Open Tin Tower and Whirl Islands: Suicune, Ho-Oh and Lugia (#32)

Tin Tower's floors and roof and the Whirl Islands are open. The Clear Bell
gets the player past the sages to Suicune in Tin Tower; after the League,
the Rainbow Wing leads up to Ho-Oh, and the Silver Wing to Lugia.

New specials: MonCheck and BeastsCheck (CheckOwnMonAnywhere, with its
five-letter OT comparison and no Day-Care search).

The playthrough driver plans ledge jumps for the later stages, waterfall
descents, warp panels and Surf between warps; the run gains two stages,
Routes 45 and 46 back to Ecruteak and Tin Tower's Suicune.

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

src/game/rom/profile.ts

@@ -1069,6 +1069,8 @@ export const JOHTO = {
   FindPartyMonThatSpecies: 0xc276,
   PlayCurMonCry: 0xc472,
   GiveDratini: 0x8b170,
+  BeastsCheck: 0x4a6e8,
+  MonCheck: 0x4a711,
   "GiveDratini.Movesets": 0x8b1c4,
   MoveDeletion: 0x2c547,
   "MoveDeletion.DeleterIntroText": 0x2c5ef,
@@ -1328,6 +1330,24 @@ export const NATIVE_MAPS: Record<string, string> = {
   "3:58": "Mt. Mortar",
   "3:59": "Mt. Mortar 2F",
   "3:60": "Mt. Mortar B1F",
+  "3:4": "Tin Tower 1F",
+  "3:5": "Tin Tower 2F",
+  "3:6": "Tin Tower 3F",
+  "3:7": "Tin Tower 4F",
+  "3:8": "Tin Tower 5F",
+  "3:9": "Tin Tower 6F",
+  "3:10": "Tin Tower 7F",
+  "3:11": "Tin Tower 8F",
+  "3:12": "Tin Tower 9F",
+  "15:12": "Tin Tower roof",
+  "3:66": "Whirl Islands",
+  "3:67": "Whirl Islands",
+  "3:68": "Whirl Islands",
+  "3:69": "Whirl Islands",
+  "3:70": "Whirl Islands",
+  "3:71": "Whirl Islands B1F",
+  "3:72": "Whirl Islands B2F",
+  "3:73": "Lugia’s chamber",
   "3:61": "Ice Path 1F",
   "3:62": "Ice Path B1F",
   "3:63": "Ice Path B2F",

src/game/scripts/interpreter.ts

@@ -73,6 +73,7 @@ import { displayUnownWords, hoOhChamber, omanyteChamber } from "./ruins";
 import { slotMachine } from "./slot-machine";
 import { cardFlip } from "./card-flip";
 import { giveDratini, moveDeletion } from "./blackthorn";
+import { beastsCheck, monCheck } from "./tin-tower";
 import {
   checkMagikarpLength,
   findPartyMonThatSpecies,
@@ -3426,6 +3427,10 @@ export class ScriptRun {
           this.specialContext(pages, take),
           this.state.magikarpRecord,
         );
+      case JOHTO.MonCheck:
+        return monCheck(this.specialContext(pages, take), value);
+      case JOHTO.BeastsCheck:
+        return beastsCheck(this.specialContext(pages, take));
       case JOHTO.GiveDratini:
         giveDratini(this.specialContext(pages, take), value);
         return value;

src/game/scripts/tin-tower.ts

@@ -0,0 +1,39 @@
+import type { SpecialContext } from "./special-context";
+
+const RAIKOU = 243,
+  ENTEI = 244,
+  SUICUNE = 245;
+
+/** CheckOwnMon's OT comparison: the first five characters, stopping at a
+ * terminator both names share (NAME_LENGTH_JAPANESE - 2 compares, then
+ * one more). */
+const sameOT = (ot: string, player: string) => {
+  const a = `${ot}@`,
+    b = `${player}@`;
+  for (let i = 0; i < 4; i++) {
+    if (a[i] !== b[i]) return false;
+    if (a[i] === "@") return true;
+  }
+  return a[4] === b[4];
+};
+
+/** CheckOwnMonAnywhere (engine/pokemon/search_owned.asm): a Pokémon of
+ * `species` with the player's ID and OT in the party or a box. An empty
+ * party finds nothing; the Day-Care is not searched. The party struct's
+ * species is read, so an Egg counts as its species. */
+export function ownsMon(c: SpecialContext, species: number) {
+  const { party, storage } = c.state;
+  if (!party.length) return false;
+  const player = c.player();
+  const owns = (mon: { species: number; otId: number; ot: string }) =>
+    mon.species === species && mon.otId === player.id && sameOT(mon.ot, player.name);
+  return party.some(owns) || storage.boxes.some((box) => box.some(owns));
+}
+
+/** MonCheck: 1 when the player owns a Pokémon of the species. */
+export const monCheck = (c: SpecialContext, species: number) =>
+  ownsMon(c, species) ? 1 : 0;
+
+/** BeastsCheck: 1 when the player owns Raikou, Entei and Suicune. */
+export const beastsCheck = (c: SpecialContext) =>
+  [RAIKOU, ENTEI, SUICUNE].every((species) => ownsMon(c, species)) ? 1 : 0;