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)