basegfx/source/range/b2xrange.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
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   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #include <basegfx/range/b2drange.hxx>
  21 #include <basegfx/range/b2irange.hxx>
  22 #include <basegfx/range/b2ibox.hxx>
  23
  24
  25 namespace basegfx
  26 {
  27     namespace
  28     {
  29         /** Generic implementation of the difference set computation
  30
  31             @tpl RangeType
  32             Type to operate on. Must provide ValueType and TraitsType
  33             nested types.
  34          */
  35         template< class RangeType > void doComputeSetDifference(
  36             ::std::vector< RangeType >& o_rRanges,
  37             const RangeType&            a,
  38             const RangeType&            b )
  39         {
  40             o_rRanges.clear();
  41
  42             // special-casing the empty rect case (this will fail most
  43             // of the times below, because of the DBL_MIN/MAX special
  44             // values denoting emptyness in the rectangle.
  45             if( a.isEmpty() )
  46             {
  47                 o_rRanges.push_back( b );
  48                 return;
  49             }
  50             if( b.isEmpty() )
  51             {
  52                 o_rRanges.push_back( a );
  53                 return;
  54             }
  55
  56             const typename RangeType::ValueType                     ax(a.getMinX());
  57             const typename RangeType::ValueType                     ay(a.getMinY());
  58             const typename RangeType::TraitsType::DifferenceType    aw(a.getWidth());
  59             const typename RangeType::TraitsType::DifferenceType    ah(a.getHeight());
  60             const typename RangeType::ValueType                     bx(b.getMinX());
  61             const typename RangeType::ValueType                     by(b.getMinY());
  62             const typename RangeType::TraitsType::DifferenceType    bw(b.getWidth());
  63             const typename RangeType::TraitsType::DifferenceType    bh(b.getHeight());
  64
  65             const typename RangeType::TraitsType::DifferenceType    h0( (by > ay) ? by - ay : 0 );
  66             const typename RangeType::TraitsType::DifferenceType    h3( (by + bh < ay + ah) ? ay + ah - by - bh : 0 );
  67             const typename RangeType::TraitsType::DifferenceType    w1( (bx > ax) ? bx - ax : 0 );
  68             const typename RangeType::TraitsType::DifferenceType    w2( (ax + aw > bx + bw) ? ax + aw - bx - bw : 0 );
  69             const typename RangeType::TraitsType::DifferenceType    h12( (h0 + h3 < ah) ? ah - h0 - h3 : 0 );
  70
  71             // TODO(E2): Use numeric_cast instead of static_cast here,
  72             // need range checks!
  73             if (h0 > 0)
  74                 o_rRanges.push_back(
  75                     RangeType(ax,ay,
  76                               static_cast<typename RangeType::ValueType>(ax+aw),
  77                               static_cast<typename RangeType::ValueType>(ay+h0)) );
  78
  79             if (w1 > 0 && h12 > 0)
  80                 o_rRanges.push_back(
  81                     RangeType(ax,
  82                               static_cast<typename RangeType::ValueType>(ay+h0),
  83                               static_cast<typename RangeType::ValueType>(ax+w1),
  84                               static_cast<typename RangeType::ValueType>(ay+h0+h12)) );
  85
  86             if (w2 > 0 && h12 > 0)
  87                 o_rRanges.push_back(
  88                     RangeType(static_cast<typename RangeType::ValueType>(bx+bw),
  89                               static_cast<typename RangeType::ValueType>(ay+h0),
  90                               static_cast<typename RangeType::ValueType>(bx+bw+w2),
  91                               static_cast<typename RangeType::ValueType>(ay+h0+h12)) );
  92
  93             if (h3 > 0)
  94                 o_rRanges.push_back(
  95                     RangeType(ax,
  96                               static_cast<typename RangeType::ValueType>(ay+h0+h12),
  97                               static_cast<typename RangeType::ValueType>(ax+aw),
  98                               static_cast<typename RangeType::ValueType>(ay+h0+h12+h3)) );
  99         }
 100     }
 101
 102     ::std::vector< B2IRange >& computeSetDifference( ::std::vector< B2IRange >& o_rResult,
 103                                                      const B2IRange&            rFirst,
 104                                                      const B2IRange&            rSecond )
 105     {
 106         doComputeSetDifference( o_rResult, rFirst, rSecond );
 107
 108         return o_rResult;
 109     }
 110
 111     ::std::vector< B2DRange >& computeSetDifference( ::std::vector< B2DRange >& o_rResult,
 112                                                      const B2DRange&            rFirst,
 113                                                      const B2DRange&            rSecond )
 114     {
 115         doComputeSetDifference( o_rResult, rFirst, rSecond );
 116
 117         return o_rResult;
 118     }
 119
 120 } // end of namespace basegfx
 121
 122 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */