backend-test: centralize read pixel logic

Metal, fix callbacks being called only once (#7856 )
minor libutils improvements
2024-05-16 15:08:56 -07:00 · 2024-05-15 10:50:10 -07:00 · 2024-05-14 13:22:38 -07:00 · 2024-05-14 13:21:38 -07:00 · 2024-05-14 13:21:24 -07:00 · 2024-05-14 19:08:50 +00:00
35 changed files with 492 additions and 682 deletions
--- a/BUILDING.md
+++ b/BUILDING.md
@@ -73,7 +73,6 @@ The following CMake options are boolean options specific to Filament:
 - `FILAMENT_SUPPORTS_VULKAN`:      Include the Vulkan backend
 - `FILAMENT_INSTALL_BACKEND_TEST`: Install the backend test library so it can be consumed on iOS
 - `FILAMENT_USE_EXTERNAL_GLES3`:   Experimental: Compile Filament against OpenGL ES 3
- `FILAMENT_USE_SWIFTSHADER`:      Compile Filament against SwiftShader
 - `FILAMENT_SKIP_SAMPLES`:         Don't build sample apps

 To turn an option on or off:
@@ -426,7 +425,7 @@ value is the desired roughness between 0 and 1.

 ## Generating C++ documentation

-To generate the documentation you must first install `doxygen` and `graphviz`, then run the 
+To generate the documentation you must first install `doxygen` and `graphviz`, then run the
 following commands:

 ```shell
@@ -436,32 +435,27 @@ doxygen docs/doxygen/filament.doxygen

 Finally simply open `docs/html/index.html` in your web browser.

-## SwiftShader
+## Software Rasterization

-To try out Filament's Vulkan support with SwiftShader, first build SwiftShader and set the
-`SWIFTSHADER_LD_LIBRARY_PATH` variable to the folder that contains `libvk_swiftshader.dylib`:
+We have tested swiftshader for running software rasterization on the Vulkan backend. To use this,
+please first make sure that the [Vulkan SDK](https://www.lunarg.com/vulkan-sdk/) is installed on
+your machine. If you are doing a manual installation of the SDK on Linux, you will have to source
+`setup-env.sh` in the SDK's root folder to make sure the Vulkan loader is the first lib loaded.
+
+### Swiftshader (Vulkan) [tested on macOS and Linux]
+
+First, build SwiftShader

 ```shell
 git clone https://github.com/google/swiftshader.git
 cd swiftshader/build
 cmake .. &&  make -j
-export SWIFTSHADER_LD_LIBRARY_PATH=`pwd`
 ```

-Next, go to your Filament repo and use the [easy build](#easy-build) script with `-t`.
-
-## SwiftShader for CI
-
-Continuous testing turnaround can be quite slow if you need to build SwiftShader from scratch, so we
-provide an Ubuntu-based Docker image that has it already built. The Docker image also includes
-everything necessary for building Filament. You can fetch and run the image as follows:
-
+and then set `VK_ICD_FILENAMES` to the ICD json produced in the build. For example,
 ```shell
-docker pull ghcr.io/filament-assets/swiftshader
-docker run -it ghcr.io/filament-assets/swiftshader
+export VK_ICD_FILENAMES=/Users/user/swiftshader/build/Darwin/vk_swiftshader_icd.json
 ```

-To do more with the container, see the helper script at `build/swiftshader/test.sh`.
+Build Filament as normal and use the vulkan backend.

-If you are a team member, you can update the public image to the latest SwiftShader by
-following the instructions at the top of `build/swiftshader/Dockerfile`.
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -21,8 +21,6 @@ project(TNT)
 # ==================================================================================================
 option(FILAMENT_USE_EXTERNAL_GLES3 "Experimental: Compile Filament against OpenGL ES 3" OFF)

-option(FILAMENT_USE_SWIFTSHADER "Compile Filament against SwiftShader" OFF)
-
 option(FILAMENT_ENABLE_LTO "Enable link-time optimizations if supported by the compiler" OFF)

 option(FILAMENT_SKIP_SAMPLES "Don't build samples" OFF)
@@ -145,11 +143,6 @@ if (LINUX)
            add_definitions(-DFILAMENT_SUPPORTS_XCB)
        endif()

-        # Default Swiftshader build does not enable the xlib extension
-        if (FILAMENT_SUPPORTS_XLIB AND FILAMENT_USE_SWIFTSHADER)
-            set(FILAMENT_SUPPORTS_XLIB OFF)
-        endif()
-
        if (FILAMENT_SUPPORTS_XLIB)
            add_definitions(-DFILAMENT_SUPPORTS_XLIB)
        endif()
@@ -327,10 +320,6 @@ if (FILAMENT_SUPPORTS_EGL_ON_LINUX)
  set(EGL TRUE)
 endif()

-if (FILAMENT_USE_SWIFTSHADER)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DFILAMENT_USE_SWIFTSHADER")
-endif()
-
 if (WIN32)
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D_USE_MATH_DEFINES=1")
 endif()
@@ -451,8 +440,13 @@ endif()
 if (NOT WEBGL)
    set(GC_SECTIONS "-Wl,--gc-sections")
 endif()
+
 set(B_SYMBOLIC_FUNCTIONS "-Wl,-Bsymbolic-functions")

+if (ANDROID)
+set(BINARY_ALIGNMENT "-Wl,-z,max-page-size=16384")
+endif()
+
 if (APPLE)
    set(GC_SECTIONS "-Wl,-dead_strip")
    set(B_SYMBOLIC_FUNCTIONS "")
@@ -466,7 +460,7 @@ if (APPLE)
 endif()

 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${GC_SECTIONS}")
-set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} ${GC_SECTIONS} ${B_SYMBOLIC_FUNCTIONS}")
+set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} ${GC_SECTIONS} ${B_SYMBOLIC_FUNCTIONS} ${BINARY_ALIGNMENT}")

 if (WEBGL_PTHREADS)
    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -pthread")
@@ -678,21 +672,6 @@ else()
    set(IMPORT_EXECUTABLES ${FILAMENT}/${IMPORT_EXECUTABLES_DIR}/ImportExecutables-${CMAKE_BUILD_TYPE}.cmake)
 endif()

-# ==================================================================================================
-# Try to find Vulkan if the SDK is installed, otherwise fall back to the bundled version.
-# This needs to stay in our top-level CMakeLists because it sets up variables that are used by the
-# "bluevk" and "samples" targets.
-# ==================================================================================================
-
-if (FILAMENT_USE_SWIFTSHADER)
-    if (NOT FILAMENT_SUPPORTS_VULKAN)
-        message(ERROR "SwiftShader is only useful when Vulkan is enabled.")
-    endif()
-    find_library(SWIFTSHADER_VK NAMES vk_swiftshader HINTS "$ENV{SWIFTSHADER_LD_LIBRARY_PATH}")
-    message(STATUS "Found SwiftShader VK library in: ${SWIFTSHADER_VK}.")
-    add_definitions(-DFILAMENT_VKLIBRARY_PATH=\"${SWIFTSHADER_VK}\")
-endif()
-
 # ==================================================================================================
 # Common Functions
 # ==================================================================================================
--- a/android/filamat-android/CMakeLists.txt
+++ b/android/filamat-android/CMakeLists.txt
@@ -38,6 +38,7 @@ set(FILAMAT_INCLUDE_DIRS
 include_directories(${FILAMENT_DIR}/include)

 set(CMAKE_SHARED_LINKER_FLAGS_RELEASE "${CMAKE_SHARED_LINKER_FLAGS_RELEASE} -Wl,--version-script=${CMAKE_SOURCE_DIR}/libfilamat-jni.map")
+set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,max-page-size=16384")

 add_library(filamat-jni SHARED src/main/cpp/MaterialBuilder.cpp)
 target_include_directories(filamat-jni PRIVATE ${FILAMAT_INCLUDE_DIRS})
--- a/android/filament-android/CMakeLists.txt
+++ b/android/filament-android/CMakeLists.txt
@@ -59,6 +59,7 @@ endif()

 set(VERSION_SCRIPT "${CMAKE_CURRENT_SOURCE_DIR}/libfilament-jni.map")
 set(CMAKE_SHARED_LINKER_FLAGS_RELEASE "${CMAKE_SHARED_LINKER_FLAGS_RELEASE} -Wl,--version-script=${VERSION_SCRIPT}")
+set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,max-page-size=16384")

 add_library(filament-jni SHARED
    src/main/cpp/BufferObject.cpp
--- a/android/filament-utils-android/CMakeLists.txt
+++ b/android/filament-utils-android/CMakeLists.txt
@@ -31,6 +31,7 @@ set_target_properties(iblprefilter PROPERTIES IMPORTED_LOCATION
        ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libfilament-iblprefilter.a)

 set(CMAKE_SHARED_LINKER_FLAGS_RELEASE "${CMAKE_SHARED_LINKER_FLAGS_RELEASE} -Wl,--version-script=${CMAKE_CURRENT_SOURCE_DIR}/libfilament-utils-jni.map")
+set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,max-page-size=16384")

 add_library(filament-utils-jni SHARED
        src/main/cpp/AutomationEngine.cpp
--- a/android/gltfio-android/CMakeLists.txt
+++ b/android/gltfio-android/CMakeLists.txt
@@ -44,6 +44,7 @@ set_target_properties(uberarchive PROPERTIES IMPORTED_LOCATION
        ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libuberarchive.a)

 set(CMAKE_SHARED_LINKER_FLAGS_RELEASE "${CMAKE_SHARED_LINKER_FLAGS_RELEASE} -Wl,--version-script=${CMAKE_CURRENT_SOURCE_DIR}/libgltfio-jni.map")
+set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,max-page-size=16384")

 set(GLTFIO_SRCS
        ${GLTFIO_DIR}/include/gltfio/Animator.h
--- a/build.sh
+++ b/build.sh
@@ -44,8 +44,6 @@ function print_help {
    echo "        Exclude Vulkan support from the Android build."
    echo "    -s"
    echo "        Add iOS simulator support to the iOS build."
-    echo "    -t"
-    echo "        Enable SwiftShader support for Vulkan in desktop builds."
    echo "    -e"
    echo "        Enable EGL on Linux support for desktop builds."
    echo "    -l"
@@ -165,8 +163,6 @@ INSTALL_COMMAND=
 VULKAN_ANDROID_OPTION="-DFILAMENT_SUPPORTS_VULKAN=ON"
 VULKAN_ANDROID_GRADLE_OPTION=""

-SWIFTSHADER_OPTION="-DFILAMENT_USE_SWIFTSHADER=OFF"
-
 EGL_ON_LINUX_OPTION="-DFILAMENT_SUPPORTS_EGL_ON_LINUX=OFF"

 MATDBG_OPTION="-DFILAMENT_ENABLE_MATDBG=OFF"
@@ -233,7 +229,6 @@ function build_desktop_target {
            -DIMPORT_EXECUTABLES_DIR=out \
            -DCMAKE_BUILD_TYPE="$1" \
            -DCMAKE_INSTALL_PREFIX="../${lc_target}/filament" \
-            ${SWIFTSHADER_OPTION} \
            ${EGL_ON_LINUX_OPTION} \
            ${MATDBG_OPTION} \
            ${MATOPT_OPTION} \
@@ -794,7 +789,7 @@ function check_debug_release_build {

 pushd "$(dirname "$0")" > /dev/null

-while getopts ":hacCfgijmp:q:uvslwtedk:bx:" opt; do
+while getopts ":hacCfgijmp:q:uvslwedk:bx:" opt; do
    case ${opt} in
        h)
            print_help
@@ -913,10 +908,6 @@ while getopts ":hacCfgijmp:q:uvslwtedk:bx:" opt; do
            IOS_BUILD_SIMULATOR=true
            echo "iOS simulator support enabled."
            ;;
-        t)
-            SWIFTSHADER_OPTION="-DFILAMENT_USE_SWIFTSHADER=ON"
-            echo "SwiftShader support enabled."
-            ;;
        e)
            EGL_ON_LINUX_OPTION="-DFILAMENT_SUPPORTS_EGL_ON_LINUX=ON -DFILAMENT_SKIP_SDL2=ON -DFILAMENT_SKIP_SAMPLES=ON"
            echo "EGL on Linux support enabled; skipping SDL2."
--- a/build/swiftshader/Dockerfile
+++ b/build/swiftshader/Dockerfile
@@ -1,53 +0,0 @@
-# Build the image:
-#   docker build --no-cache --tag ssfilament -f build/swiftshader/Dockerfile .
-#   docker tag ssfilament ghcr.io/filament-assets/swiftshader
-#
-# Publish the image:
-#   docker login ghcr.io --username <user> --password <token>
-#   docker push ghcr.io/filament-assets/swiftshader
-#
-# Run the image and mount the current directory:
-#   docker run -it -v `pwd`:/trees/filament -t ssfilament
-
-FROM ubuntu:focal
-WORKDIR /trees
-ARG DEBIAN_FRONTEND=noninteractive
-ENV SWIFTSHADER_LD_LIBRARY_PATH=/trees/swiftshader/build
-ENV CXXFLAGS='-fno-builtin -Wno-pass-failed'
-
-RUN apt-get update && \
-    apt-get --no-install-recommends install -y \
-	apt-transport-https \
-	apt-utils \
-	build-essential \
-	cmake \
-	ca-certificates \
-	git \
-	ninja-build \
-	python \
-	python3 \
-	xorg-dev \
-	clang-7 \
-	libc++-7-dev \
-	libc++abi-7-dev \
-	lldb
-
-# Ensure that clang is used instead of gcc.
-RUN set -eux ;\
-    update-alternatives --install /usr/bin/clang clang /usr/bin/clang-7 100 ;\
-    update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-7 100 ;\
-    update-alternatives --install /usr/bin/cc cc /usr/bin/clang 100 ;\
-    update-alternatives --install /usr/bin/c++ c++ /usr/bin/clang++ 100
-
-# Get patch files from the local Filament tree.
-COPY build/swiftshader/*.diff .
-
-# Clone SwiftShader, apply patches, and build it.
-RUN set -eux ;\
-	git clone https://swiftshader.googlesource.com/SwiftShader swiftshader ;\
-    cd swiftshader ;\
-	git checkout 139f5c3 ;\
-	git apply /trees/*.diff ;\
-    cd build ;\
-    cmake .. -GNinja -DCMAKE_BUILD_TYPE=Release ;\
-    ninja
--- a/build/swiftshader/gallery.py
+++ b/build/swiftshader/gallery.py
@@ -1,56 +0,0 @@
-#!/usr/bin/env python3
-
-from pathlib import Path
-import os
-
-spath = os.path.dirname(os.path.realpath(__file__))
-
-path = Path(spath)
-
-folder = "../../results/"
-
-images = list(path.glob(folder + '*.png'))
-
-images.sort()
-
-gallery = open(path.absolute().joinpath(folder + 'index.html'), 'w')
-
-gallery.write("""<html>
-<head>
-<script type="module" src="https://unpkg.com/img-comparison-slider@latest/dist/component/component.esm.js"></script>
-<script nomodule="" src="https://unpkg.com/img-comparison-slider@latest/dist/component/component.js"></script>
-<link rel="stylesheet" href="https://unpkg.com/img-comparison-slider@latest/dist/collection/styles/initial.css"/>
-<style>
-    h2 {
-        font-weight: normal;
-        margin-top: 150px;
-        margin-bottom: 20px;
-    }
-    a {
-        text-decoration: none;
-        font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
-        color: blue;
-    }
-    a:hover {
-        font-weight: bold;
-    }
-</style>
-</head>
-<body>
-""")
-
-tag = ''
-
-for image in images:
-    group = image.stem.rstrip('0123456789')
-    before = f'https://filament-assets.github.io/golden/{group}/{image.name}'
-    after = image.name
-    gallery.write('\n')
-    gallery.write(f'<h2><a href="{image.stem}.json">{image.stem}.json</a></h2>\n')
-    gallery.write('<img-comparison-slider>\n')
-    gallery.write(f'<img slot="before" src="{before}" /> <img slot="after" src="{after}" />\n')
-    gallery.write('</img-comparison-slider>\n')
-
-gallery.write("""</body>
-</html>
-""")
--- a/build/swiftshader/patch_00.diff
+++ b/build/swiftshader/patch_00.diff
@@ -1,62 +0,0 @@
-diff --git a/src/Vulkan/VkPipeline.cpp b/src/Vulkan/VkPipeline.cpp
-index 86913ec72..3b35345af 100644
--- a/src/Vulkan/VkPipeline.cpp
-+++ b/src/Vulkan/VkPipeline.cpp
-@@ -71,7 +71,56 @@ std::vector<uint32_t> preprocessSpirv(
- 	if(optimize)
- 	{
- 		// Full optimization list taken from spirv-opt.
-		opt.RegisterPerformancePasses();
-+
-+		// We have removed CreateRedundancyEliminationPass because it segfaults when encountering:
-+		//     %389 = OpCompositeConstruct %7 %386 %387 %388 %86
-+		// When inserting an entry into instruction_to_value_ (which is an unordered_map)
-+		// This could perhaps be investigated further with help from asan.
-+
-+		using namespace spvtools;
-+		opt.RegisterPass(CreateWrapOpKillPass())
-+			.RegisterPass(CreateDeadBranchElimPass())
-+			.RegisterPass(CreateMergeReturnPass())
-+			.RegisterPass(CreateInlineExhaustivePass())
-+			.RegisterPass(CreateAggressiveDCEPass())
-+			.RegisterPass(CreatePrivateToLocalPass())
-+			.RegisterPass(CreateLocalSingleBlockLoadStoreElimPass())
-+			.RegisterPass(CreateLocalSingleStoreElimPass())
-+			.RegisterPass(CreateAggressiveDCEPass())
-+			.RegisterPass(CreateScalarReplacementPass())
-+			.RegisterPass(CreateLocalAccessChainConvertPass())
-+			.RegisterPass(CreateLocalSingleBlockLoadStoreElimPass())
-+			.RegisterPass(CreateLocalSingleStoreElimPass())
-+			.RegisterPass(CreateAggressiveDCEPass())
-+			.RegisterPass(CreateLocalMultiStoreElimPass())
-+			.RegisterPass(CreateAggressiveDCEPass())
-+			.RegisterPass(CreateCCPPass())
-+			.RegisterPass(CreateAggressiveDCEPass())
-+			.RegisterPass(CreateLoopUnrollPass(true))
-+			.RegisterPass(CreateDeadBranchElimPass())
-+			.RegisterPass(CreateRedundancyEliminationPass()) // workaround for SEGFAULT
-+			.RegisterPass(CreateCombineAccessChainsPass())
-+			.RegisterPass(CreateSimplificationPass())
-+			.RegisterPass(CreateScalarReplacementPass())
-+			.RegisterPass(CreateLocalAccessChainConvertPass())
-+			.RegisterPass(CreateLocalSingleBlockLoadStoreElimPass())
-+			.RegisterPass(CreateLocalSingleStoreElimPass())
-+			.RegisterPass(CreateAggressiveDCEPass())
-+			.RegisterPass(CreateSSARewritePass())
-+			.RegisterPass(CreateAggressiveDCEPass())
-+			.RegisterPass(CreateVectorDCEPass())
-+			.RegisterPass(CreateDeadInsertElimPass())
-+			.RegisterPass(CreateDeadBranchElimPass())
-+			.RegisterPass(CreateSimplificationPass())
-+			.RegisterPass(CreateIfConversionPass())
-+			.RegisterPass(CreateCopyPropagateArraysPass())
-+			.RegisterPass(CreateReduceLoadSizePass())
-+			.RegisterPass(CreateAggressiveDCEPass())
-+			.RegisterPass(CreateBlockMergePass())
-+			.RegisterPass(CreateRedundancyEliminationPass()) // workaround for SEGFAULT
-+			.RegisterPass(CreateDeadBranchElimPass())
-+			.RegisterPass(CreateBlockMergePass())
-+			.RegisterPass(CreateSimplificationPass());
- 	}
- 
- 	std::vector<uint32_t> optimized;
--- a/build/swiftshader/test.sh
+++ b/build/swiftshader/test.sh
@@ -1,127 +0,0 @@
-#!/bin/bash
-set -e
-
-function print_help {
-    local self_name=$(basename "$0")
-    echo "This script issues docker commands for testing Filament with SwiftShader."
-    echo "The usual sequence of commands is: fetch, start, build filament release, and run."
-    echo ""
-    echo "Usage:"
-    echo "    $self_name [command]"
-    echo ""
-    echo "Commands:"
-    echo "    build filament [debug | release]"
-    echo "        Use the container to build Filament."
-    echo "    build swiftshader [debug | release]"
-    echo "        Use the container to do a clean rebuild of SwiftShader."
-    echo "        (Note that the container already has SwiftShader built.)"
-    echo "    fetch"
-    echo "        Download the docker image from the central repository."
-    echo "    help"
-    echo "        Print this help message."
-    echo "    logs"
-    echo "        Print messages from the container's kernel ring buffer."
-    echo "        This is useful for diagnosing OOM issues."
-    echo "    run [lldb]"
-    echo "        Launch a test inside the container, optionally via lldb."
-    echo "    shell"
-    echo "        Interact with a bash prompt in the container."
-    echo "    start"
-    echo "        Start a container from the image."
-    echo "    stop"
-    echo "        Stop the container."
-    echo ""
-}
-
-# Change the current working directory to the Filament root.
-pushd "$(dirname "$0")/../.." > /dev/null
-
-if [[ "$1" == "build" ]] && [[ "$2" == "filament" ]]; then
-    docker exec runner filament/build.sh -t $3 gltf_viewer
-    exit $?
-fi
-
-if [[ "$1" == "build" ]] && [[ "$2" == "swiftshader" ]]; then
-    BUILD_TYPE="$3"
-    BUILD_TYPE="$(tr '[:lower:]' '[:upper:]' <<< ${BUILD_TYPE:0:1})${BUILD_TYPE:1}"
-    docker exec --workdir /trees/swiftshader runner rm -rf build
-    docker exec --workdir /trees/swiftshader runner mkdir build
-    docker exec --workdir /trees/swiftshader/build runner cmake -GNinja -DCMAKE_BUILD_TYPE="$BUILD_TYPE" ..
-    docker exec --workdir /trees/swiftshader/build runner ninja
-    exit $?
-fi
-
-if [[ "$1" == "fetch" ]]; then
-    docker pull ghcr.io/filament-assets/swiftshader:latest
-    docker tag ghcr.io/filament-assets/swiftshader:latest ssfilament
-    exit $?
-fi
-
-if [[ "$1" == "help" ]]; then
-    print_help
-    exit 0
-fi
-
-if [[ "$1" == "logs" ]]; then
-    docker exec runner dmesg --human --read-clear
-    exit $?
-fi
-
-if [[ "$1" == "run" ]] && [[ "$2" == "lldb" ]]; then
-    docker exec -i --workdir /trees/filament/results runner \
-          lldb --batch -o run -o bt -- \
-          ../out/cmake-release/samples/gltf_viewer \
-          --headless \
-          --batch ../libs/viewer/tests/basic.json \
-          --api vulkan
-    docker exec runner /trees/filament/build/swiftshader/gallery.py
-    exit $?
-fi
-
-if [[ "$1" == "run" ]]; then
-    docker exec --tty  --workdir /trees/filament/results runner \
-          /usr/bin/catchsegv \
-          ../out/cmake-release/samples/gltf_viewer \
-          --headless \
-          --batch ../libs/viewer/tests/basic.json \
-          --api vulkan
-    docker exec runner /trees/filament/build/swiftshader/gallery.py
-    exit $?
-fi
-
-if [[ "$1" == "shell" ]]; then
-    docker exec --interactive --tty runner /bin/bash
-    exit $?
-fi
-
-# Notes on options being passed to docker's run command:
-#
-# - The memory constraint seems to prevent an OOM signal in GitHub Actions.
-# - The cap / security args allow use of lldb and creation of core dumps.
-# - The privileged arg allows use of dmesg for examining OOM logs.
-#
-# Currently, a GitHub Actions VM has 2 CPUs, 7 GB RAM, and 14 GB of SSD disk space.
-#
-# Please be aware that Docker Desktop might impose additional resource constraints, and that those
-# settings can only be controlled with its GUI. We recommend at least 7 GB of memory and 2 GB swap.
-if [[ "$1" == "start" ]]; then
-    mkdir -p results
-    docker run --tty --rm --detach --privileged \
-          --memory 6.5g \
-          --name runner \
-          --cap-add=SYS_PTRACE \
-          --security-opt seccomp=unconfined \
-          --security-opt apparmor=unconfined \
-          --volume `pwd`:/trees/filament \
-          --workdir /trees \
-          ssfilament
-    exit $?
-fi
-
-if [[ "$1" == "stop" ]]; then
-    docker container rm runner --force
-    exit $?
-fi
-
-print_help
-exit 1
--- a/filament/backend/CMakeLists.txt
+++ b/filament/backend/CMakeLists.txt
@@ -66,7 +66,7 @@ set(PRIVATE_HDRS
 # OpenGL / OpenGL ES Sources
 # ==================================================================================================

-if (FILAMENT_SUPPORTS_OPENGL AND NOT FILAMENT_USE_EXTERNAL_GLES3 AND NOT FILAMENT_USE_SWIFTSHADER)
+if (FILAMENT_SUPPORTS_OPENGL AND NOT FILAMENT_USE_EXTERNAL_GLES3)
    list(APPEND SRCS
            include/backend/platforms/OpenGLPlatform.h
            src/opengl/gl_headers.cpp
@@ -417,6 +417,7 @@ if (APPLE OR LINUX)
        test/test_MissingRequiredAttributes.cpp
        test/test_ReadPixels.cpp
        test/test_BufferUpdates.cpp
+        test/test_Callbacks.cpp
        test/test_MRT.cpp
        test/test_LoadImage.cpp
        test/test_StencilBuffer.cpp
--- a/filament/backend/include/backend/platforms/VulkanPlatform.h
+++ b/filament/backend/include/backend/platforms/VulkanPlatform.h
@@ -23,9 +23,9 @@

 #include <utils/CString.h>
 #include <utils/FixedCapacityVector.h>
+#include <utils/Hash.h>
 #include <utils/PrivateImplementation.h>

-#include <string_view>
 #include <tuple>
 #include <unordered_set>

@@ -47,6 +47,14 @@ struct VulkanPlatformPrivate;
 class VulkanPlatform : public Platform, utils::PrivateImplementation<VulkanPlatformPrivate> {
 public:

+    struct ExtensionHashFn {
+        std::size_t operator()(utils::CString const& s) const noexcept {
+            return std::hash<std::string>{}(s.data());
+        }
+    };
+    // Utility for managing device or instance extensions during initialization.
+    using ExtensionSet = std::unordered_set<utils::CString, ExtensionHashFn>;
+
    /**
     * A collection of handles to objects and metadata that comprises a Vulkan context. The client
     * can instantiate this struct and pass to Engine::Builder::sharedContext if they wishes to
@@ -192,6 +200,13 @@ public:
    virtual SwapChainPtr createSwapChain(void* nativeWindow, uint64_t flags = 0,
            VkExtent2D extent = {0, 0});

+    /**
+     * Allows implementers to provide instance extensions that they'd like to include in the
+     * instance creation.
+     * @return          A set of extensions to enable for the instance.
+     */
+    virtual ExtensionSet getRequiredInstanceExtensions() { return {}; }
+
    /**
     * Destroy the swapchain.
     * @param handle    The handle returned by createSwapChain()
@@ -236,10 +251,9 @@ public:
    VkQueue getGraphicsQueue() const noexcept;

 private:
-    // Platform dependent helper methods
-    using ExtensionSet = std::unordered_set<std::string_view>;
-    static ExtensionSet getRequiredInstanceExtensions();
+    static ExtensionSet getSwapchainInstanceExtensions();

+    // Platform dependent helper methods
    using SurfaceBundle = std::tuple<VkSurfaceKHR, VkExtent2D>;
    static SurfaceBundle createVkSurfaceKHR(void* nativeWindow, VkInstance instance,
            uint64_t flags) noexcept;
--- a/filament/backend/include/private/backend/DriverAPI.inc
+++ b/filament/backend/include/private/backend/DriverAPI.inc
@@ -144,8 +144,7 @@ DECL_DRIVER_API_N(setFrameScheduledCallback,
 DECL_DRIVER_API_N(setFrameCompletedCallback,
        backend::SwapChainHandle, sch,
        backend::CallbackHandler*, handler,
-        backend::CallbackHandler::Callback, callback,
-        void*, user)
+        utils::Invocable<void(void)>&&, callback)

 DECL_DRIVER_API_N(setPresentationTime,
        int64_t, monotonic_clock_ns)
@@ -502,7 +501,7 @@ DECL_DRIVER_API_N(blit,
        math::uint2, size)

 DECL_DRIVER_API_N(bindPipeline,
-        backend::PipelineState, state)
+        backend::PipelineState const&, state)

 DECL_DRIVER_API_N(bindRenderPrimitive,
        backend::RenderPrimitiveHandle, rph)
--- a/filament/backend/src/PlatformFactory.cpp
+++ b/filament/backend/src/PlatformFactory.cpp
@@ -29,21 +29,21 @@
        #include "backend/platforms/PlatformCocoaTouchGL.h"
    #endif
 #elif defined(__APPLE__)
-    #if defined(FILAMENT_SUPPORTS_OPENGL) && !defined(FILAMENT_USE_EXTERNAL_GLES3) && !defined(FILAMENT_USE_SWIFTSHADER)
+    #if defined(FILAMENT_SUPPORTS_OPENGL) && !defined(FILAMENT_USE_EXTERNAL_GLES3)
        #include <backend/platforms/PlatformCocoaGL.h>
    #endif
 #elif defined(__linux__)
    #if defined(FILAMENT_SUPPORTS_X11)
-        #if defined(FILAMENT_SUPPORTS_OPENGL) && !defined(FILAMENT_USE_EXTERNAL_GLES3) && !defined(FILAMENT_USE_SWIFTSHADER)
+        #if defined(FILAMENT_SUPPORTS_OPENGL) && !defined(FILAMENT_USE_EXTERNAL_GLES3)
            #include "backend/platforms/PlatformGLX.h"
        #endif
    #elif defined(FILAMENT_SUPPORTS_EGL_ON_LINUX)
-        #if defined(FILAMENT_SUPPORTS_OPENGL) && !defined(FILAMENT_USE_EXTERNAL_GLES3) && !defined(FILAMENT_USE_SWIFTSHADER)
+        #if defined(FILAMENT_SUPPORTS_OPENGL) && !defined(FILAMENT_USE_EXTERNAL_GLES3)
            #include "backend/platforms/PlatformEGLHeadless.h"
        #endif
    #endif
 #elif defined(WIN32)
-    #if defined(FILAMENT_SUPPORTS_OPENGL) && !defined(FILAMENT_USE_EXTERNAL_GLES3) && !defined(FILAMENT_USE_SWIFTSHADER)
+    #if defined(FILAMENT_SUPPORTS_OPENGL) && !defined(FILAMENT_USE_EXTERNAL_GLES3)
        #include "backend/platforms/PlatformWGL.h"
    #endif
 #elif defined(__EMSCRIPTEN__)
@@ -111,8 +111,7 @@ Platform* PlatformFactory::create(Backend* backend) noexcept {
    }
    assert_invariant(*backend == Backend::OPENGL);
    #if defined(FILAMENT_SUPPORTS_OPENGL)
-        #if defined(FILAMENT_USE_EXTERNAL_GLES3) || defined(FILAMENT_USE_SWIFTSHADER)
-            // Swiftshader OpenGLES support is deprecated and incomplete
+        #if defined(FILAMENT_USE_EXTERNAL_GLES3)
            return nullptr;
        #elif defined(__ANDROID__)
            return new PlatformEGLAndroid();
--- a/filament/backend/src/metal/MetalDriver.mm
+++ b/filament/backend/src/metal/MetalDriver.mm
@@ -243,10 +243,10 @@ void MetalDriver::setFrameScheduledCallback(
    swapChain->setFrameScheduledCallback(handler, std::move(callback));
 }

-void MetalDriver::setFrameCompletedCallback(Handle<HwSwapChain> sch,
-        CallbackHandler* handler, CallbackHandler::Callback callback, void* user) {
+void MetalDriver::setFrameCompletedCallback(
+        Handle<HwSwapChain> sch, CallbackHandler* handler, utils::Invocable<void(void)>&& callback) {
    auto* swapChain = handle_cast<MetalSwapChain>(sch);
-    swapChain->setFrameCompletedCallback(handler, callback, user);
+    swapChain->setFrameCompletedCallback(handler, std::move(callback));
 }

 void MetalDriver::execute(std::function<void(void)> const& fn) noexcept {
@@ -1637,7 +1637,7 @@ void MetalDriver::finalizeSamplerGroup(MetalSamplerGroup* samplerGroup) {
    }
 }

-void MetalDriver::bindPipeline(PipelineState ps) {
+void MetalDriver::bindPipeline(PipelineState const& ps) {
    ASSERT_PRECONDITION(mContext->currentRenderPassEncoder != nullptr,
            "bindPipeline() without a valid command encoder.");

--- a/filament/backend/src/metal/MetalHandles.h
+++ b/filament/backend/src/metal/MetalHandles.h
@@ -75,7 +75,7 @@ public:

    void setFrameScheduledCallback(CallbackHandler* handler, FrameScheduledCallback&& callback);
    void setFrameCompletedCallback(
-            CallbackHandler* handler, CallbackHandler::Callback callback, void* user);
+            CallbackHandler* handler, utils::Invocable<void(void)>&& callback);

    // For CAMetalLayer-backed SwapChains, presents the drawable or schedules a
    // FrameScheduledCallback.
@@ -119,13 +119,12 @@ private:
    // PresentCallable object.
    struct {
        CallbackHandler* handler = nullptr;
-        FrameScheduledCallback callback = {};
+        std::shared_ptr<FrameScheduledCallback> callback = nullptr;
    } frameScheduled;

    struct {
        CallbackHandler* handler = nullptr;
-        CallbackHandler::Callback callback = {};
-        void* user = nullptr;
+        std::shared_ptr<utils::Invocable<void(void)>> callback = nullptr;
    } frameCompleted;
 };

--- a/filament/backend/src/metal/MetalHandles.mm
+++ b/filament/backend/src/metal/MetalHandles.mm
@@ -224,14 +224,13 @@ void MetalSwapChain::ensureDepthStencilTexture() {
 void MetalSwapChain::setFrameScheduledCallback(
        CallbackHandler* handler, FrameScheduledCallback&& callback) {
    frameScheduled.handler = handler;
-    frameScheduled.callback = std::move(callback);
+    frameScheduled.callback = std::make_shared<FrameScheduledCallback>(std::move(callback));
 }

-void MetalSwapChain::setFrameCompletedCallback(CallbackHandler* handler,
-        CallbackHandler::Callback callback, void* user) {
+void MetalSwapChain::setFrameCompletedCallback(
+        CallbackHandler* handler, utils::Invocable<void(void)>&& callback) {
    frameCompleted.handler = handler;
-    frameCompleted.callback = callback;
-    frameCompleted.user = user;
+    frameCompleted.callback = std::make_shared<utils::Invocable<void(void)>>(std::move(callback));
 }

 void MetalSwapChain::present() {
@@ -304,17 +303,17 @@ void MetalSwapChain::scheduleFrameScheduledCallback() {
    assert_invariant(drawable);

    struct Callback {
-        Callback(FrameScheduledCallback&& callback, id<CAMetalDrawable> drawable,
+        Callback(std::shared_ptr<FrameScheduledCallback> callback, id<CAMetalDrawable> drawable,
                MetalDriver* driver)
-            : f(std::move(callback)), data(PresentDrawableData::create(drawable, driver)) {}
-        FrameScheduledCallback f;
+            : f(callback), data(PresentDrawableData::create(drawable, driver)) {}
+        std::shared_ptr<FrameScheduledCallback> f;
        // PresentDrawableData* is destroyed by maybePresentAndDestroyAsync() later.
        std::unique_ptr<PresentDrawableData> data;
        static void func(void* user) {
            auto* const c = reinterpret_cast<Callback*>(user);
            PresentDrawableData* presentDrawableData = c->data.release();
            PresentCallable presentCallable(presentDrawable, presentDrawableData);
-            c->f(presentCallable);
+            c->f->operator()(presentCallable);
            delete c;
        }
    };
@@ -322,7 +321,7 @@ void MetalSwapChain::scheduleFrameScheduledCallback() {
    // This callback pointer will be captured by the block. Even if the scheduled handler is never
    // called, the unique_ptr will still ensure we don't leak memory.
    __block auto callback =
-            std::make_unique<Callback>(std::move(frameScheduled.callback), drawable, context.driver);
+            std::make_unique<Callback>(frameScheduled.callback, drawable, context.driver);

    backend::CallbackHandler* handler = frameScheduled.handler;
    MetalDriver* driver = context.driver;
@@ -337,13 +336,25 @@ void MetalSwapChain::scheduleFrameCompletedCallback() {
        return;
    }

-    CallbackHandler* handler = frameCompleted.handler;
-    void* user = frameCompleted.user;
-    CallbackHandler::Callback callback = frameCompleted.callback;
+    struct Callback {
+        Callback(std::shared_ptr<utils::Invocable<void(void)>> callback) : f(callback) {}
+        std::shared_ptr<utils::Invocable<void(void)>> f;
+        static void func(void* user) {
+            auto* const c = reinterpret_cast<Callback*>(user);
+            c->f->operator()();
+            delete c;
+        }
+    };

+    // This callback pointer will be captured by the block. Even if the completed handler is never
+    // called, the unique_ptr will still ensure we don't leak memory.
+    __block auto callback = std::make_unique<Callback>(frameCompleted.callback);
+
+    CallbackHandler* handler = frameCompleted.handler;
    MetalDriver* driver = context.driver;
    [getPendingCommandBuffer(&context) addCompletedHandler:^(id<MTLCommandBuffer> cb) {
-        driver->scheduleCallback(handler, user, callback);
+        Callback* user = callback.release();
+        driver->scheduleCallback(handler, user, &Callback::func);
    }];
 }

--- a/filament/backend/src/noop/NoopDriver.cpp
+++ b/filament/backend/src/noop/NoopDriver.cpp
@@ -59,7 +59,7 @@ void NoopDriver::setFrameScheduledCallback(Handle<HwSwapChain> sch,
 }

 void NoopDriver::setFrameCompletedCallback(Handle<HwSwapChain> sch,
-        CallbackHandler* handler, CallbackHandler::Callback callback, void* user) {
+        CallbackHandler* handler, utils::Invocable<void(void)>&& callback) {

 }

@@ -359,7 +359,7 @@ void NoopDriver::blit(
        math::uint2 size) {
 }

-void NoopDriver::bindPipeline(PipelineState pipelineState) {
+void NoopDriver::bindPipeline(PipelineState const& pipelineState) {
 }

 void NoopDriver::bindRenderPrimitive(Handle<HwRenderPrimitive> rph) {
--- a/filament/backend/src/opengl/OpenGLDriver.cpp
+++ b/filament/backend/src/opengl/OpenGLDriver.cpp
@@ -241,7 +241,15 @@ OpenGLDriver::~OpenGLDriver() noexcept { // NOLINT(modernize-use-equals-default)
 }

 Dispatcher OpenGLDriver::getDispatcher() const noexcept {
-    return ConcreteDispatcher<OpenGLDriver>::make();
+    auto dispatcher = ConcreteDispatcher<OpenGLDriver>::make();
+    if (mContext.isES2()) {
+        dispatcher.draw2_ = +[](Driver& driver, CommandBase* base, intptr_t* next){
+            using Cmd = COMMAND_TYPE(draw2);
+            OpenGLDriver& concreteDriver = static_cast<OpenGLDriver&>(driver);
+            Cmd::execute(&OpenGLDriver::draw2GLES2, concreteDriver, base, next);
+        };
+    }
+    return dispatcher;
 }

 // ------------------------------------------------------------------------------------------------
@@ -924,16 +932,18 @@ void OpenGLDriver::importTextureR(Handle<HwTexture> th, intptr_t id,
 }

 void OpenGLDriver::updateVertexArrayObject(GLRenderPrimitive* rp, GLVertexBuffer const* vb) {
-    // NOTE: this is called from draw() and must be as efficient as possible.
+    // NOTE: this is called often and must be as efficient as possible.

    auto& gl = mContext;

+#ifndef NDEBUG
    if (UTILS_LIKELY(gl.ext.OES_vertex_array_object)) {
        // The VAO for the given render primitive must already be bound.
        GLint vaoBinding;
        glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &vaoBinding);
        assert_invariant(vaoBinding == (GLint)rp->gl.vao[gl.contextIndex]);
    }
+#endif

    if (UTILS_LIKELY(rp->gl.vertexBufferVersion == vb->bufferObjectsVersion &&
                     rp->gl.stateVersion == gl.state.age)) {
@@ -949,7 +959,7 @@ void OpenGLDriver::updateVertexArrayObject(GLRenderPrimitive* rp, GLVertexBuffer
            // if a buffer is defined it must not be invalid.
            assert_invariant(vb->gl.buffers[bi]);

-            // if w're on ES2, the user shouldn't use FLAG_INTEGER_TARGET
+            // if we're on ES2, the user shouldn't use FLAG_INTEGER_TARGET
            assert_invariant(!(gl.isES2() && (attribute.flags & Attribute::FLAG_INTEGER_TARGET)));

            gl.bindBuffer(GL_ARRAY_BUFFER, vb->gl.buffers[bi]);
@@ -3459,7 +3469,7 @@ void OpenGLDriver::setFrameScheduledCallback(Handle<HwSwapChain> sch,
 }

 void OpenGLDriver::setFrameCompletedCallback(Handle<HwSwapChain> sch,
-        CallbackHandler* handler, CallbackHandler::Callback callback, void* user) {
+        CallbackHandler* handler, utils::Invocable<void(void)>&& callback) {
    DEBUG_MARKER()
 }

@@ -3837,7 +3847,7 @@ void OpenGLDriver::updateTextureLodRange(GLTexture* texture, int8_t targetLevel)
 #endif
 }

-void OpenGLDriver::bindPipeline(PipelineState state) {
+void OpenGLDriver::bindPipeline(PipelineState const& state) {
    DEBUG_MARKER()
    auto& gl = mContext;
    setRasterState(state.rasterState);
@@ -3875,20 +3885,35 @@ void OpenGLDriver::draw2(uint32_t indexOffset, uint32_t indexCount, uint32_t ins
        return;
    }

-    if (UTILS_LIKELY(instanceCount <= 1)) {
-        glDrawElements(GLenum(rp->type), (GLsizei)indexCount, rp->gl.getIndicesType(),
-                reinterpret_cast<const void*>(indexOffset * rp->gl.indicesSize));
-    } else {
-        assert_invariant(!mContext.isES2());
 #ifndef FILAMENT_SILENCE_NOT_SUPPORTED_BY_ES2
-        glDrawElementsInstanced(GLenum(rp->type), (GLsizei)indexCount,
-                rp->gl.getIndicesType(),
-                reinterpret_cast<const void*>(indexOffset * rp->gl.indicesSize),
-                (GLsizei)instanceCount);
+    assert_invariant(!mContext.isES2());
+    glDrawElementsInstanced(GLenum(rp->type), (GLsizei)indexCount,
+            rp->gl.getIndicesType(),
+            reinterpret_cast<const void*>(indexOffset * rp->gl.indicesSize),
+            (GLsizei)instanceCount);
 #endif
+
+#if FILAMENT_ENABLE_MATDBG
+    CHECK_GL_ERROR_NON_FATAL(utils::slog.e)
+#else
+    CHECK_GL_ERROR(utils::slog.e)
+#endif
+}
+
+void OpenGLDriver::draw2GLES2(uint32_t indexOffset, uint32_t indexCount, uint32_t instanceCount) {
+    GLRenderPrimitive const* const rp = mBoundRenderPrimitive;
+    if (UTILS_UNLIKELY(!rp || !mValidProgram)) {
+        return;
    }

-#ifdef FILAMENT_ENABLE_MATDBG
+    assert_invariant(mContext.isES2());
+    assert_invariant(instanceCount == 1);
+
+    glDrawElements(GLenum(rp->type), (GLsizei)indexCount, rp->gl.getIndicesType(),
+            reinterpret_cast<const void*>(indexOffset * rp->gl.indicesSize));
+
+
+#if FILAMENT_ENABLE_MATDBG
    CHECK_GL_ERROR_NON_FATAL(utils::slog.e)
 #else
    CHECK_GL_ERROR(utils::slog.e)
@@ -3907,7 +3932,11 @@ void OpenGLDriver::draw(PipelineState state, Handle<HwRenderPrimitive> rph,
    state.vertexBufferInfo = rp->vbih;
    bindPipeline(state);
    bindRenderPrimitive(rph);
-    draw2(indexOffset, indexCount, instanceCount);
+    if (UTILS_UNLIKELY(mContext.isES2())) {
+        draw2GLES2(indexOffset, indexCount, instanceCount);
+    } else {
+        draw2(indexOffset, indexCount, instanceCount);
+    }
 }

 void OpenGLDriver::dispatchCompute(Handle<HwProgram> program, math::uint3 workGroupCount) {
@@ -3934,7 +3963,7 @@ void OpenGLDriver::dispatchCompute(Handle<HwProgram> program, math::uint3 workGr
    glDispatchCompute(workGroupCount.x, workGroupCount.y, workGroupCount.z);
 #endif // BACKEND_OPENGL_LEVEL_GLES31

-#ifdef FILAMENT_ENABLE_MATDBG
+#if FILAMENT_ENABLE_MATDBG
    CHECK_GL_ERROR_NON_FATAL(utils::slog.e)
 #else
    CHECK_GL_ERROR(utils::slog.e)
--- a/filament/backend/src/opengl/OpenGLDriver.h
+++ b/filament/backend/src/opengl/OpenGLDriver.h
@@ -336,6 +336,8 @@ private:

    void setScissor(Viewport const& scissor) noexcept;

+    void draw2GLES2(uint32_t indexOffset, uint32_t indexCount, uint32_t instanceCount);
+
    // ES2 only. Uniform buffer emulation binding points
    GLuint mLastAssignedEmulatedUboId = 0;

--- a/filament/backend/src/vulkan/VulkanDriver.cpp
+++ b/filament/backend/src/vulkan/VulkanDriver.cpp
@@ -398,7 +398,7 @@ void VulkanDriver::setFrameScheduledCallback(Handle<HwSwapChain> sch,
 }

 void VulkanDriver::setFrameCompletedCallback(Handle<HwSwapChain> sch,
-        CallbackHandler* handler, CallbackHandler::Callback callback, void* user) {
+        CallbackHandler* handler, utils::Invocable<void(void)>&& callback) {
 }

 void VulkanDriver::setPresentationTime(int64_t monotonic_clock_ns) {
@@ -1763,7 +1763,7 @@ void VulkanDriver::blitDEPRECATED(TargetBufferFlags buffers,
    FVK_SYSTRACE_END();
 }

-void VulkanDriver::bindPipeline(PipelineState pipelineState) {
+void VulkanDriver::bindPipeline(PipelineState const& pipelineState) {
    FVK_SYSTRACE_CONTEXT();
    FVK_SYSTRACE_START("draw");

@@ -1873,6 +1873,12 @@ void VulkanDriver::bindPipeline(PipelineState pipelineState) {

    mPipelineCache.bindLayout(pipelineLayout);
    mPipelineCache.bindPipeline(commands);
+
+    // Since we don't statically define scissor as part of the pipeline, we need to call scissor at
+    // least once. Context: VUID-vkCmdDrawIndexed-None-07832.
+    auto const& extent = rt->getExtent();
+    scissor({0, 0, extent.width, extent.height});
+
    FVK_SYSTRACE_END();
 }

@@ -1963,7 +1969,7 @@ void VulkanDriver::scissor(Viewport scissorBox) {

    const VulkanRenderTarget* rt = mCurrentRenderPass.renderTarget;
    rt->transformClientRectToPlatform(&scissor);
-    mPipelineCache.bindScissor(cmdbuffer, scissor);
+    vkCmdSetScissor(cmdbuffer, 0, 1, &scissor);
 }

 void VulkanDriver::beginTimerQuery(Handle<HwTimerQuery> tqh) {
--- a/filament/backend/src/vulkan/VulkanPipelineCache.cpp
+++ b/filament/backend/src/vulkan/VulkanPipelineCache.cpp
@@ -79,10 +79,6 @@ void VulkanPipelineCache::bindPipeline(VulkanCommandBuffer* commands) {
    commands->setPipeline(cacheEntry->handle);
 }

-void VulkanPipelineCache::bindScissor(VkCommandBuffer cmdbuffer, VkRect2D scissor) noexcept {
-    vkCmdSetScissor(cmdbuffer, 0, 1, &scissor);
-}
-
 VulkanPipelineCache::PipelineCacheEntry* VulkanPipelineCache::createPipeline() noexcept {
    assert_invariant(mPipelineRequirements.shaders[0] && "Vertex shader is not bound.");
    assert_invariant(mPipelineRequirements.layout && "No pipeline layout specified");
@@ -306,7 +302,6 @@ void VulkanPipelineCache::gc() noexcept {
    // The Vulkan spec says: "When a command buffer begins recording, all state in that command
    // buffer is undefined." Therefore, we need to clear all bindings at this time.
    mBoundPipeline = {};
-    mCurrentScissor = {};

    // NOTE: Due to robin_map restrictions, we cannot use auto or range-based loops.

--- a/filament/backend/src/vulkan/VulkanPipelineCache.h
+++ b/filament/backend/src/vulkan/VulkanPipelineCache.h
@@ -120,9 +120,6 @@ public:
    // Creates a new pipeline if necessary and binds it using vkCmdBindPipeline.
    void bindPipeline(VulkanCommandBuffer* commands);

-    // Sets up a new scissor rectangle if it has been dirtied.
-    void bindScissor(VkCommandBuffer cmdbuffer, VkRect2D scissor) noexcept;
-
    // Each of the following methods are fast and do not make Vulkan calls.
    void bindProgram(VulkanProgram* program) noexcept;
    void bindRasterState(const RasterState& rasterState) noexcept;
@@ -263,9 +260,6 @@ private:

    // Current bindings for the pipeline and descriptor sets.
    PipelineKey mBoundPipeline = {};
-
-    // Current state for scissoring.
-    VkRect2D mCurrentScissor = {};
 };

 } // namespace filament::backend
--- a/filament/backend/src/vulkan/platform/VulkanPlatform.cpp
+++ b/filament/backend/src/vulkan/platform/VulkanPlatform.cpp
@@ -44,7 +44,11 @@ namespace {

 constexpr uint32_t const INVALID_VK_INDEX = 0xFFFFFFFF;

-typedef std::unordered_set<std::string_view> ExtensionSet;
+using ExtensionSet = VulkanPlatform::ExtensionSet;
+
+inline bool setContains(ExtensionSet const& set, utils::CString const& extension) {
+    return set.find(extension) != set.end();
+};

 #if FVK_ENABLED(FVK_DEBUG_VALIDATION)
 // These strings need to be allocated outside a function stack
@@ -80,7 +84,7 @@ FixedCapacityVector<const char*> getEnabledLayers() {

 void printDeviceInfo(VkInstance instance, VkPhysicalDevice device) {
    // Print some driver or MoltenVK information if it is available.
-    if (vkGetPhysicalDeviceProperties2KHR) {
+    if (vkGetPhysicalDeviceProperties2) {
        VkPhysicalDeviceDriverProperties driverProperties = {
                .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DRIVER_PROPERTIES,
        };
@@ -88,7 +92,7 @@ void printDeviceInfo(VkInstance instance, VkPhysicalDevice device) {
                .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROPERTIES_2,
                .pNext = &driverProperties,
        };
-        vkGetPhysicalDeviceProperties2KHR(device, &physicalDeviceProperties2);
+        vkGetPhysicalDeviceProperties2(device, &physicalDeviceProperties2);
        utils::slog.i << "Vulkan device driver: " << driverProperties.driverName << " "
                      << driverProperties.driverInfo << utils::io::endl;
    }
@@ -148,38 +152,37 @@ void printDepthFormats(VkPhysicalDevice device) {
 }
 #endif

-ExtensionSet getInstanceExtensions() {
-    std::string_view const TARGET_EXTS[] = {
-            // Request all cross-platform extensions.
-            VK_KHR_SURFACE_EXTENSION_NAME,
-            VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2_EXTENSION_NAME,
+ExtensionSet getInstanceExtensions(ExtensionSet const& externallyRequiredExts = {}) {
+    ExtensionSet const TARGET_EXTS = {
+        // Request all cross-platform extensions.
+        VK_KHR_SURFACE_EXTENSION_NAME,
+        VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2_EXTENSION_NAME,

-            // Request these if available.
+    // Request these if available.
 #if FVK_ENABLED(FVK_DEBUG_DEBUG_UTILS)
-            VK_EXT_DEBUG_UTILS_EXTENSION_NAME,
+        VK_EXT_DEBUG_UTILS_EXTENSION_NAME,
 #endif
-            VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME,
+        VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME,

 #if FVK_ENABLED(FVK_DEBUG_VALIDATION)
-            VK_EXT_DEBUG_REPORT_EXTENSION_NAME,
+        VK_EXT_DEBUG_REPORT_EXTENSION_NAME,
 #endif
    };
    ExtensionSet exts;
-    FixedCapacityVector<VkExtensionProperties> const availableExts
-            = filament::backend::enumerate(vkEnumerateInstanceExtensionProperties,
+    FixedCapacityVector<VkExtensionProperties> const availableExts =
+            filament::backend::enumerate(vkEnumerateInstanceExtensionProperties,
                    static_cast<char const*>(nullptr) /* pLayerName */);
    for (auto const& extProps: availableExts) {
-        for (auto const& targetExt: TARGET_EXTS) {
-            if (targetExt == extProps.extensionName) {
-                exts.insert(targetExt);
-            }
+        utils::CString name { extProps.extensionName };
+        if (setContains(TARGET_EXTS, name) || setContains(externallyRequiredExts, name)) {
+            exts.insert(name);
        }
    }
    return exts;
 }

 ExtensionSet getDeviceExtensions(VkPhysicalDevice device) {
-    std::string_view const TARGET_EXTS[] = {
+    ExtensionSet const TARGET_EXTS = {
 #if FVK_ENABLED(FVK_DEBUG_DEBUG_UTILS)
            VK_EXT_DEBUG_MARKER_EXTENSION_NAME,
 #endif
@@ -194,10 +197,9 @@ ExtensionSet getDeviceExtensions(VkPhysicalDevice device) {
            = filament::backend::enumerate(vkEnumerateDeviceExtensionProperties, device,
                    static_cast<const char*>(nullptr) /* pLayerName */);
    for (auto const& extension: extensions) {
-        for (auto const& targetExt: TARGET_EXTS) {
-            if (targetExt == extension.extensionName) {
-                exts.insert(targetExt);
-            }
+        utils::CString name { extension.extensionName };
+        if (setContains(TARGET_EXTS, name)) {
+            exts.insert(name);
        }
    }
    return exts;
@@ -245,7 +247,7 @@ VkInstance createInstance(ExtensionSet const& requiredExts) {
        ppEnabledExtensions[enabledExtensionCount++] = VK_EXT_VALIDATION_FEATURES_EXTENSION_NAME;
    }
    // Request platform-specific extensions.
-    for (auto const requiredExt: requiredExts) {
+    for (auto const& requiredExt: requiredExts) {
        assert_invariant(enabledExtensionCount < MAX_INSTANCE_EXTENSION_COUNT);
        ppEnabledExtensions[enabledExtensionCount++] = requiredExt.data();
    }
@@ -260,7 +262,7 @@ VkInstance createInstance(ExtensionSet const& requiredExts) {
    instanceCreateInfo.pApplicationInfo = &appInfo;
    instanceCreateInfo.enabledExtensionCount = enabledExtensionCount;
    instanceCreateInfo.ppEnabledExtensionNames = ppEnabledExtensions;
-    if (requiredExts.find(VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME) != requiredExts.end()) {
+    if (setContains(requiredExts, VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME)) {
        instanceCreateInfo.flags = VK_INSTANCE_CREATE_ENUMERATE_PORTABILITY_BIT_KHR;
    }

@@ -283,8 +285,8 @@ VkInstance createInstance(ExtensionSet const& requiredExts) {
 }

 VkDevice createLogicalDevice(VkPhysicalDevice physicalDevice,
-        const VkPhysicalDeviceFeatures& features, uint32_t graphicsQueueFamilyIndex,
-        const ExtensionSet& deviceExtensions) {
+        VkPhysicalDeviceFeatures const& features, uint32_t graphicsQueueFamilyIndex,
+        ExtensionSet const& deviceExtensions) {
    VkDevice device;
    VkDeviceQueueCreateInfo deviceQueueCreateInfo[1] = {};
    const float queuePriority[] = {1.0f};
@@ -292,9 +294,9 @@ VkDevice createLogicalDevice(VkPhysicalDevice physicalDevice,
    FixedCapacityVector<const char*> requestExtensions;
    requestExtensions.reserve(deviceExtensions.size() + 1);

-    // TODO:We don't really need this if we only ever expect headless swapchains.
+    // TODO: We don't really need this if we only ever expect headless swapchains.
    requestExtensions.push_back(VK_KHR_SWAPCHAIN_EXTENSION_NAME);
-    for (auto ext: deviceExtensions) {
+    for (auto const& ext: deviceExtensions) {
        requestExtensions.push_back(ext.data());
    }
    deviceQueueCreateInfo->sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;
@@ -323,12 +325,12 @@ VkDevice createLogicalDevice(VkPhysicalDevice physicalDevice,
            .imageViewFormatSwizzle = VK_TRUE,
            .mutableComparisonSamplers = VK_TRUE,
    };
-    if (deviceExtensions.find(VK_KHR_PORTABILITY_SUBSET_EXTENSION_NAME) != deviceExtensions.end()) {
+    if (setContains(deviceExtensions, VK_KHR_PORTABILITY_SUBSET_EXTENSION_NAME)) {
        deviceCreateInfo.pNext = &portability;
    }

    VkResult result = vkCreateDevice(physicalDevice, &deviceCreateInfo, VKALLOC, &device);
-    ASSERT_POSTCONDITION(result == VK_SUCCESS, "vkCreateDevice error.");
+    ASSERT_POSTCONDITION(result == VK_SUCCESS, "vkCreateDevice error=%d.", result);

    return device;
 }
@@ -342,16 +344,16 @@ std::tuple<ExtensionSet, ExtensionSet> pruneExtensions(VkPhysicalDevice device,

 #if FVK_ENABLED(FVK_DEBUG_DEBUG_UTILS)
    // debugUtils and debugMarkers extensions are used mutually exclusively.
-    if (newInstExts.find(VK_EXT_DEBUG_UTILS_EXTENSION_NAME) != newInstExts.end()
-            && newDeviceExts.find(VK_EXT_DEBUG_MARKER_EXTENSION_NAME) != newDeviceExts.end()) {
+    if (setContains(newInstExts, VK_EXT_DEBUG_UTILS_EXTENSION_NAME) &&
+            setContains(newInstExts, VK_EXT_DEBUG_MARKER_EXTENSION_NAME)) {
        newDeviceExts.erase(VK_EXT_DEBUG_MARKER_EXTENSION_NAME);
    }
 #endif

 #if FVK_ENABLED(FVK_DEBUG_VALIDATION)
    // debugMarker must also request debugReport the instance extension. So check if that's present.
-    if (newDeviceExts.find(VK_EXT_DEBUG_MARKER_EXTENSION_NAME) != newDeviceExts.end()
-            && newInstExts.find(VK_EXT_DEBUG_REPORT_EXTENSION_NAME) == newInstExts.end()) {
+    if (setContains(newInstExts, VK_EXT_DEBUG_MARKER_EXTENSION_NAME) &&
+            !setContains(newInstExts, VK_EXT_DEBUG_MARKER_EXTENSION_NAME)) {
        newDeviceExts.erase(VK_EXT_DEBUG_MARKER_EXTENSION_NAME);
    }
 #endif
@@ -557,6 +559,7 @@ struct VulkanPlatformPrivate {
    std::unordered_set<SwapChainPtr> mHeadlessSwapChains;

    bool mSharedContext = false;
+    bool mForceXCBSwapchain = false;
 };

 void VulkanPlatform::terminate() {
@@ -610,7 +613,25 @@ Driver* VulkanPlatform::createDriver(void* sharedContext,
    ExtensionSet instExts;
    // If using a shared context, we do not assume any extensions.
    if (!mImpl->mSharedContext) {
-        instExts = getInstanceExtensions();
+        // This constains instance extensions that are required for the platform, which includes
+        // swapchain surface extensions.
+        auto const& swapchainExts = getSwapchainInstanceExtensions();
+        instExts = getInstanceExtensions(swapchainExts);
+
+#if defined(FILAMENT_SUPPORTS_XCB) && defined(FILAMENT_SUPPORTS_XLIB)
+        // For the special case where we're on linux and both xcb and xlib are "required", then we
+        // check if the set of supported extensions contain both of them.  If only xcb is supported,
+        // we force XCB surface creation.  This workaround is needed for the default swiftshader
+        // build where only XCB is available.
+        if (setContains(swapchainExts, VK_KHR_XCB_SURFACE_EXTENSION_NAME) &&
+                setContains(swapchainExts, VK_KHR_XLIB_SURFACE_EXTENSION_NAME)) {
+            // Assume only XCB is left, then we force the XCB path in the swapchain creation.
+            mImpl->mForceXCBSwapchain = !setContains(instExts, VK_KHR_XLIB_SURFACE_EXTENSION_NAME);
+            assert_invariant(!mImpl->mForceXCBSwapchain ||
+                             setContains(instExts, VK_KHR_XCB_SURFACE_EXTENSION_NAME));
+        }
+#endif
+
        instExts.merge(getRequiredInstanceExtensions());
    }

@@ -672,10 +693,8 @@ Driver* VulkanPlatform::createDriver(void* sharedContext,
    assert_invariant(mImpl->mGraphicsQueue != VK_NULL_HANDLE);

    // Store the extension support in the context
-    context.mDebugUtilsSupported
-            = instExts.find(VK_EXT_DEBUG_UTILS_EXTENSION_NAME) != instExts.end();
-    context.mDebugMarkersSupported
-            = deviceExts.find(VK_EXT_DEBUG_MARKER_EXTENSION_NAME) != deviceExts.end();
+    context.mDebugUtilsSupported = setContains(instExts, VK_EXT_DEBUG_UTILS_EXTENSION_NAME);
+    context.mDebugMarkersSupported = setContains(deviceExts, VK_EXT_DEBUG_MARKER_EXTENSION_NAME);

 #ifdef NDEBUG
    // If we are in release build, we should not have turned on debug extensions
@@ -748,6 +767,10 @@ SwapChainPtr VulkanPlatform::createSwapChain(void* nativeWindow, uint64_t flags,
        return swapchain;
    }

+    if (mImpl->mForceXCBSwapchain) {
+        flags |= SWAP_CHAIN_CONFIG_ENABLE_XCB;
+    }
+
    auto [surface, fallbackExtent] = createVkSurfaceKHR(nativeWindow, mImpl->mInstance, flags);
    // The VulkanPlatformSurfaceSwapChain now `owns` the surface.
    VulkanPlatformSurfaceSwapChain* swapchain = new VulkanPlatformSurfaceSwapChain(mImpl->mContext,
--- a/filament/backend/src/vulkan/platform/VulkanPlatformAndroidLinuxWindows.cpp
+++ b/filament/backend/src/vulkan/platform/VulkanPlatformAndroidLinuxWindows.cpp
@@ -46,7 +46,7 @@
            uint32_t height;
        } wl;
    }// anonymous namespace
-#elif LINUX_OR_FREEBSD && defined(FILAMENT_SUPPORTS_X11)
+#elif defined(LINUX_OR_FREEBSD) && defined(FILAMENT_SUPPORTS_X11)
    // TODO: we should allow for headless on Linux explicitly. Right now this is the headless path
    // (with no FILAMENT_SUPPORTS_XCB or FILAMENT_SUPPORTS_XLIB).
    #include <dlfcn.h>
@@ -86,22 +86,23 @@ using namespace bluevk;

 namespace filament::backend {

-VulkanPlatform::ExtensionSet VulkanPlatform::getRequiredInstanceExtensions() {
-    VulkanPlatform::ExtensionSet ret;
-    #if defined(__ANDROID__)
-        ret.insert("VK_KHR_android_surface");
-    #elif defined(__linux__) && defined(FILAMENT_SUPPORTS_WAYLAND)
-        ret.insert("VK_KHR_wayland_surface");
-    #elif LINUX_OR_FREEBSD && defined(FILAMENT_SUPPORTS_X11)
-        #if defined(FILAMENT_SUPPORTS_XCB)
-            ret.insert("VK_KHR_xcb_surface");
-        #endif
-        #if defined(FILAMENT_SUPPORTS_XLIB)
-            ret.insert("VK_KHR_xlib_surface");
-        #endif
-    #elif defined(WIN32)
-        ret.insert("VK_KHR_win32_surface");
+VulkanPlatform::ExtensionSet VulkanPlatform::getSwapchainInstanceExtensions() {
+    VulkanPlatform::ExtensionSet const ret = {
+#if defined(__ANDROID__)
+        VK_KHR_ANDROID_SURFACE_EXTENSION_NAME,
+#elif defined(__linux__) && defined(FILAMENT_SUPPORTS_WAYLAND)
+        VK_KHR_WAYLAND_SURFACE_EXTENSION_NAME,
+#elif defined(LINUX_OR_FREEBSD) && defined(FILAMENT_SUPPORTS_X11)
+    #if defined(FILAMENT_SUPPORTS_XCB)
+        VK_KHR_XCB_SURFACE_EXTENSION_NAME,
    #endif
+    #if defined(FILAMENT_SUPPORTS_XLIB)
+        VK_KHR_XLIB_SURFACE_EXTENSION_NAME,
+    #endif
+#elif defined(WIN32)
+        VK_KHR_WIN32_SURFACE_EXTENSION_NAME,
+#endif
+    };
    return ret;
 }

@@ -138,7 +139,7 @@ VulkanPlatform::SurfaceBundle VulkanPlatform::createVkSurfaceKHR(void* nativeWin
        VkResult const result = vkCreateWaylandSurfaceKHR(instance, &createInfo, VKALLOC,
                (VkSurfaceKHR*) &surface);
        ASSERT_POSTCONDITION(result == VK_SUCCESS, "vkCreateWaylandSurfaceKHR error.");
-    #elif LINUX_OR_FREEBSD && defined(FILAMENT_SUPPORTS_X11)
+    #elif defined(LINUX_OR_FREEBSD) && defined(FILAMENT_SUPPORTS_X11)
        if (g_x11_vk.library == nullptr) {
            g_x11_vk.library = dlopen(LIBRARY_X11, RTLD_LOCAL | RTLD_NOW);
            ASSERT_PRECONDITION(g_x11_vk.library, "Unable to open X11 library.");
@@ -146,15 +147,11 @@ VulkanPlatform::SurfaceBundle VulkanPlatform::createVkSurfaceKHR(void* nativeWin
                g_x11_vk.xcbConnect = (XCB_CONNECT) dlsym(g_x11_vk.library, "xcb_connect");
                int screen;
                g_x11_vk.connection = g_x11_vk.xcbConnect(nullptr, &screen);
-                ASSERT_POSTCONDITION(vkCreateXcbSurfaceKHR,
-                        "Unable to load vkCreateXcbSurfaceKHR function.");
            #endif
            #if defined(FILAMENT_SUPPORTS_XLIB)
                g_x11_vk.openDisplay = (X11_OPEN_DISPLAY) dlsym(g_x11_vk.library, "XOpenDisplay");
                g_x11_vk.display = g_x11_vk.openDisplay(NULL);
                ASSERT_PRECONDITION(g_x11_vk.display, "Unable to open X11 display.");
-                ASSERT_POSTCONDITION(vkCreateXlibSurfaceKHR,
-                        "Unable to load vkCreateXlibSurfaceKHR function.");
            #endif
        }
        #if defined(FILAMENT_SUPPORTS_XCB) || defined(FILAMENT_SUPPORTS_XLIB)
@@ -167,6 +164,9 @@ VulkanPlatform::SurfaceBundle VulkanPlatform::createVkSurfaceKHR(void* nativeWin
                useXcb = true;
            #endif
            if (useXcb) {
+                ASSERT_POSTCONDITION(vkCreateXcbSurfaceKHR,
+                        "Unable to load vkCreateXcbSurfaceKHR function.");
+
                VkXcbSurfaceCreateInfoKHR const createInfo = {
                        .sType = VK_STRUCTURE_TYPE_XCB_SURFACE_CREATE_INFO_KHR,
                        .connection = g_x11_vk.connection,
@@ -179,6 +179,9 @@ VulkanPlatform::SurfaceBundle VulkanPlatform::createVkSurfaceKHR(void* nativeWin
        #endif
        #if defined(FILAMENT_SUPPORTS_XLIB)
            if (!useXcb) {
+                ASSERT_POSTCONDITION(vkCreateXlibSurfaceKHR,
+                        "Unable to load vkCreateXlibSurfaceKHR function.");
+
                VkXlibSurfaceCreateInfoKHR const createInfo = {
                        .sType = VK_STRUCTURE_TYPE_XLIB_SURFACE_CREATE_INFO_KHR,
                        .dpy = g_x11_vk.display,
--- a/filament/backend/src/vulkan/platform/VulkanPlatformApple.mm
+++ b/filament/backend/src/vulkan/platform/VulkanPlatformApple.mm
@@ -52,13 +52,14 @@ using namespace bluevk;

 namespace filament::backend {

-VulkanPlatform::ExtensionSet VulkanPlatform::getRequiredInstanceExtensions() {
-    ExtensionSet ret;
+VulkanPlatform::ExtensionSet VulkanPlatform::getSwapchainInstanceExtensions() {
+    ExtensionSet const ret = {
    #if defined(__APPLE__)
-        ret.insert("VK_MVK_macos_surface"); // TODO: replace with VK_EXT_metal_surface
-    #elif defined(IOS)
-        ret.insert("VK_MVK_ios_surface");
+        VK_MVK_MACOS_SURFACE_EXTENSION_NAME,  // TODO: replace with VK_EXT_metal_surface
+    #elif defined(IOS) && defined(METAL_AVAILABLE)
+        VK_MVK_IOS_SURFACE_EXTENSION_NAME,
    #endif
+    };
    return ret;
 }

--- a/filament/backend/test/BackendTest.cpp
+++ b/filament/backend/test/BackendTest.cpp
@@ -20,6 +20,7 @@

 #include "BackendTest.h"

+#include <utils/Log.h>
 #include <utils/Hash.h>

 #include <fstream>
@@ -149,50 +150,59 @@ void BackendTest::renderTriangle(Handle<HwRenderTarget> renderTarget,
 }

 void BackendTest::readPixelsAndAssertHash(const char* testName, size_t width, size_t height,
-        Handle<HwRenderTarget> rt, uint32_t expectedHash, bool exportScreenshot) {
-    void* buffer = calloc(1, width * height * 4);
+        Handle<HwRenderTarget> rt, uint32_t const expectedHash, bool const exportScreenshot) {
+    auto img = getRenderTargetRGB(rt, width, height);
+    uint32_t hash = computeImageHash(img);

-    struct Capture {
-        uint32_t expectedHash;
-        char* name;
-        bool exportScreenshot;
-        size_t width, height;
-    };
-    auto* c = new Capture();
-    c->expectedHash = expectedHash;
-    c->name = strdup(testName);
-    c->exportScreenshot = exportScreenshot;
-    c->width = width;
-    c->height = height;
-
-    PixelBufferDescriptor pbd(buffer, width * height * 4, PixelDataFormat::RGBA, PixelDataType::UBYTE,
-            1, 0, 0, width, [](void* buffer, size_t size, void* user) {
-                auto* c = (Capture*)user;
-
-                // Export a screenshot, if requested.
-                if (c->exportScreenshot) {
-#ifndef IOS
-                    LinearImage image(c->width, c->height, 4);
-                    image = toLinearWithAlpha<uint8_t>(c->width, c->height, c->width * 4,
-                            (uint8_t*) buffer);
-                    const std::string png = std::string(c->name) + ".png";
-                    std::ofstream outputStream(png.c_str(), std::ios::binary | std::ios::trunc);
-                    ImageEncoder::encode(outputStream, ImageEncoder::Format::PNG, image, "",
-                            png);
-#endif
-                }
-
-                // Hash the contents of the buffer and check that they match.
-                uint32_t hash = utils::hash::murmur3((const uint32_t*) buffer, size / 4, 0);
-                ASSERT_EQ(hash, c->expectedHash) << c->name << " failed: hashes do not match." << std::endl;
-
-                free(buffer);
-                free(c->name);
-                free(c);
-            }, (void*)c);
-    getDriverApi().readPixels(rt, 0, 0, width, height, std::move(pbd));
+    if (exportScreenshot) {
+        writeImage(img, width, height, utils::CString(testName));
+    }
+    ASSERT_EQ(hash, expectedHash) << testName << " failed: hashes do not match." << std::endl;
 }

+void BackendTest::writeImage(utils::FixedCapacityVector<uint8_t> img, size_t w, size_t h,
+        utils::CString const& fname) {
+    constexpr size_t MAX_FNAME_LEN = 50;
+    constexpr size_t FNAME_EXT_LEN = 4;
+    constexpr size_t TOTAL_LEN = MAX_FNAME_LEN + FNAME_EXT_LEN + 1;
+    char buf[TOTAL_LEN];
+
+    ASSERT_PRECONDITION(fname.size() <= MAX_FNAME_LEN, "File name %s is too long", fname.c_str());
+
+    snprintf(buf, TOTAL_LEN, "%s.png", fname.c_str());
+
+#ifndef IOS
+    LinearImage image(w, h, 4);
+    image = toLinearWithAlpha<uint8_t>(w, h, w * 4, img.data());
+    std::ofstream pngstrm(buf, std::ios::binary | std::ios::trunc);
+    ImageEncoder::encode(pngstrm, ImageEncoder::Format::PNG, image, "", buf);
+#endif
+}
+
+utils::FixedCapacityVector<uint8_t> BackendTest::getRenderTarget(
+        Handle<HwRenderTarget> rt, size_t width, size_t height, PixelDataFormat format,
+        PixelDataType dataType) {
+    auto& api = getDriverApi();
+    size_t const size = width * height * 4;
+    utils::FixedCapacityVector<uint8_t> result(size);
+    PixelBufferDescriptor pb(result.data(), size, format, dataType);
+    api.readPixels(rt, 0, 0, width, height, std::move(pb));
+    flushAndWait();
+
+    return result;
+}
+
+uint32_t BackendTest::computeImageHash(utils::FixedCapacityVector<uint8_t> const& img) {
+    return utils::hash::murmur3((uint32_t*) img.data(), img.size() / 4, 0);
+}
+
+utils::FixedCapacityVector<uint8_t> BackendTest::getRenderTargetRGB(
+        Handle<HwRenderTarget> rt, size_t width, size_t height) {
+    return getRenderTarget(rt, width, height, PixelDataFormat::RGBA,
+            PixelDataType::UBYTE);
+}
+
+
 class Environment : public ::testing::Environment {
 public:
    virtual void SetUp() override {
--- a/filament/backend/test/BackendTest.h
+++ b/filament/backend/test/BackendTest.h
@@ -67,6 +67,17 @@ protected:
    filament::backend::Driver& getDriver() { return *driver; }

 private:
+    void writeImage(utils::FixedCapacityVector<uint8_t> img, size_t w, size_t h,
+            utils::CString const& fname);
+    utils::FixedCapacityVector<uint8_t> getRenderTarget(
+            filament::backend::Handle<filament::backend::HwRenderTarget> rt, size_t width,
+            size_t height, filament::backend::PixelDataFormat format,
+            filament::backend::PixelDataType dataType);
+    uint32_t computeImageHash(utils::FixedCapacityVector<uint8_t> const& img);
+
+    utils::FixedCapacityVector<uint8_t> getRenderTargetRGB(
+            filament::backend::Handle<filament::backend::HwRenderTarget> rt, size_t width,
+            size_t height);

    filament::backend::Driver* driver = nullptr;
    filament::backend::CommandBufferQueue commandBufferQueue;
--- a/filament/backend/test/test_Blit.cpp
+++ b/filament/backend/test/test_Blit.cpp
@@ -60,36 +60,6 @@ struct MaterialParams {
    float4 scale;
 };

-struct ScreenshotParams {
-    int width;
-    int height;
-    const char* filename;
-    uint32_t pixelHashResult;
-};
-
-#ifdef IOS
-static void dumpScreenshot(DriverApi& dapi, Handle<HwRenderTarget> rt, ScreenshotParams* params) {}
-#else
-static void dumpScreenshot(DriverApi& dapi, Handle<HwRenderTarget> rt, ScreenshotParams* params) {
-    using namespace image;
-    const size_t size = params->width * params->height * 4;
-    void* buffer = calloc(1, size);
-    auto cb = [](void* buffer, size_t size, void* user) {
-        ScreenshotParams* params = (ScreenshotParams*) user;
-        int w = params->width, h = params->height;
-        const uint32_t* texels = (uint32_t*) buffer;
-        params->pixelHashResult = utils::hash::murmur3(texels, size / 4, 0);
-        LinearImage image(w, h, 4);
-        image = toLinearWithAlpha<uint8_t>(w, h, w * 4, (uint8_t*) buffer);
-        std::ofstream pngstrm(params->filename, std::ios::binary | std::ios::trunc);
-        ImageEncoder::encode(pngstrm, ImageEncoder::Format::PNG, image, "", params->filename);
-    };
-    PixelBufferDescriptor pb(buffer, size, PixelDataFormat::RGBA, PixelDataType::UBYTE, cb,
-            (void*) params);
-    dapi.readPixels(rt, 0, 0, params->width, params->height, std::move(pb));
-}
-#endif
-
 static void uploadUniforms(DriverApi& dapi, Handle<HwBufferObject> ubh, MaterialParams params) {
    MaterialParams* tmp = new MaterialParams(params);
    auto cb = [](void* buffer, size_t size, void* user) {
@@ -243,21 +213,12 @@ TEST_F(BackendTest, ColorMagnify) {
    api.endFrame(0);

    // Grab a screenshot.
-    ScreenshotParams params { kDstTexWidth, kDstTexHeight, "ColorMagnify.png" };
    api.beginFrame(0, 0, 0);
-    dumpScreenshot(api, dstRenderTargets[0], &params);
-    api.commit(swapChain);
+    constexpr uint32_t expected = 0x410bdd31;
+    readPixelsAndAssertHash("ColorMagnify", kDstTexWidth, kDstTexHeight, dstRenderTargets[0],
+            expected, true);
    api.endFrame(0);
-
-    // Wait for the ReadPixels result to come back.
-    api.finish();
-    executeCommands();
-    getDriver().purge();
-
-    // Check if the image matches perfectly to our golden run.
-    const uint32_t expected = 0x410bdd31;
-    printf("Computed hash is 0x%8.8x, Expected 0x%8.8x\n", params.pixelHashResult, expected);
-    EXPECT_TRUE(params.pixelHashResult == expected);
+    flushAndWait();

    // Cleanup.
    api.destroyTexture(srcTexture);
@@ -315,17 +276,15 @@ TEST_F(BackendTest, ColorMinify) {
            SamplerMagFilter::LINEAR);

    // Grab a screenshot.
-    ScreenshotParams params { kDstTexWidth, kDstTexHeight, "ColorMinify.png" };
-    dumpScreenshot(api, dstRenderTargets[0], &params);
+    api.beginFrame(0, 0, 0);
+    constexpr uint32_t expected = 0xf3d9c53f;
+    readPixelsAndAssertHash("ColorMinify", kDstTexWidth, kDstTexHeight, dstRenderTargets[0],
+            expected, true);

-    // Wait for the ReadPixels result to come back.
+    api.commit(swapChain);
+    api.endFrame(0);
    flushAndWait();

-    // Check if the image matches perfectly to our golden run.
-    const uint32_t expected = 0xf3d9c53f;
-    printf("Computed hash is 0x%8.8x, Expected 0x%8.8x\n", params.pixelHashResult, expected);
-    EXPECT_TRUE(params.pixelHashResult == expected);
-
    // Cleanup.
    api.destroyTexture(srcTexture);
    api.destroyTexture(dstTexture);
@@ -416,17 +375,13 @@ TEST_F(BackendTest, ColorResolve) {
            SamplerMagFilter::NEAREST);

    // Grab a screenshot.
-    ScreenshotParams sparams{ kDstTexWidth, kDstTexHeight, "ColorResolve.png" };
-    dumpScreenshot(api, dstRenderTarget, &sparams);
-
-    // Wait for the ReadPixels result to come back.
+    api.beginFrame(0, 0, 0);
+    constexpr uint32_t expected = 0xebfac2ef;
+    readPixelsAndAssertHash("ColorResolve", kDstTexWidth, kDstTexHeight, dstRenderTarget,
+            expected, true);
+    api.endFrame(0);
    flushAndWait();

-    // Check if the image matches perfectly to our golden run.
-    const uint32_t expected = 0xebfac2ef;
-    printf("Computed hash is 0x%8.8x, Expected 0x%8.8x\n", sparams.pixelHashResult, expected);
-    EXPECT_TRUE(sparams.pixelHashResult == expected);
-
    // Cleanup.
    api.destroyBufferObject(ubuffer);
    api.destroyProgram(program);
@@ -489,21 +444,12 @@ TEST_F(BackendTest, Blit2DTextureArray) {
    api.endFrame(0);

    // Grab a screenshot.
-    ScreenshotParams params { kDstTexWidth, kDstTexHeight, "Blit2DTextureArray.png" };
    api.beginFrame(0, 0, 0);
-    dumpScreenshot(api, dstRenderTarget, &params);
-    api.commit(swapChain);
+    constexpr uint32_t expected = 0x8de7d55b;
+    readPixelsAndAssertHash("Blit2DTextureArray", kDstTexWidth, kDstTexHeight, dstRenderTarget,
+            expected, true);
    api.endFrame(0);
-
-    // Wait for the ReadPixels result to come back.
-    api.finish();
-    executeCommands();
-    getDriver().purge();
-
-    // Check if the image matches perfectly to our golden run.
-    const uint32_t expected = 0x8de7d55b;
-    printf("Computed hash is 0x%8.8x, Expected 0x%8.8x\n", params.pixelHashResult, expected);
-    EXPECT_TRUE(params.pixelHashResult == expected);
+    flushAndWait();

    // Cleanup.
    api.destroyTexture(srcTexture);
@@ -578,28 +524,17 @@ TEST_F(BackendTest, BlitRegion) {
    api.commit(swapChain);
    api.endFrame(0);

-    // Grab a screenshot.
-    ScreenshotParams params { kDstTexWidth, kDstTexHeight, "BlitRegion.png" };
-    api.beginFrame(0, 0, 0);
-    dumpScreenshot(api, dstRenderTarget, &params);
-    api.commit(swapChain);
-    api.endFrame(0);
-
-    // Wait for the ReadPixels result to come back.
-    api.finish();
-    executeCommands();
-    getDriver().purge();
-
    // Check if the image matches perfectly to our golden run.
-    //
    // TODO: for some reason, this test has very, very slight (as in one pixel) differences between
    // OpenGL and Metal. So disable golden checking for now.
    // Use the compare tool from ImageMagick to see visual differences:
    // compare -verbose -metric mae BlitRegion_Metal.png BlitRegion_OpenGL.png difference.png
-    //
-    // const uint32_t expected = 0x74fa34ed;
-    // printf("Computed hash is 0x%8.8x, Expected 0x%8.8x\n", params.pixelHashResult, expected);
-    // EXPECT_TRUE(params.pixelHashResult == expected);
+    // api.beginFrame(0, 0, 0);
+    // constexpr uint32_t expected = 0x74fa34ed;
+    // readPixelsAndAssertHash("BlitRegion", kDstTexWidth, kDstTexHeight, dstRenderTarget,
+    //         expected, true);
+    // api.endFrame(0);
+    // flushAndWait();

    // Cleanup.
    api.destroyTexture(srcTexture);
@@ -655,23 +590,22 @@ TEST_F(BackendTest, BlitRegionToSwapChain) {
        .height = kDstTexHeight - 10,
    };

-    api.beginFrame(0, 0, 0);
-
    api.blitDEPRECATED(TargetBufferFlags::COLOR0, dstRenderTarget,
            dstRect, srcRenderTargets[srcLevel],
            srcRect, SamplerMagFilter::LINEAR);

-    ScreenshotParams params { kDstTexWidth, kDstTexHeight, "BlitRegionToSwapChain.png" };
-    dumpScreenshot(api, dstRenderTarget, &params);
-
+    // Push through an empty frame to allow the texture to upload and the blit to execute.
+    api.beginFrame(0, 0, 0);
    api.commit(swapChain);
-
    api.endFrame(0);

-    // Wait for the ReadPixels result to come back.
-    api.finish();
-    executeCommands();
-    getDriver().purge();
+    // Grab a screenshot.
+    api.beginFrame(0, 0, 0);
+    constexpr uint32_t expected = 0xebfac2ef;
+    readPixelsAndAssertHash("BlitRegionToSwapChain", kDstTexWidth, kDstTexHeight, dstRenderTarget,
+            expected, true);
+    api.endFrame(0);
+    flushAndWait();

    // Cleanup.
    api.destroyTexture(srcTexture);
--- a/filament/backend/test/test_Callbacks.cpp
+++ b/filament/backend/test/test_Callbacks.cpp
@@ -0,0 +1,122 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "BackendTest.h"
+
+using namespace filament;
+using namespace filament::backend;
+
+namespace test {
+
+TEST_F(BackendTest, FrameScheduledCallback) {
+    auto& api = getDriverApi();
+
+    // Create a SwapChain.
+    // In order for the frameScheduledCallback to be called, this must be a real SwapChain (not
+    // headless) so we obtain a drawable.
+    auto swapChain = createSwapChain();
+
+    Handle<HwRenderTarget> renderTarget = api.createDefaultRenderTarget();
+
+    int callbackCountA = 0;
+    api.setFrameScheduledCallback(swapChain, nullptr, [&callbackCountA](PresentCallable callable) {
+        callable();
+        callbackCountA++;
+    });
+
+    // Render the first frame.
+    api.makeCurrent(swapChain, swapChain);
+    api.beginFrame(0, 0, 0);
+    api.beginRenderPass(renderTarget, {});
+    api.endRenderPass(0);
+    api.commit(swapChain);
+    api.endFrame(0);
+
+    // Render the next frame. The same callback should be called.
+    api.makeCurrent(swapChain, swapChain);
+    api.beginFrame(0, 0, 0);
+    api.beginRenderPass(renderTarget, {});
+    api.endRenderPass(0);
+    api.commit(swapChain);
+    api.endFrame(0);
+
+    // Now switch out the callback.
+    int callbackCountB = 0;
+    api.setFrameScheduledCallback(swapChain, nullptr, [&callbackCountB](PresentCallable callable) {
+        callable();
+        callbackCountB++;
+    });
+
+    // Render one final frame.
+    api.makeCurrent(swapChain, swapChain);
+    api.beginFrame(0, 0, 0);
+    api.beginRenderPass(renderTarget, {});
+    api.endRenderPass(0);
+    api.commit(swapChain);
+    api.endFrame(0);
+
+    api.finish();
+
+    executeCommands();
+    getDriver().purge();
+
+    EXPECT_EQ(callbackCountA, 2);
+    EXPECT_EQ(callbackCountB, 1);
+}
+
+TEST_F(BackendTest, FrameCompletedCallback) {
+    auto& api = getDriverApi();
+
+    // Create a SwapChain.
+    auto swapChain = api.createSwapChainHeadless(256, 256, 0);
+
+    int callbackCountA = 0;
+    api.setFrameCompletedCallback(swapChain, nullptr,
+            [&callbackCountA]() { callbackCountA++; });
+
+    // Render the first frame.
+    api.makeCurrent(swapChain, swapChain);
+    api.beginFrame(0, 0, 0);
+    api.commit(swapChain);
+    api.endFrame(0);
+
+    // Render the next frame. The same callback should be called.
+    api.makeCurrent(swapChain, swapChain);
+    api.beginFrame(0, 0, 0);
+    api.commit(swapChain);
+    api.endFrame(0);
+
+    // Now switch out the callback.
+    int callbackCountB = 0;
+    api.setFrameCompletedCallback(swapChain, nullptr,
+            [&callbackCountB]() { callbackCountB++; });
+
+    // Render one final frame.
+    api.makeCurrent(swapChain, swapChain);
+    api.beginFrame(0, 0, 0);
+    api.commit(swapChain);
+    api.endFrame(0);
+
+    api.finish();
+
+    executeCommands();
+    getDriver().purge();
+
+    EXPECT_EQ(callbackCountA, 2);
+    EXPECT_EQ(callbackCountB, 1);
+}
+
+} // namespace test
--- a/filament/backend/test/test_FeedbackLoops.cpp
+++ b/filament/backend/test/test_FeedbackLoops.cpp
@@ -16,6 +16,7 @@

 #include "BackendTest.h"

+#include "BackendTestUtils.h"
 #include "ShaderGenerator.h"
 #include "TrianglePrimitive.h"

@@ -64,8 +65,6 @@ void main() {
    fragColor = textureLod(test_tex, uv, params.sourceLevel);
 })";

-static uint32_t sPixelHashResult = 0;
-
 // Selecting a NPOT texture size seems to exacerbate the bug seen with Intel GPU's.
 // Note that Filament uses a higher precision format (R11F_G11F_B10F) but this does not seem
 // necessary to trigger the bug.
@@ -99,30 +98,13 @@ static void uploadUniforms(DriverApi& dapi, Handle<HwBufferObject> ubh, Material
    dapi.updateBufferObject(ubh, std::move(bd), 0);
 }

-static void dumpScreenshot(DriverApi& dapi, Handle<HwRenderTarget> rt) {
-    const size_t size = kTexWidth * kTexHeight * 4;
-    void* buffer = calloc(1, size);
-    auto cb = [](void* buffer, size_t size, void* user) {
-        int w = kTexWidth, h = kTexHeight;
-        const uint32_t* texels = (uint32_t*) buffer;
-        sPixelHashResult = utils::hash::murmur3(texels, size / 4, 0);
-        #ifndef IOS
-        LinearImage image(w, h, 4);
-        image = toLinearWithAlpha<uint8_t>(w, h, w * 4, (uint8_t*) buffer);
-        std::ofstream pngstrm("feedback.png", std::ios::binary | std::ios::trunc);
-        ImageEncoder::encode(pngstrm, ImageEncoder::Format::PNG, image, "", "feedback.png");
-        #endif
-        free(buffer);
-    };
-    PixelBufferDescriptor pb(buffer, size, PixelDataFormat::RGBA, PixelDataType::UBYTE, cb);
-    dapi.readPixels(rt, 0, 0, kTexWidth, kTexHeight, std::move(pb));
-}
-
 // TODO: This test needs work to get Metal and OpenGL to agree on results.
 // The problems are caused by both uploading and rendering into the same texture, since the OpenGL
 // backend's readPixels does not work correctly with textures that have image data uploaded.
 TEST_F(BackendTest, FeedbackLoops) {
    auto& api = getDriverApi();
+    auto& driver = getDriver();
+    uint32_t pixelHashResult = 0;

    // The test is executed within this block scope to force destructors to run before
    // executeCommands().
@@ -147,7 +129,7 @@ TEST_F(BackendTest, FeedbackLoops) {
            program = api.createProgram(std::move(prog));
        }

-        TrianglePrimitive const triangle(getDriverApi());
+        TrianglePrimitive const triangle(api);

        // Create a texture.
        auto usage = TextureUsage::COLOR_ATTACHMENT | TextureUsage::SAMPLEABLE;
@@ -211,8 +193,8 @@ TEST_F(BackendTest, FeedbackLoops) {
                const uint32_t sourceLevel = targetLevel - 1;
                params.viewport.width = kTexWidth >> targetLevel;
                params.viewport.height = kTexHeight >> targetLevel;
-                getDriverApi().setMinMaxLevels(texture, sourceLevel, sourceLevel);
-                uploadUniforms(getDriverApi(), ubuffer, {
+                api.setMinMaxLevels(texture, sourceLevel, sourceLevel);
+                uploadUniforms(api, ubuffer, {
                    .fbWidth = float(params.viewport.width),
                    .fbHeight = float(params.viewport.height),
                    .sourceLevel = float(sourceLevel),
@@ -230,8 +212,8 @@ TEST_F(BackendTest, FeedbackLoops) {
                const uint32_t sourceLevel = targetLevel + 1;
                params.viewport.width = kTexWidth >> targetLevel;
                params.viewport.height = kTexHeight >> targetLevel;
-                getDriverApi().setMinMaxLevels(texture, sourceLevel, sourceLevel);
-                uploadUniforms(getDriverApi(), ubuffer, {
+                api.setMinMaxLevels(texture, sourceLevel, sourceLevel);
+                uploadUniforms(api, ubuffer, {
                    .fbWidth = float(params.viewport.width),
                    .fbHeight = float(params.viewport.height),
                    .sourceLevel = float(sourceLevel),
@@ -241,14 +223,16 @@ TEST_F(BackendTest, FeedbackLoops) {
                api.endRenderPass();
            }

-            getDriverApi().setMinMaxLevels(texture, 0, 0x7f);
+            api.setMinMaxLevels(texture, 0, 0x7f);

            // Read back the render target corresponding to the base level.
            //
            // NOTE: Calling glReadPixels on any miplevel other than the base level
            // seems to be un-reliable on some GPU's.
            if (frame == kNumFrames - 1) {
-                dumpScreenshot(api, renderTargets[0]);
+                constexpr uint32_t expected = 0x70695aa1;
+                readPixelsAndAssertHash("feedback", kTexWidth, kTexHeight, renderTargets[0],
+                        expected, true);
            }

            api.flush();
@@ -256,7 +240,7 @@ TEST_F(BackendTest, FeedbackLoops) {
            api.endFrame(0);
            api.finish();
            executeCommands();
-            getDriver().purge();
+            driver.purge();
        }

        api.destroyProgram(program);
@@ -264,10 +248,6 @@ TEST_F(BackendTest, FeedbackLoops) {
        api.destroyTexture(texture);
        for (auto rt : renderTargets)  api.destroyRenderTarget(rt);
    }
-
-    const uint32_t expected = 0x70695aa1;
-    printf("Computed hash is 0x%8.8x, Expected 0x%8.8x\n", sPixelHashResult, expected);
-    EXPECT_TRUE(sPixelHashResult == expected);
 }

 } // namespace test
--- a/filament/src/details/SwapChain.cpp
+++ b/filament/src/details/SwapChain.cpp
@@ -79,24 +79,11 @@ bool FSwapChain::isFrameScheduledCallbackSet() const noexcept {
    return mFrameScheduledCallbackIsSet;
 }

-void FSwapChain::setFrameCompletedCallback(backend::CallbackHandler* handler,
-                utils::Invocable<void(SwapChain*)>&& callback) noexcept {
-    struct Callback {
-        utils::Invocable<void(SwapChain*)> f;
-        SwapChain* s;
-        static void func(void* user) {
-            auto* const c = reinterpret_cast<Callback*>(user);
-            c->f(c->s);
-            delete c;
-        }
-    };
-    if (callback) {
-        auto* const user = new(std::nothrow) Callback{ std::move(callback), this };
-        mEngine.getDriverApi().setFrameCompletedCallback(
-                mHwSwapChain, handler, &Callback::func, static_cast<void*>(user));
-    } else {
-        mEngine.getDriverApi().setFrameCompletedCallback(mHwSwapChain, nullptr, nullptr, nullptr);
-    }
+void FSwapChain::setFrameCompletedCallback(
+        backend::CallbackHandler* handler, FrameCompletedCallback&& callback) noexcept {
+    using namespace std::placeholders;
+    auto boundCallback = std::bind(std::move(callback), this);
+    mEngine.getDriverApi().setFrameCompletedCallback(mHwSwapChain, handler, std::move(boundCallback));
 }

 bool FSwapChain::isSRGBSwapChainSupported(FEngine& engine) noexcept {
--- a/libs/utils/include/utils/FixedCapacityVector.h
+++ b/libs/utils/include/utils/FixedCapacityVector.h
@@ -299,6 +299,16 @@ public:
        }
    }

+    UTILS_NOINLINE
+    void shrink_to_fit() {
+        if (size() < capacity()) {
+            FixedCapacityVector t(construct_with_capacity, size(), allocator());
+            t.mSize = size();
+            std::uninitialized_move(begin(), end(), t.begin());
+            this->swap(t);
+        }
+    }
+
 private:
    enum construct_with_capacity_tag{ construct_with_capacity };

--- a/libs/utils/include/utils/bitset.h
+++ b/libs/utils/include/utils/bitset.h
@@ -60,6 +60,11 @@ public:
        std::fill(std::begin(storage), std::end(storage), 0);
    }

+    template<typename U, typename = typename std::enable_if_t<N == 1, U>>
+    explicit bitset(U value) noexcept {
+        storage[0] = value;
+    }
+
    T getBitsAt(size_t n) const noexcept {
        assert_invariant(n<N);
        return storage[n];
@@ -94,6 +99,8 @@ public:

    size_t size() const noexcept { return N * BITS_PER_WORD; }

+    bool empty() const noexcept { return none(); }
+
    bool test(size_t bit) const noexcept { return operator[](bit); }

    void set(size_t b) noexcept {
@@ -117,11 +124,14 @@ public:
        storage[b / BITS_PER_WORD] ^= T(1) << (b % BITS_PER_WORD);
    }

-
    void reset() noexcept {
        std::fill(std::begin(storage), std::end(storage), 0);
    }

+    void clear() noexcept {
+        reset();
+    }
+
    bool operator[](size_t b) const noexcept {
        assert_invariant(b / BITS_PER_WORD < N);
        return bool(storage[b / BITS_PER_WORD] & (T(1) << (b % BITS_PER_WORD)));
Author	SHA1	Message	Date
Powei Feng	3e32e6cf2a	backend-test: centralize read pixel logic	2024-05-16 15:08:56 -07:00
Ben Doherty	1d4f1fe71f	Metal, fix callbacks being called only once (#7856 )	2024-05-15 10:50:10 -07:00
Mathias Agopian	c93aa4c90d	minor libutils improvements	2024-05-14 13:22:38 -07:00
Mathias Agopian	499939ed3c	backend: bindPipeline now takes const&	2024-05-14 13:21:38 -07:00
Mathias Agopian	6be97ee01d	backend: zero-cost ES2 draw() we use a different hook for the draw() call when on an ES2 context, this eliminates completely the overhead of supporting ES2 for the draw call. draw calls are expected to be the most common calls.	2024-05-14 13:21:24 -07:00
Powei Feng	7267696cbf	vk: fix dynamic scissor validation error (#7853 )	2024-05-14 19:08:50 +00:00
Powei Feng	85eb724a90	Reduce explicit swiftshader paths (#7848 ) - Use custom ICD path to enable Swiftshader instead of specifying direct path to the lib. - Remove unused `swiftshader` directory in `build` - Remove swiftshader options in `build.sh` and cmakefiles - Change BUILD.md - Correctly handle XCB-only swapchain surface in VulkanPlatform for swiftshader. - Refactor `VulkanPlatform::ExtensionSet` so that `utils::CString` is used instead of string_view, so that we don't get into tricky lifetime issues with `const char*`	2024-05-14 17:40:54 +00:00
Mathias Agopian	6dd6db89d5	align android libraries to 16 KiB	2024-05-13 23:14:32 -07:00
Mathias Agopian	c76f67c139	fix typo checking FILAMENT_ENABLE_MATDBG this macro must be checked with #if not #ifdef	2024-05-13 23:14:13 -07:00