Swarm.Game.Scenario.Topography.Structure.Recognition.Symmetry

Symmetry analysis for structure recognizer.

Documentation

checkSymmetry :: (MonadFail m, Eq a) => NamedGrid a -> m (SymmetryAnnotatedGrid (NamedGrid a))

Warns if any recognition orientations are redundant by rotational symmetry. We can accomplish this by testing only two rotations:

1. Rotate 90 degrees. If identical to the original orientation, then has 4-fold symmetry and we don't need to check any other orientations. Warn if more than one recognition orientation was supplied.
2. Rotate 180 degrees. At best, we may now have 2-fold symmetry. Warn if two opposite orientations were supplied.