Sprite cases

A sprite case produces one small pixel image drawn onto the whole canvas. A sprite-sheet case produces a set of animation frames, each a completely separate file of the canvas size. Both are drawn with the drawing binaries, and both are scored on the image regenerated from the recorded action log.

Everything on the Manifests overview applies unchanged. This page covers the [canvas] table both kinds declare and the [sheet] table a sprite sheet adds.

asset_kind = "sprite"        # "sprite" (the default) | "sprite-sheet"

# The image the model draws on. For a single sprite this is the whole canvas; for
# a sprite sheet it is ONE frame (every frame is a separate file of this size).
[canvas]
width  = 64                  # canvas width in pixels (required, > 0)
height = 64                  # canvas height in pixels (required, > 0)
background = "transparent"   # initial canvas state: transparent | a hex color

# `draw` for a single sprite, `draw-sheet` for a sheet.
[tool]
binary  = "draw"
preview = "canvas.png"       # a {frame} template for a sheet, e.g. "frames/{frame}.png"

[output]
actions = "actions.json"     # a {frame} template for a sheet, e.g. "frames/{frame}.actions.json"

The canvas table

[canvas] fixes the image the model works on: its width and height in pixels and its initial background. For a single sprite this is the whole canvas; for a sprite sheet it describes one frame. Fixing it keeps runs comparable, the same way an end-to-end build interface does.

The declared canvas is seeded to the binary as its config, so the model’s drawing operations need no canvas flags.

The sheet table

The [sheet] table is required for, and only for, asset_kind = "sprite-sheet". It declares the case’s frames and the named sequences a reviewer plays back.

asset_kind = "sprite-sheet"

[tool]
binary  = "draw-sheet"
preview = "frames/{frame}.png"          # {frame} REQUIRED for a sheet

[output]
actions = "frames/{frame}.actions.json" # {frame} REQUIRED for a sheet

[sheet]

[[sheet.frame]]              # >=1 required; one declared frame
index  = 6                   # the index it is written to (draw-sheet --frame 6), unique

[[sheet.frame]]
index  = 7

[[sheet.sequence]]           # >=1 required; one named animation the UI plays back
slug   = "walk-right"        # stable slug (required, unique within the sheet)
name   = "Walk Right"        # display name (optional; default humanizes the slug)
frames = [6, 7]              # ordered frame indices (required, each a declared frame)
fps    = 4                   # playback rate in frames per second (required, > 0)

Each [[sheet.frame]] declares only the index it is written to, passed as draw-sheet --frame. The number of frames is however many are declared. Resolution validates that frame indices are unique, and that each sequence has a unique non-empty slug, at least one frames index, every index a declared frame, and fps > 0.

Each frame is regenerated independently, with no whole-sheet aggregate. The named sequences are surfaced to the reviewer and played back as live animations from the per-frame regenerated images. The sheet layout travels in the run record, so the verdict page animates from the run alone.