v7 man page for set_invert_blender

set_invert_blender(3alleg4)					  Allegro manual				       set_invert_blender(3alleg4)

NAME

       set_invert_blender - Enables an invert blender mode. Allegro game programming library.

SYNOPSIS

       #include <allegro.h>

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

DESCRIPTION

       Enables	an  invert  blender  mode for combining translucent or lit truecolor pixels. Blends the inverse (or negative) colour of the source
       with the destination.

SEE ALSO

       set_trans_blender(3alleg4), drawing_mode(3alleg4)

Allegro 							   version 4.4.2				       set_invert_blender(3alleg4)