Get the size of a window's client area.
int SDL_GetWindowSize(SDL_Window *window, int *w, int *h);
|the window to query the width and height from
|a pointer filled in with the width of the window, may be NULL
|a pointer filled in with the height of the window, may be NULL
Returns 0 on success or a negative error code on failure; call SDL_GetError() for more information.
NULL can safely be passed as the
h parameter if the width or height value is not desired.
The window pixel size may differ from its window coordinate size if the window is on a high pixel density display. Use SDL_GetWindowSizeInPixels() or SDL_GetRenderOutputSize() to get the real client area size in pixels.
This function is available since SDL 3.0.0.