gdk-pixbuf-xlibrgb.c

linux下电话本所依赖的一些图形库

/* this is the colorcube suitable for dithering */
static void
xlib_rgb_make_colorcube_d (unsigned long *pixels, int nr, int ng, int nb)
{
  int r, g, b;
  int i;

  colorcube_d = malloc(sizeof(unsigned char) * 512);
  memset(colorcube_d, 0, (sizeof(unsigned char) * 512));
  for (i = 0; i < 512; i++)
    {
      r = MIN (nr - 1, i >> 6);
      g = MIN (ng - 1, (i >> 3) & 7);
      b = MIN (nb - 1, i & 7);
      colorcube_d[i] = pixels[(r * ng + g) * nb + b];
    }
}

/* Try installing a color cube of the specified size.
   Make the colorcube and return TRUE on success */
static int
xlib_rgb_try_colormap (int nr, int ng, int nb)
{
  int r, g, b;
  int ri, gi, bi;
  int r0, g0, b0;
  Colormap     cmap;
  XVisualInfo *visual;
  XColor      *colors = NULL;
  XColor       color;
  unsigned long pixels[256];
  unsigned long junk[256];
  int i;
  int d2;
  unsigned int colors_needed;
  int idx;
  int best[256];

  if (nr * ng * nb < xlib_rgb_min_colors)
    return FALSE;

  if (image_info->cmap_alloced) {
    cmap = image_info->cmap;
    visual = image_info->x_visual_info;
  }
  else {
    cmap = image_info->default_colormap;
    visual = image_info->x_visual_info;
  }
  colors_needed = nr * ng * nb;
  for (i = 0; i < 256; i++)
    {
      best[i] = 192;
      pixels[i] = 256;
    }

#ifndef GAMMA
  if (!xlib_rgb_install_cmap) {
    /* go out and get the colors for this colormap. */
    colors = malloc(sizeof(XColor) * visual->colormap_size);
    for (i=0; i < visual->colormap_size; i++){
      colors[i].pixel = i;
    }
    XQueryColors (image_info->display,
		  cmap,
		  colors, visual->colormap_size);
    /* find color cube colors that are already present */
    for (i = 0; i < MIN (256, visual->colormap_size); i++)
      {
	r = colors[i].red >> 8;
	g = colors[i].green >> 8;
	b = colors[i].blue >> 8;
	ri = (r * (nr - 1) + 128) >> 8;
	gi = (g * (ng - 1) + 128) >> 8;
	bi = (b * (nb - 1) + 128) >> 8;
	r0 = ri * 255 / (nr - 1);
	g0 = gi * 255 / (ng - 1);
	b0 = bi * 255 / (nb - 1);
	idx = ((ri * nr) + gi) * nb + bi;
	d2 = (r - r0) * (r - r0) + (g - g0) * (g - g0) + (b - b0) * (b - b0);
	if (d2 < best[idx]) {
	  if (pixels[idx] < 256)
	    XFreeColors(image_info->display,
			cmap,
			pixels + idx,
			1, 0);
	  else
	    colors_needed--;
	  color.pixel = colors[i].pixel;
	  color.red = colors[i].red;
	  color.green = colors[i].green;
	  color.blue = colors[i].blue;
	  color.flags = 0;
	  if (!XAllocColor(image_info->display, cmap, &color))
	    return xlib_rgb_cmap_fail ("error allocating system color\n",
				      cmap, pixels);
	  pixels[idx] = color.pixel; /* which is almost certainly i */
	  best[idx] = d2;
	}
      }
  }

#endif

  if (colors_needed)
    {
      if (!XAllocColorCells(image_info->display, cmap, 0, NULL, 0, junk, colors_needed))
	{
	  char tmp_str[80];
	  
	  sprintf (tmp_str,
		   "%d %d %d colormap failed (in XAllocColorCells)\n",
		   nr, ng, nb);
	  return xlib_rgb_cmap_fail (tmp_str, cmap, pixels);
	}
      XFreeColors(image_info->display, cmap, junk, (int)colors_needed, 0);
    }

  for (r = 0, i = 0; r < nr; r++)
    for (g = 0; g < ng; g++)
      for (b = 0; b < nb; b++, i++)
	{
	  if (pixels[i] == 256)
	    {
	      color.red = r * 65535 / (nr - 1);
	      color.green = g * 65535 / (ng - 1);
	      color.blue = b * 65535 / (nb - 1);

#ifdef GAMMA
	      color.red = 65535 * pow (color.red / 65535.0, 0.5);
	      color.green = 65535 * pow (color.green / 65535.0, 0.5);
	      color.blue = 65535 * pow (color.blue / 65535.0, 0.5);
#endif

	      /* This should be a raw XAllocColor call */
	      if (!XAllocColor(image_info->display, cmap, &color))
		{
		  char tmp_str[80];

		  sprintf (tmp_str, "%d %d %d colormap failed\n",
			   nr, ng, nb);
		  return xlib_rgb_cmap_fail (tmp_str,
					    cmap, pixels);
		}
	      pixels[i] = color.pixel;
	    }
#ifdef VERBOSE
	  printf ("%d: %lx\n", i, pixels[i]);
#endif
	}

  image_info->nred_shades = nr;
  image_info->ngreen_shades = ng;
  image_info->nblue_shades = nb;
  xlib_rgb_make_colorcube (pixels, nr, ng, nb);
  xlib_rgb_make_colorcube_d (pixels, nr, ng, nb);
  if (colors)
    free(colors);
  return TRUE;
}

/* Return TRUE on success. */
static Bool
xlib_rgb_do_colormaps (void)
{
  static const int sizes[][3] = {
    /*    { 6, 7, 6 }, */
    { 6, 6, 6 }, 
    { 6, 6, 5 }, 
    { 6, 6, 4 }, 
    { 5, 5, 5 }, 
    { 5, 5, 4 }, 
    { 4, 4, 4 }, 
    { 4, 4, 3 }, 
    { 3, 3, 3 }, 
    { 2, 2, 2 }
  };
  static const int n_sizes = sizeof(sizes) / (3 * sizeof(int));
  int i;
  
  for (i = 0; i < n_sizes; i++)
    if (xlib_rgb_try_colormap (sizes[i][0], sizes[i][1], sizes[i][2]))
      return TRUE;
  return FALSE;
}

/* Make a 2 x 2 x 2 colorcube */
static void
xlib_rgb_colorcube_222 (void)
{
  int i;
  XColor color;
  Colormap cmap;

  if (image_info->cmap_alloced)
    cmap = image_info->cmap;
  else
    cmap = image_info->default_colormap;

  colorcube_d = malloc(sizeof(unsigned char) * 512);

  for (i = 0; i < 8; i++)
    {
      color.red = ((i & 4) >> 2) * 65535;
      color.green = ((i & 2) >> 1) * 65535;
      color.blue = (i & 1) * 65535;
      XAllocColor (image_info->display, cmap, &color);
      colorcube_d[((i & 4) << 4) | ((i & 2) << 2) | (i & 1)] = color.pixel;
    }
}

/**
 * xlib_rgb_set_verbose:
 * @verbose: %True to be verbose
 * 
 * Enables/disables debug spew.
 **/
void
xlib_rgb_set_verbose (Bool verbose)
{
  xlib_rgb_verbose = verbose;
}

/**
 * xlib_rgb_set_install:
 * @install: %True to install a colormap
 * 
 * Sets whether we install an RGB colormap.
 **/
void
xlib_rgb_set_install (Bool install)
{
  xlib_rgb_install_cmap = install;
}

/**
 * xlib_rgb_set_min_colors:
 * @min_colors: minimum colors to use
 * 
 * Sets the minimum number of colors in the color cube.
 **/
void
xlib_rgb_set_min_colors (int min_colors)
{
  xlib_rgb_min_colors = min_colors;
}

/* Return a "score" based on the following criteria (in hex):

   x000 is the quality - 1 is 1bpp, 2 is 4bpp,
                         4 is 8bpp,