basegfx/source/curve/b2dbeziertools.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  *
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  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/curve/b2dbeziertools.hxx>
  21 #include <basegfx/curve/b2dcubicbezier.hxx>
  22 #include <algorithm>
  23
  24 //////////////////////////////////////////////////////////////////////////////
  25
  26 namespace basegfx
  27 {
  28     B2DCubicBezierHelper::B2DCubicBezierHelper(const B2DCubicBezier& rBase, sal_uInt32 nDivisions)
  29     :   maLengthArray(),
  30         mnEdgeCount(0)
  31     {
  32         const bool bIsBezier(rBase.isBezier());
  33
  34         if(bIsBezier)
  35         {
  36             // check nDivisions; at least one is needed, but also prevent too big values
  37             if(nDivisions < 1)
  38             {
  39                 nDivisions = 1;
  40             }
  41             else if(nDivisions > 1000)
  42             {
  43                 nDivisions = 1000;
  44             }
  45
  46             // set nEdgeCount
  47             mnEdgeCount = nDivisions + 1;
  48
  49             // fill in maLengthArray
  50             maLengthArray.clear();
  51             maLengthArray.reserve(mnEdgeCount);
  52             B2DPoint aCurrent(rBase.getStartPoint());
  53             double fLength(0.0);
  54
  55             for(sal_uInt32 a(1);;)
  56             {
  57                 const B2DPoint aNext(rBase.interpolatePoint((double)a / (double)mnEdgeCount));
  58                 const B2DVector aEdge(aNext - aCurrent);
  59
  60                 fLength += aEdge.getLength();
  61                 maLengthArray.push_back(fLength);
  62
  63                 if(++a < mnEdgeCount)
  64                 {
  65                     aCurrent = aNext;
  66                 }
  67                 else
  68                 {
  69                     const B2DPoint aLastNext(rBase.getEndPoint());
  70                     const B2DVector aLastEdge(aLastNext - aNext);
  71
  72                     fLength += aLastEdge.getLength();
  73                     maLengthArray.push_back(fLength);
  74                     break;
  75                 }
  76             }
  77         }
  78         else
  79         {
  80             maLengthArray.clear();
  81             maLengthArray.push_back(rBase.getEdgeLength());
  82             mnEdgeCount = 1;
  83         }
  84     }
  85
  86     double B2DCubicBezierHelper::distanceToRelative(double fDistance) const
  87     {
  88         if(fDistance <= 0.0)
  89         {
  90             return 0.0;
  91         }
  92
  93         const double fLength(getLength());
  94
  95         if(fTools::moreOrEqual(fDistance, fLength))
  96         {
  97             return 1.0;
  98         }
  99
 100         // fDistance is in ]0.0 .. fLength[
 101
 102         if(1 == mnEdgeCount)
 103         {
 104             // not a bezier, linear edge
 105             return fDistance / fLength;
 106         }
 107
 108         // it is a bezier
 109         ::std::vector< double >::const_iterator aIter = ::std::lower_bound(maLengthArray.begin(), maLengthArray.end(), fDistance);
 110         const sal_uInt32 nIndex(aIter - maLengthArray.begin());
 111         const double fHighBound(maLengthArray[nIndex]);
 112         const double fLowBound(nIndex ?  maLengthArray[nIndex - 1] : 0.0);
 113         const double fLinearInterpolatedLength((fDistance - fLowBound) / (fHighBound - fLowBound));
 114
 115         return (static_cast< double >(nIndex) + fLinearInterpolatedLength) / static_cast< double >(mnEdgeCount);
 116     }
 117
 118 } // end of namespace basegfx
 119
 120 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */