## Link to GitHub Issue or related Pull Request, if one exists
n/a
## Description of change
Create three distinct layers for the overlay:
1. Bottommost persistent layer - non-interactable layer that is always
on. This was only for notifications, but now the FPS widget lives here
as well.
2. Overlay windows layer - most interactable windows go here.
3. Topmost main menu - this is reserved for the main menu (escape key)
and this is a modal dialog that occludes the layers below.
Why?
- `toggle overlay` behavior with FPS widget *also* toggling on/off was a
bit confusing (now they're two separate keys)
- FPS widget is popular, but it caused the entire overlay to be active,
which affects how input is handled
- the main menu being a standalone window was a little awkward (now it's
a modal)
## Testing
## Link to GitHub Issue, if one exists
n/a
## Description of change
Change the dark brown colors used in widget backgrounds to dark gray.
Decrease the in-game overlay transparency (more opaque): 80% -> 96%.
## Testing
Tested cfg and in-game overlay.
## Link to GitHub Issue, if one exists
n/a
## Description of change
Functionally, no change.
Move ImGui library files around so that they mirror how they are
structured in imgui releases. This will make it easier to migrate to a
future version of ImGui.
Add a handful of static asserts to check that we have the necessary
features enabled / disabled in imgui header.
## Compiling
👍
## Testing
Tested 32-bit overlay, 64-bit overlay, TDJ, and UFC overlays, and
spicecfg.
Interesting finds during ImGui testing (not part of this PR, but for
future reference when upgrading imgui version):
* Updating dx9 backend to the newest causes TDJ to stop rendering the
overlay completely (fine in UFC or any other game)
* Omitting `IMGUI_USE_BGRA_PACKED_COLOR` causes spicecfg software
renderer to use the wrong color (RGB format parsing error probably)
* At some point - v1.90? the `About` and `Licenses` buttons in spicecfg
stop responding after an upgrade, maybe our improper usage of MenuItem?
* Using the docking branch of ImGui is not required but we should just
stick to it for multi-viewport functionality which we may want to use
later.
bicarus