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

    i = Magick::ImageList.new
    i.new_image(550, 350, Magick::HatchFill.new('seashell'))
    gc = Magick::Draw.new

    # Draw Bezier curve
    gc.stroke('red')
    gc.stroke_width(3)
    gc.fill_opacity(0)
    gc.bezier(100,200, 175,100, 475,100, 400,200)

    # Draw circles around end points
    gc.fill_opacity(0)
    gc.stroke('gray50').stroke_width(1)
    gc.circle(100,200, 103, 203)
    gc.circle(400,200, 403, 203)

    # Draw filled circles around control points
    gc.line(100,200, 175,100)
    gc.line(400,200, 475,100)
    gc.fill_opacity(1)
    gc.fill('gray50')
    gc.circle(175,100, 178,103)
    gc.circle(475,100, 478,103)

    # Annotate
    gc.fill('black')
    gc.stroke('transparent')
    gc.text(109,200, "'100,200'")
    gc.text(182,100, "'175,100'")
    gc.text(409,200, "'400,200'")
    gc.text(480,100, "'475,100'")

    gc.draw(i)
    i.write('cbezier2.gif')
    exit(0)