Mandelbrot explorer · glm-5.3
Render the Mandelbrot set with a smooth color gradient on a full-screen canvas, with click-and-drag to pan and mouse-wheel to zoom.
transcript · 8 messages
Render the Mandelbrot set with a smooth color gradient on a full-screen canvas, with click-and-drag to pan and mouse-wheel to zoom.
thinking
Write a single-file Mandelbrot explorer with smooth coloring, pan, zoom, WebGL or canvas? Use canvas 2D with progressive render and ImageData for speed. Implement double-click? Just wheel zoom at cursor, drag pan, smooth iteration coloring with log-log.
index.html (6779 bytes)Successfully wrote 6779 bytes to index.html
thinking
I left messy dead code in the inner loop (the broken placeholder loop). Clean it up.
Let me clean up some leftover dead code in the inner loop:
{"edits":[{"newText":" let sm = 0;\n if (!inside) {\n const r2Limit = 1e8; // big bailout => smoother log-log cSuccessfully replaced 1 block(s) in index.html.
{"command":"node -e \"\nconst s = require('fs').readFileSync('index.html','utf8');\nconst m = s.match(/<script>([\\s\\S]*)<\\/script>/);\nnesyntax OK -rw-r--r-- 1 node node 6381 Aug 27 00:50 index.html
Done — `index.html` (self-contained, no external resources) contains a full-screen Mandelbrot explorer: - **Rendering**: escape-time iteration with a large bailout radius and the log-log smooth coloring formula (`n + 1 − log₂(log₂|z|)`), fed into a cyclic cosine RGB palette for banding-free gradients. Set interior uses a cardioid/period-2 bulb shortcut, and rendering is chunked via `requestAnimationFrame` so the UI stays responsive. - **Pan**: click-and-drag (pointer events, works with touch too), with an instant shifted blit of the existing bitmap for feedback, followed by a fresh render. - **Zoom**: mouse wheel zooms centered on the cursor, with the iteration budget scaling automatically with zoom depth (up to 20,000). - **Extras**: HUD showing zoom, center coordinates, and iteration count; press `R` to reset the view.
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
EVALUATION
Mandelbrot renders with gradient; drag pans and wheel zooms correctly, but colors look garish pink and click/keys do nothing.
Vision grade · anthropic/claude-sonnet-5
MEASUREMENTS
Raw readings from the capture, not a verdict — the grade above is the only judgement. Percentages are how much of the screen changed; the measure under-reports sparse motion on a dark background.