is_inside_bitmap(3alleg4) [opendarwin man page]

is_inside_bitmap(3alleg4)					  Allegro manual					 is_inside_bitmap(3alleg4)

NAME

       is_inside_bitmap - Tells if a point is inside a bitmap. Allegro game programming library.

SYNOPSIS

       #include <allegro.h>

       int is_inside_bitmap(BITMAP *bmp, int x, int y, int clip);

DESCRIPTION

       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.

SEE ALSO

       set_clip_rect(3alleg4), set_clip_state(3alleg4), getpixel(3alleg4)

Allegro 							   version 4.4.2					 is_inside_bitmap(3alleg4)

getpixel(3alleg4)                                                 Allegro manual                                                 getpixel(3alleg4)

NAME

       getpixel - Reads a pixel from a bitmap. Allegro game programming library.

SYNOPSIS

       #include <allegro.h>

       int getpixel(BITMAP *bmp, int x, int y);

DESCRIPTION

       Reads a pixel from point (x, y) in the bitmap.

RETURN VALUE

       Returns  -1 if the point lies outside the bitmap (ignoring the clipping rectangle), otherwise the value of the pixel in the color format of
       the bitmap.

       Warning: -1 is also a valid value for pixels contained in 32-bit bitmaps with alpha channel (when R,G,B,A are all  equal  to  255)  so  you
       can't use the test against -1 as a predicate for such bitmaps. In this cases, the only reliable predicate is is_inside_bitmap().

       To extract the individual color components, use the getr() / getg() / getb() / geta() family of functions.

SEE ALSO

       putpixel(3alleg4),    _getpixel(3alleg4),    is_inside_bitmap(3alleg4),   getr(3alleg4),   getg(3alleg4),   getb(3alleg4),   geta(3alleg4),
       ex12bit(3alleg4), exalpha(3alleg4), exflame(3alleg4), exlights(3alleg4)

Allegro                                                            version 4.4.2                                                 getpixel(3alleg4)