/************************************************************************************

Copyright   :   Copyright 2014 Oculus VR, LLC. All Rights reserved.

Licensed under the Oculus VR Rift SDK License Version 3.4.1 (the "License");
you may not use the Oculus VR Rift SDK except in compliance with the License,
which is provided at the time of installation or download, or which
otherwise accompanies this software in either electronic or hard copy form.

You may obtain a copy of the License at

https://developer.oculus.com/licenses/sdk-3.4.1

Unless required by applicable law or agreed to in writing, the Oculus VR SDK
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

************************************************************************************/

#if !UNITY_5_6_OR_NEWER
#error Oculus Utilities require Unity 5.6 or higher.
#endif

using System;
using System.Collections.Generic;
using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;
#endif

/// <summary>
/// Configuration data for Oculus virtual reality.
/// </summary>
public class OVRManager : MonoBehaviour
{
	public enum TrackingOrigin
	{
		EyeLevel   = OVRPlugin.TrackingOrigin.EyeLevel,
		FloorLevel = OVRPlugin.TrackingOrigin.FloorLevel,
	}

	public enum EyeTextureFormat
	{
		Default = OVRPlugin.EyeTextureFormat.Default,
		R16G16B16A16_FP = OVRPlugin.EyeTextureFormat.R16G16B16A16_FP,
		R11G11B10_FP = OVRPlugin.EyeTextureFormat.R11G11B10_FP,
	}

	public enum TiledMultiResLevel
	{
		Off = OVRPlugin.TiledMultiResLevel.Off,
		LMSLow = OVRPlugin.TiledMultiResLevel.LMSLow,
		LMSMedium = OVRPlugin.TiledMultiResLevel.LMSMedium,
		LMSHigh = OVRPlugin.TiledMultiResLevel.LMSHigh,
	}

	/// <summary>
	/// Gets the singleton instance.
	/// </summary>
	public static OVRManager instance { get; private set; }

	/// <summary>
	/// Gets a reference to the active display.
	/// </summary>
	public static OVRDisplay display { get; private set; }

	/// <summary>
	/// Gets a reference to the active sensor.
	/// </summary>
	public static OVRTracker tracker { get; private set; }

	/// <summary>
	/// Gets a reference to the active boundary system.
	/// </summary>
	public static OVRBoundary boundary { get; private set; }

	private static OVRProfile _profile;
	/// <summary>
	/// Gets the current profile, which contains information about the user's settings and body dimensions.
	/// </summary>
	public static OVRProfile profile
	{
		get {
			if (_profile == null)
				_profile = new OVRProfile();

			return _profile;
		}
	}

	private IEnumerable<Camera> disabledCameras;
	float prevTimeScale;

	/// <summary>
	/// Occurs when an HMD attached.
	/// </summary>
	public static event Action HMDAcquired;

	/// <summary>
	/// Occurs when an HMD detached.
	/// </summary>
	public static event Action HMDLost;

	/// <summary>
	/// Occurs when an HMD is put on the user's head.
	/// </summary>
	public static event Action HMDMounted;

	/// <summary>
	/// Occurs when an HMD is taken off the user's head.
	/// </summary>
	public static event Action HMDUnmounted;

	/// <summary>
	/// Occurs when VR Focus is acquired.
	/// </summary>
	public static event Action VrFocusAcquired;

	/// <summary>
	/// Occurs when VR Focus is lost.
	/// </summary>
	public static event Action VrFocusLost;

	/// <summary>
	/// Occurs when Input Focus is acquired.
	/// </summary>
	public static event Action InputFocusAcquired;

	/// <summary>
	/// Occurs when Input Focus is lost.
	/// </summary>
	public static event Action InputFocusLost;

	/// <summary>
	/// Occurs when the active Audio Out device has changed and a restart is needed.
	/// </summary>
	public static event Action AudioOutChanged;

	/// <summary>
	/// Occurs when the active Audio In device has changed and a restart is needed.
	/// </summary>
	public static event Action AudioInChanged;

	/// <summary>
	/// Occurs when the sensor gained tracking.
	/// </summary>
	public static event Action TrackingAcquired;

	/// <summary>
	/// Occurs when the sensor lost tracking.
	/// </summary>
	public static event Action TrackingLost;

	/// <summary>
	/// Occurs when Health & Safety Warning is dismissed.
	/// </summary>
	//Disable the warning about it being unused. It's deprecated.
	#pragma warning disable 0067
	[Obsolete]
	public static event Action HSWDismissed;
	#pragma warning restore

	private static bool _isHmdPresentCached = false;
	private static bool _isHmdPresent = false;
	private static bool _wasHmdPresent = false;
	/// <summary>
	/// If true, a head-mounted display is connected and present.
	/// </summary>
	public static bool isHmdPresent
	{
		get {
			if (!_isHmdPresentCached)
			{
				_isHmdPresentCached = true;
				_isHmdPresent = OVRPlugin.hmdPresent;
			}

			return _isHmdPresent;
		}

		private set {
			_isHmdPresentCached = true;
			_isHmdPresent = value;
		}
	}

	/// <summary>
	/// Gets the audio output device identifier.
	/// </summary>
	/// <description>
	/// On Windows, this is a string containing the GUID of the IMMDevice for the Windows audio endpoint to use.
	/// </description>
	public static string audioOutId
	{
		get { return OVRPlugin.audioOutId; }
	}

	/// <summary>
	/// Gets the audio input device identifier.
	/// </summary>
	/// <description>
	/// On Windows, this is a string containing the GUID of the IMMDevice for the Windows audio endpoint to use.
	/// </description>
	public static string audioInId
	{
		get { return OVRPlugin.audioInId; }
	}

	private static bool _hasVrFocusCached = false;
	private static bool _hasVrFocus = false;
	private static bool _hadVrFocus = false;
	/// <summary>
	/// If true, the app has VR Focus.
	/// </summary>
	public static bool hasVrFocus
	{
		get {
			if (!_hasVrFocusCached)
			{
				_hasVrFocusCached = true;
				_hasVrFocus = OVRPlugin.hasVrFocus;
			}

			return _hasVrFocus;
		}

		private set {
			_hasVrFocusCached = true;
			_hasVrFocus = value;
		}
	}

	private static bool _hadInputFocus = true;
	/// <summary>
	/// If true, the app has Input Focus.
	/// </summary>
	public static bool hasInputFocus
	{
		get
		{
			return OVRPlugin.hasInputFocus;
		}
	}

	/// <summary>
	/// If true, chromatic de-aberration will be applied, improving the image at the cost of texture bandwidth.
	/// </summary>
	public bool chromatic
	{
		get {
			if (!isHmdPresent)
				return false;

			return OVRPlugin.chromatic;
		}

		set {
			if (!isHmdPresent)
				return;

			OVRPlugin.chromatic = value;
		}
	}

	/// <summary>
	/// If true, both eyes will see the same image, rendered from the center eye pose, saving performance.
	/// </summary>
	public bool monoscopic
	{
		get {
			if (!isHmdPresent)
				return true;

			return OVRPlugin.monoscopic;
		}

		set {
			if (!isHmdPresent)
				return;

			OVRPlugin.monoscopic = value;
		}
	}

	[Header("Performance/Quality")]
	/// <summary>
	/// If true, distortion rendering work is submitted a quarter-frame early to avoid pipeline stalls and increase CPU-GPU parallelism.
	/// </summary>
	[Tooltip("If true, distortion rendering work is submitted a quarter-frame early to avoid pipeline stalls and increase CPU-GPU parallelism.")]
	public bool queueAhead = true;

	/// <summary>
	/// If true, Unity will use the optimal antialiasing level for quality/performance on the current hardware.
	/// </summary>
	[Tooltip("If true, Unity will use the optimal antialiasing level for quality/performance on the current hardware.")]
	public bool useRecommendedMSAALevel = false;

	/// <summary>
	/// If true, dynamic resolution will be enabled
	/// </summary>
	[Tooltip("If true, dynamic resolution will be enabled On PC")]
	public bool enableAdaptiveResolution = false;

	/// <summary>
	/// Adaptive Resolution is based on Unity engine's renderViewportScale/eyeTextureResolutionScale feature 
	/// But renderViewportScale was broken in an array of Unity engines, this function help to filter out those broken engines
	/// </summary>
	public static bool IsAdaptiveResSupportedByEngine()
	{
#if UNITY_2017_1_OR_NEWER
		return Application.unityVersion != "2017.1.0f1";
#else
		return false;
#endif
	}

	/// <summary>
	/// Min RenderScale the app can reach under adaptive resolution mode ( enableAdaptiveResolution = true );
	/// </summary>
	[RangeAttribute(0.5f, 2.0f)]
	[Tooltip("Min RenderScale the app can reach under adaptive resolution mode")]
	public float minRenderScale = 0.7f;

	/// <summary>
	/// Max RenderScale the app can reach under adaptive resolution mode ( enableAdaptiveResolution = true );
	/// </summary>
	[RangeAttribute(0.5f, 2.0f)]
	[Tooltip("Max RenderScale the app can reach under adaptive resolution mode")]
	public float maxRenderScale = 1.0f;

#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN
	/// <summary>
	/// If true, the MixedRealityCapture properties will be displayed
	/// </summary>
	[HideInInspector]
	public bool expandMixedRealityCapturePropertySheet = false;


	/// <summary>
	/// If true, Mixed Reality mode will be enabled
	/// </summary>
	[HideInInspector, Tooltip("If true, Mixed Reality mode will be enabled. It would be always set to false when the game is launching without editor")]
	public bool enableMixedReality = false;

	public enum CompositionMethod
	{
		External,
		Direct,
		Sandwich
	}

	/// <summary>
	/// Composition method
	/// </summary>
	[HideInInspector]
	public CompositionMethod compositionMethod = CompositionMethod.External;

	/// <summary>
	/// Extra hidden layers
	/// </summary>
	[HideInInspector, Tooltip("Extra hidden layers")]
	public LayerMask extraHiddenLayers;


	/// <summary>
	/// If true, Mixed Reality mode will use direct composition from the first web camera
	/// </summary>

	public enum CameraDevice
	{
		WebCamera0,
		WebCamera1,
		ZEDCamera
	}

	/// <summary>
	/// The camera device for direct composition
	/// </summary>
	[HideInInspector, Tooltip("The camera device for direct composition")]
	public CameraDevice capturingCameraDevice = CameraDevice.WebCamera0;

	/// <summary>
	/// Flip the camera frame horizontally
	/// </summary>
	[HideInInspector, Tooltip("Flip the camera frame horizontally")]
	public bool flipCameraFrameHorizontally = false;

	/// <summary>
	/// Flip the camera frame vertically
	/// </summary>
	[HideInInspector, Tooltip("Flip the camera frame vertically")]
	public bool flipCameraFrameVertically = false;

	/// <summary>
	/// Delay the touch controller pose by a short duration (0 to 0.5 second) to match the physical camera latency
	/// </summary>
	[HideInInspector, Tooltip("Delay the touch controller pose by a short duration (0 to 0.5 second) to match the physical camera latency")]
	public float handPoseStateLatency = 0.0f;

	/// <summary>
	/// Delay the foreground / background image in the sandwich composition to match the physical camera latency. The maximum duration is sandwichCompositionBufferedFrames / {Game FPS}
	/// </summary>
	[HideInInspector, Tooltip("Delay the foreground / background image in the sandwich composition to match the physical camera latency. The maximum duration is sandwichCompositionBufferedFrames / {Game FPS}")]
	public float sandwichCompositionRenderLatency = 0.0f;

	/// <summary>
	/// The number of frames are buffered in the SandWich composition. The more buffered frames, the more memory it would consume.
	/// </summary>
	[HideInInspector, Tooltip("The number of frames are buffered in the SandWich composition. The more buffered frames, the more memory it would consume.")]
	public int sandwichCompositionBufferedFrames = 8;


	/// <summary>
	/// Chroma Key Color
	/// </summary>
	[HideInInspector, Tooltip("Chroma Key Color")]
	public Color chromaKeyColor = Color.green;

	/// <summary>
	/// Chroma Key Similarity
	/// </summary>
	[HideInInspector, Tooltip("Chroma Key Similarity")]
	public float chromaKeySimilarity = 0.60f;

	/// <summary>
	/// Chroma Key Smooth Range
	/// </summary>
	[HideInInspector, Tooltip("Chroma Key Smooth Range")]
	public float chromaKeySmoothRange = 0.03f;

	/// <summary>
	///  Chroma Key Spill Range
	/// </summary>
	[HideInInspector, Tooltip("Chroma Key Spill Range")]
	public float chromaKeySpillRange = 0.06f;

	/// <summary>
	/// Use dynamic lighting (Depth sensor required)
	/// </summary>
	[HideInInspector, Tooltip("Use dynamic lighting (Depth sensor required)")]
	public bool useDynamicLighting = false;

	public enum DepthQuality
	{
		Low,
		Medium,
		High
	}
	/// <summary>
	/// The quality level of depth image. The lighting could be more smooth and accurate with high quality depth, but it would also be more costly in performance.
	/// </summary>
	[HideInInspector, Tooltip("The quality level of depth image. The lighting could be more smooth and accurate with high quality depth, but it would also be more costly in performance.")]
	public DepthQuality depthQuality = DepthQuality.Medium;

	/// <summary>
	/// Smooth factor in dynamic lighting. Larger is smoother
	/// </summary>
	[HideInInspector, Tooltip("Smooth factor in dynamic lighting. Larger is smoother")]
	public float dynamicLightingSmoothFactor = 8.0f;

	/// <summary>
	/// The maximum depth variation across the edges. Make it smaller to smooth the lighting on the edges.
	/// </summary>
	[HideInInspector, Tooltip("The maximum depth variation across the edges. Make it smaller to smooth the lighting on the edges.")]
	public float dynamicLightingDepthVariationClampingValue = 0.001f;

	public enum VirtualGreenScreenType
	{
		Off,
		OuterBoundary,
		PlayArea
	}

	/// <summary>
	/// Set the current type of the virtual green screen
	/// </summary>
	[HideInInspector, Tooltip("Type of virutal green screen ")]
	public VirtualGreenScreenType virtualGreenScreenType = VirtualGreenScreenType.Off;

	/// <summary>
	/// Top Y of virtual screen
	/// </summary>
	[HideInInspector, Tooltip("Top Y of virtual green screen")]
	public float virtualGreenScreenTopY = 10.0f;

	/// <summary>
	/// Bottom Y of virtual screen
	/// </summary>
	[HideInInspector, Tooltip("Bottom Y of virtual green screen")]
	public float virtualGreenScreenBottomY = -10.0f;

	/// <summary>
	/// When using a depth camera (e.g. ZED), whether to use the depth in virtual green screen culling.
	/// </summary>
	[HideInInspector, Tooltip("When using a depth camera (e.g. ZED), whether to use the depth in virtual green screen culling.")]
	public bool virtualGreenScreenApplyDepthCulling = false;

	/// <summary>
	/// The tolerance value (in meter) when using the virtual green screen with a depth camera. Make it bigger if the foreground objects got culled incorrectly.
	/// </summary>
	[HideInInspector, Tooltip("The tolerance value (in meter) when using the virtual green screen with a depth camera. Make it bigger if the foreground objects got culled incorrectly.")]
	public float virtualGreenScreenDepthTolerance = 0.2f;
#endif

	/// <summary>
	/// The number of expected display frames per rendered frame.
	/// </summary>
	public int vsyncCount
	{
		get {
			if (!isHmdPresent)
				return 1;

			return OVRPlugin.vsyncCount;
		}

		set {
			if (!isHmdPresent)
				return;

			OVRPlugin.vsyncCount = value;
		}
	}

	/// <summary>
	/// Gets the current battery level.
	/// </summary>
	/// <returns><c>battery level in the range [0.0,1.0]</c>
	/// <param name="batteryLevel">Battery level.</param>
	public static float batteryLevel
	{
		get {
			if (!isHmdPresent)
				return 1f;

			return OVRPlugin.batteryLevel;
		}
	}

	/// <summary>
	/// Gets the current battery temperature.
	/// </summary>
	/// <returns><c>battery temperature in Celsius</c>
	/// <param name="batteryTemperature">Battery temperature.</param>
	public static float batteryTemperature
	{
		get {
			if (!isHmdPresent)
				return 0f;

			return OVRPlugin.batteryTemperature;
		}
	}

	/// <summary>
	/// Gets the current battery status.
	/// </summary>
	/// <returns><c>battery status</c>
	/// <param name="batteryStatus">Battery status.</param>
	public static int batteryStatus
	{
		get {
			if (!isHmdPresent)
				return -1;

			return (int)OVRPlugin.batteryStatus;
		}
	}

	/// <summary>
	/// Gets the current volume level.
	/// </summary>
	/// <returns><c>volume level in the range [0,1].</c>
	public static float volumeLevel
	{
		get {
			if (!isHmdPresent)
				return 0f;

			return OVRPlugin.systemVolume;
		}
	}

	/// <summary>
	/// Gets or sets the current CPU performance level (0-2). Lower performance levels save more power.
	/// </summary>
	public static int cpuLevel
	{
		get {
			if (!isHmdPresent)
				return 2;

			return OVRPlugin.cpuLevel;
		}

		set {
			if (!isHmdPresent)
				return;

			OVRPlugin.cpuLevel = value;
		}
	}

	/// <summary>
	/// Gets or sets the current GPU performance level (0-2). Lower performance levels save more power.
	/// </summary>
	public static int gpuLevel
	{
		get {
			if (!isHmdPresent)
				return 2;

			return OVRPlugin.gpuLevel;
		}

		set {
			if (!isHmdPresent)
				return;

			OVRPlugin.gpuLevel = value;
		}
	}

	/// <summary>
	/// If true, the CPU and GPU are currently throttled to save power and/or reduce the temperature.
	/// </summary>
	public static bool isPowerSavingActive
	{
		get {
			if (!isHmdPresent)
				return false;

			return OVRPlugin.powerSaving;
		}
	}

	/// <summary>
	/// Gets or sets the eye texture format.
	/// </summary>
	public static EyeTextureFormat eyeTextureFormat
	{
		get
		{
			return (OVRManager.EyeTextureFormat)OVRPlugin.GetDesiredEyeTextureFormat();
		}

		set
		{
			OVRPlugin.SetDesiredEyeTextureFormat((OVRPlugin.EyeTextureFormat)value);
		}
	}

	/// <summary>
	/// Gets if tiled-based multi-resolution technique is supported
	/// This feature is only supported on QCOMM-based Android devices
	/// </summary>
	public static bool tiledMultiResSupported
	{
		get
		{
			return OVRPlugin.tiledMultiResSupported;
		}
	}

	/// <summary>
	/// Gets or sets the tiled-based multi-resolution level
	/// This feature is only supported on QCOMM-based Android devices
	/// </summary>
	public static TiledMultiResLevel tiledMultiResLevel
	{
		get
		{
			if (!OVRPlugin.tiledMultiResSupported)
			{
				Debug.LogWarning("Tiled-based Multi-resolution feature is not supported");
			}
			return (TiledMultiResLevel)OVRPlugin.tiledMultiResLevel;
		}
		set
		{
			if (!OVRPlugin.tiledMultiResSupported)
			{
				Debug.LogWarning("Tiled-based Multi-resolution feature is not supported");
			}
			OVRPlugin.tiledMultiResLevel = (OVRPlugin.TiledMultiResLevel)value;
		}
	}

	/// <summary>
	/// Gets if the GPU Utility is supported
	/// This feature is only supported on QCOMM-based Android devices
	/// </summary>
	public static bool gpuUtilSupported
	{
		get
		{
			return OVRPlugin.gpuUtilSupported;
		}
	}

	/// <summary>
	/// Gets the GPU Utilised Level (0.0 - 1.0)
	/// This feature is only supported on QCOMM-based Android devices
	/// </summary>
	public static float gpuUtilLevel
	{
		get
		{
			if (!OVRPlugin.gpuUtilSupported)
			{
				Debug.LogWarning("GPU Util is not supported");
			}
			return OVRPlugin.gpuUtilLevel;
		}
	}


	[Header("Tracking")]
	[SerializeField]
	[Tooltip("Defines the current tracking origin type.")]
	private OVRManager.TrackingOrigin _trackingOriginType = OVRManager.TrackingOrigin.EyeLevel;
	/// <summary>
	/// Defines the current tracking origin type.
	/// </summary>
	public OVRManager.TrackingOrigin trackingOriginType
	{
		get {
			if (!isHmdPresent)
				return _trackingOriginType;

			return (OVRManager.TrackingOrigin)OVRPlugin.GetTrackingOriginType();
		}

		set {
			if (!isHmdPresent)
				return;

			if (OVRPlugin.SetTrackingOriginType((OVRPlugin.TrackingOrigin)value))
			{
				// Keep the field exposed in the Unity Editor synchronized with any changes.
				_trackingOriginType = value;
			}
		}
	}

	/// <summary>
	/// If true, head tracking will affect the position of each OVRCameraRig's cameras.
	/// </summary>
	[Tooltip("If true, head tracking will affect the position of each OVRCameraRig's cameras.")]
	public bool usePositionTracking = true;

	/// <summary>
	/// If true, head tracking will affect the rotation of each OVRCameraRig's cameras.
	/// </summary>
	[HideInInspector]
	public bool useRotationTracking = true;

	/// <summary>
	/// If true, the distance between the user's eyes will affect the position of each OVRCameraRig's cameras.
	/// </summary>
	[Tooltip("If true, the distance between the user's eyes will affect the position of each OVRCameraRig's cameras.")]
	public bool useIPDInPositionTracking = true;

	/// <summary>
	/// If true, each scene load will cause the head pose to reset.
	/// </summary>
	[Tooltip("If true, each scene load will cause the head pose to reset.")]
	public bool resetTrackerOnLoad = false;

	/// <summary>
	/// If true, the Reset View in the universal menu will cause the pose to be reset. This should generally be 
	/// enabled for applications with a stationary position in the virtual world and will allow the View Reset 
	/// command to place the person back to a predefined location (such as a cockpit seat). 
	/// Set this to false if you have a locomotion system because resetting the view would effectively teleport 
	/// the player to potentially invalid locations.
	/// </summary>
	[Tooltip("If true, the Reset View in the universal menu will cause the pose to be reset. This should generally be enabled for applications with a stationary position in the virtual world and will allow the View Reset command to place the person back to a predefined location (such as a cockpit seat). Set this to false if you have a locomotion system because resetting the view would effectively teleport the player to potentially invalid locations.")]
    public bool AllowRecenter = true;

    /// <summary>
	/// True if the current platform supports virtual reality.
	/// </summary>
	public bool isSupportedPlatform { get; private set; }

	private static bool _isUserPresentCached = false;
	private static bool _isUserPresent = false;
	private static bool _wasUserPresent = false;
	/// <summary>
	/// True if the user is currently wearing the display.
	/// </summary>
	public bool isUserPresent
	{
		get {
			if (!_isUserPresentCached)
			{
				_isUserPresentCached = true;
				_isUserPresent = OVRPlugin.userPresent;
			}

			return _isUserPresent;
		}

		private set {
			_isUserPresentCached = true;
			_isUserPresent = value;
		}
	}

	private static bool prevAudioOutIdIsCached = false;
	private static bool prevAudioInIdIsCached = false;
	private static string prevAudioOutId = string.Empty;
	private static string prevAudioInId = string.Empty;
	private static bool wasPositionTracked = false;

	public static System.Version utilitiesVersion
	{
		get { return OVRPlugin.wrapperVersion; }
	}

	public static System.Version pluginVersion
	{
		get { return OVRPlugin.version; }
	}

	public static System.Version sdkVersion
	{
		get { return OVRPlugin.nativeSDKVersion; }
	}

#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN
	private static bool prevEnableMixedReality = false;
	private static bool MixedRealityEnabledFromCmd()
	{
		var args = System.Environment.GetCommandLineArgs();
		for (int i = 0; i < args.Length; i++)
		{
			if (args[i].ToLower() == "-mixedreality")
				return true;
		}
		return false;
	}

	private static bool UseDirectCompositionFromCmd()
	{
		var args = System.Environment.GetCommandLineArgs();
		for (int i = 0; i < args.Length; i++)
		{
			if (args[i].ToLower() == "-directcomposition")
				return true;
		}
		return false;
	}

	private static bool UseExternalCompositionFromCmd()
	{
		var args = System.Environment.GetCommandLineArgs();
		for (int i = 0; i < args.Length; i++)
		{
			if (args[i].ToLower() == "-externalcomposition")
				return true;
		}
		return false;
	}

	private static bool CreateMixedRealityCaptureConfigurationFileFromCmd()
	{
		var args = System.Environment.GetCommandLineArgs();
		for (int i = 0; i < args.Length; i++)
		{
			if (args[i].ToLower() == "-create_mrc_config")
				return true;
		}
		return false;
	}

	private static bool LoadMixedRealityCaptureConfigurationFileFromCmd()
	{
		var args = System.Environment.GetCommandLineArgs();
		for (int i = 0; i < args.Length; i++)
		{
			if (args[i].ToLower() == "-load_mrc_config")
				return true;
		}
		return false;
	}
#endif

#region Unity Messages

	private void Awake()
	{
		// Only allow one instance at runtime.
		if (instance != null)
		{
			enabled = false;
			DestroyImmediate(this);
			return;
		}

		instance = this;

		Debug.Log("Unity v" + Application.unityVersion + ", " +
				  "Oculus Utilities v" + OVRPlugin.wrapperVersion + ", " +
				  "OVRPlugin v" + OVRPlugin.version + ", " +
				  "SDK v" + OVRPlugin.nativeSDKVersion + ".");

#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN
		var supportedTypes =
			UnityEngine.Rendering.GraphicsDeviceType.Direct3D11.ToString() + ", " +
			UnityEngine.Rendering.GraphicsDeviceType.Direct3D12.ToString();

		if (!supportedTypes.Contains(SystemInfo.graphicsDeviceType.ToString()))
			Debug.LogWarning("VR rendering requires one of the following device types: (" + supportedTypes + "). Your graphics device: " + SystemInfo.graphicsDeviceType.ToString());
#endif

		// Detect whether this platform is a supported platform
		RuntimePlatform currPlatform = Application.platform;
		isSupportedPlatform |= currPlatform == RuntimePlatform.Android;
		//isSupportedPlatform |= currPlatform == RuntimePlatform.LinuxPlayer;
		isSupportedPlatform |= currPlatform == RuntimePlatform.OSXEditor;
		isSupportedPlatform |= currPlatform == RuntimePlatform.OSXPlayer;
		isSupportedPlatform |= currPlatform == RuntimePlatform.WindowsEditor;
		isSupportedPlatform |= currPlatform == RuntimePlatform.WindowsPlayer;
		if (!isSupportedPlatform)
		{
			Debug.LogWarning("This platform is unsupported");
			return;
		}

#if UNITY_ANDROID && !UNITY_EDITOR
		// We want to set up our touchpad messaging system
		OVRTouchpad.Create();

		// Turn off chromatic aberration by default to save texture bandwidth.
		chromatic = false;
#endif

#if UNITY_STANDALONE_WIN && !UNITY_EDITOR
		enableMixedReality = false;		// we should never start the standalone game in MxR mode, unless the command-line parameter is provided
#endif

#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN
		bool loadMrcConfig = LoadMixedRealityCaptureConfigurationFileFromCmd();
		bool createMrcConfig = CreateMixedRealityCaptureConfigurationFileFromCmd();

		if (loadMrcConfig || createMrcConfig)
		{
			OVRMixedRealityCaptureSettings mrcSettings = ScriptableObject.CreateInstance<OVRMixedRealityCaptureSettings>();
			mrcSettings.ReadFrom(this);
			if (loadMrcConfig)
			{
				mrcSettings.CombineWithConfigurationFile();
				mrcSettings.ApplyTo(this);
			}
			if (createMrcConfig)
			{
				mrcSettings.WriteToConfigurationFile();
			}
			ScriptableObject.Destroy(mrcSettings);
		}

		if (MixedRealityEnabledFromCmd())
		{
			enableMixedReality = true;
		}

		if (enableMixedReality)
		{
			Debug.Log("OVR: Mixed Reality mode enabled");
			if (UseDirectCompositionFromCmd())
			{
				compositionMethod = CompositionMethod.Direct;
			}
			if (UseExternalCompositionFromCmd())
			{
				compositionMethod = CompositionMethod.External;
			}
			Debug.Log("OVR: CompositionMethod : " + compositionMethod);
		}
#endif

#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN
		if (enableAdaptiveResolution && !OVRManager.IsAdaptiveResSupportedByEngine())
		{
			enableAdaptiveResolution = false;
			UnityEngine.Debug.LogError("Your current Unity Engine " + Application.unityVersion + " might have issues to support adaptive resolution, please disable it under OVRManager");
		}
#endif

		Initialize();

		if (resetTrackerOnLoad)
			display.RecenterPose();

#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN
		// Force OcculusionMesh on all the time, you can change the value to false if you really need it be off for some reasons, 
		// be aware there are performance drops if you don't use occlusionMesh.
		OVRPlugin.occlusionMesh = true;
#endif
	}

#if UNITY_EDITOR
	private static bool _scriptsReloaded;

	[UnityEditor.Callbacks.DidReloadScripts]
	static void ScriptsReloaded()
	{
		_scriptsReloaded = true;
	}
#endif

	void Initialize()
	{
		if (display == null)
			display = new OVRDisplay();
		if (tracker == null)
			tracker = new OVRTracker();
		if (boundary == null)
			boundary = new OVRBoundary();
	}

#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN
	private bool suppressDisableMixedRealityBecauseOfNoMainCameraWarning = false;
#endif
	private void Update()
	{
#if UNITY_EDITOR
		if (_scriptsReloaded)
		{
			_scriptsReloaded = false;
			instance = this;
			Initialize();
		}
#endif

		if (OVRPlugin.shouldQuit)
			Application.Quit();

        if (AllowRecenter && OVRPlugin.shouldRecenter)
		{
			OVRManager.display.RecenterPose();
		}

		if (trackingOriginType != _trackingOriginType)
			trackingOriginType = _trackingOriginType;

		tracker.isEnabled = usePositionTracking;

		OVRPlugin.rotation = useRotationTracking;

		OVRPlugin.useIPDInPositionTracking = useIPDInPositionTracking;

		// Dispatch HMD events.

		isHmdPresent = OVRPlugin.hmdPresent;

		if (useRecommendedMSAALevel && QualitySettings.antiAliasing != display.recommendedMSAALevel)
		{
			Debug.Log("The current MSAA level is " + QualitySettings.antiAliasing +
			", but the recommended MSAA level is " + display.recommendedMSAALevel +
			". Switching to the recommended level.");

			QualitySettings.antiAliasing = display.recommendedMSAALevel;
		}

		if (_wasHmdPresent && !isHmdPresent)
		{
			try
			{
				if (HMDLost != null)
					HMDLost();
			}
			catch (Exception e)
			{
				Debug.LogError("Caught Exception: " + e);
			}
		}

		if (!_wasHmdPresent && isHmdPresent)
		{
			try
			{
				if (HMDAcquired != null)
					HMDAcquired();
			}
			catch (Exception e)
			{
				Debug.LogError("Caught Exception: " + e);
			}
		}

		_wasHmdPresent = isHmdPresent;

		// Dispatch HMD mounted events.

		isUserPresent = OVRPlugin.userPresent;

		if (_wasUserPresent && !isUserPresent)
		{
			try
			{
				if (HMDUnmounted != null)
					HMDUnmounted();
			}
			catch (Exception e)
			{
				Debug.LogError("Caught Exception: " + e);
			}
		}

		if (!_wasUserPresent && isUserPresent)
		{
			try
			{
				if (HMDMounted != null)
					HMDMounted();
			}
			catch (Exception e)
			{
				Debug.LogError("Caught Exception: " + e);
			}
		}

		_wasUserPresent = isUserPresent;

		// Dispatch VR Focus events.

		hasVrFocus = OVRPlugin.hasVrFocus;

		if (_hadVrFocus && !hasVrFocus)
		{
			try
			{
				if (VrFocusLost != null)
					VrFocusLost();
			}
			catch (Exception e)
			{
				Debug.LogError("Caught Exception: " + e);
			}
		}

		if (!_hadVrFocus && hasVrFocus)
		{
			try
			{
				if (VrFocusAcquired != null)
					VrFocusAcquired();
			}
			catch (Exception e)
			{
				Debug.LogError("Caught Exception: " + e);
			}
		}

		_hadVrFocus = hasVrFocus;

		// Dispatch VR Input events.

		bool hasInputFocus = OVRPlugin.hasInputFocus;

		if (_hadInputFocus && !hasInputFocus)
		{
			try
			{
				if (InputFocusLost != null)
					InputFocusLost();
			}
			catch (Exception e)
			{
				Debug.LogError("Caught Exception: " + e);
			}
		}

		if (!_hadInputFocus && hasInputFocus)
		{
			try
			{
				if (InputFocusAcquired != null)
					InputFocusAcquired();
			}
			catch (Exception e)
			{
				Debug.LogError("Caught Exception: " + e);
			}
		}

		_hadInputFocus = hasInputFocus;

		// Changing effective rendering resolution dynamically according performance
#if (UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN)

		if (enableAdaptiveResolution)
		{
#if UNITY_2017_2_OR_NEWER
			if (UnityEngine.XR.XRSettings.eyeTextureResolutionScale < maxRenderScale)
			{
				// Allocate renderScale to max to avoid re-allocation
				UnityEngine.XR.XRSettings.eyeTextureResolutionScale = maxRenderScale;
			}
			else
			{
				// Adjusting maxRenderScale in case app started with a larger renderScale value
				maxRenderScale = Mathf.Max(maxRenderScale, UnityEngine.XR.XRSettings.eyeTextureResolutionScale);
			}
			minRenderScale = Mathf.Min(minRenderScale, maxRenderScale);
			float minViewportScale = minRenderScale / UnityEngine.XR.XRSettings.eyeTextureResolutionScale;
			float recommendedViewportScale = OVRPlugin.GetEyeRecommendedResolutionScale() / UnityEngine.XR.XRSettings.eyeTextureResolutionScale;
			recommendedViewportScale = Mathf.Clamp(recommendedViewportScale, minViewportScale, 1.0f);
			UnityEngine.XR.XRSettings.renderViewportScale = recommendedViewportScale;
#else
			if (UnityEngine.VR.VRSettings.renderScale < maxRenderScale)
			{
				// Allocate renderScale to max to avoid re-allocation
				UnityEngine.VR.VRSettings.renderScale = maxRenderScale;
			}
			else
			{
				// Adjusting maxRenderScale in case app started with a larger renderScale value
				maxRenderScale = Mathf.Max(maxRenderScale, UnityEngine.VR.VRSettings.renderScale);
			}
			minRenderScale = Mathf.Min(minRenderScale, maxRenderScale);
			float minViewportScale = minRenderScale / UnityEngine.VR.VRSettings.renderScale;
			float recommendedViewportScale = OVRPlugin.GetEyeRecommendedResolutionScale() / UnityEngine.VR.VRSettings.renderScale;
			recommendedViewportScale = Mathf.Clamp(recommendedViewportScale, minViewportScale, 1.0f);
			UnityEngine.VR.VRSettings.renderViewportScale = recommendedViewportScale;
#endif
		}
#endif

		// Dispatch Audio Device events.

		string audioOutId = OVRPlugin.audioOutId;
		if (!prevAudioOutIdIsCached)
		{
			prevAudioOutId = audioOutId;
			prevAudioOutIdIsCached = true;
		}
		else if (audioOutId != prevAudioOutId)
		{
			try
			{
				if (AudioOutChanged != null)
					AudioOutChanged();
			}
			catch (Exception e)
			{
				Debug.LogError("Caught Exception: " + e);
			}

			prevAudioOutId = audioOutId;
		}

		string audioInId = OVRPlugin.audioInId;
		if (!prevAudioInIdIsCached)
		{
			prevAudioInId = audioInId;
			prevAudioInIdIsCached = true;
		}
		else if (audioInId != prevAudioInId)
		{
			try
			{
				if (AudioInChanged != null)
					AudioInChanged();
			}
			catch (Exception e)
			{
				Debug.LogError("Caught Exception: " + e);
			}

			prevAudioInId = audioInId;
		}

		// Dispatch tracking events.

		if (wasPositionTracked && !tracker.isPositionTracked)
		{
			try
			{
				if (TrackingLost != null)
					TrackingLost();
			}
			catch (Exception e)
			{
				Debug.LogError("Caught Exception: " + e);
			}
		}

		if (!wasPositionTracked && tracker.isPositionTracked)
		{
			try
			{
				if (TrackingAcquired != null)
					TrackingAcquired();
			}
			catch (Exception e)
			{
				Debug.LogError("Caught Exception: " + e);
			}
		}

		wasPositionTracked = tracker.isPositionTracked;

		display.Update();
		OVRInput.Update();

#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN
		if (enableMixedReality || prevEnableMixedReality)
		{
			Camera mainCamera = FindMainCamera();
			if (Camera.main != null)
			{
				suppressDisableMixedRealityBecauseOfNoMainCameraWarning = false;

				if (enableMixedReality)
				{
					OVRMixedReality.Update(this.gameObject, mainCamera, compositionMethod, useDynamicLighting, capturingCameraDevice, depthQuality);
				}

				if (prevEnableMixedReality && !enableMixedReality)
				{
					OVRMixedReality.Cleanup();
				}

				prevEnableMixedReality = enableMixedReality;
			}
			else
			{
				if (!suppressDisableMixedRealityBecauseOfNoMainCameraWarning)
				{
					Debug.LogWarning("Main Camera is not set, Mixed Reality disabled");
					suppressDisableMixedRealityBecauseOfNoMainCameraWarning = true;
				}
			}
		}
#endif
	}

	private bool multipleMainCameraWarningPresented = false;
	private Camera FindMainCamera()
	{
		GameObject[] objects = GameObject.FindGameObjectsWithTag("MainCamera");
		List<Camera> cameras = new List<Camera>(4);
		foreach (GameObject obj in objects)
		{
			Camera camera = obj.GetComponent<Camera>();
			if (camera != null && camera.enabled)
			{
				OVRCameraRig cameraRig = camera.GetComponentInParent<OVRCameraRig>();
				if (cameraRig != null && cameraRig.trackingSpace != null)
				{
					cameras.Add(camera);
				}
			}
		}
		if (cameras.Count == 0)
		{
			return Camera.main;		// pick one of the cameras which tagged as "MainCamera"
		}
		else if (cameras.Count == 1)
		{
			return cameras[0];
		}
		else
		{
			if (!multipleMainCameraWarningPresented)
			{
				Debug.LogWarning("Multiple MainCamera found. Assume the real MainCamera is the camera with the least depth");
				multipleMainCameraWarningPresented = true;
			}
			// return the camera with least depth
			cameras.Sort((Camera c0, Camera c1) => { return c0.depth < c1.depth ? -1 : (c0.depth > c1.depth ? 1 : 0); });
			return cameras[0];
		}
	}

	private void OnDisable()
	{
#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN
		OVRMixedReality.Cleanup();
#endif
	}

	private void LateUpdate()
	{
		OVRHaptics.Process();
	}

	private void FixedUpdate()
	{
		OVRInput.FixedUpdate();
	}

	/// <summary>
	/// Leaves the application/game and returns to the launcher/dashboard
	/// </summary>
	public void ReturnToLauncher()
	{
		// show the platform UI quit prompt
		OVRManager.PlatformUIConfirmQuit();
	}

#endregion

	public static void PlatformUIConfirmQuit()
	{
		if (!isHmdPresent)
			return;

		OVRPlugin.ShowUI(OVRPlugin.PlatformUI.ConfirmQuit);
	}
}
