1 files changed, 72 insertions, 0 deletions
diff --git a/include/basegfx/utils/rectcliptools.hxx b/include/basegfx/utils/rectcliptools.hxx
new file mode 100644
index 000000000..b1354a6ca
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+++ b/include/basegfx/utils/rectcliptools.hxx
@@ -0,0 +1,72 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#pragma once
+
+#include <sal/types.h>
+#include <basegfx/range/b2ibox.hxx>
+
+
+namespace basegfx::utils
+{
+    namespace RectClipFlags
+    {
+        static const sal_uInt32 LEFT   = sal_Int32(0x01);
+        static const sal_uInt32 RIGHT  = sal_Int32(0x02);
+        static const sal_uInt32 TOP    = sal_Int32(0x04);
+        static const sal_uInt32 BOTTOM = sal_Int32(0x08);
+    }
+
+    /** Calc clip mask for Cohen-Sutherland rectangle clip
+
+        This function returns a clip mask used for the
+        Cohen-Sutherland rectangle clip method, where one or more
+        of the lower four bits are set, if the given point is
+        outside one or more of the four half planes defining the
+        rectangle (see RectClipFlags for possible values)
+     */
+    template< class Point, class Rect > inline
+       sal_uInt32 getCohenSutherlandClipFlags( const Point& rP,
+                                               const Rect&  rR )
+    {
+        // maxY | minY | maxX | minX
+        sal_uInt32 clip;
+        clip = (rP.getX() < rR.getMinX()) << 0;
+        clip |= (rP.getX() > rR.getMaxX()) << 1;
+        clip |= (rP.getY() < rR.getMinY()) << 2;
+        clip |= (rP.getY() > rR.getMaxY()) << 3;
+        return clip;
+    }
+
+    /// Cohen-Sutherland mask calculation - overload for boxes.
+    template< class Point > inline
+       sal_uInt32 getCohenSutherlandClipFlags( const Point&  rP,
+                                               const B2IBox& rB )
+    {
+        // maxY | minY | maxX | minX
+        sal_uInt32 clip;
+        clip = (rP.getX() <  rB.getMinX()) << 0;
+        clip |= (rP.getX() >= rB.getMaxX()) << 1;
+        clip |= (rP.getY() <  rB.getMinY()) << 2;
+        clip |= (rP.getY() >= rB.getMaxY()) << 3;
+        return clip;
+    }
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */