Extract a color component from a color in a specified pixel format. allegro game programming library.
#include <allegro.h>
int getr_depth(int color_depth, int c);
int getg_depth(int color_depth, int c);
int getb_depth(int color_depth, int c);
int geta_depth(int color_depth, int c);
Given a color in the format being used by the specified color depth, these functions extract one of the red, green, blue, or alpha components (ranging 0-255). The alpha part is only meaningful for 32-bit pixels. Example:
int r, g, b, color_value, bpp; bpp = bitmap_color_depth(bitmap); color_value = getpixel(bitmap, 100, 100); r = getr_depth(bpp, color_value); g = getg_depth(bpp, color_value); b = getb_depth(bpp, color_value);
getr(3alleg4), getr8(3alleg4), geta32(3alleg4), makecol(3alleg4), set_color_depth(3alleg4), exlights(3alleg4)