mandelbrot.rb

java_import java.awt.image.BufferedImage
java_import javax.swing.JFrame
 
class Mandelbrot < JFrame
  MAX_ITER, ZOOM = 1200, 350.0

  def initialize
    super("Mandelbrot Set")
    setBounds(100, 100, 800, 600)
    setDefaultCloseOperation(EXIT_ON_CLOSE)
    @image = BufferedImage.new(width, height, BufferedImage::TYPE_INT_RGB);
    now = Time.now
    threads = []
    sub_divide = 2 # 2
    (0...height).each_slice(height/sub_divide) do |x|
      (0...width).each_slice(width/sub_divide) do |y|
        threads << Thread.new { render(x, y) }
      end
    end
    p threads.size
    threads.each { |t| t.join }
    p Time.now - now
  end
 
  def paint(g)
    g.drawImage(@image, 0, 0, self);
  end

  def render(h, w)
    h.each do |y|
      w.each do |x|
        zx, zy = 0.0, 0.0
        cX, cY = (x - 400) / ZOOM, (y - 300) / ZOOM
        iter = MAX_ITER
        while (zx * zx + zy * zy < 4 && iter > 0)
          zy, zx = 2.0 * zx * zy + cY, zx * zx - zy * zy + cX
          iter -= 1
        end
        @image.setRGB x, y, iter | (iter << 8)
      end
    end
  end
end
      
 Mandelbrot.new.setVisible(true);