Expand Omokmaru AI to nine stronger levels

Author: Extransload

src/domains/games/renju/ai.ts

@@ -1,6 +1,23 @@
 import { analyzeMove, index, inside, SIZE, type Board, type Color, type Point } from './rules';
 
-export type Difficulty = 'easy' | 'normal' | 'hard' | 'master';
+export type Difficulty = 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9;
+
+const LEVELS: Record<Difficulty, { picks: number; depth: number; beam: number; time: number }> = {
+  1: { picks: 8, depth: 0, beam: 0, time: 0 },
+  2: { picks: 5, depth: 0, beam: 0, time: 0 },
+  3: { picks: 3, depth: 0, beam: 0, time: 0 },
+  4: { picks: 1, depth: 0, beam: 0, time: 0 },
+  5: { picks: 1, depth: 2, beam: 4, time: 300 },
+  6: { picks: 1, depth: 3, beam: 5, time: 850 },
+  7: { picks: 1, depth: 5, beam: 7, time: 2800 },
+  8: { picks: 1, depth: 7, beam: 8, time: 5000 },
+  9: { picks: 1, depth: 9, beam: 10, time: 8500 },
+};
+
+export function normalizeDifficulty(value: unknown): Difficulty {
+  const number = Number(value);
+  return Number.isInteger(number) && number >= 1 && number <= 9 ? (number as Difficulty) : 5;
+}
 const directions = [
   [1, 0],
   [0, 1],
@@ -72,7 +89,7 @@ function lineScore(board: Board, point: Point, color: Color): number {
         if (board[index(x, y)] === color) mine++;
         else blank++;
       }
-      if (!blocked && blank && mine >= 3) score += mine === 4 ? 1400 : 90;
+      if (!blocked && blank && mine >= 3) score += mine === 4 ? 5000 : 500;
     }
   }
   board[index(point.x, point.y)] = 0;
@@ -94,16 +111,25 @@ function ranked(board: Board, color: Color, search?: Search): Candidate[] {
   const cached = search?.positions.get(key);
   if (cached) return cached;
   const result: Candidate[] = [];
-  for (const point of candidates(board)) {
-    const verdict = analyzeMove(board, point.x, point.y, color);
+  const legality = new Map<string, ReturnType<typeof analyzeMove>>();
+  const scored = candidates(board)
+    .map((point) => {
+      const offense = lineScore(board, point, color);
+      const defense = lineScore(board, point, other(color));
+      const center = (7 - Math.abs(7 - point.x) + 7 - Math.abs(7 - point.y)) * 2;
+      return { point, offense, defense, center, score: offense + defense * 0.82 + center };
+    })
+    .sort((a, b) => b.score - a.score);
+  // Deep search spends its time on promising local moves while immediate wins
+  // and blocks stay at the front of the list through their five-in-a-row score.
+  const shortlist = search ? scored.slice(0, Math.max(18, search.beam * 2)) : scored;
+  for (const { point, offense, defense, center } of shortlist) {
+    const verdict = analyzeMove(board, point.x, point.y, color, legality);
     if (!verdict.legal) continue;
-    const offense = lineScore(board, point, color);
-    const defense = analyzeMove(board, point.x, point.y, other(color)).legal
-      ? lineScore(board, point, other(color))
-      : 0;
+    const legalDefense = analyzeMove(board, point.x, point.y, other(color), legality).legal ? defense : 0;
     result.push({
       point,
-      score: offense + defense * 0.82 + (7 - Math.abs(7 - point.x) + 7 - Math.abs(7 - point.y)) * 2,
+      score: offense + legalDefense * 0.82 + center,
       offense,
       win: verdict.win,
     });
@@ -179,26 +205,27 @@ function searchPosition(
 }
 
 export function chooseAiMove(board: Board, color: Color, difficulty: Difficulty): Point | null {
+  const level = LEVELS[normalizeDifficulty(difficulty)];
   const choices = ranked(board, color);
   if (!choices.length) return null;
   if (choices.length === 1) return choices[0].point;
   const winning = choices.find((choice) => choice.win);
   if (winning) return winning.point;
-  if (difficulty === 'easy') return choices[Math.floor(Math.random() * Math.min(6, choices.length))].point;
+  if (level.picks > 1) return choices[Math.floor(Math.random() * Math.min(level.picks, choices.length))].point;
   const threats = ranked(board, other(color)).filter((choice) => choice.win);
   const threatCells = new Set(threats.map((move) => index(move.point.x, move.point.y)));
   const roots = threats.length ? choices.filter((move) => threatCells.has(index(move.point.x, move.point.y))) : choices;
   if (!roots.length) return choices[0].point;
   if (roots.length === 1) return roots[0].point;
-  if (difficulty === 'normal') return roots[0].point;
+  if (!level.depth) return roots[0].point;
   const search: Search = {
-    deadline: Date.now() + (difficulty === 'master' ? 2800 : 850),
-    beam: difficulty === 'master' ? 7 : 5,
+    deadline: Date.now() + level.time,
+    beam: level.beam,
     positions: new Map(),
     transpositions: new Map(),
   };
   let best = roots[0];
-  const maximumDepth = difficulty === 'master' ? 5 : 3;
+  const maximumDepth = level.depth;
   for (let depth = 1; depth <= maximumDepth; depth++) {
     let iteration = best,
       bestScore = -Infinity,

src/domains/games/renju/solo.css

@@ -14,6 +14,12 @@
   color: #625f57;
   font-size: 12px;
 }
+.solo-ai-hint {
+  color: #77746c;
+  font-size: 11px;
+  line-height: 1.45;
+  margin-top: -10px;
+}
 .solo-field select,
 .segmented button {
   color: #294052;

src/domains/games/renju/solo.ts

@@ -1,12 +1,18 @@
 import { RenjuBoard, coordinate } from './board-3d';
 import { analyzeMove, boardFromMoves, openingMove, SIZE, type Color, type Move, type Point } from './rules';
-import type { Difficulty } from './ai';
+import { normalizeDifficulty } from './ai';
 import { mountRulesHelp } from './rules-help';
 import { mountMoveConfirm } from './move-confirm';
 import { mountGameSound } from './sound';
 import { appearanceForSeat, DEFAULT_APPEARANCE, watchAppearance, type Appearance } from './appearance';
 
 const $ = <T extends HTMLElement>(selector: string) => document.querySelector<T>(selector)!;
+const difficultySelect = $<HTMLSelectElement>('#difficulty');
+const savedDifficulty = localStorage.getItem('omokmaru:ai-level');
+if (savedDifficulty !== null) difficultySelect.value = String(normalizeDifficulty(savedDifficulty));
+difficultySelect.addEventListener('change', () => {
+  localStorage.setItem('omokmaru:ai-level', String(normalizeDifficulty(difficultySelect.value)));
+});
 const board = new RenjuBoard($('#canvas'));
 let appearance: Appearance = { ...DEFAULT_APPEARANCE };
 function applySeatAppearance() {
@@ -151,7 +157,7 @@ function aiTurn() {
   worker.postMessage({
     board: boardFromMoves(moves),
     color: player === 1 ? 2 : 1,
-    difficulty: $<HTMLSelectElement>('#difficulty').value as Difficulty,
+    difficulty: normalizeDifficulty(difficultySelect.value),
     id,
   });
 }

src/pages/playroom/omokmaru/solo.astro

@@ -47,7 +47,8 @@ import SeoHead from '../../../shared/components/SeoHead.astro';
         <div class="solo-settings">
           <strong>AI 대국</strong>
           <div class="solo-field"><span>내 돌</span><div class="segmented"><button id="side-black" class="selected" type="button">● 흑</button><button id="side-white" type="button">○ 백</button></div></div>
-          <label class="solo-field"><span>난이도</span><select id="difficulty"><option value="easy">쉬움</option><option value="normal" selected>보통</option><option value="hard">어려움</option><option value="master">마스터</option></select></label>
+          <label class="solo-field"><span>난이도</span><select id="difficulty"><option value="1">1단계 · 입문</option><option value="2">2단계</option><option value="3">3단계</option><option value="4">4단계</option><option value="5" selected>5단계 · 보통</option><option value="6">6단계</option><option value="7">7단계</option><option value="8">8단계</option><option value="9">9단계 · 최상</option></select></label>
+          <small class="solo-ai-hint">7~9단계는 깊게 수를 읽으며, 9단계는 최대 약 9초 생각합니다.</small>
           <button id="start" class="primary">대국 시작</button>
           <button id="resign-solo" class="secondary" hidden>기권</button>
           <button id="undo" class="secondary" hidden>↶ 한 수 되돌리기</button>

tests/e2e/layout.spec.ts

@@ -665,7 +665,7 @@ test('Playroom animations stay active under reduced motion', async ({ page }) =>
   await page.goto('/playroom/omokmaru/solo/');
   await expect(page.locator('#stage-overlay .overlay-card')).toHaveCSS('animation-name', 'overlay-enter');
   await page.locator('#side-white').click();
-  await page.locator('#difficulty').selectOption('easy');
+  await page.locator('#difficulty').selectOption('1');
   await page.locator('#start').click();
   await expect(page.locator('#status')).toHaveText('내 차례');
   await expect(page.locator('.player.active .piece')).toHaveCSS('animation-name', 'turn-piece-pulse');
@@ -758,7 +758,7 @@ test('solo match replaces start with resign until the match ends', async ({ page
 test('desktop board click places a stone immediately', async ({ page }) => {
   await page.goto('/playroom/omokmaru/solo/');
   await page.locator('#side-white').click();
-  await page.locator('#difficulty').selectOption('easy');
+  await page.locator('#difficulty').selectOption('1');
   await page.locator('#start').click();
   const canvas = page.locator('.canvas canvas');
   const box = await canvas.boundingBox();
@@ -773,7 +773,9 @@ test('desktop board click places a stone immediately', async ({ page }) => {
 
 test('solo board renders the AI reply after the player move', async ({ page }) => {
   await page.goto('/playroom/omokmaru/solo/');
-  await page.locator('#difficulty').selectOption('easy');
+  await expect(page.locator('#difficulty option')).toHaveCount(9);
+  await expect(page.locator('#difficulty')).toHaveValue('5');
+  await page.locator('#difficulty').selectOption('1');
   await page.locator('#start').click();
   await expect(page.locator('#canvas')).toHaveAttribute('data-rendered-moves', '2');
   const canvas = page.locator('.canvas canvas');
@@ -789,6 +791,25 @@ test('solo board renders the AI reply after the player move', async ({ page }) =
   await expect(page.locator('#canvas')).toHaveAttribute('data-rendered-moves', '2');
 });
 
+test('level nine AI finishes a searched reply', async ({ page }) => {
+  test.setTimeout(45_000);
+  await page.goto('/playroom/omokmaru/solo/');
+  await page.locator('#difficulty').selectOption('9');
+  await page.locator('#start').click();
+  await expect(page.locator('#canvas')).toHaveAttribute('data-rendered-moves', '2', { timeout: 20_000 });
+  await page.locator('.canvas canvas').focus();
+  for (let step = 0; step < 5; step++) {
+    await page.keyboard.press('ArrowRight');
+    if ((await page.locator('#board-keyboard-status').textContent())?.includes('빈 자리')) break;
+  }
+  await expect(page.locator('#board-keyboard-status')).toContainText('빈 자리');
+  await page.keyboard.press('Enter');
+  await expect(page.locator('#canvas')).toHaveAttribute('data-rendered-moves', '4', { timeout: 20_000 });
+  await expect(page.locator('#status')).toHaveText('내 차례');
+  await page.reload();
+  await expect(page.locator('#difficulty')).toHaveValue('9');
+});
+
 test('Omokmaru sound setting persists between visits', async ({ page }) => {
   await page.goto('/playroom/omokmaru/solo/');
   await page.locator('#sound').click();
@@ -938,7 +959,7 @@ test('Omokmaru studio puts the 3D preview before options on a phone', async ({ b
 test('keyboard can inspect coordinates and place a solo move', async ({ page }) => {
   await page.goto('/playroom/omokmaru/solo/');
   await page.locator('#side-white').click();
-  await page.locator('#difficulty').selectOption('easy');
+  await page.locator('#difficulty').selectOption('1');
   await page.locator('#start').click();
   const canvas = page.locator('.canvas canvas');
   await expect(canvas).toHaveAttribute('tabindex', '0');
@@ -991,7 +1012,7 @@ test('touch board tap previews a stone until the move button confirms it', async
   const page = await context.newPage();
   try {
     await page.goto('/playroom/omokmaru/solo/');
-    await page.locator('#difficulty').selectOption('easy');
+    await page.locator('#difficulty').selectOption('1');
     await page.locator('#start').click();
     const box = await page.locator('.canvas canvas').boundingBox();
     const center = { x: box!.x + box!.width / 2, y: box!.y + box!.height / 2 };

tests/games/renju-ai.test.ts

@@ -1,10 +1,14 @@
 import { describe, expect, it } from 'vitest';
-import { chooseAiMove } from '../../src/domains/games/renju/ai';
+import { chooseAiMove, normalizeDifficulty } from '../../src/domains/games/renju/ai';
 import { analyzeMove, boardFromMoves, emptyBoard, index, type Move } from '../../src/domains/games/renju/rules';
 
 describe('Renju AI', () => {
+  it('accepts exactly nine difficulty levels', () => {
+    for (let level = 1; level <= 9; level++) expect(normalizeDifficulty(String(level))).toBe(level);
+    for (const invalid of ['0', '10', '3.5', 'master', null]) expect(normalizeDifficulty(invalid)).toBe(5);
+  });
   it('opens at the required center point', () => {
-    for (const difficulty of ['easy', 'normal', 'hard', 'master'] as const)
+    for (const difficulty of [1, 2, 3, 4, 5, 6, 7, 8, 9] as const)
       expect(chooseAiMove(boardFromMoves([]), 1, difficulty)).toEqual({ x: 7, y: 7 });
   });
   it('takes an immediate legal win', () => {
@@ -18,7 +22,7 @@ describe('Renju AI', () => {
       { x: 10, y: 7, color: 1 },
       { x: 5, y: 2, color: 2 },
     ];
-    for (const difficulty of ['easy', 'normal', 'hard', 'master'] as const) {
+    for (const difficulty of [1, 2, 3, 4, 5, 6, 7, 8, 9] as const) {
       const point = chooseAiMove(boardFromMoves(moves), 1, difficulty);
       expect(point?.y).toBe(7);
       expect([6, 11]).toContain(point?.x);
@@ -28,7 +32,7 @@ describe('Renju AI', () => {
     const board = emptyBoard();
     for (const x of [7, 8, 9, 10]) board[index(x, 7)] = 2;
     board[index(6, 7)] = 1;
-    for (const difficulty of ['normal', 'hard', 'master'] as const)
+    for (const difficulty of [4, 5, 6, 7, 8, 9] as const)
       expect(chooseAiMove(board.slice(), 1, difficulty)).toEqual({ x: 11, y: 7 });
   });
   it('never selects a black double-three forbidden point', () => {
@@ -42,9 +46,9 @@ describe('Renju AI', () => {
       board[index(x, y)] = 1;
     expect(analyzeMove(board, 7, 7, 1).forbidden).toBe('double-three');
     const before = board.slice();
-    for (const difficulty of ['easy', 'normal', 'hard', 'master'] as const) {
+    for (const difficulty of [1, 4, 9] as const) {
       expect(chooseAiMove(board, 1, difficulty)).not.toEqual({ x: 7, y: 7 });
       expect(board).toEqual(before);
     }
-  });
+  }, 15_000);
 });