gistfile1.rb

class Array; def sum; inject( nil ) { |sum,x| sum ? sum+x : x }; end; end

require 'ruby-processing'

class PieChart        
  include Processing::Proxy     
  include Math
  
  attr_accessor :colors
  
  def initialize(data, options)
    
    # Setup coordinates for display.
    @x = options[:coords][:x]
    @y = options[:coords][:y]
    @radius = options[:radius]
    
    @data = data    
    @data_sum = 0.0
    @duration = 20
    @current = 0
    @rotation = random(PI * 2, PI * 4) 
    @drawRadius = 0
    
    @dataRad = []
    @data_sum = @data.sum             
    
    @data.each do |item|
      @dataRad << item / @data_sum * 360
    end 
    @font = createFont "LeagueGothic", 40
    
  end
  
  def render
    @current += (@duration - @current) * 0.1
    @rotation += ((-PI / 2) - @rotation) * 0.05
    @drawRadius += (@radius - @drawRadius) * 0.2
    
    displayPercentage = (@data[0] / @data_sum * 100 * @current / @duration).to_i
    pushMatrix
    translate @x, @y      
    rotateZ @rotation

    lastAng = 0
    @dataRad.each do |i|
      r = radians(i) * @current / @duration
      fill 100, 10
      noStroke
      arc 0, 0, @drawRadius * 2 + 10, @drawRadius * 2 + 10, lastAng, lastAng + r
      lastAng += r
    end 
    
    lastAng = 0
    @dataRad.each_with_index do |measurement, index|
      r = radians(measurement) * @current / @duration

      if index == 0
        fill color(hue(@colors[0]), saturation(@colors[0]), 80)        
      else
        fill color(hue(@colors[0]), saturation(@colors[0]), 40)
      end
      noStroke
      arc(0, 0, @drawRadius*2, @drawRadius*2, lastAng, lastAng + r)
      lastAng += r
    end
    rotateZ(-@rotation)
    textAlign CENTER
    textFont @font, 48
    fill 100
    text "#{displayPercentage}%", 0, 16   
    popMatrix
    
  end
  
end