mojave man page for bitmap_mask_color

bitmap_mask_color(3alleg4)					  Allegro manual					bitmap_mask_color(3alleg4)

NAME
       bitmap_mask_color - Returns the mask color of the specified bitmap. Allegro game programming library.

SYNOPSIS
       #include <allegro.h>

       int bitmap_mask_color(BITMAP *bmp);

DESCRIPTION
       Returns	the mask color for the specified bitmap (the value which is skipped when drawing sprites). For 256-color bitmaps this is zero, and
       for truecolor bitmaps it is bright pink (maximum red and blue, zero green). A frequent use of this function is to clear a bitmap  with  the
       mask color so you can later use this bitmap with masked_blit() or draw_sprite() after drawing other stuff on it. Example:

	  /* Replace mask color with another color. */
	  for (y = 0; y h; y++)
	     for (x = 0; x w; x++)
		if (getpixel(bmp, x, y) == bitmap_mask_color(bmp))
		   putpixel(bmp, x, y, another_color);

SEE ALSO
       MASK_COLOR_8(3alleg4), set_color_depth(3alleg4), bitmap_color_depth(3alleg4), ex3d(3alleg4), exmouse(3alleg4), expat(3alleg4)

Allegro 							   version 4.4.2					bitmap_mask_color(3alleg4)