설명이라든가

살아보자

import java.awt.Color
import java.awt.image.BufferedImage
import java.io.File
import java.util.Random
import javax.imageio.ImageIO

class Fern {
  def W1x = { x, y -> 0.836 * x + 0.044 * y }
  def W1y = { x, y -> -0.044 * x + 0.836 * y + 0.169 }
  def W2x = { x, y -> -0.141 * x + 0.302 * y }
  def W2y = { x, y -> 0.302 * x + 0.141 * y + 0.127 }
  def W3x = { x, y -> 0.141 * x - 0.302 * y }
  def W3y = { x, y -> 0.302 * x + 0.141 * y + 0.169 }
  def W4x = { x, y -> 0 }
  def W4y = { x, y -> 0.175337 * y }

  def drawer
  def rnd

  Fern() {
    rnd = new Random()
  }

  def f(k, x, y) {
    if (0 < k) {
      f(k - 1, W1x(x, y), W1y(x, y))
      if (rnd.nextDouble() < 0.3)
        f(k - 1, W2x(x, y), W2y(x, y))
      if (rnd.nextDouble() < 0.3)
        f(k - 1, W3x(x, y), W3y(x, y))
      if (rnd.nextDouble() < 0.3)
        f(k - 1, W4x(x, y), W4y(x, y))
    } else {
      drawer(x, y)
    }
  }

  def sprout(n, clos) {
    drawer = clos
    f(n, 0, 0)
  }
}

class FernCanvas {
  def width
  def height
  def allowed
  def img
  def fernColor = new Color(0.0F, 0.5F, 0.0F)

  FernCanvas(size, padding) {
    width = size
    height = size
    allowed = size - padding
    img = new BufferedImage(
            width, height, BufferedImage.TYPE_INT_RGB)
    def g = null
    try {
        g = this.img.createGraphics()
        g.setColor(Color.WHITE)
        g.fillRect(0, 0, width, height)
    } finally {
        if (g != null) {
            g.dispose()
        }
    }
  }

  def plot(x, y) {
    def plotX = (int)( x * allowed + width * 0.5)
    def plotY = (int)( height - y * allowed)
    img.setRGB(plotX, plotY, fernColor.getRGB())
  }

  def save_png_to(fileName) {
    ImageIO.write(img, "PNG", new File(fileName));
  }
}

def N = 20

canvas = new FernCanvas(500, 10)
new Fern().sprout(N) { x, y ->
  canvas.plot(x, y)
}
canvas.save_png_to("fern.png")

내면서