circle_grid.rb

# Circle Grid
# https://picasaweb.google.com/adam.bachman/LivecodePractice20100618
require 'ostruct'

class CircleGrid < Processing::App
  def setup
    background 255
    ellipse_mode CENTER
    stroke_width 20
    frame_rate 30
    no_cursor

    @step = 64
    @c = []
    @min = 20
    @max = 200
    (0..width).step(@step).each do |x|
      (0..height).step(@step).each do |y|
        c = OpenStruct.new
        c.x = x
        c.y = y
        c.dr = random(1,50)
        c.r = random(@min, @max)
        c.c = color(0, # random(0, 100),
                    random(100, 200),
                    0) # random(100))
        @c << c
      end
    end
    @keys = {}
  end

  def draw
    no_stroke
    fill 255, 20
    rect 0, 0, width, height
    no_fill
    stroke 0

    @c.each do |c|
      # update
      c.r += c.dr
      if c.r < @min || c.r > @max
        c.dr *= -1
      end
      # draw
      dx = (mouse_x - c.x).abs
      dy = (mouse_y - c.y).abs
      # auto
      if @keys[' ']
        stroke c.c # , map(c.r, @min - 51, @max, 0, 100)
        ellipse c.x, c.y, c.r, c.r
      else
        # mouse
        stroke 200 - c.r, 255- c.r, c.r
        ellipse c.x, c.y, dx, dy
      end
    end
  end

  def key_pressed
    @keys[key] = true
  end
  def key_released
    @keys[key] = false
  end

  def mouse_pressed
    save_frame "20100618/#{ Time.now.to_i }.png"
  end
end

CircleGrid.new :title => "Circle Grid",
  :width => 640,
  :height => 480