cogelevation.cxx

Delaunay三角形的网格剖分程序

#include "cogelevation.hxx"

CogeometryElevationMap::CogeometryElevationMap(cogIndex lx, cogIndex ly
	     ,cogeometry geom)
:CogeometryByFunction(*(cogPointToFloat*)this,geom)
,map(lx,ly),x0(0),y0(0),f0(0),dx(1),dy(1),df(0x7fff)
{dx /= map.lx(); dy /= map.ly();}

CogeometryElevationMap::CogeometryElevationMap(wzString s
	     ,cogeometry geom)
:CogeometryByFunction(*(cogPointToFloat*)this,geom)
,map(s),x0(0),y0(0),f0(0),dx(1),dy(1),df(0x7fff)
{dx /= map.lx(); dy /= map.ly();}

wzFloat CogeometryElevationMap::call(const wzPoint& p) const
{
 cogFloat rx = (p.x()-x0)/dx; 
 cogFloat ry = (p.y()-y0)/dy; 
 cogInteger ix = (cogInteger) rx, jx = ix+1; rx -= ix;
 cogInteger iy = (cogInteger) ry, jy = iy+1; ry -= iy;
 if(ix<0){
        ix = jx = 0;
 }else if(jx>=map.lx()){
        ix = jx = map.lx()-1;
 }
 if(iy<0){
        iy = jy = 0;
 }else if(jy>=map.ly()){
        iy = jy = map.ly()-1;
 }
 cogFloat uii = map(ix,iy);
 cogFloat uij = map(ix,jy);
 cogFloat uji = map(jx,iy);
 cogFloat ujj = map(jx,jy);
 cogFloat u   = (1-rx)*((1-ry)*uii + ry * uij) + rx*((1-ry)*uji + ry * ujj);
 return p.z()-(u-f0)/df;
}