#!/usr/bin/ruby -w require 'RMagick' canvas = Magick::Image.new(260, 125) gc = Magick::Draw.new gc.fill('black') gc.rectangle(10,20, 250,90) gc.stroke('blue') gc.fill('yellow') gc.stroke_width(10) gc.opacity('25%') gc.roundrectangle(20,20, 60,90, 5,5) gc.opacity('50%') gc.roundrectangle(80,20, 120,90, 5,5) gc.opacity(0.75) gc.roundrectangle(140,20, 180,90, 5,5) gc.opacity(1) gc.roundrectangle(200,20, 240,90, 5,5) gc.font_weight(Magick::NormalWeight) gc.font_style(Magick::NormalStyle) gc.stroke('transparent') gc.fill('black') gc.gravity(Magick::SouthGravity) gc.text(-90,15, '"25%"') gc.text(-30,15, '"50%"') gc.text( 30,15, '"75%"') gc.text( 90,15, '"100%"') gc.draw(canvas) canvas.write("opacity.png") exit