kc3-lang/ftgl/src/FTExtrdGlyph.cpp

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• Hash : ccddd5df
  Author :
  Date : 2001-11-29T05:10:21
  

  Added Winding fuction to colc area for a full contour rather than part of one

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• src/FTExtrdGlyph.cpp

• #ifdef FTGL_DEBUG
  	#include "mmgr.h"
  #endif
  
  #include	"FTExtrdGlyph.h"
  #include	"FTVectoriser.h"
  
  
  FTExtrdGlyph::FTExtrdGlyph( FT_Glyph glyph, float d)
  :	FTGlyph(),
  	vectoriser(0),
  	numPoints(0),
  	frontMesh(0),
  	backMesh(0),
  	sidemesh(0),
  	glList(0),
  	depth(d)
  {
  	if( ft_glyph_format_outline != glyph->format)
  	{
  		return;
  	}
  
  	vectoriser = new FTVectoriser( glyph);
  	
  	vectoriser->Process();
  
  	// Make the front polygons
  	vectoriser->MakeMesh( 1.0);
  	
  	bBox = FTBBox( glyph);
  	bBox.z2 = -depth;
  	advance = glyph->advance.x >> 16;
  	
  	numPoints = vectoriser->MeshPoints();
  	if ( numPoints < 3)
  	{
  		delete vectoriser;
  		return;
  	}
  	
  	frontMesh = new double[ numPoints * 3];
  	vectoriser->GetMesh( frontMesh);
  	
  	// Make the back polygons
  	vectoriser->MakeMesh( -1.0);
  	
  	numPoints = vectoriser->MeshPoints();
  	if ( numPoints < 3)
  	{
  		delete vectoriser;
  		delete [] frontMesh;
  		return;
  	}
  	
  	backMesh =  new double[ numPoints * 3];
  	vectoriser->GetMesh( backMesh);
  	
  	numPoints = vectoriser->points();
  	int numContours = vectoriser->contours(); // FIXME
  	
  	if ( ( numContours < 1) || ( numPoints < 3))
  	{
  		delete vectoriser;
  		delete [] frontMesh;
  		delete [] backMesh;
  		return;
  	}
  	
  	// Build the edge polygons
  	int* contourLength = new int[ numContours];
  	for( int cn = 0; cn < numContours; ++cn)
  	{
  		contourLength[cn] = vectoriser->contourSize( cn);
  	}
  	
  	sidemesh = new double[ numPoints * 3];
  	vectoriser->GetOutline( sidemesh);
  	
  	delete vectoriser;
  	
  	// Draw the glyph
  	int offset = 0;
  	glList = glGenLists(1);
  	glNewList( glList, GL_COMPILE);
  		// Render Front Mesh
  		int BEPairs = static_cast<int>(frontMesh[0]);
  		for( int i = 0; i < BEPairs; ++i)
  		{
  			int polyType = (int)frontMesh[offset + 1];
  			glBegin( polyType);
  				glNormal3d(0.0, 0.0, 1.0);
  		
  				int verts = (int)frontMesh[offset+2];
  				offset += 3;
  				for( int x = 0; x < verts; ++x)
  				{
  					glVertex3dv( frontMesh + offset);
  					offset += 3;
  				}
  			glEnd();
  		}
  		
  		// Render Back Mesh
  		offset = 0;
  		BEPairs = static_cast<int>(backMesh[0]);
  		for( int i = 0; i < BEPairs; ++i)
  		{
  			int polyType = (int)backMesh[offset + 1];
  			glBegin( polyType);
  
  				glNormal3d(0.0, 0.0, -1.0);
  				int verts = (int)backMesh[offset+2];
  				offset += 3;
  				for( int x = 0; x < verts; ++x)
  				{
  					glVertex3d( backMesh[offset], backMesh[offset + 1], -depth); // FIXME
  					offset += 3;
  				}
  			glEnd();
  		}
  		
  		FT_OutlineGlyph outline = (FT_OutlineGlyph)glyph;
  		FT_Outline ftOutline = outline->outline;
  		int contourFlag = ftOutline.flags; // this is broken for winding direction in freetype so...
  
  		// This assumes that the first contour is an outside contour!!!
  		bool winding = Winding( contourLength[0], sidemesh);
  			
  		// Join them together.
  		// Extrude each contour to make the sides.
  		double* contour = sidemesh;
  		for (int c=0; c<numContours; ++c)
  		{
  			// Make a quad strip using each successive
  			// pair of points in this contour.
  			int numPoints = contourLength[c];
  			
  			glBegin( GL_QUAD_STRIP);
  
  				for( int j= 0; j <= numPoints; ++j)
  				{
  					int j1 = (j < numPoints) ? j : 0;
  					int j0 = (j1 == 0) ? (numPoints-1) : (j1-1);
  
  					double* p0 = contour + j0*3;
  					double* p1 = contour + j1*3;
  
  					// Compute normal for this quad.
  					double vx = p1[0] - p0[0];
  					double vy = p1[1] - p0[1];
  					// Normalise
  					double length = sqrt( ( ( vx * vx) + ( vy * vy)));
  					vx /= length; vy /= length;
  					glNormal3d(-vy, vx, 0.0);
  					
  					// Add vertices to the quad strip.
  					// Winding order
  //					if( contourFlag & ft_outline_reverse_fill) // this is broken in freetype so...
  					if( winding)
  					{
  						glVertex3d(p0[0], p0[1], 0);
  						glVertex3d(p0[0], p0[1], -depth);
  					}
  					else
  					{
  						glVertex3d(p0[0], p0[1], -depth);
  						glVertex3d(p0[0], p0[1], 0);
  					}
  				} // for
  			glEnd();
  			contour += numPoints*3;
  		} // for 
  		
  		
  	glEndList();
  
  	delete [] sidemesh; // FIXME
  	delete [] frontMesh;
  	delete [] backMesh;
  	delete [] contourLength;
  
  	// discard glyph image (bitmap or not)
  	FT_Done_Glyph( glyph); // Why does this have to be HERE
  }
  
  
  FTExtrdGlyph::~FTExtrdGlyph()
  {
  //	if( data)
  //		delete [] data; // FIXME
  }
  
  
  bool FTExtrdGlyph::Winding( int numPoints, double *points)
  {
  	// Calculate the winding direction. use formula from redbook.
  	double area = 0;
  	
  	for( int count= 0; count <= numPoints; ++count)
  	{
  		int j1 = (count < numPoints) ? count : 0;
  		int j0 = (j1 == 0) ? ( numPoints-1) : ( j1-1);
  
  		double* p0 = points + j0 * 3;
  		double* p1 = points + j1 * 3;
  
  		area += ( p0[0] * p1[1]) - ( p1[0] * p0[1]);	
  	}
  	
  	return( area < 0 ? false: true);
  }
  
  float FTExtrdGlyph::Render( const FT_Vector& pen)
  {
  	if( glList)
  	{
  		glTranslatef( pen.x, pen.y, 0);
  			glCallList( glList);	
  		glTranslatef( -pen.x, -pen.y, 0);
  	}
  	
  	return advance;
  }
  

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