Floor Generation Overview
This page goes over the of generation a single floor of a dungeon segment.
Overview
A dungeon map can generate without items, enemies, or traps. But at a bare minimum, a dungeon map must generate terrain (plus entrance/exit) in order to complete without errors. There are 4 main options on how to do this:
- Generate a Grid of Rooms, which is them converted into a connected List of Rooms, which are then used to generate tiles.
- Generate a connected List of Rooms, and then use those rooms to generate tiles.
- Generate Tiles directly.
- Load a Pre-made Map.
The type of floor gen you choose in the editor will dictate which options you have:
Grid of Rooms
Grid Floors are the most common approach to dungeon generation, with a large number of unique templates for floor shape. To use this approach, make the floor a GridFloorGen.
- It starts off by initializing a grid of cells using
InitGridPlanStep:
- Then, a path generator such as
GridPathBranchis run to place rooms in the grid (blue) with connecting halls between them (yellow):
Each room and hall filled in here are also assigned an algorithm at this step.
- The grid rooms and grid connectors are then translated into a list of rooms and halls, using
DrawGridToFloorStep.
It accomplishes this by first having each room algorithm then choose its size and location:
The rooms then signal their connection requirements to the halls, which then have their sizes chosen:
Then finally by writing it out to an actual list of rooms and halls:
- Then, the list of room and halls are then translated into tiles, using
DrawFloorToTileStep.
It accomplishes this by first asking each room to generate its tiles:
Then, the hall algorithms are asked to generate:
This leaves us with all floor tiles:
- Lastly, the start and end tile are marked, by first selecting 2 separate rooms and then choosing a tile in each room to put the marker. The step responsible for this is
FloorStairsStep
List of Rooms
To use this approach, make the floor a RoomFloorGen. Room Floors are somewhat uncommon and has few templates to choose from for floor shape. However it's possible to vary the floor shape a lot simply by choosing different room types to generate with.
Generating Tiles Directly
A direct tile generation algorithm would skip generating grids or rooms, and just generate the tiles directly, plus the start and end.
To use this approach, make the floor a StairsFloorGen. However, this algorithm has been rarely used and has existed mostly for debug rooms.
Pre-Made Map
To use this approach, make the floor a LoadGen. Pre-made maps are often used for fixed dungeon floors such as the reward rooms at the end of a dungeon, or secret rooms.
Priority System
Floor generation is broken down into an ordered list of steps, each assigned a priority. The priority determines at what point in the generation process the step should be performed, with a lower number means a step will execute earlier. While these priority numbers do not need to be obeyed for modding, they are the numbers that base PMDO uses.
Floor Data
Priority -6
Examples:
- MapDataStep
- MapEffectStep
- MapNameIDStep
- DefaultMapStatusStep
Grid Creation
Priority -5
Examples:
- InitGridPlanStep
Grid Path Generation
Priority -4
File:DungeonProcess Cells Chosen.png
Examples:
- GridPathBranch
- GridPathCircle
- GridPathTwoSides
- GridPathGrid
- GridPathBeetle
- GridPathTiered
- SetGridDefaultsStep
- ConnectGridBranchStep
- CombineGridRoomStep
Room List Creation
Priority -3
Examples:
- InitFloorPlanStep
- DrawGridToFloorStep
File:DungeonProcess Cells To Rooms.png File:DungeonProcess Cells To Rooms Halls.png File:DungeonProcess Rooms Halls.png
Room List Generation
Priority -2
Examples:
- FloorPathBranch
Tiles Creation
Priority -1
Examples:
- InitTilesStep
- DrawFloorToTileStep
File:DungeonProcess Rooms To Tiles.png File:DungeonProcess Rooms Halls To Tiles.png File:DungeonProcess Floor.png
Tiles Generation
Priority 0
Examples:
- SpecificTilesStep
Spawn Tables
Priority 1
Examples:
- MoneySpawnStep
- ItemSpawnStep (Priority 1.1)
- MobSpawnStep (Priority 1.2)
- TileSpawnStep (Priority 1.3)
Exits
Priority 2
Examples:
- FloorStairsStep
- StairsStep
Water
Priority 3
Examples:
- PerlinWaterStep
- BlobWaterStep
Textures
Priority 4
Used to be here because textures were actually placed here, but now only assigns textures to the map itself and lets the map compute them after ALL steps are done. Thus, this step is the least dependent on its current position in the steps.
Examples:
- MapTextureStep
- MapDictTextureStep
Tile Spawns
Priority 5
Examples:
- RandomSpawnStep
- DueSpawnStep
- TerminalSpawnStep
Spawns
Priority 6
Examples:
- All steps in Tile Spawns
- PlaceRandomMobsStep
- PlaceDisconnectedMobsStep
- PlaceNoLocMobsStep
Debug Checks
Priority 7
These gen steps are used to check the dungeon for issues, and throw an error if they're found. Useful for stress testing.
Examples:
- DetectIsolatedStairsStep
- DetectTileStep
