Pixel Grid Draw Agent Skill

pixel-grid-draw

The pixel-grid MCP server exposes a linear write primitive:

write(offset: int, bits: str)

where offset ∈ [0, 1024) and bits is a string of '0' (white), '1'

(black), or '.' (skip, leave cell unchanged). The grid is 32×32,

row-major: offset = y * 32 + x.

Drawing 2D shapes in terms of write is mechanical but tedious: row

offsets must be computed, and cells that should remain untouched need

. in the right places. This skill does the mechanical part so you

can focus on the shape.

How to use

• Decide the 2D operation (rect / frame / bitmap) and its position.
• Run scripts/plan.py with those args. It emits JSON of the form:

   { "ops": [ { "offset": <int>, "bits": "<string>" }, ... ] }

• For each op in the list, call the pixel-grid write MCP tool with

those exact args.

Each command emits one op per row of the shape. This is

deliberate: packing a multi-row shape into a single long bits

string requires 2D-through-1D padding (. runs spanning the cells

between row ends and the next row's start), which balloons a dense

shape into a highly repetitive multi-kilobyte string — exactly the

input an LLM is most likely to miscopy. Per-row keeps every bits

value at most 64 chars with a distinct offset, and the ops are

independent so you can fire them in parallel.

The script never touches the network; it's a pure translator. You are

still the one making the MCP call, which means the write is visible

in the tool-call trace.

Commands

Filled rectangle

scripts/plan.py rect X Y W H

Fills a W × H block with black starting at (X, Y). Any previous

content underneath is overwritten (cells set to 1).

Outlined frame

scripts/plan.py frame X Y W H

1-pixel outline of a W × H rectangle at (X, Y). Interior cells use

. (skip), so the frame draws *around* existing content without

clobbering it.

Arbitrary bitmap

scripts/plan.py bitmap X Y

Reads the bitmap from stdin: one row per line, each character 0

(white), 1 (black), or . (skip). Top-left of the bitmap is placed

at (X, Y).

Example — a 5×4 hollow oval at (10, 10):

printf '01110\n10001\n10001\n01110\n' | \

scripts/plan.py bitmap 10 10

Clipping

Coordinates and dimensions may fall outside the grid; the plan is

clipped to 0..63 on both axes. Rows/columns that fall off the edge

are dropped silently. No op references pixels outside the grid.

Example session

User asks: *"Draw a 10×10 square at position (5, 5) and put a frame

around it at (3, 3)."*

• python3 scripts/plan.py rect 5 5 10 10 → 10 ops (one per row).
• python3 scripts/plan.py frame 3 3 14 14 → 14 ops. Middle rows

use . for the interior cells so the frame draws cleanly around

the rectangle without erasing any part of it.

• Call write(offset, bits) on the pixel-grid MCP server for each

op. The 24 calls are independent; fire them in parallel.

Notes

• If you want a blank canvas first, call the pixel-grid clear tool.
• For very small shapes, it may be quicker to compose the bits

string yourself and call write directly. Use this skill when the

shape spans multiple rows or when an ASCII-art bitmap is more

natural than hand-computed offsets.