// Poly.java
// 2-Dimensional Polygon Manipuration Class
// ２次元 多角形 変形&描画 クラス
// Copyright (C) 1996, 1997 Y.Nagatani
// nagatani@eken.phys.nagoya-u.ac.jp

import java.applet.*;
import java.awt.*;

public class Poly {
	public Applet	parent;
	public int	width, height;
	public int	points;
	public double	x[],	y[];
	public double	x0,	y0,	scale,	rotate;
	public Color	color;
	
 	Poly (Applet parent, int width, int height, int points) {
		
 		this.parent = parent;
		this.width  = width;
		this.height = height;
		this.points = points;
		x = new double[points];
		y = new double[points];
		for (int n = 0 ; n < points ; n++) {
			double	arg = 2.0 * Math.PI * n / points;
			setForm (n, 0.5 * Math.cos(arg),
				   -0.5 * Math.sin(arg));
		}
		setTranslate (0.5, 0.5);
		setScale (0.8);
		setRotate (0);
		color = Color.black;
	}
	public void paint (Graphics g) {
		
		int	X[] = new int[points],
			Y[] = new int[points];
		double	sin = Math.sin (rotate),
			cos = Math.cos (rotate);
		for (int n = 0 ; n < points ; n++) {
			double	x1 =   cos * x[n] + sin * y[n],
				y1 = - sin * x[n] + cos * y[n];
			X[n] = (int) ((x0 + scale * x1) * width);
			Y[n] = (int) ((y0 + scale * y1) * height);
		}
		
		g.setColor (color);
		g.fillPolygon (X, Y, points);
	}
	public void setForm (int point, double x, double y) {
		
		if (0 <= point && point < points) {
			this.x[point] = x;
			this.y[point] = y;
		} else {
			System.out.println ("Poly: Point Domain Error\n");
		}
	}
	public void setTranslate (double x0, double y0) {
		
		this.x0 = x0;
		this.y0 = y0;
	}
	public void setScale (double scale) {
		
		this.scale = scale;
	}
	public void setRotate (double rotate) {
		
		this.rotate = rotate;
	}
	public void setColor (Color color) {
		
		this.color = color;
	}
}