set_burn_blender - Enables a burn blender mode. Allegro game
programming library.
#include <allegro.h>
void set_burn_blender(int r, int g, int b, int a);
Enables a burn blender mode for combining translucent or lit truecolor
pixels. Here the lightness values of the colours of the source image
reduce the lightness of the destination image, darkening the image.
set_trans_blender(3alleg), drawing_mode(3alleg)