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kc3-lang/ftgl/src/FTVectoriser.cpp

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  • Author : sammy
    Date : 2008-04-21 21:48:03
    Hash : 7e74380f
    Message : * Inset/outset contour support for fonts, by Eric Beets. For now, only contours with exactly the same number of points are generated.

  • src/FTVectoriser.cpp
  • /*
     * FTGL - OpenGL font library
     *
     * Copyright (c) 2001-2004 Henry Maddocks <ftgl@opengl.geek.nz>
     *               2008 Éric Beets <ericbeets@free.fr>
     *
     * 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 "FTVectoriser.h"
    #include "FTGL.h"
    
    #ifndef CALLBACK
    #define CALLBACK
    #endif
    
    #ifdef __APPLE_CC__    
        typedef GLvoid (*GLUTesselatorFunction)(...);
    #elif defined( __mips ) || defined( __linux__ ) || defined( __FreeBSD__ ) || defined( __OpenBSD__ ) || defined( __sun ) || defined (__CYGWIN__)
        typedef GLvoid (*GLUTesselatorFunction)();
    #elif defined ( WIN32)
        typedef GLvoid (CALLBACK *GLUTesselatorFunction)( );
    #else
        #error "Error - need to define type GLUTesselatorFunction for this platform/compiler"
    #endif
    
    
    void CALLBACK ftglError( GLenum errCode, FTMesh* mesh)
    {
        mesh->Error( errCode);
    }
    
    
    void CALLBACK ftglVertex( void* data, FTMesh* mesh)
    {
        FTGL_DOUBLE* vertex = static_cast<FTGL_DOUBLE*>(data);
        mesh->AddPoint( vertex[0], vertex[1], vertex[2]);
    }
    
    
    void CALLBACK ftglCombine( FTGL_DOUBLE coords[3], void* vertex_data[4], GLfloat weight[4], void** outData, FTMesh* mesh)
    {
        const FTGL_DOUBLE* vertex = static_cast<const FTGL_DOUBLE*>(coords);
        *outData = const_cast<FTGL_DOUBLE*>(mesh->Combine( vertex[0], vertex[1], vertex[2]));
    }
            
    
    void CALLBACK ftglBegin( GLenum type, FTMesh* mesh)
    {
        mesh->Begin( type);
    }
    
    
    void CALLBACK ftglEnd( FTMesh* mesh)
    {
        mesh->End();
    }
    
    
    FTMesh::FTMesh()
    :	currentTesselation(0),
        err(0)
    {
        tesselationList.reserve( 16);
    }
    
    
    FTMesh::~FTMesh()
    {
        for( size_t t = 0; t < tesselationList.size(); ++t)
        {
            delete tesselationList[t];
        }
        
        tesselationList.clear();
    }
    
    
    void FTMesh::AddPoint( const FTGL_DOUBLE x, const FTGL_DOUBLE y, const FTGL_DOUBLE z)
    {
        currentTesselation->AddPoint( x, y, z);
    }
    
    
    const FTGL_DOUBLE* FTMesh::Combine( const FTGL_DOUBLE x, const FTGL_DOUBLE y, const FTGL_DOUBLE z)
    {
        tempPointList.push_back( FTPoint( x, y,z));
        return static_cast<const FTGL_DOUBLE*>(tempPointList.back());
    }
    
    
    void FTMesh::Begin( GLenum meshType)
    {
        currentTesselation = new FTTesselation( meshType);
    }
    
    
    void FTMesh::End()
    {
        tesselationList.push_back( currentTesselation);
    }
    
    
    const FTTesselation* const FTMesh::Tesselation( unsigned int index) const
    {
        return ( index < tesselationList.size()) ? tesselationList[index] : NULL;
    }
    
    
    FTVectoriser::FTVectoriser(const FT_GlyphSlot glyph, float frontOutset, float backOutset)
    :   contourList(0),
        mesh(0),
        ftContourCount(0),
        contourFlag(0)
    {
        if( glyph)
        {
            outline = glyph->outline;
            
            ftContourCount = outline.n_contours;
            contourList = 0;
            contourFlag = outline.flags;
            
            ProcessContours(frontOutset, backOutset);
        }
    }
    
    
    FTVectoriser::~FTVectoriser()
    {
        for( size_t c = 0; c < ContourCount(); ++c)
        {
            delete contourList[c];
        }
    
        delete [] contourList;
        delete mesh;
    }
    
    
    void FTVectoriser::ProcessContours(float frontOutset, float backOutset)
    {
        short contourLength = 0;
        short startIndex = 0;
        short endIndex = 0;
        
        contourList = new FTContour*[ftContourCount];
        
        for( short contourIndex = 0; contourIndex < ftContourCount; ++contourIndex)
        {
            FT_Vector* pointList = &outline.points[startIndex];
            char* tagList = &outline.tags[startIndex];
            
            endIndex = outline.contours[contourIndex];
            contourLength =  ( endIndex - startIndex) + 1;
    
            FTContour* contour = new FTContour(pointList, tagList, contourLength, frontOutset, backOutset);
            
            contourList[contourIndex] = contour;
            
            startIndex = endIndex + 1;
        }
    }
    
    
    size_t FTVectoriser::PointCount()
    {
        size_t s = 0;
        for( size_t c = 0; c < ContourCount(); ++c)
        {
            s += contourList[c]->PointCount();
        }
        
        return s;
    }
    
    
    const FTContour* const FTVectoriser::Contour( unsigned int index) const
    {
        return ( index < ContourCount()) ? contourList[index] : NULL;
    }
    
    
    void FTVectoriser::MakeMesh(FTGL_DOUBLE zNormal, int outsetContour)
    {
        if( mesh)
        {
            delete mesh;
        }
            
        mesh = new FTMesh;
        
        GLUtesselator* tobj = gluNewTess();
    
        gluTessCallback( tobj, GLU_TESS_BEGIN_DATA,     (GLUTesselatorFunction)ftglBegin);
        gluTessCallback( tobj, GLU_TESS_VERTEX_DATA,    (GLUTesselatorFunction)ftglVertex);
        gluTessCallback( tobj, GLU_TESS_COMBINE_DATA,   (GLUTesselatorFunction)ftglCombine);
        gluTessCallback( tobj, GLU_TESS_END_DATA,       (GLUTesselatorFunction)ftglEnd);
        gluTessCallback( tobj, GLU_TESS_ERROR_DATA,     (GLUTesselatorFunction)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, 0.0f, 0.0f, zNormal);
        gluTessBeginPolygon( tobj, mesh);
    
            for( size_t c = 0; c < ContourCount(); ++c)
            {
                const FTContour* contour = contourList[c];
    
                gluTessBeginContour( tobj);
                    for( size_t p = 0; p < contour->PointCount(); ++p)
                    {
                        const FTGL_DOUBLE* d;
                        switch(outsetContour)
                        {
                            case 0: d = contour->Point(p); break;
                            case 1 : d = contour->FrontPoint(p); break;
                            case 2 : d = contour->BackPoint(p);  break;
                        }
                        gluTessVertex( tobj, (GLdouble*)d, (GLdouble*)d);
                    }
    
                gluTessEndContour( tobj);
            }
        gluTessEndPolygon( tobj);
    
        gluDeleteTess( tobj);
    }