Tilemaps are a new placeable asset type that is painted with autotiles in the scene view, with layers, brush, eraser and rectangle, and is drawn at runtime and in the export (#128)

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/core/store/serialize.ts

@@ -19,7 +19,15 @@ import {
 import { isParticleNodeDef } from '../particles/nodes';
 import { isShaderNodeDef } from '../shader/nodes';
 import { isKeyInterpolation, normalizeKeys } from '../model/animation';
-import type { AnimationKey, AnimationTrack, Asset, StateMachineAsset, TextureFrame } from '../model/Asset';
+import type {
+  AnimationKey,
+  AnimationTrack,
+  Asset,
+  StateMachineAsset,
+  TextureFrame,
+  TilemapLayer,
+} from '../model/Asset';
+import { parseCellKey } from '../model/tilemap';
 import { isAssetType } from '../model/AssetTypes';
 import { isFontFile } from '../model/font';
 import { isSoundFile } from '../model/sound';
@@ -175,6 +183,8 @@ export function deserializeProject(raw: unknown, fallbackId = ''): Project {
         (id): id is string => typeof id === 'string' && id !== '',
       );
       assets.push({ id, type, name, props, pictures });
+    } else if (type === 'tilemap') {
+      assets.push({ id, type, name, props, layers: normalizeLayers(a.layers) });
     } else if (type === 'animation') {
       // A root or row aiming at something gone is kept: it reads as missing and keeps its keys.
       const root = typeof a.root === 'string' ? a.root : '';
@@ -493,6 +503,26 @@ function normalizeTracks(raw: unknown): AnimationTrack[] {
   return tracks;
 }
 
+/**
+ * The layers of a tilemap. A cell whose key is not a pair of whole numbers, or which names nothing,
+ * is dropped; one naming a deleted autotile is kept, like an animation's dangling row, so an undo
+ * brings the drawing back. A doubled layer id is dropped as a doubled node is.
+ */
+function normalizeLayers(raw: unknown): TilemapLayer[] {
+  const layers: TilemapLayer[] = [];
+  for (const item of Array.isArray(raw) ? raw : []) {
+    const l = asRecord(item);
+    if (typeof l.id !== 'string' || !l.id || layers.some((o) => o.id === l.id)) continue;
+    const cells: Record<string, string> = {};
+    for (const [key, value] of Object.entries(asRecord(l.cells)))
+      if (parseCellKey(key) && typeof value === 'string' && value !== '') cells[key] = value;
+    const layer: TilemapLayer = { id: l.id, name: typeof l.name === 'string' ? l.name : 'Layer', cells };
+    if (l.hidden === true) layer.hidden = true;
+    layers.push(layer);
+  }
+  return layers;
+}
+
 function normalizeBag(raw: unknown, schema: PropertySchema, sparse: boolean): PropertyBag {
   const r = asRecord(raw);
   const bag: PropertyBag = {};