// StringFlying.java
// Draw String Image and Free Running
// by nagatani@eken.phys.nagoya-u.ac.jp

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

public class StringFlying implements SGObject {

	int	xWindow,	yWindow;
	
	public	Image	imageString;
	int	xImage,	yImage;
	
	double	xR,	yR,	xP,	yP,	xW,	yW;
	
	boolean	bFirstUse = true;
	int	nMode;
	double	t;
	
	StringFlying (Image imageString, Applet applet) {
		
		this.imageString = imageString;
		this.xWindow = applet.size().width;
		this.yWindow = applet.size().height;
		
		int	xImage = 50,	yImage = 50;	// Default Image Size
		for (int n = 0 ; n < 10 ; n++) {
			int	x = imageString.getWidth (applet),
				y = imageString.getHeight (applet);
			if (x > 0 && y > 0 ) {
				xImage = x;
				yImage = y;
				break;
			}
			try {
				Thread.sleep (10);	// 10 ms Delay Time
			}
			catch (InterruptedException e) {}
		}
		this.xImage = xImage;
		this.yImage = yImage;
		
		nMode = 0;
	}
	
	public void paint (Graphics g, Applet applet) {
		
		if (nMode == 1 && t != 0.0) {
			g.drawImage (imageString,
				     (int) xP, (int) yP,
				     (int) xW, (int) yW,
				     applet);
			// g.setColor (Color.white);
			// g.drawRect ((int) xP, (int) yP,
			//	       (int) xW, (int) yW);
		}
	}
	
	public void move () {
		
		if (nMode == 0) {	// Reset & Initializing Mode
			
			double	theta = Math.random () * 2.0 * Math.PI;
			xR = 1.5 * xWindow/2 * Math.cos (theta);
			yR = 1.5 * yWindow/2 * Math.sin (theta);
			
			if (bFirstUse)
				t = Math.random ();
			else
				t = 0.0;
			bFirstUse = false;
			nMode ++;
			return;
		}
		if (nMode == 1) {	// Displaying Mode
			
			double	T = t*t*t;
			xW = T * xImage * 1.5;
			yW = T * yImage * 1.5;
			double	xCenter = xWindow/2 + T * xR,
				yCenter = yWindow/2 + T * yR;
			xP = xCenter - xW / 2;
			yP = yCenter - yW / 2;
			
			t += 0.01;
			if (t >= 1.0) {
				t = 0.0;
				nMode ++;
			}
			return;
		}
		if (nMode == 2) {	// Sleeping Mode
			t += 0.01;
			if (t >= 0.0) {
				t = 0.0;
				nMode = 0;
			}
			return;
		}
	}
}