SDL_LockSurface - Man Page

#include <SDL3/SDL_surface.h>

bool SDL_LockSurface(SDL_Surface *surface);

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.

surface

the SDL_Surface structure to be locked.

for more information.

This function is not thread safe. The locking referred to by this function is making the pixels available for direct access, not thread-safe locking.

This function is available since SDL 3.2.0.

SDL_MUSTLOCK(3), SDL_UnlockSurface(3)

SDL_SetSurfaceRLE(3), SDL_UnlockSurface(3).