Selection system enhancements / overhaul

[tetektoza]

Proposal description

There are a lot of issues regarding current selection system. Well, not in terms of performance but in terms how it looks. This grant is supposed to resolve those problems, enhance the selection system visually and do a few things around it specified in below issues. Note that those are not performance improvements or quality of code improvements.

• UI: Selected/hovered faces in the 3D view appear tinted with face color - Chosen selection color is not the one which is visible. FreeCAD#10614
• UX: Hidden selection is invisible FreeCAD#13981
• UI/UX: Selecting a vertex with a more visible indicator, such as a ball FreeCAD#14445
• UI: Selection highlight intensity makes selection undiscerable and needs Opacity setting FreeCAD#23529
• Improve pre-selection visibility FreeCAD#13975
• Core: "Go to selection" not working FreeCAD#14021

As the selection system is a bit of a mess for now, I consider this as a challenging piece of work. I may add another grant to refactor the main files that are related to selection.

There is small demo what I had before, of course this demo wasn't supposed to land on this FPA grant proposal, so notice the colors are not beautiful, but I was sharing that on the DWG channel to discuss if it's going in a good direction back then. Also, of course, this demo is nowhere finished work in this area but rather a start around it.

testing_hidden_edges.mp4

Deliverables

As specified above, I plan to do above tickets + focus on conversations with DWG to make it as beautiful as possible.

Timeline

I'm planning to start this quarter and finish till the end of it. Previously I was able to get some good progress in this direction in a matter of few weeks, but found some obstacles.

Risks and mitigation

I don't see any risks for now, I plan to start as soon as this grant will be accepted, and finish ASAP as well.

Compensation

3000 euros for all of the tickets. If something won't be delivered, we can divide 3000 by the amount of tickets and just decide what has been actually delivered.

About you

Been contributing past few months, I think I've delivered few small things that are interesting so hopefully this one will be too.
https://github.com/FreeCAD/FreeCAD/pulls/tetektoza

Regarding the experience around those areas of code - I've touched it already in Clarify Selection tool as I was trying to port it, so I understand the overall architecture.

[Reqrefusion]

The Selection system is definitely not the most liked and the improvements here look good to me. I remember that it was said that the relevant codes were very complex when we were talking about this for a while, but I'm not sure. Also, you have already proven that you are working with the @FreeCAD/design-working-group, but maybe they have something to say.

[pierreporte]

We did discuss together with @tetektoza about this implementation and it seems to me there was a consensus it was a very good improvement. I personally fully support the proposal.