Refactor overlay support to use SubViewportContainer

demo/overlay_main.gd

@@ -0,0 +1,14 @@
+extends Node
+
+var _xr_interface_openvr : XRInterfaceOpenVR
+
+
+func _enter_tree():
+	_xr_interface_openvr = OpenVRInterface.get_interface()
+
+	_xr_interface_openvr.set_application_type(2)
+	_xr_interface_openvr.set_tracking_universe(1)
+
+	if not _xr_interface_openvr.initialize():
+		print("Failed to connect to OpenVR")
+

demo/overlay_main.tscn

@@ -0,0 +1,38 @@
+[gd_scene load_steps=2 format=3 uid="uid://c2n2wcnoskmmr"]
+
+[ext_resource type="Script" path="res://overlay_main.gd" id="1_jfubd"]
+
+[node name="OverlayMain" type="HBoxContainer"]
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+script = ExtResource("1_jfubd")
+
+[node name="Label" type="Label" parent="."]
+layout_mode = 2
+text = "This is a demo of creating anOpenVR Overlay from a SubViewport!
+
+Use Run Current Scene (F6) to try this."
+horizontal_alignment = 1
+vertical_alignment = 1
+
+[node name="OpenVROverlayContainer" type="OpenVROverlayContainer" parent="."]
+absolute_position = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1.4, -1.4)
+layout_mode = 2
+size_flags_horizontal = 3
+stretch = true
+
+[node name="SubViewport" type="SubViewport" parent="OpenVROverlayContainer"]
+handle_input_locally = false
+size = Vector2i(639, 648)
+render_target_update_mode = 4
+
+[node name="Label" type="Label" parent="OpenVROverlayContainer/SubViewport"]
+offset_right = 634.0
+offset_bottom = 648.0
+size_flags_vertical = 3
+text = "I appear in an overlay too!"
+horizontal_alignment = 1
+vertical_alignment = 1

src/open_vr/openvr_data.cpp

@@ -515,14 +515,14 @@ int openvr_data::get_overlay_count() {
 	return (int)overlays.size();
 }
 
-openvr_data::overlay openvr_data::get_overlay(int p_overlay_id) {
-	return overlays[p_overlay_id];
+openvr_data::overlay *openvr_data::get_overlay(int p_overlay_id) {
+	return &overlays[p_overlay_id];
 }
 
-int openvr_data::add_overlay(vr::VROverlayHandle_t p_new_value, godot::RID p_viewport_rid) {
+int openvr_data::add_overlay(vr::VROverlayHandle_t p_new_value, ObjectID p_container_instance_id) {
 	overlay new_entry;
 	new_entry.handle = p_new_value;
-	new_entry.viewport_rid = p_viewport_rid;
+	new_entry.container_instance_id = p_container_instance_id;
 
 	overlays.push_back(new_entry);
 	return (int)overlays.size() - 1;
@@ -645,6 +645,15 @@ void openvr_data::pre_render_update() {
 
 ////////////////////////////////////////////////////////////////
 // Interact with tracking info
+vr::TrackedDeviceIndex_t openvr_data::get_tracked_device_index(Ref<XRPositionalTracker> p_tracker) {
+	for (uint32_t i = 0; i < vr::k_unMaxTrackedDeviceCount; i++) {
+		if (tracked_devices[i].tracker == p_tracker) {
+			return i;
+		}
+	}
+
+	return vr::k_unTrackedDeviceIndexInvalid;
+}
 
 ////////////////////////////////////////////////////////////////
 // Register an action set

src/open_vr/openvr_data.h

@@ -42,19 +42,18 @@ class openvr_data {
 		RAW
 	};
 
+	struct overlay {
+		vr::VROverlayHandle_t handle;
+		ObjectID container_instance_id;
+	};
+
 private:
 	static openvr_data *singleton;
 
 	int use_count;
 
 	vr::IVRRenderModels *render_models;
 
-	// structure to record which overlays go with which viewport
-	struct overlay {
-		vr::VROverlayHandle_t handle;
-		godot::RID viewport_rid;
-	};
-
 	std::vector<overlay> overlays;
 
 	OpenVRApplicationType application_type;
@@ -186,12 +185,13 @@ class openvr_data {
 
 	// interact with tracking info
 	const godot::Transform3D get_hmd_transform() const;
+	vr::TrackedDeviceIndex_t get_tracked_device_index(Ref<XRPositionalTracker> p_tracker);
 
 	////////////////////////////////////////////////////////////////
 	// overlay
 	int get_overlay_count();
-	overlay get_overlay(int p_overlay_id);
-	int add_overlay(vr::VROverlayHandle_t p_new_value, godot::RID p_viewport_rid);
+	overlay *get_overlay(int p_overlay_id);
+	int add_overlay(vr::VROverlayHandle_t p_new_value, ObjectID p_container_instance_id);
 	void remove_overlay(int p_overlay_id);
 
 	////////////////////////////////////////////////////////////////

src/open_vr/openvr_overlay_container.h

@@ -0,0 +1,63 @@
+#ifndef OPENVR_OVERLAY_CONTAINER_H
+#define OPENVR_OVERLAY_CONTAINER_H
+
+#include "openvr_data.h"
+#include <godot_cpp/classes/project_settings.hpp>
+#include <godot_cpp/classes/sub_viewport_container.hpp>
+#include <godot_cpp/templates/hash_set.hpp>
+#include <godot_cpp/variant/transform3d.hpp>
+
+namespace godot {
+class OpenVROverlayContainer : public SubViewportContainer {
+	GDCLASS(OpenVROverlayContainer, SubViewportContainer)
+
+private:
+	openvr_data *ovr;
+	vr::VROverlayHandle_t overlay;
+	int overlay_id;
+
+	float overlay_width_in_meters;
+	bool overlay_visible;
+	HashSet<vr::VROverlayFlags> initial_flags;
+
+	String tracked_device_name;
+	Transform3D absolute_position; // Used when tracked_device == ""
+	Transform3D tracked_device_relative_position; // Used when tracked_device != ""
+
+	void on_frame_post_draw();
+	void draw_overlay(const Ref<Texture2D> &p_texture);
+
+	bool update_overlay_transform();
+
+protected:
+	static void _bind_methods();
+
+public:
+	OpenVROverlayContainer();
+	~OpenVROverlayContainer();
+
+	void _notification(int p_what);
+
+	bool get_flag(vr::VROverlayFlags p_flag);
+	void set_flag(vr::VROverlayFlags p_flag, bool p_state);
+
+	float get_overlay_width_in_meters();
+	void set_overlay_width_in_meters(float p_new_size);
+
+	bool is_overlay_visible();
+	void set_overlay_visible(bool p_visible);
+
+	String get_tracked_device_name();
+	void set_tracked_device_name(String p_tracked_device_name);
+
+	Transform3D get_absolute_position();
+	void set_absolute_position(Transform3D p_position);
+
+	Transform3D get_tracked_device_relative_position();
+	void set_tracked_device_relative_position(Transform3D p_position);
+};
+} // namespace godot
+
+VARIANT_ENUM_CAST(vr::VROverlayFlags);
+
+#endif /* !OPENVR_OVERLAY_CONTAINER_H */

src/register_types.cpp

@@ -14,9 +14,9 @@
 #include <godot_cpp/godot.hpp>
 #include <godot_cpp/variant/utility_functions.hpp>
 
-#include "OpenVROverlay.h"
 #include "OpenVRRenderModel.h"
 #include "OpenVRSkeleton.h"
+#include "openvr_overlay_container.h"
 #include "xr_interface_openvr.h"
 
 using namespace godot;
@@ -31,7 +31,7 @@ void initialize_gdextension_types(ModuleInitializationLevel p_level) {
 	}
 
 	ClassDB::register_class<XRInterfaceOpenVR>();
-	ClassDB::register_class<OpenVROverlay>();
+	ClassDB::register_class<OpenVROverlayContainer>();
 	ClassDB::register_class<OpenVRRenderModel>();
 	ClassDB::register_class<OpenVRSkeleton>();
 }

src/xr_interface_openvr.cpp

@@ -359,6 +359,11 @@ void XRInterfaceOpenVR::_end_frame() {
 		return;
 	}
 
+	if (!texture_rid.is_valid()) {
+		// No texture means we're not actually rendering a full scene. Probably in overlay mode, but regardless we bail out of this.
+		return;
+	}
+
 	RenderingServer *rendering_server = RenderingServer::get_singleton();
 	ERR_FAIL_NULL(rendering_server);
 	RenderingDevice *rendering_device = rendering_server->get_rendering_device();