My game engine takes a simplistic approach to supporting multiple windows with a single OpenGL context in the following way:
Activate OpenGL context on window 1 Draw scene in to window 1 Activate OpenGL context on window 2 Draw scene in to window 2 Activate OpenGL context on window 3 Draw scene in to window 3 For all Windows SwapBuffers
This works fine with monitors of the same refresh rate (with VSync on or off), and now I’m experimenting with monitors of different refresh rates. With V-Sync disabled, as long as the engine can produce enough frames, a window on a higher refresh rate monitor won’t get slowed down by a window on a slower refresh rate monitor, as SwapBuffers doesn’t block. With V-Sync enabled, SwapBuffers will sync to the slowest monitor and windows on faster monitors will get slowed down.
If there any way of fixing this without resorting to a thread and OpenGL context for each window? I was thinking along the lines of a non-blocking SwapBuffers and checking if a window is going through a swap, and if not then swapping it’s buffers or something?