Class: RComposite::Layer

Inherits:
Object
  • Object
show all
Defined in:
lib/rcomposite/layer.rb

Direct Known Subclasses

AdjustmentLayer, FillLayer, LayerMask

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Layer

Returns a new instance of Layer.



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# File 'lib/rcomposite/layer.rb', line 34

def initialize(options = {})
  if options[:file]
    @image = Magick::Image.read(options[:file]).first
    @image.background_color = 'transparent'
  elsif options[:blob]
    @image = Magick::Image.from_blob(options[:blob]).first
    @image.background_color = 'transparent'
  elsif options[:image]
    if options[:image].is_a? Magick::Image
      @image = options[:image]
    end
  end

  if @image
    @image.matte = true
    @mode = Normal
    @offset_x = 0
    @offset_y = 0
    @opacity_percent = 100
    @layer_mask = nil
  else
    raise "Layer not created -- no layer source."
  end
end

Instance Attribute Details

#image ⇒ Object

Returns the value of attribute image.



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# File 'lib/rcomposite/layer.rb', line 31

def image
  @image
end

#offset_x ⇒ Object (readonly)

Returns the value of attribute offset_x.



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# File 'lib/rcomposite/layer.rb', line 32

def offset_x
  @offset_x
end

#offset_y ⇒ Object (readonly)

Returns the value of attribute offset_y.



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# File 'lib/rcomposite/layer.rb', line 32

def offset_y
  @offset_y
end

Instance Method Details

#height ⇒ Object 



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# File 'lib/rcomposite/layer.rb', line 74

def height
  @image.rows
end

#join_set(set) ⇒ Object 



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# File 'lib/rcomposite/layer.rb', line 109

def join_set(set)
  set.add_layer(self)
end

#layer_mask(options, &block) ⇒ Object 



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# File 'lib/rcomposite/layer.rb', line 59

def layer_mask(options, &block)
  @layer_mask = LayerMask.new options
  
  @layer_mask.instance_eval &block if block_given?
end

#leave_set(set) ⇒ Object 



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# File 'lib/rcomposite/layer.rb', line 113

def leave_set(set)
  set.remove_layer(self)
end

#merge_down(image) ⇒ Object 



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# File 'lib/rcomposite/layer.rb', line 65

def merge_down(image)
  @layer_mask.apply self if @layer_mask
  image.composite!(@image, @offset_x, @offset_y, @mode)
end

#mode(mode = nil) ⇒ Object 



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# File 'lib/rcomposite/layer.rb', line 100

def mode(mode = nil)
  return @mode if mode.nil?
  @mode = mode
end

#offset(x, y) ⇒ Object 



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# File 'lib/rcomposite/layer.rb', line 78

def offset(x, y)
  @offset_x = x
  @offset_y = y
end

#opacity(percent) ⇒ Object 



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# File 'lib/rcomposite/layer.rb', line 87

def opacity(percent)
  @opacity_percent = percent
  # intercept original alpha channel with pixel intensity
  alpha_channel = @image.channel(Magick::AlphaChannel).negate
  intensity = (Magick::MaxRGB * (percent/100.0)).round
  alpha_channel.composite!(Magick::Image.new(width, height) { self.background_color = Magick::Pixel.new(intensity,intensity,intensity) }, Magick::CenterGravity, Multiply)
  alpha_channel.matte = false
  
  @image.composite!(alpha_channel, Magick::CenterGravity, Magick::CopyOpacityCompositeOp)
  return true
end

#rotate(degrees) ⇒ Object 



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# File 'lib/rcomposite/layer.rb', line 83

def rotate(degrees)
  @image.rotate!(degrees)
end

#save_as(filename) ⇒ Object 



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# File 'lib/rcomposite/layer.rb', line 105

def save_as(filename)
  @image.write(filename)
end

#width ⇒ Object 



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# File 'lib/rcomposite/layer.rb', line 70

def width
  @image.columns
end