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