Enables a multiply blender mode. allegro game programming library.
#include <allegro.h>
void set_multiply_blender(int r, int g, int b, int a);
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_trans_blender(3alleg4), drawing_mode(3alleg4), exalpha(3alleg4)