Class: PSD::Renderer::Mask

Inherits:
Object
  • Object
show all
Defined in:
lib/psd/renderer/mask.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(canvas, mask_layer = nil) ⇒ Mask

Returns a new instance of Mask.



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# File 'lib/psd/renderer/mask.rb', line 6

def initialize(canvas, mask_layer = nil)
  @canvas = canvas
  @layer = canvas.node
  @mask_layer = mask_layer || @layer

  @mask_data = @mask_layer.image.mask_data
  @mask = @mask_layer.mask

  @mask_width = @mask.width.to_i
  @mask_height = @mask.height.to_i
  @mask_left = @mask.left.to_i + @mask_layer.left_offset
  @mask_top = @mask.top.to_i + @mask_layer.top_offset

  @doc_width = @layer.header.width.to_i
  @doc_height = @layer.header.height.to_i
end

Instance Attribute Details

#mask_data ⇒ Object

Returns the value of attribute mask_data.



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# File 'lib/psd/renderer/mask.rb', line 4

def mask_data
  @mask_data
end

Instance Method Details

#apply! ⇒ Object 



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# File 'lib/psd/renderer/mask.rb', line 23

def apply!
  PSD.logger.debug "Applying mask to #{@layer.name}"

  @canvas.height.times do |y|
    @canvas.width.times do |x|
      doc_x = @canvas.left + x
      doc_y = @canvas.top + y

      mask_x = doc_x - @mask_left
      mask_y = doc_y - @mask_top

      color = ChunkyPNG::Color.to_truecolor_alpha_bytes(@canvas.get_pixel(x, y))

      if doc_x < 0 || doc_x >= @doc_width || doc_y < 0 || doc_y >= @doc_height
        color[3] = 0
      elsif mask_x < 0 || mask_x >= @mask_width || mask_y < 0 || mask_y >= @mask_height
        color[3] = 0
      else
        color[3] = color[3] * @mask_data[@mask_width * mask_y + mask_x] / 255
      end

      @canvas.set_pixel x, y, ChunkyPNG::Color.rgba(*color)
    end
  end
end