gltfio: add Java bindings for instancing.

android/gltfio-android/CMakeLists.txt

@@ -31,6 +31,7 @@ set(GLTFIO_SRCS
         ${GLTFIO_DIR}/include/gltfio/ResourceLoader.h
         ${GLTFIO_DIR}/include/gltfio/SimpleViewer.h
         ${GLTFIO_DIR}/include/gltfio/FilamentAsset.h
+        ${GLTFIO_DIR}/include/gltfio/FilamentInstance.h
 
         ${GLTFIO_DIR}/src/Animator.cpp
         ${GLTFIO_DIR}/src/AssetLoader.cpp
@@ -40,6 +41,8 @@ set(GLTFIO_SRCS
         ${GLTFIO_DIR}/src/DependencyGraph.h
         ${GLTFIO_DIR}/src/FFilamentAsset.h
         ${GLTFIO_DIR}/src/FilamentAsset.cpp
+        ${GLTFIO_DIR}/src/FFilamentInstance.h
+        ${GLTFIO_DIR}/src/FilamentInstance.cpp
         ${GLTFIO_DIR}/src/GltfEnums.h
         ${GLTFIO_DIR}/src/MaterialProvider.cpp
         ${GLTFIO_DIR}/src/ResourceLoader.cpp
@@ -53,6 +56,7 @@ set(GLTFIO_SRCS
         src/main/cpp/Animator.cpp
         src/main/cpp/AssetLoader.cpp
         src/main/cpp/FilamentAsset.cpp
+        src/main/cpp/FilamentInstance.cpp
         src/main/cpp/MaterialProvider.cpp
         src/main/cpp/ResourceLoader.cpp
 

android/gltfio-android/src/main/cpp/AssetLoader.cpp

@@ -67,6 +67,27 @@ Java_com_google_android_filament_gltfio_AssetLoader_nCreateAssetFromJson(JNIEnv*
             buffer.getSize());
 }
 
+extern "C" JNIEXPORT jlong JNICALL
+Java_com_google_android_filament_gltfio_AssetLoader_nCreateInstancedAsset(JNIEnv* env, jclass,
+        jlong nativeLoader, jobject javaBuffer, jint remaining, jlongArray instances) {
+    AssetLoader* loader = (AssetLoader*) nativeLoader;
+    AutoBuffer buffer(env, javaBuffer, remaining);
+    jsize numInstances = env->GetArrayLength(instances);
+    using Handle = FilamentInstance*;
+    Handle* ptrInstances = new Handle[numInstances];
+    jlong asset = (jlong) loader->createInstancedAsset((const uint8_t *) buffer.getData(),
+            buffer.getSize(), ptrInstances, numInstances);
+    if (asset) {
+        jlong* longInstances = env->GetLongArrayElements(instances, nullptr);
+        for (jsize i = 0; i < numInstances; i++) {
+            longInstances[i] = (jlong) ptrInstances[i];
+        }
+        env->ReleaseLongArrayElements(instances, longInstances, 0);
+    }
+    delete[] ptrInstances;
+    return asset;
+}
+
 extern "C" JNIEXPORT void JNICALL
 Java_com_google_android_filament_gltfio_AssetLoader_nEnableDiagnostics(JNIEnv*, jclass,
         jlong nativeLoader, jboolean enable) {

android/gltfio-android/src/main/cpp/FilamentInstance.cpp

@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2020 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 <jni.h>
+
+#include <gltfio/FilamentInstance.h>
+
+#include <algorithm>
+
+using namespace gltfio;
+using namespace utils;
+
+extern "C" JNIEXPORT jint JNICALL
+Java_com_google_android_filament_gltfio_FilamentInstance_nGetRoot(JNIEnv*, jclass,
+        jlong nativeInstance) {
+    FilamentInstance* instance = (FilamentInstance*) nativeInstance;
+    return instance->getRoot().getId();
+}
+
+extern "C" JNIEXPORT jint JNICALL
+Java_com_google_android_filament_gltfio_FilamentInstance_nGetEntityCount(JNIEnv*, jclass,
+        jlong nativeInstance) {
+    FilamentInstance* instance = (FilamentInstance*) nativeInstance;
+    return instance->getEntityCount();
+}
+
+extern "C" JNIEXPORT void JNICALL
+Java_com_google_android_filament_gltfio_FilamentInstance_nGetEntities(JNIEnv* env, jclass,
+        jlong nativeInstance, jintArray result) {
+    FilamentInstance* instance = (FilamentInstance*) nativeInstance;
+    jsize available = env->GetArrayLength(result);
+    Entity* entities = (Entity*) env->GetIntArrayElements(result, nullptr);
+    std::copy_n(instance->getEntities(),
+            std::min(available, (jsize) instance->getEntityCount()), entities);
+    env->ReleaseIntArrayElements(result, (jint*) entities, 0);
+}
+
+extern "C" JNIEXPORT jlong JNICALL
+Java_com_google_android_filament_gltfio_FilamentInstance_nGetAnimator(JNIEnv* , jclass,
+        jlong nativeInstance) {
+    FilamentInstance* instance = (FilamentInstance*) nativeInstance;
+    return (jlong) instance->getAnimator();
+}

android/gltfio-android/src/main/java/com/google/android/filament/gltfio/AssetLoader.java

@@ -128,9 +128,34 @@ public class AssetLoader {
         return nativeAsset != 0 ? new FilamentAsset(mEngine, nativeAsset) : null;
     }
 
+    /**
+     * Consumes the contents of a glTF 2.0 file and produces a master asset with one or more
+     * instances.
+     *
+     * The given instance array must be sized to the desired number of instances. If successful,
+     * this method will populate the array with slave instances whose resources are shared with
+     * the master asset.
+     */
+    @Nullable
+    @SuppressWarnings("unused")
+    public FilamentAsset createInstancedAsset(@NonNull Buffer buffer,
+            @NonNull FilamentInstance[] instances) {
+        long[] nativeInstances = new long[instances.length];
+        long nativeAsset = nCreateInstancedAsset(mNativeObject, buffer, buffer.remaining(),
+                nativeInstances);
+        if (nativeAsset == 0) {
+            return null;
+        }
+        for (int i = 0; i < nativeInstances.length; i++) {
+            instances[i] = new FilamentInstance(nativeInstances[i]);
+        }
+        return new FilamentAsset(mEngine, nativeAsset);
+    }
+
     /**
      * Allows clients to enable diagnostic shading on newly-loaded assets.
      */
+    @SuppressWarnings("unused")
     public void enableDiagnostics(boolean enable) {
         nEnableDiagnostics(mNativeObject, enable);
     }
@@ -148,6 +173,8 @@ public class AssetLoader {
     private static native void nDestroyAssetLoader(long nativeLoader);
     private static native long nCreateAssetFromBinary(long nativeLoader, Buffer buffer, int remaining);
     private static native long nCreateAssetFromJson(long nativeLoader, Buffer buffer, int remaining);
+    private static native long nCreateInstancedAsset(long nativeLoader, Buffer buffer, int remaining,
+            long[] nativeInstances);
     private static native void nEnableDiagnostics(long nativeLoader, boolean enable);
     private static native void nDestroyAsset(long nativeLoader, long nativeAsset);
 }

android/gltfio-android/src/main/java/com/google/android/filament/gltfio/FilamentInstance.java

@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2020 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.gltfio;
+
+import androidx.annotation.NonNull;
+
+import com.google.android.filament.Entity;
+
+/**
+ * Provides access to a hierarchy of entities that have been instanced from a glTF asset.
+ *
+ * @see FilamentAsset
+ * @see Animator
+ * @see AssetLoader
+ */
+public class FilamentInstance {
+    private long mNativeObject;
+    private Animator mAnimator;
+
+    FilamentInstance(long nativeObject) {
+        mNativeObject = nativeObject;
+        mAnimator = null;
+    }
+
+    @SuppressWarnings("unused")
+    long getNativeObject() {
+        return mNativeObject;
+    }
+
+    @SuppressWarnings("unused")
+    void clearNativeObject() {
+        mNativeObject = 0;
+    }
+
+    /**
+     * Gets the transform root for the asset, which has no matching glTF node.
+     */
+    @SuppressWarnings("unused")
+    public @Entity int getRoot() {
+        return nGetRoot(mNativeObject);
+    }
+
+    /**
+     * Gets the list of entities for this instance, one for each glTF node.
+     *
+     * <p>All of these have a transform component. Some of the returned entities may also have a
+     * renderable component.</p>
+     */
+    public @NonNull @Entity int[] getEntities() {
+        int[] result = new int[nGetEntityCount(mNativeObject)];
+        nGetEntities(mNativeObject, result);
+        return result;
+    }
+
+    /**
+     * Creates or retrieves the <code>Animator</code> for this instance.
+     *
+     * <p>When calling this for the first time, this must be called after
+     * {@link ResourceLoader#loadResources}.</p>
+     */
+    public @NonNull Animator getAnimator() {
+        if (mAnimator != null) {
+            return mAnimator;
+        }
+        mAnimator = new Animator(nGetAnimator(mNativeObject));
+        return mAnimator;
+    }
+
+    private static native int nGetRoot(long nativeAsset);
+    private static native int nGetEntityCount(long nativeAsset);
+    private static native void nGetEntities(long nativeAsset, int[] result);
+    private static native long nGetAnimator(long nativeAsset);
+}