Is it possible to display PyGame surfaces with controllable alpha? I would like to take a surface with its own per pixel alpha and display it with variable level of translucency without affecting the surface data and keep the transparency intact i.e. the objects on the surface would keep their shapes but their "contents" becoming more or less translucent.
In other words I want to combine per-pixel alpha from the source image with per-surface alpha calculated at the runtime.
After checking both PyGame and SDL documentations I came to conclusion that what I asked wasn't doable in PyGame using standard functions.
SDL docs state that per-pixel alpha and per-surface alpha cannot be combined with the former always taking the precedence. The only way to achieve the effect I want is by writing a code which updates per-pixel alpha values of the source surface before the blit.
PyGame: translucent sprites with per pixel alpha