suse man page for set_multiply_blender

set_multiply_blender(3alleg4)                                     Allegro manual                                     set_multiply_blender(3alleg4)

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)