Mini Factwheels

0-0-100.png

0-100-0.png

0-2-0.png

10-3-0.png

100-0-0.png

10000-8-13.png

11-2-0.png

11-4-8.png

182-119-1205.png

2-1-0.png

4-2-8.png

6-4-2.png

7-0-0.png

7-2-0.png

7839-8009-3041.png

9-3-0.png

blank.png

miniwheel.rb

# Made by @markijbema, based on @joelkuiper's SVG Factwheel

require 'rvg/rvg'

include Magick
include Math

class SvgWheelBuilder
  def initialize(
        percentages_max_colors=['#98d100', '#36A9E1', '#E94E1B'],
        percentages_colors=['#dbeab3','#c5eaf8','#f8caba'], #  green blue red
        disabled_color = '#dadada'
      )
      #sanity check, if the color is in the wrong format imagemagick crashes in mysterious ways
      [percentages_max_colors, percentages_colors, [disabled_color]].each do |colors|
        colors.each do |color|
          unless color =~ /^#[a-fA-F0-9]{6}$/
            raise "Color should be in #xxxxxx format"
          end
        end
      end
      @disabled_color = disabled_color
      @percentages_colors = percentages_colors
      @percentages_max_colors = percentages_max_colors
  end

  def wheel(percentages)
    RVG::Group.new do |canvas|
      had = 0;
      percentages.each_with_index do |percentage, index|
        if percentage == percentages.max
          stroke = @percentages_max_colors[index]
        else
          # stroke = @percentages_colors[index]
            stroke = @disabled_color
        end
        canvas.path(arc_path(percentage,had,6)).styles(:fill => 'none', :stroke => stroke, :stroke_width => 4)
        had += percentage
      end
    end
  end

  def string_for_float(f)
    ("%0.5f"%f).sub(/^-(0.0+)$/, '\1')
  end

  def arc_path(percentage, percentage_offset, radius)
    large_angle = percentage > 50

    start_angle = percentage_offset                * 2*Math::PI / 100
    end_angle   = (percentage_offset + percentage) * 2*Math::PI / 100

    start_x =   radius * Math.cos(start_angle)
    start_y = - radius * Math.sin(start_angle)
    end_x   =   radius * Math.cos(end_angle)
    end_y   = - radius * Math.sin(end_angle)

    path_string(start_x,start_y, end_x, end_y, large_angle, radius)
  end

  def path_string(start_x, start_y, end_x, end_y, large_angle, radius)
    start_x = string_for_float(start_x)
    start_y = string_for_float(start_y)
    end_x   = string_for_float(end_x)
    end_y   = string_for_float(end_y)

    return [['M',start_x,start_y],
            ["A", radius, radius, 0, large_angle ? 1 : 0,  0, end_x, end_y]].flatten.join(' ')
  end

end


class PercentageFormatter

  def initialize(round_to, minimum)
    @round_to = round_to
    @minimum = minimum
  end

  DOUBT_INDEX = 1

  def floor_percentages(percentages)
    percentages.map {|x| ((x.to_f / @round_to )).floor.to_i * @round_to }
  end

  def cap_percentages(percentages)
    round_to = @round_to
    minimum = @minimum

    after_total, large_ones = 0.0, 0.0
    percentages.each do |percentage|
      after_total += [percentage, minimum].max
      if percentage > (100 - minimum)/2
        large_ones += percentage
      end
    end
    too_much = after_total - 100
    percentages = percentages.map do |percentage|
      if percentage < minimum
        percentage = minimum
      elsif percentage > (100-minimum)/2
        percentage = percentage - percentage/large_ones*too_much
      end
      percentage.round
    end
  end

  def process_percentages(percentages)
    percentages = cap_percentages(percentages)
    percentages = floor_percentages(percentages)
    percentages[DOUBT_INDEX] += 100 - percentages.reduce(0,:+)
    percentages
  end

end
[
  [100, 0, 0],
  [0, 100, 0],
  [0, 0, 100],
  [10000, 8, 13],
  [2, 1, 0],
  [7839, 8009, 3041],
  [182, 119, 1205],
  [4, 2, 8],
  [10, 3, 0],
  [6, 4, 2],
  [11, 2, 0],
  [9, 3, 0],
  [7, 0, 0],
  [0, 2, 0],
  [7, 2, 0],
  [11, 4, 8],
].each do |values|

  total = values.inject{|sum,x| sum + x }
  percentages_wrong_order = values.map{|i| 100*i/total}

  # we denote them in above in green,red,blue format, but the SvgWheelBuilder expects green,blue,red
  percentages = [percentages_wrong_order[0], percentages_wrong_order[2], percentages_wrong_order[1]]

  after_percentages = PercentageFormatter.new(5,15).process_percentages(percentages)

  rvg = RVG.new(20,20).viewbox(0,0,20,20) do |canvas|
    canvas.use(SvgWheelBuilder.new().wheel(after_percentages)).translate(10,10)
  end

  local_path = "#{values.join('-')}.png"
  rvg.draw.write(local_path)
end