virtualx-engine/modules/openxr/extensions/openxr_hand_tracking_extension.h

/**************************************************************************/
/*  openxr_hand_tracking_extension.h                                      */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
/*                        https://godotengine.org                         */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
/*                                                                        */
/* Permission is hereby granted, free of charge, to any person obtaining  */
/* a copy of this software and associated documentation files (the        */
/* "Software"), to deal in the Software without restriction, including    */
/* without limitation the rights to use, copy, modify, merge, publish,    */
/* distribute, sublicense, and/or sell copies of the Software, and to     */
/* permit persons to whom the Software is furnished to do so, subject to  */
/* the following conditions:                                              */
/*                                                                        */
/* The above copyright notice and this permission notice shall be         */
/* included in all copies or substantial portions of the Software.        */
/*                                                                        */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
/**************************************************************************/

#ifndef OPENXR_HAND_TRACKING_EXTENSION_H
#define OPENXR_HAND_TRACKING_EXTENSION_H

#include "openxr_extension_wrapper.h"

#include "../util.h"

#define MAX_OPENXR_TRACKED_HANDS 2

class OpenXRHandTrackingExtension : public OpenXRExtensionWrapper {
public:
	struct HandTracker {
		bool is_initialized = false;
		XrHandJointsMotionRangeEXT motion_range = XR_HAND_JOINTS_MOTION_RANGE_UNOBSTRUCTED_EXT;

		XrHandTrackerEXT hand_tracker = XR_NULL_HANDLE;
		XrHandJointLocationEXT joint_locations[XR_HAND_JOINT_COUNT_EXT];
		XrHandJointVelocityEXT joint_velocities[XR_HAND_JOINT_COUNT_EXT];

		XrHandTrackingAimStateFB aimState;
		XrHandJointVelocitiesEXT velocities;
		XrHandJointLocationsEXT locations;
	};

	static OpenXRHandTrackingExtension *get_singleton();

	OpenXRHandTrackingExtension();
	virtual ~OpenXRHandTrackingExtension() override;

	virtual HashMap<String, bool *> get_requested_extensions() override;

	virtual void on_instance_created(const XrInstance p_instance) override;
	virtual void on_instance_destroyed() override;
	virtual void on_session_destroyed() override;

	virtual void *set_system_properties_and_get_next_pointer(void *p_next_pointer) override;
	virtual void on_state_ready() override;
	virtual void on_process() override;
	virtual void on_state_stopping() override;

	bool get_active();
	const HandTracker *get_hand_tracker(uint32_t p_hand) const;

	XrHandJointsMotionRangeEXT get_motion_range(uint32_t p_hand) const;
	void set_motion_range(uint32_t p_hand, XrHandJointsMotionRangeEXT p_motion_range);

private:
	static OpenXRHandTrackingExtension *singleton;

	// state
	XrSystemHandTrackingPropertiesEXT handTrackingSystemProperties;
	HandTracker hand_trackers[MAX_OPENXR_TRACKED_HANDS]; // Fixed for left and right hand

	// related extensions
	bool hand_tracking_ext = false;
	bool hand_motion_range_ext = false;
	bool hand_tracking_aim_state_ext = false;

	// functions
	void cleanup_hand_tracking();

	// OpenXR API call wrappers
	EXT_PROTO_XRRESULT_FUNC3(xrCreateHandTrackerEXT, (XrSession), p_session, (const XrHandTrackerCreateInfoEXT *), p_createInfo, (XrHandTrackerEXT *), p_handTracker)
	EXT_PROTO_XRRESULT_FUNC1(xrDestroyHandTrackerEXT, (XrHandTrackerEXT), p_handTracker)
	EXT_PROTO_XRRESULT_FUNC3(xrLocateHandJointsEXT, (XrHandTrackerEXT), p_handTracker, (const XrHandJointsLocateInfoEXT *), p_locateInfo, (XrHandJointLocationsEXT *), p_locations)
};

#endif // OPENXR_HAND_TRACKING_EXTENSION_H