###### (This is the documentation for SDL3, which is the current stable version. [SDL2](https://wiki.libsdl.org/SDL2/) was the previous version!) # SDL_SetWindowShape Set the shape of a transparent window. ## Header File Defined in [](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_video.h) ## Syntax ```c bool SDL_SetWindowShape(SDL_Window *window, SDL_Surface *shape); ``` ## Function Parameters | | | | | ---------------------------- | ---------- | -------------------------------------------------------------------------------------- | | [SDL_Window](SDL_Window) * | **window** | the window. | | [SDL_Surface](SDL_Surface) * | **shape** | the surface representing the shape of the window, or NULL to remove any current shape. | ## Return Value (bool) Returns true on success or false on failure; call [SDL_GetError](SDL_GetError)() for more information. ## Remarks This sets the alpha channel of a transparent window and any fully transparent areas are also transparent to mouse clicks. If you are using something besides the SDL render API, then you are responsible for drawing the alpha channel of the window to match the shape alpha channel to get consistent cross-platform results. The shape is copied inside this function, so you can free it afterwards. If your shape surface changes, you should call [SDL_SetWindowShape](SDL_SetWindowShape)() again to update the window. This is an expensive operation, so should be done sparingly. The window must have been created with the [SDL_WINDOW_TRANSPARENT](SDL_WINDOW_TRANSPARENT) flag. ## Version This function is available since SDL 3.1.3. ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryVideo](CategoryVideo)