Pixel-art import

Dev tooling, not shipped in the app.

• gen_seed_pngs.py regenerates the hand-authored seed shapes into app/src/main/assets/pictures/.
• PixelPackImporter (a guarded JVM test in app/src/test/.../tools/) batch converts a vendored CC0 pack into validated picture PNGs.

Adding a silhouette pack

Solid single-shape silhouettes work; detailed multi-colour sprites do not (they binarise into noise). The current source is game-icons.net (CC-BY-3.0).

1. Vendor PNGs into tools/pixel-import/source/ named <author>--<icon>.png (the <author> before -- becomes the per-icon CC-BY credit). For game-icons.net, rasterise the SVGs (e.g. magick -background none in.svg -resize 96x96 out.png). The dir is gitignored; not shipped.

2. Run the importer:

   RUN_IMPORTER=1 ./gradlew :app:testDebugUnitTest --tests "*PixelPackImporter*"
   

It trims each tile to content, scales to 15 (or 10), binarizes with the same rule the app uses, and keeps only tiles that are uniquely solvable with no empty row or column. Output PNGs land in app/src/main/assets/pictures/ and CC0 credit rows are merged into app/src/main/assets/pictures_credits.tsv. Re-running is idempotent.

Source packs may be committed here (CC0 permits redistribution) so the import is reproducible; they are outside src/main and never ship in the APK.