如何使用 ImageReader 读取 OpenGL 曲面？

Question

I'm trying to draw something use OpenGL ES 1.0, the rendering to screen works good. Then I want to use ImageReader to get the image data from surface, but its callback ImageReader.OnImageAvailableListener is not called at all while rendering, what's wrong about my code?

public class ImageReaderActivity extends ActionBarActivity implements SurfaceHolder.Callback, Runnable {

private SurfaceView mSurfaceView;
private SurfaceHolder mSurfaceHolder;
private Surface mSurface;
private int mWidth, mHeight;
private boolean mRunning = false;

private ImageReader mImageReader;

private OpenGLDrawer mOpenGLDrawer;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_imagereader);
    mSurfaceView = findViewById(R.id.surface_view);
    mSurfaceHolder = mSurfaceView.getHolder();
    mSurfaceHolder.addCallback(this);
}

@Override
public void surfaceCreated(SurfaceHolder holder) {

}

@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
    mWidth = width;
    mHeight = height;
    mImageReader = ImageReader.newInstance(width, height, PixelFormat.RGBA_8888, 1);
    mImageReader.setOnImageAvailableListener(mOnImageAvailableListener, null);
    mSurface = mImageReader.getSurface();
    new Thread(this).start();
}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {
    mRunning = false;
}

@Override
public void run() {
    EGL10 egl = (EGL10) EGLContext.getEGL();
    EGLDisplay dpy = egl.eglGetDisplay(EGL10.EGL_DEFAULT_DISPLAY);
    int[] version = new int[2];
    egl.eglInitialize(dpy, version);

    int[] configSpec = {
            EGL10.EGL_RED_SIZE,      5,
            EGL10.EGL_GREEN_SIZE,    6,
            EGL10.EGL_BLUE_SIZE,     5,
            EGL10.EGL_DEPTH_SIZE,   16,
            EGL10.EGL_NONE
    };

    EGLConfig[] configs = new EGLConfig[1];
    int[] num_config = new int[1];

    egl.eglChooseConfig(dpy, configSpec, configs, 1, num_config);
    EGLConfig config = configs[0];

    EGLContext context = egl.eglCreateContext(dpy, config,
            EGL10.EGL_NO_CONTEXT, null);

    EGLSurface drawSurface = egl.eglCreateWindowSurface(dpy, config, mSurfaceHolder, null);
    EGLSurface readSurface = egl.eglCreateWindowSurface(dpy, config, mSurface, null);

    egl.eglMakeCurrent(dpy, drawSurface, readSurface, context);

    GL10 gl = (GL10)context.getGL();

    mOpenGLDrawer = new OpenGLDrawer();
    mOpenGLDrawer.setSize(gl, mWidth, mHeight);

    mRunning = true;
    while (mRunning) {
        SystemClock.sleep(333);
        synchronized (mSurfaceHolder) {
            render(gl);

            egl.eglSwapBuffers(dpy, drawSurface);
        }
    }

    egl.eglMakeCurrent(dpy, EGL10.EGL_NO_SURFACE, EGL10.EGL_NO_SURFACE, EGL10.EGL_NO_CONTEXT);
    egl.eglDestroySurface(dpy, drawSurface);
    egl.eglDestroySurface(dpy, readSurface);
    egl.eglDestroyContext(dpy, context);
    egl.eglTerminate(dpy);
}

private void render(GL10 gl) {
    gl.glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
    gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
    mOpenGLDrawer.draw(gl);
}

private ImageReader.OnImageAvailableListener mOnImageAvailableListener = new ImageReader.OnImageAvailableListener() {
    @Override
    public void onImageAvailable(ImageReader reader) {
        Image image = reader.acquireLatestImage();
        if (image != null) {
            image.close();
        }
    }
};

}

Answer 1

After long time debugging, here is the final working code:

public class ImageReaderActivity extends ActionBarActivity 
        implements SurfaceHolder.Callback, Runnable {
    private static final int MSG_SHOW_SCREENSHOT = 0;
    private static final int MSG_HIDE_SCREENSHOT = 1;

    private SurfaceView mSurfaceView;
    private SurfaceHolder mSurfaceHolder;
    private Surface mSurface;
    private int mWidth, mHeight;
    private boolean mRunning = false;

    private ImageReader mImageReader;

    private OpenGLDrawer mOpenGLDrawer;

    private EGLSurface mDrawSurface;
    private EGLSurface mImageReaderSurface;
    private EGLDisplay mEGLDisplay;
    private EGLContext mEGLContext;

    private FrameLayout mFrameView;
    private ImageView mScreenshotView;

    private volatile boolean mIsCapturing = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_imagereader);
        mSurfaceView = findViewById(R.id.surface_view);
        mSurfaceHolder = mSurfaceView.getHolder();
        mSurfaceHolder.addCallback(this);
        mFrameView = findViewById(R.id.frame);
        mScreenshotView = findViewById(R.id.screenshot);
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {

    }

    @SuppressLint("WrongConstant")
    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        mWidth = width;
        mHeight = height;
        mImageReader = ImageReader.newInstance(width, height, PixelFormat.RGBA_8888,1);
        mImageReader.setOnImageAvailableListener(mOnImageAvailableListener, null);
        mSurface = mImageReader.getSurface();
        new Thread(this).start();
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        mRunning = false;
    }

    @Override
    public void run() {
        // 创建一个EGL实例
        EGL10 egl = (EGL10) EGLContext.getEGL();
        // 传教一个EGLDisplay实例
        mEGLDisplay = egl.eglGetDisplay(EGL10.EGL_DEFAULT_DISPLAY);
        // 初始化EGLDisplay实例
        int[] version = new int[2];
        egl.eglInitialize(mEGLDisplay, version);

        int[] configSpec = {
                EGL14.EGL_RED_SIZE, 8,
                EGL14.EGL_GREEN_SIZE, 8,
                EGL14.EGL_BLUE_SIZE, 8,
                EGL14.EGL_ALPHA_SIZE, 8,
                EGL14.EGL_RENDERABLE_TYPE, EGL14.EGL_OPENGL_ES2_BIT,
                EGL14.EGL_SURFACE_TYPE, EGL14.EGL_WINDOW_BIT,
                EGL_RECORDABLE_ANDROID, 1,
                EGL14.EGL_NONE
        };

        EGLConfig[] configs = new EGLConfig[1];
        int[] num_config = new int[1];
        // 选择config创建OpenGL运行环境
        egl.eglChooseConfig(mEGLDisplay, configSpec, configs, 1, num_config);
        EGLConfig config = configs[0];

        int ctxAttr[] = {
                EGL14.EGL_CONTEXT_CLIENT_VERSION, 1,// 0x3098
                EGL14.EGL_NONE
        };

        mEGLContext = egl.eglCreateContext(mEGLDisplay, config,
                EGL10.EGL_NO_CONTEXT, ctxAttr);
        // 创建新的surface
        mDrawSurface = egl.eglCreateWindowSurface(mEGLDisplay, config, mSurfaceHolder, null);
        mImageReaderSurface = egl.eglCreateWindowSurface(mEGLDisplay, config, mSurface, null);

        // 将OpenGL环境设置为当前
        egl.eglMakeCurrent(mEGLDisplay, mDrawSurface, mDrawSurface, mEGLContext);
        // 获取当前OpenGL画布
        GL10 gl = (GL10)mEGLContext.getGL();

        mOpenGLDrawer = new OpenGLDrawer();
        mOpenGLDrawer.setSize(gl, mWidth, mHeight);

        mRunning = true;
        while (mRunning) {
            synchronized (mSurfaceHolder) {
                render(gl);

                // 显示绘制结果到屏幕上
                egl.eglSwapBuffers(mEGLDisplay, mDrawSurface);

                egl.eglMakeCurrent(mEGLDisplay, mImageReaderSurface, mImageReaderSurface, mEGLContext);

                render(gl);

                egl.eglSwapBuffers(mEGLDisplay, mImageReaderSurface);

                egl.eglMakeCurrent(mEGLDisplay, mDrawSurface, mDrawSurface, mEGLContext);
            }
            SystemClock.sleep(333);
        }

        egl.eglMakeCurrent(mEGLDisplay, EGL10.EGL_NO_SURFACE, EGL10.EGL_NO_SURFACE, EGL10.EGL_NO_CONTEXT);
        egl.eglDestroySurface(mEGLDisplay, mDrawSurface);
        egl.eglDestroyContext(mEGLDisplay, mEGLContext);
        egl.eglTerminate(mEGLDisplay);
    }

    public void onTakeScreenshotClick(View view) {
        synchronized (this) {
            mIsCapturing = true;
        }
    }

    private void render(GL10 gl) {
        gl.glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
        gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
        mOpenGLDrawer.draw(gl);
    }

    private ImageReader.OnImageAvailableListener mOnImageAvailableListener = new ImageReader.OnImageAvailableListener() {
        @Override
        public void onImageAvailable(ImageReader reader) {
            Log.d("reader", "onImageAvailable(ImageReader reader)");

            Image image = reader.acquireNextImage();
            if (image != null) {
                Log.d("reader", "acquireLatestImage()");

                synchronized (this) {
                    if (mIsCapturing) {
                        mIsCapturing = false;

                        int width = image.getWidth();
                        int height = image.getHeight();
                        final Image.Plane[] planes = image.getPlanes();
                        final ByteBuffer buffer = planes[0].getBuffer();
                        int pixelStride = planes[0].getPixelStride();
                        int rowStride = planes[0].getRowStride();
                        int rowPadding = rowStride - pixelStride * width;
                        Bitmap bitmap = Bitmap.createBitmap(width + rowPadding / pixelStride, height, Bitmap.Config.ARGB_8888);
                        bitmap.copyPixelsFromBuffer(buffer);
                        final Bitmap bmp = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
                        Canvas canvas = new Canvas(bmp);
                        final Rect src = new Rect(0,0, bitmap.getWidth(), bitmap.getHeight());
                        final RectF dst = new RectF(0,0, width, height);
                        canvas.drawBitmap(bitmap, src, dst, null);

                        mScreenshotView.post(() -> mScreenshotView.setImageBitmap(bmp));
                        mHandler.sendEmptyMessage(MSG_SHOW_SCREENSHOT);
                    }
                }

                image.close();
            }
        }
    };

    private Handler mHandler = new Handler(new Handler.Callback() {
        @Override
        public boolean handleMessage(@NonNull Message msg) {
            switch (msg.what) {
                case MSG_SHOW_SCREENSHOT:
                    mFrameView.setVisibility(View.VISIBLE);
                    mHandler.sendEmptyMessageDelayed(MSG_HIDE_SCREENSHOT, 3000);
                    break;

                case MSG_HIDE_SCREENSHOT:
                    mFrameView.setVisibility(View.GONE);
                    break;

                default:
                    break;
            }

            return false;
        }
    });
}