The dreaded screenshaker!

src/game/game.gd

@@ -5,6 +5,8 @@ class_name Game extends Node
 
 var _loading_resources := {}
 
+@onready var viewport: GameViewportContainer = %ViewportContainer
+
 @onready var content: Node = %Content
 @onready var loader_transition: AnimationPlayer = %LoaderTransition
 @onready var loading_screen: Control = %LoadingScreen

src/game/game.tscn

@@ -1,7 +1,35 @@
-[gd_scene load_steps=7 format=3 uid="uid://cefit4bc8akbb"]
+[gd_scene load_steps=8 format=3 uid="uid://cefit4bc8akbb"]
 
 [ext_resource type="Script" path="res://src/game/game.gd" id="1_4qa87"]
 [ext_resource type="FontFile" uid="uid://dsa0oh7c0h4pu" path="res://assets/fonts/Racing_Sans_One/RacingSansOne-Regular.ttf" id="2_y3adf"]
+[ext_resource type="Script" path="res://src/ui/game_viewport_container.gd" id="3_rmm5i"]
+
+[sub_resource type="Animation" id="Animation_c3dlb"]
+length = 0.001
+tracks/0/type = "value"
+tracks/0/imported = false
+tracks/0/enabled = true
+tracks/0/path = NodePath(".:visible")
+tracks/0/interp = 1
+tracks/0/loop_wrap = true
+tracks/0/keys = {
+"times": PackedFloat32Array(0),
+"transitions": PackedFloat32Array(1),
+"update": 1,
+"values": [true]
+}
+tracks/1/type = "value"
+tracks/1/imported = false
+tracks/1/enabled = true
+tracks/1/path = NodePath(".:modulate")
+tracks/1/interp = 1
+tracks/1/loop_wrap = true
+tracks/1/keys = {
+"times": PackedFloat32Array(0),
+"transitions": PackedFloat32Array(1),
+"update": 0,
+"values": [Color(1, 1, 1, 1)]
+}
 
 [sub_resource type="Animation" id="Animation_2c1ud"]
 resource_name = "fade_in"
@@ -31,33 +59,6 @@ tracks/1/keys = {
 "values": [Color(1, 1, 1, 0), Color(1, 1, 1, 1)]
 }
 
-[sub_resource type="Animation" id="Animation_c3dlb"]
-length = 0.001
-tracks/0/type = "value"
-tracks/0/imported = false
-tracks/0/enabled = true
-tracks/0/path = NodePath(".:visible")
-tracks/0/interp = 1
-tracks/0/loop_wrap = true
-tracks/0/keys = {
-"times": PackedFloat32Array(0),
-"transitions": PackedFloat32Array(1),
-"update": 1,
-"values": [true]
-}
-tracks/1/type = "value"
-tracks/1/imported = false
-tracks/1/enabled = true
-tracks/1/path = NodePath(".:modulate")
-tracks/1/interp = 1
-tracks/1/loop_wrap = true
-tracks/1/keys = {
-"times": PackedFloat32Array(0),
-"transitions": PackedFloat32Array(1),
-"update": 0,
-"values": [Color(1, 1, 1, 1)]
-}
-
 [sub_resource type="Animation" id="Animation_xbqy2"]
 resource_name = "fade_out"
 length = 0.4
@@ -94,9 +95,11 @@ _data = {
 }
 
 [node name="Game" type="Node" groups=["GameGroup"]]
+process_mode = 3
 script = ExtResource("1_4qa87")
 
-[node name="Control" type="Control" parent="."]
+[node name="RootControl" type="Control" parent="."]
+unique_name_in_owner = true
 layout_mode = 3
 anchors_preset = 15
 anchor_right = 1.0
@@ -104,7 +107,7 @@ anchor_bottom = 1.0
 grow_horizontal = 2
 grow_vertical = 2
 
-[node name="LoadingScreen" type="Control" parent="Control"]
+[node name="LoadingScreen" type="Control" parent="RootControl"]
 unique_name_in_owner = true
 z_index = 128
 layout_mode = 1
@@ -115,7 +118,7 @@ grow_horizontal = 2
 grow_vertical = 2
 mouse_filter = 2
 
-[node name="ColorRect" type="ColorRect" parent="Control/LoadingScreen"]
+[node name="ColorRect" type="ColorRect" parent="RootControl/LoadingScreen"]
 layout_mode = 1
 anchors_preset = 15
 anchor_right = 1.0
@@ -125,7 +128,7 @@ grow_vertical = 2
 mouse_filter = 2
 color = Color(0, 0, 0, 1)
 
-[node name="MarginContainer" type="MarginContainer" parent="Control/LoadingScreen"]
+[node name="MarginContainer" type="MarginContainer" parent="RootControl/LoadingScreen"]
 layout_mode = 1
 anchors_preset = 3
 anchor_left = 1.0
@@ -139,7 +142,7 @@ grow_vertical = 0
 theme_override_constants/margin_right = 64
 theme_override_constants/margin_bottom = 32
 
-[node name="RichTextLabel" type="RichTextLabel" parent="Control/LoadingScreen/MarginContainer"]
+[node name="RichTextLabel" type="RichTextLabel" parent="RootControl/LoadingScreen/MarginContainer"]
 custom_minimum_size = Vector2(160, 0)
 layout_mode = 2
 mouse_filter = 2
@@ -150,13 +153,15 @@ bbcode_enabled = true
 text = "[wave]LOADING...[/wave]"
 fit_content = true
 
-[node name="LoaderTransition" type="AnimationPlayer" parent="Control/LoadingScreen"]
+[node name="LoaderTransition" type="AnimationPlayer" parent="RootControl/LoadingScreen"]
 unique_name_in_owner = true
 libraries = {
 "": SubResource("AnimationLibrary_1s0w0")
 }
 
-[node name="ViewportContainer" type="SubViewportContainer" parent="Control"]
+[node name="ViewportContainer" type="SubViewportContainer" parent="RootControl"]
+unique_name_in_owner = true
+process_mode = 3
 layout_mode = 1
 anchors_preset = 15
 anchor_right = 1.0
@@ -164,8 +169,9 @@ anchor_bottom = 1.0
 grow_horizontal = 2
 grow_vertical = 2
 stretch = true
+script = ExtResource("3_rmm5i")
 
-[node name="Viewport" type="SubViewport" parent="Control/ViewportContainer"]
+[node name="Viewport" type="SubViewport" parent="RootControl/ViewportContainer"]
 handle_input_locally = false
 msaa_2d = 3
 msaa_3d = 3
@@ -174,5 +180,6 @@ use_taa = true
 size = Vector2i(1280, 720)
 render_target_update_mode = 4
 
-[node name="Content" type="Node" parent="Control/ViewportContainer/Viewport"]
+[node name="Content" type="Node" parent="RootControl/ViewportContainer/Viewport"]
 unique_name_in_owner = true
+process_mode = 1

src/ui/game_viewport_container.gd

@@ -0,0 +1,26 @@
+class_name GameViewportContainer extends SubViewportContainer
+## SubViewportContainer with game-specific special effects
+
+var _screen_shake_intensity: float = 0.0
+
+@onready var root_control: Control = %RootControl
+
+
+## Start playing a screen shake effect.
+func screen_shake(intensity: float, duration: float = 0.2) -> void:
+	var tween := get_tree().create_tween()
+	_screen_shake_intensity = intensity
+	tween.tween_property(self, "_screen_shake_intensity", 0.0, duration).set_trans(
+		Tween.TRANS_CUBIC
+	)
+	tween.tween_callback(_reset_position)
+
+
+func _reset_position() -> void:
+	position = Vector2.ZERO
+
+
+func _process(_delta: float) -> void:
+	if _screen_shake_intensity > 0:
+		position.x = randfn(0, _screen_shake_intensity)
+		position.y = randfn(0, _screen_shake_intensity)