Initial commit: Godot 4.7 pixel platformer prototype

Player: move/jump (Space), test flight (F, debug builds only). Key: pickup, hold S to aim with live trajectory preview, release to throw, W to warp to the thrown key. Spring bounce. Spikes deal damage. 3-heart health, Z consumes a heal item for +1 heart and a 5s shield. HUD with hearts and item count. Death screen with fade-to-black and restart. Hidden passages. Assets: Kenney Pixel Platformer (CC0).

scripts/collectible.gd

@@ -0,0 +1,14 @@
+extends Area2D
+
+## 走到就捡走，给玩家增加一次"回血道具"。
+## 碰撞掩码已经限制成只检测玩家那一层，所以进到这里的一定是玩家。
+
+
+func _ready() -> void:
+	body_entered.connect(_on_body_entered)
+
+
+func _on_body_entered(body: Node2D) -> void:
+	if body.has_method("add_heal_item"):
+		body.add_heal_item()
+		queue_free()

scripts/collectible.gd.uid

@@ -0,0 +1 @@
+uid://dcemiea0m0t48

scripts/death_screen.gd

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+extends CanvasLayer
+
+## 生命值归零后的死亡界面：画面渐黑 + 重新开始按钮。
+## 只负责显示和重启，死亡状态由玩家（is_dead）决定。
+
+signal restart_requested
+
+@export var fade_time: float = 1.0
+## 渐黑完成后再过多久显示标题和按钮
+@export var button_delay: float = 0.4
+
+var _player: Node = null
+var _fade: ColorRect = null
+var _center: CenterContainer = null
+var _button: Button = null
+var _elapsed: float = 0.0
+var _dying: bool = false
+
+
+func _ready() -> void:
+	visible = false
+	_fade = get_node_or_null("Fade")
+	_center = get_node_or_null("Center")
+	_button = get_node_or_null("Center/VBox/RestartButton")
+	if _button != null:
+		_button.pressed.connect(restart)
+	if _fade != null:
+		_fade.color = Color(0.0, 0.0, 0.0, 0.0)
+	if _center != null:
+		_center.visible = false
+
+
+func _process(delta: float) -> void:
+	if not _dying:
+		if _player == null or not is_instance_valid(_player):
+			_player = get_tree().get_first_node_in_group("player")
+			if _player == null:
+				return
+		if bool(_player.is_dead):
+			_dying = true
+			visible = true
+		else:
+			return
+
+	_elapsed += delta
+	if _fade != null:
+		_fade.color = Color(0.0, 0.0, 0.0, clampf(_elapsed / maxf(fade_time, 0.01), 0.0, 1.0))
+	if _center != null and _elapsed >= fade_time + button_delay:
+		_center.visible = true
+
+
+func _unhandled_input(event: InputEvent) -> void:
+	if not _dying:
+		return
+	var key := event as InputEventKey
+	if key != null and key.pressed and not key.echo:
+		if key.physical_keycode == KEY_R or key.physical_keycode == KEY_ENTER:
+			restart()
+
+
+func restart() -> void:
+	restart_requested.emit()
+	get_tree().paused = false
+	get_tree().reload_current_scene()

scripts/death_screen.gd.uid

@@ -0,0 +1 @@
+uid://b31yxkyym11xb

scripts/hazard.gd

@@ -0,0 +1,14 @@
+extends Area2D
+
+## 尖刺：碰到就把角色打回出生点。
+## 碰撞掩码已经限制成只检测玩家那一层，所以进到这里的一定是玩家。
+@export var damage: int = 1
+
+
+func _ready() -> void:
+	body_entered.connect(_on_body_entered)
+
+
+func _on_body_entered(body: Node2D) -> void:
+	if body.has_method("hurt"):
+		body.hurt(damage)

scripts/hazard.gd.uid

@@ -0,0 +1 @@
+uid://bkhda0ohbgla2

scripts/hidden_passages.gd

@@ -0,0 +1,83 @@
+extends Node2D
+
+const ATLAS := preload("res://assets/game/tilesets/kenney_tiles_atlas.png")
+const TILE := 18
+
+## 隐藏通道：下面这些格子在关卡开始时会被"挖空"，
+## 原本是实心石壁的地方就变成能穿过去的暗道。
+## 坐标是格坐标（格边长 18px），改这里就能挪位置。
+@export var hidden_cells: Array = [
+	# ① 主线走廊上的石柱（第 13 列第 6~7 行）
+	Vector2i(13, 6), Vector2i(13, 7),
+
+	# ② 低层暗道（第 11 行第 12~15 列）
+	Vector2i(12, 11), Vector2i(13, 11), Vector2i(14, 11), Vector2i(15, 11),
+]
+
+## 伪装贴图所在层：要低于角色(z=10)、高于地形(z=0~2)
+@export var cover_z_index: int = 3
+## 是否给洞口盖上"假墙"（关掉的话洞口会明显地露出来）
+@export var hide_with_cover: bool = true
+
+
+func _ready() -> void:
+	var layers := _tile_layers()
+	if layers.is_empty():
+		return
+	var base: TileMapLayer = layers[0]
+
+	# 先把盖子做好（此时参考的那块墙还在），再挖空
+	var covers: Array = []
+	for cell in hidden_cells:
+		covers.append([cell, _make_cover(cell) if hide_with_cover else null])
+
+	for cell in hidden_cells:
+		for layer in layers:
+			layer.erase_cell(cell)
+
+	for pair in covers:
+		var sprite: Sprite2D = pair[1]
+		if sprite != null:
+			add_child(sprite)
+			sprite.global_position = base.to_global(base.map_to_local(pair[0]))
+
+
+func _tile_layers() -> Array:
+	var out: Array = []
+	for child in get_children():
+		if child is TileMapLayer:
+			out.append(child)
+	return out
+
+
+## 借用正下方最近一块实心墙的贴图，做成一个完全没有碰撞的 Sprite2D
+func _make_cover(cell: Vector2i) -> Sprite2D:
+	var found := Vector2i(-1, -1)
+	for dy in range(1, 6):
+		for layer in _tile_layers():
+			var probe: Vector2i = cell + Vector2i(0, dy)
+			var source_id: int = layer.get_cell_source_id(probe)
+			if source_id == -1:
+				continue
+			var coords: Vector2i = layer.get_cell_atlas_coords(probe)
+			var source := layer.tile_set.get_source(source_id) as TileSetAtlasSource
+			if source == null:
+				continue
+			var data: TileData = source.get_tile_data(coords, 0)
+			if data != null and data.get_collision_polygons_count(0) > 0:
+				found = coords
+				break
+		if found.x >= 0:
+			break
+	if found.x < 0:
+		return null
+
+	var atlas_texture := AtlasTexture.new()
+	atlas_texture.atlas = ATLAS
+	atlas_texture.region = Rect2(found.x * TILE, found.y * TILE, TILE, TILE)
+
+	var sprite := Sprite2D.new()
+	sprite.texture = atlas_texture
+	sprite.texture_filter = CanvasItem.TEXTURE_FILTER_NEAREST
+	sprite.z_index = cover_z_index
+	return sprite

scripts/hidden_passages.gd.uid

@@ -0,0 +1 @@
+uid://dxwa7fxghp3a2

scripts/hud.gd

@@ -0,0 +1,45 @@
+extends CanvasLayer
+
+## 左上角的状态显示：3 颗心 + 回血道具数量 + 护盾剩余时间。
+## 每帧从场景里找带 "player" 组的玩家读取状态。
+
+@export var full_heart_texture: Texture2D
+@export var empty_heart_texture: Texture2D
+
+var _player: Node = null
+var _hearts: Array = []
+var _count_label: Label = null
+var _shield_label: Label = null
+
+
+func _ready() -> void:
+	for i in range(1, 4):
+		var heart := get_node_or_null("Heart%d" % i)
+		if heart != null:
+			_hearts.append(heart)
+	_count_label = get_node_or_null("CountLabel")
+	_shield_label = get_node_or_null("ShieldLabel")
+
+
+func _process(_delta: float) -> void:
+	if _player == null or not is_instance_valid(_player):
+		_player = get_tree().get_first_node_in_group("player")
+		if _player == null:
+			return
+
+	var health: int = int(_player.health)
+	for i in _hearts.size():
+		var heart: TextureRect = _hearts[i]
+		heart.texture = full_heart_texture if i < health else empty_heart_texture
+
+	var items: int = int(_player.heal_items)
+	if _count_label != null:
+		_count_label.text = "x%d" % items
+		_count_label.modulate = Color.WHITE if items > 0 else Color(1.0, 1.0, 1.0, 0.4)
+
+	if _shield_label != null:
+		var shield: float = float(_player.shield_left)
+		if shield > 0.0:
+			_shield_label.text = "SHIELD %.1fs" % shield
+		else:
+			_shield_label.text = ""

scripts/hud.gd.uid

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+uid://8o2g2u6clfh6

scripts/key.gd

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+extends Area2D
+
+signal collected
+
+## 钥匙中心到"脚底"的距离：射线从脚底出发，落地时钥匙正好站在表面上
+const FOOT_OFFSET := 7.0
+const STEP := 1.0 / 60.0
+const MAX_STEPS := 240
+
+enum State { IDLE, THROWN, LANDED }
+
+## 关卡里那把钥匙原本是用 TerrainBase 的一块地砖画的。
+## 这个开关让钥匙对象在开场时把脚下那块占位地砖擦掉，避免两个钥匙重叠。
+@export var erase_placeholder_on_ready: bool = true
+## 落地后多久才允许再次被捡起
+@export var settle_time: float = 0.4
+## 飞行时用哪几层做落地判定。玩家投掷时会把它设成玩家自己的 collision_mask，
+## 所以"钥匙能落在哪"严格等于"玩家能站在哪"。
+@export var flight_mask: int = 1
+
+var state: State = State.IDLE
+var velocity := Vector2.ZERO
+
+var _settle := 0.0
+
+
+func _ready() -> void:
+	body_entered.connect(_on_body_entered)
+	if erase_placeholder_on_ready:
+		_erase_placeholder_tile()
+	_start_idle()
+
+
+func _physics_process(_delta: float) -> void:
+	if state == State.LANDED:
+		_settle += STEP
+		if _settle >= settle_time:
+			_start_idle()
+		return
+	if state != State.THROWN:
+		return
+
+	var g := gravity()
+	var motion := velocity * STEP
+	var from := global_position + Vector2(0.0, FOOT_OFFSET)
+	var query := PhysicsRayQueryParameters2D.create(from, from + motion, flight_mask)
+	var hit := get_world_2d().direct_space_state.intersect_ray(query)
+	if hit.is_empty():
+		global_position += motion
+		velocity.y += g * STEP
+	else:
+		global_position = hit["position"] - Vector2(0.0, FOOT_OFFSET)
+		velocity = Vector2.ZERO
+		state = State.LANDED
+		_settle = 0.0
+
+
+# ---------------------------------------------------------------- 对外接口
+
+func launch(v: Vector2) -> void:
+	velocity = v
+	state = State.THROWN
+	monitoring = false
+	_settle = 0.0
+
+
+func _start_idle() -> void:
+	state = State.IDLE
+	velocity = Vector2.ZERO
+	monitoring = true
+
+
+func _on_body_entered(body: Node2D) -> void:
+	if state != State.IDLE:
+		return
+	if body.has_method("collect_key"):
+		body.collect_key()
+		collected.emit()
+		queue_free()
+
+
+# ---------------------------------------------------------------- 轨迹模拟
+
+static func gravity() -> float:
+	return float(ProjectSettings.get_setting("physics/2d/default_gravity", 980.0))
+
+
+## 和 _physics_process 里的推进方式完全一致，玩家用它来画预览弧线，
+## 所以预览落点和真正落点会重合。mask 就是玩家的碰撞掩码。
+static func simulate_trajectory(
+		space: PhysicsDirectSpaceState2D,
+		start: Vector2,
+		vel: Vector2,
+		mask: int,
+		max_steps: int = MAX_STEPS) -> Dictionary:
+	var points := PackedVector2Array()
+	var p := start
+	var v := vel
+	var g := gravity()
+	points.append(p)
+	for i in max_steps:
+		var next := p + v * STEP
+		var query := PhysicsRayQueryParameters2D.create(
+				p + Vector2(0.0, FOOT_OFFSET), next + Vector2(0.0, FOOT_OFFSET), mask)
+		var hit := space.intersect_ray(query)
+		if not hit.is_empty():
+			var landing: Vector2 = hit["position"] - Vector2(0.0, FOOT_OFFSET)
+			points.append(landing)
+			return {"points": points, "landed": true, "landing": landing}
+		p = next
+		v.y += g * STEP
+		points.append(p)
+	return {"points": points, "landed": false, "landing": p}
+
+
+# ---------------------------------------------------------------- 清理占位地砖
+
+func _erase_placeholder_tile() -> void:
+	var root: Node = owner if owner != null else get_parent()
+	if root == null:
+		return
+	for layer in root.find_children("*", "TileMapLayer", true, false):
+		var cell: Vector2i = layer.local_to_map(layer.to_local(global_position))
+		if layer.get_cell_source_id(cell) != -1:
+			layer.erase_cell(cell)

scripts/key.gd.uid

@@ -0,0 +1 @@
+uid://bx5nwb3eghex7

scripts/player_controller.gd

@@ -0,0 +1,405 @@
+extends CharacterBody2D
+
+signal died
+
+const KEY_SCENE := preload("res://scenes/prefabs/collectibles/key_gold.tscn")
+const KEY_SCRIPT := preload("res://scripts/key.gd")
+const KEY_ATLAS := preload("res://assets/game/tilesets/kenney_tiles_atlas.png")
+const KEY_REGION := Rect2(126, 18, 18, 18)
+
+@export_category("移动参数")
+@export var move_speed: float = 75.0
+@export var acceleration: float = 600.0
+@export var deceleration: float = 800.0
+@export var jump_velocity: float = -190.0
+
+@export_category("生命值")
+## 最大生命值（几颗心）
+@export var max_health: int = 3
+## 按 Z 用掉一个回血道具后，获得的无敌盾持续时间（秒）
+@export var shield_time: float = 5.0
+## 受伤后的无敌时间，避免站在尖刺上反复触发
+@export var invulnerable_time: float = 1.0
+## 受伤瞬间的染色
+@export var hurt_tint: Color = Color(1.0, 0.35, 0.35)
+@export var hurt_flash_time: float = 0.25
+## 有护盾时的染色
+@export var shield_tint: Color = Color(0.6, 0.95, 1.0, 1.0)
+## 死亡后的染色
+@export var dead_tint: Color = Color(0.85, 0.3, 0.3, 1.0)
+
+@export_category("钥匙投掷")
+## 投掷初速度大小
+@export var throw_speed: float = 300.0
+## 投掷仰角（度）
+@export_range(0.0, 89.0, 1.0) var throw_angle_deg: float = 60.0
+## 预测弧线颜色
+@export var arc_color: Color = Color(1.0, 0.94, 0.45, 0.85)
+@export var arc_width: float = 1.5
+## 拿着钥匙时头顶显示一个小图标（不想显示就关掉）
+@export var show_carried_key: bool = true
+
+@export_category("测试用飞行")
+## 开发期测试用：按 F 切换飞行，方便飞到各处查看碰撞效果。
+## 只在编辑器 / 调试版里生效；导出的正式版里按键无效，不会影响平衡。
+@export var debug_fly: bool = true
+@export var fly_speed: float = 90.0
+## 飞行时的角色染色，用来一眼看出飞行开着（不想染色就改成白色）
+@export var fly_tint: Color = Color(0.65, 0.9, 1.0)
+
+
+@onready var sprite: Sprite2D = $Sprite2D
+@onready var collider: CollisionShape2D = $CollisionShape2D
+
+var flying: bool = false
+var facing: int = 1
+var held_key: bool = false
+var is_aiming: bool = false
+var hurt_count: int = 0
+## 当前生命值（几颗心）
+var health: int = 3
+## 身上的回血道具数量（捡到的小球）
+var heal_items: int = 0
+## 无敌盾剩余时间，给 HUD 显示用
+var shield_left: float = 0.0
+## 生命值归零后进入死亡状态：不能操作，交给死亡界面
+var is_dead: bool = false
+
+var _arc: Line2D = null
+var _landing_marker: Polygon2D = null
+var _carried_icon: Sprite2D = null
+## 最近一次扔出去、还没被回收的钥匙
+var _thrown_key: Node = null
+## 角色原点到底部的距离，传送时用来对齐脚底
+var _feet_offset: float = 10.5
+## 出生点，受伤后回到这里
+var _spawn_point := Vector2.ZERO
+var _invulnerable: float = 0.0
+var _hurt_flash: float = 0.0
+
+
+func _ready() -> void:
+	add_to_group("player")
+	_build_throw_visuals()
+	_measure_feet_offset()
+	_spawn_point = global_position
+	health = max_health
+
+
+func _physics_process(delta: float) -> void:
+	if _invulnerable > 0.0:
+		_invulnerable -= delta
+	if _hurt_flash > 0.0:
+		_hurt_flash -= delta
+	if shield_left > 0.0:
+		shield_left -= delta
+
+	if is_dead:
+		# 死亡后不接受任何操作，只让重力把人放下来
+		apply_gravity(delta)
+		velocity.x = move_toward(velocity.x, 0.0, deceleration * delta)
+		_update_tint()
+		move_and_slide()
+		return
+
+	# 正式版里不允许飞行；即使 toggle 开着也强制落回地面
+	if flying and not fly_available():
+		set_flying(false)
+
+	if flying:
+		handle_fly_movement()
+	else:
+		apply_gravity(delta)
+		handle_jump()
+		handle_horizontal_movement(delta)
+
+	update_sprite_direction()
+	_update_tint()
+	if is_aiming:
+		update_arc()
+	move_and_slide()
+
+
+func _unhandled_input(event: InputEvent) -> void:
+	if is_dead:
+		return
+
+	if fly_available() and event.is_action_pressed("fly") and not event.is_echo():
+		set_flying(not flying)
+		return
+
+	if event.is_action_pressed("use_heal") and not event.is_echo():
+		use_heal_item()
+		return
+
+	if event.is_action_pressed("warp_to_key") and not event.is_echo():
+		warp_to_thrown_key()
+		return
+
+	if event.is_action_pressed("squat") and not event.is_echo():
+		if can_aim():
+			is_aiming = true
+			update_arc()
+	elif event.is_action_released("squat"):
+		if is_aiming:
+			release_throw()
+
+
+# ---------------------------------------------------------------- 生命值
+
+## 由尖刺之类的危险物调用
+func hurt(_amount: int = 1) -> void:
+	if is_dead or _invulnerable > 0.0:
+		return
+	hurt_count += 1
+	health -= 1
+	_invulnerable = invulnerable_time
+	_hurt_flash = hurt_flash_time
+	if health <= 0:
+		health = 0
+		_die()
+		return
+	# 没死：打回出生点
+	global_position = _spawn_point
+	velocity = Vector2.ZERO
+	if flying:
+		set_flying(false)
+	if is_aiming:
+		_cancel_aim()
+
+
+func _die() -> void:
+	is_dead = true
+	velocity = Vector2.ZERO
+	if flying:
+		set_flying(false)
+	if is_aiming:
+		_cancel_aim()
+	died.emit()
+
+
+## 由可收集物调用
+func add_heal_item() -> void:
+	heal_items += 1
+
+
+## 按 Z：消耗一个回血道具，回一颗心并获得无敌盾
+func use_heal_item() -> bool:
+	if is_dead or heal_items <= 0:
+		return false
+	heal_items -= 1
+	health = mini(health + 1, max_health)
+	_invulnerable = maxf(_invulnerable, shield_time)
+	shield_left = shield_time
+	return true
+
+
+func _update_tint() -> void:
+	if is_dead:
+		sprite.modulate = dead_tint
+	elif _hurt_flash > 0.0:
+		sprite.modulate = hurt_tint
+	elif shield_left > 0.0:
+		sprite.modulate = shield_tint
+	elif flying:
+		sprite.modulate = fly_tint
+	else:
+		sprite.modulate = Color.WHITE
+
+
+# ---------------------------------------------------------------- 钥匙投掷
+
+func can_aim() -> bool:
+	return held_key and not flying and not is_aiming
+
+
+## 由钥匙对象在碰到玩家时调用
+func collect_key() -> void:
+	held_key = true
+	_update_carried_icon()
+
+
+func throw_velocity() -> Vector2:
+	var rad := deg_to_rad(throw_angle_deg)
+	return Vector2(facing * throw_speed * cos(rad), -throw_speed * sin(rad))
+
+
+func update_arc() -> void:
+	if not is_aiming or _arc == null:
+		return
+	# 用玩家自己的 collision_mask 做预测，所以"弧线能落到的地方"就是"玩家能站的地方"
+	var result := KEY_SCRIPT.simulate_trajectory(
+			get_world_2d().direct_space_state,
+			global_position,
+			throw_velocity(),
+			collision_mask)
+	_arc.points = result["points"]
+	_arc.visible = _arc.points.size() > 1
+	var landed: bool = result["landed"]
+	if _landing_marker != null:
+		_landing_marker.visible = landed
+		if landed:
+			_landing_marker.global_position = result["landing"]
+
+
+func release_throw() -> void:
+	is_aiming = false
+	_hide_throw_visuals()
+	if not held_key:
+		return
+
+	held_key = false
+	_update_carried_icon()
+
+	var key: Node = KEY_SCENE.instantiate()
+	# 这是玩家扔出去的钥匙，不要去擦关卡里的占位地砖
+	key.erase_placeholder_on_ready = false
+	# 让钥匙的落地判定和玩家完全一致
+	key.flight_mask = collision_mask
+	get_parent().add_child(key)
+	key.global_position = global_position
+	key.launch(throw_velocity())
+	_thrown_key = key
+
+
+## 按 W：传送到扔出去的那把钥匙所在的位置，并顺手把它捡回来
+func warp_to_thrown_key() -> void:
+	if _thrown_key == null or not is_instance_valid(_thrown_key):
+		return
+
+	var key_pos: Vector2 = _thrown_key.global_position
+	# 让玩家的脚底落在钥匙脚底所在的那个面上，避免直接嵌进地形
+	global_position = Vector2(key_pos.x, key_pos.y + KEY_SCRIPT.FOOT_OFFSET - _feet_offset)
+	velocity = Vector2.ZERO
+
+	if is_aiming:
+		_cancel_aim()
+
+	_thrown_key.queue_free()
+	_thrown_key = null
+	held_key = true
+	_update_carried_icon()
+
+
+func _cancel_aim() -> void:
+	is_aiming = false
+	_hide_throw_visuals()
+
+
+func _hide_throw_visuals() -> void:
+	if _arc != null:
+		_arc.visible = false
+	if _landing_marker != null:
+		_landing_marker.visible = false
+
+
+func _update_carried_icon() -> void:
+	if _carried_icon != null:
+		_carried_icon.visible = held_key
+
+
+func _measure_feet_offset() -> void:
+	if collider == null or collider.shape == null:
+		return
+	var shape := collider.shape
+	if shape is CapsuleShape2D:
+		_feet_offset = collider.position.y + shape.height * 0.5
+	elif shape is RectangleShape2D:
+		_feet_offset = collider.position.y + shape.size.y * 0.5
+	elif shape is CircleShape2D:
+		_feet_offset = collider.position.y + shape.radius
+
+
+func _build_throw_visuals() -> void:
+	# top_level = true 让它们忽略角色自身那个 rotation/scale 翻转，直接用世界坐标
+	_arc = Line2D.new()
+	_arc.width = arc_width
+	_arc.default_color = arc_color
+	_arc.visible = false
+	add_child(_arc)
+	_arc.top_level = true
+
+	_landing_marker = Polygon2D.new()
+	var s := 4.0
+	_landing_marker.polygon = PackedVector2Array([
+			Vector2(0.0, -s), Vector2(s, 0.0), Vector2(0.0, s), Vector2(-s, 0.0)])
+	_landing_marker.color = arc_color
+	_landing_marker.visible = false
+	add_child(_landing_marker)
+	_landing_marker.top_level = true
+
+	if show_carried_key:
+		var tex := AtlasTexture.new()
+		tex.atlas = KEY_ATLAS
+		tex.region = KEY_REGION
+		_carried_icon = Sprite2D.new()
+		_carried_icon.texture = tex
+		_carried_icon.texture_filter = CanvasItem.TEXTURE_FILTER_NEAREST
+		_carried_icon.position = Vector2(0.0, -15.0)
+		_carried_icon.visible = false
+		add_child(_carried_icon)
+
+
+# ---------------------------------------------------------------- 测试用飞行
+
+func fly_available() -> bool:
+	return debug_fly and OS.is_debug_build()
+
+
+func set_flying(on: bool) -> void:
+	flying = on
+	velocity = Vector2.ZERO
+	if on:
+		_cancel_aim()
+
+
+func handle_fly_movement() -> void:
+	# get_axis(负方向, 正方向)，屏幕坐标里 y 向下为正，所以空格(跳跃)要放在负方向
+	var direction := Vector2(
+			Input.get_axis("move_left", "move_right"),
+			Input.get_axis("jump", "squat")
+	)
+	if direction == Vector2.ZERO:
+		velocity = Vector2.ZERO
+	else:
+		velocity = direction.normalized() * fly_speed
+
+
+# ---------------------------------------------------------------- 正常移动
+
+func apply_gravity(delta: float) -> void:
+	if not is_on_floor():
+		velocity += get_gravity() * delta
+
+
+func handle_horizontal_movement(delta: float) -> void:
+	var direction := Input.get_axis("move_left", "move_right")
+	var target_speed := direction * move_speed
+
+	if direction != 0.0:
+		velocity.x = move_toward(
+				velocity.x,
+				target_speed,
+				acceleration * delta
+		)
+	else:
+		velocity.x = move_toward(
+				velocity.x,
+				0.0,
+				deceleration * delta
+		)
+
+
+func handle_jump() -> void:
+	# 只有踩在地面上才能起跳 —— 空中不再给第二次机会，不做多段跳
+	if Input.is_action_just_pressed("jump") and is_on_floor():
+		velocity.y = jump_velocity
+
+
+func update_sprite_direction() -> void:
+	if velocity.x > 0.0:
+		facing = 1
+		sprite.flip_h = false
+	elif velocity.x < 0.0:
+		facing = -1
+		sprite.flip_h = true

scripts/player_controller.gd.uid

@@ -0,0 +1 @@
+uid://b0gltif7vthau

scripts/spring.gd

@@ -0,0 +1,23 @@
+extends Area2D
+
+## 弹起角色时给它的向上速度（负值 = 向上）。玩家正常跳跃是 -190，这里给约 1.6 倍。
+@export var bounce_velocity: float = -300.0
+## 角色的竖直速度要 >= 这个值才弹（正在往上冲的时候不弹，免得把人往下拍）
+@export var min_downward_speed: float = -1.0
+## 角色的中心必须比弹簧中心高出这么多像素，才算"从上面踩下来"；从侧面撞过去不弹
+@export var top_zone_offset: float = 4.0
+
+
+func _ready() -> void:
+	body_entered.connect(_on_body_entered)
+
+
+func _on_body_entered(body: Node2D) -> void:
+	var character := body as CharacterBody2D
+	if character == null:
+		return
+	if character.velocity.y < min_downward_speed:
+		return
+	if character.global_position.y > global_position.y - top_zone_offset:
+		return
+	character.velocity.y = bounce_velocity

scripts/spring.gd.uid

@@ -0,0 +1 @@
+uid://bc10ax0n3w2sp