WIP: Add openxr overlay support to the demo project

Adds a WorldEnvironment to the Main node instead of relying on default_env.tres.
While a main session is not visible, env mode is sky.
If a main session is visible, env mode is a custom color with alpha = 0.

Author: ChristophHaag

Diff for: demo/Main.gd

@@ -9,6 +9,12 @@ func _ready():
 	print("Supported refresh rates: " + str($FPSController/Configuration.get_available_refresh_rates()))
 	print("Supported color spaces: " + str($FPSController/Configuration.get_available_color_spaces()))
 	print("Current color space: " + str($FPSController/Configuration.get_color_space()))
+	print("Main session visible: " + str($FPSController/Configuration.get_main_session_visible()))
+
+	# Makes the background just black, but not transparent
+	#get_tree().get_root().set_transparent_background(true)
+
+var main_session_visible = false;
 
 func _process(delta):
 	# Test for escape to close application, space to reset our reference frame
@@ -33,3 +39,22 @@ func _process(delta):
 	# this is a little dirty but we're going to just tie the trigger input of our controllers to their haptic output for testing
 	$FPSController/LeftHandController.rumble = $FPSController/LeftHandController.get_joystick_axis(JOY_VR_ANALOG_TRIGGER)
 	$FPSController/RightHandController.rumble = $FPSController/RightHandController.get_joystick_axis(JOY_VR_ANALOG_TRIGGER)
+
+	var main_session_visible_now = $FPSController/Configuration.get_main_session_visible();
+	var main_session_visible_changed = main_session_visible != main_session_visible_now
+	main_session_visible = main_session_visible_now
+
+	if  (main_session_visible_changed):
+		var env = $WorldEnvironment.get_environment()
+
+		if (main_session_visible):
+			# A main session is rendering, so our background shouldn't occlude it
+			env.background_color.a = 0.0
+
+			env.background_color.r = 1.0 # should not be visible with alpha 0
+			env.background_color.g = 0.0
+			env.background_color.b = 0.0
+			env.background_mode = Environment.BG_COLOR
+		else:
+			# No main session, we can show our background
+			env.background_mode = Environment.BG_SKY

Diff for: demo/Main.tscn

@@ -1,10 +1,11 @@
-[gd_scene load_steps=19 format=2]
+[gd_scene load_steps=20 format=2]
 
 [ext_resource path="res://Main.gd" type="Script" id=1]
 [ext_resource path="res://Ground.tscn" type="PackedScene" id=2]
 [ext_resource path="res://Table.tscn" type="PackedScene" id=3]
 [ext_resource path="res://addons/godot-openxr/scenes/first_person_controller_vr.tscn" type="PackedScene" id=4]
 [ext_resource path="res://addons/godot-openxr/assets/valve_hand_models/textures/vr_glove_color.jpg" type="Texture" id=5]
+[ext_resource path="res://default_env.tres" type="Environment" id=6]
 [ext_resource path="res://addons/godot-openxr/scenes/XRPose.tscn" type="PackedScene" id=7]
 [ext_resource path="res://addons/godot-xr-tools/objects/Viewport_2D_in_3D.tscn" type="PackedScene" id=8]
 [ext_resource path="res://ControllerInfo.tscn" type="PackedScene" id=9]
@@ -157,6 +158,9 @@ viewport_size = Vector2( 600, 400 )
 scene = ExtResource( 12 )
 collision_layer = 1024
 
+[node name="WorldEnvironment" type="WorldEnvironment" parent="."]
+environment = ExtResource( 6 )
+
 [editable path="FPSController"]
 [editable path="FPSController/LeftHand"]
 [editable path="FPSController/LeftHand/HandModel"]

Diff for: demo/project.godot

@@ -47,6 +47,10 @@ Fire={
 3d_physics/layer_3="Objects"
 3d_physics/layer_11="UI"
 
+[network]
+
+limits/debugger_stdout/max_chars_per_second=4096
+
 [rendering]
 
 quality/driver/driver_name="GLES2"