Source tree

Repository root

Path	Contents
source/	all engine Haxe code — 284 modules in 36 packages
source/source-haxelib-patches/	whole-file overrides of flixel, openfl, funkin.vis (details)
assets/	asset libraries: preload/, shared/, songs/, week*/, videos/, fonts/, embed/
mods/	user mods; ships with the bf-clicker example
example_mods/	modTemplate.zip and script templates
android/src/quack/fnf/phoenix/android/	Java injected into Android builds (PhoenixCore, PhoenixDisplay, PhoenixInput, PhoenixMedia, PhoenixMediaService, PhoenixStorage)
art/	icons and developer build scripts
setup/	haxelib bootstrap (windows.bat, unix.sh), MSVC fix, Android STL copy, URI registration
templates/	Lime project templates (manifests, HTML shell, plists)
tools/	repository tooling
tests/	test project
docs/	legacy docs: ANDROID_PLATFORM.md, script templates, the old JS Engine PDF
website/	this documentation site
project.hxp	the Lime project, written in Haxe (details)
hmm.json	pinned haxelib dependencies
checkstyle.json / hxformat.json	lint and formatter configuration
modsList.txt	enabled/disabled mods
gamemode.ini	Feral GameMode profile (Linux)

Documentation files at the root: README.md (features and the patch system), BUILDING.md (build instructions), CODESTYLE.md (per-language style rules), AGENTS.md (canonical instructions for AI agents), TODO.md, THECHANGELOG.md, URI.MD (the phoenix:// scheme).

Packages in source/

Package	Modules	Role
(root)	2	Main (entry point), import.hx (implicit imports)
backend	25	engine services — paths, prefs, conductor, controls, mods, state bases
backend.deeplink	2	phoenix:// URI parsing and routing
data	3	Song, Section, StageData — the chart/stage data model
debug	2 (+1)	FPS counter, memory sampling (debug.mem has a C++ include)
editors	10	chart, character, dialogue, week, menu-character, note-splash editors
editors.charting	7	grid, sections, waveform, selection, save/load, events
editors.helpers	4	per-editor helper modules
states	14	title, main menu, story, freeplay, mods, credits, achievements, loading, error
states.helpers	3	freeplay, mods menu, gameplay changers
states.substates	4	pause, game over, gameplay changers, reset score
play	3	PlayState, BaseStage, CutsceneHandler
play.helpers	14	the split halves of PlayState
play.objects	3	rating/judge/MS popups, sustain splash
objects	24	Note, Character, Alphabet, icons, dialogue, menu items
options	13	options menus and the Option model
options.helpers	2	note-colour preview, shared menu logic
psychlua	12	Lua/Python/HScript hosts, Convert, modchart sprites
psychlua.callbacks	15	the Lua standard library, grouped by topic
psychlua.pystdlib	11	the Python standard library
stages	13	hardcoded base-game stages
stages.objects	13	stage props (train, tankmen, A-Bot speaker, …)
shaders	42	GLSL effects, mostly *Shader + *Effect pairs
music	1	the freeplay music player
mobile	4 (+5)	touch controls, storage, first-run copy state
android	1 (+13)	JNI bridges and the Android platform services
utils	6	platform detection, native calls, memory, dates
headers	6	typedef re-export modules
flixel, flixel.addons.ui, flxanimate	2+	engine overrides of library classes

Naming and layout conventions

• One public type per module, file name equal to the type name.
• Helpers are static and take the owning state as the first parameter.
• *Shader / *Effect pairs: the shader holds the GLSL, the effect wraps it with animatable parameters and an update(elapsed).
• REFACTOR: comments mark code moved out of the old flat layout — they document where something came from, which is useful when porting a Psych patch.
• Platform-specific code lives in utils/, mobile/, android/ rather than inside gameplay files; gameplay code should rarely contain #if android.

See the code reference for a per-package type listing generated from the sources.