET = 0x01,
-
-    // To indicate a texture/sampler type should be unfiltered.
-    UNFILTERABLE = 0x02,
+    DYNAMIC_OFFSET = 0x01
 };

 using descriptor_set_t = uint8_t;
@@ -487,25 +251,24 @@ using descriptor_set_t = uint8_t;
 using descriptor_binding_t = uint8_t;

 struct DescriptorSetLayoutBinding {
-    static bool isSampler(DescriptorType type) noexcept {
-        return int(type) <= int(DescriptorType::SAMPLER_EXTERNAL);
-    }
-    static bool isBuffer(DescriptorType type) noexcept {
-        return type == DescriptorType::UNIFORM_BUFFER ||
-               type == DescriptorType::SHADER_STORAGE_BUFFER;
-    }
    DescriptorType type;
    ShaderStageFlags stageFlags;
    descriptor_binding_t binding;
    DescriptorFlags flags = DescriptorFlags::NONE;
    uint16_t count = 0;

-    friend bool operator==(DescriptorSetLayoutBinding const& lhs,
+    //  TODO: uncomment when needed.  Note that this class is used as hash key.  We need to ensure
+    //  no uninitialized padding bytes.
+    //    uint8_t externalSamplerDataIndex = EXTERNAL_SAMPLER_DATA_INDEX_UNUSED;
+
+    friend inline bool operator==(DescriptorSetLayoutBinding const& lhs,
            DescriptorSetLayoutBinding const& rhs) noexcept {
        return lhs.type == rhs.type &&
               lhs.flags == rhs.flags &&
               lhs.count == rhs.count &&
               lhs.stageFlags == rhs.stageFlags;
+//               lhs.stageFlags == rhs.stageFlags &&
+//               lhs.externalSamplerDataIndex == rhs.externalSamplerDataIndex;
    }
 };

@@ -531,7 +294,7 @@ enum class TargetBufferFlags : uint32_t {
    ALL = COLOR_ALL | DEPTH | STENCIL       //!< Color, depth and stencil buffer selected.
 };

-constexpr TargetBufferFlags getTargetBufferFlagsAt(size_t index) noexcept {
+inline constexpr TargetBufferFlags getTargetBufferFlagsAt(size_t index) noexcept {
    if (index == 0u) return TargetBufferFlags::COLOR0;
    if (index == 1u) return TargetBufferFlags::COLOR1;
    if (index == 2u) return TargetBufferFlags::COLOR2;
@@ -688,24 +451,6 @@ enum class SamplerType : uint8_t {
    SAMPLER_CUBEMAP_ARRAY,  //!< Cube map array texture (feature level 2)
 };

-constexpr std::string_view to_string(SamplerType const type) noexcept {
-    switch (type) {
-        case SamplerType::SAMPLER_2D:
-            return "SAMPLER_2D";
-        case SamplerType::SAMPLER_2D_ARRAY:
-            return "SAMPLER_2D_ARRAY";
-        case SamplerType::SAMPLER_CUBEMAP:
-            return "SAMPLER_CUBEMAP";
-        case SamplerType::SAMPLER_EXTERNAL:
-            return "SAMPLER_EXTERNAL";
-        case SamplerType::SAMPLER_3D:
-            return "SAMPLER_3D";
-        case SamplerType::SAMPLER_CUBEMAP_ARRAY:
-            return "SAMPLER_CUBEMAP_ARRAY";
-    }
-    return "Unknown";
-}
-
 //! Subpass type
 enum class SubpassType : uint8_t {
    SUBPASS_INPUT
@@ -719,20 +464,6 @@ enum class SamplerFormat : uint8_t {
    SHADOW = 3      //!< shadow sampler (PCF)
 };

-constexpr std::string_view to_string(SamplerFormat const format) noexcept {
-    switch (format) {
-        case SamplerFormat::INT:
-            return "INT";
-        case SamplerFormat::UINT:
-            return "UINT";
-        case SamplerFormat::FLOAT:
-            return "FLOAT";
-        case SamplerFormat::SHADOW:
-            return "SHADOW";
-    }
-    return "Unknown";
-}
-
 /**
 * Supported element types
 */
@@ -772,15 +503,6 @@ enum class BufferObjectBinding : uint8_t {
    SHADER_STORAGE
 };

-constexpr std::string_view to_string(BufferObjectBinding type) noexcept {
-    switch (type) {
-        case BufferObjectBinding::VERTEX:           return "VERTEX";
-        case BufferObjectBinding::UNIFORM:          return "UNIFORM";
-        case BufferObjectBinding::SHADER_STORAGE:   return "SHADER_STORAGE";
-    }
-    return "UNKNOWN";
-}
-
 //! Face culling Mode
 enum class CullingMode : uint8_t {
    NONE,               //!< No culling, front and back faces are visible
@@ -1042,8 +764,6 @@ enum class TextureFormat : uint16_t {
    SRGB_ALPHA_BPTC_UNORM,  // BC7 sRGB
 };

-TextureType getTextureType(TextureFormat format) noexcept;
-
 //! Bitmask describing the intended Texture Usage
 enum class TextureUsage : uint16_t {
    NONE                = 0x0000,
@@ -1071,7 +791,7 @@ enum class TextureSwizzle : uint8_t {
 };

 //! returns whether this format a depth format
-constexpr bool isDepthFormat(TextureFormat format) noexcept {
+static constexpr bool isDepthFormat(TextureFormat format) noexcept {
    switch (format) {
        case TextureFormat::DEPTH32F:
        case TextureFormat::DEPTH24:
@@ -1084,7 +804,7 @@ constexpr bool isDepthFormat(TextureFormat format) noexcept {
    }
 }

-constexpr bool isStencilFormat(TextureFormat format) noexcept {
+static constexpr bool isStencilFormat(TextureFormat format) noexcept {
    switch (format) {
        case TextureFormat::STENCIL8:
        case TextureFormat::DEPTH24_STENCIL8:
@@ -1095,7 +815,7 @@ constexpr bool isStencilFormat(TextureFormat format) noexcept {
    }
 }

-constexpr bool isColorFormat(TextureFormat format) noexcept {
+inline constexpr bool isColorFormat(TextureFormat format) noexcept {
    switch (format) {
        // Standard color formats
        case TextureFormat::R8:
@@ -1122,7 +842,7 @@ constexpr bool isColorFormat(TextureFormat format) noexcept {
    return false;
 }

-constexpr bool isUnsignedIntFormat(TextureFormat format) {
+static constexpr bool isUnsignedIntFormat(TextureFormat format) {
    switch (format) {
        case TextureFormat::R8UI:
        case TextureFormat::R16UI:
@@ -1143,7 +863,7 @@ constexpr bool isUnsignedIntFormat(TextureFormat format) {
    }
 }

-constexpr bool isSignedIntFormat(TextureFormat format) {
+static constexpr bool isSignedIntFormat(TextureFormat format) {
    switch (format) {
        case TextureFormat::R8I:
        case TextureFormat::R16I:
@@ -1165,35 +885,35 @@ constexpr bool isSignedIntFormat(TextureFormat format) {
 }

 //! returns whether this format is a compressed format
-constexpr bool isCompressedFormat(TextureFormat format) noexcept {
+static constexpr bool isCompressedFormat(TextureFormat format) noexcept {
    return format >= TextureFormat::EAC_R11;
 }

 //! returns whether this format is an ETC2 compressed format
-constexpr bool isETC2Compression(TextureFormat format) noexcept {
+static constexpr bool isETC2Compression(TextureFormat format) noexcept {
    return format >= TextureFormat::EAC_R11 && format <= TextureFormat::ETC2_EAC_SRGBA8;
 }

 //! returns whether this format is an S3TC compressed format
-constexpr bool isS3TCCompression(TextureFormat format) noexcept {
+static constexpr bool isS3TCCompression(TextureFormat format) noexcept {
    return format >= TextureFormat::DXT1_RGB && format <= TextureFormat::DXT5_SRGBA;
 }

-constexpr bool isS3TCSRGBCompression(TextureFormat format) noexcept {
+static constexpr bool isS3TCSRGBCompression(TextureFormat format) noexcept {
    return format >= TextureFormat::DXT1_SRGB && format <= TextureFormat::DXT5_SRGBA;
 }

 //! returns whether this format is an RGTC compressed format
-constexpr bool isRGTCCompression(TextureFormat format) noexcept {
+static constexpr bool isRGTCCompression(TextureFormat format) noexcept {
    return format >= TextureFormat::RED_RGTC1 && format <= TextureFormat::SIGNED_RED_GREEN_RGTC2;
 }

 //! returns whether this format is an BPTC compressed format
-constexpr bool isBPTCCompression(TextureFormat format) noexcept {
+static constexpr bool isBPTCCompression(TextureFormat format) noexcept {
    return format >= TextureFormat::RGB_BPTC_SIGNED_FLOAT && format <= TextureFormat::SRGB_ALPHA_BPTC_UNORM;
 }

-constexpr bool isASTCCompression(TextureFormat format) noexcept {
+static constexpr bool isASTCCompression(TextureFormat format) noexcept {
    return format >= TextureFormat::RGBA_ASTC_4x4 && format <= TextureFormat::SRGB8_ALPHA8_ASTC_12x12;
 }

@@ -1253,6 +973,26 @@ enum class SamplerCompareFunc : uint8_t {
    N           //!< Never. The depth / stencil test always fails.
 };

+//! this API is copied from (and only applies to) the Vulkan spec.
+//! These specify YUV to RGB conversions.
+enum class SamplerYcbcrModelConversion : uint8_t {
+    RGB_IDENTITY = 0,
+    YCBCR_IDENTITY = 1,
+    YCBCR_709 = 2,
+    YCBCR_601 = 3,
+    YCBCR_2020 = 4,
+};
+
+enum class SamplerYcbcrRange : uint8_t {
+    ITU_FULL = 0,
+    ITU_NARROW = 1,
+};
+
+enum class ChromaLocation : uint8_t {
+    COSITED_EVEN = 0,
+    MIDPOINT = 1,
+};
+
 //! Sampler parameters
 struct SamplerParams {             // NOLINT
    SamplerMagFilter filterMag      : 1;    //!< magnification filter (NEAREST)
@@ -1294,23 +1034,19 @@ struct SamplerParams {             // NOLINT
            assert_invariant(lhs.padding2 == 0);
            auto* pLhs = reinterpret_cast<uint32_t const*>(reinterpret_cast<char const*>(&lhs));
            auto* pRhs = reinterpret_cast<uint32_t const*>(reinterpret_cast<char const*>(&rhs));
-            return *pLhs < *pRhs;
+            return *pLhs == *pRhs;
        }
    };

-    bool isFiltered() const noexcept {
-        return filterMag != SamplerMagFilter::NEAREST || filterMin != SamplerMinFilter::NEAREST;
-    }
-
 private:
-    friend bool operator == (SamplerParams lhs, SamplerParams rhs) noexcept {
-        return EqualTo{}(lhs, rhs);
+    friend inline bool operator == (SamplerParams lhs, SamplerParams rhs) noexcept {
+        return SamplerParams::EqualTo{}(lhs, rhs);
    }
-    friend bool operator != (SamplerParams lhs, SamplerParams rhs) noexcept {
-        return  !EqualTo{}(lhs, rhs);
+    friend inline bool operator != (SamplerParams lhs, SamplerParams rhs) noexcept {
+        return  !SamplerParams::EqualTo{}(lhs, rhs);
    }
-    friend bool operator < (SamplerParams lhs, SamplerParams rhs) noexcept {
-        return LessThan{}(lhs, rhs);
+    friend inline bool operator < (SamplerParams lhs, SamplerParams rhs) noexcept {
+        return SamplerParams::LessThan{}(lhs, rhs);
    }
 };

@@ -1321,9 +1057,94 @@ static_assert(sizeof(SamplerParams) == 4);
 static_assert(sizeof(SamplerParams) <= sizeof(uint64_t),
        "SamplerParams must be no more than 64 bits");

+//! Sampler parameters
+struct SamplerYcbcrConversion {// NOLINT
+    SamplerYcbcrModelConversion ycbcrModel : 4;
+    TextureSwizzle r : 4;
+    TextureSwizzle g : 4;
+    TextureSwizzle b : 4;
+    TextureSwizzle a : 4;
+    SamplerYcbcrRange ycbcrRange : 1;
+    ChromaLocation xChromaOffset : 1;
+    ChromaLocation yChromaOffset : 1;
+    SamplerMagFilter chromaFilter : 1;
+    uint8_t padding;
+
+    struct Hasher {
+        size_t operator()(const SamplerYcbcrConversion p) const noexcept {
+            // we don't use std::hash<> here, so we don't have to include <functional>
+            return *reinterpret_cast<uint32_t const*>(reinterpret_cast<char const*>(&p));
+        }
+    };
+
+    struct EqualTo {
+        bool operator()(SamplerYcbcrConversion lhs, SamplerYcbcrConversion rhs) const noexcept {
+            assert_invariant(lhs.padding == 0);
+            auto* pLhs = reinterpret_cast<uint32_t const*>(reinterpret_cast<char const*>(&lhs));
+            auto* pRhs = reinterpret_cast<uint32_t const*>(reinterpret_cast<char const*>(&rhs));
+            return *pLhs == *pRhs;
+        }
+    };
+
+    struct LessThan {
+        bool operator()(SamplerYcbcrConversion lhs, SamplerYcbcrConversion rhs) const noexcept {
+            assert_invariant(lhs.padding == 0);
+            auto* pLhs = reinterpret_cast<uint32_t const*>(reinterpret_cast<char const*>(&lhs));
+            auto* pRhs = reinterpret_cast<uint32_t const*>(reinterpret_cast<char const*>(&rhs));
+            return *pLhs < *pRhs;
+        }
+    };
+
+private:
+    friend inline bool operator == (SamplerYcbcrConversion lhs, SamplerYcbcrConversion rhs)
+            noexcept {
+        return SamplerYcbcrConversion::EqualTo{}(lhs, rhs);
+    }
+    friend inline bool operator != (SamplerYcbcrConversion lhs, SamplerYcbcrConversion rhs)
+            noexcept {
+        return  !SamplerYcbcrConversion::EqualTo{}(lhs, rhs);
+    }
+    friend inline bool operator < (SamplerYcbcrConversion lhs, SamplerYcbcrConversion rhs)
+            noexcept {
+        return SamplerYcbcrConversion::LessThan{}(lhs, rhs);
+    }
+};
+
+static_assert(sizeof(SamplerYcbcrConversion) == 4);
+
+static_assert(sizeof(SamplerYcbcrConversion) <= sizeof(uint64_t),
+        "SamplerYcbcrConversion must be no more than 64 bits");
+
+struct ExternalSamplerDatum {
+    ExternalSamplerDatum(SamplerYcbcrConversion ycbcr, SamplerParams spm, uint32_t extFmt)
+        : YcbcrConversion(ycbcr),
+          samplerParams(spm),
+          externalFormat(extFmt) {}
+    bool operator==(ExternalSamplerDatum const& rhs) const {
+        return (YcbcrConversion == rhs.YcbcrConversion && samplerParams == rhs.samplerParams &&
+                externalFormat == rhs.externalFormat);
+    }
+    struct EqualTo {
+        bool operator()(const ExternalSamplerDatum& lhs,
+                const ExternalSamplerDatum& rhs) const noexcept {
+            return (lhs.YcbcrConversion == rhs.YcbcrConversion &&
+                lhs.samplerParams == rhs.samplerParams &&
+                lhs.externalFormat == rhs.externalFormat);
+        }
+    };
+    SamplerYcbcrConversion YcbcrConversion;
+    SamplerParams samplerParams;
+    uint32_t externalFormat;
+};
+// No implicit padding allowed due to it being a hash key.
+static_assert(sizeof(ExternalSamplerDatum) == 12);
+
 struct DescriptorSetLayout {
    std::variant<utils::StaticString, utils::CString, std::monostate> label;
    utils::FixedCapacityVector<DescriptorSetLayoutBinding> bindings;
+
+//  TODO: uncomment when needed
+//    utils::FixedCapacityVector<ExternalSamplerDatum> externalSamplerData;
 };

 //! blending equation function
@@ -17,6 +17,9 @@
 #ifndef TNT_FILAMENT_BACKEND_HANDLE_H
 #define TNT_FILAMENT_BACKEND_HANDLE_H

+#if !defined(NDEBUG)
+#include <utils/ostream.h>
+#endif
 #include <utils/debug.h>

 #include <type_traits> // FIXME: STL headers are not allowed in public headers
@@ -24,10 +27,6 @@

 #include <stdint.h>

-namespace utils::io {
-class ostream;
-} // namespace utils::io
-
 namespace filament::backend {

 struct HwBufferObject;
@@ -20,14 +20,12 @@
 #include <backend/DriverEnums.h>
 #include <backend/Handle.h>

+#include <utils/ostream.h>
+
 #include <array>

 #include <stdint.h>

-namespace utils::io {
-class ostream;
-} // namespace utils::io
-
 namespace filament::backend {

 //! \privatesection
@@ -24,14 +24,11 @@

 #include <utils/compiler.h>
 #include <utils/debug.h>
+#include <utils/ostream.h>

 #include <stddef.h>
 #include <stdint.h>

-namespace utils::io {
-class ostream;
-} // namespace utils::io
-
 namespace filament::backend {

 /**
@@ -204,15 +201,23 @@ public:
                }, new T(std::forward<T>(functor))
        };
    }
+
+    // --------------------------------------------------------------------------------------------
+
    /**
-     * Computes the size in bytes for a pixel of given dimensions and format
+     * Computes the size in bytes needed to fit an image of given dimensions and format
     *
     * @param format    Format of the image pixels
     * @param type      Type of the image pixels
-     * @return The size of the specified pixel in bytes
+     * @param stride    Stride of a row in pixels
+     * @param height    Height of the image in rows
+     * @param alignment Alignment in bytes of pixel rows
+     * @return The buffer size needed to fit this image in bytes
     */
+    static constexpr size_t computeDataSize(PixelDataFormat format, PixelDataType type,
+            size_t stride, size_t height, size_t alignment) noexcept {
+        assert_invariant(alignment);

-    static constexpr size_t computePixelSize(PixelDataFormat format, PixelDataType type) noexcept {
        if (type == PixelDataType::COMPRESSED) {
            return 0;
        }
@@ -234,7 +239,7 @@ public:
            case PixelDataFormat::RGB_INTEGER:
                n = 3;
                break;
-            case PixelDataFormat::UNUSED:// shouldn't happen (used to be rgbm)
+            case PixelDataFormat::UNUSED: // shouldn't happen (used to be rgbm)
            case PixelDataFormat::RGBA:
            case PixelDataFormat::RGBA_INTEGER:
                n = 4;
@@ -243,7 +248,7 @@ public:

        size_t bpp = n;
        switch (type) {
-            case PixelDataType::COMPRESSED:// Impossible -- to squash the IDE warnings
+            case PixelDataType::COMPRESSED: // Impossible -- to squash the IDE warnings
            case PixelDataType::UBYTE:
            case PixelDataType::BYTE:
                // nothing to do
@@ -274,35 +279,16 @@ public:
                bpp = 2;
                break;
        }
-        return bpp;
-    }

-    // --------------------------------------------------------------------------------------------
-
-    /**
-     * Computes the size in bytes needed to fit an image of given dimensions and format
-     *
-     * @param format    Format of the image pixels
-     * @param type      Type of the image pixels
-     * @param stride    Stride of a row in pixels
-     * @param height    Height of the image in rows
-     * @param alignment Alignment in bytes of pixel rows
-     * @return The buffer size needed to fit this image in bytes
-     */
-    static constexpr size_t computeDataSize(PixelDataFormat format, PixelDataType type,
-            size_t stride, size_t height, size_t alignment) noexcept {
-        assert_invariant(alignment);
-
-        size_t bpp = computePixelSize(format, type);
        size_t const bpr = bpp * stride;
        size_t const bprAligned = (bpr + (alignment - 1)) & (~alignment + 1);
        return bprAligned * height;
    }

    //! left coordinate in pixels
-    uint32_t left = 0;
+    uint32_t left   = 0;
    //! top coordinate in pixels
-    uint32_t top = 0;
+    uint32_t top    = 0;
    union {
        struct {
            //! stride in pixels
@@ -107,36 +107,6 @@ public:
        MULTIVIEW,
    };

-    /**
-     * This controls the priority level for GPU work scheduling, which helps prioritize the
-     * submitted GPU work and enables preemption.
-     */
-    enum class GpuContextPriority : uint8_t {
-        /**
-         * Backend default GPU context priority (typically MEDIUM)
-         */
-        DEFAULT,
-        /**
-         * For non-interactive, deferrable workloads. This should not interfere with standard
-         * applications.
-         */
-        LOW,
-        /**
-         * The default priority level for standard applications.
-         */
-        MEDIUM,
-        /**
-         * For high-priority, latency-sensitive workloads that are more important than standard
-         * applications.
-         */
-        HIGH,
-        /**
-         * The highest priority, intended for system-critical, real-time applications where missing
-         * deadlines is unacceptable (e.g., VR/AR compositors or other system-critical tasks).
-         */
-        REALTIME,
-    };
-
    struct DriverConfig {
        /**
         * Size of handle arena in bytes. Setting to 0 indicates default value is to be used.
@@ -179,20 +149,6 @@ public:
         *      - PlatformEGLAndroid
         */
        bool assertNativeWindowIsValid = false;
-
-        /**
-         * The action to take if a Drawable cannot be acquired. If true, the
-         * frame is aborted instead of panic. This is only supported for:
-         *      - PlatformMetal
-         */
-        bool metalDisablePanicOnDrawableFailure = false;
-
-        /**
-         * GPU context priority level. Controls GPU work scheduling and preemption.
-         * This is only supported for:
-         *      - PlatformEGL
-         */
-        GpuContextPriority gpuContextPriority = GpuContextPriority::DEFAULT;
    };

    Platform() noexcept;
@@ -20,10 +20,12 @@
 #include <utils/CString.h>
 #include <utils/FixedCapacityVector.h>
 #include <utils/Invocable.h>
+#include <utils/ostream.h>

 #include <backend/DriverEnums.h>

 #include <array>
+#include <unordered_map>
 #include <tuple>
 #include <utility>
 #include <variant>
@@ -31,10 +33,6 @@
 #include <stddef.h>
 #include <stdint.h>

-namespace utils::io {
-class ostream;
-} // namespace utils::io
-
 namespace filament::backend {

 class Program {
@@ -19,26 +19,22 @@

 #include <backend/Handle.h>

-#include <utility>
+#include <utils/ostream.h>

 #include <stddef.h>
 #include <stdint.h>

-namespace utils::io {
-class ostream;
-} // namespace utils::io
-
 namespace filament::backend {

 //! \privatesection

 struct TargetBufferInfo {
    // note: the parameters of this constructor are not in the order of this structure's fields
-    TargetBufferInfo(Handle<HwTexture> handle, uint8_t const level, uint16_t const layer) noexcept
-            : handle(std::move(handle)), level(level), layer(layer) {
+    TargetBufferInfo(Handle<HwTexture> handle, uint8_t level, uint16_t layer) noexcept
+            : handle(handle), level(level), layer(layer) {
    }

-    TargetBufferInfo(Handle<HwTexture> handle, uint8_t const level) noexcept
+    TargetBufferInfo(Handle<HwTexture> handle, uint8_t level) noexcept
            : handle(handle), level(level) {
    }

@@ -74,11 +70,11 @@ private:
    TargetBufferInfo mInfos[MAX_SUPPORTED_RENDER_TARGET_COUNT];

 public:
-    TargetBufferInfo const& operator[](size_t const i) const noexcept {
+    TargetBufferInfo const& operator[](size_t i) const noexcept {
        return mInfos[i];
    }

-    TargetBufferInfo& operator[](size_t const i) noexcept {
+    TargetBufferInfo& operator[](size_t i) noexcept {
        return mInfos[i];
    }

@@ -199,7 +199,7 @@ public:
     */
    virtual bool makeCurrent(ContextType type,
            SwapChain* UTILS_NONNULL drawSwapChain,
-            SwapChain* UTILS_NONNULL readSwapChain) = 0;
+            SwapChain* UTILS_NONNULL readSwapChain) noexcept = 0;

    /**
     * Called by the driver to make the OpenGL context active on the calling thread and bind
@@ -219,7 +219,7 @@ public:
            SwapChain* UTILS_NONNULL drawSwapChain,
            SwapChain* UTILS_NONNULL readSwapChain,
            utils::Invocable<void()> preContextChange,
-            utils::Invocable<void(size_t index)> postContextChange);
+            utils::Invocable<void(size_t index)> postContextChange) noexcept;

    /**
     * Called by the backend just before calling commit()
@@ -58,7 +58,7 @@ protected:
    SwapChain* createSwapChain(void* nativewindow, uint64_t flags) noexcept override;
    SwapChain* createSwapChain(uint32_t width, uint32_t height, uint64_t flags) noexcept override;
    void destroySwapChain(SwapChain* swapChain) noexcept override;
-    bool makeCurrent(ContextType type, SwapChain* drawSwapChain, SwapChain* readSwapChain) override;
+    bool makeCurrent(ContextType type, SwapChain* drawSwapChain, SwapChain* readSwapChain) noexcept override;
    void commit(SwapChain* swapChain) noexcept override;
    ExternalTexture* createExternalImageTexture() noexcept override;
    void destroyExternalImageTexture(ExternalTexture* texture) noexcept override;
@@ -55,7 +55,7 @@ public:
    SwapChain* createSwapChain(void* nativewindow, uint64_t flags) noexcept override;
    SwapChain* createSwapChain(uint32_t width, uint32_t height, uint64_t flags) noexcept override;
    void destroySwapChain(SwapChain* swapChain) noexcept override;
-    bool makeCurrent(ContextType type, SwapChain* drawSwapChain, SwapChain* readSwapChain) override;
+    bool makeCurrent(ContextType type, SwapChain* drawSwapChain, SwapChain* readSwapChain) noexcept override;
    void commit(SwapChain* swapChain) noexcept override;

    ExternalTexture* createExternalImageTexture() noexcept override;
@@ -109,11 +109,11 @@ protected:

    bool makeCurrent(ContextType type,
            SwapChain* drawSwapChain,
-            SwapChain* readSwapChain) override;
+            SwapChain* readSwapChain) noexcept override;

    void makeCurrent(SwapChain* drawSwapChain, SwapChain* readSwapChain,
            utils::Invocable<void()> preContextChange,
-            utils::Invocable<void(size_t index)> postContextChange) override;
+            utils::Invocable<void(size_t index)> postContextChange) noexcept override;

    void commit(SwapChain* swapChain) noexcept override;

@@ -128,7 +128,7 @@ protected:
    bool setExternalImage(ExternalImageHandleRef externalImage, ExternalTexture* texture) noexcept override;

    /**
-     * Logs glGetError() to LOG(ERROR)
+     * Logs glGetError() to slog.e
     * @param name a string giving some context on the error. Typically __func__.
     */
    static void logEglError(const char* name) noexcept;
@@ -148,12 +148,12 @@ protected:
    EGLContext getContextForType(ContextType type) const noexcept;

    // makes the draw and read surface current without changing the current context
-    EGLBoolean makeCurrent(EGLSurface drawSurface, EGLSurface readSurface) {
+    EGLBoolean makeCurrent(EGLSurface drawSurface, EGLSurface readSurface) noexcept {
        return egl.makeCurrent(drawSurface, readSurface);
    }

    // makes context current and set draw and read surfaces to EGL_NO_SURFACE
-    EGLBoolean makeCurrent(EGLContext context) {
+    EGLBoolean makeCurrent(EGLContext context) noexcept {
        return egl.makeCurrent(context, mEGLDummySurface, mEGLDummySurface);
    }

@@ -211,9 +211,9 @@ private:
    public:
        explicit EGL(EGLDisplay& dpy) : mEGLDisplay(dpy) {}
        EGLBoolean makeCurrent(EGLContext context,
-                EGLSurface drawSurface, EGLSurface readSurface);
+                EGLSurface drawSurface, EGLSurface readSurface) noexcept;

-        EGLBoolean makeCurrent(EGLSurface drawSurface, EGLSurface readSurface) {
+        EGLBoolean makeCurrent(EGLSurface drawSurface, EGLSurface readSurface) noexcept {
            return makeCurrent(mCurrentContext, drawSurface, readSurface);
        }
    } egl{ mEGLDisplay };
@@ -127,7 +127,7 @@ protected:
 protected:
    bool makeCurrent(ContextType type,
            SwapChain* drawSwapChain,
-            SwapChain* readSwapChain) override;
+            SwapChain* readSwapChain) noexcept override;

 private:
    struct InitializeJvmForPerformanceManagerIfNeeded {
@@ -51,7 +51,7 @@ protected:
    SwapChain* createSwapChain(void* nativewindow, uint64_t flags) noexcept override;
    SwapChain* createSwapChain(uint32_t width, uint32_t height, uint64_t flags) noexcept override;
    void destroySwapChain(SwapChain* swapChain) noexcept override;
-    bool makeCurrent(ContextType type, SwapChain* drawSwapChain, SwapChain* readSwapChain) override;
+    bool makeCurrent(ContextType type, SwapChain* drawSwapChain, SwapChain* readSwapChain) noexcept override;
    void commit(SwapChain* swapChain) noexcept override;

 private:
@@ -39,40 +39,18 @@ public:
    Driver* createDriver(void* sharedContext, const Platform::DriverConfig& driverConfig) noexcept override;
    int getOSVersion() const noexcept override { return 0; }

-    /**
-     * Optionally initializes the Metal platform by acquiring resources necessary for rendering.
-     *
-     * This method attempts to acquire a Metal device and command queue, returning true if both are
-     * successfully obtained, or false otherwise. Typically, these objects are acquired when
-     * the Metal backend is initialized. This method allows clients to check for their availability
-     * earlier.
-     *
-     * Calling initialize() is optional and safe to do so multiple times. After initialize() returns
-     * true, subsequent calls will continue to return true but have no effect.
-     *
-     * initialize() must be called from the main thread.
-     *
-     * @returns true if the device and command queue have been successfully obtained; false
-     * otherwise.
-     */
-    bool initialize() noexcept;
-
    /**
     * Obtain the preferred Metal device object for the backend to use.
     *
     * On desktop platforms, there may be multiple GPUs suitable for rendering, and this method is
     * free to decide which one to use. On mobile systems with a single GPU, implementations should
     * simply return the result of MTLCreateSystemDefaultDevice();
-     *
-     * createDevice is called by the Metal backend from the backend thread.
     */
    virtual void createDevice(MetalDevice& outDevice) noexcept;

    /**
     * Create a command submission queue on the Metal device object.
     *
-     * createCommandQueue is called by the Metal backend from the backend thread.
-     *
     * @param device The device which was returned from createDevice()
     */
    virtual void createCommandQueue(
@@ -82,8 +60,6 @@ public:
     * Obtain a MTLCommandBuffer enqueued on this Platform's MTLCommandQueue. The command buffer is
     * guaranteed to execute before all subsequent command buffers created either by Filament, or
     * further calls to this method.
-     *
-     * createAndEnqueueCommandBuffer must be called from the main thread.
     */
    void createAndEnqueueCommandBuffer(MetalCommandBuffer& outCommandBuffer) noexcept;

@@ -92,8 +68,6 @@ public:
     *
     * Each frame rendered requires a CAMetalDrawable texture, which is presented on-screen at the
     * completion of each frame. These are limited and provided round-robin style by the system.
-     *
-     * setDrawableFailureBehavior must be called from the main thread.
     */
    enum class DrawableFailureBehavior : uint8_t {
        /**
@@ -56,7 +56,7 @@ protected:
    SwapChain* createSwapChain(uint32_t width, uint32_t height, uint64_t flags) noexcept override;
    void destroySwapChain(SwapChain* swapChain) noexcept override;
    bool makeCurrent(ContextType type, SwapChain* drawSwapChain,
-            SwapChain* readSwapChain) override;
+            SwapChain* readSwapChain) noexcept override;
    void commit(SwapChain* swapChain) noexcept override;

 private:
@@ -53,7 +53,7 @@ protected:
    SwapChain* createSwapChain(void* nativewindow, uint64_t flags) noexcept override;
    SwapChain* createSwapChain(uint32_t width, uint32_t height, uint64_t flags) noexcept override;
    void destroySwapChain(SwapChain* swapChain) noexcept override;
-    bool makeCurrent(ContextType type, SwapChain* drawSwapChain, SwapChain* readSwapChain) override;
+    bool makeCurrent(ContextType type, SwapChain* drawSwapChain, SwapChain* readSwapChain) noexcept override;
    void commit(SwapChain* swapChain) noexcept override;

 protected:
@@ -46,7 +46,7 @@ protected:
    SwapChain* createSwapChain(void* nativewindow, uint64_t flags) noexcept override;
    SwapChain* createSwapChain(uint32_t width, uint32_t height, uint64_t flags) noexcept override;
    void destroySwapChain(SwapChain* swapChain) noexcept override;
-    bool makeCurrent(ContextType type, SwapChain* drawSwapChain, SwapChain* readSwapChain) override;
+    bool makeCurrent(ContextType type, SwapChain* drawSwapChain, SwapChain* readSwapChain) noexcept override;
    void commit(SwapChain* swapChain) noexcept override;
 };

@@ -27,11 +27,8 @@
 #include <utils/Hash.h>
 #include <utils/PrivateImplementation.h>

-#include <cstddef>
-#include <functional>
 #include <tuple>
 #include <unordered_set>
-#include <string>

 #include <stddef.h>
 #include <stdint.h>
@@ -22,7 +22,6 @@
 #include <webgpu/webgpu_cpp.h>

 #include <cstdint>
-#include <vector>

 namespace filament::backend {

@@ -57,10 +56,6 @@ protected:
            const Platform::DriverConfig& driverConfig) noexcept override;

 private:
-    // returns adapter request option variations applicable for the particular
-    // platform
-    [[nodiscard]] static std::vector<wgpu::RequestAdapterOptions> getAdapterOptions();
-
    // we may consider having the driver own this in the future
    wgpu::Instance mInstance;
 };
@@ -72,7 +72,7 @@ public:
    Range getBuffer() noexcept;

 private:
-    void* alloc(size_t size);
+    void* alloc(size_t size) noexcept;
    void dealloc() noexcept;

    // pointer to the beginning of the circular buffer (constant)
@@ -76,7 +76,7 @@ public:

    // all commands buffers (Slices) written to this point are returned by waitForCommand(). This
    // call blocks until the CircularBuffer has at least mRequiredSize bytes available.
-    void flush();
+    void flush() noexcept;

    // returns from waitForCommands() immediately.
    void requestExit();
@@ -39,7 +39,7 @@
 #define FILAMENT_DEBUG_COMMANDS_NONE         0x0
 // Command debugging enabled. No logging by default.
 #define FILAMENT_DEBUG_COMMANDS_ENABLE       0x1
-// Command debugging enabled. Every command logged to DLOG(INFO)
+// Command debugging enabled. Every command logged to slog.d
 #define FILAMENT_DEBUG_COMMANDS_LOG          0x2
 // Command debugging enabled. Every command logged to systrace
 #define FILAMENT_DEBUG_COMMANDS_SYSTRACE     0x4
@@ -116,7 +116,7 @@ public:
     * Destroys the object D at Handle<B> and construct a new D in its place
     * e.g.:
     *  Handle<ConcreteTexture> h = allocateAndConstruct(w, h);
-     *  ConcreteTexture* p = destroyAndConstruct(h, w, h);
+     *  ConcreteTexture* p = reconstruct(h, w, h);
     */
    template<typename D, typename B, typename ... ARGS>
    std::enable_if_t<std::is_base_of_v<B, D>, D>*
@@ -27,13 +27,13 @@ namespace filament {
 class VirtualMachineEnv {
 public:
    // must be called before VirtualMachineEnv::get() from a thread that is attached to the JavaVM
-    static jint JNI_OnLoad(JavaVM* vm);
+    static jint JNI_OnLoad(JavaVM* vm) noexcept;

    // must be called on backend thread
    static VirtualMachineEnv& get() noexcept;

    // can be called from any thread that already has a JniEnv
-    static JNIEnv* getThreadEnvironment();
+    static JNIEnv* getThreadEnvironment() noexcept;

    // must be called from the backend thread
    JNIEnv* getEnvironment() noexcept {
@@ -49,7 +49,7 @@ public:
 private:
    explicit VirtualMachineEnv(JavaVM* vm) noexcept;
    ~VirtualMachineEnv() noexcept;
-    JNIEnv* getEnvironmentSlow();
+    JNIEnv* getEnvironmentSlow() noexcept;

    static utils::Mutex sLock;
    static JavaVM* sVirtualMachine;
@@ -18,8 +18,6 @@

 #include "DataReshaper.h"

-#include <backend/DriverEnums.h>
-
 #include <utils/CString.h>

 #include <string_view>
@@ -225,143 +223,6 @@ size_t getFormatSize(TextureFormat format) noexcept {
    }
 }

-TextureType getTextureType(TextureFormat const format) noexcept {
-    switch (format) {
-        case TextureFormat::UNUSED:
-            // should not happen
-            return TextureType::FLOAT;
-
-        case TextureFormat::R8:
-        case TextureFormat::R16F:
-        case TextureFormat::RG8:
-        case TextureFormat::RGB565:
-        case TextureFormat::RGB5_A1:
-        case TextureFormat::RGBA4:
-        case TextureFormat::R32F:
-        case TextureFormat::RGB8:
-        case TextureFormat::SRGB8:
-        case TextureFormat::RG16F:
-        case TextureFormat::R11F_G11F_B10F:
-        case TextureFormat::RGB9_E5:
-        case TextureFormat::RGBA8:
-        case TextureFormat::SRGB8_A8:
-        case TextureFormat::RGB10_A2:
-        case TextureFormat::RGB16F:
-        case TextureFormat::RG32F:
-        case TextureFormat::RGBA16F:
-        case TextureFormat::RGB32F:
-        case TextureFormat::RGBA32F:
-            return TextureType::FLOAT;
-
-        case TextureFormat::R8_SNORM:
-        case TextureFormat::RG8_SNORM:
-        case TextureFormat::RGB8_SNORM:
-        case TextureFormat::RGBA8_SNORM:
-            // SNORM are treated as float
-            return TextureType::FLOAT;
-
-        case TextureFormat::R8UI:
-        case TextureFormat::R16UI:
-        case TextureFormat::RG8UI:
-        case TextureFormat::RGB8UI:
-        case TextureFormat::R32UI:
-        case TextureFormat::RG16UI:
-        case TextureFormat::RGBA8UI:
-        case TextureFormat::RGB16UI:
-        case TextureFormat::RG32UI:
-        case TextureFormat::RGBA16UI:
-        case TextureFormat::RGB32UI:
-        case TextureFormat::RGBA32UI:
-            return TextureType::UINT;
-
-        case TextureFormat::R8I:
-        case TextureFormat::R16I:
-        case TextureFormat::RG8I:
-        case TextureFormat::RGB8I:
-        case TextureFormat::R32I:
-        case TextureFormat::RG16I:
-        case TextureFormat::RGBA8I:
-        case TextureFormat::RGB16I:
-        case TextureFormat::RG32I:
-        case TextureFormat::RGBA16I:
-        case TextureFormat::RGB32I:
-        case TextureFormat::RGBA32I:
-            return TextureType::INT;
-
-        case TextureFormat::DEPTH16:
-        case TextureFormat::DEPTH24:
-        case TextureFormat::DEPTH32F:
-            return TextureType::DEPTH;
-
-        case TextureFormat::STENCIL8:
-            return TextureType::STENCIL;
-
-        case TextureFormat::DEPTH24_STENCIL8:
-        case TextureFormat::DEPTH32F_STENCIL8:
-            return TextureType::DEPTH_STENCIL;
-
-        // Compressed formats ---------------------------------------------------------------------
-
-        case TextureFormat::EAC_RG11:
-        case TextureFormat::EAC_RG11_SIGNED:
-        case TextureFormat::ETC2_EAC_RGBA8:
-        case TextureFormat::ETC2_EAC_SRGBA8:
-        case TextureFormat::EAC_R11:
-        case TextureFormat::EAC_R11_SIGNED:
-        case TextureFormat::ETC2_RGB8:
-        case TextureFormat::ETC2_SRGB8:
-        case TextureFormat::ETC2_RGB8_A1:
-        case TextureFormat::ETC2_SRGB8_A1:
-        case TextureFormat::DXT1_RGB:
-        case TextureFormat::DXT1_RGBA:
-        case TextureFormat::DXT1_SRGB:
-        case TextureFormat::DXT1_SRGBA:
-        case TextureFormat::DXT3_RGBA:
-        case TextureFormat::DXT3_SRGBA:
-        case TextureFormat::DXT5_RGBA:
-        case TextureFormat::DXT5_SRGBA:
-        case TextureFormat::RED_RGTC1:
-        case TextureFormat::SIGNED_RED_RGTC1:
-        case TextureFormat::RED_GREEN_RGTC2:
-        case TextureFormat::SIGNED_RED_GREEN_RGTC2:
-        case TextureFormat::RGB_BPTC_SIGNED_FLOAT:
-        case TextureFormat::RGB_BPTC_UNSIGNED_FLOAT:
-        case TextureFormat::RGBA_BPTC_UNORM:
-        case TextureFormat::SRGB_ALPHA_BPTC_UNORM:
-        case TextureFormat::RGBA_ASTC_4x4:
-        case TextureFormat::RGBA_ASTC_5x4:
-        case TextureFormat::RGBA_ASTC_5x5:
-        case TextureFormat::RGBA_ASTC_6x5:
-        case TextureFormat::RGBA_ASTC_6x6:
-        case TextureFormat::RGBA_ASTC_8x5:
-        case TextureFormat::RGBA_ASTC_8x6:
-        case TextureFormat::RGBA_ASTC_8x8:
-        case TextureFormat::RGBA_ASTC_10x5:
-        case TextureFormat::RGBA_ASTC_10x6:
-        case TextureFormat::RGBA_ASTC_10x8:
-        case TextureFormat::RGBA_ASTC_10x10:
-        case TextureFormat::RGBA_ASTC_12x10:
-        case TextureFormat::RGBA_ASTC_12x12:
-        case TextureFormat::SRGB8_ALPHA8_ASTC_4x4:
-        case TextureFormat::SRGB8_ALPHA8_ASTC_5x4:
-        case TextureFormat::SRGB8_ALPHA8_ASTC_5x5:
-        case TextureFormat::SRGB8_ALPHA8_ASTC_6x5:
-        case TextureFormat::SRGB8_ALPHA8_ASTC_6x6:
-        case TextureFormat::SRGB8_ALPHA8_ASTC_8x5:
-        case TextureFormat::SRGB8_ALPHA8_ASTC_8x6:
-        case TextureFormat::SRGB8_ALPHA8_ASTC_8x8:
-        case TextureFormat::SRGB8_ALPHA8_ASTC_10x5:
-        case TextureFormat::SRGB8_ALPHA8_ASTC_10x6:
-        case TextureFormat::SRGB8_ALPHA8_ASTC_10x8:
-        case TextureFormat::SRGB8_ALPHA8_ASTC_10x10:
-        case TextureFormat::SRGB8_ALPHA8_ASTC_12x10:
-        case TextureFormat::SRGB8_ALPHA8_ASTC_12x12:
-            return TextureType::FLOAT;
-    }
-
-    return TextureType::FLOAT;
-}
-
 size_t getFormatComponentCount(TextureFormat format) noexcept {
    switch (format) {
        case TextureFormat::R8:
@@ -16,7 +16,7 @@

 #include "private/backend/CircularBuffer.h"

-#include <utils/Logger.h>
+#include <utils/Log.h>
 #include <utils/Panic.h>
 #include <utils/architecture.h>
 #include <utils/ashmem.h>
@@ -65,7 +65,7 @@ CircularBuffer::~CircularBuffer() noexcept {
 // to each others and a special case in circularize()

 UTILS_NOINLINE
-void* CircularBuffer::alloc(size_t size) {
+void* CircularBuffer::alloc(size_t size) noexcept {
 #if HAS_MMAP
    void* data = nullptr;
    void* vaddr = MAP_FAILED;
@@ -127,7 +127,7 @@ void* CircularBuffer::alloc(size_t size) {
                "couldn't allocate " << (size * 2 / 1024) <<
                " KiB of virtual address space for the command buffer";

-        LOG(WARNING) << "Using 'soft' CircularBuffer (" << (size * 2 / 1024) << " KiB)";
+        slog.w << "Using 'soft' CircularBuffer (" << (size * 2 / 1024) << " KiB)" << io::endl;

        // guard page at the end
        void* guard = (void*)(uintptr_t(data) + size * 2);
@@ -18,14 +18,13 @@
 #include "private/backend/CircularBuffer.h"
 #include "private/backend/CommandStream.h"

-#include <private/utils/Tracing.h>
-
-#include <utils/Logger.h>
-#include <utils/Mutex.h>
-#include <utils/Panic.h>
 #include <utils/compiler.h>
-#include <utils/debug.h>
+#include <utils/Log.h>
+#include <utils/Mutex.h>
 #include <utils/ostream.h>
+#include <utils/Panic.h>
+#include <utils/Systrace.h>
+#include <utils/debug.h>

 #include <algorithm>
 #include <mutex>
@@ -53,18 +52,18 @@ CommandBufferQueue::~CommandBufferQueue() {
 }

 void CommandBufferQueue::requestExit() {
-    std::lock_guard const lock(mLock);
+    std::lock_guard<utils::Mutex> const lock(mLock);
    mExitRequested = EXIT_REQUESTED;
    mCondition.notify_one();
 }

 bool CommandBufferQueue::isPaused() const noexcept {
-    std::lock_guard const lock(mLock);
+    std::lock_guard<utils::Mutex> const lock(mLock);
    return mPaused;
 }

 void CommandBufferQueue::setPaused(bool paused) {
-    std::lock_guard const lock(mLock);
+    std::lock_guard<utils::Mutex> const lock(mLock);
    if (paused) {
        mPaused = true;
    } else {
@@ -74,13 +73,13 @@ void CommandBufferQueue::setPaused(bool paused) {
 }

 bool CommandBufferQueue::isExitRequested() const {
-    std::lock_guard const lock(mLock);
-    return bool(mExitRequested);
+    std::lock_guard<utils::Mutex> const lock(mLock);
+    return (bool)mExitRequested;
 }


-void CommandBufferQueue::flush() {
-    FILAMENT_TRACING_CALL(FILAMENT_TRACING_CATEGORY_FILAMENT);
+void CommandBufferQueue::flush() noexcept {
+    SYSTRACE_CALL();

    CircularBuffer& circularBuffer = mCircularBuffer;
    if (circularBuffer.empty()) {
@@ -103,7 +102,7 @@ void CommandBufferQueue::flush() {
            static_cast<char const*>(begin), static_cast<char const*>(end));


-    std::unique_lock lock(mLock);
+    std::unique_lock<utils::Mutex> lock(mLock);

    // circular buffer is too small, we corrupted the stream
    FILAMENT_CHECK_POSTCONDITION(used <= mFreeSpace) <<
@@ -121,15 +120,16 @@ void CommandBufferQueue::flush() {

 #ifndef NDEBUG
        size_t const totalUsed = circularBuffer.size() - mFreeSpace;
-        DLOG(INFO) << "CommandStream used too much space (will block): "
-                   << "needed space " << requiredSize << " out of " << mFreeSpace
-                   << ", totalUsed=" << totalUsed << ", current=" << used
-                   << ", queue size=" << mCommandBuffersToExecute.size() << " buffers";
+        slog.d << "CommandStream used too much space (will block): "
+                << "needed space " << requiredSize << " out of " << mFreeSpace
+                << ", totalUsed=" << totalUsed << ", current=" << used
+                << ", queue size=" << mCommandBuffersToExecute.size() << " buffers"
+                << io::endl;

        mHighWatermark = std::max(mHighWatermark, totalUsed);
 #endif

-        FILAMENT_TRACING_NAME(FILAMENT_TRACING_CATEGORY_FILAMENT, "waiting: CircularBuffer::flush()");
+        SYSTRACE_NAME("waiting: CircularBuffer::flush()");

        FILAMENT_CHECK_POSTCONDITION(!mPaused) <<
                "CommandStream is full, but since the rendering thread is paused, "
@@ -146,7 +146,7 @@ std::vector<CommandBufferQueue::Range> CommandBufferQueue::waitForCommands() con
    if (!UTILS_HAS_THREADING) {
        return std::move(mCommandBuffersToExecute);
    }
-    std::unique_lock lock(mLock);
+    std::unique_lock<utils::Mutex> lock(mLock);
    while ((mCommandBuffersToExecute.empty() || mPaused) && !mExitRequested) {
        mCondition.wait(lock);
    }
@@ -156,7 +156,7 @@ std::vector<CommandBufferQueue::Range> CommandBufferQueue::waitForCommands() con
 void CommandBufferQueue::releaseBuffer(CommandBufferQueue::Range const& buffer) {
    size_t const used = std::distance(
            static_cast<char const*>(buffer.begin), static_cast<char const*>(buffer.end));
-    std::lock_guard const lock(mLock);
+    std::lock_guard<utils::Mutex> const lock(mLock);
    mFreeSpace += used;
    mCondition.notify_one();
 }
@@ -16,19 +16,15 @@

 #include "private/backend/CommandStream.h"

-#include <private/utils/Tracing.h>
-
 #if DEBUG_COMMAND_STREAM
 #include <utils/CallStack.h>
 #endif

-#include <private/utils/Tracing.h>
-
-#include <utils/Logger.h>
-#include <utils/Profiler.h>
 #include <utils/compiler.h>
+#include <utils/Log.h>
 #include <utils/ostream.h>
-#include <utils/sstream.h>
+#include <utils/Profiler.h>
+#include <utils/Systrace.h>

 #include <cstddef>
 #include <functional>
@@ -83,13 +79,12 @@ CommandStream::CommandStream(Driver& driver, CircularBuffer& buffer) noexcept
 }

 void CommandStream::execute(void* buffer) {
-    // NOTE: we can't use FILAMENT_TRACING_CALL() or similar here because, execute() below, also
+    // NOTE: we can't use SYSTRACE_CALL() or similar here because, execute() below, also
    // uses systrace BEGIN/END and the END is not guaranteed to be happening in this scope.

    Profiler profiler;

-
-    if constexpr (FILAMENT_TRACING_ENABLED) {
+    if (SYSTRACE_TAG) {
        if (UTILS_UNLIKELY(mUsePerformanceCounter)) {
            // we want to remove all this when tracing is completely disabled
            profiler.resetEvents(Profiler::EV_CPU_CYCLES  | Profiler::EV_BPU_MISSES);
@@ -105,17 +100,17 @@ void CommandStream::execute(void* buffer) {
        }
    });

-    if constexpr (FILAMENT_TRACING_ENABLED) {
+    if (SYSTRACE_TAG) {
        if (UTILS_UNLIKELY(mUsePerformanceCounter)) {
            // we want to remove all this when tracing is completely disabled
            profiler.stop();
            UTILS_UNUSED Profiler::Counters const counters = profiler.readCounters();
-            FILAMENT_TRACING_CONTEXT(FILAMENT_TRACING_CATEGORY_FILAMENT);
-            FILAMENT_TRACING_VALUE(FILAMENT_TRACING_CATEGORY_FILAMENT, "GLThread (I)", counters.getInstructions());
-            FILAMENT_TRACING_VALUE(FILAMENT_TRACING_CATEGORY_FILAMENT, "GLThread (C)", counters.getCpuCycles());
-            FILAMENT_TRACING_VALUE(FILAMENT_TRACING_CATEGORY_FILAMENT, "GLThread (CPI x10)", counters.getCPI() * 10);
-            FILAMENT_TRACING_VALUE(FILAMENT_TRACING_CATEGORY_FILAMENT, "GLThread (BPU miss)", counters.getBranchMisses());
-            FILAMENT_TRACING_VALUE(FILAMENT_TRACING_CATEGORY_FILAMENT, "GLThread (I / BPU miss)",
+            SYSTRACE_CONTEXT();
+            SYSTRACE_VALUE32("GLThread (I)", counters.getInstructions());
+            SYSTRACE_VALUE32("GLThread (C)", counters.getCpuCycles());
+            SYSTRACE_VALUE32("GLThread (CPI x10)", counters.getCPI() * 10);
+            SYSTRACE_VALUE32("GLThread (BPU miss)", counters.getBranchMisses());
+            SYSTRACE_VALUE32("GLThread (I / BPU miss)",
                    counters.getInstructions() / counters.getBranchMisses());
        }
    }
@@ -132,10 +127,9 @@ void CommandType<void (Driver::*)(ARGS...)>::Command<METHOD>::log(std::index_seq
 #if DEBUG_COMMAND_STREAM
    static_assert(UTILS_HAS_RTTI, "DEBUG_COMMAND_STREAM can only be used with RTTI");
    std::string command = utils::CallStack::demangleTypeName(typeid(Command).name()).c_str();
-    DLOG(INFO) << extractMethodName(command) << " : size=" << sizeof(Command);
-    utils::io::sstream parameterPack;
-    printParameterPack(parameterPack, std::get<I>(mArgs)...);
-    DLOG(INFO) << "\t" << parameterPack.c_str();
+    slog.d << extractMethodName(command) << " : size=" << sizeof(Command) << "\n\t";
+    printParameterPack(slog.d, std::get<I>(mArgs)...);
+    slog.d << io::endl;
 #endif
 }

@@ -20,9 +20,8 @@
 #include "private/backend/Driver.h"
 #include "private/backend/CommandStream.h"

-#include <private/utils/Tracing.h>
-
 #include <utils/compiler.h>
+#include <utils/Systrace.h>

 #include <utility>

@@ -39,7 +38,7 @@
 #if DEBUG_LEVEL == DEBUG_LEVEL_NONE
 #   define SYSTRACE()
 #elif DEBUG_LEVEL == DEBUG_LEVEL_SYSTRACE
-#   define SYSTRACE() FILAMENT_TRACING_CALL(FILAMENT_TRACING_CATEGORY_FILAMENT);
+#   define SYSTRACE() SYSTRACE_CALL();
 #else
 #   error "invalid debug level"
 #endif
@@ -16,7 +16,7 @@

 #include "CompilerThreadPool.h"

-#include <private/utils/Tracing.h>
+#include <utils/Systrace.h>

 #include <memory>

@@ -41,7 +41,7 @@ void CompilerThreadPool::init(uint32_t threadCount,

    for (size_t i = 0; i < threadCount; i++) {
        mCompilerThreads.emplace_back([this, setup, cleanup]() {
-            FILAMENT_TRACING_CONTEXT(FILAMENT_TRACING_CATEGORY_FILAMENT);
+            SYSTRACE_CONTEXT();

            (*setup)();

@@ -54,7 +54,7 @@ void CompilerThreadPool::init(uint32_t threadCount,
                                    [](auto&& q) { return q.empty(); }));
                });

-                FILAMENT_TRACING_VALUE(FILAMENT_TRACING_CATEGORY_FILAMENT, "CompilerThreadPool Jobs",
+                SYSTRACE_VALUE32("CompilerThreadPool Jobs",
                        mQueues[0].size() + mQueues[1].size());

                if (UTILS_LIKELY(!mExitRequested)) {
@@ -23,12 +23,11 @@
 #include <backend/BufferDescriptor.h>
 #include <backend/DriverEnums.h>

-#include <private/utils/Tracing.h>
-
-#include <utils/Logger.h>
 #include <utils/compiler.h>
 #include <utils/debug.h>
+#include <utils/Log.h>
 #include <utils/ostream.h>
+#include <utils/Systrace.h>

 #include <math/half.h>
 #include <math/vec2.h>
@@ -149,34 +148,33 @@ void DriverBase::scheduleRelease(AcquiredImage const& image) noexcept {
 void DriverBase::debugCommandBegin(CommandStream* cmds, bool synchronous, const char* methodName) noexcept {
    if constexpr (bool(FILAMENT_DEBUG_COMMANDS > FILAMENT_DEBUG_COMMANDS_NONE)) {
        if constexpr (bool(FILAMENT_DEBUG_COMMANDS & FILAMENT_DEBUG_COMMANDS_LOG)) {
-            DLOG(INFO) << methodName;
+            utils::slog.d << methodName << utils::io::endl;
        }
        if constexpr (bool(FILAMENT_DEBUG_COMMANDS & FILAMENT_DEBUG_COMMANDS_SYSTRACE)) {
-            FILAMENT_TRACING_CONTEXT(FILAMENT_TRACING_CATEGORY_FILAMENT);
-            FILAMENT_TRACING_NAME_BEGIN(FILAMENT_TRACING_CATEGORY_FILAMENT, methodName);
+            SYSTRACE_CONTEXT();
+            SYSTRACE_NAME_BEGIN(methodName);

            if (!synchronous) {
                cmds->queueCommand([=]() {
-                    FILAMENT_TRACING_CONTEXT(FILAMENT_TRACING_CATEGORY_FILAMENT);
-                    FILAMENT_TRACING_NAME_BEGIN(FILAMENT_TRACING_CATEGORY_FILAMENT, methodName);
+                    SYSTRACE_CONTEXT();
+                    SYSTRACE_NAME_BEGIN(methodName);
                });
            }
        }
    }
 }

-void DriverBase::debugCommandEnd(CommandStream* cmds, bool synchronous,
-        const char* methodName) noexcept {
+void DriverBase::debugCommandEnd(CommandStream* cmds, bool synchronous, const char* methodName) noexcept {
    if constexpr (bool(FILAMENT_DEBUG_COMMANDS > FILAMENT_DEBUG_COMMANDS_NONE)) {
        if constexpr (bool(FILAMENT_DEBUG_COMMANDS & FILAMENT_DEBUG_COMMANDS_SYSTRACE)) {
            if (!synchronous) {
                cmds->queueCommand([]() {
-                    FILAMENT_TRACING_CONTEXT(FILAMENT_TRACING_CATEGORY_FILAMENT);
-                    FILAMENT_TRACING_NAME_END(FILAMENT_TRACING_CATEGORY_FILAMENT);
+                    SYSTRACE_CONTEXT();
+                    SYSTRACE_NAME_END();
                });
            }
-            FILAMENT_TRACING_CONTEXT(FILAMENT_TRACING_CATEGORY_FILAMENT);
-            FILAMENT_TRACING_NAME_END(FILAMENT_TRACING_CATEGORY_FILAMENT);
+            SYSTRACE_CONTEXT();
+            SYSTRACE_NAME_END();
        }
    }
 }
@@ -20,7 +20,7 @@

 #include <utils/Allocator.h>
 #include <utils/CString.h>
-#include <utils/Logger.h>
+#include <utils/Log.h>
 #include <utils/Panic.h>
 #include <utils/compiler.h>
 #include <utils/debug.h>
@@ -57,8 +57,8 @@ HandleAllocator<P0, P1, P2>::Allocator::Allocator(AreaPolicy::HeapArea const& ar
    size_t const maxHeapSize = std::min(area.size(), HANDLE_INDEX_MASK * getAlignment());

    if (UTILS_UNLIKELY(maxHeapSize != area.size())) {
-        LOG(WARNING) << "HandleAllocator heap size reduced to " << maxHeapSize << " from "
-                     << area.size();
+        slog.w << "HandleAllocator heap size reduced to "
+               << maxHeapSize << " from " << area.size() << io::endl;
    }

    // make sure we start with a clean arena. This is needed to ensure that all blocks start
@@ -17,7 +17,6 @@
 #include <backend/Platform.h>

 #include <utils/compiler.h>
-#include <utils/ostream.h>

 #include <atomic>
 #include <utility>
@@ -16,8 +16,7 @@

 #include <private/backend/PlatformFactory.h>

-#include <private/utils/Tracing.h>
-
+#include <utils/Systrace.h>
 #include <utils/debug.h>

 // We need to keep this up top for the linux (X11) name collisions.
@@ -86,7 +85,7 @@ namespace filament::backend {
 // responsible for destroying it. Initialization of the backend API is deferred until
 // createDriver(). The passed-in backend hint is replaced with the resolved backend.
 Platform* PlatformFactory::create(Backend* backend) noexcept {
-    FILAMENT_TRACING_CALL(FILAMENT_TRACING_CATEGORY_FILAMENT);
+    SYSTRACE_CALL();
    assert_invariant(backend);

 #if defined(__ANDROID__)
@@ -17,7 +17,7 @@
 #ifndef TNT_FILAMENT_BACKEND_SYSTRACEPROFILE_H
 #define TNT_FILAMENT_BACKEND_SYSTRACEPROFILE_H

-#include <private/utils/Tracing.h>
+#include <utils/Systrace.h>

 #define PROFILE_SCOPE(marker)       SYSTRACE_NAME(marker)

@@ -50,7 +50,7 @@ JavaVM* VirtualMachineEnv::getVirtualMachine() {
 */
 UTILS_PUBLIC
 UTILS_NOINLINE
-jint VirtualMachineEnv::JNI_OnLoad(JavaVM* vm) {
+jint VirtualMachineEnv::JNI_OnLoad(JavaVM* vm) noexcept {
    std::lock_guard const lock(sLock);
    if (sVirtualMachine) {
        // It doesn't make sense for JNI_OnLoad() to be called more than once
@@ -77,7 +77,7 @@ VirtualMachineEnv& VirtualMachineEnv::get() noexcept {
 }

 UTILS_NOINLINE
-JNIEnv* VirtualMachineEnv::getThreadEnvironment() {
+JNIEnv* VirtualMachineEnv::getThreadEnvironment() noexcept {
    JavaVM* const vm = getVirtualMachine();
    JNIEnv* env = nullptr;
    jint const result = vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6);
@@ -101,7 +101,7 @@ VirtualMachineEnv::~VirtualMachineEnv() noexcept {
 }

 UTILS_NOINLINE
-JNIEnv* VirtualMachineEnv::getEnvironmentSlow() {
+JNIEnv* VirtualMachineEnv::getEnvironmentSlow() noexcept {
    FILAMENT_CHECK_PRECONDITION(mVirtualMachine)
            << "JNI_OnLoad() has not been called";

@@ -19,8 +19,8 @@
 #include "MetalContext.h"
 #include "MetalUtils.h"

-#include <utils/Logger.h>
 #include <utils/Panic.h>
+#include <utils/Log.h>

 namespace filament::backend {

@@ -323,7 +323,7 @@ id<MTLFunction> MetalBlitter::compileFragmentFunction(BlitFunctionKey key) const
    if (!library || !function) {
        if (error) {
            auto description = [error.localizedDescription cStringUsingEncoding:NSUTF8StringEncoding];
-            LOG(ERROR) << description;
+            utils::slog.e << description << utils::io::endl;
        }
    }
    FILAMENT_CHECK_POSTCONDITION(library && function)
@@ -349,7 +349,7 @@ id<MTLFunction> MetalBlitter::getBlitVertexFunction() {
    if (!library || !function) {
        if (error) {
            auto description = [error.localizedDescription cStringUsingEncoding:NSUTF8StringEncoding];
-            LOG(ERROR) << description;
+            utils::slog.e << description << utils::io::endl;
        }
    }
    FILAMENT_CHECK_POSTCONDITION(library && function)
@@ -19,8 +19,6 @@

 #include "MetalContext.h"

-#include <utils/Panic.h>
-
 namespace filament {
 namespace backend {

@@ -18,8 +18,8 @@

 #include "MetalContext.h"

-#include <utils/Logger.h>
 #include <utils/Panic.h>
+#include <utils/Log.h>
 #include <utils/trap.h>

 #include <thread>
@@ -77,7 +77,8 @@ void MetalBufferPool::releaseBuffer(MetalBufferPoolEntry const *stage) noexcept

    auto iter = mUsedStages.find(stage);
    if (iter == mUsedStages.end()) {
-        LOG(ERROR) << "Unknown Metal buffer: " << stage->capacity << " bytes";
+        utils::slog.e << "Unknown Metal buffer: " << stage->capacity << " bytes"
+                << utils::io::endl;
        return;
    }
    stage->lastAccessed = mCurrentFrame;
@@ -18,9 +18,8 @@

 #include "MetalHandles.h"

-#include <utils/FixedCapacityVector.h>
-#include <utils/Logger.h>
 #include <utils/debug.h>
+#include <utils/FixedCapacityVector.h>

 #include <utility>

@@ -113,8 +112,8 @@ id<MTLCommandBuffer> getPendingCommandBuffer(MetalContext* context) {
        auto errorCode = (MTLCommandBufferError)buffer.error.code;
        if (@available(macOS 11.0, *)) {
            if (errorCode == MTLCommandBufferErrorMemoryless) {
-                LOG(WARNING) << "Metal: memoryless geometry limit reached. Continuing with private "
-                                "storage mode.";
+                utils::slog.w << "Metal: memoryless geometry limit reached. "
+                        "Continuing with private storage mode." << utils::io::endl;
                context->memorylessLimitsReached = true;
            }
        }
@@ -38,10 +38,10 @@
 #include <Metal/Metal.h>
 #include <QuartzCore/QuartzCore.h>

-#include <utils/Invocable.h>
-#include <utils/Logger.h>
+#include <utils/Log.h>
 #include <utils/Panic.h>
 #include <utils/sstream.h>
+#include <utils/Invocable.h>

 #include <algorithm>

@@ -78,18 +78,20 @@ Driver* MetalDriverFactory::create(PlatformMetal* const platform, const Platform
    //    MetalVertexBufferInfo        : 552       moderate
    // -- less than or equal to 552 bytes

-    DLOG(INFO) << "MetalSwapChain: " << sizeof(MetalSwapChain);
-    DLOG(INFO) << "MetalBufferObject: " << sizeof(MetalBufferObject);
-    DLOG(INFO) << "MetalVertexBuffer: " << sizeof(MetalVertexBuffer);
-    DLOG(INFO) << "MetalVertexBufferInfo: " << sizeof(MetalVertexBufferInfo);
-    DLOG(INFO) << "MetalIndexBuffer: " << sizeof(MetalIndexBuffer);
-    DLOG(INFO) << "MetalRenderPrimitive: " << sizeof(MetalRenderPrimitive);
-    DLOG(INFO) << "MetalTexture: " << sizeof(MetalTexture);
-    DLOG(INFO) << "MetalTimerQuery: " << sizeof(MetalTimerQuery);
-    DLOG(INFO) << "HwStream: " << sizeof(HwStream);
-    DLOG(INFO) << "MetalRenderTarget: " << sizeof(MetalRenderTarget);
-    DLOG(INFO) << "MetalFence: " << sizeof(MetalFence);
-    DLOG(INFO) << "MetalProgram: " << sizeof(MetalProgram);
+    utils::slog.d
+           << "\nMetalSwapChain: " << sizeof(MetalSwapChain)
+           << "\nMetalBufferObject: " << sizeof(MetalBufferObject)
+           << "\nMetalVertexBuffer: " << sizeof(MetalVertexBuffer)
+           << "\nMetalVertexBufferInfo: " << sizeof(MetalVertexBufferInfo)
+           << "\nMetalIndexBuffer: " << sizeof(MetalIndexBuffer)
+           << "\nMetalRenderPrimitive: " << sizeof(MetalRenderPrimitive)
+           << "\nMetalTexture: " << sizeof(MetalTexture)
+           << "\nMetalTimerQuery: " << sizeof(MetalTimerQuery)
+           << "\nHwStream: " << sizeof(HwStream)
+           << "\nMetalRenderTarget: " << sizeof(MetalRenderTarget)
+           << "\nMetalFence: " << sizeof(MetalFence)
+           << "\nMetalProgram: " << sizeof(MetalProgram)
+           << utils::io::endl;
 #endif
    return MetalDriver::create(platform, driverConfig);
 }
@@ -133,18 +135,19 @@ MetalDriver::MetalDriver(

    initializeSupportedGpuFamilies(mContext);

-    LOG(INFO) << "Supported GPU families: ";
+    utils::slog.v << "Supported GPU families: " << utils::io::endl;
    if (mContext->highestSupportedGpuFamily.common > 0) {
-        LOG(INFO) << "  MTLGPUFamilyCommon" << (int) mContext->highestSupportedGpuFamily.common;
+        utils::slog.v << "  MTLGPUFamilyCommon" << (int) mContext->highestSupportedGpuFamily.common << utils::io::endl;
    }
    if (mContext->highestSupportedGpuFamily.apple > 0) {
-        LOG(INFO) << "  MTLGPUFamilyApple" << (int) mContext->highestSupportedGpuFamily.apple;
+        utils::slog.v << "  MTLGPUFamilyApple" << (int) mContext->highestSupportedGpuFamily.apple << utils::io::endl;
    }
    if (mContext->highestSupportedGpuFamily.mac > 0) {
-        LOG(INFO) << "  MTLGPUFamilyMac" << (int) mContext->highestSupportedGpuFamily.mac;
+        utils::slog.v << "  MTLGPUFamilyMac" << (int) mContext->highestSupportedGpuFamily.mac << utils::io::endl;
    }
-    LOG(INFO) << "Features:";
-    LOG(INFO) << "  readWriteTextureSupport: " << (bool) mContext->device.readWriteTextureSupport;
+    utils::slog.v << "Features:" << utils::io::endl;
+    utils::slog.v << "  readWriteTextureSupport: " <<
+            (bool) mContext->device.readWriteTextureSupport << utils::io::endl;

    // In order to support texture swizzling, the GPU needs to support it and the system be running
    // iOS 13+.
@@ -585,7 +588,7 @@ void MetalDriver::createProgramR(Handle<HwProgram> rph, Program&& program) {
 #if FILAMENT_METAL_DEBUG_LOG
    auto handleId = rph.getId();
    DEBUG_LOG("createProgramR(rph = %d, program = ", handleId);
-    DLOG(INFO) << program;
+    utils::slog.d << program << utils::io::endl;
 #endif
    construct_handle<MetalProgram>(rph, *mContext, std::move(program));
 }
@@ -669,8 +672,22 @@ void MetalDriver::createTimerQueryR(Handle<HwTimerQuery> tqh, int) {
    // nothing to do, timer query was constructed in createTimerQueryS
 }

-UTILS_UNUSED
-static const char* toString(ShaderStageFlags flags) {
+const char* toString(DescriptorType type) {
+    switch (type) {
+        case DescriptorType::UNIFORM_BUFFER:
+            return "UNIFORM_BUFFER";
+        case DescriptorType::SHADER_STORAGE_BUFFER:
+            return "SHADER_STORAGE_BUFFER";
+        case DescriptorType::SAMPLER:
+            return "SAMPLER";
+        case DescriptorType::INPUT_ATTACHMENT:
+            return "INPUT_ATTACHMENT";
+        case DescriptorType::SAMPLER_EXTERNAL:
+            return "SAMPLER_EXTERNAL";
+    }
+}
+
+const char* toString(ShaderStageFlags flags) {
    std::vector<const char*> stages;
    if (any(flags & ShaderStageFlags::VERTEX)) {
        stages.push_back("VERTEX");
@@ -704,25 +721,15 @@ const char* toString(DescriptorFlags flags) {

 void MetalDriver::createDescriptorSetLayoutR(
        Handle<HwDescriptorSetLayout> dslh, DescriptorSetLayout&& info) {
-#if FILAMENT_METAL_DEBUG_LOG == 1
-    const char* labelStr = "";
-    std::visit([&labelStr](auto&& arg) {
-        using T = std::decay_t<decltype(arg)>;
-        if constexpr (std::is_same_v<T, utils::CString> || std::is_same_v<T, utils::StaticString>) {
-            labelStr = arg.c_str();
-        }
-    }, info.label);
    std::sort(info.bindings.begin(), info.bindings.end(),
            [](const auto& a, const auto& b) { return a.binding < b.binding; });
-    DEBUG_LOG("createDescriptorSetLayoutR(dslh = %d, info = { label = %s,\n", dslh.getId(),
-            labelStr);
+    DEBUG_LOG("createDescriptorSetLayoutR(dslh = %d, info = {\n", dslh.getId());
    for (size_t i = 0; i < info.bindings.size(); i++) {
        DEBUG_LOG("    {binding = %d, type = %s, count = %d, stage = %s, flags = %s},\n",
                info.bindings[i].binding, toString(info.bindings[i].type), info.bindings[i].count,
                toString(info.bindings[i].stageFlags), toString(info.bindings[i].flags));
    }
    DEBUG_LOG("})\n");
-#endif
    construct_handle<MetalDescriptorSetLayout>(dslh, std::move(info));
 }

@@ -2074,7 +2081,7 @@ void MetalDriver::dispatchCompute(Handle<HwProgram> program, math::uint3 workGro
                                                            error:&error];
    if (error) {
        auto description = [error.localizedDescription cStringUsingEncoding:NSUTF8StringEncoding];
-        LOG(ERROR) << description;
+        utils::slog.e << description << utils::io::endl;
    }
    assert_invariant(!error);

@@ -20,14 +20,14 @@
 #include "MetalEnums.h"
 #include "MetalUtils.h"

-#include <utils/Logger.h>
 #include <utils/Panic.h>
+#include <utils/Log.h>
 #include <utils/trap.h>

 #define NSERROR_CHECK(message)                                                                     \
    if (error) {                                                                                   \
        auto description = [error.localizedDescription cStringUsingEncoding:NSUTF8StringEncoding]; \
-        LOG(ERROR) << description;                                                                 \
+        utils::slog.e << description << utils::io::endl;                                           \
    }                                                                                              \
    FILAMENT_CHECK_POSTCONDITION(error == nil) << message;

@@ -27,11 +27,10 @@

 #include "private/backend/BackendUtils.h"

-#include <utils/Logger.h>
-#include <utils/Panic.h>
 #include <utils/compiler.h>
-#include <utils/debug.h>
+#include <utils/Panic.h>
 #include <utils/trap.h>
+#include <utils/debug.h>

 #include <math/scalar.h>

@@ -116,14 +115,14 @@ MetalSwapChain::MetalSwapChain(
      type(SwapChainType::CAMETALLAYER) {

    if (!(flags & SwapChain::CONFIG_TRANSPARENT) && !nativeWindow.opaque) {
-        LOG(WARNING) << "Warning: Filament SwapChain has no CONFIG_TRANSPARENT flag, but the "
-                        "CAMetaLayer("
-                     << (__bridge void*) nativeWindow << ") has .opaque set to NO.";
+        utils::slog.w << "Warning: Filament SwapChain has no CONFIG_TRANSPARENT flag, "
+                         "but the CAMetaLayer(" << (__bridge void*) nativeWindow << ")"
+                         " has .opaque set to NO." << utils::io::endl;
    }
    if ((flags & SwapChain::CONFIG_TRANSPARENT) && nativeWindow.opaque) {
-        LOG(WARNING) << "Warning: Filament SwapChain has the CONFIG_TRANSPARENT flag, but the "
-                        "CAMetaLayer("
-                     << (__bridge void*) nativeWindow << ") has .opaque set to YES.";
+        utils::slog.w << "Warning: Filament SwapChain has the CONFIG_TRANSPARENT flag, "
+                         "but the CAMetaLayer(" << (__bridge void*) nativeWindow << ")"
+                         " has .opaque set to YES." << utils::io::endl;
    }

    // Needed so we can use the SwapChain as a blit source.
@@ -1357,31 +1356,7 @@ id<MTLArgumentEncoder> MetalDescriptorSetLayout::getArgumentEncoderSlow(id<MTLDe
                [arguments addObject:bufferArgument];
                break;
            }
-            case DescriptorType::SAMPLER_2D_FLOAT:
-            case DescriptorType::SAMPLER_2D_INT:
-            case DescriptorType::SAMPLER_2D_UINT:
-            case DescriptorType::SAMPLER_2D_DEPTH:
-            case DescriptorType::SAMPLER_2D_ARRAY_FLOAT:
-            case DescriptorType::SAMPLER_2D_ARRAY_INT:
-            case DescriptorType::SAMPLER_2D_ARRAY_UINT:
-            case DescriptorType::SAMPLER_2D_ARRAY_DEPTH:
-            case DescriptorType::SAMPLER_CUBE_FLOAT:
-            case DescriptorType::SAMPLER_CUBE_INT:
-            case DescriptorType::SAMPLER_CUBE_UINT:
-            case DescriptorType::SAMPLER_CUBE_DEPTH:
-            case DescriptorType::SAMPLER_CUBE_ARRAY_FLOAT:
-            case DescriptorType::SAMPLER_CUBE_ARRAY_INT:
-            case DescriptorType::SAMPLER_CUBE_ARRAY_UINT:
-            case DescriptorType::SAMPLER_CUBE_ARRAY_DEPTH:
-            case DescriptorType::SAMPLER_3D_FLOAT:
-            case DescriptorType::SAMPLER_3D_INT:
-            case DescriptorType::SAMPLER_3D_UINT:
-            case DescriptorType::SAMPLER_2D_MS_FLOAT:
-            case DescriptorType::SAMPLER_2D_MS_INT:
-            case DescriptorType::SAMPLER_2D_MS_UINT:
-            case DescriptorType::SAMPLER_2D_MS_ARRAY_FLOAT:
-            case DescriptorType::SAMPLER_2D_MS_ARRAY_INT:
-            case DescriptorType::SAMPLER_2D_MS_ARRAY_UINT:
+            case DescriptorType::SAMPLER:
            case DescriptorType::SAMPLER_EXTERNAL: {
                MTLArgumentDescriptor* textureArgument = [MTLArgumentDescriptor argumentDescriptor];
                textureArgument.index = binding.binding * 2;
@@ -1407,9 +1382,6 @@ id<MTLArgumentEncoder> MetalDescriptorSetLayout::getArgumentEncoderSlow(id<MTLDe
                break;
        }
    }
-    if (arguments.count == 0) {
-        return nil;
-    }
    return [device newArgumentEncoderWithArguments:arguments];
 }

@@ -1470,9 +1442,6 @@ id<MTLBuffer> MetalDescriptorSet::finalizeAndGetBuffer(MetalDriver* driver, Shad

    id<MTLArgumentEncoder> encoder =
            layout->getArgumentEncoder(context.device, stage, textureTypes);
-    if (!encoder) {
-        return nil;
-    }

    {
        ScopedAllocationTimer timer("descriptor_set");
@@ -1503,31 +1472,7 @@ id<MTLBuffer> MetalDescriptorSet::finalizeAndGetBuffer(MetalDriver* driver, Shad
                           atIndex:binding.binding * 2];
                break;
            }
-            case DescriptorType::SAMPLER_2D_FLOAT:
-            case DescriptorType::SAMPLER_2D_INT:
-            case DescriptorType::SAMPLER_2D_UINT:
-            case DescriptorType::SAMPLER_2D_DEPTH:
-            case DescriptorType::SAMPLER_2D_ARRAY_FLOAT:
-            case DescriptorType::SAMPLER_2D_ARRAY_INT:
-            case DescriptorType::SAMPLER_2D_ARRAY_UINT:
-            case DescriptorType::SAMPLER_2D_ARRAY_DEPTH:
-            case DescriptorType::SAMPLER_CUBE_FLOAT:
-            case DescriptorType::SAMPLER_CUBE_INT:
-            case DescriptorType::SAMPLER_CUBE_UINT:
-            case DescriptorType::SAMPLER_CUBE_DEPTH:
-            case DescriptorType::SAMPLER_CUBE_ARRAY_FLOAT:
-            case DescriptorType::SAMPLER_CUBE_ARRAY_INT:
-            case DescriptorType::SAMPLER_CUBE_ARRAY_UINT:
-            case DescriptorType::SAMPLER_CUBE_ARRAY_DEPTH:
-            case DescriptorType::SAMPLER_3D_FLOAT:
-            case DescriptorType::SAMPLER_3D_INT:
-            case DescriptorType::SAMPLER_3D_UINT:
-            case DescriptorType::SAMPLER_2D_MS_FLOAT:
-            case DescriptorType::SAMPLER_2D_MS_INT:
-            case DescriptorType::SAMPLER_2D_MS_UINT:
-            case DescriptorType::SAMPLER_2D_MS_ARRAY_FLOAT:
-            case DescriptorType::SAMPLER_2D_MS_ARRAY_INT:
-            case DescriptorType::SAMPLER_2D_MS_ARRAY_UINT:
+            case DescriptorType::SAMPLER:
            case DescriptorType::SAMPLER_EXTERNAL: {
                auto found = textures.find(binding.binding);
                if (found == textures.end()) {
@@ -21,7 +21,6 @@
 #include <backend/Program.h>

 #include <utils/JobSystem.h>
-#include <utils/Logger.h>
 #include <utils/Mutex.h>

 #include <chrono>
@@ -148,7 +147,7 @@ bool MetalShaderCompiler::isParallelShaderCompileSupported() const noexcept {
            if (error) {
                auto description =
                        [error.localizedDescription cStringUsingEncoding:NSUTF8StringEncoding];
-                LOG(WARNING) << description;
+                utils::slog.w << description << utils::io::endl;
                errorMessage = error.localizedDescription;
            }
            PANIC_LOG("Failed to compile Metal program.");
@@ -179,7 +178,7 @@ bool MetalShaderCompiler::isParallelShaderCompileSupported() const noexcept {
            if (error) {
                auto description =
                        [error.localizedDescription cStringUsingEncoding:NSUTF8StringEncoding];
-                LOG(WARNING) << description;
+                utils::slog.w << description << utils::io::endl;
                errorMessage = error.localizedDescription;
            }
            PANIC_LOG("Failed to load main0 in Metal program.");
@@ -20,18 +20,17 @@
 #include <Metal/Metal.h>

 #include "private/backend/Driver.h"
+#include "backend/Program.h"

 #include <backend/DriverEnums.h>
-#include <backend/Program.h>

-#include <utils/bitset.h>
 #include <utils/FixedCapacityVector.h>
-#include <utils/Hash.h>
-#include <utils/Invocable.h>
-
-#include <tsl/robin_map.h>

 #include <memory>
+#include <tsl/robin_map.h>
+
+#include <utils/Hash.h>
+#include <utils/Invocable.h>

 namespace filament {
 namespace backend {
@@ -18,7 +18,7 @@

 #include "MetalEnums.h"

-#include <utils/Logger.h>
+#include <utils/Log.h>

 namespace filament {
 namespace backend {
@@ -95,7 +95,7 @@ id<MTLRenderPipelineState> PipelineStateCreator::operator()(id<MTLDevice> device
            [NSString stringWithFormat:@"Could not create Metal pipeline state: %@",
                error ? error.localizedDescription : @"unknown error"];
        auto description = [errorMessage cStringUsingEncoding:NSUTF8StringEncoding];
-        LOG(ERROR) << description;
+        utils::slog.e << description << utils::io::endl;
        [[NSException exceptionWithName:@"MetalRenderPipelineFailure"
                                 reason:errorMessage
                               userInfo:nil] raise];
@@ -155,7 +155,7 @@ id<MTLSamplerState> SamplerStateCreator::operator()(id<MTLDevice> device,
    // MTLSamplerDescriptor.
    // In practice, this means shadows are not supported when running in the simulator.
    if (![device supportsFeatureSet:MTLFeatureSet_iOS_GPUFamily3_v1]) {
-        LOG(WARNING) << "Warning: sample comparison not supported by this GPU";
+        utils::slog.w << "Warning: sample comparison not supported by this GPU" << utils::io::endl;
        samplerDescriptor.compareFunction = MTLCompareFunctionNever;
    }
 #endif
@@ -19,27 +19,19 @@

 #include "MetalDriverFactory.h"

-#include <utils/Logger.h>
+#include <utils/Log.h>

 #import <Foundation/Foundation.h>

 #include <atomic>
-#include <mutex>

 namespace filament::backend {

 struct PlatformMetalImpl {
-    std::mutex mLock;   // locks mDevice and mCommandQueue
-    id<MTLDevice> mDevice = nil;
    id<MTLCommandQueue> mCommandQueue = nil;
-
    // read form driver thread, read/written to from client thread
    std::atomic<PlatformMetal::DrawableFailureBehavior> mDrawableFailureBehavior =
            PlatformMetal::DrawableFailureBehavior::PANIC;
-
-    // These methods must be called with mLock held
-    void createDeviceImpl(MetalDevice& outDevice);
-    void createCommandQueueImpl(MetalDevice& device, MetalCommandQueue& outCommandQueue);
 };

 Platform* createDefaultMetalPlatform() {
@@ -53,65 +45,10 @@ PlatformMetal::~PlatformMetal() noexcept {
 }

 Driver* PlatformMetal::createDriver(void* /*sharedContext*/, const Platform::DriverConfig& driverConfig) noexcept {
-    pImpl->mDrawableFailureBehavior = driverConfig.metalDisablePanicOnDrawableFailure
-            ? DrawableFailureBehavior::ABORT_FRAME
-            : DrawableFailureBehavior::PANIC;
    return MetalDriverFactory::create(this, driverConfig);
 }

-
-bool PlatformMetal::initialize() noexcept {
-    std::lock_guard<std::mutex> lock(pImpl->mLock);
-
-    MetalDevice device{};
-    pImpl->createDeviceImpl(device);
-    if (device.device == nil) {
-        return false;
-    }
-
-    MetalCommandQueue commandQueue{};
-    pImpl->createCommandQueueImpl(device, commandQueue);
-    if (commandQueue.commandQueue == nil) {
-        return false;
-    }
-
-    return true;
-}
-
 void PlatformMetal::createDevice(MetalDevice& outDevice) noexcept {
-    std::lock_guard<std::mutex> lock(pImpl->mLock);
-    pImpl->createDeviceImpl(outDevice);
-}
-
-void PlatformMetal::createCommandQueue(
-        MetalDevice& device, MetalCommandQueue& outCommandQueue) noexcept {
-    std::lock_guard<std::mutex> lock(pImpl->mLock);
-    pImpl->createCommandQueueImpl(device, outCommandQueue);
-}
-
-void PlatformMetal::createAndEnqueueCommandBuffer(MetalCommandBuffer& outCommandBuffer) noexcept {
-    std::lock_guard<std::mutex> lock(pImpl->mLock);
-    id<MTLCommandBuffer> commandBuffer = [pImpl->mCommandQueue commandBuffer];
-    [commandBuffer enqueue];
-    outCommandBuffer.commandBuffer = commandBuffer;
-}
-
-void PlatformMetal::setDrawableFailureBehavior(DrawableFailureBehavior behavior) noexcept {
-    pImpl->mDrawableFailureBehavior = behavior;
-}
-
-PlatformMetal::DrawableFailureBehavior PlatformMetal::getDrawableFailureBehavior() const noexcept {
-    return pImpl->mDrawableFailureBehavior;
-}
-
-// -------------------------------------------------------------------------------------------------
-
-void PlatformMetalImpl::createDeviceImpl(MetalDevice& outDevice) {
-    if (mDevice) {
-        outDevice.device = mDevice;
-        return;
-    }
-
    id<MTLDevice> result;

 #if !defined(FILAMENT_IOS)
@@ -132,21 +69,32 @@ void PlatformMetalImpl::createDeviceImpl(MetalDevice& outDevice) {
        result = MTLCreateSystemDefaultDevice();
    }

-    LOG(INFO) << "Selected physical device '"
-              << [result.name cStringUsingEncoding:NSUTF8StringEncoding] << "'";
+    utils::slog.i << "Selected physical device '"
+                  << [result.name cStringUsingEncoding:NSUTF8StringEncoding] << "'"
+                  << utils::io::endl;

    outDevice.device = result;
-    mDevice = result;
 }

-void PlatformMetalImpl::createCommandQueueImpl(MetalDevice& device, MetalCommandQueue& outCommandQueue) {
-    if (mCommandQueue) {
-        outCommandQueue.commandQueue = mCommandQueue;
-        return;
-    }
-    mCommandQueue = [device.device newCommandQueue];
-    mCommandQueue.label = @"Filament";
-    outCommandQueue.commandQueue = mCommandQueue;
+void PlatformMetal::createCommandQueue(
+        MetalDevice& device, MetalCommandQueue& outCommandQueue) noexcept {
+    pImpl->mCommandQueue = [device.device newCommandQueue];
+    pImpl->mCommandQueue.label = @"Filament";
+    outCommandQueue.commandQueue = pImpl->mCommandQueue;
+}
+
+void PlatformMetal::createAndEnqueueCommandBuffer(MetalCommandBuffer& outCommandBuffer) noexcept {
+    id<MTLCommandBuffer> commandBuffer = [pImpl->mCommandQueue commandBuffer];
+    [commandBuffer enqueue];
+    outCommandBuffer.commandBuffer = commandBuffer;
+}
+
+void PlatformMetal::setDrawableFailureBehavior(DrawableFailureBehavior behavior) noexcept {
+    pImpl->mDrawableFailureBehavior = behavior;
+}
+
+PlatformMetal::DrawableFailureBehavior PlatformMetal::getDrawableFailureBehavior() const noexcept {
+    return pImpl->mDrawableFailureBehavior;
 }

 } // namespace filament
@@ -69,8 +69,9 @@ public:
        assert_invariant(set < MAX_DESCRIPTOR_SET_COUNT);
        assert_invariant(binding < MAX_DESCRIPTOR_COUNT);
        assert_invariant(entry.binding < 128); // we reserve 1 bit for the type right now
-        mStorage[set][binding] = { uint8_t(entry.binding),
-                                   DescriptorSetLayoutBinding::isSampler(entry.type) };
+        mStorage[set][binding] = { (uint8_t)entry.binding,
+                                   entry.type == DescriptorType::SAMPLER ||
+                                   entry.type == DescriptorType::SAMPLER_EXTERNAL };
        mActiveDescriptors[set].set(binding);
    }

@@ -95,32 +95,7 @@ GLDescriptorSet::GLDescriptorSet(OpenGLContext& gl, DescriptorSetLayoutHandle ds
                }
                break;
            }
-
-            case DescriptorType::SAMPLER_2D_FLOAT:
-            case DescriptorType::SAMPLER_2D_INT:
-            case DescriptorType::SAMPLER_2D_UINT:
-            case DescriptorType::SAMPLER_2D_DEPTH:
-            case DescriptorType::SAMPLER_2D_ARRAY_FLOAT:
-            case DescriptorType::SAMPLER_2D_ARRAY_INT:
-            case DescriptorType::SAMPLER_2D_ARRAY_UINT:
-            case DescriptorType::SAMPLER_2D_ARRAY_DEPTH:
-            case DescriptorType::SAMPLER_CUBE_FLOAT:
-            case DescriptorType::SAMPLER_CUBE_INT:
-            case DescriptorType::SAMPLER_CUBE_UINT:
-            case DescriptorType::SAMPLER_CUBE_DEPTH:
-            case DescriptorType::SAMPLER_CUBE_ARRAY_FLOAT:
-            case DescriptorType::SAMPLER_CUBE_ARRAY_INT:
-            case DescriptorType::SAMPLER_CUBE_ARRAY_UINT:
-            case DescriptorType::SAMPLER_CUBE_ARRAY_DEPTH:
-            case DescriptorType::SAMPLER_3D_FLOAT:
-            case DescriptorType::SAMPLER_3D_INT:
-            case DescriptorType::SAMPLER_3D_UINT:
-            case DescriptorType::SAMPLER_2D_MS_FLOAT:
-            case DescriptorType::SAMPLER_2D_MS_INT:
-            case DescriptorType::SAMPLER_2D_MS_UINT:
-            case DescriptorType::SAMPLER_2D_MS_ARRAY_FLOAT:
-            case DescriptorType::SAMPLER_2D_MS_ARRAY_INT:
-            case DescriptorType::SAMPLER_2D_MS_ARRAY_UINT:
+            case DescriptorType::SAMPLER:
            case DescriptorType::SAMPLER_EXTERNAL:
                if (UTILS_UNLIKELY(gl.isES2())) {
                    desc.emplace<SamplerGLES2>();
@@ -162,11 +137,8 @@ void GLDescriptorSet::update(OpenGLContext&,
    }, descriptors[binding].desc);
 }

-void GLDescriptorSet::update(OpenGLContext& gl, HandleAllocatorGL& handleAllocator,
-        descriptor_binding_t binding, TextureHandle th, SamplerParams params) noexcept {
-
-    GLTexture* t = th ? handleAllocator.handle_cast<GLTexture*>(th) : nullptr;
-
+void GLDescriptorSet::update(OpenGLContext& gl,
+        descriptor_binding_t binding, GLTexture* t, SamplerParams params) noexcept {
    assert_invariant(binding < descriptors.size());
    std::visit([=, &gl](auto&& arg) mutable {
        using T = std::decay_t<decltype(arg)>;
@@ -199,12 +171,20 @@ void GLDescriptorSet::update(OpenGLContext& gl, HandleAllocatorGL& handleAllocat
                }
            }

-            arg.handle = th;
+            arg.target = t ? t->gl.target : 0;
+            arg.id = t ? t->gl.id : 0;
+            arg.external = t ? t->gl.external :  false;
            if constexpr (std::is_same_v<T, Sampler> ||
                          std::is_same_v<T, SamplerWithAnisotropyWorkaround>) {
                if constexpr (std::is_same_v<T, SamplerWithAnisotropyWorkaround>) {
                    arg.anisotropy = float(1u << params.anisotropyLog2);
                }
+                if (t) {
+                    arg.ref = t->ref;
+                    arg.baseLevel = t->gl.baseLevel;
+                    arg.maxLevel = t->gl.maxLevel;
+                    arg.swizzle = t->gl.swizzle;
+                }
 #ifndef FILAMENT_SILENCE_NOT_SUPPORTED_BY_ES2
                arg.sampler = gl.getSampler(params);
 #else
@@ -220,39 +200,39 @@ void GLDescriptorSet::update(OpenGLContext& gl, HandleAllocatorGL& handleAllocat
    }, descriptors[binding].desc);
 }

+template<typename T>
 void GLDescriptorSet::updateTextureView(OpenGLContext& gl,
-        HandleAllocatorGL& handleAllocator, GLuint unit, GLTexture const* t) noexcept {
+        HandleAllocatorGL& handleAllocator, GLuint unit, T const& desc) noexcept {
    // The common case is that we don't have a ref handle (we only have one if
    // the texture ever had a View on it).
-    assert_invariant(t);
-    assert_invariant(t->ref);
-    GLTextureRef* const ref = handleAllocator.handle_cast<GLTextureRef*>(t->ref);
-    if (UTILS_UNLIKELY((t->gl.baseLevel != ref->baseLevel || t->gl.maxLevel != ref->maxLevel))) {
+    assert_invariant(desc.ref);
+    GLTextureRef* const ref = handleAllocator.handle_cast<GLTextureRef*>(desc.ref);
+    if (UTILS_UNLIKELY((desc.baseLevel != ref->baseLevel || desc.maxLevel != ref->maxLevel))) {
        // If we have views, then it's still uncommon that we'll switch often
        // handle the case where we reset to the original texture
-        GLint baseLevel = GLint(t->gl.baseLevel); // NOLINT(*-signed-char-misuse)
-        GLint maxLevel = GLint(t->gl.maxLevel); // NOLINT(*-signed-char-misuse)
+        GLint baseLevel = GLint(desc.baseLevel); // NOLINT(*-signed-char-misuse)
+        GLint maxLevel = GLint(desc.maxLevel); // NOLINT(*-signed-char-misuse)
        if (baseLevel > maxLevel) {
            baseLevel = 0;
            maxLevel = 1000; // per OpenGL spec
        }
        // that is very unfortunate that we have to call activeTexture here
        gl.activeTexture(unit);
-        glTexParameteri(t->gl.target, GL_TEXTURE_BASE_LEVEL, baseLevel);
-        glTexParameteri(t->gl.target, GL_TEXTURE_MAX_LEVEL,  maxLevel);
-        ref->baseLevel = t->gl.baseLevel;
-        ref->maxLevel = t->gl.maxLevel;
+        glTexParameteri(desc.target, GL_TEXTURE_BASE_LEVEL, baseLevel);
+        glTexParameteri(desc.target, GL_TEXTURE_MAX_LEVEL,  maxLevel);
+        ref->baseLevel = desc.baseLevel;
+        ref->maxLevel = desc.maxLevel;
    }
-    if (UTILS_UNLIKELY(t->gl.swizzle != ref->swizzle)) {
+    if (UTILS_UNLIKELY(desc.swizzle != ref->swizzle)) {
        using namespace GLUtils;
        gl.activeTexture(unit);
 #if !defined(__EMSCRIPTEN__)  && !defined(FILAMENT_SILENCE_NOT_SUPPORTED_BY_ES2)
-        glTexParameteri(t->gl.target, GL_TEXTURE_SWIZZLE_R, (GLint)getSwizzleChannel(t->gl.swizzle[0]));
-        glTexParameteri(t->gl.target, GL_TEXTURE_SWIZZLE_G, (GLint)getSwizzleChannel(t->gl.swizzle[1]));
-        glTexParameteri(t->gl.target, GL_TEXTURE_SWIZZLE_B, (GLint)getSwizzleChannel(t->gl.swizzle[2]));
-        glTexParameteri(t->gl.target, GL_TEXTURE_SWIZZLE_A, (GLint)getSwizzleChannel(t->gl.swizzle[3]));
+        glTexParameteri(desc.target, GL_TEXTURE_SWIZZLE_R, (GLint)getSwizzleChannel(desc.swizzle[0]));
+        glTexParameteri(desc.target, GL_TEXTURE_SWIZZLE_G, (GLint)getSwizzleChannel(desc.swizzle[1]));
+        glTexParameteri(desc.target, GL_TEXTURE_SWIZZLE_B, (GLint)getSwizzleChannel(desc.swizzle[2]));
+        glTexParameteri(desc.target, GL_TEXTURE_SWIZZLE_A, (GLint)getSwizzleChannel(desc.swizzle[3]));
 #endif
-        ref->swizzle = t->gl.swizzle;
+        ref->swizzle = desc.swizzle;
    }
 }

@@ -305,31 +285,27 @@ void GLDescriptorSet::bind(
                }
            } else if constexpr (std::is_same_v<T, Sampler>) {
                GLuint const unit = p.getTextureUnit(set, binding);
-
-
-                if (arg.handle) {
-                    GLTexture const* const t = handleAllocator.handle_cast<GLTexture*>(arg.handle);
-                    gl.bindTexture(unit, t->gl.target, t->gl.id, t->gl.external);
+                if (arg.target) {
+                    gl.bindTexture(unit, arg.target, arg.id, arg.external);
                    gl.bindSampler(unit, arg.sampler);
-                    if (UTILS_UNLIKELY(t->ref)) {
-                        updateTextureView(gl, handleAllocator, unit, t);
+                    if (UTILS_UNLIKELY(arg.ref)) {
+                        updateTextureView(gl, handleAllocator, unit, arg);
                    }
                } else {
                    gl.unbindTextureUnit(unit);
                }
            } else if constexpr (std::is_same_v<T, SamplerWithAnisotropyWorkaround>) {
                GLuint const unit = p.getTextureUnit(set, binding);
-                if (arg.handle) {
-                    GLTexture const* const t = handleAllocator.handle_cast<GLTexture*>(arg.handle);
-                    gl.bindTexture(unit, t->gl.target, t->gl.id, t->gl.external);
+                if (arg.target) {
+                    gl.bindTexture(unit, arg.target, arg.id, arg.external);
                    gl.bindSampler(unit, arg.sampler);
-                    if (UTILS_UNLIKELY(t->ref)) {
-                        updateTextureView(gl, handleAllocator, unit, t);
+                    if (UTILS_UNLIKELY(arg.ref)) {
+                        updateTextureView(gl, handleAllocator, unit, arg);
                    }
 #if defined(GL_EXT_texture_filter_anisotropic)
                    // Driver claims to support anisotropic filtering, but it fails when set on
                    // the sampler, we have to set it on the texture instead.
-                    glTexParameterf(t->gl.target, GL_TEXTURE_MAX_ANISOTROPY_EXT,
+                    glTexParameterf(arg.target, GL_TEXTURE_MAX_ANISOTROPY_EXT,
                            std::min(gl.gets.max_anisotropy, float(arg.anisotropy)));
 #endif
                } else {
@@ -338,20 +314,19 @@ void GLDescriptorSet::bind(
            } else if constexpr (std::is_same_v<T, SamplerGLES2>) {
                // in ES2 the sampler parameters need to be set on the texture itself
                GLuint const unit = p.getTextureUnit(set, binding);
-                if (arg.handle) {
-                    GLTexture const* const t = handleAllocator.handle_cast<GLTexture*>(arg.handle);
-                    gl.bindTexture(unit, t->gl.target, t->gl.id, t->gl.external);
+                if (arg.target) {
+                    gl.bindTexture(unit, arg.target, arg.id, arg.external);
                    SamplerParams const params = arg.params;
-                    glTexParameteri(t->gl.target, GL_TEXTURE_MIN_FILTER,
+                    glTexParameteri(arg.target, GL_TEXTURE_MIN_FILTER,
                            (GLint)GLUtils::getTextureFilter(params.filterMin));
-                    glTexParameteri(t->gl.target, GL_TEXTURE_MAG_FILTER,
+                    glTexParameteri(arg.target, GL_TEXTURE_MAG_FILTER,
                            (GLint)GLUtils::getTextureFilter(params.filterMag));
-                    glTexParameteri(t->gl.target, GL_TEXTURE_WRAP_S,
+                    glTexParameteri(arg.target, GL_TEXTURE_WRAP_S,
                            (GLint)GLUtils::getWrapMode(params.wrapS));
-                    glTexParameteri(t->gl.target, GL_TEXTURE_WRAP_T,
+                    glTexParameteri(arg.target, GL_TEXTURE_WRAP_T,
                            (GLint)GLUtils::getWrapMode(params.wrapT));
 #if defined(GL_EXT_texture_filter_anisotropic)
-                    glTexParameterf(t->gl.target, GL_TEXTURE_MAX_ANISOTROPY_EXT,
+                    glTexParameterf(arg.target, GL_TEXTURE_MAX_ANISOTROPY_EXT,
                            std::min(gl.gets.max_anisotropy, arg.anisotropy));
 #endif
                } else {
@@ -360,7 +335,7 @@ void GLDescriptorSet::bind(
            }
        }, entry.desc);
    });
-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void GLDescriptorSet::validate(HandleAllocatorGL& allocator,
@@ -59,8 +59,8 @@ struct GLDescriptorSet : public HwDescriptorSet {
            descriptor_binding_t binding, GLBufferObject* bo, size_t offset, size_t size) noexcept;

    // update a sampler descriptor in the set
-    void update(OpenGLContext& gl, HandleAllocatorGL& handleAllocator,
-            descriptor_binding_t binding, TextureHandle th, SamplerParams params) noexcept;
+    void update(OpenGLContext& gl,
+            descriptor_binding_t binding, GLTexture* t, SamplerParams params) noexcept;

    // conceptually bind the set to the command buffer
    void bind(
@@ -111,19 +111,46 @@ private:

    // A sampler descriptor
    struct Sampler {
-        TextureHandle handle;                   // 4
+        uint16_t target;                        // 2 (GLenum)
+        bool external = false;                  // 1
+        bool reserved = false;                  // 1
+        GLuint id = 0;                          // 4
        GLuint sampler = 0;                     // 4
+        Handle<GLTextureRef> ref;               // 4
+        int8_t baseLevel = 0x7f;                // 1
+        int8_t maxLevel = -1;                   // 1
+        std::array<TextureSwizzle, 4> swizzle{  // 4
+                TextureSwizzle::CHANNEL_0,
+                TextureSwizzle::CHANNEL_1,
+                TextureSwizzle::CHANNEL_2,
+                TextureSwizzle::CHANNEL_3
+        };
    };

    struct SamplerWithAnisotropyWorkaround {
-        TextureHandle handle;                   // 4
+        uint16_t target;                        // 2 (GLenum)
+        bool external = false;                  // 1
+        bool reserved = false;                  // 1
+        GLuint id = 0;                          // 4
        GLuint sampler = 0;                     // 4
+        Handle<GLTextureRef> ref;               // 4
        math::half anisotropy = 1.0f;           // 2
+        int8_t baseLevel = 0x7f;                // 1
+        int8_t maxLevel = -1;                   // 1
+        std::array<TextureSwizzle, 4> swizzle{  // 4
+                TextureSwizzle::CHANNEL_0,
+                TextureSwizzle::CHANNEL_1,
+                TextureSwizzle::CHANNEL_2,
+                TextureSwizzle::CHANNEL_3
+        };
    };

    // A sampler descriptor for ES2
    struct SamplerGLES2 {
-        TextureHandle handle;                   // 4
+        uint16_t target;                        // 2 (GLenum)
+        bool external = false;                  // 1
+        bool reserved = false;                  // 1
+        GLuint id = 0;                          // 4
        SamplerParams params{};                 // 4
        float anisotropy = 1.0f;                // 4
    };
@@ -138,8 +165,9 @@ private:
    };
    static_assert(sizeof(Descriptor) <= 32);

+    template<typename T>
    static void updateTextureView(OpenGLContext& gl,
-            HandleAllocatorGL& handleAllocator, GLuint unit, GLTexture const* t) noexcept;
+            HandleAllocatorGL& handleAllocator, GLuint unit, T const& desc) noexcept;

    utils::FixedCapacityVector<Descriptor> descriptors;     // 16
    utils::bitset64 dynamicBuffers;                         // 8
@@ -18,7 +18,6 @@

 #include "private/backend/Driver.h"

-#include <utils/Logger.h>
 #include <utils/compiler.h>
 #include <utils/ostream.h>
 #include <utils/trap.h>
@@ -26,7 +25,6 @@
 #include <string_view>

 #include <stddef.h>
-#include <cstdio>

 namespace filament::backend {

@@ -57,21 +55,19 @@ std::string_view getGLErrorString(GLenum error) noexcept {
 }

 UTILS_NOINLINE
-GLenum checkGLError(const char* function, size_t line) noexcept {
+GLenum checkGLError(io::ostream& out, const char* function, size_t line) noexcept {
    GLenum const error = glGetError();
    if (UTILS_VERY_UNLIKELY(error != GL_NO_ERROR)) {
        auto const string = getGLErrorString(error);
-        char hexError[16];
-        snprintf(hexError, sizeof(hexError), "%#x", error);
-        LOG(ERROR) << "OpenGL error " << hexError << " (" << string << ") in \"" << function
-                   << "\" at line " << line;
+        out << "OpenGL error " << io::hex << error << " (" << string << ") in \""
+            << function << "\" at line " << io::dec << line << io::endl;
    }
    return error;
 }

 UTILS_NOINLINE
-void assertGLError(const char* function, size_t line) noexcept {
-    GLenum const err = checkGLError(function, line);
+void assertGLError(io::ostream& out, const char* function, size_t line) noexcept {
+    GLenum const err = checkGLError(out, function, line);
    if (UTILS_VERY_UNLIKELY(err != GL_NO_ERROR)) {
        debug_trap();
    }
@@ -101,21 +97,19 @@ std::string_view getFramebufferStatusString(GLenum status) noexcept {
 }

 UTILS_NOINLINE
-GLenum checkFramebufferStatus(GLenum target, const char* function, size_t line) noexcept {
+GLenum checkFramebufferStatus(io::ostream& out, GLenum target, const char* function, size_t line) noexcept {
    GLenum const status = glCheckFramebufferStatus(target);
    if (UTILS_VERY_UNLIKELY(status != GL_FRAMEBUFFER_COMPLETE)) {
        auto const string = getFramebufferStatusString(status);
-        char hexStatus[16];
-        snprintf(hexStatus, sizeof(hexStatus), "%#x", status);
-        LOG(ERROR) << "OpenGL framebuffer error " << hexStatus << " (" << string << ") in \""
-                   << function << "\" at line " << line;
+        out << "OpenGL framebuffer error " << io::hex << status << " (" << string << ") in \""
+            << function << "\" at line " << io::dec << line << io::endl;
    }
    return status;
 }

 UTILS_NOINLINE
-void assertFramebufferStatus(GLenum target, const char* function, size_t line) noexcept {
-    GLenum const status = checkFramebufferStatus(target, function, line);
+void assertFramebufferStatus(io::ostream& out, GLenum target, const char* function, size_t line) noexcept {
+    GLenum const status = checkFramebufferStatus(out, target, function, line);
    if (UTILS_VERY_UNLIKELY(status != GL_FRAMEBUFFER_COMPLETE)) {
        debug_trap();
    }
@@ -33,21 +33,21 @@
 namespace filament::backend::GLUtils {

 std::string_view getGLErrorString(GLenum error) noexcept;
-GLenum checkGLError(const char* function, size_t line) noexcept;
-void assertGLError(const char* function, size_t line) noexcept;
+GLenum checkGLError(utils::io::ostream& out, const char* function, size_t line) noexcept;
+void assertGLError(utils::io::ostream& out, const char* function, size_t line) noexcept;

 std::string_view getFramebufferStatusString(GLenum err) noexcept;
-GLenum checkFramebufferStatus(GLenum target, const char* function, size_t line) noexcept;
-void assertFramebufferStatus(GLenum target, const char* function, size_t line) noexcept;
+GLenum checkFramebufferStatus(utils::io::ostream& out, GLenum target, const char* function, size_t line) noexcept;
+void assertFramebufferStatus(utils::io::ostream& out, GLenum target, const char* function, size_t line) noexcept;

 #ifdef NDEBUG
-#   define CHECK_GL_ERROR()
-#   define CHECK_GL_ERROR_NON_FATAL()
-#   define CHECK_GL_FRAMEBUFFER_STATUS(target)
+#   define CHECK_GL_ERROR(out)
+#   define CHECK_GL_ERROR_NON_FATAL(out)
+#   define CHECK_GL_FRAMEBUFFER_STATUS(out, target)
 #else
-#   define CHECK_GL_ERROR() { GLUtils::assertGLError(__func__, __LINE__); }
-#   define CHECK_GL_ERROR_NON_FATAL() { GLUtils::checkGLError(__func__, __LINE__); }
-#   define CHECK_GL_FRAMEBUFFER_STATUS(target) { GLUtils::checkFramebufferStatus( target, __func__, __LINE__); }
+#   define CHECK_GL_ERROR(out) { GLUtils::assertGLError(out, __func__, __LINE__); }
+#   define CHECK_GL_ERROR_NON_FATAL(out) { GLUtils::checkGLError(out, __func__, __LINE__); }
+#   define CHECK_GL_FRAMEBUFFER_STATUS(out, target) { GLUtils::checkFramebufferStatus(out, target, __func__, __LINE__); }
 #endif

 constexpr GLuint getComponentCount(ElementType const type) noexcept {
@@ -21,7 +21,7 @@
 #include <backend/Platform.h>
 #include <backend/Program.h>

-#include <private/utils/Tracing.h>
+#include <utils/Systrace.h>

 namespace filament::backend {

@@ -36,7 +36,7 @@ OpenGLBlobCache::OpenGLBlobCache(OpenGLContext& gl) noexcept

 GLuint OpenGLBlobCache::retrieve(BlobCacheKey* outKey, Platform& platform,
        Program const& program) const noexcept {
-    FILAMENT_TRACING_CALL(FILAMENT_TRACING_CATEGORY_FILAMENT);
+    SYSTRACE_CALL();
    if (!mCachingSupported || !platform.hasRetrieveBlobFunc()) {
        // the key is never updated in that case
        return 0;
@@ -68,7 +68,7 @@ GLuint OpenGLBlobCache::retrieve(BlobCacheKey* outKey, Platform& platform,
        programId = glCreateProgram();

        { // scope for systrace
-            FILAMENT_TRACING_NAME(FILAMENT_TRACING_CATEGORY_FILAMENT, "glProgramBinary");
+            SYSTRACE_NAME("glProgramBinary");
            glProgramBinary(programId, blob->format, blob->data, programBinarySize);
        }

@@ -90,7 +90,7 @@ GLuint OpenGLBlobCache::retrieve(BlobCacheKey* outKey, Platform& platform,

 void OpenGLBlobCache::insert(Platform& platform,
        BlobCacheKey const& key, GLuint program) noexcept {
-    FILAMENT_TRACING_CALL(FILAMENT_TRACING_CATEGORY_FILAMENT);
+    SYSTRACE_CALL();
    if (!mCachingSupported || !platform.hasInsertBlobFunc()) {
        // the key is never updated in that case
        return;
@@ -100,7 +100,7 @@ void OpenGLBlobCache::insert(Platform& platform,
    GLenum format;
    GLint programBinarySize = 0;
    { // scope for systrace
-        FILAMENT_TRACING_NAME(FILAMENT_TRACING_CATEGORY_FILAMENT, "glGetProgramiv");
+        SYSTRACE_NAME("glGetProgramiv");
        glGetProgramiv(program, GL_PROGRAM_BINARY_LENGTH, &programBinarySize);
    }
    if (programBinarySize) {
@@ -108,7 +108,7 @@ void OpenGLBlobCache::insert(Platform& platform,
        std::unique_ptr<Blob, decltype(&::free)> blob{ (Blob*)malloc(size), &::free };
        if (UTILS_LIKELY(blob)) {
            { // scope for systrace
-                FILAMENT_TRACING_NAME(FILAMENT_TRACING_CATEGORY_FILAMENT, "glGetProgramBinary");
+                SYSTRACE_NAME("glGetProgramBinary");
                glGetProgramBinary(program, programBinarySize,
                        &programBinarySize, &format, blob->data);
            }
@@ -22,9 +22,9 @@
 #include <backend/platforms/OpenGLPlatform.h>
 #include <backend/DriverEnums.h>

-#include <utils/Logger.h>
 #include <utils/compiler.h>
 #include <utils/debug.h>
+#include <utils/Log.h>
 #include <utils/ostream.h>

 #include <functional>
@@ -77,8 +77,8 @@ OpenGLContext::OpenGLContext(OpenGLPlatform& platform,
    state.version  = (char const*)glGetString(GL_VERSION);
    state.shader   = (char const*)glGetString(GL_SHADING_LANGUAGE_VERSION);

-    LOG(INFO) << "[" << state.vendor << "], [" << state.renderer << "], "
-                 "[" << state.version << "], [" << state.shader << "]";
+    slog.v << "[" << state.vendor << "], [" << state.renderer << "], "
+              "[" << state.version << "], [" << state.shader << "]" << io::endl;

    /*
     * Figure out GL / GLES version, extensions and capabilities we need to
@@ -164,33 +164,51 @@ OpenGLContext::OpenGLContext(OpenGLPlatform& platform,
    }
 #endif

-    LOG(INFO) << "Feature level: " << +mFeatureLevel;
-    LOG(INFO) << "Active workarounds: ";
+    slog.v << "Feature level: " << +mFeatureLevel << '\n';
+    slog.v << "Active workarounds: " << '\n';
    UTILS_NOUNROLL
    for (auto [enabled, name, _] : mBugDatabase) {
        if (enabled) {
-            LOG(INFO) << name;
+            slog.v << name << '\n';
        }
    }
+    flush(slog.v);

 #ifndef NDEBUG
    // this is useful for development
-    LOG(INFO) << "GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT = " << gets.max_anisotropy;
-    LOG(INFO) << "GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS = " << gets.max_combined_texture_image_units;
-    LOG(INFO) << "GL_MAX_TEXTURE_SIZE = " << gets.max_texture_size;
-    LOG(INFO) << "GL_MAX_CUBE_MAP_TEXTURE_SIZE = " << gets.max_cubemap_texture_size;
-    LOG(INFO) << "GL_MAX_3D_TEXTURE_SIZE = " << gets.max_3d_texture_size;
-    LOG(INFO) << "GL_MAX_ARRAY_TEXTURE_LAYERS = " << gets.max_array_texture_layers;
-    LOG(INFO) << "GL_MAX_DRAW_BUFFERS = " << gets.max_draw_buffers;
-    LOG(INFO) << "GL_MAX_RENDERBUFFER_SIZE = " << gets.max_renderbuffer_size;
-    LOG(INFO) << "GL_MAX_SAMPLES = " << gets.max_samples;
-    LOG(INFO) << "GL_MAX_TEXTURE_IMAGE_UNITS = " << gets.max_texture_image_units;
-    LOG(INFO) << "GL_MAX_TRANSFORM_FEEDBACK_SEPARATE_ATTRIBS = "
-              << gets.max_transform_feedback_separate_attribs;
-    LOG(INFO) << "GL_MAX_UNIFORM_BLOCK_SIZE = " << gets.max_uniform_block_size;
-    LOG(INFO) << "GL_MAX_UNIFORM_BUFFER_BINDINGS = " << gets.max_uniform_buffer_bindings;
-    LOG(INFO) << "GL_NUM_PROGRAM_BINARY_FORMATS = " << gets.num_program_binary_formats;
-    LOG(INFO) << "GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT = " << gets.uniform_buffer_offset_alignment;
+    slog.v
+            << "GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT = "
+                    << gets.max_anisotropy << '\n'
+            << "GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS = "
+                    << gets.max_combined_texture_image_units << '\n'
+            << "GL_MAX_TEXTURE_SIZE = "
+                    << gets.max_texture_size << '\n'
+            << "GL_MAX_CUBE_MAP_TEXTURE_SIZE = "
+                    << gets.max_cubemap_texture_size << '\n'
+            << "GL_MAX_3D_TEXTURE_SIZE = "
+                    << gets.max_3d_texture_size << '\n'
+            << "GL_MAX_ARRAY_TEXTURE_LAYERS = "
+                    << gets.max_array_texture_layers << '\n'
+            << "GL_MAX_DRAW_BUFFERS = "
+                    << gets.max_draw_buffers << '\n'
+            << "GL_MAX_RENDERBUFFER_SIZE = "
+                    << gets.max_renderbuffer_size << '\n'
+            << "GL_MAX_SAMPLES = "
+                    << gets.max_samples << '\n'
+            << "GL_MAX_TEXTURE_IMAGE_UNITS = "
+                    << gets.max_texture_image_units << '\n'
+            << "GL_MAX_TRANSFORM_FEEDBACK_SEPARATE_ATTRIBS = "
+                    << gets.max_transform_feedback_separate_attribs << '\n'
+            << "GL_MAX_UNIFORM_BLOCK_SIZE = "
+                    << gets.max_uniform_block_size << '\n'
+            << "GL_MAX_UNIFORM_BUFFER_BINDINGS = "
+                    << gets.max_uniform_buffer_bindings << '\n'
+            << "GL_NUM_PROGRAM_BINARY_FORMATS = "
+                    << gets.num_program_binary_formats << '\n'
+            << "GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT = "
+                    << gets.uniform_buffer_offset_alignment << '\n'
+            ;
+    flush(slog.v);
 #endif

 #ifndef FILAMENT_SILENCE_NOT_SUPPORTED_BY_ES2
@@ -224,14 +242,15 @@ OpenGLContext::OpenGLContext(OpenGLPlatform& platform,
    if (ext.KHR_debug) {
        auto cb = +[](GLenum, GLenum type, GLuint, GLenum severity, GLsizei length,
                const GLchar* message, const void *) {
-            auto logSeverity = utils::LogSeverity::kInfo;
+            io::ostream* stream = &slog.i;
            switch (severity) {
-                case GL_DEBUG_SEVERITY_HIGH:    logSeverity = utils::LogSeverity::kError;   break;
-                case GL_DEBUG_SEVERITY_MEDIUM:  logSeverity = utils::LogSeverity::kWarning; break;
-                case GL_DEBUG_SEVERITY_LOW:     logSeverity = utils::LogSeverity::kInfo;    break;
+                case GL_DEBUG_SEVERITY_HIGH:    stream = &slog.e;   break;
+                case GL_DEBUG_SEVERITY_MEDIUM:  stream = &slog.w;   break;
+                case GL_DEBUG_SEVERITY_LOW:     stream = &slog.d;   break;
                case GL_DEBUG_SEVERITY_NOTIFICATION:
                default: break;
            }
+            io::ostream& out = *stream;
            const char* level = ": ";
            switch (type) {
                case GL_DEBUG_TYPE_ERROR:               level = "ERROR: ";               break;
@@ -243,7 +262,7 @@ OpenGLContext::OpenGLContext(OpenGLPlatform& platform,
                case GL_DEBUG_TYPE_MARKER:              level = "MARKER: ";              break;
                default: break;
            }
-            LOG(LEVEL(logSeverity)) << "KHR_debug " << level << std::string_view{ message, size_t(length) };
+            out << "KHR_debug " << level << std::string_view{ message, size_t(length) } << io::endl;
        };
        glEnable(GL_DEBUG_OUTPUT);
        glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
@@ -523,13 +542,6 @@ void OpenGLContext::initBugs(Bugs* bugs, Extensions const& exts,
        } else if (strstr(renderer, "Intel")) {
            // Intel GPU
            bugs->vao_doesnt_store_element_array_buffer_binding = true;
-
-            if (strstr(renderer, "Mesa")) {
-                // Mesa Intel driver on Linux/Android
-                // Renderer of the form [Mesa Intel(R) HD Graphics 505 (APL 3)]
-                // b/405252622
-                bugs->disable_invalidate_framebuffer = true;
-            }
        } else if (strstr(renderer, "PowerVR")) {
            // PowerVR GPU
            // On PowerVR (Rogue GE8320) glFlush doesn't seem to do anything, in particular,
@@ -688,8 +700,9 @@ void OpenGLContext::initExtensionsGLES(Extensions* ext, GLint major, GLint minor
    GLUtils::unordered_string_set const exts = GLUtils::split(extensions);
    if constexpr (DEBUG_PRINT_EXTENSIONS) {
        for (auto extension: exts) {
-            DLOG(INFO) << "\"" << std::string_view(extension) << "\"";
+            slog.d << "\"" << std::string_view(extension) << "\"\n";
        }
+        flush(slog.d);
    }

    // figure out and initialize the extensions we need
@@ -763,8 +776,9 @@ void OpenGLContext::initExtensionsGL(Extensions* ext, GLint major, GLint minor)
    }
    if constexpr (DEBUG_PRINT_EXTENSIONS) {
        for (auto extension: exts) {
-            DLOG(INFO) << "\"" << std::string_view(extension) << "\"";
+            slog.d << "\"" << std::string_view(extension) << "\"\n";
        }
+        flush(slog.d);
    }

    using namespace std::literals;
@@ -1024,7 +1038,7 @@ GLuint OpenGLContext::getSamplerSlow(SamplerParams params) const noexcept {
                std::min(gets.max_anisotropy, anisotropy));
    }
 #endif
-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
    mSamplerMap[params] = s;
    return s;
 }
@@ -44,17 +44,15 @@
 #include "private/backend/Dispatcher.h"
 #include "private/backend/DriverApi.h"

-#include <private/utils/Tracing.h>
-
 #include <type_traits>
 #include <utils/BitmaskEnum.h>
-#include <utils/CString.h>
 #include <utils/FixedCapacityVector.h>
+#include <utils/CString.h>
 #include <utils/Invocable.h>
-#include <utils/Logger.h>
+#include <utils/Log.h>
 #include <utils/Panic.h>
-#include <utils/Slice.h>
 #include <utils/Systrace.h>
+#include <utils/Slice.h>
 #include <utils/compiler.h>
 #include <utils/debug.h>
 #include <utils/ostream.h>
@@ -100,13 +98,13 @@

 #define DEBUG_GROUP_MARKER_NONE       0x00    // no debug marker
 #define DEBUG_GROUP_MARKER_OPENGL     0x01    // markers in the gl command queue (req. driver support)
-#define DEBUG_GROUP_MARKER_BACKEND    0x02    // markers on the backend side (perfetto)
+#define DEBUG_GROUP_MARKER_BACKEND    0x02    // markers on the backend side (systrace)
 #define DEBUG_GROUP_MARKER_ALL        0xFF    // all markers

 #define DEBUG_MARKER_NONE             0x00    // no debug marker
 #define DEBUG_MARKER_OPENGL           0x01    // markers in the gl command queue (req. driver support)
-#define DEBUG_MARKER_BACKEND          0x02    // markers on the backend side (perfetto)
-#define DEBUG_MARKER_PROFILE          0x04    // profiling on the backend side (perfetto)
+#define DEBUG_MARKER_BACKEND          0x02    // markers on the backend side (systrace)
+#define DEBUG_MARKER_PROFILE          0x04    // profiling on the backend side (systrace)
 #define DEBUG_MARKER_ALL              (0xFF & ~DEBUG_MARKER_PROFILE) // all markers

 // set to the desired debug marker level (for user markers [default: All])
@@ -185,18 +183,20 @@ OpenGLDriver* OpenGLDriver::create(OpenGLPlatform* platform,
    //    GLVertexBufferInfo        : 132       moderate
    // -- less than or equal to 136 bytes

-    DLOG(INFO) << "GLSwapChain: " << sizeof(GLSwapChain);
-    DLOG(INFO) << "GLBufferObject: " << sizeof(GLBufferObject);
-    DLOG(INFO) << "GLVertexBuffer: " << sizeof(GLVertexBuffer);
-    DLOG(INFO) << "GLVertexBufferInfo: " << sizeof(GLVertexBufferInfo);
-    DLOG(INFO) << "GLIndexBuffer: " << sizeof(GLIndexBuffer);
-    DLOG(INFO) << "GLRenderPrimitive: " << sizeof(GLRenderPrimitive);
-    DLOG(INFO) << "GLTexture: " << sizeof(GLTexture);
-    DLOG(INFO) << "GLTimerQuery: " << sizeof(GLTimerQuery);
-    DLOG(INFO) << "GLStream: " << sizeof(GLStream);
-    DLOG(INFO) << "GLRenderTarget: " << sizeof(GLRenderTarget);
-    DLOG(INFO) << "GLFence: " << sizeof(GLFence);
-    DLOG(INFO) << "OpenGLProgram: " << sizeof(OpenGLProgram);
+    slog.d
+           << "\nGLSwapChain: " << sizeof(GLSwapChain)
+           << "\nGLBufferObject: " << sizeof(GLBufferObject)
+           << "\nGLVertexBuffer: " << sizeof(GLVertexBuffer)
+           << "\nGLVertexBufferInfo: " << sizeof(GLVertexBufferInfo)
+           << "\nGLIndexBuffer: " << sizeof(GLIndexBuffer)
+           << "\nGLRenderPrimitive: " << sizeof(GLRenderPrimitive)
+           << "\nGLTexture: " << sizeof(GLTexture)
+           << "\nGLTimerQuery: " << sizeof(GLTimerQuery)
+           << "\nGLStream: " << sizeof(GLStream)
+           << "\nGLRenderTarget: " << sizeof(GLRenderTarget)
+           << "\nGLFence: " << sizeof(GLFence)
+           << "\nOpenGLProgram: " << sizeof(OpenGLProgram)
+           << io::endl;
 #endif

    // here we check we're on a supported version of GL before initializing the driver
@@ -248,8 +248,8 @@ OpenGLDriver::DebugMarker::DebugMarker(OpenGLDriver& driver, const char* string)
 #endif

 #if DEBUG_MARKER_LEVEL & DEBUG_MARKER_BACKEND
-    FILAMENT_TRACING_CONTEXT(FILAMENT_TRACING_CATEGORY_FILAMENT);
-    FILAMENT_TRACING_NAME_BEGIN(FILAMENT_TRACING_CATEGORY_FILAMENT, string);
+    SYSTRACE_CONTEXT();
+    SYSTRACE_NAME_BEGIN(string);
 #endif
 #endif
 }
@@ -265,8 +265,8 @@ OpenGLDriver::DebugMarker::~DebugMarker() noexcept {
 #endif

 #if DEBUG_MARKER_LEVEL & DEBUG_MARKER_BACKEND
-    FILAMENT_TRACING_CONTEXT(FILAMENT_TRACING_CATEGORY_FILAMENT);
-    FILAMENT_TRACING_NAME_END(FILAMENT_TRACING_CATEGORY_FILAMENT);
+    SYSTRACE_CONTEXT();
+    SYSTRACE_NAME_END();
 #endif
 #endif
 }
@@ -288,7 +288,7 @@ OpenGLDriver::OpenGLDriver(OpenGLPlatform* platform, const Platform::DriverConfi
    mStreamsWithPendingAcquiredImage.reserve(8);

 #ifndef NDEBUG
-    LOG(INFO) << "OS version: " << mPlatform.getOSVersion();
+    slog.i << "OS version: " << mPlatform.getOSVersion() << io::endl;
 #endif

    // Timer queries are core in GL 3.3, otherwise we need EXT_disjoint_timer_query
@@ -667,7 +667,7 @@ void OpenGLDriver::createIndexBufferR(
    gl.bindVertexArray(nullptr);
    gl.bindBuffer(GL_ELEMENT_ARRAY_BUFFER, ib->gl.buffer);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, size, nullptr, getBufferUsage(usage));
-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::createBufferObjectR(Handle<HwBufferObject> boh,
@@ -692,7 +692,7 @@ void OpenGLDriver::createBufferObjectR(Handle<HwBufferObject> boh,
        glBufferData(bo->gl.binding, byteCount, nullptr, getBufferUsage(usage));
    }

-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::createRenderPrimitiveR(Handle<HwRenderPrimitive> rph,
@@ -729,7 +729,7 @@ void OpenGLDriver::createRenderPrimitiveR(Handle<HwRenderPrimitive> rph,
    // this records the index buffer into the currently bound VAO
    gl.bindBuffer(GL_ELEMENT_ARRAY_BUFFER, ib->gl.buffer);

-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::createProgramR(Handle<HwProgram> ph, Program&& program) {
@@ -759,7 +759,7 @@ void OpenGLDriver::createProgramR(Handle<HwProgram> ph, Program&& program) {
    }

    construct<OpenGLProgram>(ph, *this, std::move(program));
-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 UTILS_NOINLINE
@@ -931,12 +931,7 @@ void OpenGLDriver::createTextureR(Handle<HwTexture> th, SamplerType target, uint
 #if defined(BACKEND_OPENGL_LEVEL_GLES31)
                if (gl.features.multisample_texture) {
                    // multi-sample texture on GL 3.2 / GLES 3.1 and above
-                    if (depth <= 1) {
-                        // We forcibly change the target to 2D-multisample only for flat texture.
-                        // A depth value greater than 1 may indicate multiview usage, which requires
-                        // GL_TEXTURE_2D_ARRAY. Also 2D MSAA won't work with non-flat texture anyway.
-                        t->gl.target = GL_TEXTURE_2D_MULTISAMPLE;
-                    }
+                    t->gl.target = GL_TEXTURE_2D_MULTISAMPLE;
                } else {
                    // Turn off multi-sampling for that texture. It's just not supported.
                }
@@ -952,7 +947,7 @@ void OpenGLDriver::createTextureR(Handle<HwTexture> th, SamplerType target, uint
        renderBufferStorage(t->gl.id, internalFormat, w, h, samples);
    }

-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::createTextureViewR(Handle<HwTexture> th,
@@ -998,7 +993,7 @@ void OpenGLDriver::createTextureViewR(Handle<HwTexture> th,
    assert_invariant(ref);
    ref->count++;

-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::createTextureViewSwizzleR(Handle<HwTexture> th, Handle<HwTexture> srch,
@@ -1061,7 +1056,7 @@ void OpenGLDriver::createTextureViewSwizzleR(Handle<HwTexture> th, Handle<HwText
    assert_invariant(ref);
    ref->count++;

-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::createTextureExternalImage2R(Handle<HwTexture> th, SamplerType target,
@@ -1212,19 +1207,14 @@ void OpenGLDriver::importTextureR(Handle<HwTexture> th, intptr_t id,
 #if defined(BACKEND_OPENGL_LEVEL_GLES31)
        if (gl.features.multisample_texture) {
            // multi-sample texture on GL 3.2 / GLES 3.1 and above
-            if (depth <= 1) {
-                // We forcibly change the target to 2D-multisample only for flat texture.
-                // A depth value greater than 1 may indicate multiview usage, which requires
-                // GL_TEXTURE_2D_ARRAY. Also 2D MSAA won't work with non-flat texture anyway.
-                t->gl.target = GL_TEXTURE_2D_MULTISAMPLE;
-            }
+            t->gl.target = GL_TEXTURE_2D_MULTISAMPLE;
        } else {
            // Turn off multi-sampling for that texture. It's just not supported.
        }
 #endif
    }

-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::updateVertexArrayObject(GLRenderPrimitive* rp, GLVertexBuffer const* vb) {
@@ -1462,15 +1452,8 @@ void OpenGLDriver::framebufferTexture(TargetBufferInfo const& binfo,
 #if !defined(__EMSCRIPTEN__) && !defined(FILAMENT_IOS)
                if (layerCount > 1) {
                    // if layerCount > 1, it means we use the multiview extension.
-                    if (rt->gl.samples > 1) {
-                        // For MSAA
-                        glFramebufferTextureMultisampleMultiviewOVR(GL_FRAMEBUFFER, attachment,
-                                t->gl.id, 0, rt->gl.samples, binfo.layer, layerCount);
-                    }
-                    else {
-                        glFramebufferTextureMultiviewOVR(GL_FRAMEBUFFER, attachment, t->gl.id, 0,
-                                binfo.layer, layerCount);
-                    }
+                    glFramebufferTextureMultiviewOVR(GL_FRAMEBUFFER, attachment,
+                        t->gl.id, 0, binfo.layer, layerCount);
                } else
 #endif // !defined(__EMSCRIPTEN__) && !defined(FILAMENT_IOS)
                {
@@ -1484,7 +1467,7 @@ void OpenGLDriver::framebufferTexture(TargetBufferInfo const& binfo,
                // we shouldn't be here
                break;
        }
-        CHECK_GL_ERROR()
+        CHECK_GL_ERROR(utils::slog.e)
    } else
 #ifndef __EMSCRIPTEN__
 #ifdef GL_EXT_multisampled_render_to_texture
@@ -1505,7 +1488,7 @@ void OpenGLDriver::framebufferTexture(TargetBufferInfo const& binfo,
            glFramebufferRenderbuffer(GL_FRAMEBUFFER, attachment,
                    GL_RENDERBUFFER, t->gl.id);
        }
-        CHECK_GL_ERROR()
+        CHECK_GL_ERROR(utils::slog.e)
    } else
 #endif // GL_EXT_multisampled_render_to_texture
 #endif // __EMSCRIPTEN__
@@ -1587,13 +1570,13 @@ void OpenGLDriver::framebufferTexture(TargetBufferInfo const& binfo,
                break;
        }

-        CHECK_GL_ERROR()
+        CHECK_GL_ERROR(utils::slog.e)
    }

    rt->gl.resolve |= resolveFlags;

-    CHECK_GL_ERROR()
-    CHECK_GL_FRAMEBUFFER_STATUS(GL_FRAMEBUFFER)
+    CHECK_GL_ERROR(utils::slog.e)
+    CHECK_GL_FRAMEBUFFER_STATUS(utils::slog.e, GL_FRAMEBUFFER)
 }

 void OpenGLDriver::renderBufferStorage(GLuint rbo, GLenum internalformat, uint32_t width, // NOLINT(readability-convert-member-functions-to-static)
@@ -1622,7 +1605,7 @@ void OpenGLDriver::renderBufferStorage(GLuint rbo, GLenum internalformat, uint32
    // unbind the renderbuffer, to avoid any later confusion
    glBindRenderbuffer(GL_RENDERBUFFER, 0);

-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::createDefaultRenderTargetR(
@@ -1719,7 +1702,7 @@ void OpenGLDriver::createRenderTargetR(Handle<HwRenderTarget> rth,
        if (UTILS_LIKELY(!getContext().isES2())) {
            glDrawBuffers((GLsizei)maxDrawBuffers, bufs);
        }
-        CHECK_GL_ERROR()
+        CHECK_GL_ERROR(utils::slog.e)
    }
 #endif

@@ -1759,7 +1742,7 @@ void OpenGLDriver::createRenderTargetR(Handle<HwRenderTarget> rth,
    assert_invariant(any(targets & TargetBufferFlags::ALL));
    assert_invariant(tmin == tmax);

-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::createFenceR(Handle<HwFence> fh, int) {
@@ -2110,7 +2093,7 @@ void OpenGLDriver::setAcquiredImage(Handle<HwStream> sh, void* hwbuffer, const m

    if (UTILS_UNLIKELY(glstream->user_thread.pending.image)) {
        scheduleRelease(glstream->user_thread.pending);
-        LOG(WARNING) << "Acquired image is set more than once per frame.";
+        slog.w << "Acquired image is set more than once per frame." << io::endl;
    }

    glstream->user_thread.pending = mPlatform.transformAcquiredImage({
@@ -2530,36 +2513,13 @@ void OpenGLDriver::makeCurrent(Handle<HwSwapChain> schDraw, Handle<HwSwapChain>

    mPlatform.makeCurrent(scDraw->swapChain, scRead->swapChain,
            [this]() {
-                for (auto t: mTexturesWithStreamsAttached) {
-                    if (t->hwStream->streamType == StreamType::NATIVE) {
-                        mPlatform.detach(t->hwStream->stream);
-                    }
-                }
                // OpenGL context is about to change, unbind everything
                mContext.unbindEverything();
            },
            [this](size_t index) {
-                for (auto t: mTexturesWithStreamsAttached) {
-                    if (t->hwStream->streamType == StreamType::NATIVE) {
-                        if (t->externalTexture) {
-                            glGenTextures(1, &t->externalTexture->id);
-                            t->gl.id = t->externalTexture->id;
-                        } else {
-                            glGenTextures(1, &t->gl.id);
-                        }
-                        mPlatform.attach(t->hwStream->stream, t->gl.id);
-                        mContext.updateTexImage(GL_TEXTURE_EXTERNAL_OES, t->gl.id);
-                    }
-                }
-
-                // force invalidation of all bound descriptor sets
-                decltype(mInvalidDescriptorSetBindings) changed;
-                changed.setValue((1 << MAX_DESCRIPTOR_SET_COUNT) - 1);
-                mInvalidDescriptorSetBindings |= changed;
-
                // OpenGL context has changed, resynchronize the state with the cache
                mContext.synchronizeStateAndCache(index);
-                DLOG(INFO) << "*** OpenGL context change : " << (index ? "protected" : "default");
+                slog.d << "*** OpenGL context change : " << (index ? "protected" : "default") << io::endl;
            });

    mCurrentDrawSwapChain = scDraw;
@@ -2600,7 +2560,7 @@ void OpenGLDriver::setVertexBufferObject(Handle<HwVertexBuffer> vbh,
        vb->bufferObjectsVersion = (version + 1) % kMaxVersion;
    }

-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::updateIndexBuffer(
@@ -2617,7 +2577,7 @@ void OpenGLDriver::updateIndexBuffer(

    scheduleDestroy(std::move(p));

-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::registerBufferObjectStreams(Handle<HwBufferObject> boh, BufferObjectStreamDescriptor&& streams) {
@@ -2697,7 +2657,7 @@ void OpenGLDriver::updateBufferObject(

    scheduleDestroy(std::move(bd));

-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::updateBufferObjectUnsynchronized(
@@ -2744,7 +2704,7 @@ retry:
            scheduleDestroy(std::move(bd));
        }
    }
-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 #endif
 }

@@ -2794,7 +2754,7 @@ void OpenGLDriver::generateMipmaps(Handle<HwTexture> th) {

    glGenerateMipmap(t->gl.target);

-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::setTextureData(GLTexture const* t, uint32_t level,
@@ -2903,7 +2863,7 @@ void OpenGLDriver::setTextureData(GLTexture const* t, uint32_t level,

    scheduleDestroy(std::move(p));

-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::setCompressedTextureData(GLTexture const* t, uint32_t level,
@@ -2989,7 +2949,7 @@ void OpenGLDriver::setCompressedTextureData(GLTexture const* t, uint32_t level,

    scheduleDestroy(std::move(p));

-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::setupExternalImage2(Platform::ExternalImageHandleRef image) {
@@ -3031,7 +2991,6 @@ void OpenGLDriver::attachStream(GLTexture* t, GLStream* hwStream) noexcept {
    switch (hwStream->streamType) {
        case StreamType::NATIVE:
            mPlatform.attach(hwStream->stream, t->gl.id);
-            mContext.updateTexImage(GL_TEXTURE_EXTERNAL_OES, t->gl.id);
            break;
        case StreamType::ACQUIRED:
            break;
@@ -3060,12 +3019,7 @@ void OpenGLDriver::detachStream(GLTexture* t) noexcept {
            break;
    }

-    if (t->externalTexture) {
-        glGenTextures(1, &t->externalTexture->id);
-        t->gl.id = t->externalTexture->id;
-    } else {
-        glGenTextures(1, &t->gl.id);
-    }
+    glGenTextures(1, &t->gl.id);

    t->hwStream = nullptr;
 }
@@ -3089,14 +3043,8 @@ void OpenGLDriver::replaceStream(GLTexture* texture, GLStream* newStream) noexce

    switch (newStream->streamType) {
        case StreamType::NATIVE:
-            if (texture->externalTexture) {
-                glGenTextures(1, &texture->externalTexture->id);
-                texture->gl.id = texture->externalTexture->id;
-            } else {
-                glGenTextures(1, &texture->gl.id);
-            }
+            glGenTextures(1, &texture->gl.id);
            mPlatform.attach(newStream->stream, texture->gl.id);
-            mContext.updateTexImage(GL_TEXTURE_EXTERNAL_OES, texture->gl.id);
            break;
        case StreamType::ACQUIRED:
            // Just re-use the old texture id.
@@ -3152,7 +3100,7 @@ void OpenGLDriver::beginRenderPass(Handle<HwRenderTarget> rth,
    TargetBufferFlags discardFlags = params.flags.discardStart & rt->targets;

    GLuint const fbo = gl.bindFramebuffer(GL_FRAMEBUFFER, rt->gl.fbo);
-    CHECK_GL_FRAMEBUFFER_STATUS(GL_FRAMEBUFFER)
+    CHECK_GL_FRAMEBUFFER_STATUS(utils::slog.e, GL_FRAMEBUFFER)

    // each render-pass starts with a disabled scissor
    gl.disable(GL_SCISSOR_TEST);
@@ -3164,7 +3112,7 @@ void OpenGLDriver::beginRenderPass(Handle<HwRenderTarget> rth,
        if (attachmentCount) {
            gl.procs.invalidateFramebuffer(GL_FRAMEBUFFER, attachmentCount, attachments.data());
        }
-        CHECK_GL_ERROR()
+        CHECK_GL_ERROR(utils::slog.e)
    } else {
        // It's important to clear the framebuffer before drawing, as it resets
        // the fb to a known state (resets fb compression and possibly other things).
@@ -3251,7 +3199,7 @@ void OpenGLDriver::endRenderPass(int) {
            if (attachmentCount) {
                gl.procs.invalidateFramebuffer(GL_FRAMEBUFFER, attachmentCount, attachments.data());
            }
-           CHECK_GL_ERROR()
+           CHECK_GL_ERROR(utils::slog.e)
        }
    }

@@ -3297,13 +3245,13 @@ void OpenGLDriver::resolvePass(ResolveAction action, GLRenderTarget const* rt,
        gl.bindFramebuffer(GL_READ_FRAMEBUFFER, read);
        gl.bindFramebuffer(GL_DRAW_FRAMEBUFFER, draw);

-        CHECK_GL_FRAMEBUFFER_STATUS(GL_READ_FRAMEBUFFER)
-        CHECK_GL_FRAMEBUFFER_STATUS(GL_DRAW_FRAMEBUFFER)
+        CHECK_GL_FRAMEBUFFER_STATUS(utils::slog.e, GL_READ_FRAMEBUFFER)
+        CHECK_GL_FRAMEBUFFER_STATUS(utils::slog.e, GL_DRAW_FRAMEBUFFER)

        gl.disable(GL_SCISSOR_TEST);
        glBlitFramebuffer(0, 0, (GLint)rt->width, (GLint)rt->height,
                0, 0, (GLint)rt->width, (GLint)rt->height, mask, GL_NEAREST);
-        CHECK_GL_ERROR()
+        CHECK_GL_ERROR(utils::slog.e)
    }
 #endif
 }
@@ -3400,8 +3348,8 @@ void OpenGLDriver::pushGroupMarker(char const* string) {
 #endif

 #if DEBUG_GROUP_MARKER_LEVEL & DEBUG_GROUP_MARKER_BACKEND
-    FILAMENT_TRACING_CONTEXT(FILAMENT_TRACING_CATEGORY_FILAMENT);
-    FILAMENT_TRACING_NAME_BEGIN(FILAMENT_TRACING_CATEGORY_FILAMENT, string);
+    SYSTRACE_CONTEXT();
+    SYSTRACE_NAME_BEGIN(string);
 #endif
 #endif
 }
@@ -3417,8 +3365,8 @@ void OpenGLDriver::popGroupMarker(int) {
 #endif

 #if DEBUG_GROUP_MARKER_LEVEL & DEBUG_GROUP_MARKER_BACKEND
-    FILAMENT_TRACING_CONTEXT(FILAMENT_TRACING_CATEGORY_FILAMENT);
-    FILAMENT_TRACING_NAME_END(FILAMENT_TRACING_CATEGORY_FILAMENT);
+    SYSTRACE_CONTEXT();
+    SYSTRACE_NAME_END();
 #endif
 #endif
 }
@@ -3482,7 +3430,7 @@ void OpenGLDriver::readPixels(Handle<HwRenderTarget> src,
        if (buffer) {
            gl.bindFramebuffer(GL_FRAMEBUFFER, s->gl.fbo_read ? s->gl.fbo_read : s->gl.fbo);
            glReadPixels(GLint(x), GLint(y), GLint(width), GLint(height), glFormat, glType, buffer);
-            CHECK_GL_ERROR()
+            CHECK_GL_ERROR(utils::slog.e)

            // now we need to flip the buffer vertically to match our API
            size_t const stride = p.stride ? p.stride : width;
@@ -3514,7 +3462,7 @@ void OpenGLDriver::readPixels(Handle<HwRenderTarget> src,
    glBufferData(GL_PIXEL_PACK_BUFFER, pboSize, nullptr, GL_STATIC_DRAW);
    glReadPixels(GLint(x), GLint(y), GLint(width), GLint(height), glFormat, glType, nullptr);
    gl.bindBuffer(GL_PIXEL_PACK_BUFFER, 0);
-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)

    // we're forced to make a copy on the heap because otherwise it deletes std::function<> copy
    // constructor.
@@ -3554,7 +3502,7 @@ void OpenGLDriver::readPixels(Handle<HwRenderTarget> src,
        glDeleteBuffers(1, &pbo);
        scheduleDestroy(std::move(p));
        delete pUserBuffer;
-        CHECK_GL_ERROR()
+        CHECK_GL_ERROR(utils::slog.e)
    });
 #endif
 }
@@ -3579,7 +3527,7 @@ void OpenGLDriver::readBufferSubData(BufferObjectHandle boh,
        glCopyBufferSubData(bo->gl.binding, GL_PIXEL_PACK_BUFFER, offset, 0, size);
        gl.bindBuffer(bo->gl.binding, 0);
        gl.bindBuffer(GL_PIXEL_PACK_BUFFER, 0);
-        CHECK_GL_ERROR()
+        CHECK_GL_ERROR(utils::slog.e)

        // then, we schedule a mapBuffer of the PBO later, once the fence has signaled
        auto* pUserBuffer = new BufferDescriptor(std::move(p));
@@ -3596,7 +3544,7 @@ void OpenGLDriver::readBufferSubData(BufferObjectHandle boh,
            glDeleteBuffers(1, &pbo);
            scheduleDestroy(std::move(p));
            delete pUserBuffer;
-            CHECK_GL_ERROR()
+            CHECK_GL_ERROR(utils::slog.e)
        });
    } else {
        gl.bindBuffer(bo->gl.binding, bo->gl.id);
@@ -3609,7 +3557,7 @@ void OpenGLDriver::readBufferSubData(BufferObjectHandle boh,
        }
        gl.bindBuffer(bo->gl.binding, 0);
        scheduleDestroy(std::move(p));
-        CHECK_GL_ERROR()
+        CHECK_GL_ERROR(utils::slog.e)
    }
 #endif
 }
@@ -3639,7 +3587,7 @@ void OpenGLDriver::whenFrameComplete(const std::function<void()>& fn) noexcept {
 void OpenGLDriver::whenGpuCommandsComplete(const std::function<void()>& fn) noexcept {
    GLsync sync = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
    mGpuCommandCompleteOps.emplace_back(sync, fn);
-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::executeGpuCommandsCompleteOps() noexcept {
@@ -3737,7 +3685,7 @@ void OpenGLDriver::endFrame(UTILS_UNUSED uint32_t frameId) {
    gl.depthFunc(GL_LESS);
    gl.disable(GL_SCISSOR_TEST);
 #endif
-    //FILAMENT_TRACING_NAME(FILAMENT_TRACING_CATEGORY_FILAMENT, "glFinish");
+    //SYSTRACE_NAME("glFinish");
    //glFinish();
    mPlatform.endFrame(frameId);
    insertEventMarker("endFrame");
@@ -3759,7 +3707,8 @@ void OpenGLDriver::updateDescriptorSetTexture(
        TextureHandle th,
        SamplerParams params) {
    GLDescriptorSet* ds = handle_cast<GLDescriptorSet*>(dsh);
-    ds->update(mContext, mHandleAllocator, binding, th, params);
+    GLTexture* t = th ? handle_cast<GLTexture*>(th) : nullptr;
+    ds->update(mContext, binding, t, params);
 }

 void OpenGLDriver::flush(int) {
@@ -3857,7 +3806,7 @@ void OpenGLDriver::clearWithRasterPipe(TargetBufferFlags clearFlags,
        }
    }

-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void OpenGLDriver::resolve(
@@ -3968,7 +3917,7 @@ void OpenGLDriver::blit(
        case SamplerType::SAMPLER_EXTERNAL:
            break;
    }
-    CHECK_GL_FRAMEBUFFER_STATUS(GL_DRAW_FRAMEBUFFER)
+    CHECK_GL_FRAMEBUFFER_STATUS(utils::slog.e, GL_DRAW_FRAMEBUFFER)

    gl.bindFramebuffer(GL_READ_FRAMEBUFFER, fbo[1]);
    switch (s->target) {
@@ -3994,14 +3943,14 @@ void OpenGLDriver::blit(
        case SamplerType::SAMPLER_EXTERNAL:
            break;
    }
-    CHECK_GL_FRAMEBUFFER_STATUS(GL_READ_FRAMEBUFFER)
+    CHECK_GL_FRAMEBUFFER_STATUS(utils::slog.e, GL_READ_FRAMEBUFFER)

    gl.disable(GL_SCISSOR_TEST);
    glBlitFramebuffer(
            srcOrigin.x, srcOrigin.y, srcOrigin.x + size.x, srcOrigin.y + size.y,
            dstOrigin.x, dstOrigin.y, dstOrigin.x + size.x, dstOrigin.y + size.y,
            mask, GL_NEAREST);
-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)

    gl.unbindFramebuffer(GL_DRAW_FRAMEBUFFER);
    gl.unbindFramebuffer(GL_READ_FRAMEBUFFER);
@@ -4064,15 +4013,15 @@ void OpenGLDriver::blitDEPRECATED(TargetBufferFlags buffers,
    gl.bindFramebuffer(GL_READ_FRAMEBUFFER, s->gl.fbo);
    gl.bindFramebuffer(GL_DRAW_FRAMEBUFFER, d->gl.fbo);

-    CHECK_GL_FRAMEBUFFER_STATUS(GL_READ_FRAMEBUFFER)
-    CHECK_GL_FRAMEBUFFER_STATUS(GL_DRAW_FRAMEBUFFER)
+    CHECK_GL_FRAMEBUFFER_STATUS(utils::slog.e, GL_READ_FRAMEBUFFER)
+    CHECK_GL_FRAMEBUFFER_STATUS(utils::slog.e, GL_DRAW_FRAMEBUFFER)

    gl.disable(GL_SCISSOR_TEST);
    glBlitFramebuffer(
            srcRect.left, srcRect.bottom, srcRect.right(), srcRect.top(),
            dstRect.left, dstRect.bottom, dstRect.right(), dstRect.top(),
            GL_COLOR_BUFFER_BIT, glFilterMode);
-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 #endif
 }

@@ -4199,9 +4148,9 @@ void OpenGLDriver::draw2(uint32_t indexOffset, uint32_t indexCount, uint32_t ins
 #endif

 #if FILAMENT_ENABLE_MATDBG
-    CHECK_GL_ERROR_NON_FATAL()
+    CHECK_GL_ERROR_NON_FATAL(utils::slog.e)
 #else
-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 #endif
 }

@@ -4231,9 +4180,9 @@ void OpenGLDriver::draw2GLES2(uint32_t indexOffset, uint32_t indexCount, uint32_
            reinterpret_cast<const void*>(indexOffset << rp->gl.indicesShift));

 #if FILAMENT_ENABLE_MATDBG
-    CHECK_GL_ERROR_NON_FATAL()
+    CHECK_GL_ERROR_NON_FATAL(utils::slog.e)
 #else
-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 #endif
 }

@@ -4283,9 +4232,9 @@ void OpenGLDriver::dispatchCompute(Handle<HwProgram> program, uint3 workGroupCou
 #endif // BACKEND_OPENGL_LEVEL_GLES31

 #if FILAMENT_ENABLE_MATDBG
-    CHECK_GL_ERROR_NON_FATAL()
+    CHECK_GL_ERROR_NON_FATAL(utils::slog.e)
 #else
-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 #endif
 }

@@ -64,7 +64,7 @@ utils::CString OpenGLPlatform::getRendererString(Driver const* driver) {
 }

 void OpenGLPlatform::makeCurrent(SwapChain* drawSwapChain, SwapChain* readSwapChain,
-        utils::Invocable<void()>, utils::Invocable<void(size_t)>) {
+        utils::Invocable<void()>, utils::Invocable<void(size_t)>) noexcept {
    makeCurrent(getCurrentContextType(), drawSwapChain, readSwapChain);
 }

@@ -25,13 +25,12 @@
 #include <backend/Program.h>
 #include <backend/Handle.h>

-#include <private/utils/Tracing.h>
-
 #include <utils/BitmaskEnum.h>
 #include <utils/compiler.h>
 #include <utils/debug.h>
 #include <utils/FixedCapacityVector.h>
 #include <utils/Log.h>
+#include <utils/Systrace.h>

 #include <algorithm>
 #include <array>
@@ -97,7 +96,8 @@ OpenGLProgram::~OpenGLProgram() noexcept {
 }

 void OpenGLProgram::initialize(OpenGLDriver& gld) {
-    FILAMENT_TRACING_CALL(FILAMENT_TRACING_CATEGORY_FILAMENT);
+
+    SYSTRACE_CALL();

    assert_invariant(gl.program == 0);
    assert_invariant(mToken);
@@ -122,7 +122,8 @@ void OpenGLProgram::initialize(OpenGLDriver& gld) {
 */
 void OpenGLProgram::initializeProgramState(OpenGLContext& context, GLuint program,
        LazyInitializationData& lazyInitializationData) noexcept {
-    FILAMENT_TRACING_CALL(FILAMENT_TRACING_CATEGORY_FILAMENT);
+
+    SYSTRACE_CALL();

    // from the pipeline layout we compute a mapping from {set, binding} to {binding}
    // for both buffers and textures
@@ -174,31 +175,7 @@ void OpenGLProgram::initializeProgramState(OpenGLContext& context, GLuint progra
                    }
                    break;
                }
-                case DescriptorType::SAMPLER_2D_FLOAT:
-                case DescriptorType::SAMPLER_2D_INT:
-                case DescriptorType::SAMPLER_2D_UINT:
-                case DescriptorType::SAMPLER_2D_DEPTH:
-                case DescriptorType::SAMPLER_2D_ARRAY_FLOAT:
-                case DescriptorType::SAMPLER_2D_ARRAY_INT:
-                case DescriptorType::SAMPLER_2D_ARRAY_UINT:
-                case DescriptorType::SAMPLER_2D_ARRAY_DEPTH:
-                case DescriptorType::SAMPLER_CUBE_FLOAT:
-                case DescriptorType::SAMPLER_CUBE_INT:
-                case DescriptorType::SAMPLER_CUBE_UINT:
-                case DescriptorType::SAMPLER_CUBE_DEPTH:
-                case DescriptorType::SAMPLER_CUBE_ARRAY_FLOAT:
-                case DescriptorType::SAMPLER_CUBE_ARRAY_INT:
-                case DescriptorType::SAMPLER_CUBE_ARRAY_UINT:
-                case DescriptorType::SAMPLER_CUBE_ARRAY_DEPTH:
-                case DescriptorType::SAMPLER_3D_FLOAT:
-                case DescriptorType::SAMPLER_3D_INT:
-                case DescriptorType::SAMPLER_3D_UINT:
-                case DescriptorType::SAMPLER_2D_MS_FLOAT:
-                case DescriptorType::SAMPLER_2D_MS_INT:
-                case DescriptorType::SAMPLER_2D_MS_UINT:
-                case DescriptorType::SAMPLER_2D_MS_ARRAY_FLOAT:
-                case DescriptorType::SAMPLER_2D_MS_ARRAY_INT:
-                case DescriptorType::SAMPLER_2D_MS_ARRAY_UINT:
+                case DescriptorType::SAMPLER:
                case DescriptorType::SAMPLER_EXTERNAL: {
                    if (!entry.name.empty()) {
                        GLint const loc = glGetUniformLocation(program, entry.name.c_str());
@@ -214,7 +191,7 @@ void OpenGLProgram::initializeProgramState(OpenGLContext& context, GLuint progra
                case DescriptorType::INPUT_ATTACHMENT:
                    break;
            }
-            CHECK_GL_ERROR()
+            CHECK_GL_ERROR(utils::slog.e)
        }
    }

@@ -23,13 +23,12 @@
 #include <backend/platforms/OpenGLPlatform.h>
 #include <backend/DriverEnums.h>

-#include <private/utils/Tracing.h>
-
 #include <utils/compiler.h>
 #include <utils/debug.h>
 #include <utils/JobSystem.h>
 #include <utils/Log.h>
 #include <utils/Mutex.h>
+#include <utils/Systrace.h>

 #include <atomic>
 #include <memory>
@@ -114,14 +113,14 @@ void TimerQueryNativeFactory::createTimerQuery(GLTimerQuery* tq) {

    tq->state = std::make_shared<GLTimerQuery::State>();
    mContext.procs.genQueries(1u, &tq->state->gl.query);
-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void TimerQueryNativeFactory::destroyTimerQuery(GLTimerQuery* tq) {
    assert_invariant(tq->state);

    mContext.procs.deleteQueries(1u, &tq->state->gl.query);
-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)

    tq->state.reset();
 }
@@ -131,14 +130,14 @@ void TimerQueryNativeFactory::beginTimeElapsedQuery(GLTimerQuery* tq) {

    tq->state->elapsed.store(int64_t(TimerQueryResult::NOT_READY), std::memory_order_relaxed);
    mContext.procs.beginQuery(GL_TIME_ELAPSED, tq->state->gl.query);
-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)
 }

 void TimerQueryNativeFactory::endTimeElapsedQuery(OpenGLDriver& driver, GLTimerQuery* tq) {
    assert_invariant(tq->state);

    mContext.procs.endQuery(GL_TIME_ELAPSED);
-    CHECK_GL_ERROR()
+    CHECK_GL_ERROR(utils::slog.e)

    std::weak_ptr<GLTimerQuery::State> const weak = tq->state;

@@ -153,7 +152,7 @@ void TimerQueryNativeFactory::endTimeElapsedQuery(OpenGLDriver& driver, GLTimerQ

        GLuint available = 0;
        context.procs.getQueryObjectuiv(state->gl.query, GL_QUERY_RESULT_AVAILABLE, &available);
-        CHECK_GL_ERROR()
+        CHECK_GL_ERROR(utils::slog.e)
        if (!available) {
            // we need to try this one again later
            return false;
@@ -241,8 +240,8 @@ void TimerQueryFenceFactory::beginTimeElapsedQuery(GLTimerQuery* tq) {
        if (state) {
            platform.waitFence(fence, FENCE_WAIT_FOR_EVER);
            state->then = clock::now().time_since_epoch().count();
-            FILAMENT_TRACING_CONTEXT(FILAMENT_TRACING_CATEGORY_FILAMENT);
-            FILAMENT_TRACING_ASYNC_BEGIN(FILAMENT_TRACING_CATEGORY_FILAMENT, "OpenGLTimerQueryFence", intptr_t(state.get()));
+            SYSTRACE_CONTEXT();
+            SYSTRACE_ASYNC_BEGIN("OpenGLTimerQueryFence", intptr_t(state.get()));
        }
        platform.destroyFence(fence);
    });
@@ -258,8 +257,8 @@ void TimerQueryFenceFactory::endTimeElapsedQuery(OpenGLDriver&, GLTimerQuery* tq
            platform.waitFence(fence, FENCE_WAIT_FOR_EVER);
            int64_t const now = clock::now().time_since_epoch().count();
            state->elapsed.store(now - state->then, std::memory_order_relaxed);
-            FILAMENT_TRACING_CONTEXT(FILAMENT_TRACING_CATEGORY_FILAMENT);
-            FILAMENT_TRACING_ASYNC_END(FILAMENT_TRACING_CATEGORY_FILAMENT, "OpenGLTimerQueryFence", intptr_t(state.get()));
+            SYSTRACE_CONTEXT();
+            SYSTRACE_ASYNC_END("OpenGLTimerQueryFence", intptr_t(state.get()));
        }
        platform.destroyFence(fence);
    });
--- a/Show More
+++ b/Show More