GLSurfaceView - how to make translucent background

Question

I try to render using GLSurfaceView, and by docs I set format:

getHolder().setFormat(PixelFormat.TRANSLUCENT);

The I use GLSurfaceView.Rend

Answer 1

You need RGBA 8888 pixel format for translucency:

private void init( boolean translucent, int depth, int stencil )
{
    /* By default, GLSurfaceView() creates a RGB_565 opaque surface.
     * If we want a translucent one, we should change the surface's
     * format here, using PixelFormat.TRANSLUCENT for GL Surfaces
     * is interpreted as any 32-bit surface with alpha by SurfaceFlinger.
     */
    this.getHolder().setFormat( PixelFormat.RGB_565 );
    if ( translucent )
    {
        this.getHolder().setFormat( PixelFormat.TRANSLUCENT );
    }

    setEGLContextFactory( new ContextFactory() );

    /* We need to choose an EGLConfig that matches the format of
     * our surface exactly. This is going to be done in our
     * custom config chooser. See ConfigChooser class definition
     * below.
     */
    setEGLConfigChooser( translucent ?
                         new ConfigChooser( 8, 8, 8, 8, depth, stencil ) :
                         new ConfigChooser( 5, 6, 5, 0, depth, stencil ) );

    setRenderer( new Renderer() );
}