#include "terrain.h"

void Terrain::split()
{
	if(is_split())
		return;

	quads[0][0] = new Terrain(V);
	quads[0][1] = new Terrain(V);
	quads[1][0] = new Terrain(V);
	quads[1][1] = new Terrain(V);

	quads[0][0]->set_range(*x1(), *x_mid(), *y1(), *y_mid());
	quads[0][1]->set_range(*x_mid(), *x2(), *y1(), *y_mid());
	quads[1][0]->set_range(*x1(), *x_mid(), *y_mid(), *y2());
	quads[1][1]->set_range(*x_mid(), *x2(), *y_mid(), *y2());
}

void Terrain::track_down(double x, double y, double nz, int levels)
{
	if( levels > 0 ) {
		int a = ( x < *x_mid() ) ? 0 : 1;
		int b = ( y < *y_mid() ) ? 0 : 1;

		if( !is_split() )
			split();

		dynamic_cast<Terrain*>(quads[b][a])->track_down(x, y, nz, levels-1);
	}
	else {
		z[0][0]=
		z[0][1]=
		z[1][1]=
		z[1][0] = z_mean_ = nz;
	}
}