Set an additional alpha value used in blit operations.
When this surface is blitted, during the blit operation the source alpha value is modulated by this alpha value according to the following formula:
srcA = srcA* (alpha / 255)
the SDL_Surface structure to update.
the alpha value multiplied into blit operations.
true on success or false on failure; call SDL_GetError() for more information.
SDL_GetSurfaceAlphaMod SDL_SetSurfaceColorMod
See Implementation
Set an additional alpha value used in blit operations.
When this surface is blitted, during the blit operation the source alpha value is modulated by this alpha value according to the following formula:
srcA = srcA* (alpha / 255)