DoomLite3D: diagnostics, sparse rooms, boss, art

name: DoomLite polish pass overview: Add an F3 diagnostics overlay, sparse room-based level generation with pack/boss arenas and a ranged boss, higher enemy density, slightly wider corridors, committed Kenney-style art assets, and enemy HP so bosses feel tanky. todos:

• id: diagnostics-hud

content: "Add DiagnosticsHud (F3 toggle: FPS, frame ms, working set, GC heap, enemy counts, seed)" status: completed

• id: sparse-level-gen

content: "Refactor MazeGenerator to sparse room+MST layout: 55 grid, 3-wide corridors, dead space, pack/boss rooms" status: completed

• id: enemy-hp-boss

content: Enemy HP + WeaponDamage; boss scale/stats; BossBolt ranged attack with wall LOS status: completed

• id: spawn-tuning

content: Raise corridor scatter (~45%, max 38) and fixed pack-room spawns (4-6 per room) status: completed

• id: art-assets

content: Commit/generate imp, demon, brute, boss, weapon PNGs; optional room floor tint; update CREDITS and fetch script status: completed

• id: hud-minimap

content: Wire diagnostics in DoomLiteGame; update control hint; minimap room/boss markers status: completed isProject: false

Current state

• Level layout lives in `MazeGenerator.cs`: 35×35 grid, 11×11 logical perfect maze, 2-cell corridors (CarveLink* clears 2-wide), visits every logical node → map is mostly floor.
• Enemies are one-shot kills in `EnemySystem.TryHit` (enemy.Alive = false).
• HUD uses ctx.HudText / ctx.HudRect (`WeaponHud.cs`); F1 regen uses raw key 290 in `DoomLiteGame.cs`.
• Assets folder has `CREDITS.md` but no PNGs in tree right now — runtime falls back to glow spheres.

flowchart LR
  subgraph today [Today]
    MG[MazeGenerator perfect maze] --> LM[LevelMap]
    LM --> ES[EnemySystem one-shot]
  end
  subgraph target [Target]
    LG[LevelGenerator sparse rooms] --> LM2[LevelMap + RoomMeta]
    LM2 --> ES2[EnemySystem HP + boss bolts]
    DH[DiagnosticsHud F3] --> HUD[WeaponHud]
  end

1. Diagnostics overlay (F3 toggle)

New file: `DiagnosticsHud.cs`

• bool Visible toggled on F3 ((KeyboardKey)292, same pattern as F1).
• When visible, draw a semi-transparent panel (top-left, below health bar ~y=40) with:
• FPS: smoothed 1f / ctx.DeltaSeconds (EMA, e.g. α=0.1).
• Frame ms: ctx.DeltaSeconds * 1000.
• Working set: Process.GetCurrentProcess().WorkingSet64 / (1024*1024) MB.
• GC heap: GC.GetTotalMemory(false) / (1024*1024) MB (optional gen0 collections count).
• Enemies: alive / total.
• Level seed (once LevelMap exposes it — see §3).

Wire in `DoomLiteGame.Update`: toggle on key press; call DiagnosticsHud.Draw after _hud.Draw.

Update control hint in `WeaponHud.cs`: F3 diagnostics | F1 new maze | ....

No change to RayGame.Run global showFps — overlay stays in-app and toggleable.

2. Sparse room-based level generation

Replace the logical perfect-maze path in `MazeGenerator.cs` (or rename to LevelGenerator.cs and keep MazeGenerator.Generate as a thin forwarder for minimal churn).

Algorithm (deterministic from seed):

1. Fill grid with walls; carve calm 7×7 at (1,1) (unchanged spawn).
2. Sample 6 pack room centers + 1 boss center in interior (e.g. x,z ∈ [8, Size-10]), with min separation 10 cells and min distance from spawn 14.
3. Carve axis-aligned room rects; tag sites RoomKind.Pack / RoomKind.Boss.
4. Connect spawn + all rooms with a minimum spanning tree on room centers (Kruskal by Manhattan distance). For each edge, carve an L-shaped path (horizontal then vertical, or pick shorter split) using 3-cell-wide brush (CarveRect / Bresenham with perpendicular offset ±1).
5. Enemy placement:

• Pack rooms: place 4–6 EnemySpawn on random floor cells inside room (min spacing 2).
• Boss room: single EnemySpawn with EnemyKind.Boss.
• Corridors: existing scatter loop on floor cells outside calm exclusion, higher density cap.

1. Retain diameter guard (MaxDiameter) so sprawling stays bounded; bump limit slightly for larger grid (~70).

Dead space: unconnected regions stay wall by construction — no backtracker visit of full logical grid.

Level metadata: extend `LevelMap` with int Seed and optional IReadOnlyList<RoomRect> for minimap tinting (pack = amber dot, boss = red larger dot in `MinimapHud.cs`).

3. Enemy kinds, HP, and boss ranged attack

Types in `LevelMap.cs`:

enum EnemyKind { Grunt, Boss }
record struct EnemySpawn(GridIndex Cell, int SpriteIndex, EnemyKind Kind = EnemyKind.Grunt);

`Enemy` fields (`EnemySystem.cs`):

Combat: add PlayerCombatState.WeaponDamage = 15f; TryHit subtracts damage instead of Alive = false; death when Health <= 0.

Boss ranged (simple, no new physics package):

• List<BossBolt> on EnemySystem — position, velocity, TTL.
• When boss has LOS, player in 5–16 units, and RangedCooldown <= 0: spawn bolt from boss chest height toward player eye; speed ~5 u/s, lifetime 4s.
• Each frame: move bolt; wall stop via existing GridCollision2D.TryRaycastWall on XZ; player hit if within 0.9 units → combat.TakeDamage(10f) and remove bolt.
• Draw with existing ctx.DrawBolt (same as muzzle flash).
• Cooldown ~2.5s; boss still melees in close range.

Grunts remain melee-only (current behavior).

4. More art (committed assets)

Goal: visible billboards and slightly richer world without blocking on manual Kenney download.

1. Regenerate / commit PNGs under Assets/ (64×64, distinct silhouettes):

• enemies/imp.png, enemies/demon.png (grunt variants)
• enemies/brute.png (pack room bias)
• enemies/boss.png (large red/purple silhouette)
• weapon.png
• Optional: tiles/floor.png, tiles/wall.png for textured quads

Small build-time or script helper: scripts/generate-placeholder-assets.ps1 writes PNGs if missing (so CI clones work). Update `fetch-kenney-assets.ps1` to copy named Kenney files into those paths when zip is present.

1. Load in code:

• `EnemySystem.Initialize`: add brute.png, boss.png; map SpriteIndex / EnemyKind to texture; scale billboard per kind in Draw.
• `LevelRenderer.cs`: if floor/wall textures load, DrawTexturePro on a single large floor plane + per-wall billboards or keep colored boxes and only tint pack/boss room floors via one extra colored plane per room (lighter scope: floor tint quads in pack/boss rooms only).

1. Update `CREDITS.md` table with new files.

DoomLite3D.csproj already copies Assets\**\* — no csproj change needed.

5. Tuning summary

6. Tests and verification

• Manual: run dotnet run --project apps/DoomLite3D/DoomLite3D.csproj; F3 shows FPS/memory; F1 regen shows sparse map with isolated rooms; pack rooms have clusters; boss room at far end shoots and takes many hits.
• Optional unit test in dogfood test project (if exists): LevelGenerator produces connected spawn→boss BFS path and boss room floor area ≥ 81 cells.
• No novolis-math changes required unless corridor LOS tests are added later.

File touch list