Building.hpp

#ifndef BLDG_HPP
#define BLDG_HPP

#include <gdal/ogrsf_frmts.h>

class Building
{
public:
    Building():_footprint(0) {}
    Building(OGRPolygon* ply,double h,int idLot=-1):_footprint((OGRPolygon*)(ply->clone())),_h(h),_idLot(idLot) {}
    Building(const Building& o){
        _footprint = (OGRPolygon*)(o._footprint->clone());
        _h = o._h;
        _idLot = o._idLot;
    }
    ~Building(){if(_footprint) _footprint->empty();}

    inline OGRPolygon* footprint() const{return _footprint;}
    inline double height() const{return _h;}
    inline int idLot() const{return _idLot;}

    inline OGRMultiPolygon* extrude() const
    {
        OGRMultiPolygon* block = new OGRMultiPolygon;

        //extrude roof
        OGRPolygon roof;
        {
            roof.addRing(_footprint->getExteriorRing());
            OGRLinearRing* ring = roof.getExteriorRing();
            for(int i=0; i<ring->getNumPoints(); i++)
                ring->setPoint(i,ring->getX(i),ring->getY(i),_h);
        }

        if(int n = _footprint->getNumInteriorRings())
        {
            for (int j=0; j<n; j++)
            {
                roof.addRing(_footprint->getInteriorRing(j));
                OGRLinearRing* ring = roof.getInteriorRing(j);
                for(int i=0; i<ring->getNumPoints(); i++)
                    ring->setPoint(i,ring->getX(i),ring->getY(i),_h);
            }
        }

        block->addGeometry(&roof);

        //extrude exter walls
        OGRLinearRing* ringEx = _footprint->getExteriorRing();
        for(int i=0; i<ringEx->getNumPoints()-1; i++)
        {
            OGRPolygon wall;
            OGRLinearRing ring;
            ring.addPoint(ringEx->getX(i),ringEx->getY(i),0);
            ring.addPoint(ringEx->getX(i+1),ringEx->getY(i+1),0);
            ring.addPoint(ringEx->getX(i+1),ringEx->getY(i+1),_h);
            ring.addPoint(ringEx->getX(i),ringEx->getY(i),_h);
            ring.addPoint(ringEx->getX(i),ringEx->getY(i),0);
            wall.addRing(&ring);
            block->addGeometry(&wall);
        }

        //extrude inner walls if exist
        if(int n = _footprint->getNumInteriorRings())
        {
            for (int i=0; i<n; i++)
            {
                OGRLinearRing* ringIn = _footprint->getInteriorRing(i);
                for(int j=0; j<ringIn->getNumPoints()-1; j++)
                {
                    OGRPolygon wall;
                    OGRLinearRing ring;
                    ring.addPoint(ringIn->getX(j),ringIn->getY(j),0);
                    ring.addPoint(ringIn->getX(j+1),ringIn->getY(j+1),0);
                    ring.addPoint(ringIn->getX(j+1),ringIn->getY(j+1),_h);
                    ring.addPoint(ringIn->getX(j),ringIn->getY(j),_h);
                    ring.addPoint(ringIn->getX(j),ringIn->getY(j),0);
                    wall.addRing(&ring);
                    block->addGeometry(&wall);
                }
            }
        }

        return block;

    }

private:
    OGRPolygon* _footprint;
    double _h;
    int _idLot;

};

#endif