import java.awt.*;

class HalfSpace 
{
    public double a, b, c;
    public Segment s;

    public HalfSpace(Segment s, double a, double b, double c)
    {
	this.s = s;
	this.a = a;
	this.b = b;
	this.c = c;
    }

    public void draw(Graphics g, Color clr)
    {
	return; // FIXME: figure out how to draw this later
    }

    public boolean inPosPlane(Node n)
    {
	boolean result = a*n.x + b*n.y + c > 0;
	//	System.out.println("inPosPlane: "+n+" "+result);
	return result;
    }

    public Node intersect(HalfSpace hs)
    {
	double det = a*hs.b - b*hs.a;
	Util.assert(Math.abs(det) > 0.0001, 
		    "HalfSpace::intersect() "+this+" "+hs);
	double x = (b*hs.c - hs.b*c)/det;
	double y = (c*hs.a - a*hs.c)/det;
	return new Node((int)Math.round(x), (int)Math.round(y));
    }

    public String toString()
    {
	return "HS["+a+","+b+","+c+"]";
    }
}