/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield * * This library is open source and may be redistributed and/or modified under * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or * (at your option) any later version. The full license is in LICENSE file * included with this distribution, and on the openscenegraph.org website. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * OpenSceneGraph Public License for more details. */ #ifndef OSGUTIL_Tessellator #define OSGUTIL_Tessellator #include #include #include #include #ifndef CALLBACK /* Win32 calling conventions. (or a least thats what the GLUT example tess.c uses.)*/ #define CALLBACK #endif namespace osgUtil { /** Originally a simple class for tessellating a single polygon boundary. * Using old style glu tessellation functions for portability. * Upgraded Jan 2004 to use the modern glu tessellation functions.*/ class OSGUTIL_EXPORT Tessellator : public osg::Referenced { public: Tessellator(); ~Tessellator(); /** The winding rule, see red book ch 11. */ enum WindingType{ TESS_WINDING_ODD = GLU_TESS_WINDING_ODD, TESS_WINDING_NONZERO = GLU_TESS_WINDING_NONZERO, TESS_WINDING_POSITIVE = GLU_TESS_WINDING_POSITIVE, TESS_WINDING_NEGATIVE = GLU_TESS_WINDING_NEGATIVE, TESS_WINDING_ABS_GEQ_TWO = GLU_TESS_WINDING_ABS_GEQ_TWO } ; /** we interpret all contours in the geometry as a single set to be tessellated or * each separate drawable's contours needs to be tessellated. */ enum TessellationType { TESS_TYPE_GEOMETRY, // tessellate everything in the geometry object TESS_TYPE_DRAWABLE, // tessellate each polygon, triangles & quads drawables in geometry separately TESS_TYPE_POLYGONS // tessellate ONLY polygon drawables in geometry separately }; /** Set and get tessellation request boundary only on/off */ void setBoundaryOnly (const bool tt) { _boundaryOnly=tt;} inline bool getBoundaryOnly ( ) { return _boundaryOnly;} /** Set and get tessellation windong rule */ void setWindingType (const WindingType wt) { _wtype=wt;} inline WindingType getWindingType ( ) { return _wtype;} /** Set and get tessellation type */ void setTessellationType (const TessellationType tt) { _ttype=tt;} inline TessellationType getTessellationType ( ) { return _ttype;} /** Change the contours lists of the geometry into tessellated primitives (the * list of primitives in the original geometry is stored in the Tessellator for * possible re-use. * The name remains retessellatePolygons although it now handles trifans, strips, quads etc. * as well as Polygons so as to not break old codes relying on this function name. */ void retessellatePolygons(osg::Geometry &cxgeom); /** Define the normal to the tessellated polygon - this provides a hint how to * tessellate the contours; see gluTessNormal in red book or man pages. * GWM July 2005. Can improve teselation * "For example, if you know that all polygons lie in the x-y plane, * call gluTessNormal(tess, 0.0, 0.0, 1.0) before rendering any polygons." */ void setTessellationNormal(const osg::Vec3 norm) { tessNormal=norm;} osg::Geometry::PrimitiveSetList getContours() { return _Contours;} struct Prim : public osg::Referenced { Prim(GLenum mode):_mode(mode) {} typedef std::vector VecList; GLenum _mode; VecList _vertices; }; virtual void beginTessellation(); void beginContour(); /** Add a vertex to the current contour, see gluTessVertex for details. * Note the vertex pointer is returned at the end of tessellation and * must not be left dangling or be overwritten until all results are * collected. */ void addVertex(osg::Vec3* vertex); void endContour(); void endTessellation(); typedef std::vector< osg::ref_ptr > PrimList; PrimList& getPrimList() { return _primList; } void reset(); protected: /** remove unused parts of the array, eg for when retessellating * tessellation can introduce extra vertices for concave or crossing boundaries, * these will leak memory if not removed when retessellating. */ void reduceArray(osg::Array * cold, const unsigned int nnu); void collectTessellation(osg::Geometry &cxgeom, unsigned int originalIndex); typedef std::map VertexPtrToIndexMap; void addContour(GLenum mode, unsigned int first, unsigned int last, osg::Vec3Array* vertices); void addContour(osg::PrimitiveSet* primitive, osg::Vec3Array* vertices); void handleNewVertices(osg::Geometry& geom,VertexPtrToIndexMap &vertexPtrToIndexMap); void begin(GLenum mode); void vertex(osg::Vec3* vertex); void combine(osg::Vec3* vertex,void* vertex_data[4],GLfloat weight[4]); void end(); void error(GLenum errorCode); static void CALLBACK beginCallback(GLenum which, void* userData); static void CALLBACK vertexCallback(GLvoid *data, void* userData); static void CALLBACK combineCallback(GLdouble coords[3], void* vertex_data[4], GLfloat weight[4], void** outData, void* useData); static void CALLBACK endCallback(void* userData); static void CALLBACK errorCallback(GLenum errorCode, void* userData); struct Vec3d { double _v[3]; }; struct NewVertex { NewVertex(): _vpos(0), _f1(0), _v1(0), _f2(0), _v2(0), _f3(0), _v3(0), _f4(0), _v4(0) {} NewVertex(const NewVertex& nv): _vpos(nv._vpos), _f1(nv._f1), _v1(nv._v1), _f2(nv._f2), _v2(nv._v2), _f3(nv._f3), _v3(nv._v3), _f4(nv._f4), _v4(nv._v4) {} NewVertex(osg::Vec3* vx, float f1,osg::Vec3* v1, float f2,osg::Vec3* v2, float f3,osg::Vec3* v3, float f4,osg::Vec3* v4): _vpos(vx), _f1(f1), _v1(v1), _f2(f2), _v2(v2), _f3(f3), _v3(v3), _f4(f4), _v4(v4) {} osg::Vec3 *_vpos; // added gwm Jan 2004 the vertex coords s.t. NewVertex can be used in a std::vector float _f1; osg::Vec3* _v1; float _f2; osg::Vec3* _v2; float _f3; osg::Vec3* _v3; float _f4; osg::Vec3* _v4; }; //change NewVertexList from std::map NewVertexList; // because this has undefined order of insertion for new vertices. // which occasionally corrupted the texture mapping. typedef std::vector NewVertexList; typedef std::vector Vec3dList; osg::GLUtesselator* _tobj; PrimList _primList; Vec3dList _coordData; NewVertexList _newVertexList; GLenum _errorCode; /** winding rule, which parts will become solid */ WindingType _wtype; /** tessellation rule, which parts will become solid */ TessellationType _ttype; bool _boundaryOnly; // see gluTessProperty - if true: make the boundary edges only. /** number of vertices that are part of the 'original' set of contours */ unsigned int _numberVerts; /** List of primitives that define the contours */ osg::Geometry::PrimitiveSetList _Contours; /** count number of primitives in a geometry to get right no. of norms/colurs etc for per_primitive attributes. */ unsigned int _index; /** the gluTessNormal for tessellation hint */ osg::Vec3 tessNormal; /** count of number of extra primitives added */ unsigned int _extraPrimitives; }; } #endif