module Magick::RVG::Stretchable

def align_to_viewport(width, height, sx, sy)
    tx = case @align
             when /\AxMin/
                 0
             when NilClass, /\AxMid/
                 (width - @vbx_width*sx) / 2.0
             when /\AxMax/
                 width - @vbx_width*sx
    end
    ty = case @align
             when /YMin\z/
                 0
             when NilClass, /YMid\z/
                 (height - @vbx_height*sy) / 2.0
             when /YMax\z/
                 height - @vbx_height*sy
    end
    [tx, ty]
end