Function sdl2_sys::SDL_SetTextureAlphaMod

source ยท 
pub unsafe extern "C" fn SDL_SetTextureAlphaMod(
    texture: *mut SDL_Texture,
    alpha: Uint8,
) -> c_int
Expand description

Set an additional alpha value multiplied into render copy operations.

When this texture is rendered, during the copy operation the source alpha value is modulated by this alpha value according to the following formula:

srcA = srcA * (alpha / 255)

Alpha modulation is not always supported by the renderer; it will return -1 if alpha modulation is not supported.

\param texture the texture to update \param alpha the source alpha value multiplied into copy operations \returns 0 on success or a negative error code on failure; call SDL_GetError() for more information.

\since This function is available since SDL 2.0.0.

\sa SDL_GetTextureAlphaMod \sa SDL_SetTextureColorMod