Polyspiral

import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)

/**
 * Write a description of class PolySpiral here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */
public class PolySpiral extends Actor
{
    double inc = 0;
    
    public PolySpiral()
    {
        GreenfootImage gfim = new GreenfootImage(900,600);
        inc = (inc + 0.05) % 360;
        drawSpiral(gfim, 5, Math.toRadians(inc));
        setImage(gfim);
    }
    
    public void drawSpiral(GreenfootImage gfim, int length, double angleIncrement) 
    {
 
        double x1 = gfim.getWidth() / 2;
        double y1 = gfim.getHeight() / 2;
        double angle = angleIncrement;
 
        for (int i = 0; i < 150; i++) {
 
            gfim.setColor(Color.BLUE);//(Color.getHSBColor(i / 150f, 1.0f, 1.0f));
 
            double x2 = x1 + Math.cos(angle) * length;
            double y2 = y1 - Math.sin(angle) * length;
            gfim.drawLine((int) x1, (int) y1, (int) x2, (int) y2);
            x1 = x2;
            y1 = y2;
 
            length += 3;
 
            angle = (angle + angleIncrement) % (Math.PI * 2);
        }
        
    }
}