How to enable/disable Vsync with SDL3 GPU (no SDL_Renderer)

SDL Development
1

Hi, I just switched my whole engine rendering system from BGFX to SDL3 GPU and one of the points I don’t know how to convert from one API to the other, is how to enable/disable VSync. I know it exists the

SDL_SetRenderVSync

But I’m not using the SDL_Renderer, I’m using the SDL_GPU API, so that won’t help, do you guys know how to achieve this?

Thanks.

2

The swapchain parameters are what determines if vsync is on/off, and what kind of vsync to use if it’s on.

You use SDL_SetGPUSwapchainParameters() to change it.

Something like:

// In your setup code somewhere:

// Can check to see what other swapchain compositions are supported with SDL_WindowSupportsGPUSwapchainComposition()
SDL_GPUSwapchainComposition swapchainComposition = SDL_GPU_SWAPCHAINCOMPOSITION_SDR;

// Check to see if MAILBOX present mode is supported
bool supportsMailbox = SDL_WindowSupportsGPUPresentMode(gpuDevice, window, SDL_GPU_PRESENTMODE_MAILBOX);

// after claiming the window
SDL_SetGPUSwapchainParameters(gpuDevice, window, swapchainComposition, supportsMailbox ? SDL_GPU_PRESENTMODE_MAILBOX : SDL_GPU_PRESENTMODE_VSYNC);

...

// elsewhere

bool ToggleVsync(bool vsync) {
    SDL_GPUPresentMode presentMode = SDL_GPU_PRESENTMODE_IMMEDIATE; // vsync OFF
    if(vsync) {
        presentMode = supportsMailbox ? SDL_GPU_PRESENTMODE_MAILBOX : SDL_GPU_PRESENTMODE_VSYNC;
    }

    if(!SDL_SetGPUSwapchainParameters(gpuDevice, window, swapchainComposition, presentMode) {
        // failure
        return false;
    }
    return true;
}
2 Likes
3

That is perfect, exactly what I needed, thank you so much!