C++ FilterContext::referenceFrame方法代码示例

//.........这里部分代码省略.........
        
        osg::Geometry* osgGeom = new osg::Geometry();

        if ( _featureNameExpr.isSet() )
        {
            const std::string& name = input->eval( _featureNameExpr.mutable_value() );
            osgGeom->setName( name );
        }

        osgGeom->setUseVertexBufferObjects( true );
        osgGeom->setUseDisplayList( false );

        if ( setWidth && width != 1.0f )
        {
            osgGeom->getOrCreateStateSet()->setAttributeAndModes(
                new osg::LineWidth( width ), osg::StateAttribute::ON );
        }
        
        if (part->getType() == Geometry::TYPE_POLYGON && static_cast<Polygon*>(part)->getHoles().size() > 0 )
        {
            Polygon* poly = static_cast<Polygon*>(part);
            int totalPoints = poly->getTotalPointCount();
            osg::Vec3Array* allPoints = new osg::Vec3Array( totalPoints );

            std::copy( part->begin(), part->end(), allPoints->begin() );
            osgGeom->addPrimitiveSet( new osg::DrawArrays( primMode, 0, part->size() ) );

            int offset = part->size();

            for( RingCollection::const_iterator h = poly->getHoles().begin(); h != poly->getHoles().end(); ++h )
            {
                Geometry* hole = h->get();
                if ( hole->isValid() )
                {
                    std::copy( hole->begin(), hole->end(), allPoints->begin() + offset );
                    osgGeom->addPrimitiveSet( new osg::DrawArrays( primMode, offset, hole->size() ) );
                    offset += hole->size();
                }
            }
            osgGeom->setVertexArray( allPoints );
        }
        else
        {
            osgGeom->setVertexArray( part->toVec3Array() );
            osgGeom->addPrimitiveSet( new osg::DrawArrays( primMode, 0, part->size() ) );
        }

        // tessellate all polygon geometries. Tessellating each geometry separately
        // with TESS_TYPE_GEOMETRY is much faster than doing the whole bunch together
        // using TESS_TYPE_DRAWABLE.

        if ( part->getType() == Geometry::TYPE_POLYGON && tessellatePolys )
        {
            osgUtil::Tessellator tess;
            //tess.setTessellationType( osgUtil::Tessellator::TESS_TYPE_DRAWABLE );
            //tess.setWindingType( osgUtil::Tessellator::TESS_WINDING_ODD );
            tess.setTessellationType( osgUtil::Tessellator::TESS_TYPE_GEOMETRY );
            tess.setWindingType( osgUtil::Tessellator::TESS_WINDING_POSITIVE );

            tess.retessellatePolygons( *osgGeom );

            // the tessellator results in a collection of trifans, strips, etc. This step will
            // consolidate those into one (or more if necessary) GL_TRIANGLES primitive.
            MeshConsolidator::run( *osgGeom );

            // mark this geometry as DYNAMIC because otherwise the OSG optimizer will destroy it.
            //osgGeom->setDataVariance( osg::Object::DYNAMIC );
        }

        if ( context.isGeocentric() && part->getType() != Geometry::TYPE_POINTSET )
        {
            double threshold = osg::DegreesToRadians( *_maxAngle_deg );

            MeshSubdivider ms( context.referenceFrame(), context.inverseReferenceFrame() );
            //ms.setMaxElementsPerEBO( INT_MAX );
            ms.run( threshold, *osgGeom );
        }

        // set the color array. We have to do this last, otherwise it screws up any modifications
        // make by the MeshSubdivider. No idea why. gw

        //osg::Vec4Array* colors = new osg::Vec4Array( osgGeom->getVertexArray()->getNumElements() );
        //for( unsigned c = 0; c < colors->size(); ++c )
        //    (*colors)[c] = color;
        //osgGeom->setColorArray( colors );
        //osgGeom->setColorBinding( osg::Geometry::BIND_PER_VERTEX );

        // NOTE! per-vertex colors makes the optimizer destroy the geometry....

        osg::Vec4Array* colors = new osg::Vec4Array(1);
        (*colors)[0] = color;
        osgGeom->setColorArray( colors );
        osgGeom->setColorBinding( osg::Geometry::BIND_OVERALL );

        // add the part to the geode.
        _geode->addDrawable( osgGeom );
    }
    
    return true;
}