Class: Fleximage::Operator::Shadow

Inherits:
Base
  • Object
show all
Defined in:
lib/fleximage/operator/shadow.rb

Overview

Add a drop shadow to the image.

image.shadow(options = {})

Use the following keys in the options hash:

  • offset: distance of the dropsahdow form the image, in FlexImage size format. Positive number move it down and right, negative numbers move it up and left.

  • blur: how blurry the shadow is. Roughly corresponds to distance in pixels of the blur.

  • background: a color for the background of the image. What the shadow fades into.

    Use an RMagick named color or use the color method in FlexImage::Controller, or a Magick::Pixel object.

  • color: color of the shadow itself. Use an RMagick named color or use the color method in FlexImage::Controller, or a Magick::Pixel object.

  • opacity: opacity of the shadow. A value between 0.0 and 1.0, where 1 is opaque and 0 is transparent.

Example:

@photo.operate do |image|
  # Default settings
  image.shadow(
    :color      => 'black',    # or color(0, 0, 0)
    :background => 'white',    # or color(255, 255, 255)
    :blur       => 8,
    :offset     => '2x2',
    :opacity    => 0.75 
  )

  # Huge, red shadow
  image.shadow(
    :color      => color(255, 0, 0),
    :background => 'black',    # or color(255, 255, 255)
    :blur       => 30,
    :offset     => '20x10',
    :opacity    => 1
  )
end

Instance Method Summary collapse

Methods inherited from Base

#color, color, #execute, #initialize, #scale, #scale_and_crop, size_to_xy, #size_to_xy, #stretch, #symbol_to_blending_mode, #symbol_to_gravity

Constructor Details

This class inherits a constructor from Fleximage::Operator::Base

Instance Method Details

#operate(options = {}) ⇒ Object 



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# File 'lib/fleximage/operator/shadow.rb', line 48

def operate(options = {})
  options = options.symbolize_keys if options.respond_to?(:symbolize_keys)
  defaults = {
    :offset     => 2,
    :blur       => 8,
    :background => 'white',
    :color      => 'black',
    :opacity    => 0.75
  }
  options = options.is_a?(Hash) ? defaults.update(options) : defaults

  # verify options
  options[:offset] = size_to_xy(options[:offset])
  options[:blur]   = options[:blur].to_i

  options[:background]    = Magick::Pixel.from_color(options[:background]) unless options[:background].is_a?(Magick::Pixel)
  options[:color]         = Magick::Pixel.from_color(options[:color])      unless options[:color].is_a?(Magick::Pixel)
  options[:color].opacity = (1 - options[:opacity]) * 255

  # generate shadow image
  shadow = @image.dup
  shadow.background_color = options[:color]
  shadow.erase!
  shadow.border!(options[:offset].max + options[:blur] * 3, options[:offset].max + options[:blur] * 3, options[:background])
  shadow = shadow.blur_image(0, options[:blur] / 2)

  # apply shadow
  @image = shadow.composite(
    @image, 
    symbol_to_gravity(:top_left), 
    (shadow.columns - @image.columns) / 2 - options[:offset][0], 
    (shadow.rows    - @image.rows)    / 2 - options[:offset][1], 
    symbol_to_blending_mode(:over)
  )
  @image.trim!
end