Tells if a point is inside a bitmap. allegro game programming library.
#include <allegro.h>
int is_inside_bitmap(BITMAP *bmp, int x, int y, int clip);
Returns non-zero if point (x, y) lies inside the bitmap. If `clip' is non-zero, the function compares the coordinates with the clipping rectangle, that is it returns non-zero if the point lies inside the clipping rectangle or if clipping is disabled for the bitmap. If `clip' is zero, the function compares the coordinates with the actual dimensions of the bitmap.
set_clip_rect(3alleg4), set_clip_state(3alleg4), getpixel(3alleg4)