gdkcc.c

gtk是linux一款强大的夸平台的图形化开发工具

  
  *nallocated = 0;
  
  /* First allocate all pixels */
  
  for (i = 0; i < ncolors; i++)
    {
      /* used[i] is only -1 if the pixel at that location hasn't
       * been allocated yet.  This is a sanity check required for proper
       * color allocation by the progressive image loader.
       * When colors[i] == 0 it indicates the slot is available for
       * allocation.
       */
      
      if (used[i] != FALSE)
	{
	  if (colors[i] == 0)
	    {
	      defs[i].red   = reds[i];
	      defs[i].green = greens[i];
	      defs[i].blue  = blues[i];
	      
	      colors[i] = gdk_color_context_get_pixel (cc, reds[i], greens[i], blues[i], &bad_alloc);
	      
	      /* successfully allocated, store it */
	      
	      if (!bad_alloc)
		{
		  defs[i].pixel = colors[i];
		  allocated[ncols++] = colors[i];
		}
	      else
		failed[nopen++] = i;
	    }
#ifdef DEBUG
	  else
	    GDK_NOTE (COLOR_CONTEXT,
		      g_message ("gdk_color_context_get_pixels_incremental: "
				 "pixel at slot %i already allocated, skipping\n", i));
#endif
	}
    }
  
  *nallocated = ncols;
  
  if ((ncols == ncolors) || (nopen == 0))
    {
      GDK_NOTE (COLOR_CONTEXT,
		g_message ("gdk_color_context_get_pixels_incremental: got all %i colors "
			   "(%i colors allocated so far)\n",
			   ncolors, cc->num_allocated));
      
      return;
    }
  
  cmapsize = MIN (cc->num_colors, MAX_IMAGE_COLORS);
  
  if (cmapsize < 0)
    {
      g_warning ("gdk_color_context_get_pixels_incremental: oops!  "
		 "No colors available images will look *really* ugly.");
      return;
    }
  
#ifdef G_ENABLE_DEBUG
  exact_col = ncols;
#endif
  
  /* initialize pixels */
  
  for (i = 0; i < cmapsize; i++)
    {
      cmap[i].pixel = i;
      cmap[i].red = cmap[i].green = cmap[i].blue = 0;
    }
  
  /* read */
  
  my_x_query_colors (cc->colormap, cmap, cmapsize);
  
  /* now match any unallocated colors */
  
  counter = nopen;
  nopen = 0;
  idx = 0;
  
  do
    {
      gint d, j, mdist, close, ri, gi, bi;
      gint rd, gd, bd;
      
      i = failed[idx];
      
      mdist = 0x1000000;
      close = -1;
      
      /* store */
      
      ri = reds[i];
      gi = greens[i];
      bi = blues[i];
      
      for (j = 0; (j < cmapsize) && (mdist != 0); j++)
	{
	  /* Don't replace these by shifts; the sign may get clobbered */
	  
	  rd = (ri - cmap[j].red) / 256;
	  gd = (gi - cmap[j].green) / 256;
	  bd = (bi - cmap[j].blue) / 256;
	  
	  d = rd * rd + gd * gd + bd * bd;
	  
	  if (d < mdist)
	    {
	      close = j;
	      mdist = d;
	    }
	}
      
      if (close != -1)
	{
	  rd = cmap[close].red;
	  gd = cmap[close].green;
	  bd = cmap[close].blue;
	  
	  /* allocate */
	  
	  colors[i] = gdk_color_context_get_pixel (cc, rd, gd, bd, &bad_alloc);
	  
	  /* store */
	  
	  if (!bad_alloc)
	    {
	      defs[i] = cmap[close];
	      defs[i].pixel = colors[i];
	      allocated[ncols++] = colors[i];
#ifdef G_ENABLE_DEBUG
	      close_col++;
#endif
	    }
	  else
	    failed[nopen++] = i;
	}
      else
	failed[nopen++] = i;
      /* deal with in next stage if allocation failed */
    }
  while (++idx < counter);
  
  *nallocated = ncols;
  
  if ((ncols == ncolors) || (nopen == 0))
    {
      GDK_NOTE (COLOR_CONTEXT,
		g_message ("gdk_color_context_get_pixels_incremental: "
			   "got %i colors, %i exact and %i close "
			   "(%i colors allocated so far)\n",
			   ncolors, exact_col, close_col, cc->num_allocated));
      
      return;
    }
  
  /* map remaining unallocated pixels into colors we did get */
  
  idx = 0;
  
  do
    {
      gint d, mdist, close, ri, gi, bi;
      gint j, rd, gd, bd;
      
      i = failed[idx];
      
      mdist = 0x1000000;
      close = -1;
      
      ri = reds[i];
      gi = greens[i];
      bi = blues[i];
      
      /* search allocated colors */
      
      for (j = 0; (j < ncols) && (mdist != 0); j++)
	{
	  k = allocated[j];
	  
	  /* downscale */
	  /* Don't replace these by shifts; the sign may get clobbered */
	  
	  rd = (ri - defs[k].red) / 256;
	  gd = (gi - defs[k].green) / 256;
	  bd = (bi - defs[k].blue) / 256;
	  
	  d = rd * rd + gd * gd + bd * bd;
	  
	  if (d < mdist)
	    {
	      close = k;
	      mdist = d;
	    }
	}
      
      if (close < 0)
	{
	  /* too bad, map to black */
	  
	  defs[i].pixel = cc->black_pixel;
	  defs[i].red = defs[i].green = defs[i].blue = 0;
#ifdef G_ENABLE_DEBUG
	  black_col++;
#endif
	}
      else
	{
	  defs[i] = defs[close];
#ifdef G_ENABLE_DEBUG
	  subst_col++;
#endif
	}
      
      colors[i] = defs[i].pixel;
    }
  while (++idx < nopen);
  
  GDK_NOTE (COLOR_CONTEXT,
	    g_message ("gdk_color_context_get_pixels_incremental: "
		       "got %i colors, %i exact, %i close, %i substituted, %i to black "
		       "(%i colors allocated so far)\n",
		       ncolors, exact_col, close_col, subst_col, black_col, cc->num_allocated));
}

gint
gdk_color_context_query_color (GdkColorContext *cc,
			       GdkColor        *color)
{
  return gdk_color_context_query_colors (cc, color, 1);
}

gint
gdk_color_context_query_colors (GdkColorContext *cc,
				GdkColor        *colors,
				gint             num_colors)
{
  gint i;
  GdkColor *tc;
  
  g_assert (cc != NULL);
  g_assert (colors != NULL);
  
  switch (cc->mode)
    {
    case GDK_CC_MODE_BW:
      for (i = 0, tc = colors; i < num_colors; i++, tc++)
	{
	  if (tc->pixel == cc->white_pixel)
	    tc->red = tc->green = tc->blue = 65535;
	  else
	    tc->red = tc->green = tc->blue = 0;
	}
      break;
      
    case GDK_CC_MODE_TRUE:
      if (cc->clut == NULL)
	for (i = 0, tc = colors; i < num_colors; i++, tc++)
	  {
	    tc->red   = ((tc->pixel & cc->masks.red) >> cc->shifts.red) << (16 - cc->bits.red);
	    tc->green = ((tc->pixel & cc->masks.green) >> cc->shifts.green) << (16 - cc->bits.green);
	    tc->blue  = ((tc->pixel & cc->masks.blue) >> cc->shifts.blue) << (16 - cc->bits.blue);
	  }
      else
	{
	  my_x_query_colors (cc->colormap, colors, num_colors);
	  return 1;
	}
      break;
      
    case GDK_CC_MODE_STD_CMAP:
    default:
      if (cc->cmap == NULL)
	{
	  my_x_query_colors (cc->colormap, colors, num_colors);
	  return 1;
	}
      else
	{
	  gint first, last, half;
	  gulong half_pixel;
	  
	  for (i = 0, tc = colors; i < num_colors; i++)
	    {
	      first = 0;
	      last = cc->num_colors - 1;
	      
	      while (first <= last)
		{
		  half = (first + last) / 2;
		  half_pixel = cc->cmap[half].pixel;
		  
		  if (tc->pixel == half_pixel)
		    {
		      tc->red   = cc->cmap[half].red;
		      tc->green = cc->cmap[half].green;
		      tc->blue  = cc->cmap[half].blue;
		      first = last + 1; /* false break */
		    }
		  else
		    {
		      if (tc->pixel > half_pixel)
			first = half + 1;
		      else
			last = half - 1;
		    }
		}
	    }
	  return 1;
	}
      break;
    }
  return 1;
}

gint
gdk_color_context_add_palette (GdkColorContext *cc,
			       GdkColor        *palette,
			       gint             num_palette)
{
  gint i, j, erg;
  gushort r, g, b;
  gulong pixel[1];
  
  g_assert (cc != NULL);
  
  /* initialize this palette (will also erase previous palette as well) */
  
  init_palette (cc);
  
  /* restore previous mode if we aren't adding a new palette */
  
  if (num_palette == 0)
    return 0;
  
  /* copy incoming palette */
  
  cc->palette = g_new0(GdkColor, num_palette);
  
  j = 0;
  
  for (i = 0; i < num_palette; i++)
    {
      erg = 0;
      pixel[0] = 0;
      
      /* try to allocate this color */
      
      r = palette[i].red;
      g = palette[i].green;
      b = palette[i].blue;
      
      gdk_color_context_get_pixels (cc, &r, &g, &b, 1, pixel, &erg);
      
      /* only store if we succeed */
      
      if (erg)
	{
	  /* store in palette */
	  
	  cc->palette[j].red   = r;
	  cc->palette[j].green = g;
	  cc->palette[j].blue  = b;
	  cc->palette[j].pixel = pixel[0];
	  
	  /* move to next slot */
	  
	  j++;
	}
    }
  
  /* resize to fit */
  
  if (j != num_palette)
    cc->palette = g_realloc (cc->palette, j * sizeof (GdkColor));
  
  /* clear the hash table, we don't use it when dithering */
  
  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;
    }
  
  /* store real palette size */
  
  cc->num_palette = j;
  
  /* switch to palette mode */
  
  cc->mode = GDK_CC_MODE_PALETTE;
  
  /* sort palette */
  
  qsort (cc->palette, cc->num_palette, sizeof (GdkColor), pixel_sort);
  
  cc->fast_dither = NULL;
  
  return j;
}

void
gdk_color_context_init_dither (GdkColorContext *cc)
{
  gint rr, gg, bb, err, erg, erb;
  gint success = FALSE;
  
  g_assert (cc != NULL);
  
  /* now we can initialize the fast dither matrix */
  
  if (cc->fast_dither == NULL)
    cc->fast_dither = g_new (GdkColorContextDither, 1);
  
  /* Fill it.  We ignore unsuccessful allocations, they are just mapped
   * to black instead */
  
  for (rr = 0; rr < 32; rr++)
    for (gg = 0; gg < 32; gg++)
      for (bb = 0; bb < 32; bb++)
	{
	  err = (rr << 3) | (rr >> 2);
	  erg = (gg << 3) | (gg >> 2);
	  erb = (bb << 3) | (bb >> 2);
	  
	  cc->fast_dither->fast_rgb[rr][gg][bb] =
	    gdk_color_context_get_index_from_palette (cc, &err, &erg, &erb, &success);
	  cc->fast_dither->fast_err[rr][gg][bb] = err;
	  cc->fast_dither->fast_erg[rr][gg][bb] = erg;
	  cc->fast_dither->fast_erb[rr][gg][bb] = erb;
	}
}

void
gdk_color_context_free_dither (GdkColorContext *cc)
{
  g_assert (cc != NULL);
  
  if (cc->fast_dither)
    g_free (cc->fast_dither);
  
  cc->fast_dither = NULL;
}

gulong
gdk_color_context_get_pixel_from_palette (GdkColorContext *cc,
					  gushort         *red,
					  gushort         *green,
					  gushort         *blue,
					  gint            *failed)
{
  gulong pixel = 0;
  gint dif, dr, dg, db, j = -1;
  gint mindif = 0x7fffffff;
  gint err = 0, erg = 0, erb = 0;
  gint i;
  
  g_assert (cc != NULL);
  g_assert (red != NULL);
  g_assert (green != NULL);
  g_assert (blue != NULL);
  g_assert (failed != NULL);
  
  *failed = FALSE;
  
  for (i = 0; i < cc->num_palette; i++)
    {
      dr = *red - cc->palette[i].red;
      dg = *green - cc->palette[i].green;
      db = *blue - cc->palette[i].blue;
      
      dif = dr * dr + dg * dg + db * db;
      
      if (dif < mindif)
	{
	  mindif = dif;
	  j = i;
	  pixel = cc->palette[i].pixel;
	  err = dr;
	  erg = dg;
	  erb = db;
	  
	  if (mindif == 0)
	    break;
	}
    }
  
  /* we failed to map onto a color */
  
  if (j == -1)
    *failed = TRUE;
  else
    {
      *red   = ABS (err);
      *green = ABS (erg);
      *blue  = ABS (erb);
    }
  
  return pixel;
}

guchar
gdk_color_context_get_index_from_palette (GdkColorContext *cc,
					  gint            *red,
					  gint            *green,
					  gint            *blue,
					  gint            *failed)
{
  gint dif, dr, dg, db, j = -1;
  gint mindif = 0x7fffffff;
  gint err = 0, erg = 0, erb = 0;
  gint i;
  
  g_assert (cc != NULL);
  g_assert (red != NULL);
  g_assert (green != NULL);
  g_assert (blue != NULL);
  g_assert (failed != NULL);
  
  *failed = FALSE;
  
  for (i = 0; i < cc->num_palette; i++)
    {
      dr = *red - cc->palette[i].red;
      dg = *green - cc->palette[i].green;
      db = *blue - cc->palette[i].blue;
      
      dif = dr * dr + dg * dg + db * db;
      
      if (dif < mindif)
	{
	  mindif = dif;
	  j = i;
	  err = dr;
	  erg = dg;
	  erb = db;
	  
	  if (mindif == 0)
	    break;
	}
    }
  
  /* we failed to map onto a color */
  
  if (j == -1)
    {
      *failed = TRUE;
      j = 0;
    }
  else
    {
      /* return error fractions */
      
      *red   = err;
      *green = erg;
      *blue  = erb;
    }
  
  return j;
}