create-picture.rb

require 'rubygems'
require 'RMagick'
require 'rvg/rvg'
include Magick

require 'picture'

RVG::dpi = 72

class PictureGenerator

  def initialize(input, add_text=true, blur_amount=2)
    @input = input
    @picture = Picture.new(@input)
    @size = @picture.size
    @add_text = add_text
    @blur_amount = blur_amount
  end

  def generate_picture
    rvg = generate_rvg
    rvg = render_rvg(rvg)
    rvg = blur_rvg(rvg, @blur_amount) unless @blur_amount == 0
    save_picture(rvg)

    message 'Done!'
  end

  private

  def generate_rvg
    message "Generating picture \"#{@input}\" containing #{@picture.boxes.size} boxes, size #{@size}x#{@size} ..."

    RVG.new(@size, @size).viewbox(0, 0, @size, @size) do |canvas|
      add_background(canvas)
      add_boxes(canvas)
      add_text(canvas) if @add_text
    end
  end

  def add_background(canvas)
    canvas.background_fill = @picture.background_colour
  end

  def add_boxes(canvas)
    @picture.boxes.each do |box|
      add_box(canvas, box)
    end
  end

  def add_box(canvas, box)
    canvas.g.translate(box.x, box.y) do |shape|
      shape.rect(box.width, box.height).styles(
        :fill=> box.colour,
        :fill_opacity => box.opacity,
        :stroke => box.stroke_colour,
        :stroke_width => box.stroke_width,
        :stroke_opacity => box.stroke_opacity)
    end
  end

  def add_text(canvas)
    message "Adding input text ..."
    canvas.text(@size / 2, @size - 100) do |title|
      title.tspan(@input).styles(
        :text_anchor => 'middle',
        :font_size => @size / 7,
        :font_family => 'helvetica',
        :font_weight => 900,
        :fill => 'white',
        :stroke => 'black',
        :stroke_width => @size / 100,
        :opacity => 0.2,
        :stroke_opacity => 0.05)
    end
  end

  def render_rvg(rvg)
    message "Rendering ..."
    rvg.draw
  end

  def blur_rvg(rvg, amount)
    message "Adding blur with radius #{amount} ..."
    rvg.blur_image(amount, amount)
  end

  def save_picture(rvg)
    message 'Saving picture ...'
    rvg.write("output/#{@input.gsub(/[^\w|#|@|_]+/, '-')}.png")
  end

  def message(msg)
    puts
    puts msg
  end

end