Playing with Ryan's Graphics lib

modulo_arithmetic_1.rb

# https://vimeo.com/192116528
require "graphics"

class Clock < Graphics::Simulation
  def initialize
    @radius         = 400
    @margin         = 20
    @increment_rate = 0.0009
    @num_lines      = 1600
    @line_width     = 2
    @start_num      = (@num_lines/2.0)-1
    @finish_num     = (@num_lines/3.0)+1
    super 1440, 900
    color.default_proc = -> h, k { k }
  end

  def draw(iteration)
    clear
    multiplier = @start_num + (@finish_num-@start_num)*progress(iteration)
    # p time: Time.now.strftime('%H:%M:%S'), progress: progress(iteration)
    @num_lines.times do |index|
      percent = index.to_f / @num_lines
      start   = CIRCUMFERENCE * percent
      finish  = start * multiplier
      green   = (Math.cos(start+TILT) * 127.5).to_i + 128
      color   = rgba 255, green, 0 # omitting blue for now b/c https://github.com/zenspider/graphics/issues/23
      line x(start), y(start), x(finish),   y(finish), color
      line x(start), y(start), x(finish), 1+y(finish), color # thicken the line a bit
    end
  end

  private

  CIRCUMFERENCE = 2 * Math::PI
  TILT = Math::PI

  def x(rad, radius: @radius, x_mid: w/2)
    Math.cos(rad) * radius + x_mid
  end

  def y(rad, radius: @radius, y_mid: h/2)
    Math.sin(rad) * radius + y_mid
  end

  def rgba(r, g, b, a=255)
    screen.format.map_rgba(r.to_i, g.to_i, b.to_i, a.to_i)
  end

  # This function determines how quickly we move through the different parts of the animation
  # Particularly, we want it to move pretty quickly through the middle bits so that it doesn't
  # take 20 minutes to watch, but we also want it to move slowly through the end-points,
  # in order to enjoy the satisfaction of all the lines matching up. I explained the logic
  # of how it works here: http://math.stackexchange.com/a/2019541/258281
  # and an image of this vs sine wave @ https://twitter.com/josh_cheek/status/799520755801268224
  def progress(iteration)
    numerator = Math.sin Math.sin Math.sin iteration*@increment_rate
    @progress_denominator ||= Math.sin Math.sin 1
    0.5 + (numerator / @progress_denominator) / 2
  end
end

Clock.new.run if $0 == __FILE__

modulo_arithmetic_2.rb

# https://vimeo.com/192214982
require "graphics"

class Clock < Graphics::Simulation
  def initialize
    @radius         = 400
    @margin         = 20
    @increment_rate = 0.005
    @num_lines      = 1600
    @start_num      = (@num_lines/2.0)-1 # interesting points in the progression
    @finish_num     = (@num_lines/3.0)+1 # emphasize them by turning around at them
    super 1440, 900, 24                  # my screen resolution, and 24 bpp (https://github.com/zenspider/graphics/issues/23)
    color.default_proc = -> h, k { k }   # so we don't have to rely on named colours
  end

  def draw(iteration)
    clear
    multiplier = @start_num + (@finish_num-@start_num)*progress(iteration)
    @num_lines.times do |index|
      start   = CIRCUMFERENCE * index.to_f / @num_lines
      finish  = start * multiplier
      line x(start,  x_mid: w/2-@radius*0.7),
           y(start,  y_mid: h/2+@margin),
           x(finish, x_mid: w/2+@radius*0.7),
           y(finish, y_mid: h/2+@margin),
           :white
    end
  end

  private

  CIRCUMFERENCE = 2 * Math::PI

  def x(rad, radius: @radius, x_mid: w/2)
    Math.cos(rad) * radius + x_mid
  end

  def y(rad, radius: @radius, y_mid: h/2)
    Math.sin(rad) * radius + y_mid
  end

  # This function determines how quickly we move through the different parts of the animation
  # Particularly, we want it to move pretty quickly through the middle bits so that it doesn't
  # take 20 minutes to watch, but we also want it to move slowly through the end-points,
  # in order to enjoy the satisfaction of all the lines matching up. I explained the logic
  # of how it works here: http://math.stackexchange.com/a/2019541/258281
  def progress(iteration)
    numerator = Math.sin Math.sin Math.sin iteration*@increment_rate
    @progress_denominator ||= Math.sin Math.sin 1
    0.5 + numerator / @progress_denominator / 2
  end
end

Clock.new.run

modulo_arithmetic_3.rb

# https://vimeo.com/192217151
require "graphics"

class Clock < Graphics::Simulation
  def initialize
    @radius         = 400
    @margin         = 20
    @increment_rate = 0.005
    @num_lines      = 1600
    @start_num      = 0
    @finish_num     = 2*@num_lines
    super 1440, 900, 24                  # my screen resolution, and 24 bpp (https://github.com/zenspider/graphics/issues/23)
    color.default_proc = -> h, k { k }   # so we don't have to rely on named colours
  end

  def draw(iteration)
    clear
    multiplier = @start_num + (@finish_num-@start_num)*progress(iteration)
    @num_lines.times do |index|
      percent = index.to_f / @num_lines
      start   = CIRCUMFERENCE * percent
      finish  = start * multiplier
      blue    = (Math.cos(start) * 127.5).to_i + 128
      green   = (Math.sin(start) *  50.5).to_i + 128
      red     = 255 - blue
      color   = rgba red, green, blue

      line x(start,  x_mid: w/2,             radius: @radius),
           y(start,  y_mid: h/2+@margin,     radius: @radius),
           x(finish, x_mid: w/2+@radius*0.5, radius: @radius*0.25),
           y(finish, y_mid: h/2+@radius*0.5, radius: @radius*0.25),
           color
    end
  end

  private

  CIRCUMFERENCE = 2 * Math::PI

  def x(rad, radius: @radius, x_mid: w/2)
    Math.cos(rad) * radius + x_mid
  end

  def y(rad, radius: @radius, y_mid: h/2)
    Math.sin(rad) * radius + y_mid
  end

  def rgba(r, g, b, a=255)
    screen.format.map_rgba(r.to_i, g.to_i, b.to_i, a.to_i)
  end

  # This function determines how quickly we move through the different parts of the animation
  # Particularly, we want it to move pretty quickly through the middle bits so that it doesn't
  # take 20 minutes to watch, but we also want it to move slowly through the end-points,
  # in order to enjoy the satisfaction of all the lines matching up. I explained the logic
  # of how it works here: http://math.stackexchange.com/a/2019541/258281
  def progress(iteration)
    numerator =               Math.sin Math.sin Math.sin Math.sin Math.sin Math.sin Math.sin Math.sin Math.sin Math.sin Math.sin Math.sin iteration*@increment_rate
    @progress_denominator ||= Math.sin Math.sin Math.sin Math.sin Math.sin Math.sin Math.sin Math.sin Math.sin Math.sin Math.sin 1
    0.5 + numerator / @progress_denominator / 2
  end
end

Clock.new.run