Provided by: libsdl3-doc_3.2.8+ds-1_all 

NAME
SDL_PremultiplyAlpha - 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.
AVAILABILITY
This function is available since SDL 3.2.0. Simple Directmedia Layer SDL 3.2.8 SDL_PremultiplyAlpha(3)