SDL_PremultiplyAlpha

Premultiply the alpha on a block of pixels.

Syntax

int SDL_PremultiplyAlpha(int width, int height,
                         Uint32 src_format,
                         const void * src, int src_pitch,
                         Uint32 dst_format,
                         void * dst, int dst_pitch);

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.

Remarks

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

This function is currently only implemented for SDL_PIXELFORMAT_ARGB8888.

Version

This function is available since SDL 2.0.18.

CategoryAPI

[ edit | delete | history | feedback | raw ]

All wiki content is licensed under Creative Commons Attribution 4.0 International (CC BY 4.0).
Wiki powered by ghwikipp.