path data attribute lacks units!

Hi there, I'm working with a group of people in the open source world, trying to use SVG as an interchange format for 2-dimensional CAD (computer-aided design) data. We are hoping to replace the old closed-source DXF format with SVG, and we're mostly having good success.

However, we have run in to one stumbling block.  Some shapes can be well represented by SVG Basic Shapes, and those work well.  Some shapes cannot be represented by Basic Shapes and instead require Paths, for example partial arcs.

The problem is that Path data does not have user-specifiable units.  It is always represented in "px" user units, which have undefined size.  We're currently assuming that the SVG will be viewed/used in a 90 dpi environment, and that is getting us past this obstacle, but it seems an unsafe assumption to make.  We'd much rather have proper units on path data, and remove this ambiguity.

Is this limitation intentional?

Is there a way to specify path data units that we're missing?


Thanks for your work on a (mostly!) great spec!  :-)


-- 
Sebastian Kuzminsky

Received on Wednesday, 8 February 2012 22:11:11 UTC