terrain

117 procedural dungeon/terrain generation algorithms in MoonBit.

Live Playground | Source

Install

moon add mizchi/terrain

Usage

Each algorithm is an independent package with a generate(config, rng) function.

fn main {
  let rng = @terrain/types.make_rng(42U)

  // 2D Grid algorithm
  let result = @terrain/bsp.generate(
    { width: 40, height: 20, min_room_size: 4, max_depth: 4 },
    rng,
  )
  println(result.grid.to_ascii())

  // Hex algorithm
  let rng = @terrain/types.make_rng(42U)
  let hex = @terrain/hex_maze.generate(
    { cols: 20, rows: 15, room_chance: 0.15 },
    rng,
  )
  println(hex.grid.to_ascii())

  // 3D multi-layer algorithm
  let rng = @terrain/types.make_rng(42U)
  let d3 = @terrain/multifloor_bsp.generate(
    { width: 40, height: 20, depth: 3, min_room_size: 4, stair_count: 3 },
    rng,
  )
  // Access each layer
  for z in 0..<d3.grid.depth {
    println("Layer " + z.to_string())
    println(d3.grid.to_ascii(z))
  }

  // Quarter View (isometric) algorithm
  let rng = @terrain/types.make_rng(42U)
  let iso = @terrain/iso_city.generate(
    { width: 40, height: 20, max_height: 8, building_density: 0.7, street_width: 2 },
    rng,
  )
  println(iso.grid.to_ascii())
  // Heights available via iso.grid.heights
}

Core Types

// Tile types
enum Tile { Floor; Wall; Door; LockedDoor; Key; Start; Goal; Corridor; Water; Empty }

// 2D grid (width x height)
struct Grid2D { width : Int; height : Int; cells : Array[Tile] }

// Hex grid (odd-r offset coordinates)
struct HexGrid { cols : Int; rows : Int; cells : Array[Tile]; orientation : Int }

// 3D multi-layer grid
struct Grid3D { width : Int; height : Int; depth : Int; layers : Array[Grid2D] }

// 2D grid with height data (for isometric rendering)
struct HeightGrid { width : Int; height : Int; cells : Array[Tile]; heights : Array[Int]; max_height : Int }

// Room descriptor
struct Room { x : Int; y : Int; w : Int; h : Int }

// Seeded RNG
struct RNG { .. }
fn make_rng(seed : UInt) -> RNG

Pattern

Every algorithm package follows the same pattern:

// Each package exports:
pub(all) struct XxxConfig { .. }     // Config with defaults
pub(all) struct XxxResult { .. }     // Result with grid + rooms
pub fn XxxConfig::default() -> XxxConfig
pub fn generate(config : XxxConfig, rng : @types.RNG) -> XxxResult

Import only what you need in moon.pkg.json:

{
  "import": [
    "mizchi/terrain/types",
    "mizchi/terrain/bsp",
    "mizchi/terrain/cellular"
  ]
}

Algorithms (117)

Maze (11)

#	Name	Package	Description
0	Maze (DFS)	maze	Recursive backtracker depth-first search
1	Eller's Maze	eller	Row-by-row generation with set merging
2	Kruskal's Maze	kruskal	Minimum spanning tree randomized maze
3	Binary Tree Maze	binary_tree	Two-direction bias with diagonal tendency
4	Sidewinder Maze	sidewinder	Horizontal runs with random vertical connections
5	Recursive Division	recursive_division	Recursive wall placement subdivision
6	Growing Tree	growing_tree	Tunable between DFS and Prim's via weight
7	Wilson's	wilson	Loop-erased random walk for uniform spanning tree
8	Aldous-Broder	aldous_broder	Random walk visiting every cell exactly once
9	Hunt and Kill	hunt_and_kill	Walk until stuck, then scan for unvisited neighbor
10	Pac-Man Maze	pacman	Bilaterally symmetric maze with central chamber

Room Placement (11)

#	Name	Package	Description
11	BSP Tree	bsp	Binary space partition with rooms in leaves
12	Poisson Disk	poisson	Blue noise distributed room placement
13	Rooms and Mazes	rooms_and_mazes	Place rooms then fill gaps with maze corridors
14	Rogue Classic	rogue	Grid-based room layout inspired by original Rogue
15	Room Accretion	accretion	Grow dungeon by adding rooms one at a time
16	TinyKeep	tinykeep	Random rooms with physics-based separation
17	Feature Growing	feature_growing	Grow by attaching rooms and corridors to exits
18	BFS Room Expansion	bfs_rooms	Seed-based parallel flood fill room growing
19	Prefab Assembly	prefab	Place predefined room templates randomly
20	Gravity Collapse	gravity_collapse	Drop rooms from top, stack with gravity simulation
21	Tetromino Packing	tetromino	Pack tetris-shaped pieces into grid

Cave / Organic (15)

#	Name	Package	Description
22	Cellular Automata	cellular	Conway-style birth/survival cave generation
23	Drunkard's Walk	drunkard	Random walker carving open space
24	Noise Caves	noise_caves	Value noise with octaves for smooth caves
25	DLA	dla	Diffusion-limited aggregation particle sticking
26	Marching Squares	marching_squares	Cellular automata with contour smoothing
27	Worm Tunnels	worm	Multiple directional worms carving passages
28	Erosion	erosion	Hydraulic erosion simulation on heightmap
29	Percolation	percolation	Random fill with connectivity phase transition
30	Ant Colony	ant_colony	Pheromone-guided ant swarm carving paths
31	Worley Noise	worley	Worley/cellular noise distance-based caves
32	Ridged Multifractal	ridged	Ridged multifractal noise with sharp ridges
33	Domain Warping	domain_warp	Noise with coordinate warping for organic shapes
34	Reaction-Diffusion	reaction_diffusion	Gray-Scott reaction-diffusion pattern formation
35	Slime Mold	slime_mold	Physarum-inspired slime mold agent simulation
36	Lightning	lightning	Lightning bolt branching path generation

Graph / Structure (10)

#	Name	Package	Description
37	Graph Grammar	graph_grammar	Rule-based graph rewriting with locks and keys
38	Diablo	diablo	Linear spine with branching side paths and loops
39	Spelunky	spelunky	Grid cells with guaranteed solution path
40	Arena Chain	arena_chain	Large arenas connected by narrow corridors
41	Cyclic Dungeon	cyclic_dungeon	Circular connectivity with key-gate puzzles
42	Metroidvania	metroidvania	Multi-zone layout with ability-gated connections
43	Mission Graph	mission_graph	Mission-driven node graph with lock progression
44	Ring Dungeon	ring	Ring corridor with rooms and Dark Souls shortcuts
45	Binding of Isaac	isaac	Grid-based room layout inspired by Isaac
46	Dead Cells	dead_cells	Branching biome path layout inspired by Dead Cells

Space Filling (4)

#	Name	Package	Description
47	Hilbert Curve	hilbert	Hilbert space-filling curve as corridor backbone
48	Gosper Curve	gosper	Flowsnake L-system curve on hex-like grid
49	Spiral	spiral	Archimedean spiral with rooms at intervals
50	Sierpinski Dungeon	sierpinski	Sierpinski carpet recursive subdivision

Terrain (5)

#	Name	Package	Description
51	Diamond-Square	diamond_square	Fractal heightmap with configurable roughness
52	Midpoint Displacement	midpoint_displacement	Multi-layer midpoint displacement terrain
53	Island/Archipelago	island	Circular islands connected by bridges
54	River/Watershed	river	Heightmap with hydraulic river carving
55	Crystal Growth	crystal	Axis-aligned crystal seed growth

Pattern / Tiling (7)

#	Name	Package	Description
56	WFC	wfc	Wave Function Collapse tile solver
57	Superimposition	superimpose	Overlapping random shape stamps
58	Herringbone Wang Tiles	herringbone	Herringbone pattern tile placement
59	L-System	lsystem	Lindenmayer system string rewriting paths
60	Hex Grid	hex_grid	Hexagonal cell grid with corridor connections
61	City Block	city_block	Street grid with buildings and dead ends
62	Penrose Tiling	penrose	Penrose-inspired aperiodic tiling dungeon

Hybrid (6)

#	Name	Package	Description
63	Voronoi Region	voronoi	Voronoi cell regions with edge corridors
64	Radial	radial	Concentric rings with spokes and gaps
65	Space Colonization	space_colonization	Attractor-based branching path growth
66	Parametric Tunnelers	tunneler	Multiple autonomous tunneling agents
67	Platformer Level	platformer	Side-scrolling level with platforms and ladders
68	Delaunay + Gabriel	delaunay	Delaunay triangulation with Gabriel graph pruning

Hex (10)

#	Name	Package	Grid	Description
69	Hex Maze	hex_maze	HexGrid	DFS maze on hexagonal grid
70	Hex CA	hex_ca	HexGrid	Cellular automata on hex grid
71	Hex Voronoi	hex_voronoi	HexGrid	Voronoi regions on hex grid
72	Hex WFC	hex_wfc	HexGrid	Wave Function Collapse on hex grid
73	Hex Spiral	hex_spiral	HexGrid	Spiral path on hex grid
74	Hex Territory	hex_territory	HexGrid	Faction territory expansion on hex grid
75	Hex River Delta	hex_river_delta	HexGrid	Branching river channels from center
76	Hex Fortress	hex_fortress	HexGrid	Concentric hex walls with gates and towers
77	Hex Biome	hex_biome	HexGrid	Voronoi biome regions with roads
78	Hex Snowflake	hex_snowflake	HexGrid	Fractal snowflake crystal pattern

3D Multi-Layer (10)

#	Name	Package	Grid	Description
79	Multi-Floor BSP	multifloor_bsp	Grid3D	BSP rooms on multiple floors with stairs
80	3D Drunkard	drunkard_3d	Grid3D	Random walk across layers
81	3D CA	cellular_3d	Grid3D	3D cellular automata caves
82	Vertical Shaft	vertical_shaft	Grid3D	Vertical shafts connecting horizontal rooms
83	Layered Caves	layered_caves	Grid3D	Connected cave systems across layers
84	3D Maze	maze_3d	Grid3D	Perfect maze with vertical passages
85	Underwater Base	underwater_base	Grid3D	Pressurized chambers with airlocks
86	Tree Roots	tree_roots	Grid3D	Organic branching roots descending through layers
87	Ant Nest 3D	ant_nest_3d	Grid3D	Ant colony with tunnels and chambers
88	Space Station	space_station	Grid3D	Ring habitat with central hub and spokes

Quarter View / Isometric (16)

#	Name	Package	Grid	Description
89	Isometric City	iso_city	HeightGrid	City blocks with variable building heights
90	Cliff Dungeon	cliff_dungeon	HeightGrid	Rooms carved into cliff faces
91	Layered Plateau	layered_plateau	HeightGrid	Eroded plateau terraces
92	Castle Generator	castle_gen	HeightGrid	Castle with towers, walls, and courtyards
93	Terraced Mines	terraced_mines	HeightGrid	Open-pit mine with ore veins
94	Floating Islands	floating_islands	HeightGrid	Sky islands connected by bridges
95	Ziggurat Temple	ziggurat	HeightGrid	Stepped pyramid with inner chambers
96	Canyon Ravine	canyon	HeightGrid	Deep canyon with bridges and caves
97	Harbor Town	harbor_town	HeightGrid	Coastal town with waterfront buildings
98	Tower Dungeon	tower_dungeon	HeightGrid	Vertical tower with stacked floors
99	Volcanic Crater	volcanic_crater	HeightGrid	Volcanic crater with lava vents
100	Amphitheater	amphitheater	HeightGrid	Tiered seating around central arena
101	Aqueduct	aqueduct	HeightGrid	Roman aqueduct with arched supports
102	Treehouse Village	treehouse	HeightGrid	Tree platforms connected by bridges
103	Mineshaft Elevator	mineshaft	HeightGrid	Central shaft with radiating tunnels
104	Glacier	glacier	HeightGrid	Ice field with crevasses and caves

Biome (6)

#	Name	Package	Description
105	Continent	continent	Ocean, beach, forest, mountain concentric rings
106	Dungeon Ecosystem	ecosystem	Cave to underground river to lava biome transition
107	Seasonal Forest	seasonal_forest	North-to-south tree density gradient
108	Swamp Labyrinth	swamp	Intertwined water channels and land paths
109	Desert Oasis	desert_oasis	Desert with scattered oases and caravan routes
110	Tundra Outpost	tundra	Frozen outposts connected by underground tunnels

Puzzle / Progression (6)

#	Name	Package	Description
111	Sokoban Layout	sokoban	Push-block puzzle grid rooms
112	One-Way Gate	oneway_gate	Directed tree dungeon with one-way doors
113	Teleporter Maze	teleporter	Disconnected room clusters linked by teleporters
114	Lock Cascade	lock_cascade	Deep key-lock chain progression
115	Gravity Puzzle	gravity_puzzle	Split gravity zones with inverted platforms
116	Mirror Dungeon	mirror_dungeon	Symmetric dungeon with corrupted mirror half

Development

# Install MoonBit
curl -fsSL https://cli.moonbitlang.com/install/unix.sh | bash

# Check
moon check --deny-warn --target js

# Test
moon test --target js

# Build web playground
moon build --target js

# Serve locally
python3 -m http.server 8080
# Open http://localhost:8080

License

Apache-2.0