NPCs' wounded start time is saved incorrectly

[Decane]

NPCs are meant to self-heal 60 real seconds after becoming heavily wounded - a state that manifests as them falling to the ground in a fetal position and vying for a medkit.

So, if an NPC is heavily wounded 5 minutes after the game is launched and a save is created 20 seconds later in the same session, you might expect that, upon loading the save, there would still be 40 seconds remaining of the NPC's heavily wounded state before the NPC self-heals and gets up.

However, the wounded start time saved by xr_wounded.script for savegame persistence is time_global(), which returns the number of milliseconds since the game was launched. The time against which it compares this to determine if 60 seconds have elapsed is the contemporary time_global().

So, to continue the example above: suppose that after saving, you exit the game to the desktop and launch it again, thus resetting time_global(). Suppose you load the save with the wounded NPC 10 minutes after launching the game, perhaps because you first went to make tea or something.

The NPC would self-heal immediately upon the save being loaded. Why? Because the contemporary time_global() after loading would be 10 * 60 * 1000 (10 minutes), which exceeds the saved time_global() of 5 * 60 * 1000 + 20 * 1000 (5 minutes 20 seconds) by more than 60 * 1000 (60 seconds). Conversely, if the save were loaded 1 minute since the game was launched, the heavily wounded NPC would remain in a heavily wounded state for much longer than intended - 4 minutes and 20 seconds.

See the SRP version of release_body_manager.script for a good solution to this.