It is up to the calling application to convert lengths in non-pixel units
(i.e. those where the @unit field is not RSVG_UNIT_PX) into something
meaningful to the application. For example, if your application knows the
dots-per-inch (DPI) it is using, it can convert lengths with @unit in
RSVG_UNIT_IN or other physical units.
rsvg.types.Length values are used in rsvg.handle.Handle.getIntrinsicDimensions, for example, to return the CSS length values of the width and height attributes of an <svg> element.
This is equivalent to CSS lengths.
It is up to the calling application to convert lengths in non-pixel units (i.e. those where the @unit field is not RSVG_UNIT_PX) into something meaningful to the application. For example, if your application knows the dots-per-inch (DPI) it is using, it can convert lengths with @unit in RSVG_UNIT_IN or other physical units.