DoomLite3D: taller walls, random maze, calm spawn, minimap

name: Maze and minimap overview: Replace the hand-drawn DoomLite3D level with a compact procedurally generated maze, raise walls by 50%, scatter enemies outside a calm spawn zone, and add a heading-up minimap in the top-right HUD corner. Regenerate the maze (and physics) on F1 restart. todos:

• id: wall-height

content: Raise LevelMap.WallHeight from 2f to 3f status: completed

• id: maze-generator

content: "Add MazeGenerator.cs: 21x21 backtracker, 5x5 calm spawn, optional path-length cap" status: completed

• id: level-create-random

content: Replace CreateDefault with CreateRandom + enemy scatter outside calm radius status: completed

• id: regenerate-lifecycle

content: "DoomLiteGame: RegenerateLevel on init and F1, rebuild BVH physics" status: completed

• id: minimap-hud

content: Add MinimapHud.cs (top-right, heading-up) and wire into draw loop status: completed isProject: false

Current state

• Level is a fixed ASCII layout in `LevelMap.CreateDefault()` (WallHeight = 2f, ~18×8 cells).
• `DoomLiteGame` holds one LevelMap for the session; F1 only resets player/enemies/combat, not the map or BVH.
• HUD already exposes HudRect / HudLine / HudText on `RayGameContext` (same pattern as XFighter radar in `CockpitHud.cs`).

flowchart LR
  MazeGenerator --> LevelMap
  LevelMap --> LevelRenderer
  LevelMap --> WallGridPhysics
  LevelMap --> EnemySystem
  PlayerController --> MinimapHud
  LevelMap --> MinimapHud
  EnemySystem --> MinimapHud

1. Wall height +50%

In `LevelMap.cs`:

• Change WallHeight from 2f to `3f` (2 × 1.5).
• No other edits needed: `LevelRenderer` and `WallGridPhysics.BuildWorld` already read LevelMap.WallHeight.

2. Procedural maze (compact, not sprawling)

Add `MazeGenerator.cs` in the app (dogfood-only; no novolis-math extraction unless you want it later).

Grid size: 21×21 cells (CellSize unchanged at 1f) — large enough to feel like a maze, small enough to cross in ~1–2 minutes.

Algorithm: recursive backtracker on odd coordinates inside a solid border:

1. Fill grid with walls (1).
2. Carve a calm spawn chamber first: e.g. 5×5 open floor anchored at (1,1) (inside border), record center as PlayerSpawn.
3. Start DFS from the chamber’s east-facing corridor cell; carve passages to odd (x,z) cells, removing walls between visited neighbors.
4. Result: guaranteed connected maze with an obvious safe starting room.

“Not too long” guard (optional but cheap): after carve, BFS from spawn; if longest path > ~40 cells, re-roll with a new seed (cap 8 attempts). Keeps dead-end sprawl bounded without huge maps.

Replace CreateDefault() with `LevelMap.CreateRandom(int? seed = null)` that calls MazeGenerator and returns LevelMap with DenseGrid<byte> walls + spawn + enemy list.

3. Enemy placement with calm start

In MazeGenerator (or a small EnemyPlacement helper in the same file):

• Enumerate all floor cells (walls == 0).
• Exclude calm zone: Manhattan distance from PlayerSpawn < 6 (covers the 5×5 room plus a short buffer corridor).
• From remaining cells, shuffle (seeded Random) and place enemies with:
• Target density ~20–30% of eligible cells (cap ~12–18 enemies on 21×21).
• Min spacing 3 cells between enemy positions (skip crowded picks).
• Alternate SpriteIndex 0/1 like today.

Remove the old ASCII 'e' parsing from LevelMap.

4. Regenerate level + physics on restart

Refactor `DoomLiteGame`:

• Change readonly LevelMap _level to mutable LevelMap _level.
• Extract RegenerateLevel():
• _level = LevelMap.CreateRandom();
• _physicsWorld = WallGridPhysics.BuildWorld(_level.Walls, LevelMap.CellSize, LevelMap.WallHeight);
• _player.SetPhysicsWorld(_physicsWorld);
• _player.Reset(_level); + _enemies.Reset(_level); + _combat.Reset();
• Call from Initialize and when F1 is pressed (new maze each restart).
• Pass _level into HUD draw for minimap (see below).

5. Minimap (top-right)

Add `MinimapHud.cs`:

Mapping: gridX = worldX / CellSize - 0.5, center minimap on player; scale cellPx = mapSize / max(width, height) (clamp so the whole map fits).

Wire from `WeaponHud.Draw` or call MinimapHud.Draw from DoomLiteGame after world pass — pass LevelMap, PlayerController, EnemySystem.

Avoid overlap with ammo text (bottom-right): minimap stays top-right (y = 16).

6. Small HUD copy tweak

Update control hint line if desired: mention F1 generates a new maze (optional one-line change in WeaponHud).

Files touched

No library changes in novolis-math / raylib / physics.

Verification

cd d:\novolis\novolis-dogfooding
dotnet build apps/DoomLite3D/DoomLite3D.csproj
dotnet run --project apps/DoomLite3D/DoomLite3D.csproj

Manual checks:

• Walls visibly taller (3m).
• Spawn room empty of enemies; enemies appear deeper in the maze.
• F1 produces a different layout.
• Minimap tracks movement, rotates with look, shows enemies.