package com.aaaaahhhhhhh.bananapuncher714.mesh;

import java.util.List;

/**
 * A list of points denoting the shape of the polygon. May contain self intersections,
 * duplicate vertices, and overlapping edges.
 * 
 * @author BananaPuncher714
 */
public class Polygon {
    protected List< Point > points;
    
    public Polygon( List< Point > points ) {
        this.points = points;
    }
    
    public List< Point > getPoints() {
        return points;
    }
    
    public double area() {
        double area = 0;
        for ( int i = 0; i < points.size(); ++i ) {
            final Vector2d a = new Vector2d( points.get( i ) );
            final Vector2d b = new Vector2d( points.get( ( i + 1 ) % points.size() ) );
            area += a.cross( b );
        }
        return Math.abs( area ) / 2.0;
    }
}