NAME¶

SDL_PremultiplyAlpha - Premultiply the alpha on a block of pixels.

SYNOPSIS¶

#include "SDL3/SDL.h"

int SDL_PremultiplyAlpha(int width, int height, SDL_PixelFormatEnum src_format, const void *src, int src_pitch, SDL_PixelFormatEnum dst_format, void *dst, int dst_pitch);

DESCRIPTION¶

This is safe to use with src == dst, but not for other overlapping areas.

This function is currently only implemented for

SDL_PIXELFORMAT_ARGB8888 .

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_PixelFormatEnum
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_PixelFormatEnum
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

RETURN VALUE¶

Returns 0 on success or a negative error code on failure; call

SDL_GetError () for more information.

AVAILABILITY¶

This function is available since SDL 3.0.0.