## Link to GitHub Issue or related Pull Request, if one exists
Fixes#737, regressed by #707
## Description of change
ImGui backend for DX11 pulled in dependency on a specific version of
`d3dcompiler_47.dll` which is not present on stock Win7 OS image.
Change this to a runtime load of the DLL and disable the overlay if we
can't find one.
## Testing
- [x] Win11, DX11 overlay
- [x] Win11, DX9 overlay
- [x] Win7, DX9 overlay
## Link to GitHub Issue or related Pull Request, if one exists
Fixes#134
## Description of change
Add ImGui DX11 backend implementation, and integrate into the spice
overlay.
The tricky part is that some of the Unity games:
1. Launch multiple windows, and
2. Can be resized (even full screen games launch at a certain resolution
and then expand to fit desktop resolution)
3. lazy load DX11 DLLs
This PR also adds screenshot functionality, but screen resize is not
implemented.
## Testing
Seems to be working for most games. Need to do final tests for:
- [x] CCJ (attract movie plays as well)
- [x] Busou Shinki (title movie plays)
- [x] MFG
- [x] QuizKnock
- [x] Polaris Chord
- [x] check dx9 for regression
## 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