Claude 82b3d0d20a metatiles + collision: metatileset, room, paint_room, collides_at ... Closes §H. 2×2 metatiles and a parallel collision map are now a first-class construct. `metatileset Name { metatiles: [{ id, tiles, collide }, ...] }` declares a library of 2×2 tile bundles. `room Name { metatileset: M, layout: [...] }` lays them out on a 16×15 grid. The compiler expands each room at compile time into: - a 960-byte nametable (`__room_tiles_<name>`) - a 64-byte attribute table (`__room_attrs_<name>`) - a 240-byte collision bitmap (`__room_col_<name>`) `paint_room Name` reuses the vblank-safe `load_background` update machinery for the nametable blit and installs the collision bitmap pointer into `ZP_ROOM_COL_LO`/`ZP_ROOM_COL_HI` (ZP $18/$19). `collides_at(x, y)` JSRs into a small runtime helper that reads `(room_col),Y` with `Y = (y & 0xF0) | (x >> 4)` and returns 0/1. The helper links in only when the `__collides_at_used` marker is emitted, so programs that declare a room but never query it pay zero bytes for the subroutine. `parse_byte_array` grows a `[value; count]` shortcut — 240-entry `layout` arrays are unwieldy to spell out a byte at a time. See `examples/metatiles_demo.ne` for the end-to-end flow: a probe sprite bounces off walls via `collides_at` and lands on the left side of the playfield at frame 180 — direct evidence that the collision query works. Also defers the register-allocator work from §"Code quality / tooling" and documents the audio-goldens constraint in future-work so the next agent sees it.		2026-04-19 01:28:17 +00:00
..
mod.rs	metatiles + collision: metatileset, room, paint_room, collides_at	2026-04-19 01:28:17 +00:00
tests.rs	codegen: make var_addrs misses panic loudly and fix latent struct-field silent drop	2026-04-17 23:49:29 +00:00