feat(子弹): 为弓箭子弹添加蓄力效果和粒子特效

添加蓄力等待时间和粒子特效系统，使弓箭在发射前有蓄力效果，并在发射时显示火焰粒子特效。修改了Bow.gd和Arrow.gd以支持蓄力时间参数，并更新Arrow.tscn添加新的粒子系统节点。

components/Bullets/Arrow.tscn

@@ -1,4 +1,4 @@
-[gd_scene load_steps=8 format=3 uid="uid://wy8wqwhwr4fb"]
+[gd_scene load_steps=13 format=3 uid="uid://wy8wqwhwr4fb"]
 
 [ext_resource type="PackedScene" uid="uid://crtdkysmnkith" path="res://components/Abstracts/BulletBase.tscn" id="1_0wuio"]
 [ext_resource type="Texture2D" uid="uid://dadbn306owsy3" path="res://resources/bullets/arrow/arrow.png" id="2_b2ohg"]
@@ -20,6 +20,32 @@ initial_velocity_max = 3000.0
 gravity = Vector3(0, 0, 0)
 alpha_curve = SubResource("CurveTexture_cawe8")
 
+[sub_resource type="Curve" id="Curve_qddg0"]
+_data = [Vector2(0, 1), 0.0, 0.0, 0, 0, Vector2(1, 0), 0.0, 0.0, 0, 0]
+point_count = 2
+
+[sub_resource type="CurveTexture" id="CurveTexture_uu3a4"]
+curve = SubResource("Curve_qddg0")
+
+[sub_resource type="Gradient" id="Gradient_cawe8"]
+colors = PackedColorArray(1, 0, 0, 1, 1, 0.8159592, 0, 1)
+
+[sub_resource type="GradientTexture1D" id="GradientTexture1D_afwvr"]
+gradient = SubResource("Gradient_cawe8")
+
+[sub_resource type="ParticleProcessMaterial" id="ParticleProcessMaterial_qddg0"]
+particle_flag_disable_z = true
+emission_shape = 1
+emission_sphere_radius = 150.0
+direction = Vector3(-1, 0, 0)
+spread = 20.0
+initial_velocity_max = 2500.0
+gravity = Vector3(0, 0, 0)
+scale_min = 20.0
+scale_max = 60.0
+color_initial_ramp = SubResource("GradientTexture1D_afwvr")
+alpha_curve = SubResource("CurveTexture_uu3a4")
+
 [sub_resource type="CircleShape2D" id="CircleShape2D_b2ohg"]
 
 [node name="Arrow" instance=ExtResource("1_0wuio")]
@@ -35,6 +61,7 @@ scale = Vector2(0.06775362, 0.06775362)
 texture = ExtResource("2_b2ohg")
 
 [node name="trail" type="GPUParticles2D" parent="texture/static" index="0"]
+unique_name_in_owner = true
 z_index = -1
 amount = 12
 texture = ExtResource("2_b2ohg")
@@ -42,6 +69,13 @@ preprocess = 1.0
 local_coords = true
 process_material = SubResource("ParticleProcessMaterial_afwvr")
 
+[node name="fire" type="GPUParticles2D" parent="texture/static" index="1"]
+position = Vector2(1328.3423, 44.278076)
+amount = 300
+preprocess = 1.0
+local_coords = true
+process_material = SubResource("ParticleProcessMaterial_qddg0")
+
 [node name="hitbox" parent="." index="1"]
 position = Vector2(85, 0)
 shape = SubResource("CircleShape2D_b2ohg")

scripts/Contents/Bullets/Arrow.gd

@@ -1,9 +1,23 @@
 extends BulletBase
 class_name Arrow
 
-var atk: float = 0
+@onready var trail: GPUParticles2D = $%trail
 
+var atk: float = 0
+var waitTime: float = 0
+
+func register():
+	trail.emitting = false
+	hitbox.disabled = true
 func ai():
+	if timeLived() < waitTime:
+		PresetBulletAI.lockLauncher(self, launcher, true)
+		rotation = position.angle_to_point(get_global_mouse_position())
+		position += Vector2.from_angle(rotation) * 200
+		return
+	else:
+		trail.emitting = true
+		hitbox.disabled = false
 	speed = (1 - lifeDistancePercent()) * initialSpeed
 	damage = speed * atk
 	PresetBulletAI.forward(self, rotation)

scripts/Contents/Bullets/Bow.gd

@@ -3,9 +3,9 @@ class_name Bow
 
 var count: int = 0
 var atk: float = 0
+var waitTime: float = 1000
 
 func spawn():
-	await TickTool.millseconds(1000)
 	var startAngle = rotation - deg_to_rad(count * 10.0 / 2)
 	for c in count:
 		for i in BulletBase.generate(
@@ -16,6 +16,8 @@ func spawn():
 		):
 			var bullet: Arrow = i
 			bullet.atk = atk
+			bullet.waitTime = waitTime
+	await TickTool.millseconds(waitTime)
 	tryDestroy()
 func ai():
 	PresetBulletAI.lockLauncher(self, launcher, true)