selection highlighting nearly invisible for non-terminal stick atoms

[Elaine Meng]

ChimeraX selection highlighting of non-endcap atoms in stick style is nearly impossible to see. It is a slight twinkle when the structure is rotated. See images attached for ChimeraX selection highlighting compared to that in Chimera.

TomG said: I don't have an idea for fixing it. Could make the non-terminal atoms a little bigger but that is probably ugly. Could possibly do some weird hack where the outline is computed by drawing the selected atoms a bit closer to the camera so they poke through. Would have to try that to see what it looks like.

[Tom Goddard]

I made the selection outlines around stick atoms that are mostly hidden by attached stick bonds more visible. Often it shows a full circular outline of the buried outline now, although it depends on how zoomed in the atom is. Let's see if this is overall better.

Another issue is that on retina displays the selection outline is very thin, making it hard to see. I might look at using outline width 2 instead of 1 on retina displays. The current code would render that much slower, so I'll need to look at whether I can render width 2 fast.

[Tom Goddard]

I made the selection outline 2 pixels wide on retina displays and 1 pixel wide on non-retina. Also I added set command selectionColor and selectionWidth options.