Get the size of a window's client area.
Defined in SDL_video.h
| window | the window to query the width and height from |
| w | a pointer filled in with the width of the window, in screen coordinates, may be NULL |
| h | a pointer filled in with the height of the window, in screen coordinates, may be NULL |
NULL can safely be passed as the w or h parameter if the width or height value is not desired.
The window size in screen coordinates may differ from the size in pixels, if the window was created with SDL_WINDOW_ALLOW_HIGHDPI on a platform with high-dpi support (e.g. iOS or macOS). Use SDL_GL_GetDrawableSize(), SDL_Vulkan_GetDrawableSize(), or SDL_GetRendererOutputSize() to get the real client area size in pixels.
This function is available since SDL 2.0.0.