The Android wrapper for SDL2 defines
SDLActivity, which automatically sets a subclass of
SDLSurface) as its
contentView. Note by
SDLSurface I am referring to the Java class; I don't mean the SDL-internal
What I'm trying to do is render my SDL content alongside a video that is being output onto another (stock standard)
SurfaceView by ExoPlayer. The aim is to have the video in the background and the SDL content as an overlay with transparent areas (through which the video is visible).
The Android docs seem to suggest that
SurfaceViews are considered transparent, and I am able to layer a
View with a semi-transparent background colour (and even the video) on top of my SDL content, but anything I render behind is invisible, because the SDLSurface's background is opaque black.
My renderer (SDL_gpu) is theoretically clearing the context every frame with a transparent colour (0,0,0,0) and the background colour is an opaque black even if I don't render anything at all. Changing the background colour to e.g. (50,50,50,50) again produces an opaque colour, not the expected semi-transparent one.
- Is there are
WindowFlag or similar that I'm missing to allow the
SDLSurface to have a transparent background?
- Would it help to try to get a transparent background working in a desktop environment (I saw some other older threads asking about this in that context)?