Is there a tool that estimates the possibility of savegame buffer overflows?

[printz]

Is there any tool that, by looking at the level in the wad, can determine if saving will cause a "savegame buffer overrun" error in vanilla Doom/Heretic/Hexen/Strife? I'm especially interested if it doesn't support just Doom. It would be more convenient than having to save at key moments during the game repeatedly just to see if it happens.

[scifista42]

Any map with at least one Revenant has the possibility of savegame buffer overflow, the player just has to let him spawn a sufficient number of homing missiles, and keep running around to keep them flying.

[Graf Zahl]

Since all active projectiles will affect the savegame's size a safe estimation is not really doable.

Of course you can write a tool that can calculate the required buffer size at any time, what it needs to do is count all thinkers on the map, add up their size and constantly print a number on the screen.

[scifista42]

Graf Zahl said:

Since all active projectiles will affect the savegame's size a safe estimation is not really doable.

It is doable in theory, for example a map with a single small room and a single Imp can safely be estimated not to overflow. The tool would have to estimate a maximum possible number of flying projectiles not only by monster count, but also by measuring available space that flying projectiles can possibly occupy, and accounting for speed of each projectile type and fire rate of each monster type.

[Linguica]

I think the best bet would be to petition the Chocorenderlimits guy to add a realtime "savegame buffer size" counter and then just play around in the level.

[printz]

scifista42 said:

Any map with at least one Revenant has the possibility of savegame buffer overflow, the player just has to let him spawn a sufficient number of homing missiles, and keep running around to keep them flying.

That's obviously theoretical and highly difficult to do in practice, as well as contrived like hell. I'm pretty sure you can estimate it by counting the static data in the level on disk, then adding (as a "bad case") all sector and light thinkers, then doubling the mobj count for the ammo droppers, then adding a bit more margin. It may give me false positives, sure, but I can treat that as a warning.

[Xeriphas1994]

DeePsea has this feature under Check > Level Statistics.  No source code, sorry.

I learned the hard way to check first before practicing a vanilla max run.  :D

[riderr3]

Usually, when I creating vanilla maps, I lure many monster to one place and they shooting at me. Also I shoot on them from plasma gun. Then save, and look is there savegame limit or not.

But this kind of tool will be very useful for mappers.