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v0 source realm

Package pixelcanvas is a shared 16x16 pixel canvas: anyone can paint one cell at a time from a fixed 9-colour palette...

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Pixel Canvas

⚠️ Experimental — generated with no human supervision by the daily MCP pipeline to exercise gno tooling. Not audited. See r/moul/x/daily.

A shared 16x16 canvas. Anyone can paint one cell at a time from a fixed 9-colour palette, and the board renders in gnoweb as a grid of coloured blocks.

Painting is last-write-wins — that's the point of a shared canvas. Both strokes still count toward the painter tallies, so overwriting someone doesn't erase their contribution from the leaderboard.

Paint(x, y, colour)   → colours a cell, returns the total stroke count
At(x, y)              → the colour name of a cell ("white" when untouched)
PainterAt(x, y)       → who last painted it ("" when untouched)
Strokes()             → total paints ever
Palette()             → the accepted colour names

/r/moul/x/daily/pixelcanvas/v0        → the canvas, palette and top painters
/r/moul/x/daily/pixelcanvas/v0:4,9    → who painted that cell, and what colour

Coordinates are 0-based with (0,0) at the top-left, and are x (column) then y (row) — so (3,7) is column 3 of row 7. Colour names are matched case- and space-insensitively.

Palette: white, red, orange, yellow, green, blue, purple, brown, black.

The grid is a fixed [Size*Size]int of palette indices rather than a tree: every cell exists from the start and the whole grid is walked on each render, so an array is both simpler and cheaper than a sparse structure.

Only an EOA can paint (IsUserCall), so another realm can't spray the canvas on a user's behalf.

Built for gno 0.9. Live on both testnets (agent address):

  • sapphire — https://sapphire.testnets.gno.land/r/g12cs4cehujpffpjpywmkqj43m6u5ya53nj69sjz/pixelcanvas
  • pearl — https://pearl.testnets.gno.land/r/g12cs4cehujpffpjpywmkqj43m6u5ya53nj69sjz/pixelcanvas

Part of moul/gno-contracts — moul's versioned gno.land contracts. See the repository for the full catalog, build/test tooling, and usage.

Dependency graph:

gno.land/r/moul/x/daily/pixelcanvas/v0 dependency graph

🧪 Highly experimental — potentially vibe-coded. Not audited; may break, change, or be removed at any time. Do not use with anything of value. Full disclaimer: DISCLAIMER.

Overview

Package pixelcanvas is a shared 16x16 pixel canvas: anyone can paint one cell at a time from a fixed 9-colour palette, and the canvas renders in gnoweb as a grid of coloured blocks.

The canvas is a flat [Size*Size]int of palette indices held in realm state — a fixed-size array rather than a tree, because every cell exists from the start and the grid is walked in full on every render. Painting is last-write-wins; the realm keeps who painted each cell and a per-address tally, so the board doubles as a contribution leaderboard.

A stateful app with nothing reusable to extract, so it ships as a lone realm rather than a p/ library + demo pair.

Constants 1

const Size 

1const Size = 16
source

Size is the canvas edge length; the canvas is Size x Size cells.

Functions 6

func At

Action 
1func At(x, y int) string
source

At returns the palette name of the cell at (x, y), or "" when out of bounds.

func Paint

crossing Action 
1func Paint(cur realm, x, y int, colour string) int
source

Paint colours the cell at (x, y) and returns the total number of strokes.

Coordinates are 0-based with (0,0) at the top-left. Colour is a palette name ("red", "blue", …) — see Palette. Painting over an existing cell is allowed: the canvas is last-write-wins, which is the whole point of a shared board.

func PainterAt

Action 
1func PainterAt(x, y int) string
source

PainterAt returns the address that last painted (x, y), or "" if untouched.

func Palette

Action 
1func Palette() string
source

Palette returns the accepted colour names, comma-separated.

func Render 

1func Render(path string) string
source

Render renders the canvas for gnoweb.

Example
1Render("")        / Render("/") -> the canvas, palette and leaderboard
2Render("/<x>,<y>")              -> who painted that cell, and what colour

Imports 6

Source Files 3