include/basegfx/tools/rectcliptools.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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  19
  20 #ifndef INCLUDED_BASEGFX_TOOLS_RECTCLIPTOOLS_HXX
  21 #define INCLUDED_BASEGFX_TOOLS_RECTCLIPTOOLS_HXX
  22
  23 #include <sal/types.h>
  24 #include <basegfx/range/b2ibox.hxx>
  25
  26
  27 namespace basegfx
  28 {
  29     namespace tools
  30     {
  31         namespace RectClipFlags
  32         {
  33             static const sal_uInt32 LEFT   = (sal_Int32)0x01;
  34             static const sal_uInt32 RIGHT  = (sal_Int32)0x02;
  35             static const sal_uInt32 TOP    = (sal_Int32)0x04;
  36             static const sal_uInt32 BOTTOM = (sal_Int32)0x08;
  37         }
  38
  39         /** Calc clip mask for Cohen-Sutherland rectangle clip
  40
  41             This function returns a clip mask used for the
  42             Cohen-Sutherland rectangle clip method, where one or more
  43             of the lower four bits are set, if the given point is
  44             outside one or more of the four half planes defining the
  45             rectangle (see RectClipFlags for possible values)
  46          */
  47         template< class Point, class Rect > inline
  48            sal_uInt32 getCohenSutherlandClipFlags( const Point& rP,
  49                                                    const Rect&  rR )
  50         {
  51             // maxY | minY | maxX | minX
  52             sal_uInt32 clip  = (rP.getX() < rR.getMinX()) << 0;
  53                        clip |= (rP.getX() > rR.getMaxX()) << 1;
  54                        clip |= (rP.getY() < rR.getMinY()) << 2;
  55                        clip |= (rP.getY() > rR.getMaxY()) << 3;
  56             return clip;
  57         }
  58
  59         /// Cohen-Sutherland mask calculation - overload for boxes.
  60         template< class Point > inline
  61            sal_uInt32 getCohenSutherlandClipFlags( const Point&  rP,
  62                                                    const B2IBox& rB )
  63         {
  64             // maxY | minY | maxX | minX
  65             sal_uInt32 clip  = (rP.getX() <  rB.getMinX()) << 0;
  66                        clip |= (rP.getX() >= rB.getMaxX()) << 1;
  67                        clip |= (rP.getY() <  rB.getMinY()) << 2;
  68                        clip |= (rP.getY() >= rB.getMaxY()) << 3;
  69             return clip;
  70         }
  71
  72     }
  73 }
  74
  75 #endif // INCLUDED_BASEGFX_TOOLS_RECTCLIPTOOLS_HXX
  76
  77 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */