INTEGRATION: CWS svp01 (1.1.2); FILE ADDED

2006/05/31 14:37:43 thb 1.1.2.2: #i65904# Forgot return value
2006/05/31 14:08:53 thb 1.1.2.1: #i65904# Extracted cohen-sutherland rect clip tooling into exported header (needed for basebmp)

1 files changed, 98 insertions, 0 deletions

diff --git a/basegfx/inc/basegfx/tools/rectcliptools.hxx b/basegfx/inc/basegfx/tools/rectcliptools.hxx
new file mode 100644
index 000000000000..717e5afb263d
--- /dev/null
+++ b/basegfx/inc/basegfx/tools/rectcliptools.hxx
@@ -0,0 +1,98 @@
+/*************************************************************************
+ *
+ *  OpenOffice.org - a multi-platform office productivity suite
+ *
+ *  $RCSfile: rectcliptools.hxx,v $
+ *
+ *  $Revision: 1.2 $
+ *
+ *  last change: $Author: hr $ $Date: 2006-08-11 17:40:45 $
+ *
+ *  The Contents of this file are made available subject to
+ *  the terms of GNU Lesser General Public License Version 2.1.
+ *
+ *
+ *    GNU Lesser General Public License Version 2.1
+ *    =============================================
+ *    Copyright 2005 by Sun Microsystems, Inc.
+ *    901 San Antonio Road, Palo Alto, CA 94303, USA
+ *
+ *    This library is free software; you can redistribute it and/or
+ *    modify it under the terms of the GNU Lesser General Public
+ *    License version 2.1, as published by the Free Software Foundation.
+ *
+ *    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
+ *
+ ************************************************************************/
+
+#ifndef _BGFX_TOOLS_RECTCLIPTOOLS_HXX
+#define _BGFX_TOOLS_RECTCLIPTOOLS_HXX
+
+#ifndef _SAL_TYPES_H_
+#include <sal/types.h>
+#endif
+
+//////////////////////////////////////////////////////////////////////////////
+
+namespace basegfx
+{
+    namespace tools
+    {
+        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  = (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;
+        }
+
+        /** Determine number of clip planes hit by given clip mask
+
+            This method returns the number of one bits in the four
+            least significant bits of the argument, which amounts to
+            the number of clip planes hit within the
+            getCohenSutherlandClipFlags() method.
+         */
+        sal_uInt32 getNumberOfClipPlanes( sal_uInt32 nFlags )
+        {
+            // classic bit count algo, see e.g. Reingold, Nievergelt,
+            // Deo: Combinatorial Algorithms, Theory and Practice,
+            // Prentice-Hall 1977
+            nFlags = (nFlags & 0x05) + ((nFlags >> 1) & 0x05);
+            nFlags = (nFlags & 0x03) + (nFlags >> 2); // no need for &
+                                                      // 0x03, can't
+                                                      // overflow
+            return nFlags;
+        }
+    }
+}
+
+#endif // _BGFX_TOOLS_RECTCLIPTOOLS_HXX