# FieldCraft application icon

FieldCraft's mark is a cube in isometric view, covered by a structured hexahedral mesh, whose
faces carry a banded colour fringe (blue to red, hottest at the front corner) as a stress or
temperature result would. Streamlines coloured by flow speed in the same bands, with arrowheads,
sweep in from the lower left: two run into the top face and narrow into its mesh lines, so the
flow becomes the structure, and one wraps around the cube. Its faces are separated by
transparent gaps rather than painted edge lines, so the backdrop shows through them in every
appearance. It is original artwork, attributed in `ATTRIBUTION.md`, and shares the Craft
family's layout (rounded-square backdrop, isometric floor grid, lit top faces).

Everything here is generated by `cargo xtask app-icon` (`xtask/src/app_icon.rs`), which computes
the geometry and draws it with VectorCraft's command-line tool (`VECTORCRAFT_CLI`, else
`vectorcraft-cli` on the PATH). Change the recipe there and rerun it; do not edit the exports by
hand. It runs on macOS (sips, iconutil, `xcrun actool`) with ImageMagick (`magick`) installed.

| File | What it is |
|---|---|
| `icon.vectorcraft`, `icon.svg`, `icon.png` | The full icon on its backdrop, 1024 × 1024 |
| `icon-small.vectorcraft`, `icon-small.svg`, `icon-small.png` | Small-size artwork used at 16–32 px: the fringe cube and one bold coloured streamline with an arrowhead, no mesh or floor grid, faces edge to edge |
| `icon.iconset/`, `icon.icns` | macOS iconset (sips) and its iconutil compilation |
| `icon.ico` | Windows icon, 16–256 px |
| `FieldCraft.icon/` | Icon Composer document: floor grid (Default and Dark), flow behind, cube (faces and mesh) and flow in front layers, each scaled to 90% |
| `layers/*.vectorcraft` | Editable sources of the Icon Composer layers |
| `Assets.car` | `actool` compilation of `FieldCraft.icon` for macOS 26 and later (needs Xcode 26 or later; the task skips it with a note otherwise) |

The desktop app embeds `icon.iconset/icon_128x128@2x.png` as its window and Dock icon
(`apps/fieldcraft/src/main.rs`). The release packages (docs/releasing.md) use the rest:
`packaging/macos/package.sh` copies `Assets.car` and `icon.icns` (as `FieldCraft.icns`) into
`FieldCraft.app/Contents/Resources`, named by `CFBundleIconName` / `CFBundleIconFile`;
`apps/fieldcraft/build.rs` embeds `icon.ico` in `fieldcraft.exe`; and
`packaging/linux/package.sh` installs the iconset PNGs as the hicolor icons.