destroyulator/game/scripts/Juice.gd

extends Node
class_name Juice

## The feel layer. Everything that makes a smash *land* without adding simulation:
## hitstop, screenshake, per-material particle bursts, procedural impact audio, combos.
## Driven off Smashable's `smashed` signal (Main forwards it to impact()), so it's
## purely additive — the physics doesn't know this exists.
##
## Audio is SYNTHESIZED in code (AudioStreamWAV built from a generated PCM buffer),
## same zero-asset trick as dig.js. Each material gets its own little waveform.
##
## Godot 4.7 GDScript 2.0.

@export var shake_max_offset: float = 0.14   ## metres the camera jitters at full trauma
@export var shake_max_roll: float = 0.05     ## radians of camera roll at full trauma
@export var shake_decay: float = 1.6         ## trauma lost per second
@export var combo_window_ms: int = 1600      ## smashes within this window keep the combo alive
@export var hitstop_scale: float = 0.06      ## Engine.time_scale during a freeze-frame

var _cam: Camera3D
var _trauma: float = 0.0
var _hitstop_until_ms: int = 0
var _combo: int = 0
var _last_smash_ms: int = -100000
var _sounds: Dictionary = {}                 # kind -> AudioStreamWAV

func setup(cam: Camera3D) -> void:
	_cam = cam
	process_mode = Node.PROCESS_MODE_ALWAYS   # keep releasing hitstop even during a freeze
	for k in ["wood", "cardboard", "vinyl", "glass", "steel"]:
		_sounds[k] = _make_wav(_synth(k), 22050)

## Called once per shatter (Main forwards Smashable.smashed here).
func impact(kind: String, pos: Vector3, shards: int) -> void:
	var color: Color = Smashable.PROFILES.get(kind, Smashable.PROFILES["wood"])["color"]
	_burst(color, pos, clampi(shards + 4, 6, 26))
	_play_sound(kind, pos)
	add_trauma(0.26 + float(min(shards, 12)) * 0.03)
	_hitstop(0.04 + float(min(shards, 12)) * 0.005)

	var now := Time.get_ticks_msec()
	_combo = _combo + 1 if now - _last_smash_ms <= combo_window_ms else 1
	_last_smash_ms = now

func combo() -> int:
	return 0 if Time.get_ticks_msec() - _last_smash_ms > combo_window_ms else _combo

func add_trauma(a: float) -> void:
	_trauma = clampf(_trauma + a, 0.0, 1.0)

func _hitstop(dur: float) -> void:
	Engine.time_scale = hitstop_scale
	_hitstop_until_ms = maxi(_hitstop_until_ms, Time.get_ticks_msec() + int(dur * 1000.0))

func _process(delta: float) -> void:
	# release the freeze in REAL time (Time.get_ticks_msec is not scaled by time_scale)
	if Engine.time_scale < 1.0 and Time.get_ticks_msec() >= _hitstop_until_ms:
		Engine.time_scale = 1.0
	# screenshake: quadratic falloff feels punchier than linear
	if _cam != null:
		var amt := _trauma * _trauma
		_cam.position = Vector3(randf_range(-1.0, 1.0), randf_range(-1.0, 1.0), 0.0) * amt * shake_max_offset
		_cam.rotation.z = randf_range(-1.0, 1.0) * amt * shake_max_roll
		_trauma = maxf(0.0, _trauma - shake_decay * delta)

# ---------------------------------------------------------------- particles
func _burst(color: Color, pos: Vector3, count: int) -> void:
	var p := GPUParticles3D.new()
	p.one_shot = true
	p.explosiveness = 1.0
	p.amount = count
	p.lifetime = 0.7
	p.local_coords = false        # debris keeps falling in world space
	var pm := ParticleProcessMaterial.new()
	pm.emission_shape = ParticleProcessMaterial.EMISSION_SHAPE_SPHERE
	pm.emission_sphere_radius = 0.12
	pm.direction = Vector3(0, 1, 0)
	pm.spread = 78.0
	pm.initial_velocity_min = 1.4
	pm.initial_velocity_max = 4.6
	pm.gravity = Vector3(0, -9.8, 0)
	pm.scale_min = 0.3
	pm.scale_max = 1.1
	pm.angular_velocity_min = -420.0
	pm.angular_velocity_max = 420.0
	p.process_material = pm
	var mesh := BoxMesh.new()
	mesh.size = Vector3(0.04, 0.04, 0.04)
	var dmat := StandardMaterial3D.new()
	dmat.albedo_color = color
	mesh.material = dmat
	p.draw_pass_1 = mesh
	add_child(p)
	p.global_position = pos
	p.emitting = true
	p.finished.connect(p.queue_free)

# ---------------------------------------------------------------- audio
func _play_sound(kind: String, pos: Vector3) -> void:
	var wav: AudioStreamWAV = _sounds.get(kind)
	if wav == null:
		return
	var a := AudioStreamPlayer3D.new()
	a.stream = wav
	a.pitch_scale = randf_range(0.9, 1.14)   # per-hit variation so it never sounds looped
	a.unit_size = 6.0
	a.max_db = 4.0
	add_child(a)
	a.global_position = pos
	a.finished.connect(a.queue_free)
	a.play()

## Build a mono 16-bit AudioStreamWAV from a float[-1,1] sample buffer.
func _make_wav(samples: PackedFloat32Array, rate: int) -> AudioStreamWAV:
	var wav := AudioStreamWAV.new()
	wav.format = AudioStreamWAV.FORMAT_16_BITS
	wav.mix_rate = rate
	wav.stereo = false
	var bytes := PackedByteArray()
	bytes.resize(samples.size() * 2)
	for i in samples.size():
		bytes.encode_s16(i * 2, int(clampf(samples[i], -1.0, 1.0) * 32767.0))
	wav.data = bytes
	return wav

## Author each material's voice: noise + tuned sines shaped by a decay envelope.
##  wood = low dry crunch · cardboard = soft rip · vinyl = crack + warble
##  glass = bright tinkle · steel = ringing bonngg
func _synth(kind: String) -> PackedFloat32Array:
	var rate := 22050
	var dur := 0.26
	match kind:
		"glass": dur = 0.30
		"steel": dur = 0.55
		"vinyl": dur = 0.22
		"cardboard": dur = 0.18
	var n := int(rate * dur)
	var out := PackedFloat32Array()
	out.resize(n)
	for i in n:
		var t := float(i) / float(rate)
		var s := 0.0
		var env := 0.0
		match kind:
			"cardboard":
				env = exp(-t * 26.0)
				s = (randf() * 2.0 - 1.0) * 0.45 * env
			"vinyl":
				env = exp(-t * 16.0)
				var click := (randf() * 2.0 - 1.0) if t < 0.004 else 0.0
				s = click * 0.9 + sin(TAU * (520.0 - 300.0 * t) * t) * env * 0.5 + (randf() * 2.0 - 1.0) * 0.15 * env
			"glass":
				env = exp(-t * 34.0)
				s = (randf() * 2.0 - 1.0) * 0.5 * env + sin(TAU * 5200.0 * t) * 0.25 * env + sin(TAU * 3300.0 * t) * 0.2 * env
			"steel":
				env = exp(-t * 5.0)
				s = sin(TAU * 190.0 * t) * 0.5 * env + sin(TAU * 285.0 * t) * 0.25 * env + sin(TAU * 470.0 * t) * 0.12 * env + (randf() * 2.0 - 1.0) * 0.2 * exp(-t * 40.0)
			_:  # wood (and default)
				env = exp(-t * 20.0)
				s = (randf() * 2.0 - 1.0) * 0.7 * env + sin(TAU * 140.0 * t) * 0.4 * env
		out[i] = clampf(s, -1.0, 1.0)
	return out