Module: Sass::Script::Functions

Defined in:
lib/sassy_noise/sass_extensions.rb

Overview

Sass implementation of the Noisy jquery plugin: github.com/DanielRapp/Noisy by @philippbosch gist.github.com/1021332

Instance Method Summary collapse

Instance Method Details

#background_noise(kwargs = {}) ⇒ Object 



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# File 'lib/sassy_noise/sass_extensions.rb', line 9

def background_noise(kwargs = {})
  opts = {}
  Sass::Util.map_hash({
      "intensity"  => [0..1,          "",   :Number, Sass::Script::Number.new(0.5) ],
      "opacity"    => [0..1,          "",   :Number, Sass::Script::Number.new(0.08)],
      "size"       => [1..512,        "px", :Number, Sass::Script::Number.new(200) ],
      "monochrome" => [[true, false], "",   :Bool,   Sass::Script::Bool.new(false) ]
    }) do |name, (range, units, type, default)|
    
    if val = kwargs.delete(name)
      assert_type val, type, name
      if range && !range.include?(val.value)
        raise ArgumentError.new("$#{name}: Amount #{val} must be between #{range.first}#{units} and #{range.last}#{units}")
      end
    else
      val = default
    end
    opts[name] = val
  end
  
  image = ChunkyPNG::Image.new(opts["size"].to_i, opts["size"].to_i)
  
  for i in (0..(opts["intensity"].to_s.to_f * (opts["size"].to_i**2)))
     x = rand(opts["size"].to_i)
     y = rand(opts["size"].to_i)
     r = rand(255)
     a = rand(255 * opts["opacity"].to_s.to_f)
     color = opts["monochrome"] ? ChunkyPNG::Color.rgba(r, r, r, a) : ChunkyPNG::Color.rgba(r, rand(255), rand(255), a)
     image.set_pixel(x, y, color)
  end
  
  data = Base64.encode64(image.to_blob).gsub("\n", "")
  Sass::Script::String.new("url('data:image/png;base64,#{data}')")
end