man set_add_blender () - Enables an additive blender mode. Allegro game programming library.
NAME
set_add_blender - Enables an additive blender mode. Allegro game programming library.
SYNOPSIS
#include <allegro.h>
void set_add_blender(int r, int g, int b, int a);
DESCRIPTION
Enables an additive blender mode for combining translucent or lit truecolor pixels.