C++ Geometry::addPrimitiveSet方法代码示例

void
createDAIGeometry( osg::Geometry& geom, int nInstances=1 )
{
    const float halfDimX( .5 );
    const float halfDimZ( .5 );

    osg::Vec3Array* v = new osg::Vec3Array;
    v->resize( 4 );
    geom.setVertexArray( v );

    // Geometry for a single quad.
    (*v)[ 0 ] = osg::Vec3( -halfDimX, 0., -halfDimZ );
    (*v)[ 1 ] = osg::Vec3( halfDimX, 0., -halfDimZ );
    (*v)[ 2 ] = osg::Vec3( halfDimX, 0., halfDimZ );
    (*v)[ 3 ] = osg::Vec3( -halfDimX, 0., halfDimZ );

    // Use the DrawArraysInstanced PrimitiveSet and tell it to draw 1024 instances.
    geom.addPrimitiveSet( new osg::DrawArrays( GL_QUADS, 0, 4, nInstances ) );
}

void createFaces(osg::Geometry& geometry, Polyhedron const& polyhedron, unsigned int faceMask = PolyhedronGeometry::All)
{
    osgUtil::Tessellator tessellator;
    tessellator.setTessellationType(osgUtil::Tessellator::TESS_TYPE_POLYGONS);
    tessellator.setWindingType(osgUtil::Tessellator::TESS_WINDING_NONZERO);

    auto _vertices = getOrCreateVertexArray(geometry);
    auto _normals = getOrCreateNormalArray(geometry);
    auto _colors = getOrCreateColorArray(geometry);

    osg::ref_ptr<osg::Vec3Array> vertices = createVertexArray(polyhedron);
    VertexIndexArrays polygons = createVertexIndexArrays(polyhedron);

    for (auto const& polygon: polygons)
    {
        assert(polygon && polygon->size() >= 3);

        if (!(faceMask & PolyhedronGeometry::FaceMaskFromSides(polygon->size()))) continue;

        auto first = _vertices->size();
        auto count = polygon->size();

        auto normal = detail::calculateNormal(vertices, polygon);
        auto color = detail::calculateColor(vertices, polygon);

        for (auto i = 0u; i < polygon->size(); ++i)
        {
            auto vertex = vertices->at(polygon->at(i));
            _vertices->push_back(vertex);
            _normals->push_back(normal);
            _colors->push_back(color);
        }

        geometry.addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::POLYGON, first, count));
    }

    tessellator.retessellatePolygons(geometry);
}

void createDAIGeometry( osg::Geometry& geom, int nInstances=1 )
{
    const float halfDimX( .5 );
    const float halfDimZ( .5 );

    osg::Vec3Array* v = new osg::Vec3Array;
    v->resize( 4 );
    geom.setVertexArray( v );

    // Geometry for a single quad.
    (*v)[ 0 ] = osg::Vec3( -halfDimX, 0., 0. );
    (*v)[ 1 ] = osg::Vec3( halfDimX, 0., 0. );
    (*v)[ 2 ] = osg::Vec3( halfDimX, 0., halfDimZ*2.0f );
    (*v)[ 3 ] = osg::Vec3( -halfDimX, 0., halfDimZ*2.0f );


	// create color array data (each corner of our triangle will have one color component)
    osg::Vec4Array* pColors = new osg::Vec4Array;
    pColors->push_back( osg::Vec4( 1.0f, 0.0f, 0.0f, 1.0f ) );
    pColors->push_back( osg::Vec4( 0.0f, 1.0f, 0.0f, 1.0f ) );
    pColors->push_back( osg::Vec4( 0.0f, 0.0f, 1.0f, 1.0f ) );
	pColors->push_back( osg::Vec4( 0.0f, 0.0f, 1.0f, 1.0f ) );
    geom.setColorArray( pColors );

	// make sure that our geometry is using one color per vertex
    geom.setColorBinding( osg::Geometry::BIND_PER_VERTEX );

    osg::Vec2Array* pTexCoords = new osg::Vec2Array( 4 );
    (*pTexCoords)[0].set( 0.0f, 0.0f );
    (*pTexCoords)[1].set( 1.0f, 0.0f );
    (*pTexCoords)[2].set( 1.0f, 1.0f );
    (*pTexCoords)[3].set( 0.0f, 1.0f );
    geom.setTexCoordArray( 0, pTexCoords );

    // Use the DrawArraysInstanced PrimitiveSet and tell it to draw 1024 instances.
    geom.addPrimitiveSet( new osg::DrawArrays( GL_QUADS, 0, 4, nInstances ) );
}

bool
Tessellator::tessellateGeometry(osg::Geometry &geom)
{
    osg::Vec3Array* vertices = dynamic_cast<osg::Vec3Array*>(geom.getVertexArray());

    if (!vertices || vertices->empty() || geom.getPrimitiveSetList().empty()) return false;

    // copy the original primitive set list
    osg::Geometry::PrimitiveSetList originalPrimitives = geom.getPrimitiveSetList();

    // clear the primitive sets
    unsigned int nprimsetoriginal= geom.getNumPrimitiveSets();
    if (nprimsetoriginal) geom.removePrimitiveSet(0, nprimsetoriginal);

    bool success = true;
    for (unsigned int i=0; i < originalPrimitives.size(); i++)
    {
        osg::ref_ptr<osg::PrimitiveSet> primitive = originalPrimitives[i].get();

        if (primitive->getMode()==osg::PrimitiveSet::POLYGON || primitive->getMode()==osg::PrimitiveSet::LINE_LOOP)
        {
            if (primitive->getType()==osg::PrimitiveSet::DrawArrayLengthsPrimitiveType)
            {
                osg::DrawArrayLengths* drawArrayLengths = static_cast<osg::DrawArrayLengths*>(primitive.get());
                unsigned int first = drawArrayLengths->getFirst();
                for(osg::DrawArrayLengths::iterator itr=drawArrayLengths->begin();
                    itr!=drawArrayLengths->end();
                    ++itr)
                {
                    unsigned int last = first + *itr;
                    osg::PrimitiveSet* newPrimitive = tessellatePrimitive(first, last, vertices);
                    if (newPrimitive)
                    {
                        geom.addPrimitiveSet(newPrimitive);
                    }
                    else
                    {
                        // tessellation failed, add old primitive set back
                        geom.addPrimitiveSet(primitive);
                        success = false;
                    }

                    first = last;
                }
            }
            else
            {
                if (primitive->getNumIndices()>=3)
                {
                    osg::PrimitiveSet* newPrimitive = tessellatePrimitive(primitive.get(), vertices);
                    if (newPrimitive)
                    {
                        geom.addPrimitiveSet(newPrimitive);
                    }
                    else
                    {
                        // tessellation failed, add old primitive set back
                        geom.addPrimitiveSet(primitive);
                        success = false;
                    }
                }
            }
        }
        else
        {
            //
            // TODO: handle more primitive modes
            //
        }
    }

    return success;
}

bool Primitive_readLocalData(Input& fr,osg::Geometry& geom)
{
    bool iteratorAdvanced = false;
    bool firstMatched = false;
    if ((firstMatched = fr.matchSequence("DrawArrays %w %i %i %i")) ||
         fr.matchSequence("DrawArrays %w %i %i") )
    {

        GLenum mode;
        Geometry_matchPrimitiveModeStr(fr[1].getStr(),mode);

        int first;
        fr[2].getInt(first);

        int count;
        fr[3].getInt(count);

        int numInstances = 0;
        if (firstMatched)
        {
            fr[4].getInt(numInstances);
            fr += 5;
        }
        else
        {
            fr += 4;
        }

        geom.addPrimitiveSet(new DrawArrays(mode, first, count, numInstances));


        iteratorAdvanced = true;

    }
    else if ((firstMatched = fr.matchSequence("DrawArrayLengths %w %i %i %i {")) ||
         fr.matchSequence("DrawArrayLengths %w %i %i {") )
    {
        int entry = fr[1].getNoNestedBrackets();

        GLenum mode;
        Geometry_matchPrimitiveModeStr(fr[1].getStr(),mode);

        int first;
        fr[2].getInt(first);

        int capacity;
        fr[3].getInt(capacity);

        int numInstances = 0;
        if (firstMatched)
        {
            fr[4].getInt(numInstances);
            fr += 6;
        }
        else
        {
            fr += 5;
        }

        DrawArrayLengths* prim = new DrawArrayLengths;
        prim->setMode(mode);
        prim->setNumInstances(numInstances);
        prim->setFirst(first);
        prim->reserve(capacity);

        while (!fr.eof() && fr[0].getNoNestedBrackets()>entry)
        {
            unsigned int i;
            if (fr[0].getUInt(i))
            {
                prim->push_back(i);
                ++fr;
            }
        }
         ++fr;

         geom.addPrimitiveSet(prim);

        iteratorAdvanced = true;
    }
    else if ((firstMatched = fr.matchSequence("DrawElementsUByte %w %i %i {")) ||
         fr.matchSequence("DrawElementsUByte %w %i {"))
    {
        int entry = fr[1].getNoNestedBrackets();

        GLenum mode;
        Geometry_matchPrimitiveModeStr(fr[1].getStr(),mode);

        int capacity;
        fr[2].getInt(capacity);

        int numInstances = 0;
        if (firstMatched)
        {
            fr[3].getInt(numInstances);
            fr += 5;
        }
        else
        {
            fr += 4;
//.........这里部分代码省略.........

void Tessellator::collectTessellation(osg::Geometry &geom, unsigned int originalIndex)
{
    osg::Vec3Array* vertices = dynamic_cast<osg::Vec3Array*>(geom.getVertexArray());
    VertexPtrToIndexMap vertexPtrToIndexMap;
    
    // populate the VertexPtrToIndexMap.
    for(unsigned int vi=0;vi<vertices->size();++vi)
    {
        vertexPtrToIndexMap[&((*vertices)[vi])] = vi;
    }
    
    handleNewVertices(geom, vertexPtrToIndexMap);
    
    // we don't properly handle per primitive and per primitive_set bindings yet
    // will need to address this soon. Robert Oct 2002.
    {
        osg::Vec3Array* normals = NULL; // GWM Sep 2002 - add normals for extra facets
        int iprim=0;
        if (geom.getNormalBinding()==osg::Geometry::BIND_PER_PRIMITIVE ||
            geom.getNormalBinding()==osg::Geometry::BIND_PER_PRIMITIVE_SET)
        {
            normals = dynamic_cast<osg::Vec3Array*>(geom.getNormalArray()); // GWM Sep 2002
        }
        // GWM Dec 2003 - needed to add colours for extra facets
        osg::Vec4Array* cols4 = NULL; // GWM Dec 2003 colours are vec4
        osg::Vec3Array* cols3 = NULL; // GWM Dec 2003 colours are vec3
        if (geom.getColorBinding()==osg::Geometry::BIND_PER_PRIMITIVE ||
              geom.getColorBinding()==osg::Geometry::BIND_PER_PRIMITIVE_SET)
        {
              Array* colours = geom.getColorArray(); // GWM Dec 2003 - need to duplicate face colours
              switch (colours->getType()) {
              case osg::Array::Vec4ArrayType:
                  cols4=dynamic_cast<osg::Vec4Array *> (colours);
                  break;
              case osg::Array::Vec3ArrayType:
                  cols3=dynamic_cast<osg::Vec3Array *> (colours);
                  break;
              default:
                  break;
              }
              
        }
        // GWM Dec 2003 - these holders need to go outside the loop to 
        // retain the flat shaded colour &/or normal for each tessellated polygon
        osg::Vec3 norm(0.0f,0.0f,0.0f);
        osg::Vec4 primCol4(0.0f,0.0f,0.0f,1.0f);
        osg::Vec3 primCol3(0.0f,0.0f,0.0f);

        for(PrimList::iterator primItr=_primList.begin();
        primItr!=_primList.end();
        ++primItr, ++_index)
        {
              Prim* prim=primItr->get();
              int ntris=0;

              if(vertexPtrToIndexMap.size() <= 255)
              {
                  osg::DrawElementsUByte* elements = new osg::DrawElementsUByte(prim->_mode);
                  for(Prim::VecList::iterator vitr=prim->_vertices.begin();
                  vitr!=prim->_vertices.end();
                  ++vitr)
                {
                    elements->push_back(vertexPtrToIndexMap[*vitr]);
                }

                  // add to the drawn primitive list.
                  geom.addPrimitiveSet(elements);
                  ntris=elements->getNumIndices()/3;
              }
              else if(vertexPtrToIndexMap.size() > 255 && vertexPtrToIndexMap.size() <= 65535)
              {
                  osg::DrawElementsUShort* elements = new osg::DrawElementsUShort(prim->_mode);
                  for(Prim::VecList::iterator vitr=prim->_vertices.begin();
                    vitr!=prim->_vertices.end();
                    ++vitr)
                  {
                    elements->push_back(vertexPtrToIndexMap[*vitr]);
                  }

                  // add to the drawn primitive list.
                  geom.addPrimitiveSet(elements);
                  ntris=elements->getNumIndices()/3;
              }
              else
              {
                  osg::DrawElementsUInt* elements = new osg::DrawElementsUInt(prim->_mode);
                  for(Prim::VecList::iterator vitr=prim->_vertices.begin();
                    vitr!=prim->_vertices.end();
                    ++vitr)
                  {
                    elements->push_back(vertexPtrToIndexMap[*vitr]);
                  }

                  // add to the drawn primitive list.
                  geom.addPrimitiveSet(elements);
                  ntris=elements->getNumIndices()/3;
              }

              if (primItr==_primList.begin()) 
              {   // first primitive so collect primitive normal & colour.
//.........这里部分代码省略.........

void Tessellator::retessellatePolygons(osg::Geometry &geom)
{
#ifdef OSG_GLU_AVAILABLE
    // turn the contour list into primitives, a little like Tessellator does but more generally
    osg::Vec3Array* vertices = dynamic_cast<osg::Vec3Array*>(geom.getVertexArray());
    
    if (!vertices || vertices->empty() || geom.getPrimitiveSetList().empty()) return;


    // we currently don't handle geometry which use indices...
    if (geom.getVertexIndices() ||
        geom.getNormalIndices() ||
        geom.getColorIndices() ||
        geom.getSecondaryColorIndices() ||
        geom.getFogCoordIndices()) return;
        
    // not even text coord indices don't handle geometry which use indices...
    for(unsigned int unit=0;unit<geom.getNumTexCoordArrays();++unit)
    {
        if (geom.getTexCoordIndices(unit)) return;
    }

    if (_ttype==TESS_TYPE_POLYGONS || _ttype==TESS_TYPE_DRAWABLE) _numberVerts=0; // 09.04.04 GWM reset Tessellator
    // the reset is needed by the flt loader which reuses a Tessellator for triangulating polygons.
    // as such it might be reset by other loaders/developers in future.
    _index=0; // reset the counter for indexed vertices
    _extraPrimitives = 0;
    if (!_numberVerts) {
        _numberVerts=geom.getVertexArray()->getNumElements();
        // save the contours for complex (winding rule) tessellations
        _Contours=geom.getPrimitiveSetList();
    }

    // now cut out vertex attributes added on any previous tessellation
    reduceArray(geom.getVertexArray(), _numberVerts);
    reduceArray(geom.getColorArray(), _numberVerts);
    reduceArray(geom.getNormalArray(), _numberVerts);
    reduceArray(geom.getFogCoordArray(), _numberVerts);
    for(unsigned int unit1=0;unit1<geom.getNumTexCoordArrays();++unit1)
    {
        reduceArray(geom.getTexCoordArray(unit1), _numberVerts);
    }

    // remove the existing primitives.
    unsigned int nprimsetoriginal= geom.getNumPrimitiveSets();
    if (nprimsetoriginal) geom.removePrimitiveSet(0, nprimsetoriginal);

    // the main difference from osgUtil::Tessellator for Geometry sets of multiple contours is that the begin/end tessellation
    // occurs around the whole set of contours.
    if (_ttype==TESS_TYPE_GEOMETRY) {
        beginTessellation();
        gluTessProperty(_tobj, GLU_TESS_WINDING_RULE, _wtype);
        gluTessProperty(_tobj, GLU_TESS_BOUNDARY_ONLY , _boundaryOnly);
    }
    // process all the contours into the Tessellator
    int noContours = _Contours.size();
    int currentPrimitive = 0;
    for(int primNo=0;primNo<noContours;++primNo)
    {
        osg::ref_ptr<osg::PrimitiveSet> primitive = _Contours[primNo].get();
        if (_ttype==TESS_TYPE_POLYGONS || _ttype==TESS_TYPE_DRAWABLE)
        { // this recovers the 'old' tessellation which just retessellates single polygons.
            if (primitive->getMode()==osg::PrimitiveSet::POLYGON || _ttype==TESS_TYPE_DRAWABLE)
            {

                if (primitive->getType()==osg::PrimitiveSet::DrawArrayLengthsPrimitiveType)
                {
                    osg::DrawArrayLengths* drawArrayLengths = static_cast<osg::DrawArrayLengths*>(primitive.get());
                    unsigned int first = drawArrayLengths->getFirst(); 
                    for(osg::DrawArrayLengths::iterator itr=drawArrayLengths->begin();
                        itr!=drawArrayLengths->end();
                        ++itr)
                    {
                        beginTessellation();
                            unsigned int last = first + *itr;
                            addContour(primitive->getMode(),first,last,vertices);
                            first = last;
                        endTessellation();
                        collectTessellation(geom, currentPrimitive);
                        currentPrimitive++;
                    }
                }
                else
                {
                    if (primitive->getNumIndices()>3) { // April 2005 gwm only retessellate "complex" polygons
                        beginTessellation();
                        addContour(primitive.get(), vertices);
                        endTessellation();
                        collectTessellation(geom, currentPrimitive);
                        currentPrimitive++;
                    } else { // April 2005 gwm triangles don't need to be retessellated
                        geom.addPrimitiveSet(primitive.get());
                    }
                }

            }
            else
            { // copy the contour primitive as it is not being tessellated
                geom.addPrimitiveSet(primitive.get());
            }
//.........这里部分代码省略.........

	nave(int x,int y, int z, int tamaño)
		{
		pyramidGeode = new osg::Geode();
		pyramidGeometry = new osg::Geometry();
		pyramidGeode->addDrawable(pyramidGeometry);
		
		osg::Vec3Array* pyramidVertices = new osg::Vec3Array;
	
	//0-4
	pyramidVertices->push_back( osg::Vec3(       x,       y,       z) ); // front left
    //1-5
	pyramidVertices->push_back( osg::Vec3(tamaño+x,       y,       z) ); // front right
    //2-6
	pyramidVertices->push_back( osg::Vec3(tamaño+x,tamaño+y,       z) ); // back right
    //3-7
	pyramidVertices->push_back( osg::Vec3(       x,tamaño+y,       z) ); // back left
	//4-0
    pyramidVertices->push_back( osg::Vec3(	     x,		  y,tamaño+z) ); // peak
    //5-1
	pyramidVertices->push_back( osg::Vec3(tamaño+x,       y,tamaño+z) ); // front right
    //6-2
	pyramidVertices->push_back( osg::Vec3(tamaño+x,tamaño+y,tamaño+z) ); // back right
    //7-3
	pyramidVertices->push_back( osg::Vec3(       x,tamaño+y,tamaño+z) ); // back left	
		
	pyramidGeometry->setVertexArray( pyramidVertices );
		
		osg::DrawElementsUInt* pyramidBase =
        new osg::DrawElementsUInt(osg::PrimitiveSet::QUADS, 0);
    pyramidBase->push_back(3);
    pyramidBase->push_back(2);
    pyramidBase->push_back(1);
    pyramidBase->push_back(0);
    pyramidGeometry->addPrimitiveSet(pyramidBase);

	osg::DrawElementsUInt* pyramidTop =
        new osg::DrawElementsUInt(osg::PrimitiveSet::QUADS, 0);
    pyramidTop->push_back(4);
    pyramidTop->push_back(5);
    pyramidTop->push_back(6);
    pyramidTop->push_back(7);
    pyramidGeometry->addPrimitiveSet(pyramidTop);

    //Repeat the same for each of the four sides. Again, vertices are
    //specified in counter-clockwise order.

    osg::DrawElementsUInt* pyramidFaceOne =
        new osg::DrawElementsUInt(osg::PrimitiveSet::QUADS, 0);
    pyramidFaceOne->push_back(0);
    pyramidFaceOne->push_back(1);
	pyramidFaceOne->push_back(5);
    pyramidFaceOne->push_back(4);
	pyramidGeometry->addPrimitiveSet(pyramidFaceOne);

    osg::DrawElementsUInt* pyramidFaceTwo =
        new osg::DrawElementsUInt(osg::PrimitiveSet::QUADS, 0);
    pyramidFaceTwo->push_back(1);
    pyramidFaceTwo->push_back(2);
    pyramidFaceTwo->push_back(6);
	pyramidFaceTwo->push_back(5);
    pyramidGeometry->addPrimitiveSet(pyramidFaceTwo);

    osg::DrawElementsUInt* pyramidFaceThree =
        new osg::DrawElementsUInt(osg::PrimitiveSet::QUADS, 0);
    pyramidFaceThree->push_back(2);
    pyramidFaceThree->push_back(3);
    pyramidFaceThree->push_back(7);
	pyramidFaceThree->push_back(6);
    pyramidGeometry->addPrimitiveSet(pyramidFaceThree);

    osg::DrawElementsUInt* pyramidFaceFour =
        new osg::DrawElementsUInt(osg::PrimitiveSet::QUADS, 0);
    pyramidFaceFour->push_back(3);
    pyramidFaceFour->push_back(0);
    pyramidFaceThree->push_back(4);
	pyramidFaceFour->push_back(7);
    pyramidGeometry->addPrimitiveSet(pyramidFaceFour);

    //Declare and load an array of Vec4 elements to store colors.

    osg::Vec4Array* colors = new osg::Vec4Array;
    colors->push_back(osg::Vec4(0.0f, 0.0f, 0.0f, 1.0f) ); //index 0 red
    colors->push_back(osg::Vec4(0.0f, 0.0f, 0.0f, 1.0f) ); //index 1 green
    colors->push_back(osg::Vec4(0.0f, 0.0f, 0.0f, 1.0f) ); //index 2 blue
    colors->push_back(osg::Vec4(0.0f, 0.0f, 0.0f, 1.0f) ); //index 3 white
    colors->push_back(osg::Vec4(1.0f, 1.0f, 1.0f, 1.0f) ); //index 4 red
	 colors->push_back(osg::Vec4(1.0f, 1.0f, 1.0f, 1.0f) ); //index 4 red
	  colors->push_back(osg::Vec4(1.0f, 1.0f, 1.0f, 1.0f) ); //index 4 red
	   colors->push_back(osg::Vec4(1.0f, 1.0f, 1.0f, 1.0f) ); //index 4 red

    //The next step is to associate the array of colors with the geometry,
    //assign the color indices created above to the geometry and set the
    //binding mode to _PER_VERTEX.

    pyramidGeometry->setColorArray(colors);
    pyramidGeometry->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
	
		};