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

Filename    :   OculusWorldDemo.cpp
Content     :   First-person view test application for Oculus Rift
Created     :   October 4, 2012
Authors     :   Michael Antonov, Andrew Reisse, Steve LaValle
				Peter Hoff, Dan Goodman, Bryan Croteau

Copyright   :   Copyright 2012 Oculus VR, Inc. All Rights reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
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.

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

#include "OVR.h"

#include "../CommonSrc/Platform/Platform_Default.h"
#include "../CommonSrc/Render/Render_Device.h"
#include "../CommonSrc/Render/Render_XmlSceneLoader.h"
#include "../CommonSrc/Render/Render_FontEmbed_DejaVu48.h"
#include "../CommonSrc/Platform/Gamepad.h"

#include <Kernel/OVR_SysFile.h>
#include <Kernel/OVR_Log.h>
#include <Kernel/OVR_Timer.h>

#include "Player.h"

// Filename to be loaded by default, searching specified paths.
#define WORLDDEMO_ASSET_FILE  "Tuscany.xml"
#define WORLDDEMO_ASSET_PATH1 "Assets/Tuscany/"
#define WORLDDEMO_ASSET_PATH2 "../Assets/Tuscany/"
// This path allows the shortcut to work.
#define WORLDDEMO_ASSET_PATH3 "Samples/OculusWorldDemo/Assets/Tuscany/"


using namespace OVR;
using namespace OVR::Platform;
using namespace OVR::Render;

//-------------------------------------------------------------------------------------
// ***** OculusWorldDemo Description

// This app renders a simple flat-shaded room allowing the user to move along the
// floor and look around with an HMD, mouse and keyboard. The following keys work:
//
//  'W', 'S', 'A', 'D' and Arrow Keys - Move forward, back; strafe left/right.
//  F1 - No stereo, no distortion.
//  F2 - Stereo, no distortion.
//  F3 - Stereo and distortion.
//  F4 - Toggle MSAA.
//  F9 - Cycle through fullscreen and windowed modes. Necessary for previewing content with Rift.
//
// Important Oculus-specific logic can be found at following locations:
//
//  OculusWorldDemoApp::OnStartup - This function will initialize OVR::DeviceManager and HMD,
//									creating SensorDevice and attaching it to SensorFusion.
//									This needs to be done before obtaining sensor data.
//
//  OculusWorldDemoApp::OnIdle    - Here we poll SensorFusion for orientation, apply it
//									to the scene and handle movement.
//									Stereo rendering is also done here, by delegating to
//									to Render function for each eye.
//

//-------------------------------------------------------------------------------------
// ***** OculusWorldDemo Application class

// An instance of this class is created on application startup (main/WinMain).
// It then works as follows:
//  - Graphics and HMD setup is done OculusWorldDemoApp::OnStartup(). This function
//    also creates the room model from Slab declarations.
//  - Per-frame processing is done in OnIdle(). This function processes
//    sensor and movement input and then renders the frame.
//  - Additional input processing is done in OnMouse, OnKey.

class OculusWorldDemoApp : public Application, public MessageHandler
{
public:
    OculusWorldDemoApp();
    ~OculusWorldDemoApp();

    virtual int  OnStartup(int argc, const char** argv);
    virtual void OnIdle();

    virtual void OnMouseMove(int x, int y, int modifiers);
    virtual void OnKey(OVR::KeyCode key, int chr, bool down, int modifiers);
    virtual void OnResize(int width, int height);

    virtual void OnMessage(const Message& msg);

    void         Render(const StereoEyeParams& stereo);

    // Sets temporarily displayed message for adjustments
    void         SetAdjustMessage(const char* format, ...);
    // Overrides current timeout, in seconds (not the future default value);
    // intended to be called right after SetAdjustMessage.
    void         SetAdjustMessageTimeout(float timeout);

    // Stereo setting adjustment functions.
    // Called with deltaTime when relevant key is held.
    void         AdjustFov(float dt);
    void         AdjustAspect(float dt);
    void         AdjustIPD(float dt);
    void         AdjustEyeHeight(float dt);

    void         AdjustMotionPrediction(float dt);

    void         AdjustDistortion(float dt, int kIndex, const char* label);
    void         AdjustDistortionK0(float dt)  { AdjustDistortion(dt, 0, "K0"); }
    void         AdjustDistortionK1(float dt)  { AdjustDistortion(dt, 1, "K1"); }
    void         AdjustDistortionK2(float dt)  { AdjustDistortion(dt, 2, "K2"); }
    void         AdjustDistortionK3(float dt)  { AdjustDistortion(dt, 3, "K3"); }

	void		 AdjustDistortion(float val, int kIndex);
	void		 AdjustEsd(float val);

    // Adds room model to scene.
    void         PopulateScene(const char* fileName);
    void         PopulatePreloadScene();
    void		 ClearScene();

    // Magnetometer calibration procedure
    void         UpdateManualMagCalibration();

protected:
    RenderDevice*       pRender;
    RendererParams      RenderParams;
    int                 Width, Height;
    int                 Screen;
    int                 FirstScreenInCycle;

    // *** Oculus HMD Variables
    Ptr<DeviceManager>  pManager;
    Ptr<SensorDevice>   pSensor;
    Ptr<HMDDevice>      pHMD;
    Ptr<Profile>        pUserProfile;
    SensorFusion        SFusion;
    HMDInfo             TheHMDInfo;

    Ptr<LatencyTestDevice>  pLatencyTester;
    Util::LatencyTest   LatencyUtil;

    double              LastUpdate;
    int                 FPS;
    int                 FrameCounter;
    double              NextFPSUpdate;

    Array<Ptr<CollisionModel> > CollisionModels;
    Array<Ptr<CollisionModel> > GroundCollisionModels;

    // Loading process displays screenshot in first frame
    // and then proceeds to load until finished.
    enum LoadingStateType
    {
        LoadingState_Frame0,
        LoadingState_DoLoad,
        LoadingState_Finished
    };

	// Player
    Player				ThePlayer;
    Matrix4f            View;
    Scene               MainScene;
    Scene               LoadingScene;
    Scene               GridScene;
    Scene               YawMarkGreenScene;
    Scene               YawMarkRedScene;
    Scene               YawLinesScene;

    LoadingStateType    LoadingState;

    Ptr<ShaderFill>     LitSolid, LitTextures[4];

    // Stereo view parameters.
    StereoConfig        SConfig;
    PostProcessType     PostProcess;

    // LOD
    String	            MainFilePath;
    Array<String>       LODFilePaths;
    int					ConsecutiveLowFPSFrames;
    int					CurrentLODFileIndex;

    float               DistortionK0;
    float               DistortionK1;
    float               DistortionK2;
    float               DistortionK3;

    String              AdjustMessage;
    double              AdjustMessageTimeout;

    // Saved distortion state.
    float               SavedK0, SavedK1, SavedK2, SavedK3;
    float               SavedESD, SavedAspect, SavedEyeDistance;

    // Allows toggling color around distortion.
    Color               DistortionClearColor;

    // Stereo settings adjustment state.
    typedef void (OculusWorldDemoApp::*AdjustFuncType)(float);
    bool                ShiftDown;
    AdjustFuncType      pAdjustFunc;
    float               AdjustDirection;

    enum SceneRenderMode
    {
        Scene_World,
        Scene_Grid,
        Scene_Both,
        Scene_YawView
    };
    SceneRenderMode    SceneMode;


    enum TextScreen
    {
        Text_None,
        Text_Orientation,
        Text_Config,
        Text_Help,
        Text_Count
    };
    TextScreen          TextScreen;

    struct DeviceStatusNotificationDesc
    {
        DeviceHandle    Handle;
        MessageType     Action;

        DeviceStatusNotificationDesc():Action(Message_None) {}
        DeviceStatusNotificationDesc(MessageType mt, const DeviceHandle& dev) 
            : Handle(dev), Action(mt) {}
    };
    Array<DeviceStatusNotificationDesc> DeviceStatusNotificationsQueue; 


    Model* CreateModel(Vector3f pos, struct SlabModel* sm);
    Model* CreateBoundingModel(CollisionModel &cm);
    void PopulateLODFileNames();
    void DropLOD();
    void RaiseLOD();
    void CycleDisplay();
    void GamepadStateChanged(const GamepadState& pad);
};

//-------------------------------------------------------------------------------------

OculusWorldDemoApp::OculusWorldDemoApp()
    : pRender(0),
      LastUpdate(0),
      LoadingState(LoadingState_Frame0),
      // Initial location
      SConfig(),
      PostProcess(PostProcess_Distortion),
      DistortionClearColor(0, 0, 0),

      ShiftDown(false),
      pAdjustFunc(0),
      AdjustDirection(1.0f),
      SceneMode(Scene_World),
      TextScreen(Text_None)
{
    Width  = 1280;
    Height = 800;
    Screen = 0;
    FirstScreenInCycle = 0;

    FPS = 0;
    FrameCounter = 0;
    NextFPSUpdate = 0;

    ConsecutiveLowFPSFrames = 0;
    CurrentLODFileIndex = 0;

    AdjustMessageTimeout = 0;
}

OculusWorldDemoApp::~OculusWorldDemoApp()
{
    RemoveHandlerFromDevices();

    if(DejaVu.fill)
    {
        DejaVu.fill->Release();
    }
    pLatencyTester.Clear();
    pSensor.Clear();
    pHMD.Clear();
    
	CollisionModels.ClearAndRelease();
	GroundCollisionModels.ClearAndRelease();
}

int OculusWorldDemoApp::OnStartup(int argc, const char** argv)
{

    // *** Oculus HMD & Sensor Initialization

    // Create DeviceManager and first available HMDDevice from it.
    // Sensor object is created from the HMD, to ensure that it is on the
    // correct device.

    pManager = *DeviceManager::Create();

    // We'll handle it's messages in this case.
    pManager->SetMessageHandler(this);
    

    pHMD = *pManager->EnumerateDevices<HMDDevice>().CreateDevice();
    if (pHMD)
    {
        pSensor = *pHMD->GetSensor();

        // This will initialize HMDInfo with information about configured IPD,
        // screen size and other variables needed for correct projection.
        // We pass HMD DisplayDeviceName into the renderer to select the
        // correct monitor in full-screen mode.
        if(pHMD->GetDeviceInfo(&TheHMDInfo))
        {
            //RenderParams.MonitorName = hmd.DisplayDeviceName;
            SConfig.SetHMDInfo(TheHMDInfo);
        }

        // Retrieve relevant profile settings. 
        pUserProfile = pHMD->GetProfile();
        if (pUserProfile)
        {
            ThePlayer.UserEyeHeight = pUserProfile->GetEyeHeight();
            ThePlayer.EyePos.y = ThePlayer.UserEyeHeight;
        }
    }
    else
    {
        // If we didn't detect an HMD, try to create the sensor directly.
        // This is useful for debugging sensor interaction; it is not needed in
        // a shipping app.
        pSensor = *pManager->EnumerateDevices<SensorDevice>().CreateDevice();
    }
        
    // Create the Latency Tester device and assign it to the LatencyTesterUtil object.
    pLatencyTester = *pManager->EnumerateDevices<LatencyTestDevice>().CreateDevice();
    if (pLatencyTester)
    {
        LatencyUtil.SetDevice(pLatencyTester);
    }
    // Make the user aware which devices are present.
    if(pHMD == NULL && pSensor == NULL)
    {
        SetAdjustMessage("---------------------------------\nNO HMD DETECTED\nNO SENSOR DETECTED\n---------------------------------");
    }
    else if(pHMD == NULL)
    {
        SetAdjustMessage("----------------------------\nNO HMD DETECTED\n----------------------------");
    }
    else if(pSensor == NULL)
    {
        SetAdjustMessage("---------------------------------\nNO SENSOR DETECTED\n---------------------------------");
    }
    else
    {
        SetAdjustMessage("--------------------------------------------\n"
                         "Press F9 for Full-Screen on Rift\n"
                         "--------------------------------------------");
    }

    // First message should be extra-long.
    SetAdjustMessageTimeout(10.0f);


    if(TheHMDInfo.HResolution > 0)
    {
        Width  = TheHMDInfo.HResolution;
        Height = TheHMDInfo.VResolution;
    }

    if(!pPlatform->SetupWindow(Width, Height))
    {
        return 1;
    }

    String Title = "Oculus World Demo";
    if(TheHMDInfo.ProductName[0])
    {
        Title += " : ";
        Title += TheHMDInfo.ProductName;
    }
    pPlatform->SetWindowTitle(Title);

    // Report relative mouse motion in OnMouseMove
    pPlatform->SetMouseMode(Mouse_Relative);
    
    if(pSensor)
    {
        // We need to attach sensor to SensorFusion object for it to receive
        // body frame messages and update orientation. SFusion.GetOrientation()
        // is used in OnIdle() to orient the view.
        SFusion.AttachToSensor(pSensor);

        SFusion.SetDelegateMessageHandler(this);

        SFusion.SetPredictionEnabled(true);
    }


    // *** Initialize Rendering

    const char* graphics = "d3d11";

    // Select renderer based on command line arguments.
    for(int i = 1; i < argc; i++)
    {
        if(!strcmp(argv[i], "-r") && i < argc - 1)
        {
            graphics = argv[i + 1];
        }
        else if(!strcmp(argv[i], "-fs"))
        {
            RenderParams.Fullscreen = true;
        }
    }

    // Enable multi-sampling by default.
    RenderParams.Multisample = 4;
    pRender = pPlatform->SetupGraphics(OVR_DEFAULT_RENDER_DEVICE_SET,
                                       graphics, RenderParams);



    // *** Configure Stereo settings.

    SConfig.SetFullViewport(Viewport(0, 0, Width, Height));
    SConfig.SetStereoMode(Stereo_LeftRight_Multipass);

    // Configure proper Distortion Fit.
    // For 7" screen, fit to touch left side of the view, leaving a bit of
    // invisible screen on the top (saves on rendering cost).
    // For smaller screens (5.5"), fit to the top.
    if (TheHMDInfo.HScreenSize > 0.0f)
    {
        if (TheHMDInfo.HScreenSize > 0.140f)  // 7"
            SConfig.SetDistortionFitPointVP(-1.0f, 0.0f);        
        else        
            SConfig.SetDistortionFitPointVP(0.0f, 1.0f);        
    }

    pRender->SetSceneRenderScale(SConfig.GetDistortionScale());
    //pRender->SetSceneRenderScale(1.0f);

    SConfig.Set2DAreaFov(DegreeToRad(85.0f));


    // *** Identify Scene File & Prepare for Loading
   
    // This creates lights and models.
    if (argc == 2)
    {        
        MainFilePath = argv[1];
        PopulateLODFileNames();
    }
    else
    {
        fprintf(stderr, "Usage: OculusWorldDemo [input XML]\n");
        MainFilePath = WORLDDEMO_ASSET_FILE;	
    }

    // Try to modify path for correctness in case specified file is not found.
    if (!SysFile(MainFilePath).IsValid())
    {
        String prefixPath1(pPlatform->GetContentDirectory() + "/" + WORLDDEMO_ASSET_PATH1),
               prefixPath2(WORLDDEMO_ASSET_PATH2),
               prefixPath3(WORLDDEMO_ASSET_PATH3);
        if (SysFile(prefixPath1 + MainFilePath).IsValid())
            MainFilePath = prefixPath1 + MainFilePath;
        else if (SysFile(prefixPath2 + MainFilePath).IsValid())
            MainFilePath = prefixPath2 + MainFilePath;
        else if (SysFile(prefixPath3 + MainFilePath).IsValid())
            MainFilePath = prefixPath3 + MainFilePath;
    }

    PopulatePreloadScene();

    LastUpdate = pPlatform->GetAppTime();
	//pPlatform->PlayMusicFile(L"Loop.wav");
    
    return 0;
}

void OculusWorldDemoApp::OnMessage(const Message& msg)
{
    if (msg.Type == Message_DeviceAdded || msg.Type == Message_DeviceRemoved)
    {
        if (msg.pDevice == pManager)
        {
            const MessageDeviceStatus& statusMsg =
                static_cast<const MessageDeviceStatus&>(msg);

            { // limit the scope of the lock
                Lock::Locker lock(pManager->GetHandlerLock());
                DeviceStatusNotificationsQueue.PushBack(
                    DeviceStatusNotificationDesc(statusMsg.Type, statusMsg.Handle));
            }

            switch (statusMsg.Type)
            {
                case OVR::Message_DeviceAdded:
                    LogText("DeviceManager reported device added.\n");
                    break;
                
                case OVR::Message_DeviceRemoved:
                    LogText("DeviceManager reported device removed.\n");
                    break;
                
                default: OVR_ASSERT(0); // unexpected type
            }
        }
    }
}

void OculusWorldDemoApp::OnResize(int width, int height)
{
    Width  = width;
    Height = height;
    SConfig.SetFullViewport(Viewport(0, 0, Width, Height));
}

void OculusWorldDemoApp::OnMouseMove(int x, int y, int modifiers)
{
    if(modifiers & Mod_MouseRelative)
    {
        // Get Delta
        int dx = x, dy = y;

        const float maxPitch = ((3.1415f / 2) * 0.98f);

        // Apply to rotation. Subtract for right body frame rotation,
        // since yaw rotation is positive CCW when looking down on XZ plane.
        ThePlayer.EyeYaw   -= (Sensitivity * dx) / 360.0f;

        if(!pSensor)
        {
            ThePlayer.EyePitch -= (Sensitivity * dy) / 360.0f;

            if(ThePlayer.EyePitch > maxPitch)
            {
                ThePlayer.EyePitch = maxPitch;
            }
            if(ThePlayer.EyePitch < -maxPitch)
            {
                ThePlayer.EyePitch = -maxPitch;
            }
        }
    }
}


void OculusWorldDemoApp::OnKey(OVR::KeyCode key, int chr, bool down, int modifiers)
{
    OVR_UNUSED(chr);

    switch(key)
    {
    case Key_Q:
        if (down && (modifiers & Mod_Control))
        {
            pPlatform->Exit(0);
        }
        break;

        // Handle player movement keys.
        // We just update movement state here, while the actual translation is done in OnIdle()
        // based on time.
    case Key_W:
        ThePlayer.MoveForward = down ? (ThePlayer.MoveForward | 1) : (ThePlayer.MoveForward & ~1);
        break;
    case Key_S:
        ThePlayer.MoveBack    = down ? (ThePlayer.MoveBack    | 1) : (ThePlayer.MoveBack    & ~1);
        break;
    case Key_A:
        ThePlayer.MoveLeft    = down ? (ThePlayer.MoveLeft    | 1) : (ThePlayer.MoveLeft    & ~1);
        break;
    case Key_D:
        ThePlayer.MoveRight   = down ? (ThePlayer.MoveRight   | 1) : (ThePlayer.MoveRight   & ~1);
        break;
    case Key_Up:
        ThePlayer.MoveForward = down ? (ThePlayer.MoveForward | 2) : (ThePlayer.MoveForward & ~2);
        break;
    case Key_Down:
        ThePlayer.MoveBack    = down ? (ThePlayer.MoveBack    | 2) : (ThePlayer.MoveBack    & ~2);
        break;
    case Key_Left:
        ThePlayer.MoveLeft    = down ? (ThePlayer.MoveLeft    | 2) : (ThePlayer.MoveLeft    & ~2);
        break;
    case Key_Right:
        ThePlayer.MoveRight   = down ? (ThePlayer.MoveRight   | 2) : (ThePlayer.MoveRight   & ~2);
        break;

    case Key_Minus:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustEyeHeight  : 0;
        AdjustDirection = -1;
        break;
    case Key_Equal:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustEyeHeight  : 0;
        AdjustDirection = 1;
        break;

    case Key_B:
        if (down)
        {
            if(SConfig.GetDistortionScale() == 1.0f)
            {
                if(SConfig.GetHMDInfo().HScreenSize > 0.140f)  // 7"
                {
                    SConfig.SetDistortionFitPointVP(-1.0f, 0.0f);
                }
                else
                {
                 SConfig.SetDistortionFitPointVP(0.0f, 1.0f);
                }
            }
            else
            {
                // No fitting; scale == 1.0.
                SConfig.SetDistortionFitPointVP(0, 0);
            }
        }
        break;

    // Support toggling background color for distortion so that we can see
    // the effect on the periphery.
    case Key_V:
        if (down)
        {
            if(DistortionClearColor.B == 0)
            {
                DistortionClearColor = Color(0, 128, 255);
            }
            else
            {
                DistortionClearColor = Color(0, 0, 0);
            }

            pRender->SetDistortionClearColor(DistortionClearColor);
        }
        break;


    case Key_F1:
        SConfig.SetStereoMode(Stereo_None);
        PostProcess = PostProcess_None;
        SetAdjustMessage("StereoMode: None");
        break;
    case Key_F2:
        SConfig.SetStereoMode(Stereo_LeftRight_Multipass);
        PostProcess = PostProcess_None;
        SetAdjustMessage("StereoMode: Stereo + No Distortion");
        break;
    case Key_F3:
        SConfig.SetStereoMode(Stereo_LeftRight_Multipass);
        PostProcess = PostProcess_Distortion;
        SetAdjustMessage("StereoMode: Stereo + Distortion");
        break;

    case Key_R:
        SFusion.Reset();
        SetAdjustMessage("Sensor Fusion Reset");
        break;

    case Key_Space:
        if (!down)
        {
            TextScreen = (enum TextScreen)((TextScreen + 1) % Text_Count);
        }
        break;

    case Key_F4:
        if (!down)
        {
			RenderParams = pRender->GetParams();
            RenderParams.Multisample = RenderParams.Multisample > 1 ? 1 : 4;
            pRender->SetParams(RenderParams);
            if(RenderParams.Multisample > 1)
            {
                SetAdjustMessage("Multisampling On");
            }
            else
            {
                SetAdjustMessage("Multisampling Off");
            }
        }
        break;
    case Key_F9:
#ifndef OVR_OS_LINUX    // On Linux F9 does the same as F11.
        if (!down)
        {
            CycleDisplay();
        }
        break;
#endif
#ifdef OVR_OS_MAC
    case Key_F10:  // F11 is reserved on Mac
#else
    case Key_F11:
#endif
        if (!down)
        {
            RenderParams = pRender->GetParams();
            RenderParams.Display = DisplayId(SConfig.GetHMDInfo().DisplayDeviceName,SConfig.GetHMDInfo().DisplayId);
            pRender->SetParams(RenderParams);

            pPlatform->SetMouseMode(Mouse_Normal);            
            pPlatform->SetFullscreen(RenderParams, pRender->IsFullscreen() ? Display_Window : Display_FakeFullscreen);
            pPlatform->SetMouseMode(Mouse_Relative); // Avoid mode world rotation jump.
            // If using an HMD, enable post-process (for distortion) and stereo.
            if(RenderParams.IsDisplaySet() && pRender->IsFullscreen())
            {
                SConfig.SetStereoMode(Stereo_LeftRight_Multipass);
                PostProcess = PostProcess_Distortion;
            }
        }
        break;

    case Key_Escape:
        if(!down)
        {
            // switch to primary screen windowed mode
            pPlatform->SetFullscreen(RenderParams, Display_Window);
            RenderParams.Display = pPlatform->GetDisplay(0);
            pRender->SetParams(RenderParams);
            Screen = 0;
        }
        break;

        // Stereo adjustments.
    case Key_BracketLeft:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustFov    : 0;
        AdjustDirection = 1;
        break;
    case Key_BracketRight:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustFov    : 0;
        AdjustDirection = -1;
        break;

    case Key_Insert:
    case Key_Num0:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustIPD    : 0;
        AdjustDirection = 1;
        break;
    case Key_Delete:
    case Key_Num9:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustIPD    : 0;
        AdjustDirection = -1;
        break;

    case Key_PageUp:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustAspect : 0;
        AdjustDirection = 1;
        break;
    case Key_PageDown:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustAspect : 0;
        AdjustDirection = -1;
        break;

        // Distortion correction adjustments
    case Key_H:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustDistortionK0 : NULL;
        AdjustDirection = -1;
        break;
    case Key_Y:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustDistortionK0 : NULL;
        AdjustDirection = 1;
        break;
    case Key_J:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustDistortionK1 : NULL;
        AdjustDirection = -1;
        break;
    case Key_U:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustDistortionK1 : NULL;
        AdjustDirection = 1;
        break;
    case Key_K:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustDistortionK2 : NULL;
        AdjustDirection = -1;
        break;
    case Key_I:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustDistortionK2 : NULL;
        AdjustDirection = 1;
        break;
    case Key_L:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustDistortionK3 : NULL;
        AdjustDirection = -1;
        break;
    case Key_O:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustDistortionK3 : NULL;
        AdjustDirection = 1;
        break;

    case Key_Tab:
        if (down)
        {
            float t0      = SConfig.GetDistortionK(0),
                  t1      = SConfig.GetDistortionK(1),
                  t2      = SConfig.GetDistortionK(2),
                  t3      = SConfig.GetDistortionK(3);
            float tESD    = SConfig.GetEyeToScreenDistance(),
                  taspect = SConfig.GetAspectMultiplier(),
                  tipd    = SConfig.GetIPD();

            if(SavedK0 > 0.0f)
            {
				SConfig.SetDistortionK(0, SavedK0);
				SConfig.SetDistortionK(1, SavedK1);
				SConfig.SetDistortionK(2, SavedK2);
				SConfig.SetDistortionK(3, SavedK3);
				SConfig.SetEyeToScreenDistance(SavedESD);
				SConfig.SetAspectMultiplier(SavedAspect);
				SConfig.SetIPD(SavedEyeDistance);

				if ( ShiftDown )
				{
					// Swap saved and current values. Good for doing direct comparisons.
					SetAdjustMessage("Swapped current and saved. New settings:\n"
									 "ESD:\t120 %.3f\t350 Eye:\t490 %.3f\n"
									 "K0: \t120 %.4f\t350 K2: \t490 %.4f\n"
									 "K1: \t120 %.4f\t350 K3: \t490 %.4f\n",
									 SavedESD, SavedEyeDistance,
									 SavedK0, SavedK2,
									 SavedK1, SavedK3);
					SavedK0 = t0;
					SavedK1 = t1;
					SavedK2 = t2;
					SavedK3 = t3;
					SavedESD = tESD;
					SavedAspect = taspect;
					SavedEyeDistance = tipd;
				}
				else
				{
					SetAdjustMessage("Restored:\n"
									 "ESD:\t120 %.3f\t350 Eye:\t490 %.3f\n"
									 "K0: \t120 %.4f\t350 K2: \t490 %.4f\n"
									 "K1: \t120 %.4f\t350 K3: \t490 %.4f\n",
									 SavedESD, SavedEyeDistance,
									 SavedK0, SavedK2,
									 SavedK1, SavedK3);
				}
            }
            else
            {
                SetAdjustMessage("Setting Saved");
				SavedK0 = t0;
				SavedK1 = t1;
				SavedK2 = t2;
				SavedK3 = t3;
				SavedESD = tESD;
				SavedAspect = taspect;
				SavedEyeDistance = tipd;
            }

        }
        break; 
 
    case Key_G:
        if (down)
        {
            if(SceneMode == Scene_World)
            {
                SceneMode = Scene_Grid;
                SetAdjustMessage("Grid Only");
            }
            else if(SceneMode == Scene_Grid)
            {
                SceneMode = Scene_Both;
                SetAdjustMessage("Grid Overlay");
            }
            else if(SceneMode == Scene_Both)
            {
                SceneMode = Scene_World;
                SetAdjustMessage("Grid Off");
            }
        }
        break;

        // Holding down Shift key accelerates adjustment velocity.
    case Key_Shift:
        ShiftDown = down;
        break;

        // Reset the camera position in case we get stuck
    case Key_T:
        ThePlayer.EyePos = Vector3f(10.0f, ThePlayer.UserEyeHeight, 10.0f);
        break;

    case Key_F5:
        if (!down)
        {
            UPInt numNodes = MainScene.Models.GetSize();
            for(UPInt i = 0; i < numNodes; i++)
            {
                Ptr<OVR::Render::Model> nodePtr = MainScene.Models[i];
                Render::Model*          pNode = nodePtr.GetPtr();
                if(pNode->IsCollisionModel)
                {
                    pNode->Visible = !pNode->Visible;
                }
            }
        }
        break;

    case Key_N:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustMotionPrediction : NULL;
        AdjustDirection = -1;
        break;

    case Key_M:
        pAdjustFunc = down ? &OculusWorldDemoApp::AdjustMotionPrediction : NULL;
        AdjustDirection = 1;
        break;

/*
    case Key_N:
        RaiseLOD();
        break;
    case Key_M:
        DropLOD();
        break;
*/

        // Cycle through drift correction options
    case Key_Z:
        if (down)
        {
            if (SFusion.IsYawCorrectionEnabled())
            {
                SFusion.SetGravityEnabled(false);
                SFusion.SetYawCorrectionEnabled(false);
            }
            else if (SFusion.IsGravityEnabled())
            {
                SFusion.SetYawCorrectionEnabled(true);
            }
            else
            {
                SFusion.SetGravityEnabled(true);
            }
            SetAdjustMessage("Tilt Correction %s\nYaw Correction %s", 
                SFusion.IsGravityEnabled() ? "On" : "Off",
                SFusion.IsYawCorrectionEnabled() ? "On" : "Off");
        }
        break;

        // Show view of yaw angles (for mag calibration/analysis)
    case Key_F6:
        if (down)
        {
            if (SceneMode != Scene_YawView)
            {
                SceneMode = Scene_YawView;  
                SetAdjustMessage("Magnetometer Yaw Angle Marks");
            }
            else
            {
                SceneMode = Scene_World;               
                SetAdjustMessage("Magnetometer Marks Off");
            }
        }
        break;

    case Key_C:
        if (down)
        {
            // Toggle chromatic aberration correction on/off.
            RenderDevice::PostProcessShader shader = pRender->GetPostProcessShader();

            if (shader == RenderDevice::PostProcessShader_Distortion)
            {
                pRender->SetPostProcessShader(RenderDevice::PostProcessShader_DistortionAndChromAb);                
                SetAdjustMessage("Chromatic Aberration Correction On");
            }
            else if (shader == RenderDevice::PostProcessShader_DistortionAndChromAb)
            {
                pRender->SetPostProcessShader(RenderDevice::PostProcessShader_Distortion);                
                SetAdjustMessage("Chromatic Aberration Correction Off");
            }
            else
                OVR_ASSERT(false);
        }
        break;

    case Key_P:
        if (down)
        {
            // Toggle motion prediction.
            if (SFusion.IsPredictionEnabled())
            {
                SFusion.SetPredictionEnabled(false);
                SetAdjustMessage("Motion Prediction Off");
            }
            else
            {
                SFusion.SetPredictionEnabled(true);
                SetAdjustMessage("Motion Prediction On");
            }      
        }
        break;
     default:
        break;
    }
}

void OculusWorldDemoApp::OnIdle()
{

    double curtime = pPlatform->GetAppTime();
    float  dt      = float(curtime - LastUpdate);
    LastUpdate     = curtime;

    // Update gamepad.
    GamepadState gamepadState;
    if (GetPlatformCore()->GetGamepadManager()->GetGamepadState(0, &gamepadState))
    {
        GamepadStateChanged(gamepadState);
    }


    if (LoadingState == LoadingState_DoLoad)
    {
        PopulateScene(MainFilePath.ToCStr());
        LoadingState = LoadingState_Finished;
        return;
    }
    
    // Check if any new devices were connected.
    {
        bool queueIsEmpty = false;
        while (!queueIsEmpty)
        {
            DeviceStatusNotificationDesc desc;

            {
                Lock::Locker lock(pManager->GetHandlerLock());
                if (DeviceStatusNotificationsQueue.GetSize() == 0)
                    break;
                desc = DeviceStatusNotificationsQueue.Front();
             
                // We can't call Clear under the lock since this may introduce a dead lock:
                // this thread is locked by HandlerLock and the Clear might cause 
                // call of Device->Release, which will use Manager->DeviceLock. The bkg
                // thread is most likely locked by opposite way: 
                // Manager->DeviceLock ==> HandlerLock, therefore - a dead lock.
                // So, just grab the first element, save a copy of it and remove
                // the element (Device->Release won't be called since we made a copy).
                
                DeviceStatusNotificationsQueue.RemoveAt(0);
                queueIsEmpty = (DeviceStatusNotificationsQueue.GetSize() == 0);
            }

            bool wasAlreadyCreated = desc.Handle.IsCreated();

            if (desc.Action == Message_DeviceAdded)
            {
                switch(desc.Handle.GetType())
                {
                case Device_Sensor:
                    if (desc.Handle.IsAvailable() && !desc.Handle.IsCreated())
                    {
                        if (!pSensor)
                        {
                            pSensor = *desc.Handle.CreateDeviceTyped<SensorDevice>();
							if (pSensor)
							{
								SFusion.AttachToSensor(pSensor);

								SetAdjustMessage("---------------------------\n"
												 "SENSOR connected\n"
												 "---------------------------");
							}
							else
							{
								SetAdjustMessage("----------------------------\n"
												 "SENSOR connect failed\n"
												 "Unplug and reconnect it.\n"
												 "----------------------------");
							}
                        }
                        else if (!wasAlreadyCreated)
                        {
                            LogText("A new SENSOR has been detected, but it is not currently used.");
                        }
                    }
                    break;
                case Device_LatencyTester:
                    if (desc.Handle.IsAvailable() && !desc.Handle.IsCreated())
                    {
                        if (!pLatencyTester)
                        {
                            pLatencyTester = *desc.Handle.CreateDeviceTyped<LatencyTestDevice>();
                            LatencyUtil.SetDevice(pLatencyTester);
                            if (!wasAlreadyCreated)
                                SetAdjustMessage("----------------------------------------\n"
                                                 "LATENCY TESTER connected\n"
                                                 "----------------------------------------");
                        }
                    }
                    break;
                case Device_HMD:
                    {
                        OVR::HMDInfo info;
                        desc.Handle.GetDeviceInfo(&info);
                        // if strlen(info.DisplayDeviceName) == 0 then
                        // this HMD is 'fake' (created using sensor).
                        if (strlen(info.DisplayDeviceName) > 0 && (!pHMD || !info.IsSameDisplay(TheHMDInfo)))
                        {
                            SetAdjustMessage("------------------------\n"
                                             "HMD connected\n"
                                             "------------------------");
                            if (!pHMD || !desc.Handle.IsDevice(pHMD))
                                pHMD = *desc.Handle.CreateDeviceTyped<HMDDevice>();
                            // update stereo config with new HMDInfo
                            if (pHMD && pHMD->GetDeviceInfo(&TheHMDInfo))
                            {
                                //RenderParams.MonitorName = hmd.DisplayDeviceName;
                                SConfig.SetHMDInfo(TheHMDInfo);
                            }
                            LogText("HMD device added.\n");
                        }
                        break;
                    }
                default:;
                }
            }
            else if (desc.Action == Message_DeviceRemoved)
            {
                if (desc.Handle.IsDevice(pSensor))
                {
                    LogText("Sensor reported device removed.\n");
                    SFusion.AttachToSensor(NULL);
                    pSensor.Clear();
                    SetAdjustMessage("-------------------------------\n"
                                     "SENSOR disconnected.\n"
                                     "-------------------------------");
                }
                else if (desc.Handle.IsDevice(pLatencyTester))
                {
                    LogText("Latency Tester reported device removed.\n");
                    LatencyUtil.SetDevice(NULL);
                    pLatencyTester.Clear();
                    SetAdjustMessage("---------------------------------------------\n"
                                     "LATENCY SENSOR disconnected.\n"
                                     "---------------------------------------------");
                }
                else if (desc.Handle.IsDevice(pHMD))
                {
                    if (pHMD && !pHMD->IsDisconnected())
                    {
                        SetAdjustMessage("---------------------------\n"
                                         "HMD disconnected\n"
                                         "---------------------------");
                        // Disconnect HMD. pSensor is used to restore 'fake' HMD device
                        // (can be NULL).
                        pHMD = pHMD->Disconnect(pSensor);

                        // This will initialize TheHMDInfo with information about configured IPD,
                        // screen size and other variables needed for correct projection.
                        // We pass HMD DisplayDeviceName into the renderer to select the
                        // correct monitor in full-screen mode.
                        if (pHMD && pHMD->GetDeviceInfo(&TheHMDInfo))
                        {
                            //RenderParams.MonitorName = hmd.DisplayDeviceName;
                            SConfig.SetHMDInfo(TheHMDInfo);
                        }
                        LogText("HMD device removed.\n");
                    }
                }
            }
            else 
                OVR_ASSERT(0); // unexpected action
        }
    }

    // If one of Stereo setting adjustment keys is pressed, adjust related state.
    if (pAdjustFunc)
    {
        (this->*pAdjustFunc)(dt * AdjustDirection * (ShiftDown ? 5.0f : 1.0f));
    }

    // Process latency tester results.
    const char* results = LatencyUtil.GetResultsString();
    if (results != NULL)
    {
        LogText("LATENCY TESTER: %s\n", results); 
    }

    // >>> THIS MUST BE PLACED AS CLOSE AS POSSIBLE TO WHERE THE HMD ORIENTATION IS READ <<<
    LatencyUtil.ProcessInputs();

    // Handle Sensor motion.
    // We extract Yaw, Pitch, Roll instead of directly using the orientation
    // to allow "additional" yaw manipulation with mouse/controller.
    if(pSensor)
    {
        Quatf    hmdOrient = SFusion.GetPredictedOrientation();

        float    yaw = 0.0f;
        hmdOrient.GetEulerAngles<Axis_Y, Axis_X, Axis_Z>(&yaw, &ThePlayer.EyePitch, &ThePlayer.EyeRoll);

        ThePlayer.EyeYaw += (yaw - ThePlayer.LastSensorYaw);
        ThePlayer.LastSensorYaw = yaw;

        // NOTE: We can get a matrix from orientation as follows:
        // Matrix4f hmdMat(hmdOrient);

        // Test logic - assign quaternion result directly to view:
        // Quatf hmdOrient = SFusion.GetOrientation();
        // View = Matrix4f(hmdOrient.Inverted()) * Matrix4f::Translation(-EyePos);
    }


    if(curtime >= NextFPSUpdate)
    {
        NextFPSUpdate = curtime + 1.0;
        FPS = FrameCounter;
        FrameCounter = 0;
    }
    FrameCounter++;

    if(FPS < 40)
    {
        ConsecutiveLowFPSFrames++;
    }
    else
    {
        ConsecutiveLowFPSFrames = 0;
    }

    if(ConsecutiveLowFPSFrames > 200)
    {
        DropLOD();
        ConsecutiveLowFPSFrames = 0;
    }

    ThePlayer.EyeYaw -= ThePlayer.GamepadRotate.x * dt;
    ThePlayer.HandleCollision(dt, &CollisionModels, &GroundCollisionModels, ShiftDown);

    if(!pSensor)
    {
        ThePlayer.EyePitch -= ThePlayer.GamepadRotate.y * dt;

        const float maxPitch = ((3.1415f / 2) * 0.98f);
        if(ThePlayer.EyePitch > maxPitch)
        {
            ThePlayer.EyePitch = maxPitch;
        }
        if(ThePlayer.EyePitch < -maxPitch)
        {
            ThePlayer.EyePitch = -maxPitch;
        }
    }

    // Rotate and position View Camera, using YawPitchRoll in BodyFrame coordinates.
    //
    Matrix4f rollPitchYaw = Matrix4f::RotationY(ThePlayer.EyeYaw) * Matrix4f::RotationX(ThePlayer.EyePitch) *
                            Matrix4f::RotationZ(ThePlayer.EyeRoll);
    Vector3f up      = rollPitchYaw.Transform(UpVector);
    Vector3f forward = rollPitchYaw.Transform(ForwardVector);


    // Minimal head modeling; should be moved as an option to SensorFusion.
    float headBaseToEyeHeight     = 0.15f;  // Vertical height of eye from base of head
    float headBaseToEyeProtrusion = 0.09f;  // Distance forward of eye from base of head

    Vector3f eyeCenterInHeadFrame(0.0f, headBaseToEyeHeight, -headBaseToEyeProtrusion);
    Vector3f shiftedEyePos = ThePlayer.EyePos + rollPitchYaw.Transform(eyeCenterInHeadFrame);
    shiftedEyePos.y -= eyeCenterInHeadFrame.y; // Bring the head back down to original height
    View = Matrix4f::LookAtRH(shiftedEyePos, shiftedEyePos + forward, up);

    //  Transformation without head modeling.
    // View = Matrix4f::LookAtRH(EyePos, EyePos + forward, up);

    // This is an alternative to LookAtRH:
    // Here we transpose the rotation matrix to get its inverse.
    //  View = (Matrix4f::RotationY(EyeYaw) * Matrix4f::RotationX(EyePitch) *
    //                                        Matrix4f::RotationZ(EyeRoll)).Transposed() *
    //         Matrix4f::Translation(-EyePos);


    switch(SConfig.GetStereoMode())
    {
    case Stereo_None:
        Render(SConfig.GetEyeRenderParams(StereoEye_Center));
        break;

    case Stereo_LeftRight_Multipass:
        //case Stereo_LeftDouble_Multipass:
        Render(SConfig.GetEyeRenderParams(StereoEye_Left));
        Render(SConfig.GetEyeRenderParams(StereoEye_Right));
        break;

    }

    pRender->Present();
    // Force GPU to flush the scene, resulting in the lowest possible latency.
    pRender->ForceFlushGPU();
}


static const char* HelpText = 
    "F1         \t100 NoStereo\n"
    "F2         \t100 Stereo                     \t420 Z    \t520 Drift Correction\n"
    "F3         \t100 StereoHMD                  \t420 F6   \t520 Yaw Drift Info\n" 
    "F4         \t100 MSAA                       \t420 R    \t520 Reset SensorFusion\n"
    "F9         \t100 FullScreen                 \t420\n"
    "F11        \t100 Fast FullScreen                   \t500 - +       \t660 Adj EyeHeight\n"                                           
    "C          \t100 Chromatic Ab                      \t500 [ ]       \t660 Adj FOV\n"
    "P          \t100 Motion Pred                       \t500 Shift     \t660 Adj Faster\n"
    "N/M        \t180 Adj Motion Pred\n"
    "( / )      \t180 Adj EyeDistance"
    ;


enum DrawTextCenterType
{
    DrawText_NoCenter= 0,
    DrawText_VCenter = 0x1,
    DrawText_HCenter = 0x2,
    DrawText_Center  = DrawText_VCenter | DrawText_HCenter
};

static void DrawTextBox(RenderDevice* prender, float x, float y,
                        float textSize, const char* text,
                        DrawTextCenterType centerType = DrawText_NoCenter)
{
    float ssize[2] = {0.0f, 0.0f};

    prender->MeasureText(&DejaVu, text, textSize, ssize);

    // Treat 0 a VCenter.
    if (centerType & DrawText_HCenter)
    {
        x = -ssize[0]/2;
    }
    if (centerType & DrawText_VCenter)
    {
        y = -ssize[1]/2;
    }

    prender->FillRect(x-0.02f, y-0.02f, x+ssize[0]+0.02f, y+ssize[1]+0.02f, Color(40,40,100,210));
    prender->RenderText(&DejaVu, text, x, y, textSize, Color(255,255,0,210));
}

void OculusWorldDemoApp::Render(const StereoEyeParams& stereo)
{
    pRender->BeginScene(PostProcess);

    // *** 3D - Configures Viewport/Projection and Render
    pRender->ApplyStereoParams(stereo);    
    pRender->Clear();

    pRender->SetDepthMode(true, true);
    if (SceneMode != Scene_Grid)
    {
        MainScene.Render(pRender, stereo.ViewAdjust * View);
    }

    if (SceneMode == Scene_YawView)
    {
        Matrix4f trackerOnlyOrient = Matrix4f::RotationY(ThePlayer.LastSensorYaw) 
                                   * Matrix4f::RotationX(ThePlayer.EyePitch)
                                   * Matrix4f::RotationZ(ThePlayer.EyeRoll);
        YawLinesScene.Render(pRender, stereo.ViewAdjust * trackerOnlyOrient.Inverted());
        //YawMarkRedScene.Render(pRender, stereo.ViewAdjust);
    }

    // *** 2D Text & Grid - Configure Orthographic rendering.

    // Render UI in 2D orthographic coordinate system that maps [-1,1] range
    // to a readable FOV area centered at your eye and properly adjusted.
    pRender->ApplyStereoParams2D(stereo);    
    pRender->SetDepthMode(false, false);

    float unitPixel = SConfig.Get2DUnitPixel();
    float textHeight= unitPixel * 22; 

    if ((SceneMode == Scene_Grid)||(SceneMode == Scene_Both))
    {   // Draw grid two pixels thick.
        GridScene.Render(pRender, Matrix4f());
        GridScene.Render(pRender, Matrix4f::Translation(unitPixel,unitPixel,0));
    }

    // Display Loading screen-shot in frame 0.
    if (LoadingState != LoadingState_Finished)
    {
        LoadingScene.Render(pRender, Matrix4f());
        String loadMessage = String("Loading ") + MainFilePath;
        DrawTextBox(pRender, 0.0f, 0.0f, textHeight, loadMessage.ToCStr(), DrawText_HCenter);
        LoadingState = LoadingState_DoLoad;
    }

    if(!AdjustMessage.IsEmpty() && AdjustMessageTimeout > pPlatform->GetAppTime())
    {
        DrawTextBox(pRender,0.0f,0.4f, textHeight, AdjustMessage.ToCStr(), DrawText_HCenter);
    }

    switch(TextScreen)
    {
    case Text_Orientation:
    {
        char buf[256], gpustat[256];
        OVR_sprintf(buf, sizeof(buf),
                    " Yaw:%4.0f  Pitch:%4.0f  Roll:%4.0f \n"
                    " FPS: %d  Frame: %d \n Pos: %3.2f, %3.2f, %3.2f \n"
                    " EyeHeight: %3.2f",
                    RadToDegree(ThePlayer.EyeYaw), RadToDegree(ThePlayer.EyePitch), RadToDegree(ThePlayer.EyeRoll),
                    FPS, FrameCounter, ThePlayer.EyePos.x, ThePlayer.EyePos.y, ThePlayer.EyePos.z, ThePlayer.UserEyeHeight);
        size_t texMemInMB = pRender->GetTotalTextureMemoryUsage() / 1058576;
        if (texMemInMB)
        {
            OVR_sprintf(gpustat, sizeof(gpustat), "\n GPU Tex: %u MB", texMemInMB);
            OVR_strcat(buf, sizeof(buf), gpustat);
        }
        
        DrawTextBox(pRender, 0.0f, -0.15f, textHeight, buf, DrawText_HCenter);
    }
    break;

    case Text_Config:
    {
        char   textBuff[2048];
         
        OVR_sprintf(textBuff, sizeof(textBuff),
                    "Fov\t300 %9.4f\n"
                    "EyeDistance\t300 %9.4f\n"
                    "DistortionK0\t300 %9.4f\n"
                    "DistortionK1\t300 %9.4f\n"
                    "DistortionK2\t300 %9.4f\n"
                    "DistortionK3\t300 %9.4f\n"
                    "TexScale\t300 %9.4f",
                    SConfig.GetYFOVDegrees(),
                        SConfig.GetIPD(),
                    SConfig.GetDistortionK(0),
                    SConfig.GetDistortionK(1),
                    SConfig.GetDistortionK(2),
                    SConfig.GetDistortionK(3),
                    SConfig.GetDistortionScale());

            DrawTextBox(pRender, 0.0f, 0.0f, textHeight, textBuff, DrawText_Center);
    }
    break;

    case Text_Help:
        DrawTextBox(pRender, 0.0f, -0.1f, textHeight, HelpText, DrawText_Center);
            
    default:
        break;
    }


    // Display colored quad if we're doing a latency test.
    Color colorToDisplay;
    if (LatencyUtil.DisplayScreenColor(colorToDisplay))
    {
        pRender->FillRect(-0.4f, -0.4f, 0.4f, 0.4f, colorToDisplay);
    }

    pRender->FinishScene();
}


// Sets temporarily displayed message for adjustments
void OculusWorldDemoApp::SetAdjustMessage(const char* format, ...)
{
    Lock::Locker lock(pManager->GetHandlerLock());
    char textBuff[2048];
    va_list argList;
    va_start(argList, format);
    OVR_vsprintf(textBuff, sizeof(textBuff), format, argList);
    va_end(argList);

    // Message will time out in 4 seconds.
    AdjustMessage = textBuff;
    AdjustMessageTimeout = pPlatform->GetAppTime() + 4.0f;
}

void OculusWorldDemoApp::SetAdjustMessageTimeout(float timeout)
{
    AdjustMessageTimeout = pPlatform->GetAppTime() + timeout;
}

// ***** View Control Adjustments

void OculusWorldDemoApp::AdjustFov(float dt)
{
    float esd = SConfig.GetEyeToScreenDistance() + 0.01f * dt;
    SConfig.SetEyeToScreenDistance(esd);
    SetAdjustMessage("ESD:%6.3f  FOV: %6.3f", esd, SConfig.GetYFOVDegrees());
}

void OculusWorldDemoApp::AdjustAspect(float dt)
{
    float rawAspect = SConfig.GetAspect() / SConfig.GetAspectMultiplier();
    float newAspect = SConfig.GetAspect() + 0.01f * dt;
    SConfig.SetAspectMultiplier(newAspect / rawAspect);
    SetAdjustMessage("Aspect: %6.3f", newAspect);
}

void OculusWorldDemoApp::AdjustDistortion(float dt, int kIndex, const char* label)
{
    SConfig.SetDistortionK(kIndex, SConfig.GetDistortionK(kIndex) + 0.03f * dt);
    SetAdjustMessage("%s: %6.4f", label, SConfig.GetDistortionK(kIndex));
}

void OculusWorldDemoApp::AdjustIPD(float dt)
{
    SConfig.SetIPD(SConfig.GetIPD() + 0.025f * dt);
    SetAdjustMessage("EyeDistance: %6.4f", SConfig.GetIPD());
}

void OculusWorldDemoApp::AdjustEyeHeight(float dt)
{
    float dist = 0.5f * dt;

    ThePlayer.UserEyeHeight += dist;
    ThePlayer.EyePos.y += dist;

    SetAdjustMessage("UserEyeHeight: %4.2f", ThePlayer.UserEyeHeight);
}

void OculusWorldDemoApp::AdjustMotionPrediction(float dt)
{
    float motionPred = SFusion.GetPredictionDelta() + 0.01f * dt;

    if (motionPred < 0.0f)
    {
        motionPred = 0.0f;
    }
    
    SFusion.SetPrediction(motionPred);

    SetAdjustMessage("MotionPrediction: %6.3fs", motionPred);
}

void OculusWorldDemoApp::AdjustDistortion(float val, int kIndex)
{
    SConfig.SetDistortionK(kIndex, val);
    SetAdjustMessage("K%d: %6.4f", kIndex, SConfig.GetDistortionK(kIndex));
}

void OculusWorldDemoApp::AdjustEsd(float val)
{
    SConfig.SetEyeToScreenDistance(val);
	float esd = SConfig.GetEyeToScreenDistance();
    SetAdjustMessage("ESD:%6.3f  FOV: %6.3f", esd, SConfig.GetYFOVDegrees());
}

// Loads the scene data
void OculusWorldDemoApp::PopulateScene(const char *fileName)
{    
    XmlHandler xmlHandler;     
    if(!xmlHandler.ReadFile(fileName, pRender, &MainScene, &CollisionModels, &GroundCollisionModels))
    {
        SetAdjustMessage("---------------------------------\nFILE LOAD FAILED\n---------------------------------");
        SetAdjustMessageTimeout(10.0f);
    }    

    MainScene.SetAmbient(Vector4f(1.0f, 1.0f, 1.0f, 1.0f));
    
    // Distortion debug grid (brought up by 'G' key).
    Ptr<Model> gridModel = *Model::CreateGrid(Vector3f(0,0,0), Vector3f(1.0f/10, 0,0), Vector3f(0,1.0f/10,0),
                                              10, 10, 5, 
                                              Color(0, 255, 0, 255), Color(255, 50, 50, 255) );
    GridScene.World.Add(gridModel);

    // Yaw angle marker and lines (brought up by ';' key).
    float shifty = -0.5f;
    Ptr<Model> yawMarkGreenModel = *Model::CreateBox(Color(0, 255, 0, 255), Vector3f(0.0f, shifty, -2.0f), Vector3f(0.05f, 0.05f, 0.05f));
    YawMarkGreenScene.World.Add(yawMarkGreenModel);
    Ptr<Model> yawMarkRedModel = *Model::CreateBox(Color(255, 0, 0, 255), Vector3f(0.0f, shifty, -2.0f), Vector3f(0.05f, 0.05f, 0.05f));
    YawMarkRedScene.World.Add(yawMarkRedModel);

    Ptr<Model> yawLinesModel = *new Model();
    Color c = Color(255, 200, 200, 255);
    float r = 1.5f;
    yawLinesModel->AddTriangle(yawLinesModel->AddVertex(Vector3f(-0.1f, 0, -r), c), 
                               yawLinesModel->AddVertex(Vector3f(0, 0, -r-0.2f), c),
                               yawLinesModel->AddVertex(Vector3f(0.1f, 0, -r), c));
    yawLinesModel->AddTriangle(yawLinesModel->AddVertex(Vector3f(-r-0.1f, 0, -r), c), 
                               yawLinesModel->AddVertex(Vector3f(-r, 0, -r-0.2f), c),
                               yawLinesModel->AddVertex(Vector3f(-r+0.1f, 0, -r), c));
    yawLinesModel->AddTriangle(yawLinesModel->AddVertex(Vector3f(r-0.1f, 0, -r), c), 
                               yawLinesModel->AddVertex(Vector3f(r, 0, -r-0.2f), c),
                               yawLinesModel->AddVertex(Vector3f(r+0.1f, 0, -r), c));
    yawLinesModel->SetPosition(Vector3f(0.0f,-1.2f,0.0f));
    YawLinesScene.World.Add(yawLinesModel);
}


void OculusWorldDemoApp::PopulatePreloadScene()
{
    // Load-screen screen shot image
    String fileName = MainFilePath;
    fileName.StripExtension();

    Ptr<File>    imageFile = *new SysFile(fileName + "_LoadScreen.tga");
    Ptr<Texture> imageTex;
    if (imageFile->IsValid())
        imageTex = *LoadTextureTga(pRender, imageFile);

    // Image is rendered as a single quad.
    if (imageTex)
    {
        imageTex->SetSampleMode(Sample_Anisotropic|Sample_Repeat);
        Ptr<Model> m = *new Model(Prim_Triangles);        
        m->AddVertex(-0.5f,  0.5f,  0.0f, Color(255,255,255,255), 0.0f, 0.0f);
        m->AddVertex( 0.5f,  0.5f,  0.0f, Color(255,255,255,255), 1.0f, 0.0f);
        m->AddVertex( 0.5f, -0.5f,  0.0f, Color(255,255,255,255), 1.0f, 1.0f);
        m->AddVertex(-0.5f, -0.5f,  0.0f, Color(255,255,255,255), 0.0f, 1.0f);
        m->AddTriangle(2,1,0);
        m->AddTriangle(0,3,2);

        Ptr<ShaderFill> fill = *new ShaderFill(*pRender->CreateShaderSet());
        fill->GetShaders()->SetShader(pRender->LoadBuiltinShader(Shader_Vertex, VShader_MVP)); 
        fill->GetShaders()->SetShader(pRender->LoadBuiltinShader(Shader_Fragment, FShader_Texture)); 
        fill->SetTexture(0, imageTex);
        m->Fill = fill;

        LoadingScene.World.Add(m);
    }
}

void OculusWorldDemoApp::ClearScene()
{
    MainScene.Clear();
    GridScene.Clear();
    YawMarkGreenScene.Clear();
    YawMarkRedScene.Clear();
    YawLinesScene.Clear();
}

void OculusWorldDemoApp::PopulateLODFileNames()
{
    //OVR::String mainFilePath = MainFilePath;
    LODFilePaths.PushBack(MainFilePath);
    int   LODIndex = 1;
    SPInt pos = strcspn(MainFilePath.ToCStr(), ".");
    SPInt len = strlen(MainFilePath.ToCStr());
    SPInt diff = len - pos;

    if (diff == 0)
        return;    

    while(true)
    {
        char pathWithoutExt[250];
        char buffer[250];
        for(SPInt i = 0; i < pos; ++i)
        {
            pathWithoutExt[i] = MainFilePath[(int)i];
        }
        pathWithoutExt[pos] = '\0';
        OVR_sprintf(buffer, sizeof(buffer), "%s%i.xml", pathWithoutExt, LODIndex);
        FILE* fp = 0;
#if defined(_MSC_VER) && (_MSC_VER >= 1400 )
        errno_t err = fopen_s(&fp, buffer, "rb");
        if(!fp || err)
        {
#else
        fp = fopen(buffer, "rb");
        if(!fp)
        {
#endif
            break;
        }
        fclose(fp);
        OVR::String result = buffer;
        LODFilePaths.PushBack(result);
        LODIndex++;
    }
}

void OculusWorldDemoApp::DropLOD()
{
    if(CurrentLODFileIndex < (int)(LODFilePaths.GetSize() - 1))
    {
        ClearScene();
        CurrentLODFileIndex++;
        PopulateScene(LODFilePaths[CurrentLODFileIndex].ToCStr());
    }
}

void OculusWorldDemoApp::RaiseLOD()
{
    if(CurrentLODFileIndex > 0)
    {
        ClearScene();
        CurrentLODFileIndex--;
        PopulateScene(LODFilePaths[CurrentLODFileIndex].ToCStr());
    }
}

//-----------------------------------------------------------------------------
void OculusWorldDemoApp::CycleDisplay()
{
    int screenCount = pPlatform->GetDisplayCount();

    // If Windowed, switch to the HMD screen first in Full-Screen Mode.
    // If already Full-Screen, cycle to next screen until we reach FirstScreenInCycle.

    if (pRender->IsFullscreen())
    {
        // Right now, we always need to restore window before going to next screen.
        pPlatform->SetFullscreen(RenderParams, Display_Window);

        Screen++;
        if (Screen == screenCount)
            Screen = 0;

        RenderParams.Display = pPlatform->GetDisplay(Screen);

        if (Screen != FirstScreenInCycle)
        {
            pRender->SetParams(RenderParams);
            pPlatform->SetFullscreen(RenderParams, Display_Fullscreen);
        }
    }
    else
    {
        // Try to find HMD Screen, making it the first screen in full-screen Cycle.        
        FirstScreenInCycle = 0;

        if (pHMD)
        {
            DisplayId HMD (SConfig.GetHMDInfo().DisplayDeviceName, SConfig.GetHMDInfo().DisplayId);
            for (int i = 0; i< screenCount; i++)
            {   
                if (pPlatform->GetDisplay(i) == HMD)
                {
                    FirstScreenInCycle = i;
                    break;
                }
            }            
        }

        // Switch full-screen on the HMD.
        Screen = FirstScreenInCycle;
        RenderParams.Display = pPlatform->GetDisplay(Screen);
        pRender->SetParams(RenderParams);
        pPlatform->SetFullscreen(RenderParams, Display_Fullscreen);
    }
}

void OculusWorldDemoApp::GamepadStateChanged(const GamepadState& pad)
{
    ThePlayer.GamepadMove   = Vector3f(pad.LX * pad.LX * (pad.LX > 0 ? 1 : -1),
                             0,
                             pad.LY * pad.LY * (pad.LY > 0 ? -1 : 1));
    ThePlayer.GamepadRotate = Vector3f(2 * pad.RX, -2 * pad.RY, 0);
}


//-------------------------------------------------------------------------------------

OVR_PLATFORM_APP(OculusWorldDemoApp);