Rotating Arcs Sketch in Ruby Processing

Here is vanilla sketch that wasn't easy to translate to ruby, the more hacks there are, the harder it is to translate. However conversely it should make me a bit bit more sensitive to the same issue in reverse. The original sketch featured sincos look up tables which are a dubious benefit in java, especially when not optimised. It also featured a nasty ++ increment hack. The original sketch had quite lot of casting to int, I found there no casting required in ruby-processing, just a nifty built in deg to radian conversion using a patched Numeric class.

# 
#  Geometry 
#  by Marius Watz. 
#  
load_library 'pdf'
include_package 'processing.pdf'

attr_reader :num, :pt, :style, :dosave

def setup
  size(1024, 768, P3D)
  background(255)
  @dosave = false
  @num = 150
  @pt = []
  @style = []

  # Set up arc shapes
  index = 0
  (0 ... num).each do |i|
    pt.push(rand(TWO_PI)) # Random X axis rotation
    pt.push(rand(TWO_PI)) # Random Y axis rotation

    pt.push(rand(60 .. 80)) # Short to quarter-circle arcs
    if (rand(100)>90)
      pt[pt.length - 1] = rand(8 .. 27) * 10
    end
    pt.push(rand(2 .. 50) * 5) # Radius. Space them out nicely

    pt.push(rand(4 .. 32)) # Width of band
    if (rand(100) > 90)
      pt[pt.length - 1] = rand(40 .. 60) # Width of band
    end

    pt.push(rand(0.005 .. 0.0334))# Speed of rotation

    # get colors
    prob = rand(100)
    if (prob < 30)
      style[i*2] = color_blended(rand, 255,0,100, 255,0,0, 210)
    elsif(prob < 70)
      style[i*2] = color_blended(rand, 0,153,255, 170,225,255, 210)
    elsif(prob<90)
      style[i*2] = color_blended(rand, 200,255,0, 150,255,0, 210)
    else
      style[i*2] = color(255,255,255, 220)
    end

    if (prob < 50)
      style[i*2] = color_blended(rand, 200,255,0, 50,120,0, 210)
    elsif(prob < 90)
      style[i*2] = color_blended(rand, 255,100,0, 255,255,0, 210)
    else
      style[i*2] = color(255, 255, 255, 220)
      style[i*2+1] = rand(100) % 3
    end
  end
end

def draw
  if(dosave)
    # set up PGraphicsPDF for use with beginRaw
    pdf = begin_raw(PDF, "pdf_complex_out.pdf")
    # set default Illustrator stroke styles and paint background rect.
    pdf.stroke_join(MITER)
    pdf.stroke_cap(SQUARE)
    pdf.fill(0)
    pdf.no_stroke
    pdf.rect(0,0, width,height)
  end
  background(0)
  index = 0
  translate(width/2, height/2, 0)
  rotate_x(PI/6)
  rotate_y(PI/6)
  (0 ... num).each do |i|
    push_matrix
    rotate_x(pt[index])
    rotate_y(pt[index + 1])
    index += 2
    if (style[i*2+1] == 0)
      stroke(style[i*2])
      no_fill
      stroke_weight(1)
      arc_line(0,0, pt[index],pt[index + 1],pt[index + 2])
      index += 3
    elsif (style[i*2+1] == 1)
      fill(style[i*2])
      no_stroke
      arc_line_bars(0,0, pt[index],pt[index + 1],pt[index + 2])
      index += 3
    else
      fill(style[i*2])
      no_stroke
      arc(0,0, pt[index],pt[index + 1],pt[index + 2])
      index += 3
    end
    # increase rotation
    pt[index-5] += pt[index] / 10
    pt[index-4] += pt[index] / 20
    index += 1
    pop_matrix
  end
  if (dosave)
    end_raw
    @dosave=false
  end
end


# Get blend of two colors
def color_blended(fract, r, g, b, r2, g2, b2, a)
  r2 = (r2 - r)
  g2 = (g2 - g)
  b2 = (b2 - b)
  return color(r + r2 * fract, g + g2 * fract, b + b2 * fract, a)
end


# Draw arc line
def arc_line(x, y, deg, rad, w)
  a=(deg < 360)? deg : 0
  numlines = w/2
  (0 ... numlines).each do
    begin_shape
    (0 ... a).each do |i|
      vertex(cos(i.radians)*rad+x,sin(i.radians)*rad+y)
    end
    end_shape
    rad += 2
  end
end

# Draw arc line with bars
def arc_line_bars(x, y, deg, rad, w)
  a=(deg < 360)? deg / 4 : 0
  begin_shape(QUADS)
  (0 ... a).step(4) do |i|
    vertex(cos(i.radians)*(rad)+x,sin(i.radians)*(rad)+y)
    vertex(cos(i.radians)*(rad+w)+x,sin(i.radians)*(rad+w)+y)
    vertex(cos((i + 2).radians)*(rad+w)+x,sin((i + 2).radians)*(rad+w)+y)
    vertex(cos((i + 2).radians)*(rad)+x,sin((i + 2).radians)*(rad)+y)
  end
  end_shape
end

# Draw solid arc
def arc(x,y,deg,rad,w)
  a = (deg < 360)? deg : 0
  begin_shape(QUAD_STRIP)
  (0 ... a).each do |i|
    vertex(cos(i.radians)*(rad)+x,sin(i.radians)*(rad)+y)
    vertex(cos(i.radians)*(rad+w)+x,sin(i.radians)*(rad+w)+y)
  end
  end_shape
end

def mouse_pressed
  @dosave = true
end

# 
#  Geometry 
#  by Marius Watz. 
#  
load_library 'pdf'
include_package 'processing.pdf'

attr_reader :num, :pt, :style, :dosave

def setup
  size(1024, 768, P3D)
  background(255)
  @dosave = false
  @num = 150
  @pt = []
  @style = []

  # Set up arc shapes
  index = 0
  (0 ... num).each do |i|
    pt.push(rand(TWO_PI)) # Random X axis rotation
    pt.push(rand(TWO_PI)) # Random Y axis rotation

    pt.push(rand(60 .. 80)) # Short to quarter-circle arcs
    if (rand(100)>90)
      pt[pt.length - 1] = rand(8 .. 27) * 10
    end
    pt.push(rand(2 .. 50) * 5) # Radius. Space them out nicely

    pt.push(rand(4 .. 32)) # Width of band
    if (rand(100) > 90)
      pt[pt.length - 1] = rand(40 .. 60) # Width of band
    end

    pt.push(radians(rand(5 .. 30)) / 5 )# Speed of rotation

    # get colors
    prob = rand(100)
    if (prob < 30)
      style[i*2] = color_blended(rand, 255,0,100, 255,0,0, 210)
    elsif(prob < 70)
      style[i*2] = color_blended(rand, 0,153,255, 170,225,255, 210)
    elsif(prob<90)
      style[i*2] = color_blended(rand, 200,255,0, 150,255,0, 210)
    else
      style[i*2] = color(255,255,255, 220)
    end

    if (prob < 50)
      style[i*2] = color_blended(rand, 200,255,0, 50,120,0, 210)
    elsif(prob < 90)
      style[i*2] = color_blended(rand, 255,100,0, 255,255,0, 210)
    else
      style[i*2] = color(255, 255, 255, 220)
      style[i*2+1] = rand(100).to_i % 3
    end
  end
end

def draw
  if(dosave)
    # set up PGraphicsPDF for use with beginRaw
    pdf = begin_raw(PDF, "pdf_complex_out.pdf")
    # set default Illustrator stroke styles and paint background rect.
    pdf.stroke_join(MITER)
    pdf.stroke_cap(SQUARE)
    pdf.fill(0)
    pdf.no_stroke
    pdf.rect(0,0, width,height)
  end
  background(0)
  index = 0
  translate(width/2, height/2, 0)
  rotate_x(PI/6)
  rotate_y(PI/6)
  (0 ... num).each do |i|
    push_matrix
    rotate_x(pt[index])
    rotate_y(pt[index + 1])
    index += 2
    if (style[i*2+1] == 0)
      stroke(style[i*2])
      no_fill
      stroke_weight(1)
      arc_line(0,0, pt[index],pt[index + 1],pt[index + 2])
      index += 3
    elsif (style[i*2+1] == 1)
      fill(style[i*2])
      no_stroke
      arc_line_bars(0,0, pt[index],pt[index + 1],pt[index + 2])
      index += 3
    else
      fill(style[i*2])
      no_stroke
      arc(0,0, pt[index],pt[index + 1],pt[index + 2])
      index += 3
    end
    # increase rotation
    pt[index-5] += pt[index] / 10
    pt[index-4] += pt[index] / 20
    index += 1
    pop_matrix
  end
  if (dosave)
    end_raw
    @dosave=false
  end
end


# Get blend of two colors
def color_blended(fract, r, g, b, r2, g2, b2, a)
  r2 = (r2 - r)
  g2 = (g2 - g)
  b2 = (b2 - b)
  return color(r + r2 * fract, g + g2 * fract, b + b2 * fract, a)
end


# Draw arc line
def arc_line(x, y, deg, rad, w)
  a=(deg < 360)? deg : 0
  numlines = w/2
  (0 ... numlines).each do
    begin_shape
    (0 ... a).each do |i|
      vertex(cos(radians(i))*rad+x,sin(radians(i))*rad+y)
    end
    end_shape
    rad += 2
  end
end

# Draw arc line with bars
def arc_line_bars(x, y, deg, rad, w)
  a=(deg < 360)? deg / 4 : 0
  begin_shape(QUADS)
  (0 ... a).step(4) do |i|
    vertex(cos(radians(i))*(rad)+x,sin(radians(i))*(rad)+y)
    vertex(cos(radians(i))*(rad+w)+x,sin(radians(i))*(rad+w)+y)
    vertex(cos(radians(i + 2))*(rad+w)+x,sin(radians(i + 2))*(rad+w)+y)
    vertex(cos(radians(i + 2))*(rad)+x,sin(radians(i + 2))*(rad)+y)
  end
  end_shape
end

# Draw solid arc
def arc(x,y,deg,rad,w)
  a = (deg < 360)? deg : 0
  begin_shape(QUAD_STRIP)
  (0 ... a).each do |i|
    vertex(cos(radians(i))*(rad)+x,sin(radians(i))*(rad)+y)
    vertex(cos(radians(i))*(rad+w)+x,sin(radians(i))*(rad+w)+y)
  end
  end_shape
end

def mouse_pressed
  @dosave = true
end