calc_label_rot_and_inline(self, slc, ind, lw, lc=None, spacing=5)
If lc is not None or empty, also break contours and compute inlining.
spacing is the empty space to leave around the label, in pixels.
Both tasks are done together to avoid calculating path lengths multiple times, which is relatively costly.
The method used here involves computing the path length along the contour in pixel coordinates and then looking approximately (label width / 2) away from central point to determine rotation and then to break contour if desired.
Calculate the appropriate label rotation given the linecontour coordinates in screen units, the index of the label location and the label width.
Hover to see nodes names; edges to Self not shown, Caped at 50 nodes.
Using a canvas is more power efficient and can get hundred of nodes ; but does not allow hyperlinks; , arrows or text (beyond on hover)
SVG is more flexible but power hungry; and does not scale well to 50 + nodes.
All aboves nodes referred to, (or are referred from) current nodes; Edges from Self to other have been omitted (or all nodes would be connected to the central node "self" which is not useful). Nodes are colored by the library they belong to, and scaled with the number of references pointing them