Conway's Game of Life · mercury-3
Output generated Cost / run $0.0155 Runtime 85.6s
Prompt for this run
Build Conway's Game of Life on a canvas with a 60 by 40 grid and finite, non-wrapping boundaries. Use HTML, CSS, and JavaScript as needed. Write it to `index.html` in the current working directory using your file tools. Inline your own CSS and JavaScript. Do not use external assets, CDNs, or network requests. No third-party libraries are provided. Required behavior: - Apply the standard rules simultaneously: a live cell survives with two or three live neighbors, and a dead cell becomes live with exactly three. Treat cells outside the grid as dead. - Start paused with a visible blinker pattern. Provide Play/Pause, Step, Randomize, and Clear, plus a generation counter. - While paused, clicking toggles a cell. On a drag, choose painting alive or dead from the first cell and apply that same state to each visited cell, without repeatedly toggling it. - Step advances exactly one generation while paused. Randomize and Clear leave the simulation paused and reset the generation counter; Clear removes all live cells. - Fit the grid and controls within the viewport while keeping cells distinguishable. Verify: Step the initial blinker twice and compare its alternating arrangements. Paint a short stroke while paused and check consistent cell painting, then use Clear and confirm the grid and generation counter reset.
TAKE IT TO CODE
A single self-contained HTML file — copy it and open in any browser, or reuse the prompt with your own pi-agent run.
RUN
METRICS
Transcript · 53 messages
Build Conway's Game of Life on a canvas with a 60 by 40 grid and finite, non-wrapping boundaries. Use HTML, CSS, and JavaScript as needed. Write it to `index.html` in the current working directory using your file tools. Inline your own CSS and JavaScript. Do not use external assets, CDNs, or network requests. No third-party libraries are provided. Required behavior: - Apply the standard rules simultaneously: a live cell survives with two or three live neighbors, and a dead cell becomes live with exactly three. Treat cells outside the grid as dead. - Start paused with a visible blinker pattern. Provide Play/Pause, Step, Randomize, and Clear, plus a generation counter. - While paused, clicking toggles a cell. On a drag, choose painting alive or dead from the first cell and apply that same state to each visited cell, without repeatedly toggling it. - Step advances exactly one generation while paused. Randomize and Clear leave the simulation paused and reset the generation counter; Clear removes all live cells. - Fit the grid and controls within the viewport while keeping cells distinguishable. Verify: Step the initial blinker twice and compare its alternating arrangements. Paint a short stroke while paused and check consistent cell painting, then use Clear and confirm the grid and generation counter reset.
I'll build the Game of Life as a single self-contained `index.html`. Let me start by writing the file.
index.html (9748 bytes)Successfully wrote to index.html
Now let me verify in the browser:
{"action":"reload"}{"console":[],"dom":"GAME OF LIFE\nPlay\nStep\nRandomize\nClear\nGeneration: 0\nPaused","images":"model does not support images"}
{"command":"cd /tmp/job-Ntfq0E && ls -la && node -v 2>&1; which chromium chromium-browser google-chrome google-chrome-stable 2>/dev/null; lstotal 24 drwx------ 3 node node 4096 Oct 23 09:53 . drwxrwxrwt 10 root root 4096 Oct 23 09:54 .. drwxr-xr-x 4 node node 4096 Oct 23 09:53 .home -rw-r--r-- 1 node node 9748 Oct 23 09:53 index.html v24.18.0 @cloudflare @earendil-works @sinclair entities parse5 playwright playwright-core yaml
{"command":"ls /app/pipeline/node_modules/playwright-core 2>/dev/null | head; ls ~/.cache/ms-playwright 2>/dev/null; find / -maxdepth 6 -namLICENSE NOTICE README.md ThirdPartyNotices.txt bin browsers.json cli.js index.d.ts index.js index.mjs
{"command":"find / -maxdepth 8 \\( -name 'chrome' -o -name 'chromium' -o -name 'headless_shell' -o -name 'chrome-headless-shell' \\) -type f/opt/playwright/chromium_headless_shell-1234/chrome-headless-shell-linux64/chrome-headless-shell /opt/playwright/chromium-1234/chrome-linux64/chrome --- --- /usr/local/lib +-- corepack@0.35.0 `-- npm@11.16.0
{"command":"cd /tmp/job-Ntfq0E && cat > test.mjs <<'EOF'\nimport { chromium } from '/app/pipeline/node_modules/playwright/index.mjs';\n\nconinitial {"generation":0,"running":false,"live":3,"coords":[[29,20],[30,20],[31,20]]} after step1 {"generation":1,"running":false,"live":3,"coords":[[30,19],[30,20],[30,21]]} after step2 {"generation":2,"running":false,"live":3,"coords":[[29,20],[30,20],[31,20]]} step2 == initial: true after clear {"generation":0,"running":false,"live":0,"coords":[]} canvas box {"x":90,"y":87,"width":1020,"height":680} after drag stroke {"generation":0,"running":false,"live":26,"coords":[[3,7],[4,7],[5,7],[6,7],[7,7],[8,7],[9,7],[10,7],[11,7],[12,7],[13,7],[14,7],[15,7],[16,7],[17,7],[18,7],[19,7],[20,7],[20,8],[20,9],[20,10],[20,11],[20,12],[20,13],[20,14],[20,15]]} stroke path cells checked: 26 dead on path: 0 live outside stroke path: 0 after click toggle (should remove (10,7)) {"generation":0,"running":false,"live":26,"coords":[[3,7],[4,7],[5,7],[6,7],[7,7],[8,7],[9,7],[10,7],[11,7],[12,7],[13,7],[14,7],[15,7],[16,7],[17,7],[18,7],[19,7],[20,7],[20,8],[20,9],[20,10],[20,11],[20,12],[20,13],[20,14],[20,15]]} after clear: gen= 0 running= false live= 0 after randomize: gen= 0 running= false live= 556 console errors: none
Found a real bug: I bound both `pointer` and `mouse` handlers to the canvas, so one press fires `beginPaint` twice, flipping the paint value and making plain clicks a no-op. Let me fix that.
{"path":"index.html","edits":[{"oldText":" canvas.addEventListener(\"pointerdown\", beginPaint);\n canvas.addEventListener(\"pointermove\"Successfully replaced 1 block(s) in index.html.
{"command":"cd /tmp/job-Ntfq0E && node test.mjs"}initial {"generation":0,"running":false,"live":3,"coords":[[29,20],[30,20],[31,20]]} after step1 {"generation":1,"running":false,"live":3,"coords":[[30,19],[30,20],[30,21]]} after step2 {"generation":2,"running":false,"live":3,"coords":[[29,20],[30,20],[31,20]]} step2 == initial: true after clear {"generation":0,"running":false,"live":0,"coords":[]} canvas box {"x":90,"y":87,"width":1020,"height":680} after drag stroke {"generation":0,"running":false,"live":26,"coords":[[3,7],[4,7],[5,7],[6,7],[7,7],[8,7],[9,7],[10,7],[11,7],[12,7],[13,7],[14,7],[15,7],[16,7],[17,7],[18,7],[19,7],[20,7],[20,8],[20,9],[20,10],[20,11],[20,12],[20,13],[20,14],[20,15]]} stroke path cells checked: 26 dead on path: 0 live outside stroke path: 0 after click toggle (should remove (10,7)) {"generation":0,"running":false,"live":26,"coords":[[3,7],[4,7],[5,7],[6,7],[7,7],[8,7],[9,7],[10,7],[11,7],[12,7],[13,7],[14,7],[15,7],[16,7],[17,7],[18,7],[19,7],[20,7],[20,8],[20,9],[20,10],[20,11],[20,12],[20,13],[20,14],[20,15]]} after clear: gen= 0 running= false live= 0 after randomize: gen= 0 running= false live= 613 console errors: none
{"command":"cd /tmp/job-Ntfq0E && cat > probe.mjs <<'EOF'\nimport { chromium } from '/app/pipeline/node_modules/playwright/index.mjs';\nconsKLICK events: EV pointermove EV mousemove EV pointerdown EV mousedown EV pointerup EV mouseup
{"command":"cd /tmp/job-Ntfq0E && cat > probe2.mjs <<'EOF'\nimport { chromium } from '/app/pipeline/node_modules/playwright/index.mjs';\nconbefore: [[29,20],[30,20],[31,20]] after click (5,5): [[29,20],[30,20],[31,20]] after click (30,20): [[29,20],[30,20],[31,20]]
{"command":"cd /tmp/job-Ntfq0E && cat > probe3.mjs <<'EOF'\nimport { chromium } from '/app/pipeline/node_modules/playwright/index.mjs';\nconPROBE down cell=5,5 PROBE click event fired
{"command":"cd /tmp/job-Ntfq0E && cat > probe4.mjs <<'EOF'\nimport { chromium } from '/app/pipeline/node_modules/playwright/index.mjs';\nconcells: 3
{"command":"cd /tmp/job-Ntfq0E && sed -n '200,320p' index.html"}var dpr = window.devicePixelRatio || 1; canvas.width = Math.round(COLS * cellPx * dpr); canvas.height = Math.round(ROWS * cellPx * dpr); canvas.style.width = (COLS * cellPx) + "px"; canvas.style.height = (ROWS * cellPx) + "px"; ctx.setTransform(dpr, 0, 0, dpr, 0, 0); ctx.scale(cellPx, cellPx); draw(); } function draw() { var c, r; // background ctx.fillStyle = "#0a0e15"; ctx.fillRect(0, 0, COLS, ROWS); // live cells ctx.fillStyle = "#38bdf8"; var inset = 0.07; for (r = 0; r < ROWS; r++) { for (c = 0; c < COLS; c++) { if (cells[r * COLS + c]) { ctx.fillRect(c + inset, r + inset, 1 - inset * 2, 1 - inset * 2); } } } // grid lines ctx.strokeStyle = "rgba(159, 183, 212, 0.07)"; ctx.lineWidth = 1 / cellPx; ctx.beginPath(); for (c = 1; c < COLS; c++) { ctx.moveTo(c + 0.5, 0); ctx.lineTo(c + 0.5, ROWS); } for (r = 1; r < ROWS; r++) { ctx.moveTo(0, r + 0.5); ctx.lineTo(COLS, r + 0.5); } ctx.stroke(); // border ctx.strokeStyle = "rgba(125, 211, 252, 0.25)"; ctx.lineWidth = 2 / cellPx; ctx.strokeRect(1 / cellPx, 1 / cellPx, COLS - 2 / cellPx, ROWS - 2 / cellPx); } // ---- interaction ---- var painting = false; var paintValue = 0; var lastPainted = null; function eventCell(e) { var rect = canvas.getBoundingClientRect(); var x = e.clientX - rect.left; var y = e.clientY - rect.top; var c = Math.floor(x / cellPx); var r = Math.floor(y / cellPx); if (c < 0 || c >= COLS || r < 0 || r >= ROWS) return null; return { c: c, r: r, i: r * COLS + c }; } function paintLine(a, b) { if (!a) { cells[b.i] = paintValue; lastPainted = b; return; } var dc = b.c - a.c; var dr = b.r - a.r; var steps = Math.max(Math.abs(dc), Math.abs(dr)); for (var t = 0; t <= steps; t++) { var c = Math.round(a.c + dc * t / steps); var r = Math.round(a.r + dr * t / steps); cells[r * COLS + c] = paintValue; } lastPainted = b; } function beginPaint(e) { if (running) return; var cell = eventCell(e); if (!cell) return; painting = true; // painting state derived from the first cell (opposite of its current state) paintValue = cells[cell.i] ? 0 : 1; lastPainted = null; paintLine(cell, cell); draw(); if (canvas.setPointerCapture && e.pointerId !== undefined) { try { canvas.setPointerCapture(e.pointerId); } catch (err) {} } } function continuePaint(e) { if (!painting) return; var cell = eventCell(e); if (!cell) return; paintLine(lastPainted, cell); draw(); } function endPaint() { painting = false; lastPainted = null; } canvas.addEventListener("pointerdown", beginPaint); canvas.addEventListener("pointermove", continuePaint); canvas.addEventListener("pointerup", endPaint); canvas.addEventListener("pointercancel", endPaint); // ---- controls ---- btnPlay.addEventListener("click", function () { setPaused(running); }); btnStep.addEventListener("click", function () { if (running) return; step(); });
{"path":"index.html","edits":[{"oldText":" function beginPaint(e) {\n if (running) return;\n var cell = eventCell(e);\n if (!cell)Successfully replaced 1 block(s) in index.html.
{"command":"cd /tmp/job-Ntfq0E && node probe4.mjs"}cells: 3 CONSOLE DEBUG beginPaint 5 5 pv 1 CONSOLE DEBUG beginPaint 5 5 pv 1
{"command":"cd /tmp/job-Ntfq0E && cat > probe5.mjs <<'EOF'\nimport { chromium } from '/app/pipeline/node_modules/playwright/index.mjs';\ncon{"beforeRead":0,"liveCount":3} after wait: {"live":3} CONSOLE DEBUG beginPaint 5 5 pv 1
{"path":"index.html","edits":[{"oldText":" function paintLine(a, b) {\n if (!a) {\n cells[b.i] = paintValue;\n lastPainted = bSuccessfully replaced 1 block(s) in index.html.
{"command":"cd /tmp/job-Ntfq0E && node probe5.mjs"}{"beforeRead":0,"liveCount":3} after wait: {"live":3} CONSOLE DEBUG paintLine a= 305 b= 305 pv= 1 cur= 0 CONSOLE DEBUG beginPaint 5 5 pv 1
{"path":"index.html","edits":[{"oldText":" var steps = Math.max(Math.abs(dc), Math.abs(dr));\n for (var t = 0; t <= steps; t++) {\n Successfully replaced 1 block(s) in index.html.
{"command":"cd /tmp/job-Ntfq0E && node probe5.mjs"}{"beforeRead":0,"liveCount":3} after wait: {"live":3} CONSOLE DEBUG paintLine a= 305 b= 305 pv= 1 cur= 0 CONSOLE DEBUG loop set NaN -> undefined CONSOLE DEBUG beginPaint 5 5 pv 1
{"path":"index.html","edits":[{"oldText":" function paintLine(a, b) {\n console.log('DEBUG paintLine a=', a && a.i, 'b=', b.i, 'pv=', paSuccessfully replaced 2 block(s) in index.html.
{"command":"cd /tmp/job-Ntfq0E && node test.mjs"}initial {"generation":0,"running":false,"live":3,"coords":[[29,20],[30,20],[31,20]]} after step1 {"generation":1,"running":false,"live":3,"coords":[[30,19],[30,20],[30,21]]} after step2 {"generation":2,"running":false,"live":3,"coords":[[29,20],[30,20],[31,20]]} step2 == initial: true after clear {"generation":0,"running":false,"live":0,"coords":[]} canvas box {"x":90,"y":87,"width":1020,"height":680} after drag stroke {"generation":0,"running":false,"live":26,"coords":[[3,7],[4,7],[5,7],[6,7],[7,7],[8,7],[9,7],[10,7],[11,7],[12,7],[13,7],[14,7],[15,7],[16,7],[17,7],[18,7],[19,7],[20,7],[20,8],[20,9],[20,10],[20,11],[20,12],[20,13],[20,14],[20,15]]} stroke path cells checked: 26 dead on path: 0 live outside stroke path: 0 after click toggle (should remove (10,7)) {"generation":0,"running":false,"live":25,"coords":[[3,7],[4,7],[5,7],[6,7],[7,7],[8,7],[9,7],[11,7],[12,7],[13,7],[14,7],[15,7],[16,7],[17,7],[18,7],[19,7],[20,7],[20,8],[20,9],[20,10],[20,11],[20,12],[20,13],[20,14],[20,15]]} after clear: gen= 0 running= false live= 0 after randomize: gen= 0 running= false live= 600 console errors: none
{"command":"cd /tmp/job-Ntfq0E && cat > test2.mjs <<'EOF'\nimport { chromium } from '/app/pipeline/node_modules/playwright/index.mjs';\nconsstart: {"gen":0,"running":false} randomized: {"gen":0,"running":false} playing: {"gen":5,"running":true} paused: {"gen":5,"running":false} after pause wait gen unchanged: true running= false small viewport {"w":800,"h":600} canvas {"x":40,"y":87,"width":720,"height":480} canvas fits: true cell distinguishable (>=5px): true
{"command":"cd /tmp/job-Ntfq0E && rm -f test.mjs test2.mjs probe.mjs probe2.mjs probe3.mjs probe4.mjs probe5.mjs && ls -la"}total 24 drwx------ 3 node node 4096 Oct 23 09:55 . drwxrwxrwt 10 root root 4096 Oct 23 09:55 .. drwxr-xr-x 7 node node 4096 Oct 23 09:54 .home -rw-r--r-- 1 node node 9607 Oct 23 09:54 index.html
{"action":"reload"}{"console":[],"dom":"GAME OF LIFE\nPlay\nStep\nRandomize\nClear\nGeneration: 0\nPaused","images":"model does not support images"}
Done. `index.html` is built and verified in the current directory. **Implementation summary** - 60×40 canvas grid with finite boundaries (cells outside treated as dead, standard simultaneous update rules). - Starts paused with a horizontal blinker at center, generation counter at 0. - Controls: Play/Pause, Step, Randomize, Clear, plus generation counter and status label. - Paused interactions: click toggles a cell; drag derives the paint state (live/dead) from the first cell, clamps it, and applies that same state to every visited cell along the stroke (line-interpolated, so no gaps and no repeated toggling). - Randomize/Clear force-pause and reset the generation counter; Clear empties the grid. - Responsive canvas sizing keeps the grid + controls inside the viewport with distinguishable cells. **What I actually checked (via headless Chromium/Playwright against the live page)** - Initial state: paused, generation 0, live cells exactly `(29,20),(30,20),(31,20)`. - Step 1 → vertical blinker `(30,19),(30,20),(30,21)`; Step 2 → horizontal again, byte-identical to initial, generation incremented each time. - Drag stroke from a dead cell: all 26 visited path cells painted alive, zero live cells outside the stroke; then clicking a painted cell toggled it off (verifying click toggle). - Clear → grid empty, generation 0, paused. Randomize → paused, generation 0, populated. - Play ran (generation advanced 0→5 in ~0.6s) and Pause froze it; console error-free. - Viewport fit at 1200×800 and 800×600 (canvas 1020×680 / 720×480, cells ≥5px). **Unverified/remaining** - Visual styling appearance (couldn't view screenshots in this session — geometry, DOM text, and state were verified instead). - Interactions at extreme desktop sizes (e.g., very wide/tall windows) and touch/pen pointer input specifically; the same pointer-event code path is used for both.