refactor the dynamic split screen demo

 - both 2D and 3D scenes have the exact same hierarchy
 - a single camera_controller.gd script instead of one per mode
 - the third viewport for 2D mode has been removed

viewport/dynamic_split_screen/2d/split_screen.tscn

@@ -1,6 +1,6 @@
 [gd_scene load_steps=7 format=2]
 
-[ext_resource path="res://2d/camera_controller.gd" type="Script" id=1]
+[ext_resource path="res://camera_controller.gd" type="Script" id=1]
 [ext_resource path="res://split_screen.shader" type="Shader" id=2]
 [ext_resource path="res://icon.png" type="Texture" id=3]
 [ext_resource path="res://exit_to_menu.gd" type="Script" id=4]
@@ -15,44 +15,39 @@ shader_param/player2_position = null
 shader_param/split_line_thickness = null
 shader_param/split_line_color = null
 
-[node name="Main" type="Node2D"]
+[node name="Game" type="Node2D"]
 script = ExtResource( 4 )
 
-[node name="View" type="TextureRect" parent="."]
+[node name="SplitScreen" type="Node" parent="."]
+script = ExtResource( 1 )
+max_separation = 100.0
+
+[node name="View" type="TextureRect" parent="SplitScreen"]
 material = SubResource( 1 )
 margin_right = 1024.0
 margin_bottom = 600.0
 texture = ExtResource( 3 )
 expand = true
 
-[node name="Cameras" type="Node" parent="."]
-script = ExtResource( 1 )
-max_separation = 100.0
-
-[node name="Viewport1" type="Viewport" parent="Cameras"]
-size = Vector2( 100, 100 )
+[node name="Main" type="Viewport" parent="SplitScreen"]
+size = Vector2( 1024, 600 )
 disable_3d = true
 usage = 0
 render_target_v_flip = true
-render_target_update_mode = 3
 
-[node name="Camera" type="Camera2D" parent="Cameras/Viewport1"]
+[node name="Level" parent="SplitScreen/Main" instance=ExtResource( 5 )]
+
+[node name="Camera" type="Camera2D" parent="SplitScreen/Main"]
 current = true
 zoom = Vector2( 0.2, 0.2 )
 
-[node name="Viewport2" type="Viewport" parent="Cameras"]
+[node name="Secondary" type="Viewport" parent="SplitScreen"]
 size = Vector2( 100, 100 )
+disable_3d = true
 usage = 0
 render_target_v_flip = true
 render_target_update_mode = 3
 
-[node name="Camera" type="Camera2D" parent="Cameras/Viewport2"]
+[node name="Camera" type="Camera2D" parent="SplitScreen/Secondary"]
 current = true
 zoom = Vector2( 0.2, 0.2 )
-
-[node name="Game" type="Viewport" parent="."]
-size = Vector2( 1024, 600 )
-disable_3d = true
-usage = 0
-
-[node name="Level" parent="Game" instance=ExtResource( 5 )]

viewport/dynamic_split_screen/3d/split_screen.tscn

@@ -1,7 +1,7 @@
 [gd_scene load_steps=7 format=2]
 
 [ext_resource path="res://3d/level.tscn" type="PackedScene" id=1]
-[ext_resource path="res://3d/camera_controller.gd" type="Script" id=2]
+[ext_resource path="res://camera_controller.gd" type="Script" id=2]
 [ext_resource path="res://split_screen.shader" type="Shader" id=3]
 [ext_resource path="res://icon.png" type="Texture" id=4]
 [ext_resource path="res://exit_to_menu.gd" type="Script" id=6]
@@ -15,39 +15,39 @@ shader_param/player2_position = null
 shader_param/split_line_thickness = null
 shader_param/split_line_color = null
 
-[node name="Main" type="Spatial"]
+[node name="Game" type="Spatial"]
 script = ExtResource( 6 )
 
-[node name="View" type="TextureRect" parent="."]
+[node name="SplitScreen" type="Node" parent="."]
+script = ExtResource( 2 )
+
+[node name="View" type="TextureRect" parent="SplitScreen"]
 material = SubResource( 1 )
 anchor_right = 1.0
 anchor_bottom = 1.0
 texture = ExtResource( 4 )
 expand = true
 
-[node name="Cameras" type="Spatial" parent="."]
-script = ExtResource( 2 )
-
-[node name="Viewport1" type="Viewport" parent="Cameras"]
+[node name="Main" type="Viewport" parent="SplitScreen"]
 size = Vector2( 100, 100 )
 msaa = 2
 usage = 3
 render_target_v_flip = true
 render_target_update_mode = 3
 
-[node name="Camera1" type="Camera" parent="Cameras/Viewport1"]
+[node name="Level" parent="SplitScreen/Main" instance=ExtResource( 1 )]
+
+[node name="Camera" type="Camera" parent="SplitScreen/Main"]
 transform = Transform( 1, 0, 0, 0, -4.37114e-08, 1, 0, -1, -4.37114e-08, 0, 20, 0 )
 current = true
 
-[node name="Viewport2" type="Viewport" parent="Cameras"]
+[node name="Secondary" type="Viewport" parent="SplitScreen"]
 size = Vector2( 100, 100 )
 msaa = 2
 usage = 3
 render_target_v_flip = true
 render_target_update_mode = 3
 
-[node name="Camera2" type="Camera" parent="Cameras/Viewport2"]
+[node name="Camera" type="Camera" parent="SplitScreen/Secondary"]
 transform = Transform( 1, 0, 0, 0, -4.37114e-08, 1, 0, -1, -4.37114e-08, 0, 20, 0 )
 current = true
-
-[node name="Level" parent="." instance=ExtResource( 1 )]

viewport/dynamic_split_screen/3d/camera_controller.gd → viewport/dynamic_split_screen/camera_controller.gd

@@ -5,7 +5,7 @@ extends Node
 # SplitScreen shader to achieve the dynamic split screen effet
 #
 # Cameras are placed on the segment joining the two players, either in the middle
-# if players are close enough or at a fixed distance if they are not.
+# if players are close enough or at a fixed distance from them if they are not.
 # In the first case, both cameras being at the same location, only the view of
 # the first one is used for the entire screen thus allowing the players to play
 # on an unsplit screen.
@@ -21,28 +21,36 @@ extends Node
 #       split_line_thickness. If false, the thickness will be constant and equal
 #       to split_line_thickness.
 
+
+enum Mode {
+	Mode2D,
+	Mode3D
+}
+
 export(float) var max_separation = 20.0
 export(float) var split_line_thickness = 3.0
 export(Color, RGBA) var split_line_color = Color.black
 export(bool) var adaptive_split_line_thickness = true
 
-onready var player1 = $"/root/Main/Level/Player1"
-onready var player2 = $"/root/Main/Level/Player2"
-onready var view = $"/root/Main/View"
-onready var viewport1 = $Viewport1
-onready var viewport2 = $Viewport2
-onready var camera1 = viewport1.get_node(@"Camera1")
-onready var camera2 = viewport2.get_node(@"Camera2")
-
+onready var main_viewport = $Main
+onready var secondary_viewport = $Secondary
+onready var level = main_viewport.get_node(@"Level")
+onready var player1 = level.get_node(@"Player1")
+onready var player2 = level.get_node(@"Player2")
+onready var view = $View
+onready var camera1 = main_viewport.get_node(@"Camera")
+onready var camera2 = secondary_viewport.get_node(@"Camera")
+onready var mode = Mode.Mode2D if camera1 is Camera2D else Mode.Mode3D
 
 func _ready():
+	secondary_viewport.world_2d = main_viewport.world_2d
 	_on_size_changed()
 	_update_splitscreen()
 
 	get_viewport().connect("size_changed", self, "_on_size_changed")
 
-	view.material.set_shader_param("viewport1", viewport1.get_texture())
-	view.material.set_shader_param("viewport2", viewport2.get_texture())
+	view.material.set_shader_param("viewport1", main_viewport.get_texture())
+	view.material.set_shader_param("viewport2", secondary_viewport.get_texture())
 
 
 func _process(_delta):
@@ -57,17 +65,30 @@ func _move_cameras():
 
 	position_difference = position_difference.normalized() * distance
 
-	camera1.translation.x = player1.translation.x + position_difference.x / 2.0
-	camera1.translation.z = player1.translation.z + position_difference.z / 2.0
+	match mode:
+		Mode.Mode2D:
+			camera1.position = player1.position + position_difference / 2.0
+			camera2.position = player2.position - position_difference / 2.0
+		Mode.Mode3D:
+			camera1.translation.x = player1.translation.x + position_difference.x / 2.0
+			camera1.translation.z = player1.translation.z + position_difference.z / 2.0
 
-	camera2.translation.x = player2.translation.x - position_difference.x / 2.0
-	camera2.translation.z = player2.translation.z - position_difference.z / 2.0
+			camera2.translation.x = player2.translation.x - position_difference.x / 2.0
+			camera2.translation.z = player2.translation.z - position_difference.z / 2.0
 
 
 func _update_splitscreen():
 	var screen_size = get_viewport().get_visible_rect().size
-	var player1_position = camera1.unproject_position(player1.translation) / screen_size
-	var player2_position = camera2.unproject_position(player2.translation) / screen_size
+	var player1_position
+	var player2_position
+
+	match mode:
+		Mode.Mode2D:
+			player1_position = (player1.position - camera1.position) / (camera1.zoom * screen_size) + Vector2(0.5, 0.5)
+			player2_position = (player2.position - camera2.position) / (camera2.zoom * screen_size) + Vector2(0.5, 0.5)
+		Mode.Mode3D:
+			player1_position = camera1.unproject_position(player1.translation) / screen_size
+			player2_position = camera2.unproject_position(player2.translation) / screen_size
 
 	var thickness
 	if adaptive_split_line_thickness:
@@ -87,7 +108,7 @@ func _update_splitscreen():
 
 
 # Split screen is active if players are too far apart from each other.
-# Only the horizontal components (x, z) are used for distance computation
+# Only the horizontal components (x/z in 3D, x/y in 2D) are used for distance computation
 func _get_split_state():
 	var position_difference = _compute_position_difference_in_world()
 	var separation_distance = _compute_horizontal_length(position_difference)
@@ -97,15 +118,15 @@ func _get_split_state():
 func _on_size_changed():
 	var screen_size = get_viewport().get_visible_rect().size
 
-	$Viewport1.size = screen_size
-	$Viewport2.size = screen_size
+	main_viewport.size = screen_size
+	secondary_viewport.size = screen_size
 
 	view.material.set_shader_param("viewport_size", screen_size)
 
 
 func _compute_position_difference_in_world():
-	return player2.translation - player1.translation
+	return player2.position - player1.position if mode == Mode.Mode2D else player2.translation - player1.translation
 
 
 func _compute_horizontal_length(vec):
-	return Vector2(vec.x, vec.z).length()
+	return Vector2(vec.x, vec.y).length() if mode == Mode.Mode2D else Vector2(vec.x, vec.z).length()