DOKK / manpages / debian 11 / allegro4-doc / set_difference_blender.3alleg4.en
set_difference_blender(3alleg4) Allegro manual set_difference_blender(3alleg4)

set_difference_blender - Enables a difference blender mode. Allegro game programming library.

#include <allegro.h>

void set_difference_blender(int r, int g, int b, int a);

Enables a difference blender mode for combining translucent or lit truecolor pixels. This makes an image which has colours calculated by the difference between the source and destination colours.

set_trans_blender(3alleg4), drawing_mode(3alleg4)

version 4.4.3 Allegro