Some arcs
For my circle arc based project; related to Celtic knots etc.
click
on the red dots to move and change the arc.
before you do that, click on the "stop" button, and/or reset button, for clearer results.
Warning: animation effect 6 crashes my browser if I run it too long; not really sure why.
HTLM/JavaScript/Canvas; format for arc: ctx.arc(cx,cy,r, ang1, ang2)