gtk/gdk/win32/gdkregion.c

/* 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 <gdk/gdk.h>
#include "gdkprivate.h"


GdkRegion*
gdk_region_new (void)
{
  GdkRegionPrivate *private;
  GdkRegion *region;
  HRGN xregion;
  RECT emptyRect;

  /* Create an empty region */
  SetRectEmpty (&emptyRect);
  xregion = CreateRectRgnIndirect (&emptyRect);
  private = g_new (GdkRegionPrivate, 1);
  private->xregion = xregion;
  region = (GdkRegion*) private;
  region->user_data = NULL;

  return region;
}

void
gdk_region_destroy (GdkRegion *region)
{
  GdkRegionPrivate *private;

  g_return_if_fail (region != NULL);

  private = (GdkRegionPrivate *) region;
  DeleteObject (private->xregion);
  g_free (private);
}

gboolean
gdk_region_empty (GdkRegion      *region)
{
  GdkRegionPrivate *private;
  RECT rect;

  g_return_val_if_fail (region != NULL, 0);

  private = (GdkRegionPrivate *) region;
  
  return (GetRgnBox (private->xregion, &rect) == NULLREGION);
}

gboolean
gdk_region_equal (GdkRegion      *region1,
                  GdkRegion      *region2)
{
  GdkRegionPrivate *private1;
  GdkRegionPrivate *private2;

  g_return_val_if_fail (region1 != NULL, 0);
  g_return_val_if_fail (region2 != NULL, 0);

  private1 = (GdkRegionPrivate *) region1;
  private2 = (GdkRegionPrivate *) region2;
  
  return EqualRgn (private1->xregion, private2->xregion);
}

void
gdk_region_get_clipbox(GdkRegion    *region,
		       GdkRectangle *rectangle)
{
  GdkRegionPrivate *rp;
  RECT r;
  
  g_return_if_fail(region != NULL);
  g_return_if_fail(rectangle != NULL);

  rp = (GdkRegionPrivate *)region;
    
  GetRgnBox (rp->xregion, &r);
  rectangle->x = r.left;
  rectangle->y = r.top;
  rectangle->width = r.right - r.left;
  rectangle->height = r.bottom - r.top;
}

gboolean
gdk_region_point_in (GdkRegion      *region,
                     gint           x,
		     gint           y)
{
  GdkRegionPrivate *private;

  g_return_val_if_fail (region != NULL, 0);

  private = (GdkRegionPrivate *) region;
  
  return PtInRegion (private->xregion, x, y);
}

GdkOverlapType
gdk_region_rect_in (GdkRegion      *region,
                    GdkRectangle   *rect)
{
  GdkRegionPrivate *private;
  RECT r;
  int res;

  g_return_val_if_fail (region != NULL, 0);

  private = (GdkRegionPrivate *) region;
  
  r.left = rect->x;
  r.top = rect->y;
  r.right = rect->x + rect->width;
  r.bottom = rect->y + rect->height;
  
  if (RectInRegion (private->xregion, &r))
    return GDK_OVERLAP_RECTANGLE_PART;

  return GDK_OVERLAP_RECTANGLE_OUT;  /*what else ? */
}
				    
GdkRegion *
gdk_region_polygon (GdkPoint    *points,
		    gint         npoints,
		    GdkFillRule  fill_rule)
{
  GdkRegionPrivate *private;
  GdkRegion *region;
  HRGN xregion;
  POINT *pts;
  gint xfill_rule = ALTERNATE;
  gint i;

  g_return_val_if_fail (points != NULL, NULL);
  g_return_val_if_fail (npoints != 0, NULL); /* maybe we should check for at least three points */

  switch (fill_rule)
    {
    case GDK_EVEN_ODD_RULE:
      xfill_rule = ALTERNATE;
      break;

    case GDK_WINDING_RULE:
      xfill_rule = WINDING;
      break;
    }

  pts = g_malloc (npoints * sizeof (*pts));
  for (i = 0; i < npoints; i++)
    {
      pts[i].x = points[i].x;
      pts[i].y = points[i].y;
    }
  xregion = CreatePolygonRgn (pts, npoints, xfill_rule);
  g_free (pts);

  private = g_new (GdkRegionPrivate, 1);
  private->xregion = xregion;
  region = (GdkRegion *) private;
  region->user_data = NULL;

  return region;
}

void          
gdk_region_offset (GdkRegion      *region,
                   gint           dx,
		   gint           dy)
{
  GdkRegionPrivate *private;

  g_return_if_fail (region != NULL);

  private = (GdkRegionPrivate *) region;
  
  OffsetRgn (private->xregion, dx, dy);
}

void
gdk_region_shrink (GdkRegion      *region,
                   gint           dx,
		   gint           dy)
{
  GdkRegionPrivate *private;
  HRGN shrunken_bbox;
  RECT r;

  g_return_if_fail (region != NULL);

  private = (GdkRegionPrivate *) region;
  
  if (dx > 0 || dy > 0)
    {
      /* We want to shrink it in one or both dimensions.
       * Is it correct just to intersect it with a smaller bounding box?
       * XXX
       */
      GetRgnBox (private->xregion, &r);
      if (dx > 0)
	{
	  r.left += dx - dx/2;
	  r.right -= dx/2;
	}
      if (dy > 0)
	{
	  r.top += dy - dy/2;
	  r.bottom -= dy/2;
	}

      shrunken_bbox = CreateRectRgnIndirect (&r);
      CombineRgn (private->xregion, private->xregion,
		  shrunken_bbox, RGN_AND);
      DeleteObject (shrunken_bbox);
    }
  else
    {
      /* Do nothing if the regions is expanded? XXX */
    }
}

GdkRegion*    
gdk_region_union_with_rect (GdkRegion      *region,
                            GdkRectangle   *rect)
{
  GdkRegionPrivate *private;
  GdkRegion *res;
  GdkRegionPrivate *res_private;
  RECT xrect;
  HRGN rectangle;

  g_return_val_if_fail (region != NULL, NULL);

  private = (GdkRegionPrivate *) region;
  
  xrect.left = rect->x;
  xrect.top = rect->y;
  xrect.right = rect->x + rect->width;
  xrect.bottom = rect->y + rect->height;

  res = gdk_region_new ();
  res_private = (GdkRegionPrivate *) res;
  
  rectangle = CreateRectRgnIndirect (&xrect);
  CombineRgn (res_private->xregion, private->xregion,
	      rectangle, RGN_OR);
  DeleteObject (rectangle);
  return res;
}

GdkRegion*    
gdk_regions_intersect (GdkRegion      *source1,
                       GdkRegion      *source2)
{
  GdkRegionPrivate *private1;
  GdkRegionPrivate *private2;
  GdkRegion *res;
  GdkRegionPrivate *res_private;

  g_return_val_if_fail (source1 != NULL, NULL);
  g_return_val_if_fail (source2 != NULL, NULL);

  private1 = (GdkRegionPrivate *) source1;
  private2 = (GdkRegionPrivate *) source2;

  res = gdk_region_new ();
  res_private = (GdkRegionPrivate *) res;
  
  CombineRgn (res_private->xregion, private1->xregion, private2->xregion,
	      RGN_AND);
  return res;
}

GdkRegion* 
gdk_regions_union (GdkRegion      *source1,
                   GdkRegion      *source2)
{
  GdkRegionPrivate *private1;
  GdkRegionPrivate *private2;
  GdkRegion *res;
  GdkRegionPrivate *res_private;

  g_return_val_if_fail (source1 != NULL, NULL);
  g_return_val_if_fail (source2 != NULL, NULL);

  private1 = (GdkRegionPrivate *) source1;
  private2 = (GdkRegionPrivate *) source2;

  res = gdk_region_new ();
  res_private = (GdkRegionPrivate *) res;
  
  CombineRgn (res_private->xregion, private1->xregion, private2->xregion,
	      RGN_OR);
  return res;
}

GdkRegion*    
gdk_regions_subtract (GdkRegion      *source1,
                      GdkRegion      *source2)
{
  GdkRegionPrivate *private1;
  GdkRegionPrivate *private2;
  GdkRegion *res;
  GdkRegionPrivate *res_private;

  g_return_val_if_fail (source1 != NULL, NULL);
  g_return_val_if_fail (source2 != NULL, NULL);

  private1 = (GdkRegionPrivate *) source1;
  private2 = (GdkRegionPrivate *) source2;

  res = gdk_region_new ();
  res_private = (GdkRegionPrivate *) res;
  
  CombineRgn (res_private->xregion, private1->xregion, private2->xregion,
	      RGN_DIFF);
  return res;
}

GdkRegion*    
gdk_regions_xor (GdkRegion      *source1,
                 GdkRegion      *source2)
{
  GdkRegionPrivate *private1;
  GdkRegionPrivate *private2;
  GdkRegion *res;
  GdkRegionPrivate *res_private;

  g_return_val_if_fail (source1 != NULL, NULL);
  g_return_val_if_fail (source2 != NULL, NULL);

  private1 = (GdkRegionPrivate *) source1;
  private2 = (GdkRegionPrivate *) source2;

  res = gdk_region_new ();
  res_private = (GdkRegionPrivate *) res;
  
  CombineRgn (res_private->xregion, private1->xregion, private2->xregion,
	      RGN_XOR);
  return res;
}