The GtkRadiant sources as originally released under the GPL license.

libs/gtkutil/xorrectangle.h

@@ -0,0 +1,125 @@
+/*
+Copyright (C) 2001-2006, William Joseph.
+All Rights Reserved.
+
+This file is part of GtkRadiant.
+
+GtkRadiant is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+GtkRadiant 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GtkRadiant; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#if !defined (INCLUDED_XORRECTANGLE_H)
+#define INCLUDED_XORRECTANGLE_H
+
+#include <gtk/gtkwidget.h>
+#include "math/vector.h"
+
+class rectangle_t
+{
+public:
+  rectangle_t()
+    : x(0), y(0), w(0), h(0)
+  {}
+  rectangle_t(float _x, float _y, float _w, float _h)
+    : x(_x), y(_y), w(_w), h(_h)
+  {}
+  float x;
+  float y;
+  float w;
+  float h;
+};
+
+struct Coord2D
+{
+  float x, y;
+  Coord2D(float _x, float _y)
+    : x(_x), y(_y)
+  {
+  }
+};
+
+inline Coord2D coord2d_device2screen(const Coord2D& coord, unsigned int width, unsigned int height)
+{
+  return Coord2D(((coord.x + 1.0f) * 0.5f) * width, ((coord.y + 1.0f) * 0.5f) * height);
+}
+
+inline rectangle_t rectangle_from_area(const float min[2], const float max[2], unsigned int width, unsigned int height)
+{
+  Coord2D botleft(coord2d_device2screen(Coord2D(min[0], min[1]), width, height));
+  Coord2D topright(coord2d_device2screen(Coord2D(max[0], max[1]), width, height));
+  return rectangle_t(botleft.x, botleft.y, topright.x - botleft.x, topright.y - botleft.y);
+}
+
+class XORRectangle
+{
+
+  rectangle_t m_rectangle;
+
+  GtkWidget* m_widget;
+  GdkGC* m_gc;
+
+  bool initialised() const
+  {
+    return m_gc != 0;
+  }
+  void lazy_init()
+  {
+    if(!initialised())
+    {
+      m_gc = gdk_gc_new(m_widget->window);
+
+      GdkColor color = { 0, 0xffff, 0xffff, 0xffff, };
+      GdkColormap* colormap = gdk_window_get_colormap(m_widget->window);
+      gdk_colormap_alloc_color (colormap, &color, FALSE, TRUE);
+      gdk_gc_copy(m_gc, m_widget->style->white_gc);
+      gdk_gc_set_foreground(m_gc, &color);
+      gdk_gc_set_background(m_gc, &color);
+
+      gdk_gc_set_function(m_gc, GDK_INVERT);
+    }
+  }
+  void draw() const
+  {
+    const int x = float_to_integer(m_rectangle.x);
+    const int y = float_to_integer(m_rectangle.y);
+    const int w = float_to_integer(m_rectangle.w);
+    const int h = float_to_integer(m_rectangle.h);
+    gdk_draw_rectangle(m_widget->window, m_gc, FALSE, x, -(h) - (y - m_widget->allocation.height), w, h);
+  }
+
+public:
+  XORRectangle(GtkWidget* widget) : m_widget(widget), m_gc(0)
+  {
+  }
+  ~XORRectangle()
+  {
+    if(initialised())
+    {
+      gdk_gc_unref(m_gc);
+    }
+  }
+  void set(rectangle_t rectangle)
+  {
+    if(GTK_WIDGET_REALIZED(m_widget))
+    {
+      lazy_init();
+      draw();
+      m_rectangle = rectangle;
+      draw();
+    }
+  }
+};
+
+
+#endif