SDL_PremultiplyAlpha - Man Page
Premultiply the alpha on a block of pixels.
Header File
Defined in SDL3/SDL_surface.h
Synopsis
#include "SDL3/SDL.h" bool SDL_PremultiplyAlpha(int width, int height, SDL_PixelFormat src_format, const void *src, int src_pitch, SDL_PixelFormat dst_format, void *dst, int dst_pitch, bool linear);
Description
This is safe to use with src == dst, but not for other overlapping areas.
Function Parameters
- width
the width of the block to convert, in pixels.
- height
the height of the block to convert, in pixels.
- src_format
an SDL_PixelFormat
value of the src pixels format.- src
a pointer to the source pixels.
- src_pitch
the pitch of the source pixels, in bytes.
- dst_format
an SDL_PixelFormat
value of the dst pixels format.- dst
a pointer to be filled in with premultiplied pixel data.
- dst_pitch
the pitch of the destination pixels, in bytes.
- linear
true to convert from sRGB to linear space for the alpha multiplication, false to do multiplication in sRGB space.
Return Value
Returns true on success or false on failure; call
SDL_GetError () for more information.
Thread Safety
The same destination pixels should not be used from two threads at once. It is safe to use the same source pixels from multiple threads.
Availability
This function is available since SDL 3.2.0.