Android 原生的View渲染到OpenGL GLSurfaceView中，

Posted 2022-11-16 zhangtian6691844

                  
要把android 原生的View渲染到OpenGL GLSurfaceView中，起初想到的是截图的方法，也就是把View截取成bitmap后，再把Bitmap渲染到OpenGL中；但是明显这种方法是不可行的，面对一些高速动态更新的View，只有不停的对view 进行截图才能渲染出原生View的效果。不过经过测试该方法只能渲染直接父类为View的view，也就是只能渲染一层View（如progressbar，没不能添加child的view），当该原生Android View包含很多子view时（也就是根View为FramLayout、或者linearLayout之类），无法实时的监听到View动态改变，OpenGL中只能不停的渲染该view，才能渲染出原生View的效果。但是这样一来不同的渲染会耗费大量的资源，降低应用程序的效率。理想中的话，是监听到了该View的内容或者其子view 的内容发生了变化(如：View中的字幕发生滚动)才进行渲染。
     

步骤一:重写根View
1.设置该View 绘制自己：

setWillNotDraw(false);
 2.监听View的变化，重写View，用ViewTreeObServer来监听，方法如下：

    private void addOnPreDrawListener()
 
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
 
            final ViewTreeObserver mObserver = getViewTreeObserver();
            if (mObserver != null)
                mObserver.addOnPreDrawListener(new OnPreDrawListener()
 
                    @Override
                    public boolean onPreDraw()
                        if (isDirty()) //View或者子view发生变化
                            invalidate();
                        
                        return true;
                    
                );
            
        
    
 3.重写该View的onDraw方法:

    @Override
    protected void onDraw(Canvas canvas)
        try
            if (mSurface != null)
                Canvas surfaceCanvas = mSurface.lockCanvas(null);
                super.dispatchDraw(surfaceCanvas);
                mSurface.unlockCanvasAndPost(surfaceCanvas);
                
                mSurface.release();
                mSurface = null;
                mSurface = new Surface(mSurfaceTexture);
            
         catch (OutOfResourcesException e)
            e.printStackTrace();
        
    
步骤二：GLSurfaceView.Renderer
class CustomRenderer implements GLSurfaceView.Renderer
    int glSurfaceTex;
    private final int GL_TEXTURE_EXTERNAL_OES = 0x8D65;
    long currentTime;
    long previousTime;
    boolean b = false;
    int frameCount = 0;
    DirectDrawer mDirectDrawer;
    ActivityManager activityManager;
    MemoryInfo _memoryInfo;
    
 
    // Fixed values
    private int TEXTURE_WIDTH = 360;
    private int TEXTURE_HEIGHT = 360;
 
    Context context;
    
    private LauncherAppWidgetHostView addedWidgetView;
    
    private SurfaceTexture surfaceTexture = null;
 
    private Surface surface;
 
    float fps;
    
    public CustomRenderer(Context context, LauncherAppWidgetHostView addedWidgetView, Display mDisplay)
        this.context = context;
        this.addedWidgetView = addedWidgetView;
        TEXTURE_WIDTH = mDisplay.getWidth();
        TEXTURE_HEIGHT = mDisplay.getHeight();
        _memoryInfo = new MemoryInfo();
        activityManager = (ActivityManager) context.getApplicationContext().getSystemService(Context.ACTIVITY_SERVICE);
    
    
    @Override
    public void onDrawFrame(GL10 gl)
 
        synchronized (this)
            surfaceTexture.updateTexImage();
        
 
        activityManager.getMemoryInfo(_memoryInfo);
 
        GLES20.glClearColor(0.0f, 0.0f, 1.0f, 1.0f);
        GLES20.glClear(GLES20.GL_DEPTH_BUFFER_BIT | GLES20.GL_COLOR_BUFFER_BIT);
        GLES20.glEnable(GLES20.GL_BLEND);
        GLES20.glBlendFunc(GLES20.GL_ONE, GLES20.GL_ONE_MINUS_SRC_ALPHA);
 
        float[] mtx = new float[16];
        surfaceTexture.getTransformMatrix(mtx);
        mDirectDrawer.draw(mtx);
 
        calculateFps();
        //getAppMemorySize();
        //getRunningAppProcessInfo();
        //Log.v("onDrawFrame", "FPS: " + Math.round(fps) + ", availMem: " + Math.round(_memoryInfo.availMem / 1048576) + "MB");
    
    
    private void getAppMemorySize()
        ActivityManager mActivityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
        android.os.Debug.MemoryInfo[] memoryInfos = mActivityManager.getProcessMemoryInfo(new int[]android.os.Process.myPid());
        int size = memoryInfos[0].dalvikPrivateDirty;
        Log.w("getAppMemorySize", size / 1024 + " MB");
    
 
    
    private void getRunningAppProcessInfo()  
        ActivityManager  mActivityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);  
      
        //获得系统里正在运行的所有进程  
        List<RunningAppProcessInfo> runningAppProcessesList = mActivityManager.getRunningAppProcesses();  
      
        for (RunningAppProcessInfo runningAppProcessInfo : runningAppProcessesList)  
            // 进程ID号  
            int pid = runningAppProcessInfo.pid;  
            // 用户ID  
            int uid = runningAppProcessInfo.uid;  
            // 进程名  
            String processName = runningAppProcessInfo.processName;  
            // 占用的内存  
            int[] pids = new int[] pid;  
            Debug.MemoryInfo[] memoryInfo = mActivityManager.getProcessMemoryInfo(pids);  
            int memorySize = memoryInfo[0].dalvikPrivateDirty;  
      
            System.out.println("processName="+processName+",currentPid: "+  "pid= " +android.os.Process.myPid()+"----------->"+pid+",uid="+uid+",memorySize="+memorySize+"kb");  
          
    
    
    @Override
    public void onSurfaceCreated(GL10 gl, EGLConfig config)
 
        surface = null;
        surfaceTexture = null;
 
        glSurfaceTex = Engine_CreateSurfaceTexture(TEXTURE_WIDTH, TEXTURE_HEIGHT);
        Log.d("GLES20Ext", "glSurfaceTex" + glSurfaceTex);
        if (glSurfaceTex > 0)
            surfaceTexture = new SurfaceTexture(glSurfaceTex);
            surfaceTexture.setDefaultBufferSize(TEXTURE_WIDTH, TEXTURE_HEIGHT);
            surface = new Surface(surfaceTexture);
            addedWidgetView.setSurface(surface);
            addedWidgetView.setSurfaceTexture(surfaceTexture);
            //addedWidgetView.setSurfaceTexture(surfaceTexture);
            mDirectDrawer = new DirectDrawer(glSurfaceTex);
        
    
 
    float calculateFps()
 
        frameCount++;
        if (!b)
            b = true;
            previousTime = System.currentTimeMillis();
        
        long intervalTime = System.currentTimeMillis() - previousTime;
 
        if (intervalTime >= 1000)
            b = false;
            fps = frameCount / (intervalTime / 1000f);
            frameCount = 0;
            Log.w("calculateFps", "FPS: " + fps);
        
 
        return fps;
    
 
    int Engine_CreateSurfaceTexture(int width, int height)
        /*
         * Create our texture. This has to be done each time the surface is
         * created.
         */
 
        int[] textures = new int[1];
        GLES20.glGenTextures(1, textures, 0);
 
        glSurfaceTex = textures[0];
 
        if (glSurfaceTex > 0)
            GLES20.glBindTexture(GL_TEXTURE_EXTERNAL_OES, glSurfaceTex);
 
            // Notice the use of GL_TEXTURE_2D for texture creation
            GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_RGB, width, height, 0, GLES20.GL_RGB, GLES20.GL_UNSIGNED_BYTE, null);
 
            GLES20.glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);
            GLES20.glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_NEAREST);
 
            GLES20.glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE);
            GLES20.glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE);
        
        return glSurfaceTex;
    
 
    @Override
    public void onSurfaceChanged(GL10 gl, int width, int height)
        
    

public class DirectDrawer  
   private final String vertexShaderCode =  
           "attribute vec4 vPosition;" +  
           "attribute vec2 inputTextureCoordinate;" +  
           "varying vec2 textureCoordinate;" +  
           "void main()" +  
           ""+  
               "gl_Position = vPosition;"+  
               "textureCoordinate = inputTextureCoordinate;" +  
           "";  
 
   private final String fragmentShaderCode =  
           "#extension GL_OES_EGL_image_external : require\\n"+  
           "precision mediump float;" +  
           "varying vec2 textureCoordinate;\\n" +  
           "uniform samplerExternalOES s_texture;\\n" +  
           "void main() " +  
           "  gl_FragColor = texture2D( s_texture, textureCoordinate );\\n" +  
           "";  
 
   private FloatBuffer vertexBuffer, textureVerticesBuffer;  
   private ShortBuffer drawListBuffer;  
   private final int mProgram;  
   private int mPositionHandle;  
   private int mTextureCoordHandle;  
 
   private short drawOrder[] = 0, 1, 2, 0, 2, 3 ; // order to draw vertices  
 
   // number of coordinates per vertex in this array  
   private static final int COORDS_PER_VERTEX = 2;  
 
   private final int vertexStride = COORDS_PER_VERTEX * 4; // 4 bytes per vertex  
 
   static float squareCoords[] =  
      -1.0f,  0.0f,  
      -1.0f, -2.2f,  
       1.0f, -2.2f,  
       1.0f,  0.0f,  
   ;  
 
   static float textureVertices[] =  
           0f,  0f,    
           0f,  1f,  
        1f,  1f,  
        1f,  0f,   
   ;  
 
   private int texture;  
 
   public DirectDrawer(int texture)  
     
       this.texture = texture;  
       // initialize vertex byte buffer for shape coordinates  
       ByteBuffer bb = ByteBuffer.allocateDirect(squareCoords.length * 4);  
       bb.order(ByteOrder.nativeOrder());  
       vertexBuffer = bb.asFloatBuffer();  
       vertexBuffer.put(squareCoords);  
       vertexBuffer.position(0);  
 
       // initialize byte buffer for the draw list  
       ByteBuffer dlb = ByteBuffer.allocateDirect(drawOrder.length * 2);  
       dlb.order(ByteOrder.nativeOrder());  
       drawListBuffer = dlb.asShortBuffer();  
       drawListBuffer.put(drawOrder);  
       drawListBuffer.position(0);  
 
       ByteBuffer bb2 = ByteBuffer.allocateDirect(textureVertices.length * 4);  
       bb2.order(ByteOrder.nativeOrder());  
       textureVerticesBuffer = bb2.asFloatBuffer();  
       textureVerticesBuffer.put(textureVertices);  
       textureVerticesBuffer.position(0);  
 
       int vertexShader    = loadShader(GLES20.GL_VERTEX_SHADER, vertexShaderCode);  
       int fragmentShader  = loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentShaderCode);  
 
       mProgram = GLES20.glCreateProgram();             // create empty OpenGL ES Program  
       GLES20.glAttachShader(mProgram, vertexShader);   // add the vertex shader to program  
       GLES20.glAttachShader(mProgram, fragmentShader); // add the fragment shader to program  
       GLES20.glLinkProgram(mProgram);                  // creates OpenGL ES program executables  
     
 
   public void draw(float[] mtx)  
     
       GLES20.glUseProgram(mProgram);  
 
       GLES20.glActiveTexture(GLES20.GL_TEXTURE0);  
       GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, texture);  
 
       // get handle to vertex shader's vPosition member  
       mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");  
 
       // Enable a handle to the triangle vertices  
       GLES20.glEnableVertexAttribArray(mPositionHandle);  
 
       // Prepare the <insert shape here> coordinate data  
       GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false, vertexStride, vertexBuffer);  
 
       mTextureCoordHandle = GLES20.glGetAttribLocation(mProgram, "inputTextureCoordinate");  
       GLES20.glEnableVertexAttribArray(mTextureCoordHandle);  
         
        // textureVerticesBuffer.clear();
        // textureVerticesBuffer.put( transformTextureCoordinates(
        // textureVertices, mtx ));
        // textureVerticesBuffer.position(0);
       
       GLES20.glVertexAttribPointer(mTextureCoordHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false, vertexStride, textureVerticesBuffer);  
 
       GLES20.glDrawElements(GLES20.GL_TRIANGLES, drawOrder.length, GLES20.GL_UNSIGNED_SHORT, drawListBuffer);  
 
       // Disable vertex array  
       GLES20.glDisableVertexAttribArray(mPositionHandle);  
       GLES20.glDisableVertexAttribArray(mTextureCoordHandle);  
     
     
   private  int loadShader(int type, String shaderCode)  
 
       // create a vertex shader type (GLES20.GL_VERTEX_SHADER)  
       // or a fragment shader type (GLES20.GL_FRAGMENT_SHADER)  
       int shader = GLES20.glCreateShader(type);  
 
       // add the source code to the shader and compile it  
       GLES20.glShaderSource(shader, shaderCode);  
       GLES20.glCompileShader(shader);  
 
       return shader;  
     
   private float[] transformTextureCoordinates( float[] coords, float[] matrix)  
               
      float[] result = new float[ coords.length ];          
      float[] vt = new float[4];        
 
      for ( int i = 0 ; i < coords.length ; i += 2 )  
          float[] v = coords[i], coords[i+1], 0 , 1  ;  
          Matrix.multiplyMV(vt, 0, matrix, 0, v, 0);  
          result[i] = vt[0];  
          result[i+1] = vt[1];  
       
      return result;  
     
 
步骤三：配置GLSurfaceView：
GLSurfaceView glSurfaceView = new GLSurfaceView(getApplicationContext());
// Setup the surface view for drawing to
 
glSurfaceView.setEGLContextClientVersion(2);
glSurfaceView.setEGLConfigChooser(8, 8, 8, 8, 16, 0);        
glSurfaceView.setRenderer(renderer);
//glSurfaceView.setZOrderOnTop(true);
 
// Add our WebView to the Android View hierarchy
glSurfaceView.setLayoutParams(new FrameLayout.LayoutParams(FrameLayout.LayoutParams.MATCH_PARENT, FrameLayout.LayoutParams.MATCH_PARENT));