[Bug] Automap shuffles things on loadgame.

[Catoptromancy]

Latest git: commit f3f3cb0
Built on Debian 11, 5.10.0-16-amd64 #1 SMP Debian 5.10.127-1 (2022-06-30) x86_64 GNU/Linux

http://www.geocities.ws/catodemos/doom/ports/crispyDOOM0019a.png

The items on the automap can get randomly shuffled around each time the savegame is loaded, while game is kept open. Sometimes every item shows on the same coordinate, sometimes just one or two items are noticeably moved.
This seems to happen more often on larger maps with lots of items, near the exit....or maybe it is just more noticable.
Can be triggered on smaller maps, but seems to take make more loaded games, and fewer items move.

Just save a game, IDDT for things in automap, then reload savegame multiple times and keep checking voids in automap. Voids are easy to spot things in.

Wad:
https://static.angryscience.net/pub/hosted/tnt2/TNT2_beta2.zip

Savegame: Large map, lots of items, at almost 100%.
http://www.geocities.ws/catodemos/doom/ports/tnt2_beta2_doomsav5.dsg

$ crispy-doom -iwad tnt.wad -merge tnt2_beta2.wad -deh TNT2_beta2.DEH

That savegame and pwad can trigger lots of items to move in a dozen reloads. Using plutonia.wad on map23 with game saved at player start, can take a dozen reloads just to see any movement.

[JNechaevsky]

Yeah, I can reproduce it, but on my side there is a firework effect on automap. 😳

It does not seems to be related to automap interpolation code. Commenting out this block seems to be fixes drawing:
https://github.com/fabiangreffrath/crispy-doom/blob/master/src/doom/p_mobj.c#L561-L565

Edit: ...or strict this block to (mobj->interp < 0 && !automapactive)? Can't re-check for now until evening.

[fabiangreffrath]

Hm, I'm a bit surprised we don't set oldx etc in saveg_read_mobj_t(). Maybe this could help.

crispy-doom/src/doom/p_saveg.c

Line 310 in f3f3cb0

str->x = saveg_read32();

[rfomin]

Hm, I'm a bit surprised we don't set oldx etc in saveg_read_mobj_t(). Maybe this could help.

I can confirm, this patch fixes http://www.geocities.ws/catodemos/doom/ports/tnt2_beta2_doomsav5.dsg save for me:

diff --git a/src/doom/p_saveg.c b/src/doom/p_saveg.c
index 3884b44d..4e263513 100644
--- a/src/doom/p_saveg.c
+++ b/src/doom/p_saveg.c
@@ -418,6 +418,12 @@ static void saveg_read_mobj_t(mobj_t *str)

     // struct mobj_s* tracer;
     str->tracer = saveg_readp();
+
+    str->interp = 0;
+    str->oldx = 0;
+    str->oldy = 0;
+    str->oldz = 0;
+    str->oldangle = 0;
 }

 // [crispy] enumerate all thinker pointers

[fabiangreffrath]

Could you please file a PR for this? That'd be easier for me to handle from my phone office in Croatia. 😁

Is Woof also affected?

[rfomin]

Could you please file a PR for this?

Done.

Is Woof also affected?

No, we load or reset these fields in Woof, depending on the savegame version.

[mikeday0]

Could you please file a PR for this? That'd be easier for me to handle from my phone office in Croatia. 😁

Is Woof also affected?

Safe travels! I have always heard Croatia is a beautiful place.

[fabiangreffrath]

Safe travels! I have always heard Croatia is a beautiful place.

Thank you! It is beautiful, though it's incredibly hot today. But the Adriatic Sea compensates for an 18 hour car drive.

[JNechaevsky]

He-ey, have a good and calm vacation! ☕☀️🌊