// FireColor.java
// Draw Rolling String
// by nagatani@eken.phys.nagoya-u.ac.jp

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

public class FireColor implements SGObject {

	int	xWindow,	yWindow;
	int	xDelta,		yDelta;
	
	double	t;
	int	nMode;
	
	FireColor (Applet applet) {
		
		this.xWindow = applet.size().width;
		this.yWindow = applet.size().height;
		
		this.xDelta = 5;
		this.yDelta = 5;
		
		nMode  = 0;
		t = 0.0;
	}
	
	public void paint (Graphics g, Applet applet) {
		
		for (int x = 0 ; x < xWindow ; x += xDelta) {
			for (int y = 0 ; y < yWindow ; y += yDelta) {
				double	a = (double) x / xWindow,
					b = (double) y / yWindow;
				
				double	c = + a/2
					    + a * b/2
					    + t*1.73205
					    + a*b*Math.sin (2*Math.PI*t)
					    + 0.05 * Math.sin (8  *Math.PI*a)
						   * Math.sin (8  *Math.PI*b)
						   * Math.sin (8.3*Math.PI*t)
					    + 0.1  * Math.sin (4  *Math.PI*a)
						   * Math.sin (4  *Math.PI*b)
						   * Math.sin (5.1*Math.PI*t)
					    + 0.15 * Math.sin (3  *Math.PI*a)
						   * Math.sin (3  *Math.PI*b)
						   * Math.sin (3.2*Math.PI*t);
				c = c - ((int) c);
				
				g.setColor (Color.getHSBColor
					    ((float)c, 1.0f, 1.0f));
				g.fillRect (x, y, xDelta, yDelta);
			}
		}
	}
	
	public void move () {
		
		if (nMode == 0) {	// Reset Mode
			t = 0.0;
			nMode ++;
			return;
		}
		if (nMode == 1) {	// Displaying Mode
			t += 0.01;
			if (t >= 1.0 && false) {
				t = 0.0;
				nMode ++;
			}
			return;
		}
		if (nMode == 2) {	// Sleeping Mode
			t += 0.01;
			if (t >= 0.01) {
				t = 0.0;
				nMode = 0;
			}
			return;
		}
	}
}