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

    i = Magick::ImageList.new
    i.new_image(500, 350, Magick::HatchFill.new('seashell'))
    gc = Magick::Draw.new

    # Draw Bezier curve
    gc.stroke('red')
    gc.stroke_width(2)
    gc.fill_opacity(0)
    gc.bezier(100,200, 100,100, 400, 100, 400,200)

    # Draw circles around endpoints
    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, 100,100)
    gc.line(400,200, 400,100)
    gc.fill_opacity(1)
    gc.fill('gray50')
    gc.circle(100,100, 103,103)
    gc.circle(400,100, 403,103)

    # Annotate
    gc.fill('black')
    gc.stroke('transparent')
    gc.text(107,200, "'100,200'")
    gc.text(107,100, "'100,100'")
    gc.text(407,200, "'400,200'")
    gc.text(407,100, "'400,100'")
    gc.draw(i)
    i.write('cbezier1.gif')
    exit(0)