rotate_scale.rb.html

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  <title>RMagick example: rotate_scale.rb</title>
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<h1>rotate_scale.rb</h1>
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<pre class="language-ruby">
# frozen_string_literal: true

require 'rvg/rvg'

rvg = Magick::RVG.new(400, 120) do |canvas|
  canvas.desc = 'Example - Rotate and scale transforms'
  canvas.background_fill = 'white'
  canvas.g.styles(fill: 'none', stroke: 'black', stroke_width: 3) do |grp|
    # Draw the axes of the original coordinate system
    grp.line(0, 1.5, 400, 1.5)
    grp.line(1.5, 0, 1.5, 120)
  end
  # Establish a new coordinate system whose origin is at (50,30)
  # in the original coord. system and which is rotated by 30 degrees.
  canvas.g.translate(50, 30) do |grp|
    grp.g.rotate(30) do |grp2|
      grp2.g.styles(fill: 'none', stroke: 'red', stroke_width: 3) do |grp3|
        grp3.line(0, 0, 50, 0)
        grp3.line(0, 0, 0, 50)
      end
      grp2.text(0, 0, 'ABC (rotate)').styles(font_size: 20, fill: 'blue', font_family: 'Verdana', font_weight: 'normal', font_style: 'normal')
    end
  end

  # Establish a new coordinate system whose origin is at (200,40)
  # in the original coord. systm and which is scaled by 1.5
  canvas.g.translate(200, 40) do |grp|
    grp.g.scale(1.5) do |grp2|
      grp2.g.styles(fill: 'none', stroke: 'red', stroke_width: 3) do |grp3|
        grp3.line(0, 0, 50, 0)
        grp3.line(0, 0, 0, 50)
      end
      grp2.text(0, 0, 'ABC (scale)').styles(font_size: 20, fill: 'blue', font_family: 'Verdana', font_weight: 'normal', font_style: 'normal')
    end
  end
end

rvg.draw.write('rotate_scale.gif')
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