Changes the basic line drawing elements (rect, circle, ellipse, polyline and polygon) to path elements. The transformations are as follows:

rect
Simple rects get transformed to a path: M..h..v..h..z
If rx or ry attributes are defined, path is M..a..h..a..v..a..h..a..z
circle
Gets converted to path of form M..a..a..a..a..z
ellipse
Gets converted to path of form M..a..a..a..a..z
line
Gets converted to path of form M..L
polyline
Gets converted to path of form M....
polygon
Gets converted to path of form M...Z

For polyline and polygon, the coordinates after the first two will be equivalent to L commands as SVG defines. Thus it is the same as M..L..L.. etc

The resulting path can be transformed by remove_arc to change the arcs to cubics.