###### (This is the legacy documentation for SDL2, the previous stable version; [SDL3](https://wiki.libsdl.org/SDL3/) is the current stable version.) # SDL_GL_GetSwapInterval Get the swap interval for the current OpenGL context. ## Header File Defined in [SDL_video.h](https://github.com/libsdl-org/SDL/blob/SDL2/include/SDL_video.h) ## Syntax ```c int SDL_GL_GetSwapInterval(void); ``` ## Return Value (int) Returns 0 if there is no vertical retrace synchronization, 1 if the buffer swap is synchronized with the vertical retrace, and -1 if late swaps happen immediately instead of waiting for the next retrace; call [SDL_GetError](SDL_GetError)() for more information. ## Remarks If the system can't determine the swap interval, or there isn't a valid current context, this function will return 0 as a safe default. ## Version This function is available since SDL 2.0.0. ## See Also - [SDL_GL_SetSwapInterval](SDL_GL_SetSwapInterval) ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryVideo](CategoryVideo)