Question

I’m developing application for Android with GLSurfaceView. One moment i have to replace my GLSurfaceView with an image of it in that moment. The question is, how to get an image right? I used this code:

    v.setDrawingCacheEnabled(true);
    v.measure(View.MeasureSpec.makeMeasureSpec(500, View.MeasureSpec.AT_MOST),
            View.MeasureSpec.makeMeasureSpec(500, View.MeasureSpec.AT_MOST));
    v.layout(0, 0, v.getMeasuredWidth(), v.getMeasuredHeight());

    v.buildDrawingCache(true);
    Bitmap b = Bitmap.createBitmap(v.getDrawingCache());
    v.setDrawingCacheEnabled(false); // clear drawing cache
    return b;

but it always return black bitmap.

Maybe we can make something other then Bitmap (which also can be placed to GLSurfaceView)?

Answer 1

I don’t think it works this way with a GLSurfaceView. The framebuffer may live inside the GPU, where it’s not directly accessible on the CPU.

You can use a framebuffer object to render the image to a texture, then use glReadPixels to download the data into a buffer and turn the buffer into a Bitmap.