I am working on a diagramming tool that has the combination of a syntax for diagramming as code, extended with a syntax to define rendering constraints (e. g. this part of the diagram shoukd be left of this part, or this arrow must not cross this arrow). I hope this will greatly ease consistent diagram rendering and also getting the final mile pixel perfect.

Currently already have a very alpha version working of the renderer using Cassowary, and working on making a good GUI.