Windows & displaysSDL 3.2
SDL_GetWindowSizeInPixels
Reads the size of the window's drawing area in real PIXELS: what OpenGL, Vulkan and SDL_GPU draw into.
Signature
bool SDL_GetWindowSizeInPixels(SDL_Window *window, int *w, int *h);
How it works
Pass this size to glViewport, to the Vulkan swapchain extent, or use it to size an offscreen texture. It changes when the window is resized or dragged to a monitor with another density; the event SDL_EVENT_WINDOW_PIXEL_SIZE_CHANGED tells you when.
Parameters
windowSDL_Window *
The window to measure.
wint *
Where to write the width in pixels, or NULL.
hint *
Where to write the height in pixels, or NULL.
Return value
true on success, false on failure.
Tips & pitfalls
A minimized window can report 0×0. Skip the frame: a swapchain or a projection with 0 height is invalid.
Example
example.cpp
1if (e.type == SDL_EVENT_WINDOW_PIXEL_SIZE_CHANGED) {
2 int pw, ph;
3 SDL_GetWindowSizeInPixels(window, &pw, &ph);
4 glViewport(0, 0, pw, ph);
5}