#!/usr/bin/env ruby -w
require 'rmagick'

imgl = Magick::ImageList.new
imgl.new_image(390, 360, 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(20, 180, 20, 30, 320, 330, 320, 180)

# Draw circles around endpoints
gc.fill_opacity(0)
gc.stroke('gray50').stroke_width(1)
gc.circle(20, 180, 23, 183)
gc.circle(320, 180, 323, 183)

# Draw filled circles around control points
gc.line(20, 180, 20, 30)
gc.line(320, 180, 320, 330)
gc.fill_opacity(1)
gc.fill('gray50')
gc.circle(20, 30, 23, 33)
gc.circle(320, 330, 323, 333)

# Annotate
gc.font_weight(Magick::NormalWeight)
gc.font_style(Magick::NormalStyle)
gc.fill('black')
gc.stroke('transparent')
gc.text(29, 180, "'20,180'")
gc.text(29, 33,  "'20,30'")
gc.text(329, 330, "'320,330'")
gc.text(329, 180, "'320,180'")

gc.draw(imgl)
imgl.border!(1, 1, 'lightcyan2')

imgl.write('cbezier4.gif')
exit(0)