Draw directional arrows on lines and circles

[eric-wieser]

This is quite slow, so probably needs some more thought

It also seems to trigger a rendering bug (pixellation) in chrome:

[enkimute]

This is potentially a tiny bit more performant, as now marker defs are only created for each distinct color.

[eric-wieser]

I think the performance hit comes from switching from circle to path objects. Perhaps I should just create separate paths for the arrows, rather than trying to make use of the marker-mid stuff which isn't great for large circles / lines anyway

[hugohadfield]

awesome, hoping this makes it through to the conformal 3D visualiser, would in general make it a lot easier to keep track of the orientation of GA blades

[eric-wieser]

This is potentially a tiny bit more performant, as now marker defs are only created for each distinct color.

This also fixes a bug where in a changing document, the marker colors become stuck at the first color emitted.

[eric-wieser]

Think I worked around the rendering bug, but hard to say. Here's some more screenshots:

[kungfooman]

Thank you for this great work! I am just playing around with it, figured that tp = new Element() is initialized but never used.

Can this be integrated or is there some blocking issue? When performance is the only problem, why not make it an option? Slow/fast, for debugging.

[eric-wieser]

Unfortunately this probably needs to be rebuilt from scratch - the long and dense lines of ganja.js make git useless at trying to merge in the changes.

At any rate, I think @enkimute said they had their own variant of this in the works.