kc3-lang/ftgl/src/FTGlyph/FTTriangleExtractorGlyph.cpp

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• Author : Richard Ulrich
  Date : 2012-06-13 21:27:56
  Hash : d7d4594e
  Message : added polygon extraction

• src/FTGlyph/FTTriangleExtractorGlyph.cpp

• /*
   * FTGL - OpenGL font library
   *
   * Copyright (c) 2011 Richard Ulrich <richi@paraeasy.ch>
   *
   * 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.
   */
  
  #include "config.h"
  
  #include "FTGL/ftgl.h"
  
  #include "FTInternals.h"
  #include "FTTriangleExtractorGlyphImpl.h"
  #include "FTVectoriser.h"
  // std lib
  #include <cassert>
  
  //
  //  FTGLTriangleExtractorGlyph
  //
  
  
  FTTriangleExtractorGlyph::FTTriangleExtractorGlyph(FT_GlyphSlot glyph, float outset,
                                 std::vector<float>& triangles) :
      FTGlyph(new FTTriangleExtractorGlyphImpl(glyph, outset, triangles))
  {}
  
  
  FTTriangleExtractorGlyph::~FTTriangleExtractorGlyph()
  {}
  
  
  const FTPoint& FTTriangleExtractorGlyph::Render(const FTPoint& pen, int renderMode)
  {
      FTTriangleExtractorGlyphImpl *myimpl = dynamic_cast<FTTriangleExtractorGlyphImpl *>(impl);
      return myimpl->RenderImpl(pen, renderMode);
  }
  
  
  //
  //  FTGLTriangleExtractorGlyphImpl
  //
  
  
  FTTriangleExtractorGlyphImpl::FTTriangleExtractorGlyphImpl(FT_GlyphSlot glyph, float _outset,
                                         std::vector<float>& triangles)
  :   FTGlyphImpl(glyph),
      triangles_(triangles)
  {
      if(ft_glyph_format_outline != glyph->format)
      {
          err = 0x14; // Invalid_Outline
          return;
      }
  
      vectoriser = new FTVectoriser(glyph);
  
      if((vectoriser->ContourCount() < 1) || (vectoriser->PointCount() < 3))
      {
          delete vectoriser;
          vectoriser = NULL;
          return;
      }
  
  
      hscale = glyph->face->size->metrics.x_ppem * 64;
      vscale = glyph->face->size->metrics.y_ppem * 64;
      outset = _outset;
  }
  
  
  FTTriangleExtractorGlyphImpl::~FTTriangleExtractorGlyphImpl()
  {
      delete vectoriser;
  }
  
  
  const FTPoint& FTTriangleExtractorGlyphImpl::RenderImpl(const FTPoint& pen,
                                                int renderMode)
  {
      (void)renderMode;
  
  	if(NULL == vectoriser)
  		return advance;
  
      vectoriser->MakeMesh(1.0, 1, outset);
      const FTMesh *mesh = vectoriser->GetMesh();
  
      for(unsigned int t = 0; t < mesh->TesselationCount(); ++t)
      {
          const FTTesselation* subMesh = mesh->Tesselation(t);
          const unsigned int polygonType = subMesh->PolygonType();
  
          // convert everything to a single triangle strip.
          // In some cases we have to insert invalid triangles to make a valid strip
          switch(polygonType)
          {
              case GL_TRIANGLE_STRIP:
                  AddVertex(pen, subMesh->Point(0));
                  for(unsigned int i = 0; i < subMesh->PointCount(); ++i)
                      AddVertex(pen, subMesh->Point(i));
                  AddVertex(pen, subMesh->Point(subMesh->PointCount() - 1));
                  break;
              case GL_TRIANGLES:
                  assert(subMesh->PointCount() % 3 == 0);
                  for(unsigned int i = 0; i < subMesh->PointCount(); i += 3)
                  {
                      AddVertex(pen, subMesh->Point(i));
                      AddVertex(pen, subMesh->Point(i));
                      AddVertex(pen, subMesh->Point(i+1));
                      AddVertex(pen, subMesh->Point(i+2));
                      AddVertex(pen, subMesh->Point(i+2));
                  }
                  break;
              case GL_TRIANGLE_FAN:
              {
                  const FTPoint& centerPoint = subMesh->Point(0);
                  AddVertex(pen, centerPoint);
  
                  for(unsigned int i = 1; i < subMesh->PointCount()-1; ++i)
                  {
                      AddVertex(pen, centerPoint);
                      AddVertex(pen, subMesh->Point(i));
                      AddVertex(pen, subMesh->Point(i+1));
                      AddVertex(pen, centerPoint);
                  }
                  AddVertex(pen, centerPoint);
                  break;
              }
              default:
                  assert(!"please implement...");
              ;
          }
  
  
      }
  
      return advance;
  }
  
  void FTTriangleExtractorGlyphImpl::AddVertex(const FTPoint& pen, const FTPoint& point)
  {
      triangles_.push_back(pen.Xf() + point.Xf() / 64.0);
      triangles_.push_back(pen.Yf() + point.Yf() / 64.0);
      triangles_.push_back(pen.Zf());
  }