Convert KtxLoader to Kotlin and remove usage of reflection.

Fixes #1510

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

@@ -86,8 +86,7 @@ import com.google.android.filament.proguard.UsedByReflection;
 public class IndirectLight {
     long mNativeObject;
 
-    @UsedByReflection("KtxLoader.java")
-    IndirectLight(long indirectLight) {
+    public IndirectLight(long indirectLight) {
         mNativeObject = indirectLight;
     }
 

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

@@ -49,8 +49,7 @@ import com.google.android.filament.proguard.UsedByReflection;
 public class Skybox {
     private long mNativeObject;
 
-    @UsedByReflection("KtxLoader.java")
-    Skybox(long nativeSkybox) {
+    public Skybox(long nativeSkybox) {
         mNativeObject = nativeSkybox;
     }
 

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

@@ -73,8 +73,7 @@ import static com.google.android.filament.Texture.Type.COMPRESSED;
 public class Texture {
     private long mNativeObject;
 
-    @UsedByReflection("KtxLoader.java")
-    Texture(long nativeTexture) {
+    public Texture(long nativeTexture) {
         mNativeObject = nativeTexture;
     }
 

android/filament-utils-android/src/main/java/com/google/android/filament/utils/KtxLoader.java

@@ -1,120 +0,0 @@
-/*
- * 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.utils;
-
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-
-import com.google.android.filament.Engine;
-import com.google.android.filament.IndirectLight;
-import com.google.android.filament.Skybox;
-import com.google.android.filament.Texture;
-
-import java.lang.reflect.Constructor;
-import java.nio.Buffer;
-
-/**
- * Utilities for consuming KTX files and producing Filament textures, IBLs, and sky boxes.
- *
- * <p>KTX is a simple container format that makes it easy to bundle miplevels and cubemap faces
- * into a single file.</p>
- */
-public class KtxLoader {
-    private static Constructor<Texture> sTextureConstructor;
-    private static Constructor<IndirectLight> sIndirectLightConstructor;
-    private static Constructor<Skybox> sSkyboxConstructor;
-
-    static {
-        try {
-            sTextureConstructor = Texture.class.getDeclaredConstructor(long.class);
-            sTextureConstructor.setAccessible(true);
-
-            sIndirectLightConstructor = IndirectLight.class.getDeclaredConstructor(long.class);
-            sIndirectLightConstructor.setAccessible(true);
-
-            sSkyboxConstructor = Skybox.class.getDeclaredConstructor(long.class);
-            sSkyboxConstructor.setAccessible(true);
-        } catch (NoSuchMethodException e) {
-            // Cannot happen
-        }
-    }
-
-    public static class Options {
-        public boolean srgb;
-    }
-
-    /**
-     * Consumes the content of a KTX file and produces a {@link Texture} object.
-     *
-     * @param engine Gets passed to the builder.
-     * @param buffer The content of the KTX File.
-     * @param options Loader options.
-     * @return The resulting Filament texture, or null on failure.
-     */
-    @Nullable
-    public static Texture createTexture(@NonNull Engine engine, @NonNull Buffer buffer, @NonNull Options options) {
-        try {
-            long nativeEngine = engine.getNativeObject();
-            long nativeTexture = nCreateTexture(nativeEngine, buffer, buffer.remaining(), options.srgb);
-            return sTextureConstructor.newInstance(nativeTexture);
-        } catch (Exception e) {
-            return null;
-        }
-    }
-
-    /**
-     * Consumes the content of a KTX file and produces an {@link IndirectLight} object.
-     *
-     * @param engine Gets passed to the builder.
-     * @param buffer The content of the KTX File.
-     * @param options Loader options.
-     * @return The resulting Filament texture, or null on failure.
-     */
-    @Nullable
-    public static IndirectLight createIndirectLight(@NonNull Engine engine, @NonNull Buffer buffer, @NonNull Options options) {
-        try {
-            long nativeEngine = engine.getNativeObject();
-            long nativeIndirectLight = nCreateIndirectLight(nativeEngine, buffer, buffer.remaining(), options.srgb);
-            return sIndirectLightConstructor.newInstance(nativeIndirectLight);
-        } catch (Exception e) {
-            return null;
-        }
-    }
-
-    /**
-     * Consumes the content of a KTX file and produces a {@link Skybox} object.
-     *
-     * @param engine Gets passed to the builder.
-     * @param buffer The content of the KTX File.
-     * @param options Loader options.
-     * @return The resulting Filament texture, or null on failure.
-     */
-    @Nullable
-    public static Skybox createSkybox(@NonNull Engine engine, @NonNull Buffer buffer, @NonNull Options options) {
-        try {
-            long nativeEngine = engine.getNativeObject();
-            long nativeSkybox = nCreateSkybox(nativeEngine, buffer, buffer.remaining(), options.srgb);
-            return sSkyboxConstructor.newInstance(nativeSkybox);
-        } catch (Exception e) {
-            return null;
-        }
-    }
-
-    private static native long nCreateTexture(long nativeEngine, Buffer buffer, int remaining, boolean srgb);
-    private static native long nCreateIndirectLight(long nativeEngine, Buffer buffer, int remaining, boolean srgb);
-    private static native long nCreateSkybox(long nativeEngine, Buffer buffer, int remaining, boolean srgb);
-}

android/filament-utils-android/src/main/java/com/google/android/filament/utils/KtxLoader.kt

@@ -0,0 +1,82 @@
+/*
+ * 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.utils
+
+import com.google.android.filament.Engine
+import com.google.android.filament.IndirectLight
+import com.google.android.filament.Skybox
+import com.google.android.filament.Texture
+
+import java.nio.Buffer
+
+/**
+ * Utilities for consuming KTX files and producing Filament textures, IBLs, and sky boxes.
+ *
+ * KTX is a simple container format that makes it easy to bundle miplevels and cubemap faces
+ * into a single file.
+ */
+object KtxLoader {
+    class Options {
+        var srgb = false
+    }
+
+    /**
+     * Consumes the content of a KTX file and produces a [Texture] object.
+     *
+     * @param engine Gets passed to the builder.
+     * @param buffer The content of the KTX File.
+     * @param options Loader options.
+     * @return The resulting Filament texture, or null on failure.
+     */
+    fun createTexture(engine: Engine, buffer: Buffer, options: Options): Texture {
+        val nativeEngine = engine.nativeObject
+        val nativeTexture = nCreateTexture(nativeEngine, buffer, buffer.remaining(), options.srgb)
+        return Texture(nativeTexture)
+    }
+
+    /**
+     * Consumes the content of a KTX file and produces an [IndirectLight] object.
+     *
+     * @param engine Gets passed to the builder.
+     * @param buffer The content of the KTX File.
+     * @param options Loader options.
+     * @return The resulting Filament texture, or null on failure.
+     */
+    fun createIndirectLight(engine: Engine, buffer: Buffer, options: Options): IndirectLight {
+        val nativeEngine = engine.nativeObject
+        val nativeIndirectLight = nCreateIndirectLight(nativeEngine, buffer, buffer.remaining(), options.srgb)
+        return IndirectLight(nativeIndirectLight)
+    }
+
+    /**
+     * Consumes the content of a KTX file and produces a [Skybox] object.
+     *
+     * @param engine Gets passed to the builder.
+     * @param buffer The content of the KTX File.
+     * @param options Loader options.
+     * @return The resulting Filament texture, or null on failure.
+     */
+    fun createSkybox(engine: Engine, buffer: Buffer, options: Options): Skybox {
+        val nativeEngine = engine.nativeObject
+        val nativeSkybox = nCreateSkybox(nativeEngine, buffer, buffer.remaining(), options.srgb)
+        return Skybox(nativeSkybox)
+    }
+
+    private external fun nCreateTexture(nativeEngine: Long, buffer: Buffer, remaining: Int, srgb: Boolean): Long
+    private external fun nCreateIndirectLight(nativeEngine: Long, buffer: Buffer, remaining: Int, srgb: Boolean): Long
+    private external fun nCreateSkybox(nativeEngine: Long, buffer: Buffer, remaining: Int, srgb: Boolean): Long
+}