Cinderwild/scripts/creatures/creature.gd

extends AnimatableBody3D
## A wild animal: rabbit, deer or boar.
##
## Movement is steering over the heightmap, with no navmesh. The animal walks
## toward a heading, probes the ground ahead (water, cliffs, the world edge,
## trees, rocks and buildings) and turns away from anything it can't cross.
##
## States:
## - idle: stands and grazes.
## - wander: ambles in one direction.
## - flee: runs away from a threat. Rabbits zig-zag.
## - charge: a hit boar runs at you and gores you.
## - dead: a carcass. E butchers it for meat and hide, and gives back any
##   arrows stuck in it.
##
## step(dt) holds all the logic so tests can drive it directly. Lives on
## physics layer 4 (value 8): hit by weapons and arrows, but the player walks
## through it. A carcass moves to layer 2, like other interactables.

signal died(creature: Node)

const Meshes = preload("res://scripts/creatures/creature_meshes.gd")
const LAYER := 8

## Tuning per kind. Speeds in m/s (the player walks at 5 and sprints at 8).
const KINDS := {
	"rabbit": {"name": "Rabbit", "hp": 10.0, "walk": 1.4, "run": 7.0, "turn": 9.0,
		"notice": 7.0, "notice_loud": 12.0, "calm": 18.0,
		"drops": {"raw_meat": [1, 1]}},
	"deer": {"name": "Deer", "hp": 40.0, "walk": 1.3, "run": 9.0, "turn": 4.5,
		"notice": 16.0, "notice_loud": 30.0, "calm": 45.0,
		"drops": {"raw_meat": [2, 3], "hide": [1, 2]}},
	"boar": {"name": "Boar", "hp": 60.0, "walk": 1.2, "run": 6.6, "turn": 5.0,
		"notice": 0.0, "notice_loud": 0.0, "calm": 30.0,
		"damage": 14.0, "attack_range": 1.7, "attack_cd": 1.6, "aggro": 18.0,
		"drops": {"raw_meat": [3, 4], "hide": [1, 2]}},
	# Wolves are driven by wolf.gd + wolf_pack.gd; "notice" is unused.
	"wolf": {"name": "Wolf", "hp": 45.0, "walk": 1.6, "run": 8.6, "turn": 6.0,
		"notice": 0.0, "notice_loud": 0.0, "calm": 40.0,
		"damage": 9.0, "attack_range": 1.8, "attack_cd": 1.2,
		"drops": {"raw_meat": [1, 2], "wolf_pelt": [1, 1]}},
}
const CARCASS_SECONDS := 300.0

var kind := "deer"
var def: Dictionary
var hp := 40.0
var state := "idle"
var world: Node3D
var terrain: Node3D
var player: Node3D
var rng := RandomNumberGenerator.new()
var embedded := {}                 ## item id -> count (arrows stuck in it)
var carcass_left := CARCASS_SECONDS

var yaw := 0.0
var target_yaw := 0.0
var speed := 0.0
var _state_t := 0.0
var _threat := Vector3.ZERO
var _aggro := 0.0
var _attack_cd := 0.0
var _zig := 0.0
var _phase := 0.0
var _visual: Node3D
var _legs: Array[Node3D] = []
var _flash := 0.0
var _detour_t := 0.0               ## > 0: following a detour round an obstacle
var _detour_side := 1.0

## Sets the heading, unless the animal is in the middle of a detour.
func steer(y: float) -> void:
	if _detour_t <= 0.0:
		target_yaw = y
var _mat: StandardMaterial3D
var _hit_mat: StandardMaterial3D

func setup(k: String, w: Node3D, pos: Vector3, seed: int) -> void:
	kind = k
	def = KINDS[k]
	hp = def.hp
	world = w
	terrain = w.terrain
	player = w.player
	rng.seed = seed
	name = "%s_%d" % [k, absi(seed) % 100000]
	collision_layer = LAYER
	collision_mask = 0
	sync_to_physics = false
	add_to_group("creature")
	var parts: Dictionary = Meshes.build(k)
	_mat = ItemDB.item_material()
	_hit_mat = StandardMaterial3D.new()
	_hit_mat.vertex_color_use_as_albedo = true
	_hit_mat.vertex_color_is_srgb = true
	_hit_mat.albedo_color = Color(1.6, 0.5, 0.45)
	_visual = Node3D.new()
	add_child(_visual)
	var body := MeshInstance3D.new()
	body.mesh = parts.body
	body.material_override = _mat
	_visual.add_child(body)
	if parts.has("eyes"):
		# Eyes that catch the light: you see a wolf's eyes in the dark first.
		var eyes := MeshInstance3D.new()
		eyes.mesh = parts.eyes
		var em := StandardMaterial3D.new()
		em.albedo_color = Color(1.0, 0.85, 0.4)
		em.emission_enabled = true
		em.emission = Color(1.0, 0.75, 0.3)
		em.emission_energy_multiplier = 2.5
		eyes.material_override = em
		eyes.set_meta("keep_mat", true)
		_visual.add_child(eyes)
	for h: Vector3 in parts.hips:
		var pivot := Node3D.new()
		pivot.position = h
		var leg := MeshInstance3D.new()
		leg.mesh = parts.leg
		leg.material_override = _mat
		pivot.add_child(leg)
		_visual.add_child(pivot)
		_legs.append(pivot)
	var cs := CollisionShape3D.new()
	var cap := CapsuleShape3D.new()
	cap.radius = parts.radius
	cap.height = maxf(parts.height, parts.radius * 2.0 + 0.01)
	cs.shape = cap
	cs.position = Vector3(0, parts.height * 0.5, 0)
	if k != "rabbit":
		# Long bodies: lay the capsule along the spine.
		cap.height = {"deer": 1.5, "boar": 1.4, "wolf": 1.25}.get(k, 1.4)
		cs.rotation.x = PI * 0.5
		cs.position = Vector3(0, parts.height * 0.55, 0)
	add_child(cs)
	yaw = rng.randf() * TAU
	target_yaw = yaw
	_state_t = rng.randf_range(1.0, 4.0)
	position = Vector3(pos.x, terrain.sample_height(pos.x, pos.z), pos.z)   # (spawner sits at the origin)
	rotation.y = yaw

func display_name() -> String:
	return def.name

func is_dead() -> bool:
	return state == "dead"

func interact_prompt(p: Node) -> String:
	if is_dead():
		return "%s carcass  [E] Butcher" % def.name
	var s: String = def.name
	if kind == "boar":
		s = "Boar (angry!)" if _aggro > 0.0 else "Boar (leaves you alone unless you hit it)"
	var held: Dictionary = ItemDB.get_item(p.held_item_id())
	if not Actions.melee_stats(p).armed and not held.has("bow"):
		s += "  (you need a weapon: club, spear, bow or axe)"
	return s

func interact(p: Node) -> void:
	if is_dead():
		Actions.butcher(p, self)

func _physics_process(delta: float) -> void:
	step(delta)

func step(dt: float) -> void:
	if _flash > 0.0:
		_flash -= dt
		if _flash <= 0.0:
			_set_material(_mat)
	if puppet:
		_puppet_step(dt)
		return
	if is_dead():
		carcass_left -= dt
		if carcass_left <= 0.0:
			queue_free()
		return
	_attack_cd = maxf(_attack_cd - dt, 0.0)
	_aggro = maxf(_aggro - dt, 0.0)
	# Who it's reacting to: the player (or on a server, the nearest one).
	var t := _pick_target()
	if t != null:
		player = t
		_think(dt)
	elif state in ["flee", "charge"]:
		state = "idle"   # nobody about
	_move(dt)
	_animate(dt)

func _pick_target() -> Node3D:
	return world.nearest_player(global_position)

# --- on a client playing online: the server's animal, shown here ------------

## A puppet only shows what the server's copy is doing (creature_net.gd):
## no thinking, no damage dealt. It can still be hit (that's sent to the
## server) and butchered.
var puppet := false
var _net_pos := Vector3.ZERO
var _net_yaw := 0.0

func net_update(pos: Vector3, y: float, st: String, spd: float, new_hp: float) -> void:
	if not puppet:
		return
	_net_pos = pos
	_net_yaw = y
	speed = spd
	if new_hp < hp - 0.01 and st != "dead":
		_flash = 0.15
		_set_material(_hit_mat)
		_burst()
	hp = new_hp
	if st == "dead" and state != "dead":
		_burst()
		_die(global_position + global_basis.z)
		return
	if state != "dead":
		state = st

func _puppet_step(dt: float) -> void:
	if is_dead():
		return
	var k := 1.0 - exp(-12.0 * dt)
	var p := global_position.lerp(_net_pos, k)
	if p.distance_to(_net_pos) > 6.0:
		p = _net_pos   # (a jump: a wolf slipping home to the den)
	global_position = p
	yaw = lerp_angle(yaw, _net_yaw, k)
	rotation.y = yaw
	_animate(dt)

## Whether the player is close enough to be noticed. Sprinting, or moving
## fast while swimming or jumping, is loud.
func _notices_player(d: float) -> bool:
	if def.notice <= 0.0:
		return false
	var loud: bool = player.velocity.length() > 6.0
	return d < (def.notice_loud if loud else def.notice)

func _think(dt: float) -> void:
	var pp: Vector3 = player.global_position
	var d := global_position.distance_to(pp)
	_state_t -= dt
	match state:
		"idle", "wander":
			if _notices_player(d):
				_start_flee(pp)
			elif _state_t <= 0.0:
				if state == "idle":
					state = "wander"
					target_yaw = yaw + rng.randf_range(-1.6, 1.6)
					_state_t = rng.randf_range(3.0, 8.0)
				else:
					state = "idle"
					_state_t = rng.randf_range(2.0, 6.0)
		"flee":
			if _notices_player(d):
				_threat = pp
			var away := global_position - _threat
			target_yaw = atan2(-away.x, -away.z)   # heading along `away` (forward is -Z)
			if kind == "rabbit":
				_zig -= dt
				if _zig <= 0.0:
					_zig = rng.randf_range(0.3, 0.7)
					target_yaw += rng.randf_range(-0.9, 0.9)
			if d > def.calm and _state_t <= 0.0:
				state = "idle"
				_state_t = rng.randf_range(2.0, 5.0)
		"charge":
			var to := pp - global_position
			target_yaw = atan2(-to.x, -to.z)
			if _aggro <= 0.0 or d > 45.0:
				state = "wander"
				_state_t = 4.0
			elif d < def.attack_range and _attack_cd <= 0.0:
				_attack_cd = def.attack_cd
				player.survival.damage(def.damage * world.difficulty_mult("damage"), global_position, "a " + String(def.name).to_lower())

func _start_flee(from: Vector3) -> void:
	state = "flee"
	_threat = from
	_state_t = 4.0

func _desired_speed() -> float:
	match state:
		"wander": return def.walk
		"flee", "charge": return def.run
	return 0.0

func _move(dt: float) -> void:
	var want := _desired_speed()
	speed = move_toward(speed, want, dt * (def.run * 2.5))
	yaw = rotate_toward(yaw, target_yaw, def.turn * dt)
	if speed < 0.01:
		return
	_detour_t = maxf(_detour_t - dt, 0.0)
	var dir := Vector3(-sin(yaw), 0, -cos(yaw))
	if _blocked(dir):
		# Turn away and keep to the new heading for a moment (a detour), so
		# an animal heading somewhere slides round an obstacle instead of
		# turning straight back into it. Keep turning the same way while
		# still blocked.
		if _detour_t <= 0.0:
			_detour_side = 1.0 if rng.randf() < 0.5 else -1.0
		var turn := rng.randf_range(0.8, 1.6) * _detour_side
		target_yaw = yaw + turn
		yaw += turn * 0.35
		_detour_t = rng.randf_range(1.0, 1.8)
		speed *= 0.5
		if state == "charge":
			return
		dir = Vector3(-sin(yaw), 0, -cos(yaw))
		if _blocked(dir):
			return
	var p := global_position + dir * speed * dt
	p.y = terrain.sample_height(p.x, p.z)
	global_position = p
	rotation.y = yaw

## Something ahead the animal can't or won't cross.
func _blocked(dir: Vector3) -> bool:
	var probe := global_position + dir * (1.4 + speed * 0.15)
	if not terrain.inside_boundary(probe.x, probe.z, 6.0):
		return true
	var h: float = terrain.sample_height(probe.x, probe.z)
	if h < terrain.water_level + 0.2:
		return true
	if absf(h - global_position.y) > 1.1:
		return true
	# Trees, rocks and buildings at chest height (the terrain isn't on this test).
	var from := global_position + Vector3(0, 0.45, 0)
	var q := PhysicsRayQueryParameters3D.create(from, Vector3(probe.x, h + 0.45, probe.z), 1)
	q.exclude = [get_rid(), terrain.get_node("TerrainBody").get_rid()]
	return not get_world_3d().direct_space_state.intersect_ray(q).is_empty()

func _animate(dt: float) -> void:
	if state == "rest":
		# Lying down: body lowered, legs folded under.
		_visual.position.y = lerpf(_visual.position.y, -0.3, minf(dt * 3.0, 1.0))
		_visual.rotation.x = lerpf(_visual.rotation.x, 0.0, minf(dt * 4.0, 1.0))
		for l in _legs:
			l.rotation.x = lerpf(l.rotation.x, 1.35 * (1.0 if l.position.z < 0.0 else -1.0), minf(dt * 3.0, 1.0))
		return
	var k := speed / maxf(def.run, 0.01)
	_phase += dt * (3.0 + speed * 2.2)
	var amp := clampf(speed / 2.0, 0.0, 1.0) * 0.6
	for i in range(_legs.size()):
		# Diagonal pairs move together (a trot); rabbits hop with both
		# hind legs at once.
		var off := 0.0 if i in [0, 3] else PI
		if kind == "rabbit":
			off = 0.0 if i < 2 else PI * 0.6
		_legs[i].rotation.x = sin(_phase + off) * amp
	_visual.position.y = absf(sin(_phase)) * (0.06 if kind == "rabbit" else 0.03) * k
	if state == "idle" and kind != "rabbit":
		# Grazing: head (whole body) dips a little now and then.
		_visual.rotation.x = lerpf(_visual.rotation.x, 0.08 * maxf(sin(_state_t * 1.3), 0.0), dt * 2.0)
	else:
		_visual.rotation.x = lerpf(_visual.rotation.x, 0.0, dt * 4.0)

# --- combat -------------------------------------------------------------------

## Applies a hit (Actions validates who hit what). `from` = where it came
## from, for the reaction.
func take_hit(damage: float, from: Vector3, embed_id: String = "") -> void:
	if puppet:
		return   # (online the server's copy takes the hit)
	if is_dead():
		if not embed_id.is_empty():
			embedded[embed_id] = embedded.get(embed_id, 0) + 1
		return
	hp -= damage
	if not embed_id.is_empty():
		embedded[embed_id] = embedded.get(embed_id, 0) + 1
	_flash = 0.15
	_set_material(_hit_mat)
	_burst()
	if hp <= 0.0:
		_die(from)
		return
	_react(from)

## How a living animal responds to being hit (wolves override this).
func _react(from: Vector3) -> void:
	if kind == "boar" and hp > def.hp * 0.3:
		state = "charge"
		_aggro = def.aggro
		_attack_cd = 0.4
	else:
		_start_flee(from)
		_state_t = 6.0

func _die(from: Vector3) -> void:
	state = "dead"
	speed = 0.0
	hp = 0.0
	_flash = 0.0
	_set_material(_mat)
	remove_from_group("creature")
	add_to_group("carcass")
	collision_layer = 2
	for l in _legs:
		l.rotation.x = 0.4
	if puppet:
		_visual.rotation.z = -PI * 0.5
		return
	# Topple onto its side, away from the blow.
	var side := 1.0 if (global_position - from).dot(global_basis.x) > 0.0 else -1.0
	if is_inside_tree() and DisplayServer.get_name() != "headless":
		var tw := create_tween()
		tw.tween_property(_visual, "rotation:z", -side * PI * 0.5, 0.45).set_trans(Tween.TRANS_QUAD).set_ease(Tween.EASE_IN)
	else:
		_visual.rotation.z = -side * PI * 0.5
	died.emit(self)

## What butchering gives (rolled once).
func butcher_drops() -> Dictionary:
	var out := {}
	for id in def.drops:
		var r: Array = def.drops[id]
		out[id] = rng.randi_range(int(r[0]), int(r[1]))
	for id in embedded:
		out[id] = out.get(id, 0) + int(embedded[id])
	return out

func _set_material(m: Material) -> void:
	for c in _visual.get_children():
		if c is MeshInstance3D and not c.has_meta("keep_mat"):
			c.material_override = m
		for g in c.get_children():
			if g is MeshInstance3D and not g.has_meta("keep_mat"):
				g.material_override = m

func _burst() -> void:
	if not is_inside_tree() or DisplayServer.get_name() == "headless":
		return
	var p := CPUParticles3D.new()
	var box := BoxMesh.new()
	box.size = Vector3.ONE * 0.05
	var m := StandardMaterial3D.new()
	m.albedo_color = Color(0.55, 0.08, 0.06)
	box.material = m
	p.mesh = box
	p.amount = 12
	p.one_shot = true
	p.explosiveness = 0.95
	p.lifetime = 0.6
	p.spread = 60.0
	p.initial_velocity_min = 1.5
	p.initial_velocity_max = 3.0
	p.gravity = Vector3(0, -10, 0)
	world.add_child(p)
	p.global_position = global_position + Vector3(0, Meshes.build(kind).height * 0.6, 0)
	p.emitting = true
	p.finished.connect(p.queue_free)