module Cairo::Context::Blur - cairo-1.12.9 Documentation

# module Cairo::Context::Blur

### Public Instance Methods

pseudo_blur(radius=3, &block) click to toggle source

    # File lib/cairo/context/blur.rb, line 4
    def pseudo_blur(radius=3, &block)
      raise ArgumentError, "should specify block" if block.nil?
      pattern = push_group(Cairo::CONTENT_COLOR_ALPHA, false, &block)

      save do
        set_source(pattern)
        paint(0.5)
      end

      1.step(radius, 1) do |i|
        opacity = 0.075 - 0.005 * i
        next if opacity <= 0
        5.downto(1) do |ratio|
          r = i / ratio.to_f
          r_13 = r / 3.0
          r_23 = 2 * r_13
          [
           [-r, 0],
           [-r_23, r_23],
           [-r_23, r_13],
           [0, r],
           [r_13, r_23],
           [r_23, r_23],
           [r, 0],
           [r_23, -r_13],
           [r_23, -r_23],
           [0, -r],
           [-r_13, -r_23],
           [-r_23, -r_23],
          ].each do |x, y|
            save do
              translate(x, y)
              set_source(pattern)
              paint(opacity)
            end
          end
        end
      end
    end