transformPathWords

A copy of a flat path with mat applied to every point.

mocanvas has no PathBuilder: a shape's outline is a Geometry2d, and the *encoded* form every consumer of an outline shares is the engine's flat word stream (geometry.toPathWords()), which is what pathWordsToSvgD serializes and what the indicator layer strokes. So this is where a path transform belongs — one function, applied to the one encoding, rather than a second path abstraction that would have to be kept in step with the first.

``ts const flipped = transformPathWords(geometry.toPathWords(), Mat.Identity().translate(w, 0).scale(-1, 1)) const d = pathWordsToSvgD(flipped) ``

The input is never mutated. Control points transform with their anchors, so a curve stays a curve (an affine map takes a cubic bézier to a cubic bézier); a malformed stream is truncated at the bad word, exactly as pathWordsToSvgD truncates it.