wumpus-core

Copperbox revision 1791.

Initial work on changing the transformations on Primitives.

Previously primitives had rather "special" interpretations of transformation - rotations on ellipses or text labels were about their respective origins (center for ellipse, baseline-left for text). There was reasoning behind this Primitives weren't considered to be in an Affine space and it was important to have angled text - say if you want to create a graph where the baseline are all angled at 45deg you would want to rotate all labels individually about their center. However, now that I've written more code this has begun to seem naive, a better strategy is to have constructors for angled versions of ellipses and text labels and make rotation follow the standard affine interpretation.

In this revision, I've put in the new constructors for angled labels and ellipses and have changed the rotation behaviour of primitives, these changes are easy - most of the work is going to be creating examples to show that the new behaviour works as intended.