import java.awt.*;
import java.awt.image.*;

public class Pts{

	//
	// len
	//
	public static int len_se(int p, int sta, int end){
		if(p<sta) return sta-p;
		if(end<p) return p-end;
		return 0;
	}
	public static int len(int p, int sta, int len){
		return len_se(p, sta, sta+len);
	}
	public static double len2(Point p){
		return nai(p,p);
	}
	public static double len(Point p){
		return Math.sqrt(len2(p));
	}
	public static double len(Point a, Point b){
		return len(sub(a,b));
	}
	public static double len(Point p, Point line_sta, Point line_end){
		Point line_v = sub(line_end, line_sta);
		Point t = sub(p, line_sta);
		Point argV = getArgV(line_v, t);
		double argVsz = len(argV);
		if(argVsz == 0) return 0;
		return len(t)*argV.y/argVsz;
		/*
		Point v = sub(line_end, line_sta);
		double vv = len2(v);
		if(vv==0) return 0;
		Point w = sub(p, line_sta);
		return len(sub(w, mul(nai(v,w), v))) / vv;
		*/
	}

	//
	// calc
	//
	public static int sign(int x){
		return x>0 ? 1 : (x<0 ? -1 : 0);
	}
	public static Point sign(Point p){
		return new Point(sign(p.x), sign(p.y));
	}
	public static Point add(Point a, Point b){
		return new Point(a.x+b.x, a.y+b.y);
	}
	public static Point sub(Point a, Point b){
		return new Point(a.x-b.x, a.y-b.y);
	}
	public static Point mul(double n, Point p){
		return new Point((int)(n*p.x), (int)(n*p.y));
	}
	public static Point mul(Point p, double n){
		return mul(n, p);
	}
	public static Point cen(Point a, Point b){
		return mul(0.5, add(a,b));
	}
	public static Point cen(Dimension sz){
		return new Point(sz.width/2,sz.height/2);
	}
	public static double nai(Point a, Point b){
		return a.x*b.x + a.y*b.y;
	}

	// ratio 0.0: a, ratio 1.0:b
	public static Point ratioPt(Point a, Point b, double ratio){
		return add(mul(a,1-ratio),mul(b,ratio));
	}

	//
	// rot
	//
	public static Point rot(Point v, double rad){
		int r = 10000;
		Point argV = new Point(
			(int)(r*Math.cos(rad)),
			(int)(r*Math.sin(rad))
		);
		return rotMul(v, argV);
		/*
		double s = Math.sin(rad);
		double c = Math.cos(rad);
		return new Point(c*v.x-s*v.y, s*v.x+c*v.y);
		*/
	}
	public static Point rotP90(Point v){
		return new Point(-v.y, v.x);
	}
	public static Point rot180(Point v){
		return new Point(-v.x, -v.y);
	}
	public static Point rotN90(Point v){
		//return rot180(rotP90(v));
		return new Point(v.y, -v.x);
	}
	public static Point rev(Point v){
		return new Point(v.x, -v.y);
	}
	public static Point exch(Point v){
		//return rotP90(rev(v));
		return new Point(v.y, v.x);
	}

	public static Point rotMul(Point p, Point v){
		return new Point((int)nai(rev(v), p), (int)nai(exch(v), p));
	}
	public static Point rot(Point p, Point v){
		double vl = len(v);
		if(vl==0) return null;
		return mul(rotMul(p,v), 1/vl);
	}
	public static Point getArgV(Point prevV, Point nextV){
		//return rotMul(prevV, rev(nextV)); // NG
		return rotMul(rev(prevV), nextV);
	}
	public static Point rot(Point p, Point prevV, Point nextV){
		return rot(p, getArgV(prevV,nextV));
	}
	public static Point rotoff(Point p, Point o, Point v){
		return add(rot(sub(p,o),v),o);
	}
	public static Point rotoff(Point p, Point o, Point prevV, Point nextV){
		return add(rot(sub(p,o),prevV,nextV),o);
	}	

	//
	// draw
	//
	public static void line(Graphics g, Point a, Point b){
		g.drawLine(a.x,a.y,b.x,b.y);
	}
	public static void drawImage(Graphics g, Image img, Point p, ImageObserver obs){
		g.drawImage(img, p.x,p.y, obs);
	}

	//
	// cast
	//
	public static Point p(Dimension sz){
		return new Point(sz.width, sz.height);
	}
	public static Dimension sz(Point p){
		return new Dimension(p.x,p.y);
	}
	public static Point p(Polygon pl, int i){
		if(i>=pl.npoints) return null;
		return new Point(pl.xpoints[i], pl.ypoints[i]);
	}
	public static void add(Polygon pl, Point p){
		pl.addPoint(p.x, p.y);
	}
}

// EOF