Five freely combinable variants for floor, earth, rock and ore textures

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

art/generated/textures/PROMPTS.md

@@ -85,3 +85,19 @@ Keep this exact seamless tileable earth texture (same colours, same soil, same s
 Gold has four variants (`--size 128` and `--size 256` like the others). Silver, ruby and diamond
 have two variants: one seamless tile for both (`--size 64 --colors 32 --band 8` and
 `--size 128 --colors 48 --band 14`), copied to `assets/textures/<name>.png` and `<name>-128.png`.
+
+## Five variants per kind (2026-11-07)
+
+Floor, earth, rock and the ores (gold, silver, ruby, diamond) now have five tiles each that fit
+together in any order (`HD_SETS` in `src/gfx.rs`; a tile picks one by its position). No new
+pictures: `tools/make_tile.py --variants 5` takes the seamless sheet of a raw picture, makes one
+quarter of it seamless on its own as the shared border and fills the middles of the other tiles
+from other windows of the sheet:
+
+```bash
+python3 tools/make_tile.py <name>-raw.png <name> --size 256 --colors 48 --band 28 --variants 5   # 128x128 tiles
+python3 tools/make_tile.py <name>-raw.png <name> --size 128 --colors 32 --band 14 --variants 5   # 64x64 tiles
+```
+
+`<name>-v64.png` / `<name>-v128.png` are copied to `assets/textures/`; `<name>-v128-preview.png`
+shows a floor laid out at random. Water and lava keep their 2x2 blocks (they flow).