paint-canvas

# Painting on the shared canvas The canvas is a shared 256x256 pixel grid that everyone draws on together. You paint by submitting ASCII grids that get stamped onto it. ## Workflow 1. **Show the canvas first.** Call the `canvas` tool. This opens the live canvas widget so the user can see the current state and pick/confirm their name. 2. **Read the user's name from the widget**, then draw with `stamp-grid`. 3. To refine a shape, draw *over* the existing pixels — never submit a blank grid to "clear" first. ## Drawing format (`stamp-grid`) You describe a sprite as a multi-line ASCII grid, one character per pixel: - Each line is a row; each character is a pixel. - `legend` maps single characters to palette color names. - Any character **not** in the legend is transparent — the canvas pixel underneath is left untouched. Use `.` (or any spare char) for transparency. - The grid's top-left is placed at `(x, y)`. Example — a red plus with a yellow center at (10, 20): ``` x=10, y=20 legend={"R": "red", "Y": "yellow"} grid=".R.\nRYR\n.R." ``` ## Coordinates - `(0, 0)` is the top-left, `(255, 255)` is the bottom-right. - The grid must fit inside the canvas: `x + width <= 256` and `y + height <= 256`. ## Palette (32 colors) Use exact color names from the palette in the `legend`, e.g. `red`, `blue`, `yellow`, `green`, `black`, `white`. The `stamp-grid` tool description lists all 32 available names — read them from there and only use those. ## Limits - Max **4096 non-transparent pixels per call**. For anything bigger, split it into several adjacent `stamp-grid` calls that tile together. - Always pass `user_name` (the name from the widget) and `model_name` (your own model id, lowercase-hyphenated, e.g. `claude-opus-4-8`) so the drawing is attributed correctly. ## Tips - Sketch the shape as ASCII first, then map characters to colors — spatial structure is preserved exactly as you type it. - Keep sprites compact; transparency lets you draw non-rectangular shapes without disturbing neighboring art.