Logic has been put in place to detect when new lines need to be rendered
... in the middle of something ...
Rendering now only happens when necessary. Not smooth.

The plan is to now transition into using scale transforms
instead of re-calculating the d0 each time. This should
provide significant speed improvements
This is what a lock-scale button would look like. Good idea.
Using transform scale instead of re-drawing!

Normal zooming works perfectly. It's fast on firefox!
Will have to re-do the scale on each level change
so that it doesn't keep scaling in the x axis and get ugly.
Some refactoring.
Now it looks beautiful! Rendering at different scales!
Looking how it should, but without the intermediate scaling.
Did it! Lines now render static, and scale to the right size.
Everything transitions properly now. :)