2048 · qwen3.6-27b
Build a playable 2048 game with arrow-key tile sliding and merging, smooth animations, a score, and win and lose states.
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Build a playable 2048 game with arrow-key tile sliding and merging, smooth animations, a score, and win and lose states.
thinking
The user wants me to build a fully self-contained 2048 game in a single HTML file. Let me plan this out: 1. **Game mechanics**: 4x4 grid, tiles slide and merge on arrow key input, new tile (2 or 4) spawns after each move, score tracking, win condition (reaching 2048), lose condition (no moves possible). 2. **UI**: Grid with tiles, score display, game over/win overlays. 3. **Animations**: CSS transitions for tile movement and merging. 4. **No external resources**: Everything inline. Let me build this carefully with proper game logic and smooth animations. Key implementation details: - Board represented as 4x4 array - Tile objects with positions, values, and animation state - CSS grid or absolute positioning for tiles - Slide animation using CSS transitions - Merge animation (scale up then settle) - Touch support would be nice but arrow keys are the requirement Let me write this as a complete, polished implementation.
/workspace/index.html (15213 bytes)Successfully wrote 15213 bytes to /workspace/index.html
thinking
Let me verify the file is correct and complete.
{"command":"wc -l /workspace/index.html && head -5 /workspace/index.html && echo \"---\" && tail -5 /workspace/index.html"}588 /workspace/index.html <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> --- initGame(); })(); </script> </body> </html>
thinking
The file is complete. Let me also verify there's no issue with the score update logic - I notice the `updateScore` function shows `+score` which would be the total score, not the score gained. Let me fix that detail, and also re-check the game logic for correctness. Actually, looking at the code more carefully, there's a bug in the score addition floating animation - it shows the total score rather than the score gained. Let me also double-check a subtle issue with the slide logic where a tile tries to move into a cell that has been marked for merge. Let me trace through the logic more carefully: In the slide function: 1. For each cell in the right order, get the tile id 2. Try to move it as far as possible in the direction 3. If empty, keep going 4. If same value and not merged this turn, merge 5. Otherwise stop The issue is that when we call `mergeTiles`, we set `grid[r][c] = null` for the original position, but the destination cell `grid[nr][nc]` still has the `existing` tile's id. Then later when the code checks `if (grid[tr][tc] === id)`, that won't match because we never updated `grid[nr][nc]` to be `id`. But actually the code path enters `mergeTiles` which handles both tiles - so the destination cell still has the target id, not the mover id. This looks correct actually. Wait, there's another issue. After the `while` loop, `tr, tc` are set. Then we check `if (grid[tr][tc] === id)`. If we merged, `grid[r][c] = null` was already set. And `grid[tr][tc]` (which is `grid[nr][nc]`) still has `existing`, not `id`. So the `if` won't match and we correctly fall through to the else branch (doing nothing). Good. If we moved into an empty space, then `grid[tr][tc]` is empty... wait, but we've been moving through `tr, tc` without updating `grid` until we finish the loop. So actually `grid[tr][tc]` might have a stale value or might be null. Hmm, this is a potential bug. Let me think more carefully... Actually, the way the code works: - We read `grid[r][c]` at the start to get the tile id - We compute `tr, tc` by looking at `grid[nr][nc]` throughout - If we find an empty spot (`grid[nr][nc]` is null), we advance - If we find a mergeable spot, we merge and clear `grid[r][c]` - After the loop, if we moved but didn't merge, the destination cell `grid[tr][tc]` is null (it was empty), so `grid[tr][tc] === id` would be `null === id` which is false That's a bug! When moving to an empty cell, we need `grid[tr][tc] = null` initially, so `grid[tr][tc] === id` fails, and we don't move the tile. Let me fix this. Let me rewrite the slide logic to be clearer. I'll use a different approach: process rows/columns as arrays of [value, id] pairs, similar to the original 2048 implementation approach. Let me rewrite this properly.
I notice a logic bug in the tile sliding code. Let me fix it with a cleaner approach:
{"content":"<!DOCTYPE html>\n<html lang=\"en\">\n<head>\n<meta charset=\"UTF-8\">\n<meta name=\"viewport\" content=\"width=device-width, iniValidation failed for tool "write": - path: must have required properties path Received arguments: { "content": "<!DOCTYPE html>\n<html lang=\"en\">\n<head>\n<meta charset=\"UTF-8\">\n<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\n<title>2048</title>\n<style>\n * { margin: 0; padding: 0; box-sizing: border-box; }\n\n body {\n font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;\n background: #faf8ef;\n display: flex;\n justify-content: center;\n align-items: center;\n min-height: 100vh;\n user-select: none;\n overflow: hidden;\n }\n\n #game-container {\n width: 460px;\n text-align: center;\n }\n\n #header {\n display: flex;\n justify-content: space-between;\n align-items: center;\n margin-bottom: 20px;\n }\n\n h1 {\n font-size: 64px;\n font-weight: 800;\n color: #776e65;\n }\n\n .score-box {\n background: #bbada0;\n border-radius: 8px;\n padding: 8px 20px;\n text-align: center;\n min-width: 100px;\n position: relative;\n }\n\n .score-box .label {\n font-size: 13px;\n font-weight: 600;\n color: #eee4da;\n text-transform: uppercase;\n letter-spacing: 1px;\n }\n\n .score-box .value {\n font-size: 26px;\n font-weight: 700;\n color: #fff;\n }\n\n .score-float {\n position: absolute;\n top: -20px;\n left: 50%;\n transform: translateX(-50%);\n font-size: 20px;\n font-weight: 700;\n color: #776e65;\n animation: scoreFloat 0.7s ease-out forwards;\n pointer-events: none;\n }\n\n @keyframes scoreFloat {\n 0% { opacity: 1; transform: translateX(-50%) translateY(0); }\n 100% { opacity: 0; transform: translateX(-50%) translateY(-40px); }\n }\n\n #sub-header {\n display: flex;\n justify-content: space-between;\n align-items: center;\n margin-bottom: 20px;\n }\n\n #sub-header p {\n color: #776e65;\n font-size: 16px;\n }\n\n #new-game-btn {\n background: #8f7a66;\n color: #f9f5f2;\n border: none;\n border-radius: 6px;\n padding: 10px 20px;\n font-size: 16px;\n font-weight: 700;\n cursor: pointer;\n transition: background 0.2s;\n }\n\n #new-game-btn:hover { background: #9f8b77; }\n\n #board-wrapper {\n position: relative;\n width: 460px;\n height: 460px;\n background: #bbada0;\n border-radius: 12px;\n padding: 12px;\n }\n\n #grid {\n display: grid;\n grid-template-columns: repeat(4, 1fr);\n grid-template-rows: repeat(4, 1fr);\n gap: 12px;\n width: 100%;\n height: 100%;\n }\n\n .cell {\n background: rgba(238, 228, 218, 0.35);\n border-radius: 8px;\n }\n\n #tile-layer {\n position: absolute;\n top: 0; left: 0;\n width: 100%;\n height: 100%;\n pointer-events: none;\n }\n\n .tile {\n position: absolute;\n width: 102px;\n height: 102px;\n border-radius: 8px;\n display: flex;\n justify-content: center;\n align-items: center;\n font-size: 52px;\n font-weight: 700;\n transition: top 0.15s ease-in-out, left 0.15s ease-in-out;\n z-index: 10;\n }\n\n .tile.new {\n animation: tileAppear 0.25s ease-out;\n }\n\n .tile.merged {\n animation: tileMerge 0.2s ease-in-out;\n z-index: 20;\n }\n\n @keyframes tileAppear {\n 0% { transform: scale(0); opacity: 0; }\n 100% { transform: scale(1); opacity: 1; }\n }\n\n @keyframes tileMerge {\n 0% { transform: scale(1); }\n 50% { transform: scale(1.25); }\n 100% { transform: scale(1); }\n }\n\n .tile-2 { background: #eee4da; color: #776e65; }\n .tile-4 { background: #ede0c8; color: #776e65; }\n .tile-8 { background: #f2b179; color: #f9f5f2; }\n .tile-16 { background: #f59563; color: #f9f5f2; }\n .tile-32 { background: #f67c5f; color: #f9f5f2; }\n .tile-64 { background: #f65e3b; color: #f9f5f2; }\n .tile-128 { background: #edcf72; color: #f9f5f2; font-size: 42px; }\n .tile-256 { background: #edcc61; color: #f9f5f2; font-size: 42px; }\n .tile-512 { background: #edc850; color: #f9f5f2; font-size: 42px; }\n .tile-1024 { background: #edc53f; color: #f9f5f2; font-size: 34px; }\n .tile-2048 { background: #edc22e; color: #f9f5f2; font-size: 34px; box-shadow: 0 0 30px 10px rgba(237,194,46,.3), inset 0 0 0 1px rgba(255,255,255,.15); }\n .tile-super { background: #3c3a32; color: #f9f5f2; font-size: 28px; }\n\n .overlay {\n position: absolute;\n top: 0; left: 0;\n width: 100%; height: 100%;\n background: rgba(238, 228, 218, 0.73);\n border-radius: 12px;\n display: flex;\n flex-direction: column;\n justify-content: center;\n align-items: center;\n z-index: 100;\n opacity: 0;\n pointer-events: none;\n transition: opacity 0.3s ease;\n }\n\n .overlay.active {\n opacity: 1;\n pointer-events: auto;\n }\n\n .overlay.win { background: rgba(237, 194, 46, 0.5); }\n\n .overlay h2 {\n font-size: 48px;\n font-weight: 800;\n color: #776e65;\n margin-bottom: 16px;\n }\n\n .overlay.win h2 { color: #edc22e; }\n\n .overlay button {\n background: #8f7a66;\n color: #f9f5f2;\n border: none;\n border-radius: 6px;\n padding: 12px 28px;\n font-size: 18px;\n font-weight: 700;\n cursor: pointer;\n margin-top: 8px;\n transition: background 0.2s;\n }\n\n .overlay button:hover { background: #9f8b77; }\n</style>\n</head>\n<body>\n<div id=\"game-container\">\n <div id=\"header\">\n <h1>2048</h1>\n <div class=\"score-box\" id=\"score-box\">\n <div class=\"label\">Score</div>\n <div class=\"value\" id=\"score\">0</div>\n </div>\n <div class=\"score-box\">\n <div class=\"label\">Best</div>\n <div class=\"value\" id=\"best\">0</div>\n </div>\n </div>\n <div id=\"sub-header\">\n <p>Join the tiles, get to <b>2048</b>!</p>\n <button id=\"new-game-btn\">New Game</button>\n </div>\n <div id=\"board-wrapper\">\n <div id=\"grid\">\n <div class=\"cell\"></div><div class=\"cell\"></div><div class=\"cell\"></div><div class=\"cell\"></div>\n <div class=\"cell\"></div><div class=\"cell\"></div><div class=\"cell\"></div><div class=\"cell\"></div>\n <div class=\"cell\"></div><div class=\"cell\"></div><div class=\"cell\"></div><div class=\"cell\"></div>\n <div class=\"cell\"></div><div class=\"cell\"></div><div class=\"cell\"></div><div class=\"cell\"></div>\n </div>\n <div id=\"tile-layer\"></div>\n <div class=\"overlay\" id=\"win-overlay\">\n <h2>You Win! 🎉</h2>\n <button id=\"keep-btn\">Keep Playing</button>\n <button id=\"win-new-btn\">New Game</button>\n </div>\n <div class=\"overlay\" id=\"lose-overlay\">\n <h2>Game Over</h2>\n <button id=\"lose-new-btn\">Try Again</button>\n </div>\n </div>\n</div>\n\n<script>\n(function() {\n const SIZE = 4;\n const TILE_SIZE = 102;\n const GAP = 12;\n const PAD = 12;\n\n let grid = []; // grid[r][c] = tileId or null\n let tiles = {}; // tiles[id] = { el, value, r, c }\n let score = 0;\n let best = parseInt(localStorage.getItem('best2048') || '0');\n let nextId = 0;\n let won = false;\n let keepPlaying = false;\n let gameOver = false;\n let busy = false;\n\n const tileLayer = document.getElementById('tile-layer');\n const scoreEl = document.getElementById('score');\n const bestEl = document.getElementById('best');\n const winOvl = document.getElementById('win-overlay');\n const loseOvl = document.getElementById('lose-overlay');\n const scoreBox = document.getElementById('score-box');\n\n bestEl.textContent = best;\n\n function pixelPos(r, c) {\n return { top: PAD + r * (TILE_SIZE + GAP), left: PAD + c * (TILE_SIZE + GAP) };\n }\n\n function setPos(el, r, c) {\n const p = pixelPos(r, c);\n el.style.top = p.top + 'px';\n el.style.left = p.left + 'px';\n }\n\n // --- Grid helpers ---\n\n function blankGrid() {\n const g = [];\n for (let r = 0; r < SIZE; r++) { g[r] = []; for (let c = 0; c < SIZE; c++) g[r][c] = null; }\n return g;\n }\n\n function emptyCells() {\n const out = [];\n for (let r = 0; r < SIZE; r++) for (let c = 0; c < SIZE; c++) if (!grid[r][c]) out.push([r, c]);\n return out;\n }\n\n function spawnTile() {\n const cells = emptyCells();\n if (!cells.length) return null;\n const [r, c] = cells[Math.floor(Math.random() * cells.length)];\n const v = Math.random() < 0.9 ? 2 : 4;\n return createTile(++nextId, v, r, c, true);\n }\n\n function createTile(id, value, r, c) {\n const el = document.createElement('div');\n el.className = `tile tile-${value <= 2048 ? value : 'super'} new`;\n el.textContent = value;\n setPos(el, r, c);\n tileLayer.appendChild(el);\n const t = { el, value, r, c };\n tiles[id] = t;\n grid[r][c] = id;\n return t;\n }\n\n function setTileClass(el, value) {\n const cls = value <= 2048 ? `tile-${value}` : 'tile-super';\n // Remove all tile value classes\n el.className = el.className.replace(/tile-\\d+|tile-super/g, '').trim();\n el.classList.add('tile', cls);\n if (value > 999) el.style.fontSize = value > 9999 ? '24px' : '34px';\n else if (value > 99) el.style.fontSize = '42px';\n else el.style.fontSize = '52px';\n el.textContent = value;\n }\n\n // --- Scoring ---\n\n function addScore(s) {\n score += s;\n scoreEl.textContent = score;\n if (score > best) { best = score; localStorage.setItem('best2048', best); }\n bestEl.textContent = best;\n // Floating score indicator\n const floater = document.createElement('div');\n floater.className = 'score-float';\n floater.textContent = '+' + s;\n scoreBox.appendChild(floater);\n setTimeout(() => floater.remove(), 700);\n }\n\n // --- Core slide logic ---\n\n // Extract a line (row or column) as an array of tile-ids\n function line(r, c, dr, dc, len) {\n const out = [];\n for (let i = 0; i < len; i++) { out.push(grid[r + i * dr][c + i * dc]); }\n return out;\n }\n\n // Get one row or column, slide it, return { moves: [{from, to, mergeTo}], scores }\n function slideOneArr(ids) {\n // ids: array of 4 elements, each null or a tile-id\n // Step 1: compress (remove nulls)\n const nonNull = ids.map(id => ({ id, visited: false })).map(x => x).filter(x => x.id !== null);\n\n // Step 2: merge adjacent equals (left-to-right)\n const merged = [];\n let scoreGain = 0;\n for (let i = 0; i < nonNull.length; i++) {\n const cur = nonNull[i];\n if (merged.length > 0 && !merged[merged.length - 1].skipMerge &&\n !cur.visited && tiles[cur.id] && tiles[cur.id].value === tiles[merged[merged.length - 1].id].value) {\n merged[merged.length - 1].skipMerge = true;\n cur.visited = true;\n scoreGain += tiles[cur.id].value * 2;\n }\n merged.push(cur);\n if (cur.visited) merged.pop(); // remove visited (merged) items\n }\n\n // Step 3: pad to SIZE\n while (merged.length < SIZE) merged.push(null);\n\n return { result: merged, scoreGain };\n }\n\n function buildLineMap(r, c, dr, dc, ids, result) {\n // return array of { id: tileId, r, c } for each position that changed\n const actions = [];\n for (let i = 0; i < SIZE; i++) {\n const nr = r + i * dr;\n const nc = c + i * dc;\n const oldId = ids[i];\n const newEntry = result[i];\n const newId = newEntry ? newEntry.id : null;\n if (oldId !== newId) {\n if (oldId !== null && newId !== null && newEntry && newEntry.visited) {\n // This old tile was merged into another. Track it separately.\n actions.push({ type: 'merge', moverId: oldId, targetId: newId, nr, nc });\n } else if (oldId !== null && newId === null) {\n actions.push({ type: 'remove', id: oldId });\n } else if (oldId === null && newId !== null) {\n // tile slid here (won't happen in practice when we use id mapping)\n }\n }\n // Mark the grid position\n }\n }\n\n let animating = false;\n\n function doSlide(dr, dc) {\n if (animating || gameOver) return;\n\n // Determine traversal order: process the \"far\" side first\n const rOrder = dr === 1 ? [3, 2, 1, 0] : [0, 1, 2, 3];\n const cOrder = dc === 1 ? [3, 2, 1, 0] : [0, 1, 2, 3];\n\n let anyMove = false;\n let totalScore = 0;\n\n // Collect all actions to perform after processing\n const allMoves = []; // { id, fromR, fromC, toR, toC }\n const allMerges = []; // { moverId, targetId, toR, toC }\n const newGrid = blankGrid();\n\n for (const r of rOrder) {\n for (const c of cOrder) {\n // We won't iterate this way; instead, process each line.\n }\n }\n\n // Better approach: process each line independently\n const lines = [];\n for (const r of rOrder) {\n for (const c of cOrder) {\n // Only process leading cells of each line\n if (dr === 0 && c === 0) {} // process all rows\n }\n }\n\n // Actually, let's just process all 8 lines (4 rows + 4 cols) but only once each\n // For up/down: process columns with dr; for left/right: process rows with dc\n const lineStarts = [];\n if (dr !== 0) {\n // vertical: for each column, start at row 0 or 3\n for (let c = 0; c < SIZE; c++) {\n lineStarts.push({ r: dr < 0 ? 0 : SIZE - 1, c, dr, dc, len: SIZE });\n }\n } else {\n // horizontal\n for (let r = 0; r < SIZE; r++) {\n lineStarts.push({ r, c: dc < 0 ? 0 : SIZE - 1, dr, dc, len: SIZE });\n }\n }\n\n for (const { r, c, dr: ld, dc: lcd, len } of lineStarts) {\n // Tail the line from far end toward near end\n const farStartR = ld < 0 ? SIZE - 1 : 0;\n const lineIds = [];\n for (let i = 0; i < len; i++) {\n lineIds.push(grid[ld < 0 ? (SIZE - 1 - i) : i + r][lcd < 0 ? (SIZE - 1 - i) : i + c]);\n }\n // Hmm, this is getting complicated. Let me just use a simpler approach.\n }\n\n // Reset after detour; use the clean approach\n // Process each of 4 lines in the direction of movement\n const linesToProcess = [];\n if (dr !== 0) {\n for (let c = 0; c < SIZE; c++) {\n // Column c, direction dr\n const ids = [];\n const positions = [];\n if (dr < 0) {\n // Moving up: process from row 0 down to 3\n for (let i = 0; i < SIZE; i++) {\n ids.push(grid[i][c]);\n positions.push([i, c]);\n }\n } else {\n // Moving down: process from row 3 up to 0\n for (let i = SIZE - 1; i >= 0; i--) {\n ids.push(grid[i][c]);\n positions.push([i, c]);\n }\n }\n linesToProcess.push({ ids, positions });\n }\n } else {\n for (let r = 0; r < SIZE; r++) {\n const ids = [];\n const positions = [];\n if (dc < 0) {\n for (let i = 0; i < SIZE; i++) {\n ids.push(grid[r][i]);\n positions.push([r, i]);\n }\n } else {\n for (let i = SIZE - 1; i >= 0; i--) {\n ids.push(grid[r][i]);\n positions.push([r, i]);\n }\n }\n linesToProcess.push({ ids, positions });\n }\n }\n\n // Now process each line\n for (const { ids, positions } of linesToProcess) {\n const { result, scoreGain } = slideOneArr(ids);\n // Map results back to positions\n for (let i = 0; i < SIZE; i++) {\n const [tr, tc] = positions[i];\n const entry = result[i];\n const newId = entry ? entry.id : null;\n const oldId = ids[i];\n\n if (entry && entry.visited) {\n // This tile was merged. It slides to position i, then disappears.\n // The previous non-visited tile at i-1 (or wherever) absorbs it.\n allMerges.push({ moverId: newId, targetId: result[rFindMerge(result, i)] ? result[rFindMerge(result, i)].id : null, toR: tr, toC: tc });\n // Actually we need to figure out which tile absorbed this one\n } else if (newId !== oldId) {\n if (oldId !== null && newId === null) {\n // Tile moved away from this position (it went earlier in the line)\n }\n if (newId !== null && oldId === null) {\n // Tile slid into an empty spot\n allMoves.push({ id: newId, fromR: tiles[newId].r, fromC: tiles[newId].c, toR: tr, toC: tc });\n }\n if (newId !== null && oldId !== null && newId !== oldId) {\n // Two tiles at the same spot = merge case handled above, or same tile\n }\n }\n }\n }\n\n // This is getting way too convoluted. Let me just rewrite from scratch with a clean approach.\n // Canceling this approach...\n }\n\n // ============================================================\n // CLEAN REWRITE of slide logic\n // ============================================================\n\n function updateTileVisual(id) {\n const t = tiles[id];\n if (!t) return;\n setTileClass(t.el, t.value);\n }\n\n function slideGrid(dr, dc) {\n // dr, dc each in {-1, 0, 1}, exactly one non-zero\n if (busy || gameOver) return;\n\n // We'll process the board in the correct order\n // For left (dc=-1): cols 0..3, for each col process rows 0..3\n // For right (dc=1): cols 3..0, for each col process rows 0..3\n // For up (dr=-1): rows 0..3, for each row process cols 0..3\n // For down (dr=1): rows 3..0, for each row process cols 0..3\n // Within each line, we process from the leading edge outward\n\n const rowOrder = dr === 1 ? [3,2,1,0] : [0,1,2,3];\n const colOrder = dc === 1 ? [3,2,1,0] : [0,1,2,3];\n\n let moved = false;\n let scoreGain = 0;\n const pushes = []; // { id, r, c } — slide a tile to (r,c)\n const mergers = []; // { moverId, targetId, r, c } — merge mover into target at (r,c)\n\n for (const ri of (dr ? rowOrder : [0,1,2,3])) {\n for (const ci of (dc ? colOrder : [0,1,2,3])) {\n // Only process \"root\" cells of each line\n if (dr !== 0 && ci !== 0) continue;\n if (dc !== 0 && ri !== 0) continue;\n\n const startR = dr !== 0 ? ri : ri;\n const startC = dc !== 0 ? ci : ci;\n\n // Trace the line\n for (let step = 0; step < SIZE - 1; step++) {\n const cr = startR + step * dr;\n const cc = startC + step * dc;\n const nid = grid[cr][cc];\n if (!nid) continue;\n\n // Try to push this tile as far as possible\n let bestPos = null;\n let bestMerge = null;\n\n for (let scan = step + 1; scan < SIZE; scan++) {\n const sr = startR + scan * dr;\n const sc = startC + scan * dc;\n const sid = grid[sr][sc];\n\n if (!sid) {\n bestPos = { r: sr, c: sc };\n continue;\n }\n\n // Adjacent tile in this line\n // Check if it's the same value and already part of this line\n // by verifying its original position is at or before step in this line coordinate\n const prevStepForTarget = getLineStep(sid, startR, startC, dr, dc);\n if (prevStepForTarget !== null && prevStepForTarget <= step &&\n tiles[sid] && tiles[sid].value === tiles[nid].value &&\n !tiles[sid].merged) {\n bestMerge = { r: sr, c: sc, targetId: sid };\n }\n break; // can't go further\n }\n\n if (!bestPos && !bestMerge) continue;\n\n if (bestMerge) {\n mergers.push({ moverId: nid, targetId: bestMerge.targetId, r: bestMerge.r, c: bestMerge.c });\n grid[cr][cc] = null;\n moved = true;\n scoreGain += tiles[nid].value;\n } else {\n // Slide to bestPos\n const finalR = bestPos ? bestPos.r : (cr);\n const finalC = bestPos ? bestPos.c : (cc);\n if (finalR !== cr || finalC !== cc) {\n // Slide through all empty cells\n for (let s = step + 1; s < SIZE; s++) {\n const sr = startR + s * dr;\n const sc = startC + s * dc;\n if (grid[sr][sc]) break;\n }\n // Move to the last empty spot before a blocker\n let destR = cr, destC = cc;\n for (let s = step + 1; s < SIZE; s++) {\n const sr = startR + s * dr;\n const sc = startC + s * dc;\n if (!grid[sr][sc]) {\n destR = sr;\n destC = sc;\n } else {\n break;\n }\n }\n if (destR !== cr || destC !== cc) {\n pushes.push({ id: nid, r: destR, c: destC });\n grid[cr][cc] = null;\n moved = true;\n }\n }\n }\n }\n }\n }\n\n // Apply all pushes (slide animations)\n for (const { id, r, c } of pushes) {\n grid[r][c] = id;\n tiles[id].r = r;\n tiles[id].c = c;\n setPos(tiles[id].el, r, c);\n }\n\n // Apply all mergers\n if (mergers.length > 0) {\n for (const { moverId, targetId, r, c } of mergers) {\n // Animate the mover sliding to the target position\n tiles[moverId].r = r;\n tiles[moverId].c = c;\n setPos(tiles[moverId].el, r, c);\n }\n\n // After animation, actually merge\n busy = true;\n setTimeout(() => {\n for (const { moverId, targetId, r, c } of mergers) {\n tiles[moverId].el.remove();\n delete tiles[moverId];\n tiles[targetId].value *= 2;\n grid[r][c] = targetId;\n tiles[targetId].r = r;\n tiles[targetId].c = c;\n updateTileVisual(targetId);\n tiles[targetId].el.classList.add('merged');\n setTimeout(() => tiles[targetId].el.classList.remove('merged'), 200);\n }\n tiles.$none = {}; // reset merged flags\n for (const key in tiles) { if (typeof key === 'number' || key.match(/^\\d+$/)) tiles[key].merged = false; }\n\n if (scoreGain > 0) addScore(scoreGain);\n\n // Spawn new tile\n spawnTile();\n\n // Check win\n if (!won && !keepPlaying) {\n checkWin();\n }\n\n // Check lose\n if (!gameOver && !hasMoves()) {\n gameOver = true;\n setTimeout(() => loseOvl.classList.add('active'), 400);\n }\n\n busy = false;\n }, 150);\n\n // Reset merged flags\n for (const key in tiles) { if (typeof key === 'number' || key.match(/^\\d+$/)) tiles[key].merged = true; }\n } else {\n // No merges — just reset flags\n if (scoreGain > 0) addScore(scoreGain);\n for (const key in tiles) { if (typeof key === 'number' || key.match(/^\\d+$/)) tiles[key].merged = false; }\n\n setTimeout(() => {\n spawnTile();\n\n if (!won && !keepPlaying) checkWin();\n if (!gameOver && !hasMoves()) { gameOver = true; setTimeout(() => loseOvl.classList.add('active'), 400); }\n }, 160);\n }\n }\n\n // Get the step (0-3) of a tile on a line starting at (startR, startC) with direction (dr, dc)\n function getLineStep(id, startR, startC, dr, dc) {\n const t = tiles[id];\n if (!t) return null;\n const drDir = dr > 0 ? 1 : dr < 0 ? -1 : 0;\n const dcDir = dc > 0 ? 1 : dc < 0 ? -1 : 0;\n\n if (dr !== 0) {\n if (t.c !== startC) return null;\n const step = (t.r - startR) / drDir;\n if (drDir === 0) return null;\n if (step >= 0 && step < SIZE && step === Math.floor(step)) return step;\n } else {\n if (t.r !== startR) return null;\n const step = (t.c - startC) / dcDir;\n if (dcDir === 0) return null;\n if (step >= 0 && step < SIZE && step === Math.floor(step)) return step;\n }\n return null;\n }\n\n // Hmm, getLineStep is fragile. Let me simplify: a tile is on the line if\n // it lies on the parametric line. The step is the distance from start in line steps.\n\n // Actually let me just redesign the whole thing once more with a much cleaner approach.\n // I'll scrap everything after this point...\n})();\n</script>\n</body>\n</html>" }
thinking
I had a bait issue with the validation but the content looks wrong - the file I was writing had deeply broken game logic with multiple abandoned approaches and undefined functions. Let me write a clean, correct implementation from scratch. The key is the slide logic.
Let me use the cleanest possible approach:
1. For each line (row or column based on direction), extract the tiles
2. Compress and merge the line
3. Map the result back, determining which tiles moved and which merged
4. Animate the movements, then clean up merged tiles
The cleanest approach I've seen is to:
- Extract each line as an array
- For each line, compute the "result" array (after removing gaps and merging)
- Map each result position to either: a tile that slid there, or null
- For merges: track which tile merges into which
Let me write this properly.
For the line processing:
- Input: [id1, null, id2, id3] e.g.
- Step 1: remove nulls → [id1, id2, id3]
- Step 2: merge → if tiles[id1].value === tiles[id2].value, merge them
For mapping back:
- We know the original positions of each tile
- We know the target positions in the line
- For each tile that moved: animate it to its new position
- For merges: slide the mover to the target, then remove the mover
Let me think about the exact data flow.
For a LEFT slide on a row:
- ids = [grid[r][0], grid[r][1], grid[r][2], grid[r][3]]
- process(ids) → result = [new0, new1, new2, null]
- positions = [{r,r,0}, {r,r,1}, {r,r,2}, {r,r,3}]
- For each i: if result[i] != ids[i]:
- If result[i] is a valid id and result[i] != ids[i] and ids[i] was a real tile: the tile at positions[i] doesn't exist anymore at this position - something else moved here
- Actually we want to figure out WHERE each tile went, not what's at each position
Better approach: track the "movement" of each tile.
Actually, the simplest approach:
1. For each tile on the line, find its target position
2. If it merges, the first of the pair stays, the second one slides to the same position and gets removed
Let me look at how the original 2048 code handles this. It uses a coordinate-based approach:
For direction (dr, dc):
- For each "starting" cell along the line (e.g., first row for up, first col for left):
- For each position along the line, starting from the far end:
- Get the tile at this position
- Find its farthest position (slide as far as possible, or merge if same value)
- Move the tile there (or merge)
The key insight: the traversal order matters. Process from far end toward near end.
Actually, let me use a much simpler approach that I know works:
```
function moveTile(tileId, r, c):
update tile position in grid and DOM
function slideDirection(dr, dc):
// Process in correct order
// For each line:
// Extract tiles in order (near to far in the direction of travel)
// Compute result
// Apply changes
results = {} // tileId -> {r, c} or {r, c, mergeWith: targetId}
for each line:
lineTiles = extractTiles(line) // tiles at actual positions on the line, in order from destination end
result = compressAndMerge(lineTiles)
// result is an array like [tileA, tileB, null, null]
// where the first element is closest to the destination edge
// Map each tile in result to its position on the line
linePositions = getLinePositions(line) // [{r, c}, ...] in same order as lineTiles
for i in range(SIZE):
if result[i]:
results[result[i].tileId] = {r: linePositions[i].r, c: linePositions[i].c, mergeWith: result[i].mergeTarget}
// Now apply all movements simultaneously
for tileId, dest in results:
moveTile(tileId, dest.r, dest.c)
// Handle merges
mergedTiles = []
for tileId, dest in results:
if dest.mergeWith:
moveTile(tileId, dest.r, dest.c) // slide to target
mergedTiles.push({mover: tileId, target: dest.mergeWith, r: dest.r, c: dest.c})
setTimeout(() => {
for merge in mergedTiles:
remove(merge.mover)
updateValue(merge.target, merge.target.value * 2 + ...)
}, 150)
```
OK let me actually just write clean code. I'll use a simple, well-tested approach.
The approach:
1. For each line (4 lines), extract the line as [value, id] pairs from "leading edge" to "trailing edge"
2. Remove gaps: [non-null pairs]
3. Merge from leading edge: if adjacent pairs have same value, merge them (combine values, mark one for removal)
4. Pad back to size 4 with nulls
5. For each position in the result line, if there's a tile, move it to that position
6. The tile that was "merged away" slides to the merged target position, then is removed
Let me code this up cleanly. I'll process the grid by extracting 4 lines, processing each, and then applying the changes.
Key detail: when extracting a line, I need the tiles in the correct order (from the destination edge). For a LEFT slide on row 0:
- ids at positions: grid[0][0], grid[0][1], grid[0][2], grid[0][3]
- The leading edge is column 0 (destination)
- Order for processing: [grid[0][0], grid[0][1], grid[0][2], grid[0][3]] (already in order)
For a RIGHT slide on row 0:
- Leading edge is column 3
- Order for processing: [grid[0][3], grid[0][2], grid[0][1], grid[0][0]]
For UP on column c:
- Leading edge is row 0
- Order: [grid[0][c], grid[1][c], grid[2][c], grid[3][c]]
For DOWN on column c:
- Leading edge is row 3
- Order: [grid[3][c], grid[2][c], grid[1][c], grid[0][c]]
After processing, I map the result back to positions.
Let me write this out:
```javascript
function slide(dr, dc) {
// dr, dc define the direction. Process 4 lines.
// For each line, collect tiles from leading edge to trailing edge.
const lines = []; // each: { tiles: [[value, id], ...], positions: [[r, c], ...] }
if (dc === -1) { // LEFT
for (let r = 0; r < 4; r++) {
const tiles = [], positions = [];
for (let c = 0; c < 4; c++) {
const id = grid[r][c];
tiles.push(id ? [tiles[id].value, id] : null);
positions.push([r, c]);
}
lines.push({ tiles, positions });
}
}
// ... similar for other directions
}
```
Hmm this is getting verbose. Let me just code the whole thing properly and write it out.
Actually, the trickiest part is that I need to know whether two adjacent tiles can merge. The rule is: each tile can only merge once per move. So if we process line left-to-right and merge tile[0] with tile[1], then tile[2] cannot merge with the merged [0,1] tile.
The standard approach: compress and then merge from the leading edge.
Let me write the full game now with all the pieces.
I think the cleanest approach for the slide is:
```javascript
function processLine(tileIds) {
// tileIds: [id1, id2, null, id3, ...] from leading edge to trailing edge
// Returns: { tiles: [{value, id, action: 'stay'/'move'/'merge-into'}], scoreGain }
// Phase 1: extract non-null tiles
const entries = tileIds.filter(id => id !== null).map(id => ({
id,
value: tiles[id].value,
merged: false
}));
// Phase 2: merge from leading edge
const merged = [];
let scoreGain = 0;
for (let i = 0; i < entries.length; i++) {
const e = entries[i];
if (merged.length > 0 && !merged[merged.length-1].done &&
e.value === merged[merged.length-1].value) {
// Merge: last entry absorbs this one
merged[merged.length-1].value *= 2;
merged[merged.length-1].done = true;
e.absorbedBy = merged[merged.length-1].id;
scoreGain += e.value * 2;
}
merged.push(e);
}
// The 'merged' array now has the result tiles and absorbed tiles
// But we need to eliminate absorbed tiles
const result = merged.filter(e => !e.absorbedBy);
// Pad to SIZE
while (result.length < SIZE) result.push(null);
// Now figure out the target position for each original tile
// Original tile that's in result: it moves to result's index on the line
// Original tile that's absorbed: it merges into its target
const moves = []; // { id, targetIndex, mergesInto: id or null }
for (let i = 0; i < entries.length; i++) {
const e = entries[i];
// Find this tile's position in result
const resultIdx = result.findIndex(r => r && r.id === e.id);
if (resultIdx >= 0) {
moves.push({ id: e.id, targetIndex: resultIdx, mergesInto: null });
} else if (e.absorbedBy) {
// This tile merges into absorbedBy
// Find absorbedBy's result position
const targetIdx = result.findIndex(r => r && r.id === e.absorbedBy);
moves.push({ id: e.id, targetIndex: targetIdx, mergesInto: e.absorbedBy });
}
}
return { moves, scoreGain, originalTileIds: tileIds };
}
```
Wait, there's a subtlety. When tile A merges into tile B, the positions need to be:
- Tile B moves to its result position (could be different from original)
- Tile A slides to B's result position too (then disappears)
Actually both need to end up at B's result position. But B's result position in the compressed array IS its position since merge handles the compression.
Let me just code the full thing now. I'll write it as a clean, self-contained file.
For the line extraction, let me parameterize:
```javascript
function getLine(r, c, dr, dc) {
// Extract a line starting from (r,c) going in direction (dr,dc)
// Actually, I want to extract from the "leading edge" (closest to destination)
// The leading edge is:
// LEFT: row, col 0; RIGHT: row, col 3
// UP: row 0, col; DOWN: row 3, col
// Direction within the leading-to-trailing order is (dr,dc)
}
```
Hmm, let me simplify. I'll process each row/col directly:
```javascript
function doMove(direction) {
// direction: 'left', 'right', 'up', 'down'
let moved = false;
let totalScore = 0;
const allMoves = []; // { id, r, c } - where each tile should go
const allMerges = []; // { moverId, targetId, r, c } - merges that happen
if (direction === 'left') {
for (let r = 0; r < 4; r++) {
const tokens = [];
for (let c = 0; c < 4; c++) {
const id = grid[r][c];
if (id) tokens.push({ id, value: tiles[id].value });
}
// Merge from left
let scoreGain = 0;
for (let i = 0; i < tokens.length - 1; i++) {
if (tokens[i].value === tokens[i+1].value) {
tokens[i].value *= 2;
tokens[i].merged = true; // mark the second for removal
tokens.splice(i+1, 1);
scoreGain += tokens[i].value / 2 * 2; // original value * 2... wait
scoreGain += tokens[i].value;
// Wait that's wrong. If tokens[i].value was 2 and tokens[i+1].value was 2,
// after merge tokens[i].value = 4, scoreGain should be 4.
// But the ORIGINAL value is tokens[i].value / 2 = 2.
// Actually scoreGain += tokens[i].value / 2 * 2 = tokens[i].value / 2 = 2? No.
// The score gained from merging two 2s is 4.
// Before merge, tokens[i].value = 2, tokens[i+1].value = 2
// After merge, tokens[i].value = 4
// Score gain = 4
// So scoreGain += tokens[i].value (after merge, which is 4) is correct!
i++; // skip next
}
}
totalScore += scoreGain;
// Map tokens back to grid positions
let ci = 0;
for (const token of tokens) {
if (ci < 4) {
allMoves.push({ id: token.id, r: r, c: ci });
ci++;
}
}
// Find merge pairs
// ... this is getting complicated because I need to know which original tile
// was merged into which
// Actually I need to track which tiles merge
// Let me redo this...
}
}
}
```
OK I think the fundamental issue is tracking merge pairs. Let me use a different approach: instead of modifying the array in place with splicing, I'll use the entry-tracking approach.
```javascript
function processLine(tokens) {
// tokens: [{ id, value }, ...] from leading edge to trailing edge
// After merge processing, we get:
// - For each original token, where it ends up
// - For tokens that are merged-away, where they slide to before removal
const entries = tokens.map(t => ({ ...t, absorbedBy: null }));
const result = []; // non-absorbed entries in order
for (let i = 0; i < entries.length; i++) {
if (result.length > 0 &&
entries[i].value === result[result.length - 1].value &&
!result[result.length - 1].absorbed &&
!entries[i].absorbedBy) {
// Merge: result[last] absorbs entries[i]
result[result.length - 1].value *= 2;
result[result.length - 1].absorbed = true;
entries[i].absorbedBy = result[result.length - 1].id;
}
result.push(entries[i]);
// Don't add absorbed entries to result list
if (entries[i].absorbedBy) result.pop();
}
// Now result has the final tiles (with updated values)
// Pad to 4
while (result.length < 4) result.push(null);
// Moves: for each original token, compute its destination
const moves = [];
for (let i = 0; i < entries.length; i++) {
const e = entries[i];
const targetIdx = result.findIndex(r => r && r.id === e.id);
if (targetIdx >= 0) {
moves.push({ id: e.id, targetIndex: targetIdx });
} else if (e.absorbedBy) {
const targetIdx = result.findIndex(r => r && r.id === e.absorbedBy);
moves.push({ id: e.id, targetIndex: targetIdx, absordsInto: e.absorbedBy });
}
}
return { moves, result };
}
```
Now for each line, I can get the moves and know exactly where each tile goes and what merges happen.
Let me now write the complete game file. The HTML/CSS is straightforward, the JS is the main challenge. Let me write it all cleanly.
For the direction approach:
```
LEFT: for each row r, extract grid[r][0..3], process, assign to grid[r][0..n]
RIGHT: for each row r, extract grid[r][3..0], process, assign to grid[r][3-n..3]
UP: for each col c, extract grid[0..3][c], process, assign to grid[0..n][c]
DOWN: for each col c, extract grid[3..0][c], process, assign to grid[3-n..3][c]
```
For RIGHT and DOWN, the extraction order is REVERSED (from the leading edge).
Actually wait. When processing, I extract from the LEADING edge (the edge the tiles move toward). So:
- LEFT: leading edge is col 0, extract [grid[r][0], grid[r][1], grid[r][2], grid[r][3]]
- RIGHT: leading edge is col 3, extract [grid[r][3], grid[r][2], grid[r][1], grid[r][0]]
- UP: leading edge is row 0, extract [grid[0][c], grid[1][c], grid[2][c], grid[3][c]]
- DOWN: leading edge is row 3, extract [grid[3][c], grid[2][c], grid[1][c], grid[0][c]]
The processLine function takes these tokens and produces moves where:
- targetIndex 0 is the leading edge position
- targetIndex 1 is the next position, etc.
Then I map target indices back to grid positions.
For LEFT row r: targetIndex i → grid[r][i]
For RIGHT row r: targetIndex i → grid[r][3-i]
For UP col c: targetIndex i → grid[i][c]
For DOWN col c: targetIndex i → grid[3-i][c]
This should work cleanly!
Now let me write the whole thing. I'll put all CSS in a <style> tag and all JS in a <script> tag.
Here's my complete plan for the game:
1. State:
- grid: 4x4 array of tile IDs or null
- tiles: map of tile ID → { el, value, r, c }
- score, best, won, keepPlaying, gameOver, busy
2. initGame():
- Clear grid, tiles, score
- Spawn 2 random tiles
3. spawnTile():
- Find empty cell, create tile with value 2 (90%) or 4 (10%)
- Animate with 'new' class
4. slide(dr, dc):
- Extract 4 lines based on direction
- Process each line (compress + merge)
- Collect all moves and merges
- Animate tile movements
- After 150ms, handle merges (remove absorbed tiles, update values)
- Spawn new tile
- Check win/lose
5. Keyboard handler for arrow keys
6. Touch handler for mobile
7. Win overlay with "Keep Going" option
Let me write it!
Let me write a clean, correct implementation from scratch:
/workspace/index.html (16896 bytes)Successfully wrote 16896 bytes to /workspace/index.html
TAKE IT TO CODE
This run produced no artifact — reuse the prompt with a different model or your own pi-agent run.