gtk2/gdk/x11/gdkgc-x11.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 Lesser 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser 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 1997-2000.  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 "gdkgc.h"
#include "gdkprivate-x11.h"
#include "gdkregion-generic.h"
#include "gdkx.h"

#include <string.h>

typedef enum {
  GDK_GC_DIRTY_CLIP = 1 << 0,
  GDK_GC_DIRTY_TS = 1 << 1
} GdkGCDirtyValues;

static void gdk_x11_gc_values_to_xvalues (GdkGCValues    *values,
					  GdkGCValuesMask mask,
					  XGCValues      *xvalues,
					  unsigned long  *xvalues_mask);

static void gdk_x11_gc_get_values (GdkGC           *gc,
				   GdkGCValues     *values);
static void gdk_x11_gc_set_values (GdkGC           *gc,
				   GdkGCValues     *values,
				   GdkGCValuesMask  values_mask);
static void gdk_x11_gc_set_dashes (GdkGC           *gc,
				   gint             dash_offset,
				   gint8            dash_list[],
				   gint             n);

static void gdk_gc_x11_class_init (GdkGCX11Class *klass);
static void gdk_gc_x11_finalize   (GObject           *object);

static gpointer parent_class = NULL;

GType
_gdk_gc_x11_get_type (void)
{
  static GType object_type = 0;

  if (!object_type)
    {
      static const GTypeInfo object_info =
      {
        sizeof (GdkGCX11Class),
        (GBaseInitFunc) NULL,
        (GBaseFinalizeFunc) NULL,
        (GClassInitFunc) gdk_gc_x11_class_init,
        NULL,           /* class_finalize */
        NULL,           /* class_data */
        sizeof (GdkGCX11),
        0,              /* n_preallocs */
        (GInstanceInitFunc) NULL,
      };
      
      object_type = g_type_register_static (GDK_TYPE_GC,
                                            "GdkGCX11",
                                            &object_info, 0);
    }
  
  return object_type;
}

static void
gdk_gc_x11_class_init (GdkGCX11Class *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);
  GdkGCClass *gc_class = GDK_GC_CLASS (klass);
  
  parent_class = g_type_class_peek_parent (klass);

  object_class->finalize = gdk_gc_x11_finalize;

  gc_class->get_values = gdk_x11_gc_get_values;
  gc_class->set_values = gdk_x11_gc_set_values;
  gc_class->set_dashes = gdk_x11_gc_set_dashes;
}

static void
gdk_gc_x11_finalize (GObject *object)
{
  GdkGCX11 *x11_gc = GDK_GC_X11 (object);
  
  if (x11_gc->clip_region)
    gdk_region_destroy (x11_gc->clip_region);
  
  if (x11_gc->fg_picture != None)
    XRenderFreePicture (GDK_GC_XDISPLAY (x11_gc), x11_gc->fg_picture);
  
  XFreeGC (GDK_GC_XDISPLAY (x11_gc), GDK_GC_XGC (x11_gc));

  G_OBJECT_CLASS (parent_class)->finalize (object);
}


GdkGC *
_gdk_x11_gc_new (GdkDrawable      *drawable,
		 GdkGCValues      *values,
		 GdkGCValuesMask   values_mask)
{
  GdkGC *gc;
  GdkGCX11 *private;
  
  XGCValues xvalues;
  unsigned long xvalues_mask;

  /* NOTICE that the drawable here has to be the impl drawable,
   * not the publically-visible drawables.
   */
  g_return_val_if_fail (GDK_IS_DRAWABLE_IMPL_X11 (drawable), NULL);

  gc = g_object_new (_gdk_gc_x11_get_type (), NULL);
  private = GDK_GC_X11 (gc);

  private->dirty_mask = 0;
  private->have_clip_mask = FALSE;
  private->clip_region = NULL;
    
  private->screen = GDK_DRAWABLE_IMPL_X11 (drawable)->screen;

  private->depth = gdk_drawable_get_depth (drawable);

  if (values_mask & (GDK_GC_CLIP_X_ORIGIN | GDK_GC_CLIP_Y_ORIGIN))
    {
      values_mask &= ~(GDK_GC_CLIP_X_ORIGIN | GDK_GC_CLIP_Y_ORIGIN);
      private->dirty_mask |= GDK_GC_DIRTY_CLIP;
    }

  if (values_mask & (GDK_GC_TS_X_ORIGIN | GDK_GC_TS_Y_ORIGIN))
    {
      values_mask &= ~(GDK_GC_TS_X_ORIGIN | GDK_GC_TS_Y_ORIGIN);
      private->dirty_mask |= GDK_GC_DIRTY_TS;
    }

  if (values_mask & GDK_GC_FOREGROUND)
    private->fg_pixel = values->foreground.pixel;

  if ((values_mask & GDK_GC_CLIP_MASK) && values->clip_mask)
    private->have_clip_mask = TRUE;

  xvalues.function = GXcopy;
  xvalues.fill_style = FillSolid;
  xvalues.arc_mode = ArcPieSlice;
  xvalues.subwindow_mode = ClipByChildren;
  xvalues.graphics_exposures = False;
  xvalues_mask = GCFunction | GCFillStyle | GCArcMode | GCSubwindowMode | GCGraphicsExposures;

  gdk_x11_gc_values_to_xvalues (values, values_mask, &xvalues, &xvalues_mask);
  
  private->xgc = XCreateGC (GDK_GC_XDISPLAY (gc),
                            GDK_DRAWABLE_IMPL_X11 (drawable)->xid,
                            xvalues_mask, &xvalues);

  return gc;
}

GC
_gdk_x11_gc_flush (GdkGC *gc)
{
  GdkGCX11 *private = GDK_GC_X11 (gc);

  if (private->dirty_mask & GDK_GC_DIRTY_CLIP)
    {
      if (!private->clip_region)
	XSetClipOrigin (GDK_GC_XDISPLAY (gc), GDK_GC_XGC (gc),
			gc->clip_x_origin, gc->clip_y_origin);
      else
	{
	  XRectangle *rectangles;
          gint n_rects;

          _gdk_region_get_xrectangles (private->clip_region,
                                       gc->clip_x_origin,
                                       gc->clip_y_origin,
                                       &rectangles,
                                       &n_rects);
	  
	  XSetClipRectangles (GDK_GC_XDISPLAY (gc), GDK_GC_XGC (gc), 0, 0,
                              rectangles,
                              n_rects, YXBanded);
          
	  g_free (rectangles);
	}
    }

  if (private->dirty_mask & GDK_GC_DIRTY_TS)
    {
      XSetTSOrigin (GDK_GC_XDISPLAY (gc), GDK_GC_XGC (gc),
		    gc->ts_x_origin, gc->ts_y_origin);
    }

  private->dirty_mask = 0;
  return GDK_GC_XGC (gc);
}

static void
gdk_x11_gc_get_values (GdkGC       *gc,
		       GdkGCValues *values)
{
  XGCValues xvalues;
  
  if (XGetGCValues (GDK_GC_XDISPLAY (gc), GDK_GC_XGC (gc),
		    GCForeground | GCBackground | GCFont |
		    GCFunction | GCTile | GCStipple | /* GCClipMask | */
		    GCSubwindowMode | GCGraphicsExposures |
		    GCTileStipXOrigin | GCTileStipYOrigin |
		    GCClipXOrigin | GCClipYOrigin |
		    GCLineWidth | GCLineStyle | GCCapStyle |
		    GCFillStyle | GCJoinStyle, &xvalues))
    {
      values->foreground.pixel = xvalues.foreground;
      values->background.pixel = xvalues.background;
      values->font = gdk_font_lookup_for_display (GDK_GC_DISPLAY (gc),
						  xvalues.font);

      switch (xvalues.function)
	{
	case GXcopy:
	  values->function = GDK_COPY;
	  break;
	case GXinvert:
	  values->function = GDK_INVERT;
	  break;
	case GXxor:
	  values->function = GDK_XOR;
	  break;
	case GXclear:
	  values->function = GDK_CLEAR;
	  break;
	case GXand:
	  values->function = GDK_AND;
	  break;
	case GXandReverse:
	  values->function = GDK_AND_REVERSE;
	  break;
	case GXandInverted:
	  values->function = GDK_AND_INVERT;
	  break;
	case GXnoop:
	  values->function = GDK_NOOP;
	  break;
	case GXor:
	  values->function = GDK_OR;
	  break;
	case GXequiv:
	  values->function = GDK_EQUIV;
	  break;
	case GXorReverse:
	  values->function = GDK_OR_REVERSE;
	  break;
	case GXcopyInverted:
	  values->function =GDK_COPY_INVERT;
	  break;
	case GXorInverted:
	  values->function = GDK_OR_INVERT;
	  break;
	case GXnand:
	  values->function = GDK_NAND;
	  break;
	case GXset:
	  values->function = GDK_SET;
	  break;
	case GXnor:
	  values->function = GDK_NOR;
	  break;
	}

      switch (xvalues.fill_style)
	{
	case FillSolid:
	  values->fill = GDK_SOLID;
	  break;
	case FillTiled:
	  values->fill = GDK_TILED;
	  break;
	case FillStippled:
	  values->fill = GDK_STIPPLED;
	  break;
	case FillOpaqueStippled:
	  values->fill = GDK_OPAQUE_STIPPLED;
	  break;
	}

      values->tile = gdk_pixmap_lookup_for_display (GDK_GC_DISPLAY (gc),
						    xvalues.tile);
      values->stipple = gdk_pixmap_lookup_for_display (GDK_GC_DISPLAY (gc),
						       xvalues.stipple);
      values->clip_mask = NULL;
      values->subwindow_mode = xvalues.subwindow_mode;
      values->ts_x_origin = xvalues.ts_x_origin;
      values->ts_y_origin = xvalues.ts_y_origin;
      values->clip_x_origin = xvalues.clip_x_origin;
      values->clip_y_origin = xvalues.clip_y_origin;
      values->graphics_exposures = xvalues.graphics_exposures;
      values->line_width = xvalues.line_width;

      switch (xvalues.line_style)
	{
	case LineSolid:
	  values->line_style = GDK_LINE_SOLID;
	  break;
	case LineOnOffDash:
	  values->line_style = GDK_LINE_ON_OFF_DASH;
	  break;
	case LineDoubleDash:
	  values->line_style = GDK_LINE_DOUBLE_DASH;
	  break;
	}

      switch (xvalues.cap_style)
	{
	case CapNotLast:
	  values->cap_style = GDK_CAP_NOT_LAST;
	  break;
	case CapButt:
	  values->cap_style = GDK_CAP_BUTT;
	  break;
	case CapRound:
	  values->cap_style = GDK_CAP_ROUND;
	  break;
	case CapProjecting:
	  values->cap_style = GDK_CAP_PROJECTING;
	  break;
	}

      switch (xvalues.join_style)
	{
	case JoinMiter:
	  values->join_style = GDK_JOIN_MITER;
	  break;
	case JoinRound:
	  values->join_style = GDK_JOIN_ROUND;
	  break;
	case JoinBevel:
	  values->join_style = GDK_JOIN_BEVEL;
	  break;
	}
    }
  else
    {
      memset (values, 0, sizeof (GdkGCValues));
    }
}


static void
gdk_x11_gc_set_values (GdkGC           *gc,
		       GdkGCValues     *values,
		       GdkGCValuesMask  values_mask)
{
  GdkGCX11 *x11_gc;
  XGCValues xvalues;
  unsigned long xvalues_mask = 0;

  x11_gc = GDK_GC_X11 (gc);

  if (values_mask & (GDK_GC_CLIP_X_ORIGIN | GDK_GC_CLIP_Y_ORIGIN))
    {
      values_mask &= ~(GDK_GC_CLIP_X_ORIGIN | GDK_GC_CLIP_Y_ORIGIN);
      x11_gc->dirty_mask |= GDK_GC_DIRTY_CLIP;
    }

  if (values_mask & (GDK_GC_TS_X_ORIGIN | GDK_GC_TS_Y_ORIGIN))
    {
      values_mask &= ~(GDK_GC_TS_X_ORIGIN | GDK_GC_TS_Y_ORIGIN);
      x11_gc->dirty_mask |= GDK_GC_DIRTY_TS;
    }

  if (values_mask & GDK_GC_CLIP_MASK)
    {
      if (x11_gc->clip_region)
	{
	  gdk_region_destroy (x11_gc->clip_region);
	  x11_gc->clip_region = NULL;
	}

      x11_gc->have_clip_mask = values->clip_mask != NULL;
    }

  if (values_mask & GDK_GC_FOREGROUND)
    x11_gc->fg_pixel = values->foreground.pixel;
  
  gdk_x11_gc_values_to_xvalues (values, values_mask, &xvalues, &xvalues_mask);

  XChangeGC (GDK_GC_XDISPLAY (gc),
	     GDK_GC_XGC (gc),
	     xvalues_mask,
	     &xvalues);
}

static void
gdk_x11_gc_set_dashes (GdkGC *gc,
		       gint   dash_offset,
		       gint8  dash_list[],
		       gint   n)
{
  g_return_if_fail (GDK_IS_GC (gc));
  g_return_if_fail (dash_list != NULL);

  XSetDashes (GDK_GC_XDISPLAY (gc), GDK_GC_XGC (gc),
	      dash_offset, dash_list, n);
}

static void
gdk_x11_gc_values_to_xvalues (GdkGCValues    *values,
			      GdkGCValuesMask mask,
			      XGCValues      *xvalues,
			      unsigned long  *xvalues_mask)
{
  /* Optimization for the common case (gdk_gc_new()) */
  if (values == NULL || mask == 0)
    return;
  
  if (mask & GDK_GC_FOREGROUND)
    {
      xvalues->foreground = values->foreground.pixel;
      *xvalues_mask |= GCForeground;
    }
  if (mask & GDK_GC_BACKGROUND)
    {
      xvalues->background = values->background.pixel;
      *xvalues_mask |= GCBackground;
    }
  if ((mask & GDK_GC_FONT) && (values->font->type == GDK_FONT_FONT))
    {
      xvalues->font = ((XFontStruct *) (GDK_FONT_XFONT (values->font)))->fid;
      *xvalues_mask |= GCFont;
    }
  if (mask & GDK_GC_FUNCTION)
    {
      switch (values->function)
	{
	case GDK_COPY:
	  xvalues->function = GXcopy;
	  break;
	case GDK_INVERT:
	  xvalues->function = GXinvert;
	  break;
	case GDK_XOR:
	  xvalues->function = GXxor;
	  break;
	case GDK_CLEAR:
	  xvalues->function = GXclear;
	  break;
	case GDK_AND:
	  xvalues->function = GXand;
	  break;
	case GDK_AND_REVERSE:
	  xvalues->function = GXandReverse;
	  break;
	case GDK_AND_INVERT:
	  xvalues->function = GXandInverted;
	  break;
	case GDK_NOOP:
	  xvalues->function = GXnoop;
	  break;
	case GDK_OR:
	  xvalues->function = GXor;
	  break;
	case GDK_EQUIV:
	  xvalues->function = GXequiv;
	  break;
	case GDK_OR_REVERSE:
	  xvalues->function = GXorReverse;
	  break;
	case GDK_COPY_INVERT:
	  xvalues->function = GXcopyInverted;
	  break;
	case GDK_OR_INVERT:
	  xvalues->function = GXorInverted;
	  break;
	case GDK_NAND:
	  xvalues->function = GXnand;
	  break;
	case GDK_SET:
	  xvalues->function = GXset;
	  break;
	case GDK_NOR:
	  xvalues->function = GXnor;
	  break;
	}
      *xvalues_mask |= GCFunction;
    }
  if (mask & GDK_GC_FILL)
    {
      switch (values->fill)
	{
	case GDK_SOLID:
	  xvalues->fill_style = FillSolid;
	  break;
	case GDK_TILED:
	  xvalues->fill_style = FillTiled;
	  break;
	case GDK_STIPPLED:
	  xvalues->fill_style = FillStippled;
	  break;
	case GDK_OPAQUE_STIPPLED:
	  xvalues->fill_style = FillOpaqueStippled;
	  break;
	}
      *xvalues_mask |= GCFillStyle;
    }
  if (mask & GDK_GC_TILE)
    {
      if (values->tile)
	xvalues->tile = GDK_DRAWABLE_XID (values->tile);
      else
	xvalues->tile = None;
      
      *xvalues_mask |= GCTile;
    }
  if (mask & GDK_GC_STIPPLE)
    {
      if (values->stipple)
	xvalues->stipple = GDK_DRAWABLE_XID (values->stipple);
      else
	xvalues->stipple = None;
      
      *xvalues_mask |= GCStipple;
    }
  if (mask & GDK_GC_CLIP_MASK)
    {
      if (values->clip_mask)
	xvalues->clip_mask = GDK_DRAWABLE_XID (values->clip_mask);
      else
	xvalues->clip_mask = None;

      *xvalues_mask |= GCClipMask;
      
    }
  if (mask & GDK_GC_SUBWINDOW)
    {
      xvalues->subwindow_mode = values->subwindow_mode;
      *xvalues_mask |= GCSubwindowMode;
    }
  if (mask & GDK_GC_TS_X_ORIGIN)
    {
      xvalues->ts_x_origin = values->ts_x_origin;
      *xvalues_mask |= GCTileStipXOrigin;
    }
  if (mask & GDK_GC_TS_Y_ORIGIN)
    {
      xvalues->ts_y_origin = values->ts_y_origin;
      *xvalues_mask |= GCTileStipYOrigin;
    }
  if (mask & GDK_GC_CLIP_X_ORIGIN)
    {
      xvalues->clip_x_origin = values->clip_x_origin;
      *xvalues_mask |= GCClipXOrigin;
    }
  if (mask & GDK_GC_CLIP_Y_ORIGIN)
    {
      xvalues->clip_y_origin = values->clip_y_origin;
      *xvalues_mask |= GCClipYOrigin;
    }

  if (mask & GDK_GC_EXPOSURES)
    {
      xvalues->graphics_exposures = values->graphics_exposures;
      *xvalues_mask |= GCGraphicsExposures;
    }

  if (mask & GDK_GC_LINE_WIDTH)
    {
      xvalues->line_width = values->line_width;
      *xvalues_mask |= GCLineWidth;
    }
  if (mask & GDK_GC_LINE_STYLE)
    {
      switch (values->line_style)
	{
	case GDK_LINE_SOLID:
	  xvalues->line_style = LineSolid;
	  break;
	case GDK_LINE_ON_OFF_DASH:
	  xvalues->line_style = LineOnOffDash;
	  break;
	case GDK_LINE_DOUBLE_DASH:
	  xvalues->line_style = LineDoubleDash;
	  break;
	}
      *xvalues_mask |= GCLineStyle;
    }
  if (mask & GDK_GC_CAP_STYLE)
    {
      switch (values->cap_style)
	{
	case GDK_CAP_NOT_LAST:
	  xvalues->cap_style = CapNotLast;
	  break;
	case GDK_CAP_BUTT:
	  xvalues->cap_style = CapButt;
	  break;
	case GDK_CAP_ROUND:
	  xvalues->cap_style = CapRound;
	  break;
	case GDK_CAP_PROJECTING:
	  xvalues->cap_style = CapProjecting;
	  break;
	}
      *xvalues_mask |= GCCapStyle;
    }
  if (mask & GDK_GC_JOIN_STYLE)
    {
      switch (values->join_style)
	{
	case GDK_JOIN_MITER:
	  xvalues->join_style = JoinMiter;
	  break;
	case GDK_JOIN_ROUND:
	  xvalues->join_style = JoinRound;
	  break;
	case GDK_JOIN_BEVEL:
	  xvalues->join_style = JoinBevel;
	  break;
	}
      *xvalues_mask |= GCJoinStyle;
    }

}

void
gdk_gc_set_clip_rectangle (GdkGC	*gc,
			   GdkRectangle *rectangle)
{
  GdkGCX11 *x11_gc;
  gboolean had_region = FALSE;
  
  g_return_if_fail (GDK_IS_GC (gc));

  x11_gc = GDK_GC_X11 (gc);

  if (x11_gc->clip_region)
    {
      had_region = TRUE;
      gdk_region_destroy (x11_gc->clip_region);
    }

  if (rectangle)
    x11_gc->clip_region = gdk_region_rectangle (rectangle);
  else
    x11_gc->clip_region = NULL;

  /* Unset immediately, to make sure Xlib doesn't keep the
   * XID of an old clip mask cached
   */
  if ((had_region && !rectangle) || x11_gc->have_clip_mask)
    {
      XSetClipMask (GDK_GC_XDISPLAY (gc), GDK_GC_XGC (gc), None);
      x11_gc->have_clip_mask = FALSE;
    }

  gc->clip_x_origin = 0;
  gc->clip_y_origin = 0;
  
  x11_gc->dirty_mask |= GDK_GC_DIRTY_CLIP;
}

void
gdk_gc_set_clip_region (GdkGC	  *gc,
			GdkRegion *region)
{
  GdkGCX11 *x11_gc;
  gboolean had_region = FALSE;

  g_return_if_fail (GDK_IS_GC (gc));

  x11_gc = GDK_GC_X11 (gc);

  if (x11_gc->clip_region)
    {
      had_region = TRUE;
      gdk_region_destroy (x11_gc->clip_region);
    }

  if (region)
    x11_gc->clip_region = gdk_region_copy (region);
  else
    x11_gc->clip_region = NULL;    

  /* Unset immediately, to make sure Xlib doesn't keep the
   * XID of an old clip mask cached
   */
  if ((had_region && !region) || x11_gc->have_clip_mask)
    {
      XSetClipMask (GDK_GC_XDISPLAY (gc), GDK_GC_XGC (gc), None);
      x11_gc->have_clip_mask = FALSE;
    }

  gc->clip_x_origin = 0;
  gc->clip_y_origin = 0;
  
  x11_gc->dirty_mask |= GDK_GC_DIRTY_CLIP;
}


void
gdk_gc_copy (GdkGC *dst_gc, GdkGC *src_gc)
{
  GdkGCX11 *x11_src_gc;
  GdkGCX11 *x11_dst_gc;
  
  g_return_if_fail (GDK_IS_GC_X11 (dst_gc));
  g_return_if_fail (GDK_IS_GC_X11 (src_gc));

  x11_dst_gc = GDK_GC_X11 (dst_gc);
  x11_src_gc = GDK_GC_X11 (src_gc);
  
  XCopyGC (GDK_GC_XDISPLAY (src_gc), GDK_GC_XGC (src_gc), ~((~1) << GCLastBit),
	   GDK_GC_XGC (dst_gc));

  dst_gc->clip_x_origin = src_gc->clip_x_origin;
  dst_gc->clip_y_origin = src_gc->clip_y_origin;
  dst_gc->ts_x_origin = src_gc->ts_x_origin;
  dst_gc->ts_y_origin = src_gc->ts_y_origin;

  if (src_gc->colormap)
    g_object_ref (src_gc->colormap);

  if (dst_gc->colormap)
    g_object_unref (dst_gc->colormap);

  dst_gc->colormap = src_gc->colormap;

  if (x11_dst_gc->clip_region)
    gdk_region_destroy (x11_dst_gc->clip_region);

  if (x11_src_gc->clip_region)
    x11_dst_gc->clip_region = gdk_region_copy (x11_src_gc->clip_region);
  else
    x11_dst_gc->clip_region = NULL;

  x11_dst_gc->dirty_mask = x11_src_gc->dirty_mask;
  x11_dst_gc->fg_pixel = x11_src_gc->fg_pixel;
}

/**
 * gdk_gc_get_screen:
 * @gc: a #GdkGC.
 *
 * Gets the #GdkScreen for which @gc was created
 *
 * Returns: the #GdkScreen for @gc.
 *
 * Since: 2.2
 */
GdkScreen *  
gdk_gc_get_screen (GdkGC *gc)
{
  g_return_val_if_fail (GDK_IS_GC_X11 (gc), NULL);
  
  return GDK_GC_X11 (gc)->screen;
}

/**
 * gdk_x11_gc_get_xdisplay:
 * @gc: a #GdkGC.
 * 
 * Returns the display of a #GdkGC.
 * 
 * Return value: an Xlib <type>Display*</type>.
 **/
Display *
gdk_x11_gc_get_xdisplay (GdkGC *gc)
{
  g_return_val_if_fail (GDK_IS_GC_X11 (gc), NULL);

  return GDK_SCREEN_XDISPLAY (gdk_gc_get_screen (gc));
}

/**
 * gdk_x11_gc_get_xgc:
 * @gc: a #GdkGC.
 * 
 * Returns the X GC of a #GdkGC.
 * 
 * Return value: an Xlib <type>GC</type>.
 **/
GC
gdk_x11_gc_get_xgc (GdkGC *gc)
{
  GdkGCX11 *gc_x11;
  
  g_return_val_if_fail (GDK_IS_GC_X11 (gc), NULL);

  gc_x11 = GDK_GC_X11 (gc);

  if (gc_x11->dirty_mask)
    _gdk_x11_gc_flush (gc);

  return gc_x11->xgc;
}

/* Various bits of the below are roughly cribbed from XFree86
 * lib/Xft/xftdraw.c, Copyright 2000, Keith Packard
 */

static XRenderPictFormat *
foreground_format (GdkGC *gc)
{
  XRenderPictFormat pf;

  pf.type = PictTypeDirect;
  pf.depth = 32;
  pf.direct.redMask = 0xff;
  pf.direct.greenMask = 0xff;
  pf.direct.blueMask = 0xff;
  pf.direct.alphaMask = 0xff;

  return XRenderFindFormat (GDK_GC_XDISPLAY (gc),
			    (PictFormatType |
			     PictFormatDepth |
			     PictFormatRedMask |
			     PictFormatGreenMask |
			     PictFormatBlueMask |
			     PictFormatAlphaMask),
			    &pf,
			    0);
}

/**
 * _gdk_x11_gc_get_fg_picture:
 * @gc: a #GdkGC
 * 
 * Gets a Xrender Picture object suitable for being the source
 * drawable for drawing with the foreground the graphics context.
 * (Currently, only foreground color is handled, but in the
 * future we should handle tiles/stipples as well.)
 * 
 * Return value: a Picture, owned by the GC; this cannot be
 *   used over subsequent modification of the GC.
 **/
Picture
_gdk_x11_gc_get_fg_picture (GdkGC *gc)
{
  GdkGCX11 *x11_gc;
  gboolean new = FALSE;
  XftColor xftcolor;
  
  g_return_val_if_fail (GDK_IS_GC_X11 (gc), None);

  if (!_gdk_x11_have_render (GDK_GC_DISPLAY (gc)))
    return None;

  x11_gc = GDK_GC_X11 (gc);

  if (x11_gc->fg_picture == None)
    {
      XRenderPictureAttributes pa;
      XRenderPictFormat *pix_format = foreground_format (gc);
      Pixmap pix;

      if (!pix_format)
	return None;

      pix = XCreatePixmap (GDK_GC_XDISPLAY (gc), 
			   GDK_SCREEN_XROOTWIN (x11_gc->screen),
			   1, 1, pix_format->depth);
      pa.repeat = True;
      x11_gc->fg_picture = XRenderCreatePicture (GDK_GC_XDISPLAY (gc), 
						 pix,
						 pix_format,
						 CPRepeat, &pa);
      XFreePixmap (GDK_GC_XDISPLAY (gc), pix);
      
      new = TRUE;
    }

  _gdk_gc_x11_get_fg_xft_color (gc, &xftcolor);
  
  if (new ||
      x11_gc->fg_picture_color.red != xftcolor.color.red ||
      x11_gc->fg_picture_color.green != xftcolor.color.green ||
      x11_gc->fg_picture_color.blue != xftcolor.color.blue)
    {
      x11_gc->fg_picture_color.red = xftcolor.color.red;
      x11_gc->fg_picture_color.green = xftcolor.color.green;
      x11_gc->fg_picture_color.blue = xftcolor.color.blue;

      XRenderFillRectangle (GDK_GC_XDISPLAY (gc), PictOpSrc, 
			    x11_gc->fg_picture, &x11_gc->fg_picture_color,
			    0, 0, 1, 1); 
    }

  return x11_gc->fg_picture;
}

/**
 * _gdk_gc_x11_get_fg_xft_color:
 * @gc: a #GdkGC
 * @xftcolor: location to store the color
 * 
 * Gets the foreground color of the GC as a XftColor.
 **/
void
_gdk_gc_x11_get_fg_xft_color (GdkGC    *gc,
			      XftColor *xftcolor)
{
  GdkGCX11 *x11_gc;
  GdkColormap *cmap;
  GdkColor color;
  
  g_return_if_fail (GDK_IS_GC_X11 (gc));

  x11_gc = GDK_GC_X11 (gc);

  cmap = gdk_gc_get_colormap (gc);

  xftcolor->pixel = x11_gc->fg_pixel;

  if (cmap)
    {
      gdk_colormap_query_color (cmap, xftcolor->pixel, &color);
      xftcolor->color.alpha = 0xffff;
      xftcolor->color.red = color.red;
      xftcolor->color.green = color.green;
      xftcolor->color.blue = color.blue;
    }
  else if (x11_gc->depth == 1)
    {
      /* Drawing with Xft on a bitmap is a bit bizzare; it
       * takes alpha >= 0x8000 to mean 'set to 1' and
       * alpha < 0x8000 to mean 'set to 0'.
       */
      if (xftcolor->pixel)
        {
	  xftcolor->color.red = 0xffff;
	  xftcolor->color.green = 0xffff;
	  xftcolor->color.blue = 0xffff;
	  xftcolor->color.alpha = 0xffff;
	}
      else
        {
	  xftcolor->color.red = 0;
	  xftcolor->color.green = 0;
	  xftcolor->color.blue = 0;
	  xftcolor->color.alpha = 0;
	}
    }
  else
    {
      g_warning ("Using Xft rendering requires the GC argument to have a\n"
		 "specified colormap. If the GC was created for a drawable\n"
		 "with a colormap, the colormap will be set on the GC\n"
		 "automatically. Otherwise, a colormap must be set on it with"
		 "gdk_gc_set_colormap");
    }
}