set_multiply_blender - Enables a multiply blender mode. Allegro game programming library.

       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.

       set_multiply_blender - Enables a multiply blender mode. Allegro game programming library.

set_trans_blender(3alleg4), drawing_mode(3alleg4), exalpha(3alleg4)

Allegro                                           version 4.4.3                    set_multiply_blender(3alleg4)

#include<allegro.h>voidset_multiply_blender(intr,intg,intb,inta);