Just Cause 4 Investigation (Patreon)

https://www.protondb.com/app/517630

https://github.com/ValveSoftware/Proton/issues/2596

Bug Reference

https://bugs.winehq.org/show_bug.cgi?id=46534

When running Just Cause 4 under Steam, there doesn't appear to be any issues what so ever, ok maybe

some graphics glitches from time to time but the game seem to run without a hitch.  Epic on the other hand crashed and

burned on startup.

It sometimes surprises me how the same game from different providers, Steam vs Epic, uses completely different API to do the same thing.

The fundamental difference was the INetworkInformationStatics interface used the Epic version, to check for an internet connection and setup a callback if one wasn't available.  If it happen to setup the callback, you never get a chance to login.

As it turned out, the wine bug report had a possible set of patches to fix the issue, which was half right.  At least it was in the right direction, and something to build on.

One of the main problems trying to add the missing interfaces was wine lack of support for all of UMP features, wine's widl just isn't up to the task.  As my main goal was to get Just Cause 4 working under Epic, I took at few shortcuts to make it work.

Overall the patches implement as much as required to let Just Cause 4, check for an internet connection and allow you to play.

This patchset, might stay a while in staging, as widl needs to be patched before these could possibly be sent upstream but rest assured that in time they will be.

For people who have this on Epic and want to give it a whirl, there was a delay on first startup connecting, so a little patience is required.

Remember to report bugs at https://bugs.winehq.org, so issues aren't lost in the ether.

Final note: use dxvk when running this, as builtin has poor frame rates.