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