FTVectoriser.cpp

#include  "FTVectoriser.h"
#include  "FTGL.h"
#ifdef FTGL_DEBUG
  #include "mmgr.h"
#endif


#ifndef CALLBACK
#define CALLBACK
#endif

extern "C" {

typedef void (CALLBACK*ftglCallback)();

void CALLBACK ftglError( GLenum errCode, FTMesh* mesh)
{
  mesh->Error( errCode);
}

void CALLBACK ftglVertex( void* data, FTMesh* mesh)
{
  FTGL_DOUBLE* vertex = (FTGL_DOUBLE*)data;
  mesh->AddPoint( vertex[0], vertex[1], vertex[2]);
}


void CALLBACK ftglBegin( GLenum type, FTMesh* mesh)
{
  mesh->Begin( type);
}


void CALLBACK ftglEnd( FTMesh* mesh)
{
  mesh->End();
}


void CALLBACK ftglCombine( FTGL_DOUBLE coords[3], void* , GLfloat*, void** outData, FTMesh* mesh)
{
  FTGL_DOUBLE* vertex = (FTGL_DOUBLE*)coords;
  mesh->tempPool.push_back( ftPoint( vertex[0], vertex[1], vertex[2]));
  
  *outData = &mesh->tempPool[ mesh->tempPool.size() - 1].x;
}

} // End of extern C

#ifdef FTGL_USE_NAMESPACE
namespace ftgl
{
#endif

//=============================================================================

bool operator == ( const ftPoint &a, const ftPoint &b) 
{
  return((a.x == b.x) && (a.y == b.y) && (a.z == b.z));
}

bool operator != ( const ftPoint &a, const ftPoint &b) 
{
  return((a.x != b.x) || (a.y != b.y) || (a.z != b.z));
}
    

FTMesh::FTMesh()
:  err(0)
{
  tess.reserve( 16);
  tempPool.reserve( 128);
}


FTMesh::~FTMesh()
{
  for( size_t t = 0; t < tess.size(); ++t)
  {
    delete tess[t];
  }
  tess.clear();

  tempPool.clear();
}


void FTMesh::AddPoint( const FTGL_DOUBLE x, const FTGL_DOUBLE y, const FTGL_DOUBLE z)
{
  tempTess->AddPoint( x, y, z);
}

void FTMesh::Begin( GLenum m)
{
  tempTess = new FTTesselation;
  tempTess->meshType = m;
}


void FTMesh::End()
{
  tess.push_back( tempTess);
}


FTGL_DOUBLE* FTMesh::Point()
{
  return &tempTess->pointList[ tempTess->size() - 1].x;

}


int FTMesh::size() const
{
  int s = 0;
  for( size_t t = 0; t < tess.size(); ++t)
  {
    s += tess[t]->size();
    ++s;
  }
  return s;
}


//=============================================================================


FTVectoriser::FTVectoriser( const FT_Glyph glyph)
:  contour(0),
  mesh(0),
  contourFlag(0),
  kBSTEPSIZE( 0.2f)
{
  FT_OutlineGlyph outline = (FT_OutlineGlyph)glyph;
  ftOutline = outline->outline;
  
  contourList.reserve( ftOutline.n_contours);
}


FTVectoriser::~FTVectoriser()
{
  for( size_t c = 0; c < contours(); ++c)
  {
    delete contourList[c];
  }

  contourList.clear();
  
  if( mesh)
    delete mesh;
}


int FTVectoriser::points()
{
  int s = 0;
  for( size_t c = 0; c < contours(); ++c)
  {
    s += contourList[c]->size();
  }
  
  return s;
}


bool FTVectoriser::Process()
{
  short first = 0;
  short last;
  const short cont = ftOutline.n_contours;
  
  for( short c = 0; c < cont; ++c)
  {
    contour = new FTContour;
    contourFlag = ftOutline.flags;
    last = ftOutline.contours[c];

    for( int p = first; p <= last; ++p)
    {
      switch( ftOutline.tags[p])
      {
        case FT_Curve_Tag_Conic:
          p += Conic( p, first, last);
          break;
        case FT_Curve_Tag_Cubic:
          p += Cubic( p, first, last);
          break;
        case FT_Curve_Tag_On:
        default:
           contour->AddPoint( ftOutline.points[p].x, ftOutline.points[p].y);
      }
    }
    
    contourList.push_back( contour);
    first = (short)(last + 1);
  }
  
  return true;
}


int FTVectoriser::Conic( const int index, const int first, const int last)
{
  int next = index + 1;
  int prev = index - 1;
  
  if( index == last)
    next = first; 
  
  if( index == first)
    prev = last; 
  
  if( ftOutline.tags[next] != FT_Curve_Tag_Conic)
  {
    ctrlPtArray[0][0] = (float)ftOutline.points[prev].x;  
    ctrlPtArray[0][1] = (float)ftOutline.points[prev].y;
    ctrlPtArray[1][0] = (float)ftOutline.points[index].x;  
    ctrlPtArray[1][1] = (float)ftOutline.points[index].y;
    ctrlPtArray[2][0] = (float)ftOutline.points[next].x;  
    ctrlPtArray[2][1] = (float)ftOutline.points[next].y;
    
    evaluateCurve( 2);
    return 1;
  }
  else
  {
    int next2 = next + 1;
    if( next == last)
      next2 = first;
    
    //create a phantom point
    float x = (float)(ftOutline.points[index].x + ftOutline.points[next].x)/ 2;
    float y = (float)(ftOutline.points[index].y + ftOutline.points[next].y)/ 2;
    
    // process first curve
    ctrlPtArray[0][0] = (float)ftOutline.points[prev].x;  
    ctrlPtArray[0][1] = (float)ftOutline.points[prev].y;
    ctrlPtArray[1][0] = (float)ftOutline.points[index].x;  
    ctrlPtArray[1][1] = (float)ftOutline.points[index].y;
    ctrlPtArray[2][0] = (float)x;              
    ctrlPtArray[2][1] = (float)y;
    
    evaluateCurve( 2);
    
    // process second curve
    ctrlPtArray[0][0] = (float)x;              
    ctrlPtArray[0][1] = (float)y;
    ctrlPtArray[1][0] = (float)ftOutline.points[next].x;  
    ctrlPtArray[1][1] = (float)ftOutline.points[next].y;
    ctrlPtArray[2][0] = (float)ftOutline.points[next2].x;  
    ctrlPtArray[2][1] = (float)ftOutline.points[next2].y;
    evaluateCurve( 2);
    
    return 2;
  }
}


int FTVectoriser::Cubic( const int index, const int first, const int last)
{
  int next = index + 1;
  int prev = index - 1;
  
  if( index == last)
    next = first; 
  
  int next2 = next + 1;
  
  if( next == last)
    next2 = first;
  
  if( index == first)
    prev = last; 

  ctrlPtArray[0][0] = (float)ftOutline.points[prev].x;    
  ctrlPtArray[0][1] = (float)ftOutline.points[prev].y;
  ctrlPtArray[1][0] = (float)ftOutline.points[index].x;    
  ctrlPtArray[1][1] = (float)ftOutline.points[index].y;
  ctrlPtArray[2][0] = (float)ftOutline.points[next].x;    
  ctrlPtArray[2][1] = (float)ftOutline.points[next].y;
  ctrlPtArray[3][0] = (float)ftOutline.points[next2].x;    
  ctrlPtArray[3][1] = (float)ftOutline.points[next2].y;

  evaluateCurve( 3);
  return 2;
}


// De Casteljau algorithm contributed by Jed Soane
void FTVectoriser::deCasteljau( const float t, const int n)
{
    //Calculating successive b(i)'s using de Casteljau algorithm.
    for( int i = 1; i <= n; i++)
        for( int k = 0; k <= (n - i); k++)
        {
      bValues[i][k][0] = (1 - t) * bValues[i - 1][k][0] + t * bValues[i - 1][k + 1][0];
      bValues[i][k][1] = (1 - t) * bValues[i - 1][k][1] + t * bValues[i - 1][k + 1][1];
    }
    
    //Specify next vertex to be included on curve
  contour->AddPoint( bValues[n][0][0], bValues[n][0][1]);
}


// De Casteljau algorithm contributed by Jed Soane
void FTVectoriser::evaluateCurve( const int n)
{
    // setting the b(0) equal to the control points
    for( int i = 0; i <= n; i++)
  {
    bValues[0][i][0] = ctrlPtArray[i][0];
    bValues[0][i][1] = ctrlPtArray[i][1];
    }

    float t;                      //parameter for curve point calc. [0.0, 1.0]

    for( int m = 0; m <= ( 1 / kBSTEPSIZE); m++)
    {
      t = m * kBSTEPSIZE;
        deCasteljau( t, n);  //calls to evaluate point on curve att.
    }
}


void FTVectoriser::GetOutline( FTGL_DOUBLE* data)
{
  int i = 0;
  
  for( size_t c= 0; c < contours(); ++c)
  {
    const FTContour* acontour = contourList[c];
    
    for( size_t p = 0; p < acontour->size(); ++p)
    {
      data[i] = static_cast<FTGL_DOUBLE>(acontour->pointList[p].x / 64.0f); // is 64 correct?
      data[i + 1] = static_cast<FTGL_DOUBLE>(acontour->pointList[p].y / 64.0f);
      data[i + 2] = 0.0; // static_cast<FTGL_DOUBLE>(acontour->pointList[p].z / 64.0f);
      i += 3;
    }
  }
}


void FTVectoriser::MakeMesh( FTGL_DOUBLE zNormal)
{
  if( mesh)
  {
    delete mesh;
  }
    
  mesh = new FTMesh;
  
  GLUtesselator* tobj = gluNewTess();
  
  gluTessCallback( tobj, GLU_TESS_BEGIN_DATA,    (ftglCallback)ftglBegin);
  gluTessCallback( tobj, GLU_TESS_VERTEX_DATA,  (ftglCallback)ftglVertex);
  gluTessCallback( tobj, GLU_TESS_COMBINE_DATA,  (ftglCallback)ftglCombine);
  gluTessCallback( tobj, GLU_TESS_END_DATA,    (ftglCallback)ftglEnd);
  gluTessCallback( tobj, GLU_TESS_ERROR_DATA,    (ftglCallback)ftglError);
  
  
  if( contourFlag & ft_outline_even_odd_fill) // ft_outline_reverse_fill
  {
    gluTessProperty( tobj, GLU_TESS_WINDING_RULE, GLU_TESS_WINDING_ODD);
  }
  else
  {
    gluTessProperty( tobj, GLU_TESS_WINDING_RULE, GLU_TESS_WINDING_NONZERO);
  }
  
  
  gluTessProperty( tobj, GLU_TESS_TOLERANCE, 0);
  gluTessNormal( tobj, 0.0, 0.0, zNormal);
  gluTessBeginPolygon( tobj, mesh);
  
    for( size_t c = 0; c < contours(); ++c)
    {
      const FTContour* acontour = contourList[c];
      gluTessBeginContour( tobj);
      
        for( size_t p = 0; p < acontour->size(); ++p)
        {
          FTGL_DOUBLE* d = const_cast<FTGL_DOUBLE*>(&acontour->pointList[p].x);
          gluTessVertex( tobj, d, d);
        }
      gluTessEndContour( tobj);
    }
    
  gluTessEndPolygon( tobj);

  gluDeleteTess( tobj);
  
}


void FTVectoriser::GetMesh( FTGL_DOUBLE* data)
{
   // Now write it out
  int i = 0;
  
  // fill out the header
  size_t msize = mesh->tess.size();
  data[0] = msize;
  
  for( int p = 0; p < data[0]; ++p)
  {
    FTTesselation* tess = mesh->tess[p];
    size_t tSize =  tess->pointList.size();
    int tType =  tess->meshType;
    
    data[i+1] = tType;
    data[i+2] = tSize;
    i += 3;
    for( size_t q = 0; q < ( tess->pointList.size()); ++q)
    {
      data[i] = tess->pointList[q].x / 64.0f; // is 64 correct?
      data[i + 1] = tess->pointList[q].y / 64.0f;
      data[i + 2] = 0.0; // static_cast<FTGL_DOUBLE>(mesh->pointList[p].z / 64.0f);
      i += 3;
    
    }

  }

}

#ifdef FTGL_USE_NAMESPACE
} // namespace ftgl
#endif