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.
   4  *
   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 namespace basegfx
  25 {
  26     namespace
  27     {
  28         /** Generic implementation of the difference set computation
  29
  30             @tpl RangeType
  31             Type to operate on. Must provide ValueType and TraitsType
  32             nested types.
  33          */
  34         template< class RangeType > void doComputeSetDifference(
  35             ::std::vector< RangeType >& o_rRanges,
  36             const RangeType&            a,
  37             const RangeType&            b )
  38         {
  39             o_rRanges.clear();
  40
  41             // special-casing the empty rect case (this will fail most
  42             // of the times below, because of the DBL_MIN/MAX special
  43             // values denoting emptiness in the rectangle.
  44             if( a.isEmpty() )
  45             {
  46                 o_rRanges.push_back( b );
  47                 return;
  48             }
  49             if( b.isEmpty() )
  50             {
  51                 o_rRanges.push_back( a );
  52                 return;
  53             }
  54
  55             const typename RangeType::ValueType                     ax(a.getMinX());
  56             const typename RangeType::ValueType                     ay(a.getMinY());
  57             const typename RangeType::TraitsType::DifferenceType    aw(a.getWidth());
  58             const typename RangeType::TraitsType::DifferenceType    ah(a.getHeight());
  59             const typename RangeType::ValueType                     bx(b.getMinX());
  60             const typename RangeType::ValueType                     by(b.getMinY());
  61             const typename RangeType::TraitsType::DifferenceType    bw(b.getWidth());
  62             const typename RangeType::TraitsType::DifferenceType    bh(b.getHeight());
  63
  64             const typename RangeType::TraitsType::DifferenceType    h0( (by > ay) ? by - ay : 0 );
  65             const typename RangeType::TraitsType::DifferenceType    h3( (by + bh < ay + ah) ? ay + ah - by - bh : 0 );
  66             const typename RangeType::TraitsType::DifferenceType    w1( (bx > ax) ? bx - ax : 0 );
  67             const typename RangeType::TraitsType::DifferenceType    w2( (ax + aw > bx + bw) ? ax + aw - bx - bw : 0 );
  68             const typename RangeType::TraitsType::DifferenceType    h12( (h0 + h3 < ah) ? ah - h0 - h3 : 0 );
  69
  70             // TODO(E2): Use numeric_cast instead of static_cast here,
  71             // need range checks!
  72             if (h0 > 0)
  73                 o_rRanges.push_back(
  74                     RangeType(ax,ay,
  75                               static_cast<typename RangeType::ValueType>(ax+aw),
  76                               static_cast<typename RangeType::ValueType>(ay+h0)) );
  77
  78             if (w1 > 0 && h12 > 0)
  79                 o_rRanges.push_back(
  80                     RangeType(ax,
  81                               static_cast<typename RangeType::ValueType>(ay+h0),
  82                               static_cast<typename RangeType::ValueType>(ax+w1),
  83                               static_cast<typename RangeType::ValueType>(ay+h0+h12)) );
  84
  85             if (w2 > 0 && h12 > 0)
  86                 o_rRanges.push_back(
  87                     RangeType(static_cast<typename RangeType::ValueType>(bx+bw),
  88                               static_cast<typename RangeType::ValueType>(ay+h0),
  89                               static_cast<typename RangeType::ValueType>(bx+bw+w2),
  90                               static_cast<typename RangeType::ValueType>(ay+h0+h12)) );
  91
  92             if (h3 > 0)
  93                 o_rRanges.push_back(
  94                     RangeType(ax,
  95                               static_cast<typename RangeType::ValueType>(ay+h0+h12),
  96                               static_cast<typename RangeType::ValueType>(ax+aw),
  97                               static_cast<typename RangeType::ValueType>(ay+h0+h12+h3)) );
  98         }
  99     }
 100
 101     ::std::vector< B2IRange >& computeSetDifference( ::std::vector< B2IRange >& o_rResult,
 102                                                      const B2IRange&            rFirst,
 103                                                      const B2IRange&            rSecond )
 104     {
 105         doComputeSetDifference( o_rResult, rFirst, rSecond );
 106
 107         return o_rResult;
 108     }
 109
 110     ::std::vector< B2DRange >& computeSetDifference( ::std::vector< B2DRange >& o_rResult,
 111                                                      const B2DRange&            rFirst,
 112                                                      const B2DRange&            rSecond )
 113     {
 114         doComputeSetDifference( o_rResult, rFirst, rSecond );
 115
 116         return o_rResult;
 117     }
 118
 119 } // end of namespace basegfx
 120
 121 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */