#!/usr/bin/ruby -w require 'RMagick' i = Magick::ImageList.new i.new_image(400, 400) { self.background_color = "white" } gc = Magick::Draw.new gc.font('Helvetica').pointsize(128) # Draw large black percentages gc.text( 10,140,"'100'") gc.text(235,140,"'80'") gc.text( 35,340,"'60'") gc.text(235,340,"'40'") # Establish the stroke and fill parameters gc.stroke("'blue'").stroke_width(10).stroke_linejoin('round') gc.fill('yellow') # For each of the 4 opacity levels, draw a blue-rimmed # yellow triangle over the corresponding number. # Note that the opacity argument can be either a number # between 0 and 1 gc.opacity('100%') or 1.00 gc.polygon(25,175, 175, 25, 25,25) gc.opacity('80%') or 0.80 gc.polygon(225,175, 375,25, 225,25) gc.opacity(0.60) or '60%' gc.polygon( 25,375, 175, 225, 25,225) gc.opacity(0.40) or '40%' gc.polygon(225,375, 375,225, 225,225) gc.draw(i) #i.display i.write("opacity.gif")