Function fermium::surface::SDL_LockSurface [−][src]
pub unsafe extern "C" fn SDL_LockSurface(surface: *mut SDL_Surface) -> c_int
Sets up a surface for directly accessing the pixels.
Between calls to SDL_LockSurface
/ SDL_UnlockSurface
, you can
write to and read from surface->pixels
, using the pixel format stored
in surface->format
. Once you are done accessing the surface, you
should use SDL_UnlockSurface
to release it.
Not all surfaces require locking. If
SDL_MUSTLOCK(surface)
evaluates to 0, then you can
read and write to the surface at any time, and the pixel format of the
surface will not change.
No operating system or library calls should be made between lock/unlock pairs, as critical system locks may be held during this time.
SDL_LockSurface
returns 0, or -1 if the surface couldn’t be locked.