d2-map-investigation

A tool for investigating Diablo II map generation in the hopes of finding exploitable correlations between how things are generated (i.e. if a certain tile is found in X, then that means that Y will generate in a certain way). The ultimate goal is to find a way of knowing ahead-of-time which direction from the waypoint The Summoner will be in the Arcane Sanctuary.

Status:

• This started as a proof-of-concept just showing that map seeds can be programmatically iterated, and that their resulting levels/areas/tiles/presets/etc can be dumped/analyzed.
• The relevant code is in BH/MapInvestigation.cpp. See slashdiablo-maphack for reference on how the map data can be further dug into.

Usage

Requirements:

• Visual Studio 2017 (or newer, presumably)
• Diablo II v1.13c or v1.13d

Note: If you are using Diablo II v1.13d, then you need to define D2_VERSION_113D. This can be done by adding #define D2_VERSION_113D to the top of D2Ptrs.h

• Open BH.sln in Visual Studio and build it
• Open Diablo II and load into a game (doesn't work unless you're actually in a game)
• Run BH.Injector.exe from the Debug/ or Release/ directory (depending on your build mode)
  • If you run it from a command prompt, you can use BH.Injector.exe -p -o 2 to toggle injection and exit immediately
  • Otherwise, you use the interactive menu to choose how to inject BH.dll
• A console window will appear and start dumping the data
  • Once it's done, you can uninject
• .csv files will be created next to BH.dll (see Output below)

Note: I wasn't able to get BH.Injector to successfully inject when run through the Visual Studio debugger; it might be possible to get that to work

Output

All data is dumped to .csv files. Each of them have the seed as the first column.

arcane.csv

areas.positional.relationships.csv

Note: This is only useful for levels that connect without a 'warp' (i.e. Blood Moor to Cold Plains, but not Blood Moor to Den of Evil), and that happen to be in order in the internal level IDs. This direction does not take into account where actual exits are, its just comparing the starting coordinates of ID-sequential levels. Outputting the actual relationships between all actually connected areas using their actual exits would be a useful improvement to this data.

areas.rooms.csv

Note: 'Room' does refer to a colloquial room, it's just the term used for the large 'building blocks' of levels in D2

areas.rooms.presets.csv

Note: 'tile units' and 'room units' are probably the wrong name for these, but its to distinguish between the scale of coordinates used for rooms and the scale of coordinates used within a room

Finding Correlations / Progress

First attempt was to dump all presets (objects, monsters, tiles that always spawn in a given room) and look for any that fulfill all 3 of these conditions:

• Exist in all same-position arcane seeds
• Do not exist in any seeds with different arcane positions
• Are in Act 1 or 2

This ended up with no matching presets outside of things like The Summoner himself, Horazon's Journal, etc.

Running lua ../find_correlations.lua from with the Debug/ or Release/ directory (whichever you are using) will parse data.csv/arcane.csv and run the check described above.

Arcane Sanctuary TODO

• [x] Figure out how to determine which direction from the waypoint the summoner is from a generated Act
• [ ] Dump as much relevant information as possible for X amount of seeds (for levels in Act 1 and Act 2 before Arcane Sanctuary)
• [ ] Find correlations between Summoner direction and any of the dumped data and rank them
• [ ] Figure out if any of the found correlations are actually usable in a speedrun

Acknowledgements

The foundational code is a modified version of slashdiablo-maphack (specifically slippittydo's fork).