gltfio: add Java bindings for instancing.

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();
+}