android - 如何在 Android Ice Cream Sandwich 中用 TextureView 替换 GLSurfaceView？

Question

纹理 View documentation声明它可用于渲染 OpenGL 内容。

在 blog post在宣布 TextureView 时，它声明:

A TextureView can just as easily be used to embed an OpenGL scene in your application. As of Android 4.0, eglCreateWindowSurface() can be used to render into a SurfaceTexture object.

这似乎意味着要使用 TextureView 而不是 GLSurfaceView，必须自己完成所有 EGL 设置并管理 EGLContext 和线程(因为 GLSurfaceView 维护一个 GLThread)。 Android 4.0 SDK 中似乎没有任何示例代码来演示“TextureView 可以很容易地用于嵌入 OpenGL 场景”。 TextureView 似乎更干净地插入到相机预览 (setPreviewTexture) 和 MediaPlayer (setSurface)。

是否可以通过使用 GLSurfaceView.setEGLWindowSurfaceFactory 将 GLSurfaceView 与 TextureView 结合使用，使其渲染到 TextureView 的 SurfaceTexture？

同样，如果有一些示例代码就好了。

Answer 1

版主删除了此答案，因此将其添加回来以供后代使用:

查看来自 android-dev google 组的 Romain Guy 的回答(2011 年 11 月 23 日):

http://groups.google.com/group/android-developers/browse_thread/thread/539457146a401cf1 (镜像:http://grokbase.com/t/gg/android-developers/11bqmgb7sw/how-to-replace-glsurfaceview-with-textureview-in-android-ice-cream-sandwich)

GLSurfaceView handles GL setup for you, which TextureView will not do. A TextureView can be used as the native window when you create an EGL surface. Here is an example (the interesting part is the call to eglCreateWindowSurface()):

 @Override
 public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
     mRenderThread = new RenderThread(getResources(), surface);
     mRenderThread.start();
 }

 private static class RenderThread extends Thread {
     private static final String LOG_TAG = "GLTextureView";

     static final int EGL_CONTEXT_CLIENT_VERSION = 0x3098;
     static final int EGL_OPENGL_ES2_BIT = 4;

     private volatile boolean mFinished;

     private final Resources mResources;
     private final SurfaceTexture mSurface;

     private EGL10 mEgl;
     private EGLDisplay mEglDisplay;
     private EGLConfig mEglConfig;
     private EGLContext mEglContext;
     private EGLSurface mEglSurface;
     private GL mGL;

     RenderThread(Resources resources, SurfaceTexture surface) {
         mResources = resources;
         mSurface = surface;
     }

     private static final String sSimpleVS =
             "attribute vec4 position;\n" +
             "attribute vec2 texCoords;\n" +
             "varying vec2 outTexCoords;\n" +
             "\nvoid main(void) {\n" +
             " outTexCoords = texCoords;\n" +
             " gl_Position = position;\n" +
             "}\n\n";
     private static final String sSimpleFS =
             "precision mediump float;\n\n" +
             "varying vec2 outTexCoords;\n" +
             "uniform sampler2D texture;\n" +
             "\nvoid main(void) {\n" +
             " gl_FragColor = texture2D(texture, outTexCoords);\n" +
             "}\n\n";

     private static final int FLOAT_SIZE_BYTES = 4;
     private static final int TRIANGLE_VERTICES_DATA_STRIDE_BYTES = 5 * FLOAT_SIZE_BYTES;
     private static final int TRIANGLE_VERTICES_DATA_POS_OFFSET = 0;
     private static final int TRIANGLE_VERTICES_DATA_UV_OFFSET = 3;
     private final float[] mTriangleVerticesData = {
             // X, Y, Z, U, V
             -1.0f, -1.0f, 0.0f, 0.0f, 0.0f,
              1.0f, -1.0f, 0.0f, 1.0f, 0.0f,
             -1.0f, 1.0f, 0.0f, 0.0f, 1.0f,
              1.0f, 1.0f, 0.0f, 1.0f, 1.0f,
     };

     @Override
     public void run() {
         initGL();

         FloatBuffer triangleVertices = ByteBuffer.allocateDirect(mTriangleVerticesData.length * FLOAT_SIZE_BYTES).order(ByteOrder.nativeOrder()).asFloatBuffer();
         triangleVertices.put(mTriangleVerticesData).position(0);

         int texture = loadTexture(R.drawable.large_photo);
         int program = buildProgram(sSimpleVS, sSimpleFS);

         int attribPosition = glGetAttribLocation(program, "position");
         checkGlError();

         int attribTexCoords = glGetAttribLocation(program, "texCoords");
         checkGlError();

         int uniformTexture = glGetUniformLocation(program, "texture");
         checkGlError();

         glBindTexture(GL_TEXTURE_2D, texture);
         checkGlError();

         glUseProgram(program);
         checkGlError();

         glEnableVertexAttribArray(attribPosition);
         checkGlError();

         glEnableVertexAttribArray(attribTexCoords);
         checkGlError();

         glUniform1i(uniformTexture, texture);
         checkGlError();

         while (!mFinished) {
             checkCurrent();

             glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
             checkGlError();

             glClear(GL_COLOR_BUFFER_BIT);
             checkGlError();

             // drawQuad

             triangleVertices.position(TRIANGLE_VERTICES_DATA_POS_OFFSET);
             glVertexAttribPointer(attribPosition, 3, GL_FLOAT, false,
                     TRIANGLE_VERTICES_DATA_STRIDE_BYTES, triangleVertices);

             triangleVertices.position(TRIANGLE_VERTICES_DATA_UV_OFFSET);
             glVertexAttribPointer(attribTexCoords, 3, GL_FLOAT, false,
                     TRIANGLE_VERTICES_DATA_STRIDE_BYTES, triangleVertices);

             glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

             if (!mEgl.eglSwapBuffers(mEglDisplay, mEglSurface)) {
                 throw new RuntimeException("Cannot swap buffers");
             }
             checkEglError();

             try {
                 Thread.sleep(2000);
             } catch (InterruptedException e) {
                 // Ignore
             }
         }

         finishGL();
     }

     private int loadTexture(int resource) {
         int[] textures = new int[1];

         glActiveTexture(GL_TEXTURE0);
         glGenTextures(1, textures, 0);
         checkGlError();

         int texture = textures[0];
         glBindTexture(GL_TEXTURE_2D, texture);
         checkGlError();

         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

         Bitmap bitmap = BitmapFactory.decodeResource(mResources, resource);

         GLUtils.texImage2D(GL_TEXTURE_2D, 0, GL_RGBA, bitmap, GL_UNSIGNED_BYTE, 0);
         checkGlError();

         bitmap.recycle();

         return texture;
     }

     private int buildProgram(String vertex, String fragment) {
         int vertexShader = buildShader(vertex, GL_VERTEX_SHADER);
         if (vertexShader == 0) return 0;

         int fragmentShader = buildShader(fragment, GL_FRAGMENT_SHADER);
         if (fragmentShader == 0) return 0;

         int program = glCreateProgram();
         glAttachShader(program, vertexShader);
         checkGlError();

         glAttachShader(program, fragmentShader);
         checkGlError();

         glLinkProgram(program);
         checkGlError();

         int[] status = new int[1];
         glGetProgramiv(program, GL_LINK_STATUS, status, 0);
         if (status[0] != GL_TRUE) {
             String error = glGetProgramInfoLog(program);
             Log.d(LOG_TAG, "Error while linking program:\n" + error);
             glDeleteShader(vertexShader);
             glDeleteShader(fragmentShader);
             glDeleteProgram(program);
             return 0;
         }

         return program;
     }

     private int buildShader(String source, int type) {
         int shader = glCreateShader(type);

         glShaderSource(shader, source);
         checkGlError();

         glCompileShader(shader);
         checkGlError();

         int[] status = new int[1];
         glGetShaderiv(shader, GL_COMPILE_STATUS, status, 0);
         if (status[0] != GL_TRUE) {
             String error = glGetShaderInfoLog(shader);
             Log.d(LOG_TAG, "Error while compiling shader:\n" + error);
             glDeleteShader(shader);
             return 0;
         }

         return shader;
     }

     private void checkEglError() {
         int error = mEgl.eglGetError();
         if (error != EGL10.EGL_SUCCESS) {
             Log.w(LOG_TAG, "EGL error = 0x" + Integer.toHexString(error));
         }
     }

     private void checkGlError() {
         int error = glGetError();
         if (error != GL_NO_ERROR) {
             Log.w(LOG_TAG, "GL error = 0x" + Integer.toHexString(error));
         }
     }

     private void finishGL() {
         mEgl.eglDestroyContext(mEglDisplay, mEglContext);
         mEgl.eglDestroySurface(mEglDisplay, mEglSurface);
     }

     private void checkCurrent() {
         if (!mEglContext.equals(mEgl.eglGetCurrentContext()) ||

         !mEglSurface.equals(mEgl.eglGetCurrentSurface(EGL10.EGL_DRAW))) {
             if (!mEgl.eglMakeCurrent(mEglDisplay, mEglSurface, mEglSurface, mEglContext)) {
                 throw new RuntimeException("eglMakeCurrent failed " + GLUtils.getEGLErrorString(mEgl.eglGetError()));
             }
         }
     }

     private void initGL() {
         mEgl = (EGL10) EGLContext.getEGL();

         mEglDisplay = mEgl.eglGetDisplay(EGL10.EGL_DEFAULT_DISPLAY);
         if (mEglDisplay == EGL10.EGL_NO_DISPLAY) {
             throw new RuntimeException("eglGetDisplay failed "
                     + GLUtils.getEGLErrorString(mEgl.eglGetError()));
         }

         int[] version = new int[2];
         if (!mEgl.eglInitialize(mEglDisplay, version)) {
             throw new RuntimeException("eglInitialize failed " +
                     GLUtils.getEGLErrorString(mEgl.eglGetError()));
         }

         mEglConfig = chooseEglConfig();
         if (mEglConfig == null) {
             throw new RuntimeException("eglConfig not initialized");
         }

         mEglContext = createContext(mEgl, mEglDisplay, mEglConfig);

         mEglSurface = mEgl.eglCreateWindowSurface(mEglDisplay, mEglConfig, mSurface, null);

         if (mEglSurface == null || mEglSurface == EGL10.EGL_NO_SURFACE)
         {
             int error = mEgl.eglGetError();
             if (error == EGL10.EGL_BAD_NATIVE_WINDOW) {
                 Log.e(LOG_TAG, "createWindowSurface returned EGL_BAD_NATIVE_WINDOW.");
                 return;
             }
             throw new RuntimeException("createWindowSurface failed "
                     + GLUtils.getEGLErrorString(error));
         }

         if (!mEgl.eglMakeCurrent(mEglDisplay, mEglSurface, mEglSurface, mEglContext)) {
             throw new RuntimeException("eglMakeCurrent failed "
                     + GLUtils.getEGLErrorString(mEgl.eglGetError()));
         }

         mGL = mEglContext.getGL();
     }


     EGLContext createContext(EGL10 egl, EGLDisplay eglDisplay, EGLConfig eglConfig) {
         int[] attrib_list = { EGL_CONTEXT_CLIENT_VERSION, 2, EGL10.EGL_NONE };
         return egl.eglCreateContext(eglDisplay, eglConfig, EGL10.EGL_NO_CONTEXT, attrib_list);
     }

     private EGLConfig chooseEglConfig() {
         int[] configsCount = new int[1];
         EGLConfig[] configs = new EGLConfig[1];
         int[] configSpec = getConfig();
         if (!mEgl.eglChooseConfig(mEglDisplay, configSpec, configs, 1, configsCount)) {
             throw new IllegalArgumentException("eglChooseConfig failed " +
                     GLUtils.getEGLErrorString(mEgl.eglGetError()));
         } else if (configsCount[0] > 0) {
             return configs[0];
         }
         return null;
     }

     private int[] getConfig() {
         return new int[] {
                 EGL10.EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
                 EGL10.EGL_RED_SIZE, 8,
                 EGL10.EGL_GREEN_SIZE, 8,
                 EGL10.EGL_BLUE_SIZE, 8,
                 EGL10.EGL_ALPHA_SIZE, 8,
                 EGL10.EGL_DEPTH_SIZE, 0,
                 EGL10.EGL_STENCIL_SIZE, 0,
                 EGL10.EGL_NONE
         };
     }

     void finish() {
         mFinished = true;
     }
 }