Man page - sdl_getwindowopacity(3)

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Package: libsdl3-doc
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SDL_GetWindowOpacity - Get the opacity of a window.

Defined in SDL3/SDL_video.h

#include "SDL3/SDL.h"

float SDL_GetWindowOpacity(SDL_Window *window);

If transparency isn’t supported on this platform, opacity will be returned as 1.0f without error.

window

the window to get the current opacity value from.

Returns the opacity, (0.0f - transparent, 1.0f - opaque), or -1.0f on failure; call SDL_GetError () for more information.

This function should only be called on the main thread.

This function is available since SDL 3.2.0.