/* 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.
 */

/*
 * 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 "config.h"

#include "gdkvisual.h"
#include "gdkprivate-win32.h"

static void  gdk_visual_decompose_mask (gulong     mask,
					gint      *shift,
					gint      *prec);

static GdkVisualPrivate *system_visual;

static gint available_depths[1];

static GdkVisualType available_types[1];

#ifdef G_ENABLE_DEBUG

static const gchar* visual_names[] =
{
  "static gray",
  "grayscale",
  "static color",
  "pseudo color",
  "true color",
  "direct color",
};

#endif /* G_ENABLE_DEBUG */

void
gdk_visual_init (void)
{
  struct
  {
    BITMAPINFOHEADER bi;
    union
    {
      RGBQUAD colors[256];
      DWORD fields[256];
    } u;
  } bmi;
  HBITMAP hbm;

  int rastercaps, numcolors, sizepalette, bitspixel;

  system_visual = g_new (GdkVisualPrivate, 1);

  bitspixel = GetDeviceCaps (gdk_DC, BITSPIXEL);
  rastercaps = GetDeviceCaps (gdk_DC, RASTERCAPS);
  system_visual->xvisual = g_new (Visual, 1);
  system_visual->xvisual->visualid = 0;
  system_visual->xvisual->bitspixel = bitspixel;

  if (rastercaps & RC_PALETTE)
    {
      system_visual->visual.type = GDK_VISUAL_PSEUDO_COLOR;
      numcolors = GetDeviceCaps (gdk_DC, NUMCOLORS);
      sizepalette = GetDeviceCaps (gdk_DC, SIZEPALETTE);
      system_visual->xvisual->map_entries = sizepalette;
    }
  else if (bitspixel == 1)
    {
      system_visual->visual.type = GDK_VISUAL_STATIC_GRAY;
      system_visual->xvisual->map_entries = 2;
    }
  else if (bitspixel == 4)
    {
      system_visual->visual.type = GDK_VISUAL_STATIC_COLOR;
      system_visual->xvisual->map_entries = 16;
    }
  else if (bitspixel == 8)
    {
      system_visual->visual.type = GDK_VISUAL_STATIC_COLOR;
      system_visual->xvisual->map_entries = 256;
    }
  else if (bitspixel == 16)
    {
      system_visual->visual.type = GDK_VISUAL_TRUE_COLOR;
#if 1
      /* This code by Mike Enright,
       * see http://www.users.cts.com/sd/m/menright/display.html
       */
      memset (&bmi, 0, sizeof (bmi));
      bmi.bi.biSize = sizeof (bmi.bi);

      hbm = CreateCompatibleBitmap (gdk_DC, 1, 1);
      GetDIBits (gdk_DC, hbm, 0, 1, NULL,
		 (BITMAPINFO *) &bmi, DIB_RGB_COLORS);
      GetDIBits (gdk_DC, hbm, 0, 1, NULL,
		 (BITMAPINFO *) &bmi, DIB_RGB_COLORS);
      DeleteObject (hbm);

      if (bmi.bi.biCompression != BI_BITFIELDS)
	{
	  /* Either BI_RGB or BI_RLE_something
	   * .... or perhaps (!!) something else.
	   * Theoretically biCompression might be
	   * mmioFourCC('c','v','i','d') but I doubt it.
	   */
	  if (bmi.bi.biCompression == BI_RGB)
	    {
	      /* It's 555 */
	      bitspixel = 15;
	      system_visual->visual.red_mask   = 0x00007C00;
	      system_visual->visual.green_mask = 0x000003E0;
	      system_visual->visual.blue_mask  = 0x0000001F;
	    }
	  else
	    {
	      g_assert_not_reached ();
	    }
	}
      else
	{
	  DWORD allmasks =
	    bmi.u.fields[0] | bmi.u.fields[1] | bmi.u.fields[2];
	  int k = 0;
	  while (allmasks)
	    {
	      if (allmasks&1)
		k++;
	      allmasks/=2;
	    }
	  bitspixel = k;
	  system_visual->visual.red_mask = bmi.u.fields[0];
	  system_visual->visual.green_mask = bmi.u.fields[1];
	  system_visual->visual.blue_mask  = bmi.u.fields[2];
	}
#else
      /* Old, incorrect (but still working) code. */
#if 0
      system_visual->visual.red_mask   = 0x0000F800;
      system_visual->visual.green_mask = 0x000007E0;
      system_visual->visual.blue_mask  = 0x0000001F;
#else
      system_visual->visual.red_mask   = 0x00007C00;
      system_visual->visual.green_mask = 0x000003E0;
      system_visual->visual.blue_mask  = 0x0000001F;
#endif
#endif
    }
  else if (bitspixel == 24 || bitspixel == 32)
    {
      bitspixel = 24;
      system_visual->visual.type = GDK_VISUAL_TRUE_COLOR;
      system_visual->visual.red_mask   = 0x00FF0000;
      system_visual->visual.green_mask = 0x0000FF00;
      system_visual->visual.blue_mask  = 0x000000FF;
    }
  else
    g_error ("gdk_visual_init: unsupported BITSPIXEL: %d\n", bitspixel);

  system_visual->visual.depth = bitspixel;
  system_visual->visual.byte_order = GDK_LSB_FIRST;
  system_visual->visual.bits_per_rgb = 42; /* Not used? */

  if ((system_visual->visual.type == GDK_VISUAL_TRUE_COLOR) ||
      (system_visual->visual.type == GDK_VISUAL_DIRECT_COLOR))
    {
      gdk_visual_decompose_mask (system_visual->visual.red_mask,
				 &system_visual->visual.red_shift,
				 &system_visual->visual.red_prec);

      gdk_visual_decompose_mask (system_visual->visual.green_mask,
				 &system_visual->visual.green_shift,
				 &system_visual->visual.green_prec);

      gdk_visual_decompose_mask (system_visual->visual.blue_mask,
				 &system_visual->visual.blue_shift,
				 &system_visual->visual.blue_prec);
      system_visual->xvisual->map_entries =
	1 << (MAX (system_visual->visual.red_prec,
		   MAX (system_visual->visual.green_prec,
			system_visual->visual.blue_prec)));
    }
  else
    {
      system_visual->visual.red_mask = 0;
      system_visual->visual.red_shift = 0;
      system_visual->visual.red_prec = 0;

      system_visual->visual.green_mask = 0;
      system_visual->visual.green_shift = 0;
      system_visual->visual.green_prec = 0;

      system_visual->visual.blue_mask = 0;
      system_visual->visual.blue_shift = 0;
      system_visual->visual.blue_prec = 0;
    }
  system_visual->visual.colormap_size = system_visual->xvisual->map_entries;

  available_depths[0] = system_visual->visual.depth;
  available_types[0] = system_visual->visual.type;
}

GdkVisual*
gdk_visual_ref (GdkVisual *visual)
{
  return visual;
}

void
gdk_visual_unref (GdkVisual *visual)
{
  return;
}

gint
gdk_visual_get_best_depth (void)
{
  return available_depths[0];
}

GdkVisualType
gdk_visual_get_best_type (void)
{
  return available_types[0];
}

GdkVisual*
gdk_visual_get_system (void)
{
  return ((GdkVisual*) system_visual);
}

GdkVisual*
gdk_visual_get_best (void)
{
  return ((GdkVisual*) system_visual);
}

GdkVisual*
gdk_visual_get_best_with_depth (gint depth)
{
  if (depth == system_visual->visual.depth)
    return (GdkVisual*) system_visual;
  else
    return NULL;
}

GdkVisual*
gdk_visual_get_best_with_type (GdkVisualType visual_type)
{
  if (visual_type == system_visual->visual.type)
    return (GdkVisual*) system_visual;
  else
    return NULL;
}

GdkVisual*
gdk_visual_get_best_with_both (gint          depth,
			       GdkVisualType visual_type)
{
  if ((depth == system_visual->visual.depth) &&
      (visual_type == system_visual->visual.type))
    return (GdkVisual*) system_visual;
  else
    return NULL;
}

void
gdk_query_depths  (gint **depths,
		   gint  *count)
{
  *count = 1;
  *depths = available_depths;
}

void
gdk_query_visual_types (GdkVisualType **visual_types,
			gint           *count)
{
  *count = 1;
  *visual_types = available_types;
}

GList*
gdk_list_visuals (void)
{
  return g_list_append (NULL, (gpointer) system_visual);
}

GdkVisual*
gdk_visual_lookup (Visual *xvisual)
{
  if (system_visual->xvisual == xvisual)
    return (GdkVisual *) system_visual;
  else
    return NULL;
}

static void
gdk_visual_decompose_mask (gulong  mask,
			   gint   *shift,
			   gint   *prec)
{
  *shift = 0;
  *prec = 0;

  while (!(mask & 0x1))
    {
      (*shift)++;
      mask >>= 1;
    }

  while (mask & 0x1)
    {
      (*prec)++;
      mask >>= 1;
    }
}