Baking a pack

A pack starts as a directory of SVGs and ends as a checked-in <id>.icons.axaml and pack.json. Baking happens at build time, only when the SVGs change, so consumers of your app never run the tool.

In your app

Install the baker into the project's tool manifest once:

dotnet new tool-manifest
dotnet tool install Avalloy.IconTool

Referencing the Avalloy.Icons package imports a targets file that bakes any IconPack items you declare before build:

<ItemGroup>
  <IconPack Include="lucide">
    <Name>Lucide</Name>
    <SrcDir>$(MSBuildProjectDirectory)\Assets\iconpacks\lucide</SrcDir>
    <OutDir>$(MSBuildProjectDirectory)\Assets\iconpacks\lucide</OutDir>
    <DuoDir></DuoDir>
    <Roles></Roles>
    <Description>Lucide (MIT)</Description>
    <Homepage>https://lucide.dev</Homepage>
    <Version>0.2.0</Version>
  </IconPack>
  <IconPackInput Include="$(MSBuildProjectDirectory)\Assets\iconpacks\lucide\*.svg" />
</ItemGroup>

IconPackInput is what makes it incremental: the target's inputs are your SVGs and its output the baked file, so an unchanged pack costs nothing. Set SkipBakeIconPacks=true to skip it entirely. The tool version is pinned in the manifest, so an upgrade is an explicit act; re-bake by touching an SVG or deleting the baked output.

By hand

avalloy-icontool create --id lucide --name Lucide --src Assets/iconpacks/lucide --out Assets/iconpacks/lucide \
    [--duo <duoDir>] [--roles <icons.md>] [--desc <text>] [--homepage <url>] [--version <v>] [--ns <controlNamespace>]

--ns sets the control namespace the emitted dictionary imports, so the same writer serves any consuming app.

Duotone and small variants

Two conventions the flattener understands. A duotone icon is a two-tone active SVG in a parallel --duo directory: the back layer carries an opacity attribute, the front layer does not, and the baker keeps both so GlyphIcon can swap to the lit layer on hover. A small variant is a simplified drawing used at sizes up to a threshold, fed to the baker alongside the base glyph.

What the pure library does

SvgFlattener turns SVG text into Avalonia path data: path, circle and rect, a baked translate-plus-scale transform, fill-rule detection, and the opacity-split duotone convention. IconBaker composes a full IconGlyphSpec from the base, duotone and small variant SVGs, taking fill and stroke metadata from the source so stroke-only Lucide glyphs bake correctly. IconPackWriter emits the dictionary and the manifest as strings. None of it touches a file, which is what lets the same code run at build time in the tool and at load time in Core for user packs, and be tested without either.