kc3-lang/ftgl/src/FTContour.cpp

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• Author : sammy
  Date : 2008-04-13 09:06:38
  Hash : eb169fd2
  Message : * Fix a crash in FTContour::FTContour caused by invalid or unknown tags.

• src/FTContour.cpp

• /*
   * FTGL - OpenGL font library
   *
   * Copyright (c) 2001-2004 Henry Maddocks <ftgl@opengl.geek.nz>
   *               2008 Sam Hocevar <sam@zoy.org>
   *
   * Permission is hereby granted, free of charge, to any person obtaining
   * a copy of this software and associated documentation files (the
   * "Software"), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sublicense, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   *
   * The above copyright notice and this permission notice shall be
   * included in all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
   * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
   * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
   * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
   * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   *
   * Alternatively, you can redistribute and/or modify this software under
   * the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License,
   * or (at your option) any later version.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this software; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA.
   */
  
  #include "config.h"
  
  #include "FTContour.h"
  
  static const float BEZIER_STEP_SIZE = 0.2f;
  
  
  void FTContour::AddPoint(FTPoint point)
  {
      if(pointList.empty() || point != pointList[pointList.size() - 1])
      {
          pointList.push_back(point);
      }
  }
  
  
  void FTContour::evaluateQuadraticCurve(FTPoint A, FTPoint B, FTPoint C)
  {
      for(unsigned int i = 0; i <= (1.0f / BEZIER_STEP_SIZE); i++)
      {
          float t = static_cast<float>(i) * BEZIER_STEP_SIZE;
  
          FTPoint U = (1.0f - t) * A + t * B;
          FTPoint V = (1.0f - t) * B + t * C;
  
          AddPoint((1.0f - t) * U + t * V);
      }
  }
  
  
  void FTContour::evaluateCubicCurve(FTPoint A, FTPoint B, FTPoint C, FTPoint D)
  {
      for(unsigned int i = 0; i <= (1.0f / BEZIER_STEP_SIZE); i++)
      {
          float t = static_cast<float>(i) * BEZIER_STEP_SIZE;
  
          FTPoint U = (1.0f - t) * A + t * B;
          FTPoint V = (1.0f - t) * B + t * C;
          FTPoint W = (1.0f - t) * C + t * D;
  
          FTPoint M = (1.0f - t) * U + t * V;
          FTPoint N = (1.0f - t) * V + t * W;
  
          AddPoint((1.0f - t) * M + t * N);
      }
  }
  
  
  FTContour::FTContour(FT_Vector* contour, char* tags, unsigned int n)
  {
      for(unsigned int i = 0; i < n; ++ i)
      {
          if(tags[i] == FT_Curve_Tag_On || n < 2)
          {
              AddPoint(FTPoint(contour[i]));
              continue;
          }
  
          FTPoint cur(contour[i]);
          FTPoint prev = (pointList.size() == 0 || i == 0)
                         ? FTPoint(contour[n - 1])
                         : pointList[pointList.size() - 1];
          FTPoint next = (i == n - 1)
                         ? (pointList.size() == 0)
                           ? FTPoint(contour[0])
                           : pointList[0]
                         : FTPoint(contour[i + 1]);
  
          if(tags[i] == FT_Curve_Tag_Conic)
          {
              while(tags[(i == n - 1) ? 0 : i + 1] == FT_Curve_Tag_Conic)
              {
                  next = (cur + next) * 0.5f;
  
                  evaluateQuadraticCurve(prev, cur, next);
                  ++i;
  
                  prev = next;
                  cur = FTPoint(contour[i]);
                  next = (i == n - 1)
                         ? pointList[0]
                         : FTPoint(contour[i + 1]);
              }
  
              evaluateQuadraticCurve(prev, cur, next);
              continue;
          }
  
          if(tags[i] == FT_Curve_Tag_Cubic)
          {
              FTPoint cur2 = next;
  
              FTPoint next = (i == n - 2)
                             ? pointList[0]
                             : FTPoint(contour[i + 2]);
  
              evaluateCubicCurve(prev, cur, cur2, next);
              ++i;
              continue;
          }
      }
  }