feat: added grapple mechanic

movement/states/state_grapple.gd

@@ -0,0 +1,86 @@
+extends Node
+class_name StateGrapple
+
+var machine: MovementStateMachine
+var params: MovementParams:
+	get: return machine.params
+
+func enter(_data: Dictionary = {}) -> void:
+	machine.on_ground = false
+	machine.wall_normal = Vector3.ZERO
+	machine.wall_side = 0.0
+	machine.register_chain_mechanic("grapple")
+
+func exit() -> void:
+	pass
+
+func update(delta: float) -> void:
+	var player := machine.player
+	var vel: Vector3 = player.velocity
+	
+	# If player releases the button, disconnect
+	if not machine.input_grapple:
+		machine.switch_to("air")
+		return
+
+	var grapple_pos: Vector3 = machine.grapple_point
+	var current_dist: float = player.global_position.distance_to(grapple_pos)
+	var dir_to_point: Vector3 = (grapple_pos - player.global_position).normalized()
+	
+	# Jump to detach and get a boost
+	if machine.input_jump_just_pressed and machine.jump_cooldown_timer <= 0.0:
+		vel.y = params.jump_velocity
+		# Add a directional boost if jumping while swinging
+		var h_look = machine.wish_dir_world
+		if h_look.length_squared() > 0.1:
+			var h_boost = h_look.normalized() * params.grapple_jump_boost
+			vel.x += h_boost.x
+			vel.z += h_boost.z
+			
+		player.velocity = vel
+		machine.jump_cooldown_timer = params.jump_cooldown
+		machine.register_chain_mechanic("grapple_jump")
+		machine.switch_to("air")
+		if player.jump_player:
+			player.jump_player.play()
+		return
+		
+	# Apply gravity
+	vel.y -= params.gravity * delta
+	
+	# Apply slight inward pull (reeling in)
+	vel += dir_to_point * params.grapple_pull_force * delta
+	
+	# Pendulum / Rope physics
+	# If the player tries to go further than the original rope length, pull them back aggressively
+	var max_len: float = machine.grapple_length
+	if current_dist > max_len:
+		# Project velocity onto the tangent of the sphere (prevent moving further away)
+		var radial_vel = vel.project(dir_to_point)
+		# If radial_vel is pointing AWAY from the grapple point (dot < 0), kill it
+		if radial_vel.dot(dir_to_point) < 0:
+			vel -= radial_vel
+			
+		# Add a spring force to pull them back to the sphere
+		var diff = current_dist - max_len
+		var spring_force = dir_to_point * diff * params.grapple_spring_strength
+		vel += spring_force * delta
+
+	# Air control while swinging
+	var wish_dir: Vector3 = machine.wish_dir_world
+	if wish_dir.length_squared() > 0.01:
+		wish_dir = wish_dir.normalized()
+		# Add force tangentially to the rope
+		# We want to steer, but not pull away from or directly into the rope.
+		var tangent_wish = wish_dir - wish_dir.project(dir_to_point)
+		if tangent_wish.length_squared() > 0.01:
+			vel += tangent_wish.normalized() * params.grapple_air_control * delta
+
+	player.velocity = vel
+	player.move_and_slide()
+
+	# Remove ground detach so players can grapple along the floor
+	# if player.is_on_floor():
+	# 	machine.on_ground = true
+	# 	machine.switch_to("ground")
+	# 	return