###### (This is the documentation for SDL3, which is the current stable version. [SDL2](https://wiki.libsdl.org/SDL2/) was the previous version!) # SDL_LockSurface Set up a surface for directly accessing the pixels. ## Header File Defined in [](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_surface.h) ## Syntax ```c bool SDL_LockSurface(SDL_Surface *surface); ``` ## Function Parameters | | | | | ---------------------------- | ----------- | ------------------------------------------------------ | | [SDL_Surface](SDL_Surface) * | **surface** | the [SDL_Surface](SDL_Surface) structure to be locked. | ## Return Value (bool) Returns true on success or false on failure; call [SDL_GetError](SDL_GetError)() for more information. ## Remarks Between calls to [SDL_LockSurface](SDL_LockSurface)() / [SDL_UnlockSurface](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](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. ## Version This function is available since SDL 3.1.3. ## See Also - [SDL_MUSTLOCK](SDL_MUSTLOCK) - [SDL_UnlockSurface](SDL_UnlockSurface) ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategorySurface](CategorySurface)