Extracted ball collection particle lagic into HUDParticle type

assets/sprites/particles/ball.png.import

@@ -0,0 +1,34 @@
+[remap]
+
+importer="texture"
+type="CompressedTexture2D"
+uid="uid://dtsdecae83ah3"
+path="res://.godot/imported/ball.png-9141da4d584001e11280d9c246b59589.ctex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://assets/sprites/particles/ball.png"
+dest_files=["res://.godot/imported/ball.png-9141da4d584001e11280d9c246b59589.ctex"]
+
+[params]
+
+compress/mode=0
+compress/high_quality=false
+compress/lossy_quality=0.7
+compress/hdr_compression=1
+compress/normal_map=0
+compress/channel_pack=0
+mipmaps/generate=true
+mipmaps/limit=-1
+roughness/mode=0
+roughness/src_normal=""
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/normal_map_invert_y=false
+process/hdr_as_srgb=false
+process/hdr_clamp_exposure=false
+process/size_limit=0
+detect_3d/compress_to=1

src/items/extra_ball/extra_ball.gd

@@ -13,4 +13,4 @@ func _collect(player: WorldPlayer) -> void:
 		player.mutate_balls(ball_type, amount)
 
 	player.shot_setup.hud.peek_club_selector()
-	player.shot_setup.hud.emit_ball_particles(maxi(amount, 1), screen_location())
+	player.shot_setup.hud.ball_particles.emit_spatial(maxi(amount, 1), global_position)

src/items/item/item.gd

@@ -10,14 +10,6 @@ signal on_collect(player: WorldPlayer)
 @onready var explosion_player: AnimationPlayer = %ExplosionPlayer
 
 
-## Relative location of this item in screen coordinates.
-## Useful for particle effects
-func screen_location() -> Vector2:
-	var location := get_viewport().get_camera_3d().unproject_position(global_position)
-	# TODO: what if this is off-screen?
-	return location
-
-
 func collect(player: WorldPlayer) -> void:
 	# Note that this animation will call `queue_free` in 5 seconds!
 	explosion_player.play("explode")

src/ui/decorations/hud_particles/hud_particles.gd

@@ -0,0 +1,22 @@
+class_name HUDParticles extends GPUParticles2D
+## 2D particle emitter with spatial logic, for emitting particles in the HUD.
+
+
+## Emit the given number of particles in one shot.
+func emit(_amount: int) -> void:
+	amount = _amount
+	emitting = true
+
+
+## Emit the given number of particles from the given screen location.
+func emit_at_location(_amount: int, source_location: Vector2) -> void:
+	var particle_mat: ParticleProcessMaterial = process_material
+	particle_mat.emission_shape_offset = Vector3(source_location.x, source_location.y, 0)
+	emit(_amount)
+
+
+## Emit the given number of particles from the screen location of the given point in 3D space.
+func emit_spatial(_amount: int, source_location: Vector3) -> void:
+	var screen_location := get_viewport().get_camera_3d().unproject_position(source_location)
+	# TODO: what to do if this is outside the viewport?
+	emit_at_location(_amount, screen_location)

src/ui/decorations/hud_particles/hud_particles.tscn

@@ -0,0 +1,50 @@
+[gd_scene load_steps=9 format=3 uid="uid://dfh0bv7lwewj5"]
+
+[ext_resource type="Script" path="res://src/ui/decorations/hud_particles/hud_particles.gd" id="1_leh7k"]
+
+[sub_resource type="Curve" id="Curve_mp3bg"]
+max_value = 100.0
+_data = [Vector2(0.0431211, 0), 0.0, 21.2919, 0, 0, Vector2(1, 100), 336.968, 0.0, 0, 0]
+point_count = 2
+
+[sub_resource type="CurveTexture" id="CurveTexture_satut"]
+curve = SubResource("Curve_mp3bg")
+
+[sub_resource type="Curve" id="Curve_a5ydw"]
+max_value = 200.0
+_data = [Vector2(0, 9.02831), 0.0, 0.618766, 0, 0, Vector2(1, 200), 450.985, 0.0, 0, 0]
+point_count = 2
+
+[sub_resource type="CurveTexture" id="CurveTexture_oynpa"]
+curve = SubResource("Curve_a5ydw")
+
+[sub_resource type="Curve" id="Curve_53gso"]
+_data = [Vector2(0, 0), 0.0, 0.0, 0, 0, Vector2(0.0616016, 1), 0.0, 0.0, 0, 0, Vector2(0.761807, 1), 0.0, 0.0, 0, 0, Vector2(1, 0), 0.0, 0.0, 0, 0]
+point_count = 4
+
+[sub_resource type="CurveTexture" id="CurveTexture_a05qh"]
+curve = SubResource("Curve_53gso")
+
+[sub_resource type="ParticleProcessMaterial" id="ParticleProcessMaterial_besmx"]
+particle_flag_disable_z = true
+direction = Vector3(0, 0, 0)
+spread = 180.0
+initial_velocity_min = 400.0
+initial_velocity_max = 600.0
+gravity = Vector3(0, 0, 0)
+radial_accel_min = -100.0
+radial_accel_max = -100.0
+radial_accel_curve = SubResource("CurveTexture_oynpa")
+damping_min = 200.0
+damping_max = 200.0
+damping_curve = SubResource("CurveTexture_satut")
+scale_curve = SubResource("CurveTexture_a05qh")
+
+[node name="HUDParticles" type="GPUParticles2D"]
+emitting = false
+amount = 32
+process_material = SubResource("ParticleProcessMaterial_besmx")
+lifetime = 1.4
+one_shot = true
+explosiveness = 0.7
+script = ExtResource("1_leh7k")

src/ui/shot_hud/shot_hud.gd

@@ -16,7 +16,7 @@ var player: WorldPlayer
 
 @onready var club_selector: ClubSelector = %ClubSelector
 @onready var ball_selector: BallSelector = %BallSelector
-@onready var _ball_particles: GPUParticles2D = %BallParticles
+@onready var ball_particles: HUDParticles = %BallParticles
 
 @onready var _curve_animation: AnimationPlayer = %CurveAnimation
 @onready var _power_animation: AnimationPlayer = %PowerAnimation
@@ -110,13 +110,6 @@ func hide_reset_prompt() -> void:
 	_reset_prompt_animation.play_backwards("show")
 
 
-func emit_ball_particles(amount: int, location: Vector2) -> void:
-	var particle_mat: ParticleProcessMaterial = _ball_particles.process_material
-	particle_mat.emission_shape_offset = Vector3(location.x, location.y, 0)
-	_ball_particles.amount = amount
-	_ball_particles.emitting = true
-
-
 ## Set the value of the life bar, potentially playing some kind of effect in response.
 ##
 ## To set the life bar without triggering an effect, set it directly with `life_bar.value`

src/ui/shot_hud/shot_hud.tscn

@@ -1,4 +1,4 @@
-[gd_scene load_steps=49 format=3 uid="uid://c4ifdiohng830"]
+[gd_scene load_steps=44 format=3 uid="uid://c4ifdiohng830"]
 
 [ext_resource type="Script" path="res://src/ui/shot_hud/shot_hud.gd" id="1_x5b4c"]
 [ext_resource type="Shader" path="res://src/shaders/canvas_retro.gdshader" id="1_ybxxp"]
@@ -12,6 +12,8 @@
 [ext_resource type="FontFile" uid="uid://dsa0oh7c0h4pu" path="res://assets/fonts/Racing_Sans_One/RacingSansOne-Regular.ttf" id="8_bejx4"]
 [ext_resource type="Texture2D" uid="uid://tancoet1lih5" path="res://assets/ui/ball_icons/basic_icon.png" id="8_tt8i3"]
 [ext_resource type="PackedScene" uid="uid://dmciuk3pbjsae" path="res://src/ui/shot_hud/life_bar/life_bar.tscn" id="9_w1fiw"]
+[ext_resource type="PackedScene" uid="uid://dfh0bv7lwewj5" path="res://src/ui/decorations/hud_particles/hud_particles.tscn" id="11_ie5ih"]
+[ext_resource type="Texture2D" uid="uid://dtsdecae83ah3" path="res://assets/sprites/particles/ball.png" id="12_fdbqt"]
 [ext_resource type="PackedScene" uid="uid://b47goj32i6sdh" path="res://src/ui/elements/input_prompt/input_prompt.tscn" id="14_ik4gg"]
 
 [sub_resource type="Animation" id="Animation_2gt87"]
@@ -324,51 +326,6 @@ _data = {
 "show": SubResource("Animation_x6kyr")
 }
 
-[sub_resource type="Curve" id="Curve_mp3bg"]
-max_value = 100.0
-_data = [Vector2(0.0431211, 0), 0.0, 21.2919, 0, 0, Vector2(1, 100), 336.968, 0.0, 0, 0]
-point_count = 2
-
-[sub_resource type="CurveTexture" id="CurveTexture_satut"]
-curve = SubResource("Curve_mp3bg")
-
-[sub_resource type="Curve" id="Curve_a5ydw"]
-max_value = 200.0
-_data = [Vector2(0, 9.02831), 0.0, 0.618766, 0, 0, Vector2(1, 200), 450.985, 0.0, 0, 0]
-point_count = 2
-
-[sub_resource type="CurveTexture" id="CurveTexture_oynpa"]
-curve = SubResource("Curve_a5ydw")
-
-[sub_resource type="Curve" id="Curve_53gso"]
-_data = [Vector2(0, 0), 0.0, 0.0, 0, 0, Vector2(0.0616016, 1), 0.0, 0.0, 0, 0, Vector2(0.761807, 1), 0.0, 0.0, 0, 0, Vector2(1, 0), 0.0, 0.0, 0, 0]
-point_count = 4
-
-[sub_resource type="CurveTexture" id="CurveTexture_a05qh"]
-curve = SubResource("Curve_53gso")
-
-[sub_resource type="ParticleProcessMaterial" id="ParticleProcessMaterial_besmx"]
-particle_flag_disable_z = true
-emission_shape_offset = Vector3(800, 600, 0)
-angle_min = -720.0
-angle_max = 720.0
-direction = Vector3(0, 0, 0)
-spread = 180.0
-initial_velocity_min = 400.0
-initial_velocity_max = 600.0
-angular_velocity_min = -100.0
-angular_velocity_max = 100.0
-gravity = Vector3(0, 0, 0)
-radial_accel_min = -100.0
-radial_accel_max = -100.0
-radial_accel_curve = SubResource("CurveTexture_oynpa")
-damping_min = 200.0
-damping_max = 200.0
-damping_curve = SubResource("CurveTexture_satut")
-scale_min = 0.4
-scale_max = 0.4
-scale_curve = SubResource("CurveTexture_a05qh")
-
 [sub_resource type="Animation" id="Animation_3cn2c"]
 resource_name = "RESET"
 length = 0.001
@@ -787,15 +744,9 @@ anchor_bottom = 0.5
 grow_horizontal = 2
 grow_vertical = 2
 
-[node name="BallParticles" type="GPUParticles2D" parent="ClubSelector/TextureRect/BallParticleContainer"]
+[node name="BallParticles" parent="ClubSelector/TextureRect/BallParticleContainer" instance=ExtResource("11_ie5ih")]
 unique_name_in_owner = true
-emitting = false
-amount = 32
-process_material = SubResource("ParticleProcessMaterial_besmx")
-texture = ExtResource("8_tt8i3")
-lifetime = 1.4
-one_shot = true
-explosiveness = 0.7
+texture = ExtResource("12_fdbqt")
 
 [node name="SouthWest" type="MarginContainer" parent="."]
 layout_mode = 1