#RsvgLength values are used in rsvg_handle_get_intrinsic_dimensions(), for
example, to return the CSS length values of the <literal>width</literal> and
<literal>height</literal> attributes of an <literal><svg></literal>
element.
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.
#RsvgLength values are used in rsvg_handle_get_intrinsic_dimensions(), for example, to return the CSS length values of the <literal>width</literal> and <literal>height</literal> attributes of an <literal><svg></literal> element.
This is equivalent to <ulink url="https://www.w3.org/TR/CSS21/syndata.html#length-units">CSS lengths</ulink>.
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.