Complete the overworld foundation

Port forced movement (turn delays, bumps, ice, currents, pits), dynamic
return warps, elevators, Surf, Cut, Strength and cycling rules, working
map blocks with changeblock/changemapblocks, and the remaining NPC
movement types and movement commands.

Add tileset animation from the ROM's command tables, grass sprite
priority and special map palettes; room decorations with ownership, the
bedroom PC and save migration; and Key Items access to the Bicycle.

Fourteen original-engine traces compare positions, facing, actors, event
flags and scripted poses. Tile animation matches original VRAM for four
tilesets, and LoadMapPals matches 192 palette cases. skyfall_top now
keeps the $60 sprite offset its step function leaves behind.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/game/rom/assets.ts

@@ -6,11 +6,13 @@ import {
   NATIVE_MAPS,
   NUM_ENGINE_FLAGS,
   NUM_SPRITEMOVEDATA,
+  OVERWORLD,
   RAM,
   SYMBOLS,
 } from "./profile";
 import { defaultTextContext, readString } from "../scripts/text";
 import { PokemonData } from "./pokemon";
+import { OW } from "../world/constants";
 import type {
   Direction,
   GameMap,
@@ -308,6 +310,35 @@ export class CrystalAssets {
       ];
     });
   }
+  /** LoadSpecialMapPalette: tilesets with their own eight palettes, which
+   * do not follow the time of day. */
+  private specialPalettes(map: GameMap): Palette[] | undefined {
+    const eight = (address: number) =>
+      Array.from({ length: 8 }, (_, i) => this.palette(address + i * 8));
+    switch (map.tileset) {
+      case OW.TILESET_POKECOM_CENTER:
+        return eight(OVERWORLD.PokeComPalette);
+      case OW.TILESET_BATTLE_TOWER_INSIDE:
+        return eight(OVERWORLD.BattleTowerInsidePalette);
+      case OW.TILESET_ICE_PATH:
+        // The Hall of Fame shares the tileset but is INDOOR.
+        return (map.environment & 7) === OW.INDOOR ? undefined : eight(OVERWORLD.IcePathPalette);
+      case OW.TILESET_HOUSE:
+        return eight(SYMBOLS.housePalettes);
+      case OW.TILESET_RADIO_TOWER:
+        return eight(OVERWORLD.RadioTowerPalette);
+      case OW.TILESET_MANSION: {
+        // LoadMansionPalette: MansionPalette1, then yellow from
+        // MansionPalette2, water from palette 6 and roof from palette 8.
+        const palettes = eight(OVERWORLD.MansionPalette1);
+        palettes[4] = this.palette(OVERWORLD.MansionPalette2);
+        palettes[3] = this.palette(OVERWORLD.MansionPalette1 + 6 * 8);
+        palettes[6] = this.palette(OVERWORLD.MansionPalette1 + 8 * 8);
+        return palettes;
+      }
+    }
+    return undefined;
+  }
   palettes(map: GameMap, time: number): Palette[] {
     const r = this.reader;
     const group =
@@ -316,13 +347,11 @@ export class CrystalAssets {
         r.bank(SYMBOLS.environmentColors),
       ) +
       time * 8;
-    const palettes = Array.from({ length: 8 }, (_, i) =>
-      this.palette(
-        map.tileset === 5
-          ? SYMBOLS.housePalettes + i * 8
-          : SYMBOLS.backgroundPalettes + r.byte(group + i) * 8,
-      ),
-    );
+    const palettes =
+      this.specialPalettes(map) ??
+      Array.from({ length: 8 }, (_, i) =>
+        this.palette(SYMBOLS.backgroundPalettes + r.byte(group + i) * 8),
+      );
     if (map.environment === 1 || map.environment === 2) {
       const roof = SYMBOLS.roofPalettes + map.group * 8 + (time >= 2 ? 4 : 0);
       const colors = this.palette(roof);
@@ -344,13 +373,15 @@ export class CrystalAssets {
     }
     throw new Error("Grass collision list is unterminated.");
   }
-  /** JohtoGrassWildMons for a map: encounter rates and seven slots per
-   * time of day (data/wild/johto_grass.asm). */
+  /** JohtoGrassWildMons or KantoGrassWildMons for a map: encounter rates
+   * and seven slots per time of day (data/wild/johto_grass.asm). */
   grassWildMons(
     id: string,
+    kanto = false,
   ): { rates: number[]; slots: { level: number; species: number }[][] } | undefined {
     const r = this.reader;
-    for (let p = SYMBOLS.johtoGrassWildMons, i = 0; i < 256; i++, p += 47) {
+    const table = kanto ? OVERWORLD.KantoGrassWildMons : SYMBOLS.johtoGrassWildMons;
+    for (let p = table, i = 0; i < 256; i++, p += 47) {
       const group = r.byte(p);
       if (group === 0xff) return undefined;
       if (`${group}:${r.byte(p + 1)}` !== id) continue;
@@ -365,6 +396,28 @@ export class CrystalAssets {
     }
     throw new Error("Wild encounter data is unterminated.");
   }
+  /** JohtoWaterWildMons or KantoWaterWildMons: one rate and three slots
+   * (data/wild/johto_water.asm). */
+  waterWildMons(
+    id: string,
+    kanto = false,
+  ): { rate: number; slots: { level: number; species: number }[] } | undefined {
+    const r = this.reader;
+    const table = kanto ? OVERWORLD.KantoWaterWildMons : OVERWORLD.JohtoWaterWildMons;
+    for (let p = table, i = 0; i < 256; i++, p += 9) {
+      const group = r.byte(p);
+      if (group === 0xff) return undefined;
+      if (`${group}:${r.byte(p + 1)}` !== id) continue;
+      return {
+        rate: r.byte(p + 2),
+        slots: Array.from({ length: 3 }, (_, slot) => ({
+          level: r.byte(p + 3 + slot * 2),
+          species: r.byte(p + 4 + slot * 2),
+        })),
+      };
+    }
+    throw new Error("Wild encounter data is unterminated.");
+  }
   /** Engine flags kept in the four bytes CheckDailyResetTimer clears
    * (wDailyFlags1 through wUnusedDailyFlag), from the ROM's EngineFlags. */
   dailyEngineFlags(): number[] {
@@ -381,13 +434,20 @@ export class CrystalAssets {
    * function, flags1 (FIXED_FACING, NOCLIP_*, ...) and palette flags. */
   spriteMovement(type: number): {
     fn: number;
+    /** OBJECT_ACTION_* the object starts with. */
+    action: number;
     flags: number;
     paletteFlags: number;
   } {
     if (type >= NUM_SPRITEMOVEDATA) throw new Error("Unknown movement type.");
     const r = this.reader,
       p = SYMBOLS.spriteMovementData + type * 6;
-    return { fn: r.byte(p), flags: r.byte(p + 3), paletteFlags: r.byte(p + 5) };
+    return {
+      fn: r.byte(p),
+      action: r.byte(p + 2),
+      flags: r.byte(p + 3),
+      paletteFlags: r.byte(p + 5),
+    };
   }
   /** Emote bubble graphics (data/sprites/emotes.asm). */
   emote(index: number): Uint8Array {
@@ -399,13 +459,25 @@ export class CrystalAssets {
       r.byte(entry + 2),
     );
   }
+  /** GetSprite: overworld sprites, and Pokémon drawn from their party
+   * menu icons (GetMonSprite). Variable sprites are resolved by the world
+   * from wVariableSprites first; day-care Pokémon are not ported. */
   sprite(id: number): Sprite | undefined {
-    // Variable decorations and Pokémon icons need separate decoders.
-    if (id < 1 || id >= 0xa0) return undefined;
     const cached = this.sprites.get(id);
     if (cached) return cached;
-    const r = this.reader,
-      p = SYMBOLS.sprites + (id - 1) * 6;
+    const r = this.reader;
+    if (id >= OW.SPRITE_POKEMON && id < OW.SPRITE_POKEMON + OW.NUM_POKEMON_SPRITES) {
+      // LoadOverworldMonIcon: eight tiles, two frames in the down and up
+      // standing slots, with palette 0.
+      const species = r.byte(OVERWORLD.SpriteMons + id - OW.SPRITE_POKEMON);
+      const icon = r.byte(OVERWORLD.MonMenuIcons + species - 1);
+      const pointer = r.near(OVERWORLD.IconPointers + icon * 2, r.bank(OVERWORLD.IconPointers));
+      const sprite = { graphics: r.slice(pointer, 8 * 16), palette: 0, walking: true };
+      this.sprites.set(id, sprite);
+      return sprite;
+    }
+    if (id < 1 || id > OW.NUM_OVERWORLD_SPRITES) return undefined;
+    const p = SYMBOLS.sprites + (id - 1) * 6;
     const length = r.byte(p + 2),
       walking = r.byte(p + 4) === 1;
     const sprite = {