* Decrease close enough tolerances
* Add a draggable for offsetting the puppet in world space
* Draw editor in the same batch, overlapping the puppet
* Only select shapes when the mouse is first clicked
* Ignore invisible shapes in selection
* Remove dead SVG-based bone code
* Move atlas rectangle drawing into editor section
* Update STB for C compatibility
* Bind F1 to open the code that defined the hovered UI widget
* Use the C API for Handmade math constructs
* Handle UI inquiries by sending them straight to Emacs for now
The problem was that I was not taking into account the offset between
the parent's end position and the child's start position. This offset
needed to be rotated the same as the parent in order to maintain the
relationship.
There are still problems with the end bone not reaching the effector
when it ought to be able to.
I didn't get it quite right. There are still some kinks. The main
issue I had was assuming that the repeated rotation of child bones by
the parent's rotation was okay. I think that accumulated a lot of
error quickly.
The following blog post helped me:
https://www.ryanjuckett.com/cyclic-coordinate-descent-in-2d/
