(This is the documentation for SDL3, which is the current stable version. SDL2 was the previous version!)

SDL_GL_SetSwapInterval

Set the swap interval for the current OpenGL context.

Header File

Syntax

bool SDL_GL_SetSwapInterval(int interval);

Function Parameters

int

interval

0 for immediate updates, 1 for updates synchronized with the vertical retrace, -1 for adaptive vsync.

Return Value

(bool) Returns true on success or false on failure; call SDL_GetError() for more information.

Remarks

Some systems allow specifying -1 for the interval, to enable adaptive vsync. Adaptive vsync works the same as vsync, but if you've already missed the vertical retrace for a given frame, it swaps buffers immediately, which might be less jarring for the user during occasional framerate drops. If an application requests adaptive vsync and the system does not support it, this function will fail and return false. In such a case, you should probably retry the call with 1 for the interval.

Adaptive vsync is implemented for some glX drivers with GLX_EXT_swap_control_tear, and for some Windows drivers with WGL_EXT_swap_control_tear.

Read more on the Khronos wiki: https://www.khronos.org/opengl/wiki/Swap_Interval#Adaptive_Vsync

Thread Safety

This function should only be called on the main thread.

Version

This function is available since SDL 3.1.3.