man add_clip_rect () - Expands a bitmap's clipping rectangle with a new area. Allegro game programming library.
NAME
add_clip_rect - Expands a bitmap's clipping rectangle with a new area. Allegro game programming library.
SYNOPSIS
#include <allegro.h>
void add_clip_rect(BITMAP *bitmap, int x1, int y1, int x2, int y2);
DESCRIPTION
Sets the clipping rectangle of the specified bitmap as the intersection of its current clipping rectangle and the rectangle described by the four coordinates.