Paintable canvas not translating negative values

[PGriffith]

Painting is complicated, for better or for worse. Are you sure about your coordinate system, scaling applied after, etc?
https://www.oracle.com/java/technologies/painting.html#callbacks

@markusx1094

Also the calculations like angleCalc only need to be called when I change the template instance size so is there a way to store the values somehow so it only goes through the calculation the first time the client/page is opened and not when the color changes? Do custom methods already do this?

If you want to 'cache' an ephemeral value, you can use get or putClientProperty to store/retrieve arbitrary objects. They'll be stored directly on your component instance (the paintable canvas in this case); since you're sensitive to your component's size, you might want to use the component dimensions as the cache key.