Towards a zoom-able mandelbrot ruby-processing

Working toward a zoom-able mandelbrot (albeit somewhat speed limited in ruby-processing)

Parameter = Struct.new(:cx, :cy, :ch, :cw) # required for future

RATIO = 1.336
TMAX = 5_000

attr_reader :current, :default # required for future work

def setup
  size(534, 400, P2D)
  @default = Parameter.new(-0.53 - (1.4 * RATIO), -1.4, 2.8, 2.8 * RATIO)
  @current = default
  load_pixels
  no_fill
  stroke(255)
  create_mandelbrot(width, height)
  no_loop
end

def create_mandelbrot(w, h)
  y_zero = ->(y, param) { y * param.ch / height + param.cy }
  x_zero = ->(x, param) { x * param.cw / width + param.cx }
  h.times do |j|
    y0 = y_zero.call(j, current)
    w.times do |k|
      x0 = x_zero.call(k, current)
      x, y = 0, 0
      xsqr, ysqr = 0.0, 0.0
      t = 0
      while t < TMAX && (xsqr + ysqr < 4.0)
        y = x * y
        y += y + y0
        x = xsqr - ysqr + x0
        xsqr = x * x
        ysqr = y * y
        t += 1
      end
      if t < TMAX
        smth = t - Math.log(xsqr + ysqr)
        pixels[k + j * width] = Java::JavaAwt::Color.HSBtoRGB(smth / 500, 0.8, 0.9)
      else
        pixels[k + j * width] = 0
      end
    end
  end
  update_pixels
end

Lorenz Attractor Ruby-Processing

Here is a processing sketch that used a LinkedList (not needed in ruby version, an array is sufficient)

LENGTH = 10_000
SPEED = 10

load_library 'vecmath'

attr_accessor :particles, :a, :b, :c, :d

def setup
  size 512, 512, P3D
  ArcBall.init(self)
  frame_rate 30
  stroke color(0, 0, 0, 33)
  stroke_weight 2
  @a = 10
  @b = 28
  @c = 8 / 3
  @d = 0.75
  init_particles
end

def draw
  background(255)
  advance_particles(SPEED)
  draw_particles
end

def init_particles
  @particles = []
  LENGTH.times do
    add_particle(Vec3D.new 1.5, -1.5, 1.5) # need to start somewhere
  end
end

def add_particle(p)
  step = Vec3D.new(a * (p.y - p.x), p.x * (b - p.z) - p.y, p.x * p.y - c * p.z)
  step *= (d / step.mag)
  particles << p + step
end

def advance_particles(count)
  (1..count).each do
    particles.shift
    add_particle(particles.last)
  end
end

def draw_particles
  scale(8)
  particles.each_cons(2) do |a, b|
    stroke(color((b.x - a.x) * 255, (b.y - a.y) * 255, (b.z - a.z) * 255, 88))
    line(a.x, a.y, a.z - 30, b.x, b.y, b.z - 30)
  end
end

Reading and writing to a csv file ruby-processing (version two)

I find it really surprising that one of most popular posts for ruby-processing is the original version here is an alternative slightly cleaner version:-

#
# Loading Tabular Data
# after Daniel Shiffman, by Martin Prout.
#
# This example demonstrates how to use CSV
# to retrieve data from a CSV file and make objects
# from that data.
#
# Here is what the CSV looks like:
#
#   x,y,diameter,name
#   160,103,43.19838,Happy
#   372,137,52.42526,Sad
#   273,235,61.14072,Joyous
#   121,179,44.758068,Melancholy
#
require 'csv'

load_library 'bubble'

attr_reader :bubbles, :data

def setup
  size(640, 360)
  load_data
end

def draw
  background(255)
  # Display all bubbles
  bubbles.run
  text_align(LEFT)
  fill(0)
  text('Click to add bubbles.', 10, height - 10)
end

def load_data
  # Load CSV file into an Array of Hash objects
  # headers: option indicates the file has a header row
  @bubbles = BubbleData.new
  CSV.foreach('data/data.csv', headers: true) do |row|
    x = row['x'].to_f
    y = row['y'].to_f
    d = row['diameter'].to_f
    n = row['name']
    # Make a Bubble object out of the data read
    bubbles << Bubble.new(x, y, d, n)
  end
end

def mouse_pressed
  bubbles << Bubble.new(mouse_x, mouse_y, rand(40..80), 'blah')
  # If there are more than 10 bubbles delete the oldest bubble
  bubbles.shift if bubbles.size > 10
  # Writing the csv data back to the same file, (also specify UTF-8 format)
  CSV.open('data/data.csv', 'w:UTF-8') do |csv|
    csv << %w(x y diameter name) # create csv headers
    bubbles.each do |bubble|
      csv << bubble.to_a       # write back bubble data
    end
  end
  # And reloading it
  load_data
end

# A run module
module Runnable
  def run
    each(&:display)
    each { |item| item.rollover(mouse_x, mouse_y) }
  end
end

# Enumerable class holds bubble data
class BubbleData
  extend Forwardable
  def_delegators(:@bubbles, :each, :<<, :size, :shift)
  include Enumerable, Runnable

  def initialize
    @bubbles = []
  end
end

Experimenting with jruby-complete-SNAPSHOT-9.0.0.0 and ruby processing

Anyone wishing to explore ruby-2.1+ syntax with ruby-processing should get hold of jruby-complete-SNAPSHOT-9.0.0.0.jar (compile it yourself) rename the jar to jruby-complete.jar and manually replace the jruby-complete.jar in the ruby-processing gem (lives in lib/ruby folder). Gems typically live in .gem/ruby/2.1.0/gems folder depending on your system unless you use rvm or other such nasty stuff. To ensure jruby-complete use add 'JRUBY: false' to your ~/.rp5rc settings (or use the --nojuby flag). Also use watch rather than run to run sketches (to avoid the failure in draw loop bug). Here is a sketch I posted earlier using 2.1 syntax, but here I explore using 'format' to present rationals....
After experimentation you can easily restore the original jruby-complete by running 'rp5 setup install' (no download required since we keep copy of the original in the vendors folder).

def setup
  size 640, 250
  background 10
  f = createFont("Arial", 24, true)
  third = 1 / 3r     # since ruby 2.1.0
  quarter = 1 / 4r
  add = format("%s + %s = %s", third, quarter, third + quarter)
  subtract = format("%s - %s = %s", third, quarter, third - quarter)
  multiply = format("%s * %s = %s", third, quarter, third * quarter)
  text_font(f, 24)
  fill(220)
  text("Math blackboard ruby-processing", 80, 50)
  text(add, 110, 100)
  text(subtract, 110, 150)
  text(multiply, 110, 200)
end

PS: this one of the sketches not affected by draw loop bug. May'be we don't need to wait too long for a preview version?

@aselder Rough timeframe for a final is hopefully end of January. Will attempt a preview after MRI 2.2 is out.

— Charles Nutter (@headius) December 16, 2014