Add Android sample app (#181)

* Add Android sample app

It’s a simple rotating triangle but provides a good overview of how to use Filament on Android

* Remove unnecessary files

README.md

@@ -101,6 +101,8 @@ Many other features have been either prototyped or planned:
 
 - `filament`:                Filament engine and its supporting libraries and tools
   - `android`:               Android libraries and projects
+    - `filament-android`:    Filament library (AAR) for Android
+    - `samples`:             Android-specific Filament samples
   - `art`:                   Source for various artworks (logos, PDF manuals, etc.)
   - `assets`:                3D assets to use with sample applications
   - `build`:                 CMake build scripts
@@ -808,6 +810,8 @@ these methods on `FilamentCanvas` or `FilamentPanel`.
 
 ### Android
 
+See `android/samples` for examples of how to use Filament on Android.
+
 You must always first initialize Filament by calling `Filament.init()`.
 
 Rendering with Filament on Android is similar to rendering from native code (the APIs are largely

android/filament-android/.gitignore

@@ -3,6 +3,7 @@
 /local.properties
 /.idea/workspace.xml
 /.idea/libraries
+/.idea/caches
 /.idea/gradle.xml
 .DS_Store
 /build

android/filament-android/.idea/misc.xml

@@ -5,11 +5,12 @@
     <option name="myDefaultNotNull" value="android.support.annotation.NonNull" />
     <option name="myNullables">
       <value>
-        <list size="4">
+        <list size="5">
           <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.Nullable" />
           <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nullable" />
-          <item index="2" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.Nullable" />
-          <item index="3" class="java.lang.String" itemvalue="android.support.annotation.Nullable" />
+          <item index="2" class="java.lang.String" itemvalue="javax.annotation.CheckForNull" />
+          <item index="3" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.Nullable" />
+          <item index="4" class="java.lang.String" itemvalue="android.support.annotation.Nullable" />
         </list>
       </value>
     </option>

android/filament-android/build.gradle

@@ -12,7 +12,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.1.3'
+        classpath 'com.android.tools.build:gradle:3.1.4'
     }
 }
 
@@ -23,6 +23,9 @@ allprojects {
     }
 }
 
+group = "com.google.android.filament"
+version = "0.1"
+
 apply plugin: 'com.android.library'
 
 def filament_path = file("../../out/android-release/filament").absolutePath
@@ -83,6 +86,3 @@ dependencies {
     implementation fileTree(include: ['*.jar'], dir: 'libs')
     implementation 'com.android.support:support-annotations:27.1.1'
 }
-
-group = "com.google.android.filament"
-version = "0.1"

android/filament-android/gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Sun Aug 05 15:12:47 PDT 2018
+#Tue Aug 28 15:45:13 PDT 2018
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.6-all.zip

android/filament-android/settings.gradle

@@ -0,0 +1 @@
+rootProject.name = 'filament-android'

android/filament-android/src/main/cpp/View.cpp

@@ -21,8 +21,8 @@
 using namespace filament;
 
 extern "C" JNIEXPORT void JNICALL
-Java_com_google_android_filament_View_nSetName(JNIEnv* env, jclass, jlong nativeView,
-        jstring name_) {
+Java_com_google_android_filament_View_nSetName(JNIEnv* env, jclass,
+        jlong nativeView, jstring name_) {
     View* view = (View*) nativeView;
     const char* name = env->GetStringUTFChars(name_, 0);
     view->setName(name);
@@ -30,38 +30,39 @@ Java_com_google_android_filament_View_nSetName(JNIEnv* env, jclass, jlong native
 }
 
 extern "C" JNIEXPORT void JNICALL
-Java_com_google_android_filament_View_nSetScene(JNIEnv*, jclass, jlong nativeView,
-        jlong nativeScene) {
+Java_com_google_android_filament_View_nSetScene(JNIEnv*, jclass,
+        jlong nativeView, jlong nativeScene) {
     View* view = (View*) nativeView;
     Scene* scene = (Scene*) nativeScene;
     view->setScene(scene);
 }
 
 extern "C" JNIEXPORT void JNICALL
-Java_com_google_android_filament_View_nSetCamera(JNIEnv*, jclass, jlong nativeView,
-        jlong nativeCamera) {
+Java_com_google_android_filament_View_nSetCamera(JNIEnv*, jclass,
+        jlong nativeView, jlong nativeCamera) {
     View* view = (View*) nativeView;
     Camera* camera = (Camera*) nativeCamera;
     view->setCamera(camera);
 }
 
 extern "C" JNIEXPORT void JNICALL
-Java_com_google_android_filament_View_nSetViewport(JNIEnv*, jclass, jlong nativeView,
-        jint left, jint bottom, jint width, jint height) {
+Java_com_google_android_filament_View_nSetViewport(JNIEnv*, jclass,
+        jlong nativeView, jint left, jint bottom, jint width, jint height) {
     View* view = (View*) nativeView;
     view->setViewport({left, bottom, (uint32_t) width, (uint32_t) height});
 }
 
 extern "C" JNIEXPORT void JNICALL
-Java_com_google_android_filament_View_nSetClearColor(JNIEnv*, jclass, jlong nativeView,
+Java_com_google_android_filament_View_nSetClearColor(JNIEnv*, jclass,
+        jlong nativeView,
         jfloat linearR, jfloat linearG, jfloat linearB, jfloat linearA) {
     View* view = (View*) nativeView;
     view->setClearColor({linearR, linearG, linearB, linearA});
 }
 
 extern "C" JNIEXPORT void JNICALL
-Java_com_google_android_filament_View_nGetClearColor(JNIEnv* env, jclass, jlong nativeView,
-        jfloatArray out_) {
+Java_com_google_android_filament_View_nGetClearColor(JNIEnv* env, jclass,
+        jlong nativeView, jfloatArray out_) {
     View* view = (View*) nativeView;
     jfloat* out = env->GetFloatArrayElements(out_, NULL);
     auto linearColor = view->getClearColor();
@@ -73,35 +74,36 @@ Java_com_google_android_filament_View_nGetClearColor(JNIEnv* env, jclass, jlong
 }
 
 extern "C" JNIEXPORT void JNICALL
-Java_com_google_android_filament_View_nSetClearTargets(JNIEnv*, jclass, jlong nativeView,
-        jboolean color, jboolean depth, jboolean stencil) {
+Java_com_google_android_filament_View_nSetClearTargets(JNIEnv*, jclass,
+        jlong nativeView, jboolean color, jboolean depth, jboolean stencil) {
     View* view = (View*) nativeView;
     view->setClearTargets(color, depth, stencil);
 }
 
 extern "C" JNIEXPORT void JNICALL
-Java_com_google_android_filament_View_nSetVisibleLayers(JNIEnv*, jclass, jlong nativeView,
-        jint select, jint value) {
+Java_com_google_android_filament_View_nSetVisibleLayers(JNIEnv*, jclass,
+        jlong nativeView, jint select, jint value) {
     View* view = (View*) nativeView;
     view->setVisibleLayers((uint8_t) select, (uint8_t) value);
 }
 
 extern "C" JNIEXPORT void JNICALL
-Java_com_google_android_filament_View_nSetShadowsEnabled(JNIEnv*, jclass, jlong nativeView,
-        jboolean enabled) {
+Java_com_google_android_filament_View_nSetShadowsEnabled(JNIEnv*, jclass,
+        jlong nativeView, jboolean enabled) {
     View* view = (View*) nativeView;
     view->setShadowsEnabled(enabled);
 }
 
 extern "C" JNIEXPORT void JNICALL
-Java_com_google_android_filament_View_nSetSampleCount(JNIEnv*, jclass, jlong nativeView,
-        jint count) {
+Java_com_google_android_filament_View_nSetSampleCount(JNIEnv*, jclass,
+        jlong nativeView, jint count) {
     View* view = (View*) nativeView;
     view->setSampleCount((uint8_t) count);
 }
 
 extern "C" JNIEXPORT jint JNICALL
-Java_com_google_android_filament_View_nGetSampleCount(JNIEnv*, jclass, jlong nativeView) {
+Java_com_google_android_filament_View_nGetSampleCount(JNIEnv*, jclass,
+        jlong nativeView) {
     View* view = (View*) nativeView;
     return view->getSampleCount();
 }
@@ -114,14 +116,15 @@ Java_com_google_android_filament_View_nSetAntiAliasing(JNIEnv*, jclass,
 }
 
 extern "C" JNIEXPORT jint JNICALL
-Java_com_google_android_filament_View_nGetAntiAliasing(JNIEnv*, jclass, jlong nativeView) {
+Java_com_google_android_filament_View_nGetAntiAliasing(JNIEnv*, jclass,
+        jlong nativeView) {
     View* view = (View*) nativeView;
     return (jint)view->getAntiAliasing();
 }
 
 extern "C" JNIEXPORT void JNICALL
-Java_com_google_android_filament_View_nSetDynamicResolutionOptions(JNIEnv *env, jclass,
-        jlong nativeView, jboolean enabled, jboolean homogeneousScaling,
+Java_com_google_android_filament_View_nSetDynamicResolutionOptions(JNIEnv*,
+        jclass, jlong nativeView, jboolean enabled, jboolean homogeneousScaling,
         jfloat targetFrameTimeMilli, jfloat headRoomRatio, jfloat scaleRate,
         jfloat minScale, jfloat maxScale, jint history) {
     View* view = (View*) nativeView;
@@ -150,3 +153,17 @@ Java_com_google_android_filament_View_nSetDepthPrepass(JNIEnv *env,
     View* view = (View*) nativeView;
     view->setDepthPrepass(View::DepthPrepass(value));
 }
+
+extern "C" JNIEXPORT void JNICALL
+Java_com_google_android_filament_View_nSetPostProcessingEnabled(JNIEnv*,
+        jclass, jlong nativeView, jboolean enabled) {
+    View* view = (View*) nativeView;
+    view->setPostProcessingEnabled(enabled);
+}
+
+extern "C" JNIEXPORT jboolean JNICALL
+Java_com_google_android_filament_View_nIsPostProcessingEnabled(JNIEnv*,
+        jclass, jlong nativeView) {
+    View* view = (View*) nativeView;
+    return view->isPostProcessingEnabled();
+}

android/filament-android/src/main/java/com/google/android/filament/VertexBuffer.java

@@ -93,7 +93,7 @@ public class VertexBuffer {
 
         @NonNull
         public Builder attribute(@NonNull VertexAttribute attribute,
-                @IntRange(from = 1) int bufferIndex, @NonNull AttributeType attributeType,
+                @IntRange(from = 0) int bufferIndex, @NonNull AttributeType attributeType,
                 @IntRange(from = 0) int byteOffset, @IntRange(from = 0) int byteStride) {
             nBuilderAttribute(mNativeBuilder, attribute.ordinal(), bufferIndex,
                     attributeType.ordinal(), byteOffset, byteStride);
@@ -102,7 +102,7 @@ public class VertexBuffer {
 
         @NonNull
         public Builder attribute(@NonNull VertexAttribute attribute,
-                @IntRange(from = 1) int bufferIndex, @NonNull AttributeType attributeType) {
+                @IntRange(from = 0) int bufferIndex, @NonNull AttributeType attributeType) {
             return attribute(attribute, bufferIndex, attributeType, 0, 0 );
         }
 

android/filament-android/src/main/java/com/google/android/filament/View.java

@@ -28,7 +28,7 @@ public class View {
     private String mName;
     private Scene mScene;
     private Camera mCamera;
-    private Viewport mViewport;
+    private Viewport mViewport = new Viewport(0, 0, 0, 0);
     private DynamicResolutionOptions mDynamicResolution;
     private DepthPrepass mDepthPrepass = DepthPrepass.DEFAULT;
 
@@ -100,7 +100,7 @@ public class View {
                 mViewport.left, mViewport.bottom, mViewport.width, mViewport.height);
     }
 
-    @Nullable
+    @NonNull
     public Viewport getViewport() {
         return mViewport;
     }
@@ -179,6 +179,14 @@ public class View {
         nSetDepthPrepass(getNativeObject(), depthPrepass.value);
     }
 
+    public boolean isPostProcessingEnabled() {
+        return nIsPostProcessingEnabled(getNativeObject());
+    }
+
+    public void setPostProcessingEnabled(boolean enabled) {
+        nSetPostProcessingEnabled(getNativeObject(), enabled);
+    }
+
     public void setDynamicLightingOptions(float zLightNear, float zLightFar) {
         nSetDynamicLightingOptions(getNativeObject(), zLightNear, zLightFar);
     }
@@ -222,4 +230,6 @@ public class View {
             float minScale, float maxScale, int history);
     private static native void nSetDynamicLightingOptions(long nativeView, float zLightNear, float zLightFar);
     private static native void nSetDepthPrepass(long nativeView, int value);
+    private static native void nSetPostProcessingEnabled(long nativeView, boolean enabled);
+    private static native boolean nIsPostProcessingEnabled(long nativeView);
 }

android/filament-android/src/main/java/com/google/android/filament/android/UiHelper.java

@@ -135,6 +135,10 @@ public class UiHelper {
         mRenderCallback = renderCallback;
     }
 
+    public RendererCallback getRenderCallback() {
+        return mRenderCallback;
+    }
+
     /**
      * Free resources associated to the native window specified in attachTo().
      */

android/samples/hello-triangle/.gitignore

@@ -0,0 +1,11 @@
+*.iml
+.gradle
+/local.properties
+/.idea/workspace.xml
+/.idea/libraries
+/.idea/caches
+/.idea/gradle.xml
+.DS_Store
+/build
+/captures
+.externalNativeBuild

android/samples/hello-triangle/README.md

@@ -0,0 +1,21 @@
+# Hello Triangle
+
+This sample shows how to build a minimal Filament application for Android.
+
+## Android Studio
+
+Due to issues with composite builds in Android Studio 3.1, it is highly recommended to use
+Android Studio 3.2 to open this project.
+
+## Prerequisites
+
+Before you start, make sure to read [Filament's README](../../../README.md). You need to be able to
+compile Filament's native library and Filament's AAR for this project. The easiest way to proceed
+is to install all the required dependencies and to run the following command at the root of the
+source tree:
+
+```
+$ ./build.sh -p android release
+```
+
+This will build all the native components and the AAR required by this sample application.

android/samples/hello-triangle/app/.gitignore

@@ -0,0 +1 @@
+/build

android/samples/hello-triangle/app/build.gradle

@@ -0,0 +1,70 @@
+apply plugin: 'com.android.application'
+
+apply plugin: 'kotlin-android'
+
+apply plugin: 'kotlin-android-extensions'
+
+android {
+    compileSdkVersion 28
+    defaultConfig {
+        applicationId "com.google.android.filament.hellotriangle"
+        minSdkVersion 21
+        targetSdkVersion 28
+        versionCode 1
+        versionName "1.0"
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
+
+    // Filament comes with native code, the following declarations
+    // can be used to generate architecture specific APKs
+    flavorDimensions 'cpuArch'
+    productFlavors {
+        arm8 {
+            dimension 'cpuArch'
+            ndk {
+                abiFilters 'arm64-v8a'
+            }
+        }
+        arm7 {
+            dimension 'cpuArch'
+            ndk {
+                abiFilters 'armeabi-v7a'
+            }
+        }
+        x86_64 {
+            dimension 'cpuArch'
+            ndk {
+                abiFilters 'x86_64'
+            }
+        }
+        x86 {
+            dimension 'cpuArch'
+            ndk {
+                abiFilters 'x86'
+            }
+        }
+        universal {
+            dimension 'cpuArch'
+        }
+    }
+
+    // We use the .filamat extension for materials compiled with matc
+    // Telling aapt to not compress them allows to load them efficiently
+    aaptOptions {
+        noCompress 'filamat'
+    }
+}
+
+dependencies {
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
+
+    // Depend on Filament
+    implementation 'com.google.android.filament:filament-android'
+}

android/samples/hello-triangle/app/proguard-rules.pro

@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile

android/samples/hello-triangle/app/src/main/AndroidManifest.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.google.android.filament.hellotriangle">
+
+  <application
+      android:allowBackup="true"
+      android:icon="@mipmap/ic_launcher"
+      android:label="@string/app_name"
+      android:roundIcon="@mipmap/ic_launcher_round"
+      android:supportsRtl="true"
+      android:theme="@style/AppTheme">
+    <activity android:name=".MainActivity">
+      <intent-filter>
+        <action android:name="android.intent.action.MAIN"/>
+
+        <category android:name="android.intent.category.LAUNCHER"/>
+      </intent-filter>
+    </activity>
+  </application>
+
+</manifest>

android/samples/hello-triangle/app/src/main/java/com/google/android/filament/hellotriangle/MainActivity.kt

@@ -0,0 +1,342 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+package com.google.android.filament.hellotriangle
+
+import android.animation.ValueAnimator
+import android.app.Activity
+import android.opengl.Matrix
+import android.os.Bundle
+import android.view.Choreographer
+import android.view.Surface
+import android.view.SurfaceView
+import android.view.animation.LinearInterpolator
+
+import com.google.android.filament.*
+import com.google.android.filament.RenderableManager.*
+import com.google.android.filament.VertexBuffer.*
+import com.google.android.filament.android.UiHelper
+
+import java.io.IOException
+import java.nio.ByteBuffer
+import java.nio.ByteOrder
+import java.nio.channels.Channels
+
+import kotlin.math.PI
+import kotlin.math.cos
+import kotlin.math.sin
+
+class MainActivity : Activity() {
+    // Make sure to initialize Filament first
+    // This loads the JNI library needed by most API calls
+    companion object {
+        init {
+            Filament.init()
+        }
+    }
+
+    // The View we want to render into
+    private lateinit var surfaceView: SurfaceView
+    // UiHelper is provided by Filament to manage SurfaceView and SurfaceTexture
+    private lateinit var uiHelper: UiHelper
+    // Choreographer is used to schedule new frames
+    private lateinit var choreographer: Choreographer
+
+    // Engine creates and destroys Filament resources
+    // Each engine must be accessed from a single thread of your choosing
+    // Resources cannot be shared across engines
+    private lateinit var engine: Engine
+    // A renderer instance is tied to a single surface (SurfaceView, TextureView, etc.)
+    private lateinit var renderer: Renderer
+    // A scene holds all the renderable, lights, etc. to be drawn
+    private lateinit var scene: Scene
+    // A view defines a viewport, a scene and a camera for rendering
+    private lateinit var view: View
+    // Should be pretty obvious :)
+    private lateinit var camera: Camera
+
+    private lateinit var material: Material
+    private lateinit var vertexBuffer: VertexBuffer
+    private lateinit var indexBuffer: IndexBuffer
+
+    // Filament entity representing a renderable object
+    @Entity private var renderable = 0
+
+    // A swap chain is Filament's representation of a surface
+    private var swapChain: SwapChain? = null
+
+    // Performs the rendering and schedules new frames
+    private val frameScheduler = FrameCallback()
+
+    private val animator = ValueAnimator.ofFloat(0.0f, 360.0f)
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+
+        surfaceView = SurfaceView(this)
+        setContentView(surfaceView)
+
+        choreographer = Choreographer.getInstance()
+
+        setupSurfaceView()
+        setupFilament()
+        setupView()
+        setupScene()
+    }
+
+    private fun setupSurfaceView() {
+        uiHelper = UiHelper(UiHelper.ContextErrorPolicy.DONT_CHECK)
+        uiHelper.renderCallback = SurfaceCallback()
+
+        // NOTE: To choose a specific rendering resolution, add the following line:
+        // uiHelper.setDesiredSize(1280, 720)
+
+        uiHelper.attachTo(surfaceView)
+    }
+
+    private fun setupFilament() {
+        engine = Engine.create()
+        renderer = engine.createRenderer()
+        scene = engine.createScene()
+        view = engine.createView()
+        camera = engine.createCamera()
+    }
+
+    private fun setupView() {
+        // Clear the background to middle-grey
+        // Setting up a clear color is useful for debugging but usually
+        // unnecessary when using a skybox
+        view.setClearColor(0.035f, 0.035f, 0.035f, 1.0f)
+
+        // NOTE: Try to disable post-processing (tone-mapping, etc.) to see the difference
+        // view.isPostProcessingEnabled = false
+
+        // Tell the view which camera we want to use
+        view.camera = camera
+
+        // Tell the view which scene we want to render
+        view.scene = scene
+    }
+
+    private fun setupScene() {
+        loadMaterial()
+        createMesh()
+
+        // To create a renderable we first create a generic entity
+        renderable = EntityManager.get().create()
+
+        // We then create a renderable component on that entity
+        // A renderable is made of several primitives; in this case we declare only 1
+        RenderableManager.Builder(1)
+                // Overall bounding box of the renderable
+                .boundingBox(Box(0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.01f))
+                // Sets the mesh data of the first primitive
+                .geometry(0, PrimitiveType.TRIANGLES, vertexBuffer, indexBuffer, 0, 3)
+                // Sets the material of the first primitive
+                .material(0, material.defaultInstance)
+                .build(engine, renderable)
+
+        // Add the entity to the scene to render it
+        scene.addEntity(renderable)
+
+        // Animate the triangle
+        animator.interpolator = LinearInterpolator()
+        animator.duration = 4000
+        animator.repeatMode = ValueAnimator.RESTART
+        animator.repeatCount = ValueAnimator.INFINITE
+        animator.addUpdateListener(object : ValueAnimator.AnimatorUpdateListener {
+            val transformMatrix = FloatArray(16)
+            override fun onAnimationUpdate(a: ValueAnimator) {
+                Matrix.setRotateM(transformMatrix, 0, -(a.animatedValue as Float), 0.0f, 0.0f, 1.0f)
+                val tcm = engine.transformManager
+                tcm.setTransform(tcm.getInstance(renderable), transformMatrix)
+            }
+        })
+        animator.start()
+    }
+
+    private fun loadMaterial() {
+        readAsset("baked_color.filamat")?.let {
+            material = Material.Builder().payload(it, it.remaining()).build(engine)
+        }
+    }
+
+    private fun createMesh() {
+        val intSize = 4
+        val floatSize = 4
+        val shortSize = 2
+        // A vertex is a position + a color:
+        // 3 floats for XYZ position, 1 integer for color
+        val vertexSize = 3 * floatSize + intSize
+
+        // Define a vertex and a function to put a vertex in a ByteBuffer
+        data class Vertex(val x: Float, val y: Float, val z: Float, val color: Int)
+        fun ByteBuffer.put(v: Vertex): ByteBuffer {
+            putFloat(v.x)
+            putFloat(v.y)
+            putFloat(v.z)
+            putInt(v.color)
+            return this
+        }
+
+        // We are going to generate a single triangle
+        val vertexCount = 3
+        val a1 = PI * 2.0 / 3.0
+        val a2 = PI * 4.0 / 3.0
+
+        val vertexData = ByteBuffer.allocate(vertexCount * vertexSize)
+                // It is important to respect the native byte order
+                .order(ByteOrder.nativeOrder())
+                .put(Vertex(1.0f,              0.0f,              0.0f, 0xffff0000.toInt()))
+                .put(Vertex(cos(a1).toFloat(), sin(a1).toFloat(), 0.0f, 0xff00ff00.toInt()))
+                .put(Vertex(cos(a2).toFloat(), sin(a2).toFloat(), 0.0f, 0xff0000ff.toInt()))
+                // Make sure the cursor is pointing in the right place in the byte buffer
+                .flip()
+
+        // Declare the layout of our mesh
+        vertexBuffer = VertexBuffer.Builder()
+                .bufferCount(1)
+                .vertexCount(vertexCount)
+                // Because we interleave position and color data we must specify offset and stride
+                // We could use de-interleaved data by declaring two buffers and giving each
+                // attribute a different buffer index
+                .attribute(VertexAttribute.POSITION, 0, AttributeType.FLOAT3, 0,             vertexSize)
+                .attribute(VertexAttribute.COLOR,    0, AttributeType.UBYTE4, 3 * floatSize, vertexSize)
+                // We store colors as unsigned bytes but since we want values between 0 and 1
+                // in the material (shaders), we must mark the attribute as normalized
+                .normalized(VertexAttribute.COLOR)
+                .build(engine)
+
+        // Feed the vertex data to the mesh
+        // We only set 1 buffer because the data is interleaved
+        vertexBuffer.setBufferAt(engine, 0, vertexData)
+
+        // Create the indices
+        val indexData = ByteBuffer.allocate(vertexCount * shortSize)
+                .order(ByteOrder.nativeOrder())
+                .putShort(0)
+                .putShort(1)
+                .putShort(2)
+                .flip()
+
+        indexBuffer = IndexBuffer.Builder()
+                .indexCount(3)
+                .bufferType(IndexBuffer.Builder.IndexType.USHORT)
+                .build(engine)
+        indexBuffer.setBuffer(engine, indexData)
+    }
+
+    override fun onResume() {
+        super.onResume()
+        choreographer.postFrameCallback(frameScheduler)
+        animator.start()
+    }
+
+    override fun onPause() {
+        super.onPause()
+        choreographer.removeFrameCallback(frameScheduler)
+        animator.cancel()
+    }
+
+    override fun onDestroy() {
+        super.onDestroy()
+        // Always detach the surface before destroying the engine
+        uiHelper.detach()
+
+        // This ensures that all the commands we've sent to Filament have
+        // been processed before we attempt to destroy anything
+        Fence.waitAndDestroy(engine.createFence(Fence.Type.SOFT), Fence.Mode.FLUSH)
+
+        // Cleanup all resources
+        engine.renderableManager.destroy(renderable)
+        engine.destroyRenderer(renderer)
+        engine.destroyVertexBuffer(vertexBuffer)
+        engine.destroyIndexBuffer(indexBuffer)
+        engine.destroyMaterial(material)
+        engine.destroyView(view)
+        engine.destroyScene(scene)
+        engine.destroyCamera(camera)
+
+        // Destroying the engine will free up any resource you may have forgotten
+        // to destroy, but it's recommended to do the cleanup properly
+        engine.destroy()
+    }
+
+    inner class FrameCallback : Choreographer.FrameCallback {
+        override fun doFrame(frameTimeNanos: Long) {
+            // Schedule the next frame
+            choreographer.postFrameCallback(this)
+
+            // This check guarantees that we have a swap chain
+            if (uiHelper.isReadyToRender) {
+                // If beginFrame() returns false you should skip the frame
+                // This means you are sending frames too quickly to the GPU
+                if (renderer.beginFrame(swapChain!!)) {
+                    renderer.render(view)
+                    renderer.endFrame()
+                }
+            }
+        }
+    }
+
+    inner class SurfaceCallback : UiHelper.RendererCallback {
+        override fun onNativeWindowChanged(surface: Surface) {
+            swapChain?.let { engine.destroySwapChain(it) }
+            swapChain = engine.createSwapChain(surface)
+        }
+
+        override fun onDetachedFromSurface() {
+            swapChain?.let {
+                engine.destroySwapChain(it)
+                // Required to ensure we don't return before Filament is done executing the
+                // destroySwapChain command, otherwise Android might destroy the Surface
+                // too early
+                engine.flushAndWait()
+                swapChain = null
+            }
+        }
+
+        override fun onResized(width: Int, height: Int) {
+            val zoom = 1.5
+            val aspect = width.toDouble() / height.toDouble()
+            camera.setProjection(Camera.Projection.ORTHO,
+                    -aspect * zoom, aspect * zoom, -zoom, zoom, 0.0, 10.0)
+
+            view.viewport = Viewport(0, 0, width, height)
+        }
+    }
+
+    private fun readAsset(assetName: String): ByteBuffer? {
+        var dst: ByteBuffer? = null
+        try {
+            assets.openFd(assetName).use { fd ->
+                val input = fd.createInputStream()
+
+                dst = ByteBuffer.allocate(fd.length.toInt())
+
+                val src = Channels.newChannel(input)
+
+                src.read(dst)
+                src.close()
+                dst!!.rewind()
+            }
+        } catch (e: IOException) {
+            e.printStackTrace()
+        }
+
+        return dst
+    }
+}

android/samples/hello-triangle/app/src/main/res/drawable-v24/ic_launcher_foreground.xml

@@ -0,0 +1,34 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportHeight="108"
+    android:viewportWidth="108">
+  <path
+      android:fillType="evenOdd"
+      android:pathData="M32,64C32,64 38.39,52.99 44.13,50.95C51.37,48.37 70.14,49.57 70.14,49.57L108.26,87.69L108,109.01L75.97,107.97L32,64Z"
+      android:strokeColor="#00000000"
+      android:strokeWidth="1">
+    <aapt:attr name="android:fillColor">
+      <gradient
+          android:endX="78.5885"
+          android:endY="90.9159"
+          android:startX="48.7653"
+          android:startY="61.0927"
+          android:type="linear">
+        <item
+            android:color="#44000000"
+            android:offset="0.0"/>
+        <item
+            android:color="#00000000"
+            android:offset="1.0"/>
+      </gradient>
+    </aapt:attr>
+  </path>
+  <path
+      android:fillColor="#FFFFFF"
+      android:fillType="nonZero"
+      android:pathData="M66.94,46.02L66.94,46.02C72.44,50.07 76,56.61 76,64L32,64C32,56.61 35.56,50.11 40.98,46.06L36.18,41.19C35.45,40.45 35.45,39.3 36.18,38.56C36.91,37.81 38.05,37.81 38.78,38.56L44.25,44.05C47.18,42.57 50.48,41.71 54,41.71C57.48,41.71 60.78,42.57 63.68,44.05L69.11,38.56C69.84,37.81 70.98,37.81 71.71,38.56C72.44,39.3 72.44,40.45 71.71,41.19L66.94,46.02ZM62.94,56.92C64.08,56.92 65,56.01 65,54.88C65,53.76 64.08,52.85 62.94,52.85C61.8,52.85 60.88,53.76 60.88,54.88C60.88,56.01 61.8,56.92 62.94,56.92ZM45.06,56.92C46.2,56.92 47.13,56.01 47.13,54.88C47.13,53.76 46.2,52.85 45.06,52.85C43.92,52.85 43,53.76 43,54.88C43,56.01 43.92,56.92 45.06,56.92Z"
+      android:strokeColor="#00000000"
+      android:strokeWidth="1"/>
+</vector>

android/samples/hello-triangle/app/src/main/res/drawable/ic_launcher_background.xml

@@ -0,0 +1,171 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportHeight="108"
+    android:viewportWidth="108">
+  <path
+      android:fillColor="#26A69A"
+      android:pathData="M0,0h108v108h-108z"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M9,0L9,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M19,0L19,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M29,0L29,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M39,0L39,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M49,0L49,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M59,0L59,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M69,0L69,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M79,0L79,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M89,0L89,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M99,0L99,108"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,9L108,9"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,19L108,19"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,29L108,29"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,39L108,39"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,49L108,49"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,59L108,59"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,69L108,69"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,79L108,79"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,89L108,89"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M0,99L108,99"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M19,29L89,29"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M19,39L89,39"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M19,49L89,49"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M19,59L89,59"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M19,69L89,69"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M19,79L89,79"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M29,19L29,89"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M39,19L39,89"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M49,19L49,89"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M59,19L59,89"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M69,19L69,89"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+  <path
+      android:fillColor="#00000000"
+      android:pathData="M79,19L79,89"
+      android:strokeColor="#33FFFFFF"
+      android:strokeWidth="0.8"/>
+</vector>

android/samples/hello-triangle/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+  <background android:drawable="@drawable/ic_launcher_background"/>
+  <foreground android:drawable="@drawable/ic_launcher_foreground"/>
+</adaptive-icon>

android/samples/hello-triangle/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+  <background android:drawable="@drawable/ic_launcher_background"/>
+  <foreground android:drawable="@drawable/ic_launcher_foreground"/>
+</adaptive-icon>

android/samples/hello-triangle/app/src/main/res/values/colors.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+  <color name="colorPrimary">#3F51B5</color>
+  <color name="colorPrimaryDark">#303F9F</color>
+  <color name="colorAccent">#FF4081</color>
+</resources>

android/samples/hello-triangle/app/src/main/res/values/strings.xml

@@ -0,0 +1,3 @@
+<resources>
+  <string name="app_name">Hello Triangle</string>
+</resources>

android/samples/hello-triangle/app/src/main/res/values/styles.xml

@@ -0,0 +1,8 @@
+<resources>
+
+  <!-- Base application theme. -->
+  <style name="AppTheme" parent="android:Theme.Material.Light.DarkActionBar">
+    <!-- Customize your theme here. -->
+  </style>
+
+</resources>

android/samples/hello-triangle/app/src/materials/baked_color.mat

@@ -0,0 +1,36 @@
+// Simple unlit material that uses the colors associated with each vertex.
+//
+// This source material must be compiled to a binary material using the matc tool.
+// The command used to compile this material is:
+// matc -p mobile -a opengl -O -o app/src/main/assets/baked_color.filamat app/src/materials/baked_color.mat
+//
+// When Filament is updated all compiled materials should be regenerated. It is highly recommended
+// to integrate matc with your build system.
+// Please refer to the documentation for more information about matc and the materials system.
+
+material {
+    name : baked_color,
+
+    // Lists the required vertex attributes
+    // Here we only need a color (RGBA)
+    requires : [
+        color
+    ],
+
+    // This material disables all lighting
+    shadingModel : unlit,
+
+    // Both faces of the model's triangles are visible
+    culling : none,
+}
+
+fragment {
+    void material(inout MaterialInputs material) {
+        // You must always call the prepareMaterial() function
+        prepareMaterial(material);
+
+        // We set the material's color to the color interpolated from
+        // the model's vertices
+        material.baseColor = getColor();
+    }
+}

android/samples/hello-triangle/build.gradle

@@ -0,0 +1,27 @@
+// Top-level build file where you can add configuration options common to all sub-projects/modules.
+
+buildscript {
+    ext.kotlin_version = '1.2.60'
+    repositories {
+        google()
+        jcenter()
+    }
+    dependencies {
+        classpath 'com.android.tools.build:gradle:3.1.4'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+
+        // NOTE: Do not place your application dependencies here; they belong
+        // in the individual module build.gradle files
+    }
+}
+
+allprojects {
+    repositories {
+        google()
+        jcenter()
+    }
+}
+
+task clean(type: Delete) {
+    delete rootProject.buildDir
+}

android/samples/hello-triangle/gradle.properties

@@ -0,0 +1,13 @@
+# Project-wide Gradle settings.
+# IDE (e.g. Android Studio) users:
+# Gradle settings configured through the IDE *will override*
+# any settings specified in this file.
+# For more details on how to configure your build environment visit
+# http://www.gradle.org/docs/current/userguide/build_environment.html
+# Specifies the JVM arguments used for the daemon process.
+# The setting is particularly useful for tweaking memory settings.
+org.gradle.jvmargs=-Xmx1536m
+# When configured, Gradle will run in incubating parallel mode.
+# This option should only be used with decoupled projects. More details, visit
+# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
+# org.gradle.parallel=true

android/samples/hello-triangle/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,6 @@
+#Tue Aug 28 15:45:13 PDT 2018
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.6-all.zip

android/samples/hello-triangle/gradlew

@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+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
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+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="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$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
+
+# 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, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # 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`="\"$arg\""
+        fi
+        i=$((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 "$@")
+
+# 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"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"

android/samples/hello-triangle/gradlew.bat

@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+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
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+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
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+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!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

android/samples/hello-triangle/settings.gradle

@@ -0,0 +1,3 @@
+includeBuild '../../filament-android'
+
+include ':app'

filament/include/filament/View.h

@@ -395,6 +395,7 @@ public:
      */
     void setPostProcessingEnabled(bool enabled) noexcept;
 
+    bool isPostProcessingEnabled() const noexcept;
 
     // for debugging...
 

filament/src/View.cpp

@@ -832,6 +832,10 @@ void View::setPostProcessingEnabled(bool enabled) noexcept {
     upcast(this)->setPostProcessingEnabled(enabled);
 }
 
+bool View::isPostProcessingEnabled() const noexcept {
+    return upcast(this)->hasPostProcessPass();
+}
+
 void View::setDepthPrepass(View::DepthPrepass prepass) noexcept {
     upcast(this)->setDepthPrepass(prepass);
 }