gdkcc.c

gtk是linux一款强大的夸平台的图形化开发工具

/* GDK - The GIMP Drawing Kit
 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/* Color Context module
 * Copyright 1994,1995 John L. Cwikla
 * Copyright (C) 1997 by Ripley Software Development
 * Copyright (C) 1997 by Federico Mena (port to Gtk/Gdk)
 */

/* Copyright 1994,1995 John L. Cwikla
 *
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appears in all copies and that
 * both that copyright notice and this permission notice appear in
 * supporting documentation, and that the name of John L. Cwikla or
 * Wolfram Research, Inc not be used in advertising or publicity
 * pertaining to distribution of the software without specific, written
 * prior permission.  John L. Cwikla and Wolfram Research, Inc make no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 * John L. Cwikla and Wolfram Research, Inc disclaim all warranties with
 * regard to this software, including all implied warranties of
 * merchantability and fitness, in no event shall John L. Cwikla or
 * Wolfram Research, Inc be liable for any special, indirect or
 * consequential damages or any damages whatsoever resulting from loss of
 * use, data or profits, whether in an action of contract, negligence or
 * other tortious action, arising out of or in connection with the use or
 * performance of this software.
 *
 * Author:
 *  John L. Cwikla
 *  X Programmer
 *  Wolfram Research Inc.
 *
 *  [e-mail]
 */

/*
 * Modified by the GTK+ Team and others 1997-1999.  See the AUTHORS
 * file for a list of people on the GTK+ Team.  See the ChangeLog
 * files for a list of changes.  These files are distributed with
 * GTK+ at ftp://ftp.gtk.org/pub/gtk/. 
 */

#include <X11/Xlib.h>
#include <stdlib.h>
#include <string.h>
#include "gdk.h"
#include "gdkprivate.h"
#include "gdkx.h"


#define MAX_IMAGE_COLORS 256


static guint
hash_color (gconstpointer key)
{
  const GdkColor *color = key;
  
  return (color->red * 33023 + color->green * 30013 + color->blue * 27011);
}

static gint
compare_colors (gconstpointer a,
		gconstpointer b)
{
  const GdkColor *aa = a;
  const GdkColor *bb = b;
  
  return ((aa->red == bb->red) && (aa->green == bb->green) && (aa->blue == bb->blue));
}

static void
free_hash_entry (gpointer key,
		 gpointer value,
		 gpointer user_data)
{
  g_free (key); /* key and value are the same GdkColor */
}

static int
pixel_sort (const void *a, const void *b)
{
  return ((GdkColor *) a)->pixel - ((GdkColor *) b)->pixel;
}

/* XXX: This function does an XQueryColors() the hard way, because there is
 * no corresponding function in Gdk.
 */

static void
my_x_query_colors (GdkColormap *colormap,
		   GdkColor    *colors,
		   gint         ncolors)
{
  XColor *xcolors;
  gint    i;
  
  xcolors = g_new (XColor, ncolors);
  for (i = 0; i < ncolors; i++)
    xcolors[i].pixel = colors[i].pixel;
  
  XQueryColors (gdk_display, GDK_COLORMAP_XCOLORMAP (colormap), xcolors, ncolors);
  
  for (i = 0; i < ncolors; i++)
    {
      colors[i].red   = xcolors[i].red;
      colors[i].green = xcolors[i].green;
      colors[i].blue  = xcolors[i].blue;
    }
  
  g_free (xcolors);
}

static void
query_colors (GdkColorContext *cc)
{
  gint i;
  GdkColorContextPrivate *ccp = (GdkColorContextPrivate *) cc;
  cc->cmap = g_new (GdkColor, cc->num_colors);
  
  for (i = 0; i < cc->num_colors; i++)
    cc->cmap[i].pixel = cc->clut ? cc->clut[i] : ccp->std_cmap.base_pixel + i;
  
  my_x_query_colors (cc->colormap, cc->cmap, cc->num_colors);
  
  qsort (cc->cmap, cc->num_colors, sizeof (GdkColor), pixel_sort);
}

static void
init_bw (GdkColorContext *cc)
{
  GdkColor color;
  
  g_warning ("init_bw: failed to allocate colors, falling back to black and white");
  
  cc->mode = GDK_CC_MODE_BW;
  
  color.red = color.green = color.blue = 0;
  
  if (!gdk_color_alloc (cc->colormap, &color))
    cc->black_pixel = 0;
  else
    cc->black_pixel = color.pixel;
  
  color.red = color.green = color.blue = 0xffff;
  
  if (!gdk_color_alloc (cc->colormap, &color))
    cc->white_pixel = cc->black_pixel ? 0 : 1;
  else
    cc->white_pixel = color.pixel;
  
  cc->num_colors = 2;
}

static void
init_gray (GdkColorContext *cc)
{
  GdkColorContextPrivate *ccp = (GdkColorContextPrivate *) cc;
  GdkColor *clrs, *cstart;
  gint i;
  gdouble dinc;
  
  cc->num_colors = GDK_VISUAL_XVISUAL (cc->visual)->map_entries;
  
  cc->clut = g_new (gulong, cc->num_colors);
  cstart = g_new (GdkColor, cc->num_colors);
  
 retrygray:
  
  dinc = 65535.0 / (cc->num_colors - 1);
  
  clrs = cstart;
  
  for (i = 0; i < cc->num_colors; i++)
    {
      clrs->red = clrs->green = clrs->blue = dinc * i;
      
      if (!gdk_color_alloc (cc->colormap, clrs))
	{
	  gdk_colors_free (cc->colormap, cc->clut, i, 0);
	  
	  cc->num_colors /= 2;
	  
	  if (cc->num_colors > 1)
	    goto retrygray;
	  else
	    {
	      g_free (cc->clut);
	      cc->clut = NULL;
	      init_bw (cc);
	      g_free (cstart);
	      return;
	    }
	}
      
      cc->clut[i] = clrs++->pixel;
    }
  
  g_free (cstart);
  
  /* XXX: is this the right thing to do? */
  ccp->std_cmap.colormap = GDK_COLORMAP_XCOLORMAP (cc->colormap);
  ccp->std_cmap.base_pixel = 0;
  ccp->std_cmap.red_max = cc->num_colors - 1;
  ccp->std_cmap.green_max = 0;
  ccp->std_cmap.blue_max = 0;
  ccp->std_cmap.red_mult = 1;
  ccp->std_cmap.green_mult = 0;
  ccp->std_cmap.blue_mult = 0;
  
  cc->white_pixel = WhitePixel (ccp->xdisplay, gdk_screen);
  cc->black_pixel = BlackPixel (ccp->xdisplay, gdk_screen);
  
  query_colors (cc);
  
  cc->mode = GDK_CC_MODE_MY_GRAY;
}

static void
init_color (GdkColorContext *cc)
{
  GdkColorContextPrivate *ccp = (GdkColorContextPrivate *) cc;
  gint cubeval;
  
  cubeval = 1;
  while ((cubeval * cubeval * cubeval) < GDK_VISUAL_XVISUAL (cc->visual)->map_entries)
    cubeval++;
  cubeval--;
  
  cc->num_colors = cubeval * cubeval * cubeval;
  
  ccp->std_cmap.red_max    = cubeval - 1;
  ccp->std_cmap.green_max  = cubeval - 1;
  ccp->std_cmap.blue_max   = cubeval - 1;
  ccp->std_cmap.red_mult   = cubeval * cubeval;
  ccp->std_cmap.green_mult = cubeval;
  ccp->std_cmap.blue_mult  = 1;
  ccp->std_cmap.base_pixel = 0;
  
  cc->white_pixel = WhitePixel (ccp->xdisplay, gdk_screen);
  cc->black_pixel = BlackPixel (ccp->xdisplay, gdk_screen);
  cc->num_colors = DisplayCells (ccp->xdisplay, gdk_screen);
  
  /* a CLUT for storing allocated pixel indices */
  
  cc->max_colors = cc->num_colors;
  cc->clut = g_new (gulong, cc->max_colors);
  
  for (cubeval = 0; cubeval < cc->max_colors; cubeval++)
    cc->clut[cubeval] = cubeval;
  
  query_colors (cc);
  
  cc->mode = GDK_CC_MODE_STD_CMAP;
}


static void
init_true_color (GdkColorContext *cc)
{
  GdkColorContextPrivate *ccp = (GdkColorContextPrivate *) cc;
  gulong rmask, gmask, bmask;
  
  cc->mode = GDK_CC_MODE_TRUE;
  
  /* Red */
  
  rmask = cc->masks.red = cc->visual->red_mask;
  
  cc->shifts.red = 0;
  cc->bits.red = 0;
  
  while (!(rmask & 1))
    {
      rmask >>= 1;
      cc->shifts.red++;
    }
  
  while (rmask & 1)
    {
      rmask >>= 1;
      cc->bits.red++;
    }
  
  /* Green */
  
  gmask = cc->masks.green = cc->visual->green_mask;
  
  cc->shifts.green = 0;
  cc->bits.green = 0;
  
  while (!(gmask & 1))
    {
      gmask >>= 1;
      cc->shifts.green++;
    }
  
  while (gmask & 1)
    {
      gmask >>= 1;
      cc->bits.green++;
    }
  
  /* Blue */
  
  bmask = cc->masks.blue = cc->visual->blue_mask;
  
  cc->shifts.blue = 0;
  cc->bits.blue = 0;
  
  while (!(bmask & 1))
    {
      bmask >>= 1;
      cc->shifts.blue++;
    }
  
  while (bmask & 1)
    {
      bmask >>= 1;
      cc->bits.blue++;
    }
  
  cc->num_colors = (cc->visual->red_mask | cc->visual->green_mask | cc->visual->blue_mask) + 1;
  cc->white_pixel = WhitePixel (ccp->xdisplay, gdk_screen);
  cc->black_pixel = BlackPixel (ccp->xdisplay, gdk_screen);
}

static void
init_direct_color (GdkColorContext *cc)
{
  gint n, count;
  GdkColor *clrs, *cstart;
  gulong rval, gval, bval;
  gulong *rtable;
  gulong *gtable;
  gulong *btable;
  gdouble dinc;
  
  init_true_color (cc); /* for shift stuff */
  
  rval = cc->visual->red_mask >> cc->shifts.red;
  gval = cc->visual->green_mask >> cc->shifts.green;
  bval = cc->visual->blue_mask >> cc->shifts.blue;
  
  rtable = g_new (gulong, rval + 1);
  gtable = g_new (gulong, gval + 1);
  btable = g_new (gulong, bval + 1);
  
  cc->max_entry = MAX (rval, gval);
  cc->max_entry = MAX (cc->max_entry, bval);
  
  cstart = g_new (GdkColor, cc->max_entry + 1);
  cc->clut = g_new (gulong, cc->max_entry + 1);
  
 retrydirect:
  
  for (n = 0; n < rval; n++)
    rtable[n] = rval ? (65535.0 / rval * n) : 0;
  
  for (n = 0; n < gval; n++)
    gtable[n] = gval ? (65535.0 / gval * n) : 0;
  
  for (n = 0; n < bval; n++)
    btable[n] = bval ? (65535.0 / bval * n) : 0;
  
  cc->max_entry = MAX (rval, gval);
  cc->max_entry = MAX (cc->max_entry, bval);
  
  count = 0;
  clrs = cstart;
  cc->num_colors = (rval + 1) * (gval + 1) * (bval + 1);
  
  for (n = 0; n < cc->max_entry; n++)
    {
      dinc = (double) n / cc->max_entry;
      
      clrs->red   = rtable[(int) (dinc * rval)];
      clrs->green = gtable[(int) (dinc * gval)];
      clrs->blue  = btable[(int) (dinc * bval)];
      
      if (gdk_color_alloc (cc->colormap, clrs))
	{
	  cc->clut[count++] = clrs->pixel;
	  clrs++;
	}
      else
	{
	  gdk_colors_free (cc->colormap, cc->clut, count, 0);
	  
	  rval >>= 1;
	  gval >>= 1;
	  bval >>= 1;
	  
	  cc->masks.red   = (cc->masks.red >> 1) & cc->visual->red_mask;
	  cc->masks.green = (cc->masks.green >> 1) & cc->visual->green_mask;
	  cc->masks.blue  = (cc->masks.blue >> 1) & cc->visual->blue_mask;
	  
	  cc->shifts.red++;
	  cc->shifts.green++;
	  cc->shifts.blue++;
	  
	  cc->bits.red--;
	  cc->bits.green--;
	  cc->bits.blue--;
	  
	  cc->num_colors = (rval + 1) * (gval + 1) * (bval + 1);
	  
	  if (cc->num_colors >1)
	    goto retrydirect;
	  else
	    {
	      g_free (cc->clut);
	      cc->clut = NULL;
	      init_bw (cc);
	      break;
	    }
	}
    }
  
  /* Update allocated color count; original num_colors is max_entry, which
   * is not necessarily the same as the really allocated number of colors.
   */
  
  cc->num_colors = count;
  
  g_free (rtable);
  g_free (gtable);
  g_free (btable);
  g_free (cstart);
}

static void
init_palette (GdkColorContext *cc)
{
  /* restore correct mode for this cc */
  
  switch (cc->visual->type)
    {
    case GDK_VISUAL_STATIC_GRAY:
    case GDK_VISUAL_GRAYSCALE:
      if (GDK_VISUAL_XVISUAL (cc->visual)->map_entries == 2)
	cc->mode = GDK_CC_MODE_BW;
      else
	cc->mode = GDK_CC_MODE_MY_GRAY;
      break;
      
    case GDK_VISUAL_TRUE_COLOR:
    case GDK_VISUAL_DIRECT_COLOR:
      cc->mode = GDK_CC_MODE_TRUE;
      break;
      
    case GDK_VISUAL_STATIC_COLOR:
    case GDK_VISUAL_PSEUDO_COLOR:
      cc->mode = GDK_CC_MODE_STD_CMAP;
      break;
      
    default:
      cc->mode = GDK_CC_MODE_UNDEFINED;
      break;
    }
  
  /* previous palette */
  
  if (cc->num_palette)
    g_free (cc->palette);
  
  if (cc->fast_dither)
    g_free (cc->fast_dither);
  
  /* clear hash table if present */
  
  if (cc->color_hash)
    {
      g_hash_table_foreach (cc->color_hash,
			    free_hash_entry,
			    NULL);
      g_hash_table_destroy (cc->color_hash);
      cc->color_hash = NULL;
    }
  
  cc->palette = NULL;
  cc->num_palette = 0;
  cc->fast_dither = NULL;
}

GdkColorContext *
gdk_color_context_new (GdkVisual   *visual,
		       GdkColormap *colormap)
{
  GdkColorContextPrivate *ccp;
  gint use_private_colormap = FALSE; /* XXX: maybe restore full functionality later? */
  GdkColorContext *cc;
  gint retry_count;
  GdkColormap *default_colormap;
  
  g_assert (visual != NULL);
  g_assert (colormap != NULL);
  
  ccp = g_new (GdkColorContextPrivate, 1);
  cc = (GdkColorContext *) ccp;
  ccp->xdisplay = gdk_display;
  cc->visual = visual;
  cc->colormap = colormap;
  cc->clut = NULL;
  cc->cmap = NULL;
  cc->mode = GDK_CC_MODE_UNDEFINED;
  cc->need_to_free_colormap = FALSE;
  
  cc->color_hash = NULL;
  cc->palette = NULL;
  cc->num_palette = 0;
  cc->fast_dither = NULL;
  
  default_colormap = gdk_colormap_get_system ();
  
  retry_count = 0;
  
  while (retry_count < 2)
    {
      /* Only create a private colormap if the visual found isn't equal
       * to the default visual and we don't have a private colormap,
       * -or- if we are instructed to create a private colormap (which
       * never is the case for XmHTML).
       */
      
      if (use_private_colormap
	  || ((cc->visual != gdk_visual_get_system ()) /* default visual? */
	      && (GDK_COLORMAP_XCOLORMAP (colormap) == GDK_COLORMAP_XCOLORMAP (default_colormap))))
	{
	  g_warning ("gdk_color_context_new: non-default visual detected, "
		     "using private colormap");
	  
	  cc->colormap = gdk_colormap_new (cc->visual, FALSE);
	  
	  cc->need_to_free_colormap = (GDK_COLORMAP_XCOLORMAP (colormap)
				       != GDK_COLORMAP_XCOLORMAP (default_colormap));
	}
      
      switch (visual->type)
	{
	case GDK_VISUAL_STATIC_GRAY:
	case GDK_VISUAL_GRAYSCALE:
	  GDK_NOTE (COLOR_CONTEXT,
		    g_message ("gdk_color_context_new: visual class is %s\n",
			       (visual->type == GDK_VISUAL_STATIC_GRAY) ?
			       "GDK_VISUAL_STATIC_GRAY" :
			       "GDK_VISUAL_GRAYSCALE"));
	  
	  if (GDK_VISUAL_XVISUAL (cc->visual)->map_entries == 2)
	    init_bw (cc);
	  else
	    init_gray (cc);