06e88f3b91
The initialisation of glu low level tessellator is done in osgUtil::Tessellator::beginTessellation() This function is not virtual, preventing any customization of the tesselation. In particular, there in an option in glu tesselator that force the generated primitives to be triangles and that I'd like to use (GLU_TESS_EDGE_FLAG). "
252 lines
8.8 KiB
C++
252 lines
8.8 KiB
C++
/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
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*
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* This library is open source and may be redistributed and/or modified under
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* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
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* (at your option) any later version. The full license is in LICENSE file
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* included with this distribution, and on the openscenegraph.org website.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* OpenSceneGraph Public License for more details.
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*/
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#ifndef OSGUTIL_Tessellator
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#define OSGUTIL_Tessellator
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#include <osg/Geometry>
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#include <osgUtil/Export>
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#include <osg/GLU>
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#include <vector>
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#ifndef CALLBACK
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/* Win32 calling conventions. (or a least thats what the GLUT example tess.c uses.)*/
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#define CALLBACK
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#endif
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namespace osgUtil {
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/** Originally a simple class for tessellating a single polygon boundary.
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* Using old style glu tessellation functions for portability.
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* Upgraded Jan 2004 to use the modern glu tessellation functions.*/
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class OSGUTIL_EXPORT Tessellator : public osg::Referenced
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{
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public:
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Tessellator();
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~Tessellator();
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/** The winding rule, see red book ch 11. */
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enum WindingType{
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TESS_WINDING_ODD = GLU_TESS_WINDING_ODD,
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TESS_WINDING_NONZERO = GLU_TESS_WINDING_NONZERO,
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TESS_WINDING_POSITIVE = GLU_TESS_WINDING_POSITIVE,
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TESS_WINDING_NEGATIVE = GLU_TESS_WINDING_NEGATIVE,
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TESS_WINDING_ABS_GEQ_TWO = GLU_TESS_WINDING_ABS_GEQ_TWO
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} ;
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/** we interpret all contours in the geometry as a single set to be tessellated or
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* each separate drawable's contours needs to be tessellated. */
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enum TessellationType {
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TESS_TYPE_GEOMETRY, // tessellate everything in the geometry object
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TESS_TYPE_DRAWABLE, // tessellate each polygon, triangles & quads drawables in geometry separately
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TESS_TYPE_POLYGONS // tessellate ONLY polygon drawables in geometry separately
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};
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/** Set and get tessellation request boundary only on/off */
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void setBoundaryOnly (const bool tt) { _boundaryOnly=tt;}
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inline bool getBoundaryOnly ( ) { return _boundaryOnly;}
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/** Set and get tessellation windong rule */
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void setWindingType (const WindingType wt) { _wtype=wt;}
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inline WindingType getWindingType ( ) { return _wtype;}
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/** Set and get tessellation type */
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void setTessellationType (const TessellationType tt) { _ttype=tt;}
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inline TessellationType getTessellationType ( ) { return _ttype;}
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/** Change the contours lists of the geometry into tessellated primitives (the
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* list of primitives in the original geometry is stored in the Tessellator for
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* possible re-use.
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* The name remains retessellatePolygons although it now handles trifans, strips, quads etc.
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* as well as Polygons so as to not break old codes relying on this function name. */
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void retessellatePolygons(osg::Geometry &cxgeom);
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/** Define the normal to the tessellated polygon - this provides a hint how to
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* tessellate the contours; see gluTessNormal in red book or man pages.
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* GWM July 2005. Can improve teselation
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* "For example, if you know that all polygons lie in the x-y plane,
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* call gluTessNormal(tess, 0.0, 0.0, 1.0) before rendering any polygons."
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*/
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void setTessellationNormal(const osg::Vec3 norm) { tessNormal=norm;}
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osg::Geometry::PrimitiveSetList getContours() { return _Contours;}
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struct Prim : public osg::Referenced
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{
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Prim(GLenum mode):_mode(mode) {}
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typedef std::vector<osg::Vec3*> VecList;
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GLenum _mode;
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VecList _vertices;
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};
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virtual void beginTessellation();
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void beginContour();
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/** Add a vertex to the current contour, see gluTessVertex for details.
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* Note the vertex pointer is returned at the end of tessellation and
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* must not be left dangling or be overwritten until all results are
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* collected.
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*/
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void addVertex(osg::Vec3* vertex);
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void endContour();
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void endTessellation();
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typedef std::vector< osg::ref_ptr<Prim> > PrimList;
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PrimList& getPrimList() { return _primList; }
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void reset();
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protected:
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/** remove unused parts of the array, eg for when retessellating
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* tessellation can introduce extra vertices for concave or crossing boundaries,
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* these will leak memory if not removed when retessellating. */
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void reduceArray(osg::Array * cold, const unsigned int nnu);
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void collectTessellation(osg::Geometry &cxgeom, unsigned int originalIndex);
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typedef std::map<osg::Vec3*,unsigned int> VertexPtrToIndexMap;
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void addContour(GLenum mode, unsigned int first, unsigned int last, osg::Vec3Array* vertices);
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void addContour(osg::PrimitiveSet* primitive, osg::Vec3Array* vertices);
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void handleNewVertices(osg::Geometry& geom,VertexPtrToIndexMap &vertexPtrToIndexMap);
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void begin(GLenum mode);
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void vertex(osg::Vec3* vertex);
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void combine(osg::Vec3* vertex,void* vertex_data[4],GLfloat weight[4]);
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void end();
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void error(GLenum errorCode);
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static void CALLBACK beginCallback(GLenum which, void* userData);
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static void CALLBACK vertexCallback(GLvoid *data, void* userData);
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static void CALLBACK combineCallback(GLdouble coords[3], void* vertex_data[4],
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GLfloat weight[4], void** outData,
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void* useData);
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static void CALLBACK endCallback(void* userData);
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static void CALLBACK errorCallback(GLenum errorCode, void* userData);
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struct Vec3d
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{
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double _v[3];
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};
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struct NewVertex
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{
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NewVertex():
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_vpos(0),
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_f1(0),
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_v1(0),
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_f2(0),
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_v2(0),
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_f3(0),
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_v3(0),
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_f4(0),
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_v4(0) {}
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NewVertex(const NewVertex& nv):
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_vpos(nv._vpos),
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_f1(nv._f1),
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_v1(nv._v1),
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_f2(nv._f2),
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_v2(nv._v2),
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_f3(nv._f3),
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_v3(nv._v3),
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_f4(nv._f4),
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_v4(nv._v4) {}
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NewVertex(osg::Vec3* vx,
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float f1,osg::Vec3* v1,
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float f2,osg::Vec3* v2,
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float f3,osg::Vec3* v3,
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float f4,osg::Vec3* v4):
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_vpos(vx),
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_f1(f1),
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_v1(v1),
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_f2(f2),
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_v2(v2),
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_f3(f3),
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_v3(v3),
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_f4(f4),
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_v4(v4) {}
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osg::Vec3 *_vpos; // added gwm Jan 2004 the vertex coords s.t. NewVertex can be used in a std::vector
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float _f1;
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osg::Vec3* _v1;
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float _f2;
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osg::Vec3* _v2;
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float _f3;
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osg::Vec3* _v3;
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float _f4;
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osg::Vec3* _v4;
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};
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//change NewVertexList from std::map<osg::Vec3*,NewVertex> NewVertexList;
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// because this has undefined order of insertion for new vertices.
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// which occasionally corrupted the texture mapping.
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typedef std::vector<NewVertex> NewVertexList;
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typedef std::vector<Vec3d*> Vec3dList;
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osg::GLUtesselator* _tobj;
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PrimList _primList;
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Vec3dList _coordData;
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NewVertexList _newVertexList;
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GLenum _errorCode;
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/** winding rule, which parts will become solid */
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WindingType _wtype;
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/** tessellation rule, which parts will become solid */
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TessellationType _ttype;
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bool _boundaryOnly; // see gluTessProperty - if true: make the boundary edges only.
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/** number of vertices that are part of the 'original' set of contours */
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unsigned int _numberVerts;
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/** List of primitives that define the contours */
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osg::Geometry::PrimitiveSetList _Contours;
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/** count number of primitives in a geometry to get right no. of norms/colurs etc for per_primitive attributes. */
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unsigned int _index;
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/** the gluTessNormal for tessellation hint */
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osg::Vec3 tessNormal;
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/** count of number of extra primitives added */
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unsigned int _extraPrimitives;
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};
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}
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#endif
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