Assets

The browser player receives the same smash.nes iNES ROM built in out/. make web-sync copies it to web/public/rom/smash.nes; Astro stages that file again for the final static site.

Asset	Source	Format
Playable ROM	out/smash.nes → web/public/rom/smash.nes	iNES .nes
Native captures	web/public/assets/captures/	256×240 PNG
Fighter sheets	src/chars/<id>/sheet.png	PNG, 32×40 source frames
Pixel font	web/public/assets/fonts/cartridge.woff2	WOFF2
Emulator runtime	web/public/assets/emulatorjs/data/	local JavaScript, CSS, JSON, and NES core data
Surface textures and icon	web/public/assets/	SVG

web/scripts/stage-assets.mjs clears web/.public/ before copying assets, so a removed source asset cannot survive a later build. It also places captures at snaps/ for browser checks and stages fighter sheets at assets/fighters/.

The Cartridge font is generated from the NES TILE1 glyphs in src/chr.s. Regenerate and validate it with:

uv run web/scripts/build-cartridge-font.py

Fighter sheets are authored data, not a web-only sprite sheet. Change a sheet or its character.toml, then run make generate; see build and testing.

Fighter packages

Each src/chars/<id>/ package pairs sheet.png with character.toml. The TOML is the source of truth for the fighter’s generated CHR, frame metadata, and animation timing; combat rules remain in src/main.c.

Section	Required fields	Purpose
[character]	id, display_name, runtime_slot	Identifies a contiguous runtime roster slot; franchise is optional metadata.
[spritesheet]	path, frame_width, frame_height	Locates the source PNG and its frame grid.
[[spritesheet.frames]]	name, x, y	Names a frame and gives its top-left pixel position; w and h are optional.
[[animations]]	name, frames, frame_duration	Selects named frames and their tick duration; looping defaults true and minimum_distinct_frames is optional.
[state_graph] / [[state_graph.states]]	initial; name, animation	Connects named animations to runtime states. Action states may set paired active_start/active_end or cancel_start/cancel_end ticks.

Mario’s walk is the minimal pattern: names refer to declared frames, and repeated frame names produce the cadence.

[[animations]]
name = "walk"
frames = ["walk_a", "walk_b", "walk_c", "walk_b"]
frame_duration = 5
looping = true

The generator validates frame, animation, and state references, then writes generated files under src/chars/<id>/generated/ and src/generated/. The full schema is in docs/spec_reference.md.

Music source

nessy/tools/music/rebuild_music.py reduces the locked MIDI source into nessy/assets/music.toml. make generate compiles that TOML into src/generated/music_data.h; edit the reducer policy rather than hand-editing generated C data.

TOML section	Key fields	Maps to
[timing]	ticks_per_beat, ntsc_frame_rate_num, ntsc_frame_rate_den	MIDI tick-to-NTSC-frame conversion
[[song]]	id, tempo_millibpm, order, loop_order	A named arrangement and loop point
[[song.pattern]]	id, ticks, pulse1, pulse2, triangle, noise	Equal-length event streams for the four NES voices

Pitch streams accept note names plus = to hold and - to rest. The noise stream accepts kick, snare, hat, rest, or hold. Run make rebuild-music to verify the locked source and regenerate music.toml, or make check-music for its offline check.