Provided by: allegro4-doc_4.4.2-7_all 

NAME
set_multiply_blender - Enables a multiply blender mode. Allegro game programming library.
SYNOPSIS
#include <allegro.h>
void set_multiply_blender(int r, int g, int b, int a);
DESCRIPTION
Enables a multiply blender mode for combining translucent or lit truecolor pixels. Combines the source
and destination images, multiplying the colours to produce a darker colour. If a colour is multiplied by
white it remains unchanged; when multiplied by black it also becomes black.
SEE ALSO
set_trans_blender(3alleg4), drawing_mode(3alleg4), exalpha(3alleg4)
Allegro version 4.4.2 set_multiply_blender(3alleg4)