Port evolution, Rare Candy, evolution stones and vitamins

Pokémon that levelled up evolve after a won battle, following
EvolveAfterBattle's checks over the ROM's evolution bytes, with the
evolution screen that B can stop and move learning outside battle. The pack
uses Rare Candy, stones (with ABLE/NOT ABLE labels) and vitamins, and its
pocket tabs now sit in their own row.

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

src/game/world/world.ts

@@ -28,6 +28,7 @@ import {
 } from "../scripts/interpreter";
 import { IntroRun } from "../scripts/intro";
 import { StartMenuRun, type MenuCursors } from "../scripts/start-menu";
+import { PartyEvolution } from "../scripts/evolution";
 import type { MovementPose, MovementStep } from "../scripts/movement";
 import { emptyBag, validBag, type Bag, type ItemSlot } from "../party/bag";
 import {
@@ -254,6 +255,26 @@ export interface BattleView {
   /** Yes/No cursor, as on the original boxes. */
   selected: 0 | 1;
 }
+/** EvolutionAnimation in overworld ticks (two frames each): 80 frames on
+ * the old species, then .AnimationSequence's seven rounds of a B-checking
+ * wait (14, 12 … 2 frames) followed by that many flashes of the new and
+ * old pictures (about four frames each). */
+function evolutionSchedule(from: number, to: number) {
+  const frames: { species: number; cancel: boolean }[] = [];
+  const show = (species: number, ticks: number, cancel = false) => {
+    for (let i = 0; i < ticks; i++) frames.push({ species, cancel });
+  };
+  show(from, 40);
+  for (let round = 1; round <= 7; round++) {
+    show(from, 8 - round, true);
+    for (let flash = 0; flash < round; flash++) {
+      show(to, 2);
+      show(from, 2);
+    }
+  }
+  return frames;
+}
+
 /** Ticks a `done` battle message stays before the battle continues. */
 const BATTLE_MESSAGE_TICKS = 30;
 
@@ -288,6 +309,12 @@ interface ActiveScript {
   warp?: { map: string; x: number; y: number; facing?: Direction };
   /** warpcheck: the player's tile events run on the tick after the script. */
   warpCheck?: boolean;
+  /** Routines that run before the script resumes with `result`: the
+   * evolutions ExitBattle starts after a won battle. */
+  interlude?: {
+    run: Generator<ScriptEffect, unknown, number | string | undefined>;
+    result: number;
+  };
   /** LoadMemScript: queued for the next PlayerEvents once this commits. */
   memScript?: MemScript;
   /** The trainer whose sight started this script, if any. */
@@ -479,6 +506,17 @@ export class GameWorld {
   picture: number | undefined;
   /** The introduction's trainer or player picture, if any. */
   portrait: Portrait | undefined;
+  /** An evolution animation in progress: the frame shown on each tick, and
+   * whether B may stop it then. */
+  evolution:
+    | {
+        from: number;
+        to: number;
+        cancelable: boolean;
+        step: number;
+        schedule: { species: number; cancel: boolean }[];
+      }
+    | undefined;
   /** True from a new game until the introduction finishes. */
   private introPending = false;
   /** The battle in progress, if any. */
@@ -1609,6 +1647,14 @@ export class GameWorld {
     this.pump();
   }
 
+  private evolutionHost() {
+    return {
+      reader: this.assets.reader,
+      data: this.assets.pokemon,
+      timeOfDay: () => this.clockTimeOfDay,
+      text: () => this.host(PLAYER).text(),
+    };
+  }
   /** Start in PlayerEvents (StartMenuScript): the start menu opens while
    * the player stands still. Its changes commit when it closes. */
   openStartMenu(): boolean {
@@ -1622,6 +1668,8 @@ export class GameWorld {
           data: this.assets.pokemon,
           text: () => this.host(PLAYER).text(),
           bicycleScript: (state) => this.bicycleScript(state),
+          timeOfDay: () => this.clockTimeOfDay,
+          landmark: () => this.assets.map(this.mapId).landmark,
         },
         this.menuCursors,
       ),
@@ -1679,8 +1727,21 @@ export class GameWorld {
     if (!script) return;
     try {
       for (;;) {
-        const effect = script.run.resume(input);
-        input = undefined;
+        let effect: ScriptEffect | undefined;
+        const interlude = script.interlude;
+        if (interlude) {
+          const next = interlude.run.next(input);
+          input = undefined;
+          if (next.done) {
+            script.interlude = undefined;
+            input = interlude.result;
+            continue;
+          }
+          effect = next.value;
+        } else {
+          effect = script.run.resume(input);
+          input = undefined;
+        }
         script.effect = effect;
         if (!effect) {
           this.finishScript();
@@ -1955,6 +2016,16 @@ export class GameWorld {
           },
         };
         return true;
+      case "evolve":
+        this.picture = effect.from;
+        this.evolution = {
+          from: effect.from,
+          to: effect.to,
+          cancelable: effect.cancelable,
+          step: 0,
+          schedule: evolutionSchedule(effect.from, effect.to),
+        };
+        return true;
       case "pack":
         this.dialogue = {
           pages: [""],
@@ -2350,6 +2421,7 @@ export class GameWorld {
     this.emote = undefined;
     this.picture = undefined;
     this.portrait = undefined;
+    this.evolution = undefined;
     if (script.sighted !== undefined)
       this.refusedSighting = {
         map: this.mapId,
@@ -2380,9 +2452,19 @@ export class GameWorld {
             );
           this.battle = undefined;
           this.battleRun = undefined;
-          // CleanUpBattleRAM
+          // ExitBattle: EvolveAfterBattle after a win, then CleanUpBattleRAM.
+          const { result, evolvable } = next.value;
           this.menuCursors = { start: 0, party: 0, pocket: 0 };
-          this.pump(next.value.result);
+          if (this.script && evolvable && !(result & 0x0f)) {
+            this.script.interlude = {
+              run: new PartyEvolution(
+                this.script.run.state,
+                this.evolutionHost(),
+              ).evolveAfterBattle(evolvable),
+              result,
+            };
+            this.pump();
+          } else this.pump(result);
           return;
         }
         const effect = next.value;
@@ -2793,6 +2875,13 @@ export class GameWorld {
     }
     const script = this.script;
     if (script) {
+      const evolution = this.evolution;
+      if (evolution) {
+        const frame = evolution.schedule[++evolution.step];
+        if (frame) this.picture = frame.species;
+        else this.finishEvolution(false);
+        return;
+      }
       const dialogue = this.dialogue;
       if (dialogue) {
         if (
@@ -3198,9 +3287,25 @@ export class GameWorld {
     )
       state.playerState = OW.PLAYER_NORMAL;
   }
+  /** EvolutionAnimation ends: the new species, or the old one if B
+   * stopped it. */
+  private finishEvolution(stopped: boolean) {
+    const evolution = this.evolution!;
+    this.evolution = undefined;
+    this.picture = stopped ? evolution.from : evolution.to;
+    this.pump(stopped ? 1 : 0);
+  }
   /** B, or A on a page without a choice. */
   advanceDialogue() {
     if (this.battle) return this.battleB();
+    const evolution = this.evolution;
+    if (evolution) {
+      // .WaitFrames_CheckPressedB: only between flashes, and never for a
+      // forced (evolution stone) evolution.
+      if (evolution.cancelable && evolution.schedule[evolution.step]?.cancel)
+        this.finishEvolution(true);
+      return;
+    }
     const dialogue = this.dialogue;
     if (!dialogue || !this.script) return;
     const last = dialogue.index === dialogue.pages.length - 1;
@@ -3587,9 +3692,11 @@ export class GameWorld {
     this.emote = undefined;
     this.picture = undefined;
     this.portrait = undefined;
+    this.evolution = undefined;
     this.battle = undefined;
     this.battleRun = undefined;
     this.memScript = undefined;
+    this.menuCursors = { start: 0, party: 0, pocket: 0 };
     this.clearNotice();
     this.introPending = false;
     // A save made during the introduction starts it again.