Added initial WebXR entry UI and export target.

Added thread support to handle resource queue loading.

Added new StartXR scene to manage starting the OpenXR or WebXR instance. Fixed loading_screen so it doesn't produce NANs when the headset is off for a while.

Fixed minor gdlint warnings.

Move ARVROrigin/camera/controllers into base staging scene. Move StartXR into base staging scene. Modified base staging scene to emit xr_started/xr_ended signals.

Synchronized with Godot 4 equivalent functionality and events.

Formatting fixes

addons/godot-xr-tools/staging/loading_screen.gd

@@ -68,26 +68,23 @@ func _process(delta):
 	if !_camera:
 		return
 
-	var camera_dir = _camera.global_transform.basis.z
+	# Get the camera direction (horizontal only)
+	var camera_dir := _camera.global_transform.basis.z
 	camera_dir.y = 0.0
 	camera_dir = camera_dir.normalized()
 
-	var loading_screen_dir = global_transform.basis.z
+	# Get the loading screen direction
+	var loading_screen_dir := global_transform.basis.z
 
-	# Calculate the rotation-axis to rotate the screen in front of the camera
-	var cross = loading_screen_dir.cross(camera_dir)
-	if cross.is_equal_approx(Vector3.ZERO):
+	# Get the angle
+	var angle := loading_screen_dir.signed_angle_to(camera_dir, Vector3.UP)
+	if angle == 0:
 		return
 
-	# Calculate the angle to rotate the screen in front of the camera
-	cross = cross.normalized()
-	var dot = loading_screen_dir.dot(camera_dir)
-	var angle = acos(dot)
-
 	# Do rotation based on the curve
 	global_transform.basis = global_transform.basis.rotated(
-			cross,
-			follow_speed.interpolate_baked(angle / PI) * delta
+			Vector3.UP * sign(angle),
+			follow_speed.interpolate_baked(abs(angle) / PI) * delta
 	).orthonormalized()
 
 

addons/godot-xr-tools/staging/staging.gd

@@ -40,6 +40,12 @@ signal scene_loaded(scene)
 ## New scene is now visible
 signal scene_visible(scene)
 
+## XR interaction started
+signal xr_started
+
+## XR interaction ended
+signal xr_ended
+
 
 ## Main scene file
 export (String, FILE, '*.tscn') var main_scene : String
@@ -259,3 +265,11 @@ func _on_exit_to_main_menu():
 
 func _on_load_scene(p_scene_path : String):
 	load_scene(p_scene_path)
+
+
+func _on_StartXR_xr_started():
+	emit_signal("xr_started")
+
+
+func _on_StartXR_xr_ended():
+	emit_signal("xr_ended")

addons/godot-xr-tools/staging/staging.tscn

@@ -1,8 +1,10 @@
-[gd_scene load_steps=8 format=2]
+[gd_scene load_steps=10 format=2]
 
+[ext_resource path="res://addons/godot-xr-tools/misc/vr_common_shader_cache.tscn" type="PackedScene" id=1]
 [ext_resource path="res://addons/godot-xr-tools/staging/staging.gd" type="Script" id=2]
 [ext_resource path="res://addons/godot-xr-tools/staging/loading_screen.tscn" type="PackedScene" id=3]
 [ext_resource path="res://addons/godot-xr-tools/staging/fade.gdshader" type="Shader" id=4]
+[ext_resource path="res://addons/godot-xr-tools/xr/start_xr.tscn" type="PackedScene" id=5]
 
 [sub_resource type="QuadMesh" id=4]
 custom_aabb = AABB( -5000, -5000, -5000, 10000, 10000, 10000 )
@@ -29,9 +31,27 @@ material/0 = SubResource( 3 )
 environment = SubResource( 2 )
 
 [node name="LoadingScreen" parent="." instance=ExtResource( 3 )]
-splash_screen = null
 progress = 0.0
 
 [node name="Scene" type="Spatial" parent="."]
 
 [node name="Tween" type="Tween" parent="."]
+
+[node name="ARVROrigin" type="ARVROrigin" parent="."]
+
+[node name="ARVRCamera" type="ARVRCamera" parent="ARVROrigin"]
+transform = Transform( 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1.8, 0 )
+
+[node name="VRCommonShaderCache" parent="ARVROrigin/ARVRCamera" instance=ExtResource( 1 )]
+
+[node name="LeftHand" type="ARVRController" parent="ARVROrigin"]
+transform = Transform( 1, 0, 0, 0, 1, 0, 0, 0, 1, -0.5, 1, -0.5 )
+
+[node name="RightHand" type="ARVRController" parent="ARVROrigin"]
+transform = Transform( 1, 0, 0, 0, 1, 0, 0, 0, 1, 0.5, 1, -0.5 )
+controller_id = 2
+
+[node name="StartXR" parent="." instance=ExtResource( 5 )]
+
+[connection signal="xr_ended" from="StartXR" to="." method="_on_StartXR_xr_ended"]
+[connection signal="xr_started" from="StartXR" to="." method="_on_StartXR_xr_started"]

addons/godot-xr-tools/xr/start_xr.gd

@@ -0,0 +1,273 @@
+tool
+class_name XRToolsStartXR
+extends Node
+
+
+## XRTools Start XR Class
+##
+## This class supports both the OpenXR and WebXR interfaces, and handles
+## the initialization of the interface as well as reporting when the user
+## starts and ends the VR session.
+##
+## For OpenXR this class also supports passthrough on compatible devices such
+## as the Meta Quest 1 and 2.
+
+
+## This signal is emitted when XR becomes active. For OpenXR this corresponds
+## with the 'openxr_focused_state' signal which occurs when the application
+## starts receiving XR input, and for WebXR this corresponds with the
+## 'session_started' signal.
+signal xr_started
+
+## This signal is emitted when XR ends. For OpenXR this corresponds with the
+## 'openxr_visible_state' state which occurs when the application has lost
+## XR input focus, and for WebXR this corresponds with the 'session_ended'
+## signal.
+signal xr_ended
+
+
+## If true, the XR interface is automatically initialized
+export var auto_initialize : bool = true
+
+## If true, the XR passthrough is enabled (OpenXR only)
+export var enable_passthrough : bool = false setget _set_enable_passthrough
+
+## Physics rate multiplier compared to HMD frame rate
+export var physics_rate_multiplier : float = 1
+
+
+## Current XR interface
+var xr_interface : ARVRInterface
+
+## XR active flag
+var xr_active : bool = false
+
+# OpenXR configuration (of type OpenXRConfig.gdns)
+var _openxr_configuration
+
+# OpenXR enabled extensions
+var _openxr_enabled_extensions : Array
+
+
+# Handle auto-initialization when ready
+func _ready() -> void:
+	if !Engine.editor_hint and auto_initialize:
+		initialize()
+
+
+## Initialize the XR interface
+func initialize() -> bool:
+	# Check for OpenXR interface
+	xr_interface = ARVRServer.find_interface('OpenXR')
+	if xr_interface:
+		_setup_for_openxr()
+		return true
+
+	# Check for WebXR interface
+	xr_interface = ARVRServer.find_interface('WebXR')
+	if xr_interface:
+		_setup_for_webxr()
+		return true
+
+	# No XR interface
+	xr_interface = null
+	print("No XR interface detected")
+	return false
+
+
+# Check for configuration issues
+func _get_configuration_warning():
+	if physics_rate_multiplier < 1.0:
+		return "Physics rate multiplier should be at least 1x the HMD rate"
+
+	return ""
+
+
+# Perform OpenXR setup
+func _setup_for_openxr() -> void:
+	print("OpenXR: Configuring interface")
+
+	# Load the OpenXR configuration resource
+	var openxr_config_res := load("res://addons/godot-openxr/config/OpenXRConfig.gdns")
+	if not openxr_config_res:
+		push_error("OpenXR: Unable to load OpenXRConfig.gdns")
+		return
+
+	# Create the OpenXR configuration class
+	_openxr_configuration = openxr_config_res.new()
+
+	# Initialize the OpenXR interface
+	if not xr_interface.initialize():
+		push_error("OpenXR: Failed to initialize")
+		return
+
+	# Connect the OpenXR events
+	ARVRServer.connect("openxr_session_begun", self, "_on_openxr_session_begun")
+	ARVRServer.connect("openxr_visible_state", self, "_on_openxr_visible_state")
+	ARVRServer.connect("openxr_focused_state", self, "_on_openxr_focused_state")
+
+	# Read the OpenXR enabled extensions
+	_openxr_enabled_extensions = _openxr_configuration.get_enabled_extensions()
+
+	# Check for passthrough
+	if enable_passthrough and _openxr_is_passthrough_supported():
+		enable_passthrough = _openxr_start_passthrough()
+
+	# Switch the viewport to XR
+	get_viewport().arvr = true
+
+
+# Handle OpenXR session ready
+func _on_openxr_session_begun() -> void:
+	print("OpenXR: Session begun")
+
+	# Our interface will tell us whether we should keep our render buffer in linear color space
+	get_viewport().keep_3d_linear = _openxr_configuration.keep_3d_linear()
+
+	# increase our physics engine update speed
+	var refresh_rate : float = _openxr_configuration.get_refresh_rate()
+	if refresh_rate > 0:
+		# Report provided frame rare
+		print("OpenXR: HMD refresh rate is set to ", str(refresh_rate))
+	else:
+		# None provided, assume a standard rate
+		print("OpenXR: No refresh rate given by XR runtime")
+		refresh_rate = 144
+
+	# Pick a physics rate
+	var physics_rate := int(refresh_rate * physics_rate_multiplier + 0.5)
+	print("Setting physics rate to ", physics_rate)
+	Engine.iterations_per_second = physics_rate
+
+
+# Handle OpenXR visible state
+func _on_openxr_visible_state() -> void:
+	# Report the XR ending
+	if xr_active:
+		print("OpenXR: XR ended (visible_state)")
+		xr_active = false
+		emit_signal("xr_ended")
+
+
+# Handle OpenXR focused state
+func _on_openxr_focused_state() -> void:
+	# Report the XR starting
+	if not xr_active:
+		print("OpenXR: XR started (focused_state)")
+		xr_active = true
+		emit_signal("xr_started")
+
+
+# Handle changes to the enable_passthrough property
+func _set_enable_passthrough(p_new_value : bool) -> void:
+	# Save the new value
+	enable_passthrough = p_new_value
+
+	# Only actually start our passthrough if our interface has been instanced
+	# if not this will be delayed until initialise is successfully called.
+	if xr_interface and _openxr_configuration:
+		if enable_passthrough:
+			# unset enable_passthrough if we can't start it.
+			enable_passthrough = _openxr_start_passthrough()
+		else:
+			_openxr_stop_passthrough()
+
+
+# Test if passthrough is supported
+func _openxr_is_passthrough_supported() -> bool:
+	return _openxr_enabled_extensions.find("XR_FB_passthrough") >= 0
+
+
+# Start OpenXR passthrough
+func _openxr_start_passthrough() -> bool:
+	# Set viewport transparent background
+	get_viewport().transparent_bg = true
+
+	# Enable passthrough
+	return _openxr_configuration.start_passthrough()
+
+
+# Stop OpenXR passthrough
+func _openxr_stop_passthrough() -> void:
+	# Clear viewport transparent background
+	get_viewport().transparent_bg = false
+
+	# Disable passthrough
+	_openxr_configuration.stop_passthrough()
+
+
+# Perform WebXR setup
+func _setup_for_webxr() -> void:
+	print("WebXR: Configuring interface")
+
+	# Connect the WebXR events
+	xr_interface.connect("session_supported", self, "_on_webxr_session_supported")
+	xr_interface.connect("session_started", self, "_on_webxr_session_started")
+	xr_interface.connect("session_ended", self, "_on_webxr_session_ended")
+	xr_interface.connect("session_failed", self, "_on_webxr_session_failed")
+
+	# WebXR currently has no means of querying the refresh rate, so use
+	# something sufficiently high
+	Engine.iterations_per_second = 144
+
+	# This returns immediately - our _webxr_session_supported() method
+	# (which we connected to the "session_supported" signal above) will
+	# be called sometime later to let us know if it's supported or not.
+	xr_interface.is_session_supported("immersive-vr")
+
+
+# Handle WebXR session supported check
+func _on_webxr_session_supported(session_mode: String, supported: bool) -> void:
+	if session_mode == "immersive-vr":
+		if supported:
+			# WebXR supported - show canvas on web browser to enter WebVR
+			$EnterWebXR.visible = true
+		else:
+			OS.alert("Your web browser doesn't support VR. Sorry!")
+
+
+# Called when the WebXR session has started successfully
+func _on_webxr_session_started() -> void:
+	print("WebXR: Session started")
+
+	# Hide the canvas and switch the viewport to XR
+	$EnterWebXR.visible = false
+	get_viewport().arvr = true
+
+	# Report the XR starting
+	xr_active = true
+	emit_signal("xr_started")
+
+
+# Called when the user ends the immersive VR session
+func _on_webxr_session_ended() -> void:
+	print("WebXR: Session ended")
+
+	# Show the canvas and switch the viewport to non-XR
+	$EnterWebXR.visible = true
+	get_viewport().arvr = false
+
+	# Report the XR ending
+	xr_active = false
+	emit_signal("xr_ended")
+
+
+# Called when the immersive VR session fails to start
+func _on_webxr_session_failed(message: String) -> void:
+	OS.alert("Unable to enter VR: " + message)
+	$EnterWebXR.visible = true
+
+
+# Handle the Enter VR button on the WebXR browser
+func _on_enter_webxr_button_pressed() -> void:
+	# Configure the WebXR interface
+	xr_interface.session_mode = 'immersive-vr'
+	xr_interface.requested_reference_space_types = 'bounded-floor, local-floor, local'
+	xr_interface.required_features = 'local-floor'
+	xr_interface.optional_features = 'bounded-floor'
+	xr_interface.xr_standard_mapping = true
+
+	# Initialize the interface. This should trigger either _on_webxr_session_started
+	# or _on_webxr_session_failed
+	if not xr_interface.initialize():
+		OS.alert("Failed to initialize WebXR")

addons/godot-xr-tools/xr/start_xr.tscn

@@ -0,0 +1,22 @@
+[gd_scene load_steps=2 format=2]
+
+[ext_resource path="res://addons/godot-xr-tools/xr/start_xr.gd" type="Script" id=1]
+
+[node name="StartXR" type="Node"]
+script = ExtResource( 1 )
+
+[node name="EnterWebXR" type="CanvasLayer" parent="."]
+visible = false
+
+[node name="EnterVRButton" type="Button" parent="EnterWebXR"]
+anchor_left = 0.5
+anchor_top = 0.5
+anchor_right = 0.5
+anchor_bottom = 0.5
+margin_left = -132.0
+margin_top = -52.5
+margin_right = 132.0
+margin_bottom = 52.5
+text = "Enter VR"
+
+[connection signal="pressed" from="EnterWebXR/EnterVRButton" to="." method="_on_enter_webxr_button_pressed"]