@Override
    public void readFrameBufferWithFormat(FrameBuffer fb, ByteBuffer byteBuf, Image.Format format) {
        GLImageFormat glFormat = texUtil.getImageFormatWithError(format, false);
        readFrameBufferWithGLFormat(fb, byteBuf, glFormat.format, glFormat.dataType);
    }
Copy the source buffer to the destination buffer, including both color
and depth.

@param src the source buffer (unaffected)
@param dst the destination buffer
jme3-core/src/main/java/com/jme3/renderer/opengl/GLRenderer.java