# cbezier2.rb

    #!/usr/local/bin/ruby18 -w
    require 'RMagick'

    imgl = Magick::ImageList.new
    imgl.new_image(470, 150, Magick::HatchFill.new('white','lightcyan2'))
    gc = Magick::Draw.new

    # Draw Bezier curve
    gc.stroke('red')
    gc.stroke_width(3)
    gc.fill_opacity(0)
    gc.bezier(25,125, 100,25, 400,25, 325,125)

    # Draw circles around end points
    gc.fill_opacity(0)
    gc.stroke('gray50').stroke_width(1)
    gc.circle(25,125, 28, 128)
    gc.circle(325,125, 328, 123)

    # Draw filled circles around control points
    gc.line(25,125, 100,25)
    gc.line(325,125, 400,25)
    gc.fill_opacity(1)
    gc.fill('gray50')
    gc.circle(100,25, 103,28)
    gc.circle(400,25, 403,28)

    # Annotate
    gc.fill('black')
    gc.stroke('transparent')
    gc.text(34,125, "'25,125'")
    gc.text(107,25, "'100,25'")
    gc.text(335,125, "'325,125'")
    gc.text(405,25, "'400,25'")

    gc.draw(imgl)
    imgl.border!(1,1, "lightcyan2")
    imgl.write('cbezier2.gif')
    exit(0)

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