SurfaceTexture.java revision 5f8b6653e0b5b99097db7d8f41d5251f7b398704
16714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis/* 26714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * Copyright (C) 2010 The Android Open Source Project 36714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * 46714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * Licensed under the Apache License, Version 2.0 (the "License"); 56714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * you may not use this file except in compliance with the License. 66714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * You may obtain a copy of the License at 76714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * 86714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * http://www.apache.org/licenses/LICENSE-2.0 96714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * 106714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * Unless required by applicable law or agreed to in writing, software 116714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * distributed under the License is distributed on an "AS IS" BASIS, 126714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 136714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * See the License for the specific language governing permissions and 146714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * limitations under the License. 156714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis */ 166714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis 176714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennispackage android.graphics; 186714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis 19376590d668e22a918439877b55faf075427b13f3Jamie Gennisimport java.lang.ref.WeakReference; 20376590d668e22a918439877b55faf075427b13f3Jamie Gennisimport android.os.Handler; 21376590d668e22a918439877b55faf075427b13f3Jamie Gennisimport android.os.Looper; 22376590d668e22a918439877b55faf075427b13f3Jamie Gennisimport android.os.Message; 23376590d668e22a918439877b55faf075427b13f3Jamie Gennis 246714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis/** 256714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * Captures frames from an image stream as an OpenGL ES texture. 266714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * 2737cec0fc50760fe89614863eded14011f9412534Jamie Gennis * <p>The image stream may come from either camera preview. A SurfaceTexture may be used in place 2837cec0fc50760fe89614863eded14011f9412534Jamie Gennis * of a SurfaceHolder when specifying the output destination of a {@link android.hardware.Camera} 2937cec0fc50760fe89614863eded14011f9412534Jamie Gennis * object. Doing so will cause all the frames from the image stream to be sent to the 306714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * SurfaceTexture object rather than to the device's display. When {@link #updateTexImage} is 316714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * called, the contents of the texture object specified when the SurfaceTexture was created is 326714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * updated to contain the most recent image from the image stream. This may cause some frames of 336714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * the stream to be skipped. 346714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * 355f8b6653e0b5b99097db7d8f41d5251f7b398704Jamie Gennis * <p>When sampling from the texture one should first transform the texture coordinates using the 365f8b6653e0b5b99097db7d8f41d5251f7b398704Jamie Gennis * matrix queried via {@link #getTransformMatrix}. The transform matrix may change each time {@link 375f8b6653e0b5b99097db7d8f41d5251f7b398704Jamie Gennis * #updateTexImage} is called, so it should be re-queried each time the texture image is updated. 385f8b6653e0b5b99097db7d8f41d5251f7b398704Jamie Gennis * This matrix transforms traditional 2D OpenGL ES texture coordinate column vectors of the form (s, 395f8b6653e0b5b99097db7d8f41d5251f7b398704Jamie Gennis * t, 0, 1) where s and t are on the inclusive interval [0, 1] to the proper sampling location in 405f8b6653e0b5b99097db7d8f41d5251f7b398704Jamie Gennis * the streamed texture. This transform compensates for any properties of the image stream source 415f8b6653e0b5b99097db7d8f41d5251f7b398704Jamie Gennis * that cause it to appear different from a traditional OpenGL ES texture. For example, sampling 425f8b6653e0b5b99097db7d8f41d5251f7b398704Jamie Gennis * from the bottom left corner of the image can be accomplished by transforming the column vector 435f8b6653e0b5b99097db7d8f41d5251f7b398704Jamie Gennis * (0, 0, 0, 1) using the queried matrix, while sampling from the top right corner of the image can 445f8b6653e0b5b99097db7d8f41d5251f7b398704Jamie Gennis * be done by transforming (1, 1, 0, 1). 455f8b6653e0b5b99097db7d8f41d5251f7b398704Jamie Gennis * 466714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * <p>The texture object uses the GL_TEXTURE_EXTERNAL_OES texture target, which is defined by the 476714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * OES_EGL_image_external OpenGL ES extension. This limits how the texture may be used. 4837cec0fc50760fe89614863eded14011f9412534Jamie Gennis * 4937cec0fc50760fe89614863eded14011f9412534Jamie Gennis * <p>SurfaceTexture objects may be created on any thread. {@link #updateTexImage} may only be 5037cec0fc50760fe89614863eded14011f9412534Jamie Gennis * called on the thread with the OpenGL ES context that contains the texture object. The 5137cec0fc50760fe89614863eded14011f9412534Jamie Gennis * frame-available callback is called on an arbitrary thread, so unless special care is taken {@link 5237cec0fc50760fe89614863eded14011f9412534Jamie Gennis * #updateTexImage} should not be called directly from the callback. 536714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis */ 546714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennispublic class SurfaceTexture { 556714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis 56376590d668e22a918439877b55faf075427b13f3Jamie Gennis private EventHandler mEventHandler; 57376590d668e22a918439877b55faf075427b13f3Jamie Gennis private OnFrameAvailableListener mOnFrameAvailableListener; 58376590d668e22a918439877b55faf075427b13f3Jamie Gennis 596714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis @SuppressWarnings("unused") 606714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis private int mSurfaceTexture; 616714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis 626714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis /** 636714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * Callback interface for being notified that a new stream frame is available. 646714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis */ 656714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis public interface OnFrameAvailableListener { 666714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis void onFrameAvailable(SurfaceTexture surfaceTexture); 676714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis } 686714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis 696714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis /** 706714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * Exception thrown when a surface couldn't be created or resized 716714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis */ 726714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis public static class OutOfResourcesException extends Exception { 736714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis public OutOfResourcesException() { 746714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis } 756714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis public OutOfResourcesException(String name) { 766714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis super(name); 776714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis } 786714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis } 796714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis 806714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis /** 816714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * Construct a new SurfaceTexture to stream images to a given OpenGL texture. 826714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * 836714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * @param texName the OpenGL texture object name (e.g. generated via glGenTextures) 846714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis */ 856714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis public SurfaceTexture(int texName) { 86376590d668e22a918439877b55faf075427b13f3Jamie Gennis Looper looper; 87376590d668e22a918439877b55faf075427b13f3Jamie Gennis if ((looper = Looper.myLooper()) != null) { 88376590d668e22a918439877b55faf075427b13f3Jamie Gennis mEventHandler = new EventHandler(looper); 89376590d668e22a918439877b55faf075427b13f3Jamie Gennis } else if ((looper = Looper.getMainLooper()) != null) { 90376590d668e22a918439877b55faf075427b13f3Jamie Gennis mEventHandler = new EventHandler(looper); 91376590d668e22a918439877b55faf075427b13f3Jamie Gennis } else { 92376590d668e22a918439877b55faf075427b13f3Jamie Gennis mEventHandler = null; 93376590d668e22a918439877b55faf075427b13f3Jamie Gennis } 94376590d668e22a918439877b55faf075427b13f3Jamie Gennis nativeInit(texName, new WeakReference<SurfaceTexture>(this)); 956714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis } 966714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis 976714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis /** 986714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * Register a callback to be invoked when a new image frame becomes available to the 996714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * SurfaceTexture. Note that this callback may be called on an arbitrary thread, so it is not 1006714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * safe to call {@link #updateTexImage} without first binding the OpenGL ES context to the 1016714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * thread invoking the callback. 1026714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis */ 1036714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis public void setOnFrameAvailableListener(OnFrameAvailableListener l) { 104376590d668e22a918439877b55faf075427b13f3Jamie Gennis mOnFrameAvailableListener = l; 1056714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis } 1066714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis 1076714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis /** 1086714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * Update the texture image to the most recent frame from the image stream. This may only be 1096714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * called while the OpenGL ES context that owns the texture is bound to the thread. It will 1106714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * implicitly bind its texture to the GL_TEXTURE_EXTERNAL_OES texture target. 1116714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis */ 112376590d668e22a918439877b55faf075427b13f3Jamie Gennis public void updateTexImage() { 113376590d668e22a918439877b55faf075427b13f3Jamie Gennis nativeUpdateTexImage(); 114376590d668e22a918439877b55faf075427b13f3Jamie Gennis } 115b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis 116b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis /** 117b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis * Retrieve the 4x4 texture coordinate transform matrix associated with the texture image set by 118b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis * the most recent call to updateTexImage. 119b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis * 120b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis * This transform matrix maps 2D homogeneous texture coordinates of the form (s, t, 0, 1) with s 121b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis * and t in the inclusive range [0, 1] to the texture coordinate that should be used to sample 122b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis * that location from the texture. Sampling the texture outside of the range of this transform 123b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis * is undefined. 124b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis * 125b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis * The matrix is stored in column-major order so that it may be passed directly to OpenGL ES via 126b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis * the glLoadMatrixf or glUniformMatrix4fv functions. 127b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis * 128b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis * @param mtx the array into which the 4x4 matrix will be stored. The array must have exactly 129b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis * 16 elements. 130b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis */ 131b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis public void getTransformMatrix(float[] mtx) { 132b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis if (mtx.length != 16) { 133b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis throw new IllegalArgumentException(); 134b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis } 135376590d668e22a918439877b55faf075427b13f3Jamie Gennis nativeGetTransformMatrix(mtx); 136b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis } 137b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis 138376590d668e22a918439877b55faf075427b13f3Jamie Gennis protected void finalize() throws Throwable { 139376590d668e22a918439877b55faf075427b13f3Jamie Gennis try { 140376590d668e22a918439877b55faf075427b13f3Jamie Gennis nativeFinalize(); 141376590d668e22a918439877b55faf075427b13f3Jamie Gennis } finally { 142376590d668e22a918439877b55faf075427b13f3Jamie Gennis super.finalize(); 143376590d668e22a918439877b55faf075427b13f3Jamie Gennis } 144376590d668e22a918439877b55faf075427b13f3Jamie Gennis } 145376590d668e22a918439877b55faf075427b13f3Jamie Gennis 146376590d668e22a918439877b55faf075427b13f3Jamie Gennis private class EventHandler extends Handler { 147376590d668e22a918439877b55faf075427b13f3Jamie Gennis public EventHandler(Looper looper) { 148376590d668e22a918439877b55faf075427b13f3Jamie Gennis super(looper); 149376590d668e22a918439877b55faf075427b13f3Jamie Gennis } 150376590d668e22a918439877b55faf075427b13f3Jamie Gennis 151376590d668e22a918439877b55faf075427b13f3Jamie Gennis @Override 152376590d668e22a918439877b55faf075427b13f3Jamie Gennis public void handleMessage(Message msg) { 153376590d668e22a918439877b55faf075427b13f3Jamie Gennis if (mOnFrameAvailableListener != null) { 154376590d668e22a918439877b55faf075427b13f3Jamie Gennis mOnFrameAvailableListener.onFrameAvailable(SurfaceTexture.this); 155376590d668e22a918439877b55faf075427b13f3Jamie Gennis } 156376590d668e22a918439877b55faf075427b13f3Jamie Gennis return; 157376590d668e22a918439877b55faf075427b13f3Jamie Gennis } 158376590d668e22a918439877b55faf075427b13f3Jamie Gennis } 159376590d668e22a918439877b55faf075427b13f3Jamie Gennis 160376590d668e22a918439877b55faf075427b13f3Jamie Gennis private static void postEventFromNative(Object selfRef) { 161376590d668e22a918439877b55faf075427b13f3Jamie Gennis WeakReference weakSelf = (WeakReference)selfRef; 162376590d668e22a918439877b55faf075427b13f3Jamie Gennis SurfaceTexture st = (SurfaceTexture)weakSelf.get(); 163376590d668e22a918439877b55faf075427b13f3Jamie Gennis if (st == null) { 164376590d668e22a918439877b55faf075427b13f3Jamie Gennis return; 165376590d668e22a918439877b55faf075427b13f3Jamie Gennis } 166376590d668e22a918439877b55faf075427b13f3Jamie Gennis 167376590d668e22a918439877b55faf075427b13f3Jamie Gennis if (st.mEventHandler != null) { 168376590d668e22a918439877b55faf075427b13f3Jamie Gennis Message m = st.mEventHandler.obtainMessage(); 169376590d668e22a918439877b55faf075427b13f3Jamie Gennis st.mEventHandler.sendMessage(m); 170376590d668e22a918439877b55faf075427b13f3Jamie Gennis } 171376590d668e22a918439877b55faf075427b13f3Jamie Gennis } 172b0ba48c95ea8768a051100c5adb4c906caa1e080Jamie Gennis 173376590d668e22a918439877b55faf075427b13f3Jamie Gennis private native void nativeInit(int texName, Object weakSelf); 174376590d668e22a918439877b55faf075427b13f3Jamie Gennis private native void nativeFinalize(); 175376590d668e22a918439877b55faf075427b13f3Jamie Gennis private native void nativeGetTransformMatrix(float[] mtx); 176376590d668e22a918439877b55faf075427b13f3Jamie Gennis private native void nativeUpdateTexImage(); 1776714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis 1786714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis /* 1796714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * We use a class initializer to allow the native code to cache some 1806714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis * field offsets. 1816714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis */ 1826714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis private static native void nativeClassInit(); 1836714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis static { nativeClassInit(); } 1846714efc5e0c52953b65e774de0003e22377e7d39Jamie Gennis} 185