Shape ops

For anything beyond a few cells, the cell grid gets unwieldy. Shape ops let you describe a sprite as composable shapes — much friendlier for humans and LLMs.

A sprite body is either a cell grid or a sequence of ops, not both. Ops paint in order onto a transparent base; later ops overwrite earlier ones. Out-of-bounds coordinates are silently clipped.

fill V

Fill the whole sprite with one value.

sprite bg 16x16 { fill #2a6dba }

rect X,Y X,Y V

Filled rectangle, inclusive of both corners.

sprite plank 32x4 {
  fill #7a4220
  rect 0,0 31,0 #4a2812   // shadow top edge
  rect 0,3 31,3 #4a2812   // shadow bottom edge
}

pixel X,Y V

A single pixel — used for highlights, eyes, accents.

sprite eyes 16x4 {
  fill .
  pixel 4,1 #000
  pixel 11,1 #000
}

line X,Y X,Y V

Bresenham line, 1 pixel thick. Works at any angle.

sprite cross 16x16 {
  fill .
  line 0,0 15,15 #fff
  line 15,0 0,15 #fff
}

circle CX,CY R V

Filled disc.

sprite sun 32x32 {
  fill #87ceeb
  circle 16,16 8 #ffd700
}

flip h / flip v

Reflect the entire canvas in place, at the point the op runs. flip h mirrors left↔right (x → W-1-x); flip v mirrors top↔bottom (y → H-1-y). The axis must be h or v.

Because it reflects everything drawn so far, flip is for re-orienting a finished sprite — not for building symmetry. Drawing one half and flip h moves that half to the other side and leaves the original side blank. For a symmetric sprite, draw both sides instead (centered circle/rect shapes are already symmetric).

sprite arrow 8x8 {
  fill .
  line 1,4 6,4 #fff   // shaft
  line 3,1 6,4 #fff   // upper barb
  line 3,7 6,4 #fff   // lower barb — arrow pointing right
  flip h              // whole canvas mirrored → now points left
}

Transparency

The canvas starts fully transparent and the PNG is written as RGBA, so anything you don't paint stays see-through. Three ways to work with it:

• Leave it unpainted. In ops mode the base is already clear, so fill . is optional — it's just an explicit way to say "transparent background." Paint your shapes and the surrounding pixels stay transparent.

• . is the transparent value. As a cell it's a clear pixel; as an op value it erases a region back to transparent — handy for carving shapes:

  sprite ring 16x16 {
    circle 8,8 7 #2a9d8f   // solid disc
    circle 8,8 4 .         // punch a transparent hole → a ring
  }

• Alpha in hex — #rgba or #rrggbbaa. #00000000 is fully transparent; partial alpha tints what's beneath:

  rect 0,0 15,15 #00000080   // 50%-opacity black wash

Order matters

sprite layered 8x8 {
  fill #f00      // red base
  fill #0f0      // green wins
  circle 4,4 2 #00f  // blue dot on top
}

Why ops over cells

For a 64×40 ship sprite:

• Cell grid: 2560 cell tokens, every one in the right column
• Ops: ~70 statements — fill sky, rect hull, line mast, etc.

LLMs are reliable at composing the latter. The cell grid form blows up on token alignment errors and there is no recovery.