ray cast function

gistfile1.cpp

void RayTracer::draw(const Scene &s, Screen& screen){

	int w = screen.getWidth();
	cout << "Width is: " << w << endl;
	int h = screen.getHeight();

	double tanfov = tan(s.getEye().fov/2.0);
	double d = boost::numeric::ublas::norm_2(s.getEye().eyepoint - s.getEye().lookat);
	//cout << d << endl;
	//cout << tanfov << endl;
	//cout << "screen width : " << d * tanfov << endl;
	double s_width = d *tanfov;
	double s_height = (s_width * h) / w;
	double p_width = (s_width * 2) / w;
	double p_height = (s_height * 2) /h;

	//cout << s_width << endl;
	//cout << s_height << endl;
	//cout << p_width << endl;
	//cout << p_height << endl;
	boost::numeric::ublas::vector<double> u = s.getEye().lookup - s.getEye().lookat; //vertical unit (up positive)
	u /= boost::numeric::ublas::norm_2(u);
	//cout << "U: " << u << endl;
	boost::numeric::ublas::vector<double> v = cross((s.getEye().lookat - s.getEye().eyepoint), u) ; //horizontal unit (right positive)
	v /= boost::numeric::ublas::norm_2(v);
	//cout << "V: " << v << endl;

	for(int i = 0;i<h; ++i){
		cout << "pix " << i << endl;
		for(int j = 0;j<w;++j){
			//for each pixel
			
			//cout << -s_width << " and " << j*p_width << " * " << v << endl;
			boost::numeric::ublas::vector<double> aim = ((-s_width + (j*p_width)) * v) + ((s_height - (i*p_width)) * u);
			boost::numeric::ublas::vector<double> direction = aim - s.getEye().eyepoint;
			direction /= boost::numeric::ublas::norm_2(direction);
			//cout << "Direction: " << direction << endl;
			//exit(1);
			Ray r(s.getEye().eyepoint, direction);
			//cout << s.getColour(r).r;
			screen.setPixel(i,j,s.getColour(r));
		}
		//cout << endl;
	}




	
}