# NewCoordSys.rb

    require 'rvg/rvg'

    rvg = Magick::RVG.new(400, 150) do |canvas|
        canvas.background_fill = 'white'
        canvas.desc = 'Example NewCoordSys - New user coordinate system'
        canvas.g.styles(:fill=>'none', :stroke=>'black', :stroke_width=>3) do |grp|
            # Draw the axes of the original coordinate system
            grp.line(0, 1.5, 400, 1.5)
            grp.line(1.5, 0, 1.5, 150)
        end

        canvas.g do |grp|
            grp.text(30, 30, 'ABC (orig coord system)').styles(:font_size=>20, :font_family=>'Verdana')
        end

        # Establish a new coordinate system, which is
        # shifted (i.e., translated) from the initial coordinate
        # system by 50 user units along each axis.
        canvas.g.translate(50, 50) do |grp|
            grp.g.styles(:fill=>'none', :stroke=>'red', :stroke_width=>3) do |grp2|
                # Draw lines of length 50 user units along
                # the axes of the new coordinate system
                grp2.line(0, 0, 50, 0)
                grp2.line(0, 0, 0, 50)
            end
            grp.text(30, 30, 'ABC (translated coord system)').styles(:font_size=>20, :font_family=>'Verdana')
        end

    end

    rvg.draw.write('NewCoordSys.gif')

Close window