ryudo/color.c

/* Copyright (c) 2004 Russ Cox, see README for licence details */
#include <stdio.h>
#include <signal.h>
#include <X11/X.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include "dat.h"
#include "fns.h"

unsigned long colorpixel(
  Display* dpy, ScreenInfo* s, int depth, unsigned long rgb,
  unsigned long def) {
  int r, g, b;

  r = rgb >> 16;
  g = (rgb >> 8) & 0xFF;
  b = rgb & 0xFF;

  switch (depth) {
    case 1:
    case 2:
    case 4:
    case 8:
    default:
      /* not going to waste color map entries */
      return def;
    case 15:
      r >>= 3;
      g >>= 3;
      b >>= 3;
      return (r << 10) | (g << 5) | b;
    case 16:
      r >>= 3;
      g >>= 2;
      b >>= 3;
      return (r << 11) | (g << 5) | b;
    case 24:
    case 32:
      /* try to find byte order */
      if (s->vis->red_mask & 0xff)
        return (r) | (g << 8) | (b << 16); /* OK on Sun */
      return rgb;
  }
}