OpenSceneGraph/include/osgUtil/Tessellator
2012-03-21 17:36:20 +00:00

252 lines
8.7 KiB
C++

/* -*-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 <osg/Geometry>
#include <osgUtil/Export>
#include <osg/GLU>
#include <vector>
#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<osg::Vec3*> 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<Prim> > 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<osg::Vec3*,unsigned int> 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<osg::Vec3*,NewVertex> NewVertexList;
// because this has undefined order of insertion for new vertices.
// which occasionally corrupted the texture mapping.
typedef std::vector<NewVertex> NewVertexList;
typedef std::vector<Vec3d*> 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