Allow a margin for eye 2d such that closely matching window sizes can be rendered

[Happypig375]

Toy Box and Racecourse work on Sand Box 2d. However, Fluid Sim is full of rendering errors. I don't think they are caused by my changes.

Also, I haven't tested changing display virtual resolution at runtime yet.

[bryanedds]

Yes, please ignore the current 2D rendering errors - it's a vulkan task item that's immediately prioritized.

[bryanedds]

Heads up:

Haven't had time to dig into this PR yet, but I've solved most of the rendering glitches in Fluid Sim, but not all.

Thanks for your patience as I work through my tasks, including reviewing this!

[bryanedds]

3D still renders exclusively inside the display virtual resolution, correct?

[bryanedds]

Seems to have multiple issues still. For example -

[Happypig375]

• 3D rendering will also extend the rendered viewport up to eye 2d viewed.
• The text positioning bug has been fixed.

[bryanedds]

I'm wondering if there's any actual utility in having a finite margin size or if the margin - when enabled, I guess - should just be whatever is over the current integer display scalar before reaching the next one.

[bryanedds]

Requesting that as much testing and QA work can be done on the submitter side for this rather precarious feature. There should be time to do so since we won't be able to merge this at least until after Vulkan Preview release.

[Happypig375]

The clipping and positioning of 2D entities on macOS broke after the changes of latest Vulkan, needs more experimentation

[Happypig375]

It's now fixed, but somehow resizing the window may trigger unwanted button clicks