#!/usr/bin/ruby -w require 'RMagick' i = Magick::ImageList.new i.new_image(250, 250, Magick::HatchFill.new('light cyan')) gc = Magick::Draw.new # Move the origin to the center. gc.translate(124.5, 124.5) max_x = (i.columns-1)/2 max_y = (i.rows-1)/2 # Rotate 45 degrees gc.rotate(45) gc.stroke('red') # Draw down-pointing arrow gc.line(0, -max_y, 0, max_y) gc.line(0, max_y, 10, max_y-10) gc.line(0, max_y, -10, max_y-10) # Draw right-pointing arrow gc.line(-max_x, 0, max_x, 0) gc.line( max_x, 0, max_x-10, -10) gc.line( max_x, 0, max_x-10, 10) # Add labels gc.fill('black') gc.stroke('transparent') gc.text(8, 15, "'0,0'") gc.text(110, 16, "x") gc.text(12, 115, "y") gc.draw(i) #i.display i.write("rotate.gif")