Utility.java

import greenfoot.*;

/**
 * This is Mr.Cohen's Utility Class
 *
 * @author (your name)
 * @version (a version number or a date)
 */
public class Utility {
  /** density should be 1-100. 100 will be almost completely white */
  public static GreenfootImage drawStorm(int width, int height, int density) {

    Color[] swatch = new Color[64];
    int red = 70;
    int blue = 192;

    // Build a color pallete out of shades of near-white yellow and near-white blue
    for (int i = 0; i < swatch.length / 2; i++) { // first half blue tones
      swatch[i] = new Color(red, 240, 255);
      red += 2;
    }
    for (int i = swatch.length / 2; i < swatch.length; i++) { // second half yellow tones
      swatch[i] = new Color(255, 255, blue);
      blue++;
    }

    // The temporary image, my canvas for drawing
    GreenfootImage temp = new GreenfootImage(width, height);

    // Run this loop one time per "density"

    for (int i = 0; i < density * 50; i++) {
      for (int j = 0; j < 100; j++) { // draw 100 circles
        int randSize;
        // Choose a random colour from my swatch, and set its tranparency randomly
        int randColor = Greenfoot.getRandomNumber(swatch.length);
        int randTrans = Greenfoot.getRandomNumber(220) + 35; // around half transparent
        temp.setColor(swatch[randColor]);

        // setTransparency(randTrans);
        // random locations for our dot
        int randX = Greenfoot.getRandomNumber(width);
        int randY = Greenfoot.getRandomNumber(height);

        int tempVal = Greenfoot.getRandomNumber(250);
        if (tempVal >= 1) {
          // randSize = 2;
          temp.drawRect(randX, randY, 0, 0);
        } else {
          randSize = Greenfoot.getRandomNumber(2) + 2;
          temp.fillOval(randX, randY, randSize, randSize);
        }
        // silly way to draw a dot..
      }
    }

    return temp;
  }
}