The idea is to use the set of really small images from the lib folder
and run Cycles render on them comparing render output to reference
images in the tests repository.
For sure same thing could become more generic for BI or Freestyle
render engines.
Thanks Campbell for review and code tweaks!
Too many contrib addons are in an unstable state making the test not so useful.
Thanks to Sergey initial patch: D1012, redid mostly - but outcome is the same.
Those two mimic our BLI invert_m4_m4_safe - they add a small offset to diagonal values,
in case org matrix is degenerated, and if still non-invertible, return identity matrix.
Org patch by me, final enhanced version by ideasman42, many thanks!
Now always check for a default unit, and evaluate the whole expression in this "unit space".
Not an ideal solution, but should handle most cases nicely
(we can't address all possible corner cases anyway).
Note default unit is searched in current string first (bigger unit of current system wins),
then in previous string.
Note this also replaces ',' by '+' in default separation between units,
helps solving issues with parenthesis (e.g. (1'1")*2.5 would fail in existing code)!
This would break if someone uses py ops with lower precedence than '+' (like bitwise
operations, and comparison), but these are not expected usecase here anyway.
Reviewers: campbellbarton
Differential Revision: https://developer.blender.org/D340
