gdk-pixbuf-xlibrgb.c

linux下电话本所依赖的一些图形库

			 7 is 15bpp truecolor, 8 is 16bpp truecolor,
			 9 is 24bpp truecolor.
   0x00 is the speed - 1 is the normal case,
                       2 means faster than normal
   00x0 gets a point for being the system visual
   000x gets a point for being pseudocolor

   A caveat: in the 8bpp modes, being the system visual seems to be
   quite important. Thus, all of the 8bpp modes should be ranked at
   the same speed.
*/

static guint32
xlib_rgb_score_visual (XVisualInfo *visual)
{
  guint32 quality, speed, pseudo, sys;
  static const char* visual_names[] =
  {
    "static gray",
    "grayscale",
    "static color",
    "pseudo color",
    "true color",
    "direct color",
  };
  
  
  quality = 0;
  speed = 1;
  sys = 0;
  if (visual->class == TrueColor ||
      visual->class == DirectColor)
    {
      if (visual->depth == 24)
	{
	  quality = 9;
	  /* Should test for MSB visual here, and set speed if so. */
	}
      else if (visual->depth == 16)
	quality = 8;
      else if (visual->depth == 15)
	quality = 7;
      else if (visual->depth == 8)
	quality = 4;
    }
  else if (visual->class == PseudoColor ||
	   visual->class == StaticColor)
    {
      if (visual->depth == 8)
	quality = 4;
      else if (visual->depth == 4)
	quality = 2;
      else if (visual->depth == 1)
	quality = 1;
    }
  else if (visual->class == StaticGray
#ifdef ENABLE_GRAYSCALE
	   || visual->class == GrayScale
#endif
	   )
    {
      if (visual->depth == 8)
	quality = 4;
      else if (visual->depth == 4)
	quality = 2;
      else if (visual->depth == 1)
	quality = 1;
    }

  if (quality == 0)
    return 0;

  sys = (visual->visualid == image_info->default_visualid->visualid);
  
  pseudo = (visual->class == PseudoColor || visual->class == TrueColor);

  if (xlib_rgb_verbose)
    printf ("Visual 0x%x, type = %s, depth = %d, %ld:%ld:%ld%s; score=%x\n",
	    (int)visual->visualid,
	    visual_names[visual->class],
	    visual->depth,
	    visual->red_mask,
	    visual->green_mask,
	    visual->blue_mask,
	    sys ? " (system)" : "",
	    (quality << 12) | (speed << 8) | (sys << 4) | pseudo);
  
  return (quality << 12) | (speed << 8) | (sys << 4) | pseudo;
}

static void
xlib_rgb_choose_visual (void)
{
  XVisualInfo *visuals;
  XVisualInfo *visual;
  XVisualInfo *best_visual;
  XVisualInfo *final_visual;
  XVisualInfo template;
  int num_visuals;
  guint32 score, best_score;
  int cur_visual = 1;
  int i;
  
  template.screen = image_info->screen_num;
  visuals = XGetVisualInfo(image_info->display, VisualScreenMask,
			   &template, &num_visuals);
  
  best_visual = visuals;
  best_score = xlib_rgb_score_visual (best_visual);

  for (i = cur_visual; i < num_visuals; i++)
    {
      visual = &visuals[i];
      score = xlib_rgb_score_visual  (visual);
      if (score > best_score)
	{
	  best_score = score;
	  best_visual = visual;
	}
    }
  /* make a copy of the visual so that we can free
     the allocated visual list above. */
  final_visual = malloc(sizeof(XVisualInfo));
  memcpy(final_visual, best_visual, sizeof(XVisualInfo));
  image_info->x_visual_info = final_visual;
  XFree(visuals);
  /* set up the shift and the precision for the red, green and blue.
     this only applies to cool visuals like true color and direct color. */
  if (image_info->x_visual_info->class == TrueColor ||
      image_info->x_visual_info->class == DirectColor) {
    image_info->red_shift = xlib_get_shift_from_mask(image_info->x_visual_info->red_mask);
    image_info->red_prec = xlib_get_prec_from_mask(image_info->x_visual_info->red_mask);
    image_info->green_shift = xlib_get_shift_from_mask(image_info->x_visual_info->green_mask);
    image_info->green_prec = xlib_get_prec_from_mask(image_info->x_visual_info->green_mask);
    image_info->blue_shift = xlib_get_shift_from_mask(image_info->x_visual_info->blue_mask);
    image_info->blue_prec = xlib_get_prec_from_mask(image_info->x_visual_info->blue_mask);
  }
}

static void
xlib_rgb_choose_visual_for_xprint (int aDepth)
{
  XVisualInfo *visuals;
  XVisualInfo *visual;
  XVisualInfo *best_visual;
  XVisualInfo *final_visual;
  XVisualInfo template;
  int num_visuals;
  int cur_visual = 1;
  int i;

  XWindowAttributes win_att;
  Status ret_stat;
  Visual      *root_visual;

  ret_stat = XGetWindowAttributes(image_info->display, 
			RootWindow(image_info->display, image_info->screen_num),
			&win_att);
  root_visual = win_att.visual;
  template.screen = image_info->screen_num;
  visuals = XGetVisualInfo(image_info->display, VisualScreenMask,
			   &template, &num_visuals);
 
  best_visual = visuals;
  if (best_visual->visual != root_visual) {
     for (i = cur_visual; i < num_visuals; i++) {
        visual = &visuals[i];
        if (visual->visual == root_visual) {
           best_visual = visual;
           break;
        }
      }
   }
  /* make a copy of the visual so that we can free
     the allocated visual list above. */
  final_visual = malloc(sizeof(XVisualInfo));
  memcpy(final_visual, best_visual, sizeof(XVisualInfo));
  image_info->x_visual_info = final_visual;
  XFree(visuals);
  /* set up the shift and the precision for the red, green and blue.
     this only applies to cool visuals like true color and direct color. */
  if (image_info->x_visual_info->class == TrueColor ||
      image_info->x_visual_info->class == DirectColor) {
    image_info->red_shift = xlib_get_shift_from_mask(image_info->x_visual_info->red_mask);
    image_info->red_prec = xlib_get_prec_from_mask(image_info->x_visual_info->red_mask);
    image_info->green_shift = xlib_get_shift_from_mask(image_info->x_visual_info->green_mask);
    image_info->green_prec = xlib_get_prec_from_mask(image_info->x_visual_info->green_mask);
    image_info->blue_shift = xlib_get_shift_from_mask(image_info->x_visual_info->blue_mask);
    image_info->blue_prec = xlib_get_prec_from_mask(image_info->x_visual_info->blue_mask);
  }
}

static void xlib_rgb_select_conv (XImage *image, ByteOrder byte_order);

static void
xlib_rgb_set_gray_cmap (Colormap cmap)
{
  int i;
  XColor color;
  int status;
  unsigned long pixels[256];
  int r, g, b, gray;

  for (i = 0; i < 256; i++)
    {
      color.pixel = i;
      color.red = i * 257;
      color.green = i * 257;
      color.blue = i * 257;
      status = XAllocColor(image_info->display, cmap, &color);
      pixels[i] = color.pixel;
#ifdef VERBOSE
      printf ("allocating pixel %d, %x %x %x, result %d\n",
	       color.pixel, color.red, color.green, color.blue, status);
#endif
    }

  /* Now, we make fake colorcubes - we ultimately just use the pseudocolor
     methods. */

  colorcube = malloc(sizeof(unsigned char) * 4096);

  for (i = 0; i < 4096; i++)
    {
      r = (i >> 4) & 0xf0;
      r = r | r >> 4;
      g = i & 0xf0;
      g = g | g >> 4;
      b = (i << 4 & 0xf0);
      b = b | b >> 4;
      gray = (g + ((r + b) >> 1)) >> 1;
      colorcube[i] = pixels[gray];
    }
}

/**
 * xlib_rgb_init:
 * @display: X Display to use.
 * @screen: Screen to use.
 * 
 * Initializes the XlibRGB machinery with the default depth.  If you use this
 * function XlibRGB will automatically pick the best visual available on your
 * display.  This function or xlib_rgb_init_with_depth() must be called before
 * using any of the other functions in XlibRGB.
 **/
void
xlib_rgb_init (Display *display, Screen *screen)
{
  int prefDepth = -1;            /*  let the function do the visual scoring */
  xlib_rgb_init_with_depth(display, screen, prefDepth);
}