Sdl_srcalpha

SDL Development
1

Does the SDL_SRCALPHA flag in the the SDL_surface structure indicate that
per-surface alpha is used in blits or alpha channel? Or is it active when
one of the two is set with SDL_SetAlpha() (and the surface can have
alpha…)?–
Marco Iannaccone @Marco_Iannaccone
ICQ: 18748121 MetalCoder

"What is real? How do you define real? If you’re talking about your
senses, what you feel, taste, smell, or see, then all you’re talking about
are electrical signals interpreted by your brain."
Morpheus - The Matrix

2

Does the SDL_SRCALPHA flag in the the SDL_surface structure indicate that
per-surface alpha is used in blits or alpha channel? Or is it active when
one of the two is set with SDL_SetAlpha() (and the surface can have
alpha…)?

Check out:
http://www.libsdl.org/docs/sdlsetalpha.html

RGBA in the description refers to any surface format with an alpha channel.

See ya!
-Sam Lantinga, Lead Programmer, Loki Entertainment Software

3

Does the SDL_SRCALPHA flag in the the SDL_surface structure indicate that
per-surface alpha is used in blits or alpha channel? Or is it active when
one of the two is set with SDL_SetAlpha() (and the surface can have
alpha…)?

the per-surface alpha is used when there is no alpha channel (in other words,
when format->Amask == 0)