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).
2026-10-07 20:32:42 +08:00
commit 9dffacd938
558 changed files with 12258 additions and 0 deletions
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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)