#ifdef BT_ENABLE_VR
//========= Copyright Valve Corporation ============//

#include "../OpenGLWindow/SimpleOpenGL3App.h"
#include "../OpenGLWindow/OpenGLInclude.h"
#include "Bullet3Common/b3Quaternion.h"
#include "Bullet3Common/b3Transform.h"

#include "../ExampleBrowser/OpenGLGuiHelper.h"
#include "../CommonInterfaces/CommonExampleInterface.h"
#include "../CommonInterfaces/CommonGUIHelperInterface.h"
#include "BulletCollision/CollisionDispatch/btCollisionObject.h"
#include "BulletCollision/CollisionShapes/btCollisionShape.h"
#include "BulletDynamics/Dynamics/btDiscreteDynamicsWorld.h"

#include "LinearMath/btIDebugDraw.h"
int gSharedMemoryKey = -1;
int  gDebugDrawFlags = 0;

//how can you try typing on a keyboard, without seeing it?
//it is pretty funny, to see the desktop in VR!


#include <stdio.h>
#include <string>
#include <cstdlib>

#include <openvr.h>

#include "lodepng.h"
#include "Matrices.h"
#include "pathtools.h"

CommonExampleInterface*    sExample;

int sPrevPacketNum=0;
OpenGLGuiHelper* sGuiPtr = 0;


static vr::VRControllerState_t sPrevStates[vr::k_unMaxTrackedDeviceCount] = { 0 };


#if defined(POSIX)
#include "unistd.h"
#endif
#ifdef _WIN32
#include <Windows.h>
#endif

void ThreadSleep( unsigned long nMilliseconds )
{
#if defined(_WIN32)
	::Sleep( nMilliseconds );
#elif defined(POSIX)
	usleep( nMilliseconds * 1000 );
#endif
}


class CGLRenderModel
{
public:
	CGLRenderModel( const std::string & sRenderModelName );
	~CGLRenderModel();

	bool BInit( const vr::RenderModel_t & vrModel, const vr::RenderModel_TextureMap_t & vrDiffuseTexture );
	void Cleanup();
	void Draw();
	const std::string & GetName() const { return m_sModelName; }

private:
	GLuint m_glVertBuffer;
	GLuint m_glIndexBuffer;
	GLuint m_glVertArray;
	GLuint m_glTexture;
	GLsizei m_unVertexCount;
	std::string m_sModelName;
};

static bool g_bPrintf = true;

//-----------------------------------------------------------------------------
// Purpose:
//------------------------------------------------------------------------------
class CMainApplication
{
public:
	CMainApplication( int argc, char *argv[] );
	virtual ~CMainApplication();

	bool BInit();
	bool BInitGL();
	bool BInitCompositor();
	void getControllerTransform(int unDevice, b3Transform& tr);
	void SetupRenderModels();

	void Shutdown();

	void RunMainLoop();
	bool HandleInput();
	void ProcessVREvent( const vr::VREvent_t & event );
	void RenderFrame();

	bool SetupTexturemaps();

	void SetupScene();
	void AddCubeToScene( Matrix4 mat, std::vector<float> &vertdata );
	void AddCubeVertex( float fl0, float fl1, float fl2, float fl3, float fl4, std::vector<float> &vertdata );

	void DrawControllers();

	bool SetupStereoRenderTargets();
	void SetupDistortion();
	void SetupCameras();

	void RenderStereoTargets();
	void RenderDistortion();
	void RenderScene( vr::Hmd_Eye nEye );

	Matrix4 GetHMDMatrixProjectionEye( vr::Hmd_Eye nEye );
	Matrix4 GetHMDMatrixPoseEye( vr::Hmd_Eye nEye );
	Matrix4 GetCurrentViewProjectionMatrix( vr::Hmd_Eye nEye );
	void UpdateHMDMatrixPose();

	Matrix4 ConvertSteamVRMatrixToMatrix4( const vr::HmdMatrix34_t &matPose );

	GLuint CompileGLShader( const char *pchShaderName, const char *pchVertexShader, const char *pchFragmentShader );
	bool CreateAllShaders();

	void SetupRenderModelForTrackedDevice( vr::TrackedDeviceIndex_t unTrackedDeviceIndex );
	CGLRenderModel *FindOrLoadRenderModel( const char *pchRenderModelName );

private: 
	bool m_bDebugOpenGL;
	bool m_bVerbose;
	bool m_bPerf;
	bool m_bVblank;
	bool m_bGlFinishHack;

	vr::IVRSystem *m_pHMD;
	vr::IVRRenderModels *m_pRenderModels;
	std::string m_strDriver;
	std::string m_strDisplay;
	vr::TrackedDevicePose_t m_rTrackedDevicePose[ vr::k_unMaxTrackedDeviceCount ];
	Matrix4 m_rmat4DevicePose[ vr::k_unMaxTrackedDeviceCount ];
	bool m_rbShowTrackedDevice[ vr::k_unMaxTrackedDeviceCount ];

private: 
	SimpleOpenGL3App* m_app;
	uint32_t m_nWindowWidth;
	uint32_t m_nWindowHeight;
	bool m_hasContext;

private: // OpenGL bookkeeping
	int m_iTrackedControllerCount;
	int m_iTrackedControllerCount_Last;
	int m_iValidPoseCount;
	int m_iValidPoseCount_Last;
	bool m_bShowCubes;

	std::string m_strPoseClasses;                            // what classes we saw poses for this frame
	char m_rDevClassChar[ vr::k_unMaxTrackedDeviceCount ];   // for each device, a character representing its class

	int m_iSceneVolumeWidth;
	int m_iSceneVolumeHeight;
	int m_iSceneVolumeDepth;
	float m_fScaleSpacing;
	float m_fScale;
	
	int m_iSceneVolumeInit;                                  // if you want something other than the default 20x20x20
	
	float m_fNearClip;
	float m_fFarClip;

	GLuint m_iTexture;

	unsigned int m_uiVertcount;

	GLuint m_glSceneVertBuffer;
	GLuint m_unSceneVAO;
	GLuint m_unLensVAO;
	GLuint m_glIDVertBuffer;
	GLuint m_glIDIndexBuffer;
	unsigned int m_uiIndexSize;

	GLuint m_glControllerVertBuffer;
	GLuint m_unControllerVAO;
	unsigned int m_uiControllerVertcount;

	Matrix4 m_mat4HMDPose;
	Matrix4 m_mat4eyePosLeft;
	Matrix4 m_mat4eyePosRight;

	Matrix4 m_mat4ProjectionCenter;
	Matrix4 m_mat4ProjectionLeft;
	Matrix4 m_mat4ProjectionRight;

	struct VertexDataScene
	{
		Vector3 position;
		Vector2 texCoord;
	};

	struct VertexDataLens
	{
		Vector2 position;
		Vector2 texCoordRed;
		Vector2 texCoordGreen;
		Vector2 texCoordBlue;
	};

	GLuint m_unSceneProgramID;
	GLuint m_unLensProgramID;
	GLuint m_unControllerTransformProgramID;
	GLuint m_unRenderModelProgramID;

	GLint m_nSceneMatrixLocation;
	GLint m_nControllerMatrixLocation;
	GLint m_nRenderModelMatrixLocation;

	struct FramebufferDesc
	{
		GLuint m_nDepthBufferId;
		GLuint m_nRenderTextureId;
		GLuint m_nRenderFramebufferId;
		GLuint m_nResolveTextureId;
		GLuint m_nResolveFramebufferId;
	};
	FramebufferDesc leftEyeDesc;
	FramebufferDesc rightEyeDesc;

	bool CreateFrameBuffer( int nWidth, int nHeight, FramebufferDesc &framebufferDesc );
	
	uint32_t m_nRenderWidth;
	uint32_t m_nRenderHeight;

	std::vector< CGLRenderModel * > m_vecRenderModels;
	CGLRenderModel *m_rTrackedDeviceToRenderModel[ vr::k_unMaxTrackedDeviceCount ];
};


//-----------------------------------------------------------------------------
// Purpose: Constructor
//-----------------------------------------------------------------------------
CMainApplication::CMainApplication( int argc, char *argv[] )
	: m_app(NULL)
	, m_hasContext(false)
	, m_nWindowWidth( 1280 )
	, m_nWindowHeight( 720 )
	, m_unSceneProgramID( 0 )
	, m_unLensProgramID( 0 )
	, m_unControllerTransformProgramID( 0 )
	, m_unRenderModelProgramID( 0 )
	, m_pHMD( NULL )
	, m_pRenderModels( NULL )
	, m_bDebugOpenGL( false )
	, m_bVerbose( false )
	, m_bPerf( false )
	, m_bVblank( false )
	, m_bGlFinishHack( true )
	, m_glControllerVertBuffer( 0 )
	, m_unControllerVAO( 0 )
	, m_unLensVAO( 0 )
	, m_unSceneVAO( 0 )
	, m_nSceneMatrixLocation( -1 )
	, m_nControllerMatrixLocation( -1 )
	, m_nRenderModelMatrixLocation( -1 )
	, m_iTrackedControllerCount( 0 )
	, m_iTrackedControllerCount_Last( -1 )
	, m_iValidPoseCount( 0 )
	, m_iValidPoseCount_Last( -1 )
	, m_iSceneVolumeInit( 20 )
	, m_strPoseClasses("")
	, m_bShowCubes( false )
{

	for( int i = 1; i < argc; i++ )
	{
		if( !stricmp( argv[i], "-gldebug" ) )
		{
			m_bDebugOpenGL = true;
		}
		else if( !stricmp( argv[i], "-verbose" ) )
		{
			m_bVerbose = true;
		}
		else if( !stricmp( argv[i], "-novblank" ) )
		{
			m_bVblank = false;
		}
		else if( !stricmp( argv[i], "-noglfinishhack" ) )
		{
			m_bGlFinishHack = false;
		}
		else if( !stricmp( argv[i], "-noprintf" ) )
		{
			g_bPrintf = false;
		}
		else if ( !stricmp( argv[i], "-cubevolume" ) && ( argc > i + 1 ) && ( *argv[ i + 1 ] != '-' ) )
		{
			m_iSceneVolumeInit = atoi( argv[ i + 1 ] );
			i++;
		}
	}
	// other initialization tasks are done in BInit
	memset(m_rDevClassChar, 0, sizeof(m_rDevClassChar));
};


//-----------------------------------------------------------------------------
// Purpose: Destructor
//-----------------------------------------------------------------------------
CMainApplication::~CMainApplication()
{
	// work is done in Shutdown
	b3Printf( "Shutdown" );
}


//-----------------------------------------------------------------------------
// Purpose: Helper to get a string from a tracked device property and turn it
//			into a std::string
//-----------------------------------------------------------------------------
std::string GetTrackedDeviceString( vr::IVRSystem *pHmd, vr::TrackedDeviceIndex_t unDevice, vr::TrackedDeviceProperty prop, vr::TrackedPropertyError *peError = NULL )
{
	uint32_t unRequiredBufferLen = pHmd->GetStringTrackedDeviceProperty( unDevice, prop, NULL, 0, peError );
	if( unRequiredBufferLen == 0 )
		return "";

	char *pchBuffer = new char[ unRequiredBufferLen ];
	unRequiredBufferLen = pHmd->GetStringTrackedDeviceProperty( unDevice, prop, pchBuffer, unRequiredBufferLen, peError );
	std::string sResult = pchBuffer;
	delete [] pchBuffer;
	return sResult;
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
bool CMainApplication::BInit()
{
	
	// Loading the SteamVR Runtime
	vr::EVRInitError eError = vr::VRInitError_None;
	m_pHMD = vr::VR_Init( &eError, vr::VRApplication_Scene );

	if ( eError != vr::VRInitError_None )
	{
		m_pHMD = NULL;
		char buf[1024];
		sprintf_s( buf, sizeof( buf ), "Unable to init VR runtime: %s", vr::VR_GetVRInitErrorAsEnglishDescription( eError ) );
		b3Warning( "VR_Init Failed %s", buf);
		return false;
	}


	m_pRenderModels = (vr::IVRRenderModels *)vr::VR_GetGenericInterface( vr::IVRRenderModels_Version, &eError );
	if( !m_pRenderModels )
	{
		m_pHMD = NULL;
		vr::VR_Shutdown();

		char buf[1024];
		sprintf_s( buf, sizeof( buf ), "Unable to get render model interface: %s", vr::VR_GetVRInitErrorAsEnglishDescription( eError ) );
		b3Warning( "VR_Init Failed %s", buf);
		return false;
	}

//	int nWindowPosX = 700;
//	int nWindowPosY = 100;
	m_nWindowWidth = 1280;
	m_nWindowHeight = 720;

	/*
	
	//SDL_GL_SetAttribute( SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_COMPATIBILITY );
	SDL_GL_SetAttribute( SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE );
	SDL_GL_SetAttribute( SDL_GL_MULTISAMPLEBUFFERS, 0 );
	SDL_GL_SetAttribute( SDL_GL_MULTISAMPLESAMPLES, 0 );
	if( m_bDebugOpenGL )
		SDL_GL_SetAttribute( SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_DEBUG_FLAG );

	*/
	m_app = new SimpleOpenGL3App("SimpleOpenGL3App",m_nWindowWidth,m_nWindowHeight,true);

	
	sGuiPtr = new OpenGLGuiHelper(m_app,false);
	sGuiPtr->setVRMode(true);

	//sGuiPtr = new DummyGUIHelper;

    
	CommonExampleOptions options(sGuiPtr);

	sExample = StandaloneExampleCreateFunc(options);
	 sExample->initPhysics();
	sExample->resetCamera();

#if 0
	int cubeIndex = m_app->registerCubeShape(1,1,1);
    
    b3Quaternion orn(0,0,0,1);
    
	{
		b3Vector3 color=b3MakeVector3(0.3,0.3,0.6);
		b3Vector3 pos = b3MakeVector3(0,0,0);
		b3Vector3 scaling=b3MakeVector3 (1,.1,1);
		m_app->m_renderer->registerGraphicsInstance(cubeIndex,pos,orn,color,scaling);
	}
	{
		b3Vector3 color=b3MakeVector3(0.3,0.6,0.3);
		b3Vector3 pos = b3MakeVector3(0,0.3,0);
		b3Vector3 scaling=b3MakeVector3 (.1,.1,.1);
		m_app->m_renderer->registerGraphicsInstance(cubeIndex,pos,orn,color,scaling);
	}
#endif

	

	m_app->m_renderer->writeTransforms();



/*	if (m_pWindow == NULL)
	{
		printf( "%s - Window could not be created! SDL Error: %s\n", __FUNCTION__, SDL_GetError() );
		return false;
	}
	*/

	/*m_pContext = SDL_GL_CreateContext(m_pWindow);
	if (m_pContext == NULL)
	{
		printf( "%s - OpenGL context could not be created! SDL Error: %s\n", __FUNCTION__, SDL_GetError() );
		return false;
	}


	glewExperimental = GL_TRUE;
	GLenum nGlewError = glewInit();
	if (nGlewError != GLEW_OK)
	{
		printf( "%s - Error initializing GLEW! %s\n", __FUNCTION__, glewGetErrorString( nGlewError ) );
		return false;
	}
	glGetError(); // to clear the error caused deep in GLEW

	if ( SDL_GL_SetSwapInterval( m_bVblank ? 1 : 0 ) < 0 )
	{
		printf( "%s - Warning: Unable to set VSync! SDL Error: %s\n", __FUNCTION__, SDL_GetError() );
		return false;
	}

		*/
	m_strDriver = "No Driver";
	m_strDisplay = "No Display";

	m_strDriver = GetTrackedDeviceString( m_pHMD, vr::k_unTrackedDeviceIndex_Hmd, vr::Prop_TrackingSystemName_String );
	m_strDisplay = GetTrackedDeviceString( m_pHMD, vr::k_unTrackedDeviceIndex_Hmd, vr::Prop_SerialNumber_String );

	std::string strWindowTitle = "hellovr_bullet - " + m_strDriver + " " + m_strDisplay;
	m_app->m_window->setWindowTitle(strWindowTitle.c_str() );
	
	// cube array
 	m_iSceneVolumeWidth = m_iSceneVolumeInit;
 	m_iSceneVolumeHeight = m_iSceneVolumeInit;
 	m_iSceneVolumeDepth = m_iSceneVolumeInit;
 		
 	m_fScale = 0.3f;
 	m_fScaleSpacing = 4.0f;
 
 	m_fNearClip = 0.1f;
 	m_fFarClip = 3000.0f;
 
 	m_iTexture = 0;
 	m_uiVertcount = 0;
 
// 		m_MillisecondsTimer.start(1, this);
// 		m_SecondsTimer.start(1000, this);
	
	if (!BInitGL())
	{
		printf("%s - Unable to initialize OpenGL!\n", __FUNCTION__);
		return false;
	}

	if (!BInitCompositor())
	{
		printf("%s - Failed to initialize VR Compositor!\n", __FUNCTION__);
		return false;
	}

	return true;
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
/*void APIENTRY DebugCallback(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const char* message, const void* userParam)
{
	b3Printf( "GL Error: %s\n", message );
}
*/

static void APIENTRY DebugCallback (GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar* message, GLvoid* userParam)
{
	b3Printf( "GL Error: %s\n", message );
}

//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
bool CMainApplication::BInitGL()
{
	if( m_bDebugOpenGL )
	{
		const GLvoid *userParam=0;
		glDebugMessageCallback(DebugCallback,  userParam);
		glDebugMessageControl( GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, nullptr, GL_TRUE );
		glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
	}

	if( !CreateAllShaders() )
		return false;

	SetupTexturemaps();
	SetupScene();
	SetupCameras();
	SetupStereoRenderTargets();
	SetupDistortion();

	SetupRenderModels();

	return true;
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
bool CMainApplication::BInitCompositor()
{
	vr::EVRInitError peError = vr::VRInitError_None;

	if ( !vr::VRCompositor() )
	{
		printf( "Compositor initialization failed. See log file for details\n" );
		return false;
	}

	return true;
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void CMainApplication::Shutdown()
{
	if( m_pHMD )
	{
		vr::VR_Shutdown();
		m_pHMD = NULL;
	}

	for( std::vector< CGLRenderModel * >::iterator i = m_vecRenderModels.begin(); i != m_vecRenderModels.end(); i++ )
	{
		delete (*i);
	}
	m_vecRenderModels.clear();
	
	if( m_hasContext)
	{
		if (m_glSceneVertBuffer)
		{
			glDebugMessageControl( GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, nullptr, GL_FALSE );
			glDebugMessageCallback(nullptr, nullptr);
			glDeleteBuffers(1, &m_glSceneVertBuffer);
			glDeleteBuffers(1, &m_glIDVertBuffer);
			glDeleteBuffers(1, &m_glIDIndexBuffer);
		}

		if ( m_unSceneProgramID )
		{
			glDeleteProgram( m_unSceneProgramID );
		}
		if ( m_unControllerTransformProgramID )
		{
			glDeleteProgram( m_unControllerTransformProgramID );
		}
		if ( m_unRenderModelProgramID )
		{
			glDeleteProgram( m_unRenderModelProgramID );
		}
		if ( m_unLensProgramID )
		{
			glDeleteProgram( m_unLensProgramID );
		}

		glDeleteRenderbuffers( 1, &leftEyeDesc.m_nDepthBufferId );
		glDeleteTextures( 1, &leftEyeDesc.m_nRenderTextureId );
		glDeleteFramebuffers( 1, &leftEyeDesc.m_nRenderFramebufferId );
		glDeleteTextures( 1, &leftEyeDesc.m_nResolveTextureId );
		glDeleteFramebuffers( 1, &leftEyeDesc.m_nResolveFramebufferId );

		glDeleteRenderbuffers( 1, &rightEyeDesc.m_nDepthBufferId );
		glDeleteTextures( 1, &rightEyeDesc.m_nRenderTextureId );
		glDeleteFramebuffers( 1, &rightEyeDesc.m_nRenderFramebufferId );
		glDeleteTextures( 1, &rightEyeDesc.m_nResolveTextureId );
		glDeleteFramebuffers( 1, &rightEyeDesc.m_nResolveFramebufferId );

		if( m_unLensVAO != 0 )
		{
			glDeleteVertexArrays( 1, &m_unLensVAO );
		}
		if( m_unSceneVAO != 0 )
		{
			glDeleteVertexArrays( 1, &m_unSceneVAO );
		}
		if( m_unControllerVAO != 0 )
		{
			glDeleteVertexArrays( 1, &m_unControllerVAO );
		}
	}

	sExample->exitPhysics();
	delete sExample;

	delete m_app;
	m_app=0;
	
}


void CMainApplication::getControllerTransform(int unDevice, b3Transform& tr)
{
		const Matrix4 & matOrg = m_rmat4DevicePose[unDevice];
		tr.setIdentity();
		tr.setOrigin(b3MakeVector3(matOrg[12],matOrg[13],matOrg[14]));//pos[1]));
		b3Matrix3x3 bmat;
		for (int i=0;i<3;i++)
		{
			for (int j=0;j<3;j++)
			{
				bmat[i][j] = matOrg[i+4*j];
			}
		}
		tr.setBasis(bmat);
		b3Transform y2z;
		y2z.setIdentity();
		y2z.setRotation(b3Quaternion(0,B3_HALF_PI,0));
		tr = y2z*tr;
}
//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
bool CMainApplication::HandleInput()
{
	bool bRet = false;
	
	// Process SteamVR events
	vr::VREvent_t event;
	while( m_pHMD->PollNextEvent( &event, sizeof( event ) ) )
	{
		ProcessVREvent( event );
	}

	// Process SteamVR controller state
	for( vr::TrackedDeviceIndex_t unDevice = 0; unDevice < vr::k_unMaxTrackedDeviceCount; unDevice++ )
	{
		vr::VRControllerState_t state;
		if( m_pHMD->GetControllerState( unDevice, &state ) )
		{
			//we need to have the 'move' events, so no early out here
			//if (sPrevStates[unDevice].unPacketNum != state.unPacketNum)
			if( m_pHMD->GetTrackedDeviceClass( unDevice) == vr::TrackedDeviceClass_Controller )
			{
				sPrevStates[unDevice].unPacketNum = state.unPacketNum;

				for (int button = 0; button < vr::k_EButton_Max; button++)
				{
					uint64_t trigger = vr::ButtonMaskFromId((vr::EVRButtonId)button);

					bool isTrigger = (state.ulButtonPressed&trigger) != 0;
					if (isTrigger)
					{

						b3Transform tr;
						getControllerTransform(unDevice, tr);
						float pos[3] = { tr.getOrigin()[0], tr.getOrigin()[1], tr.getOrigin()[2] };
						b3Quaternion born = tr.getRotation();
						float orn[4] = { born[0], born[1], born[2], born[3] };

						//pressed now, not pressed before -> raise a button down event
						if ((sPrevStates[unDevice].ulButtonPressed&trigger)==0)
						{
//							printf("Device PRESSED: %d, button %d\n", unDevice, button);
							if (button==2)
							{
								glPolygonMode( GL_FRONT_AND_BACK, GL_LINE );
								///todo(erwincoumans) can't use reguar debug drawer, because physics/graphics are not in sync
								//add a special debug drawer that deals with this
								//gDebugDrawFlags = btIDebugDraw::DBG_DrawWireframe;// :DBG_DrawContactPoints
									//btIDebugDraw::DBG_DrawConstraintLimits+
									//btIDebugDraw::DBG_DrawConstraints
									;
							}

							sExample->vrControllerButtonCallback(unDevice, button, 1, pos, orn);

						}
						else
						{
							
//							printf("Device MOVED: %d\n", unDevice);
							sExample->vrControllerMoveCallback(unDevice, pos, orn, state.rAxis[1].x);
						}
					}
					else
					{
						if( m_pHMD->GetTrackedDeviceClass( unDevice) == vr::TrackedDeviceClass_Controller )
						{
							

							b3Transform tr;
							getControllerTransform(unDevice, tr);
							float pos[3] = { tr.getOrigin()[0], tr.getOrigin()[1], tr.getOrigin()[2] };
							b3Quaternion born = tr.getRotation();
							float orn[4] = { born[0], born[1], born[2], born[3] };
	//							printf("Device RELEASED: %d, button %d\n", unDevice,button);
					
							//not pressed now, but pressed before -> raise a button up event
							if ((sPrevStates[unDevice].ulButtonPressed&trigger) != 0)
							{
								if (button==2)
								{
									gDebugDrawFlags = 0;
									glPolygonMode( GL_FRONT_AND_BACK, GL_FILL);
								}
							
								sExample->vrControllerButtonCallback(unDevice, button, 0, pos, orn);
							} else
							{

								sExample->vrControllerMoveCallback(unDevice, pos, orn, state.rAxis[1].x);
							}
						}
					}
				}
			} 

			m_rbShowTrackedDevice[ unDevice ] = state.ulButtonPressed == 0;
		}
		sPrevStates[unDevice] = state;
	}

	return bRet;
}

//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------

void CMainApplication::RunMainLoop()
{
	bool bQuit = false;

	while ( !bQuit && !m_app->m_window->requestedExit())
	{
		bQuit = HandleInput();

		RenderFrame();
	}

}


//-----------------------------------------------------------------------------
// Purpose: Processes a single VR event
//-----------------------------------------------------------------------------
void CMainApplication::ProcessVREvent( const vr::VREvent_t & event )
{
	switch( event.eventType )
	{
	case vr::VREvent_TrackedDeviceActivated:
		{
			SetupRenderModelForTrackedDevice( event.trackedDeviceIndex );
			b3Printf( "Device %u attached. Setting up render model.\n", event.trackedDeviceIndex );
		}
		break;
	case vr::VREvent_TrackedDeviceDeactivated:
		{
			b3Printf( "Device %u detached.\n", event.trackedDeviceIndex );
		}
		break;
	case vr::VREvent_TrackedDeviceUpdated:
		{
			b3Printf( "Device %u updated.\n", event.trackedDeviceIndex );
		}
		break;
	}
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void CMainApplication::RenderFrame()
{
	// for now as fast as possible
	if ( m_pHMD )
	{
		DrawControllers();
		RenderStereoTargets();
		RenderDistortion();

		vr::Texture_t leftEyeTexture = {(void*)leftEyeDesc.m_nResolveTextureId, vr::API_OpenGL, vr::ColorSpace_Gamma };
		vr::VRCompositor()->Submit(vr::Eye_Left, &leftEyeTexture );
		vr::Texture_t rightEyeTexture = {(void*)rightEyeDesc.m_nResolveTextureId, vr::API_OpenGL, vr::ColorSpace_Gamma };
		vr::VRCompositor()->Submit(vr::Eye_Right, &rightEyeTexture );
	}

	if ( m_bVblank && m_bGlFinishHack )
	{
		//$ HACKHACK. From gpuview profiling, it looks like there is a bug where two renders and a present
		// happen right before and after the vsync causing all kinds of jittering issues. This glFinish()
		// appears to clear that up. Temporary fix while I try to get nvidia to investigate this problem.
		// 1/29/2014 mikesart
		glFinish();
	}

	// SwapWindow
	{
		m_app->swapBuffer();
		//SDL_GL_SwapWindow( m_pWindow );
		
	}

	// Clear
	{
		// We want to make sure the glFinish waits for the entire present to complete, not just the submission
		// of the command. So, we do a clear here right here so the glFinish will wait fully for the swap.
		glClearColor( 0, 0, 0, 1 );
		glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
	}

	// Flush and wait for swap.
	if ( m_bVblank )
	{
		glFlush();
		glFinish();
	}

	// Spew out the controller and pose count whenever they change.
	if ( m_iTrackedControllerCount != m_iTrackedControllerCount_Last || m_iValidPoseCount != m_iValidPoseCount_Last )
	{
		m_iValidPoseCount_Last = m_iValidPoseCount;
		m_iTrackedControllerCount_Last = m_iTrackedControllerCount;
		
		b3Printf( "PoseCount:%d(%s) Controllers:%d\n", m_iValidPoseCount, m_strPoseClasses.c_str(), m_iTrackedControllerCount );
	}

	UpdateHMDMatrixPose();
}


//-----------------------------------------------------------------------------
// Purpose: Compiles a GL shader program and returns the handle. Returns 0 if
//			the shader couldn't be compiled for some reason.
//-----------------------------------------------------------------------------
GLuint CMainApplication::CompileGLShader( const char *pchShaderName, const char *pchVertexShader, const char *pchFragmentShader )
{
	GLuint unProgramID = glCreateProgram();

	GLuint nSceneVertexShader = glCreateShader(GL_VERTEX_SHADER);
	glShaderSource( nSceneVertexShader, 1, &pchVertexShader, NULL);
	glCompileShader( nSceneVertexShader );

	GLint vShaderCompiled = GL_FALSE;
	glGetShaderiv( nSceneVertexShader, GL_COMPILE_STATUS, &vShaderCompiled);
	if ( vShaderCompiled != GL_TRUE)
	{
		b3Printf("%s - Unable to compile vertex shader %d!\n", pchShaderName, nSceneVertexShader);
		glDeleteProgram( unProgramID );
		glDeleteShader( nSceneVertexShader );
		return 0;
	}
	glAttachShader( unProgramID, nSceneVertexShader);
	glDeleteShader( nSceneVertexShader ); // the program hangs onto this once it's attached

	GLuint  nSceneFragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
	glShaderSource( nSceneFragmentShader, 1, &pchFragmentShader, NULL);
	glCompileShader( nSceneFragmentShader );

	GLint fShaderCompiled = GL_FALSE;
	glGetShaderiv( nSceneFragmentShader, GL_COMPILE_STATUS, &fShaderCompiled);
	if (fShaderCompiled != GL_TRUE)
	{
		b3Printf("%s - Unable to compile fragment shader %d!\n", pchShaderName, nSceneFragmentShader );
		glDeleteProgram( unProgramID );
		glDeleteShader( nSceneFragmentShader );
		return 0;	
	}

	glAttachShader( unProgramID, nSceneFragmentShader );
	glDeleteShader( nSceneFragmentShader ); // the program hangs onto this once it's attached

	glLinkProgram( unProgramID );

	GLint programSuccess = GL_TRUE;
	glGetProgramiv( unProgramID, GL_LINK_STATUS, &programSuccess);
	if ( programSuccess != GL_TRUE )
	{
		b3Printf("%s - Error linking program %d!\n", pchShaderName, unProgramID);
		glDeleteProgram( unProgramID );
		return 0;
	}

	glUseProgram( unProgramID );
	glUseProgram( 0 );

	return unProgramID;
}


//-----------------------------------------------------------------------------
// Purpose: Creates all the shaders used by HelloVR SDL
//-----------------------------------------------------------------------------
bool CMainApplication::CreateAllShaders()
{
	m_unSceneProgramID = CompileGLShader( 
		"Scene",

		// Vertex Shader
		"#version 410\n"
		"uniform mat4 matrix;\n"
		"layout(location = 0) in vec4 position;\n"
		"layout(location = 1) in vec2 v2UVcoordsIn;\n"
		"layout(location = 2) in vec3 v3NormalIn;\n"
		"out vec2 v2UVcoords;\n"
		"void main()\n"
		"{\n"
		"	v2UVcoords = v2UVcoordsIn;\n"
		"	gl_Position = matrix * position;\n"
		"}\n",

		// Fragment Shader
		"#version 410 core\n"
		"uniform sampler2D mytexture;\n"
		"in vec2 v2UVcoords;\n"
		"out vec4 outputColor;\n"
		"void main()\n"
		"{\n"
		"   outputColor = texture(mytexture, v2UVcoords);\n"
		"}\n"
		);
	m_nSceneMatrixLocation = glGetUniformLocation( m_unSceneProgramID, "matrix" );
	if( m_nSceneMatrixLocation == -1 )
	{
		b3Printf( "Unable to find matrix uniform in scene shader\n" );
		return false;
	}

	m_unControllerTransformProgramID = CompileGLShader(
		"Controller",

		// vertex shader
		"#version 410\n"
		"uniform mat4 matrix;\n"
		"layout(location = 0) in vec4 position;\n"
		"layout(location = 1) in vec3 v3ColorIn;\n"
		"out vec4 v4Color;\n"
		"void main()\n"
		"{\n"
		"	v4Color.xyz = v3ColorIn; v4Color.a = 1.0;\n"
		"	gl_Position = matrix * position;\n"
		"}\n",

		// fragment shader
		"#version 410\n"
		"in vec4 v4Color;\n"
		"out vec4 outputColor;\n"
		"void main()\n"
		"{\n"
		"   outputColor = v4Color;\n"
		"}\n"
		);
	m_nControllerMatrixLocation = glGetUniformLocation( m_unControllerTransformProgramID, "matrix" );
	if( m_nControllerMatrixLocation == -1 )
	{
		b3Printf( "Unable to find matrix uniform in controller shader\n" );
		return false;
	}

	m_unRenderModelProgramID = CompileGLShader( 
		"render model",

		// vertex shader
		"#version 410\n"
		"uniform mat4 matrix;\n"
		"layout(location = 0) in vec4 position;\n"
		"layout(location = 1) in vec3 v3NormalIn;\n"
		"layout(location = 2) in vec2 v2TexCoordsIn;\n"
		"out vec2 v2TexCoord;\n"
		"void main()\n"
		"{\n"
		"	v2TexCoord = v2TexCoordsIn;\n"
		"	gl_Position = matrix * vec4(position.xyz, 1);\n"
		"}\n",

		//fragment shader
		"#version 410 core\n"
		"uniform sampler2D diffuse;\n"
		"in vec2 v2TexCoord;\n"
		"out vec4 outputColor;\n"
		"void main()\n"
		"{\n"
		"   outputColor = texture( diffuse, v2TexCoord);\n"
		"}\n"

		);
	m_nRenderModelMatrixLocation = glGetUniformLocation( m_unRenderModelProgramID, "matrix" );
	if( m_nRenderModelMatrixLocation == -1 )
	{
		b3Printf( "Unable to find matrix uniform in render model shader\n" );
		return false;
	}

	m_unLensProgramID = CompileGLShader(
		"Distortion",

		// vertex shader
		"#version 410 core\n"
		"layout(location = 0) in vec4 position;\n"
		"layout(location = 1) in vec2 v2UVredIn;\n"
		"layout(location = 2) in vec2 v2UVGreenIn;\n"
		"layout(location = 3) in vec2 v2UVblueIn;\n"
		"noperspective  out vec2 v2UVred;\n"
		"noperspective  out vec2 v2UVgreen;\n"
		"noperspective  out vec2 v2UVblue;\n"
		"void main()\n"
		"{\n"
		"	v2UVred = v2UVredIn;\n"
		"	v2UVgreen = v2UVGreenIn;\n"
		"	v2UVblue = v2UVblueIn;\n"
		"	gl_Position = position;\n"
		"}\n",

		// fragment shader
		"#version 410 core\n"
		"uniform sampler2D mytexture;\n"

		"noperspective  in vec2 v2UVred;\n"
		"noperspective  in vec2 v2UVgreen;\n"
		"noperspective  in vec2 v2UVblue;\n"

		"out vec4 outputColor;\n"

		"void main()\n"
		"{\n"
		"	float fBoundsCheck = ( (dot( vec2( lessThan( v2UVgreen.xy, vec2(0.05, 0.05)) ), vec2(1.0, 1.0))+dot( vec2( greaterThan( v2UVgreen.xy, vec2( 0.95, 0.95)) ), vec2(1.0, 1.0))) );\n"
		"	if( fBoundsCheck > 1.0 )\n"
		"	{ outputColor = vec4( 0, 0, 0, 1.0 ); }\n"
		"	else\n"
		"	{\n"
		"		float red = texture(mytexture, v2UVred).x;\n"
		"		float green = texture(mytexture, v2UVgreen).y;\n"
		"		float blue = texture(mytexture, v2UVblue).z;\n"
		"		outputColor = vec4( red, green, blue, 1.0  ); }\n"
		"}\n"
		);


	return m_unSceneProgramID != 0 
		&& m_unControllerTransformProgramID != 0
		&& m_unRenderModelProgramID != 0
		&& m_unLensProgramID != 0;
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
bool CMainApplication::SetupTexturemaps()
{
	std::string sExecutableDirectory = Path_StripFilename( Path_GetExecutablePath() );
	std::string strFullPath = Path_MakeAbsolute( "../cube_texture.png", sExecutableDirectory );
	
	std::vector<unsigned char> imageRGBA;
	unsigned nImageWidth, nImageHeight;
	unsigned nError = lodepng::decode( imageRGBA, nImageWidth, nImageHeight, strFullPath.c_str() );
	
	if ( nError != 0 )
		return false;

	glGenTextures(1, &m_iTexture );
	glBindTexture( GL_TEXTURE_2D, m_iTexture );

	glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, nImageWidth, nImageHeight,
		0, GL_RGBA, GL_UNSIGNED_BYTE, &imageRGBA[0] );

	glGenerateMipmap(GL_TEXTURE_2D);

	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR );

	GLfloat fLargest;
	glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &fLargest);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, fLargest);
	 	
	glBindTexture( GL_TEXTURE_2D, 0 );

	return ( m_iTexture != 0 );
}


//-----------------------------------------------------------------------------
// Purpose: create a sea of cubes
//-----------------------------------------------------------------------------
void CMainApplication::SetupScene()
{
	if ( !m_pHMD )
		return;

	std::vector<float> vertdataarray;

	Matrix4 matScale;
	matScale.scale( m_fScale, m_fScale, m_fScale );
	Matrix4 matTransform;
	matTransform.translate(
		-( (float)m_iSceneVolumeWidth * m_fScaleSpacing ) / 2.f,
		-( (float)m_iSceneVolumeHeight * m_fScaleSpacing ) / 2.f,
		-( (float)m_iSceneVolumeDepth * m_fScaleSpacing ) / 2.f);
	
	Matrix4 mat = matScale * matTransform;

	for( int z = 0; z< m_iSceneVolumeDepth; z++ )
	{
		for( int y = 0; y< m_iSceneVolumeHeight; y++ )
		{
			for( int x = 0; x< m_iSceneVolumeWidth; x++ )
			{
				AddCubeToScene( mat, vertdataarray );
				mat = mat * Matrix4().translate( m_fScaleSpacing, 0, 0 );
			}
			mat = mat * Matrix4().translate( -((float)m_iSceneVolumeWidth) * m_fScaleSpacing, m_fScaleSpacing, 0 );
		}
		mat = mat * Matrix4().translate( 0, -((float)m_iSceneVolumeHeight) * m_fScaleSpacing, m_fScaleSpacing );
	}
	m_uiVertcount = vertdataarray.size()/5;
	
	glGenVertexArrays( 1, &m_unSceneVAO );
	glBindVertexArray( m_unSceneVAO );

	glGenBuffers( 1, &m_glSceneVertBuffer );
	glBindBuffer( GL_ARRAY_BUFFER, m_glSceneVertBuffer );
	glBufferData( GL_ARRAY_BUFFER, sizeof(float) * vertdataarray.size(), &vertdataarray[0], GL_STATIC_DRAW);

	glBindBuffer( GL_ARRAY_BUFFER, m_glSceneVertBuffer );

	GLsizei stride = sizeof(VertexDataScene);
	uintptr_t offset = 0;

	glEnableVertexAttribArray( 0 );
	glVertexAttribPointer( 0, 3, GL_FLOAT, GL_FALSE, stride , (const void *)offset);

	offset += sizeof(Vector3);
	glEnableVertexAttribArray( 1 );
	glVertexAttribPointer( 1, 2, GL_FLOAT, GL_FALSE, stride, (const void *)offset);

	glBindVertexArray( 0 );
	glDisableVertexAttribArray(0);
	glDisableVertexAttribArray(1);

	m_hasContext = true;
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void CMainApplication::AddCubeVertex( float fl0, float fl1, float fl2, float fl3, float fl4, std::vector<float> &vertdata )
{
	vertdata.push_back( fl0 );
	vertdata.push_back( fl1 );
	vertdata.push_back( fl2 );
	vertdata.push_back( fl3 );
	vertdata.push_back( fl4 );
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void CMainApplication::AddCubeToScene( Matrix4 mat, std::vector<float> &vertdata )
{
	// Matrix4 mat( outermat.data() );

	Vector4 A = mat * Vector4( 0, 0, 0, 1 );
	Vector4 B = mat * Vector4( 1, 0, 0, 1 );
	Vector4 C = mat * Vector4( 1, 1, 0, 1 );
	Vector4 D = mat * Vector4( 0, 1, 0, 1 );
	Vector4 E = mat * Vector4( 0, 0, 1, 1 );
	Vector4 F = mat * Vector4( 1, 0, 1, 1 );
	Vector4 G = mat * Vector4( 1, 1, 1, 1 );
	Vector4 H = mat * Vector4( 0, 1, 1, 1 );

	// triangles instead of quads
	AddCubeVertex( E.x, E.y, E.z, 0, 1, vertdata ); //Front
	AddCubeVertex( F.x, F.y, F.z, 1, 1, vertdata );
	AddCubeVertex( G.x, G.y, G.z, 1, 0, vertdata );
	AddCubeVertex( G.x, G.y, G.z, 1, 0, vertdata );
	AddCubeVertex( H.x, H.y, H.z, 0, 0, vertdata );
	AddCubeVertex( E.x, E.y, E.z, 0, 1, vertdata );
					 
	AddCubeVertex( B.x, B.y, B.z, 0, 1, vertdata ); //Back
	AddCubeVertex( A.x, A.y, A.z, 1, 1, vertdata );
	AddCubeVertex( D.x, D.y, D.z, 1, 0, vertdata );
	AddCubeVertex( D.x, D.y, D.z, 1, 0, vertdata );
	AddCubeVertex( C.x, C.y, C.z, 0, 0, vertdata );
	AddCubeVertex( B.x, B.y, B.z, 0, 1, vertdata );
					
	AddCubeVertex( H.x, H.y, H.z, 0, 1, vertdata ); //Top
	AddCubeVertex( G.x, G.y, G.z, 1, 1, vertdata );
	AddCubeVertex( C.x, C.y, C.z, 1, 0, vertdata );
	AddCubeVertex( C.x, C.y, C.z, 1, 0, vertdata );
	AddCubeVertex( D.x, D.y, D.z, 0, 0, vertdata );
	AddCubeVertex( H.x, H.y, H.z, 0, 1, vertdata );
				
	AddCubeVertex( A.x, A.y, A.z, 0, 1, vertdata ); //Bottom
	AddCubeVertex( B.x, B.y, B.z, 1, 1, vertdata );
	AddCubeVertex( F.x, F.y, F.z, 1, 0, vertdata );
	AddCubeVertex( F.x, F.y, F.z, 1, 0, vertdata );
	AddCubeVertex( E.x, E.y, E.z, 0, 0, vertdata );
	AddCubeVertex( A.x, A.y, A.z, 0, 1, vertdata );
					
	AddCubeVertex( A.x, A.y, A.z, 0, 1, vertdata ); //Left
	AddCubeVertex( E.x, E.y, E.z, 1, 1, vertdata );
	AddCubeVertex( H.x, H.y, H.z, 1, 0, vertdata );
	AddCubeVertex( H.x, H.y, H.z, 1, 0, vertdata );
	AddCubeVertex( D.x, D.y, D.z, 0, 0, vertdata );
	AddCubeVertex( A.x, A.y, A.z, 0, 1, vertdata );

	AddCubeVertex( F.x, F.y, F.z, 0, 1, vertdata ); //Right
	AddCubeVertex( B.x, B.y, B.z, 1, 1, vertdata );
	AddCubeVertex( C.x, C.y, C.z, 1, 0, vertdata );
	AddCubeVertex( C.x, C.y, C.z, 1, 0, vertdata );
	AddCubeVertex( G.x, G.y, G.z, 0, 0, vertdata );
	AddCubeVertex( F.x, F.y, F.z, 0, 1, vertdata );
}


//-----------------------------------------------------------------------------
// Purpose: Draw all of the controllers as X/Y/Z lines
//-----------------------------------------------------------------------------
void CMainApplication::DrawControllers()
{
	// don't draw controllers if somebody else has input focus
	if( m_pHMD->IsInputFocusCapturedByAnotherProcess() )
		return;

	std::vector<float> vertdataarray;

	m_uiControllerVertcount = 0;
	m_iTrackedControllerCount = 0;

	for ( vr::TrackedDeviceIndex_t unTrackedDevice = vr::k_unTrackedDeviceIndex_Hmd + 1; unTrackedDevice < vr::k_unMaxTrackedDeviceCount; ++unTrackedDevice )
	{
		if ( !m_pHMD->IsTrackedDeviceConnected( unTrackedDevice ) )
			continue;

		if( m_pHMD->GetTrackedDeviceClass( unTrackedDevice ) != vr::TrackedDeviceClass_Controller )
			continue;

		m_iTrackedControllerCount += 1;

		if( !m_rTrackedDevicePose[ unTrackedDevice ].bPoseIsValid )
			continue;

		const Matrix4 & mat = m_rmat4DevicePose[unTrackedDevice];

		Vector4 center = mat * Vector4( 0, 0, 0, 1 );

		for ( int i = 0; i < 3; ++i )
		{
			Vector3 color( 0, 0, 0 );
			Vector4 point( 0, 0, 0, 1 );
			point[i] += 0.05f;  // offset in X, Y, Z
			color[i] = 1.0;  // R, G, B
			point = mat * point;
			vertdataarray.push_back( center.x );
			vertdataarray.push_back( center.y );
			vertdataarray.push_back( center.z );

			vertdataarray.push_back( color.x );
			vertdataarray.push_back( color.y );
			vertdataarray.push_back( color.z );
		
			vertdataarray.push_back( point.x );
			vertdataarray.push_back( point.y );
			vertdataarray.push_back( point.z );
		
			vertdataarray.push_back( color.x );
			vertdataarray.push_back( color.y );
			vertdataarray.push_back( color.z );
		
			m_uiControllerVertcount += 2;
		}

		Vector4 start = mat * Vector4( 0, 0, -0.02f, 1 );
		Vector4 end = mat * Vector4( 0, 0, -39.f, 1 );
		Vector3 color( .92f, .92f, .71f );

		vertdataarray.push_back( start.x );vertdataarray.push_back( start.y );vertdataarray.push_back( start.z );
		vertdataarray.push_back( color.x );vertdataarray.push_back( color.y );vertdataarray.push_back( color.z );

		vertdataarray.push_back( end.x );vertdataarray.push_back( end.y );vertdataarray.push_back( end.z );
		vertdataarray.push_back( color.x );vertdataarray.push_back( color.y );vertdataarray.push_back( color.z );
		m_uiControllerVertcount += 2;
	}

	// Setup the VAO the first time through.
	if ( m_unControllerVAO == 0 )
	{
		glGenVertexArrays( 1, &m_unControllerVAO );
		glBindVertexArray( m_unControllerVAO );

		glGenBuffers( 1, &m_glControllerVertBuffer );
		glBindBuffer( GL_ARRAY_BUFFER, m_glControllerVertBuffer );

		GLuint stride = 2 * 3 * sizeof( float );
		GLuint offset = 0;

		glEnableVertexAttribArray( 0 );
		glVertexAttribPointer( 0, 3, GL_FLOAT, GL_FALSE, stride, (const void *)offset);

		offset += sizeof( Vector3 );
		glEnableVertexAttribArray( 1 );
		glVertexAttribPointer( 1, 3, GL_FLOAT, GL_FALSE, stride, (const void *)offset);

		glBindVertexArray( 0 );
	}

	glBindBuffer( GL_ARRAY_BUFFER, m_glControllerVertBuffer );

	// set vertex data if we have some
	if( vertdataarray.size() > 0 )
	{
		//$ TODO: Use glBufferSubData for this...
		glBufferData( GL_ARRAY_BUFFER, sizeof(float) * vertdataarray.size(), &vertdataarray[0], GL_STREAM_DRAW );
	}
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void CMainApplication::SetupCameras()
{
	m_mat4ProjectionLeft = GetHMDMatrixProjectionEye( vr::Eye_Left );
	m_mat4ProjectionRight = GetHMDMatrixProjectionEye( vr::Eye_Right );
	m_mat4eyePosLeft = GetHMDMatrixPoseEye( vr::Eye_Left );
	m_mat4eyePosRight = GetHMDMatrixPoseEye( vr::Eye_Right );
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
bool CMainApplication::CreateFrameBuffer( int nWidth, int nHeight, FramebufferDesc &framebufferDesc )
{
	glGenFramebuffers(1, &framebufferDesc.m_nRenderFramebufferId );
	glBindFramebuffer(GL_FRAMEBUFFER, framebufferDesc.m_nRenderFramebufferId);

	glGenRenderbuffers(1, &framebufferDesc.m_nDepthBufferId);
	glBindRenderbuffer(GL_RENDERBUFFER, framebufferDesc.m_nDepthBufferId);
	glRenderbufferStorageMultisample(GL_RENDERBUFFER, 4, GL_DEPTH_COMPONENT, nWidth, nHeight );
	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER,	framebufferDesc.m_nDepthBufferId );

	glGenTextures(1, &framebufferDesc.m_nRenderTextureId );
	glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, framebufferDesc.m_nRenderTextureId );
	glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, 4, GL_RGBA8, nWidth, nHeight, true);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D_MULTISAMPLE, framebufferDesc.m_nRenderTextureId, 0);

	glGenFramebuffers(1, &framebufferDesc.m_nResolveFramebufferId );
	glBindFramebuffer(GL_FRAMEBUFFER, framebufferDesc.m_nResolveFramebufferId);

	glGenTextures(1, &framebufferDesc.m_nResolveTextureId );
	glBindTexture(GL_TEXTURE_2D, framebufferDesc.m_nResolveTextureId );
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 0);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, nWidth, nHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, framebufferDesc.m_nResolveTextureId, 0);

	// check FBO status
	GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
	if (status != GL_FRAMEBUFFER_COMPLETE)
	{
		return false;
	}

	glBindFramebuffer( GL_FRAMEBUFFER, 0 );

	return true;
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
bool CMainApplication::SetupStereoRenderTargets()
{
	if ( !m_pHMD )
		return false;

	m_pHMD->GetRecommendedRenderTargetSize( &m_nRenderWidth, &m_nRenderHeight );

	CreateFrameBuffer( m_nRenderWidth, m_nRenderHeight, leftEyeDesc );
	CreateFrameBuffer( m_nRenderWidth, m_nRenderHeight, rightEyeDesc );
	
	return true;
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void CMainApplication::SetupDistortion()
{
	if ( !m_pHMD )
		return;

	GLushort m_iLensGridSegmentCountH = 43;
	GLushort m_iLensGridSegmentCountV = 43;

	float w = (float)( 1.0/float(m_iLensGridSegmentCountH-1));
	float h = (float)( 1.0/float(m_iLensGridSegmentCountV-1));

	float u, v = 0;

	std::vector<VertexDataLens> vVerts(0);
	VertexDataLens vert;

	//left eye distortion verts
	float Xoffset = -1;
	for( int y=0; y<m_iLensGridSegmentCountV; y++ )
	{
		for( int x=0; x<m_iLensGridSegmentCountH; x++ )
		{
			u = x*w; v = 1-y*h;
			vert.position = Vector2( Xoffset+u, -1+2*y*h );

			vr::DistortionCoordinates_t dc0 = m_pHMD->ComputeDistortion(vr::Eye_Left, u, v);

			vert.texCoordRed = Vector2(dc0.rfRed[0], 1 - dc0.rfRed[1]);
			vert.texCoordGreen =  Vector2(dc0.rfGreen[0], 1 - dc0.rfGreen[1]);
			vert.texCoordBlue = Vector2(dc0.rfBlue[0], 1 - dc0.rfBlue[1]);

			vVerts.push_back( vert );
		}
	}

	//right eye distortion verts
	Xoffset = 0;
	for( int y=0; y<m_iLensGridSegmentCountV; y++ )
	{
		for( int x=0; x<m_iLensGridSegmentCountH; x++ )
		{
			u = x*w; v = 1-y*h;
			vert.position = Vector2( Xoffset+u, -1+2*y*h );

			vr::DistortionCoordinates_t dc0 = m_pHMD->ComputeDistortion( vr::Eye_Right, u, v );

			vert.texCoordRed = Vector2(dc0.rfRed[0], 1 - dc0.rfRed[1]);
			vert.texCoordGreen = Vector2(dc0.rfGreen[0], 1 - dc0.rfGreen[1]);
			vert.texCoordBlue = Vector2(dc0.rfBlue[0], 1 - dc0.rfBlue[1]);

			vVerts.push_back( vert );
		}
	}

	std::vector<GLushort> vIndices;
	GLushort a,b,c,d;

	GLushort offset = 0;
	for( GLushort y=0; y<m_iLensGridSegmentCountV-1; y++ )
	{
		for( GLushort x=0; x<m_iLensGridSegmentCountH-1; x++ )
		{
			a = m_iLensGridSegmentCountH*y+x +offset;
			b = m_iLensGridSegmentCountH*y+x+1 +offset;
			c = (y+1)*m_iLensGridSegmentCountH+x+1 +offset;
			d = (y+1)*m_iLensGridSegmentCountH+x +offset;
			vIndices.push_back( a );
			vIndices.push_back( b );
			vIndices.push_back( c );

			vIndices.push_back( a );
			vIndices.push_back( c );
			vIndices.push_back( d );
		}
	}

	offset = (m_iLensGridSegmentCountH)*(m_iLensGridSegmentCountV);
	for( GLushort y=0; y<m_iLensGridSegmentCountV-1; y++ )
	{
		for( GLushort x=0; x<m_iLensGridSegmentCountH-1; x++ )
		{
			a = m_iLensGridSegmentCountH*y+x +offset;
			b = m_iLensGridSegmentCountH*y+x+1 +offset;
			c = (y+1)*m_iLensGridSegmentCountH+x+1 +offset;
			d = (y+1)*m_iLensGridSegmentCountH+x +offset;
			vIndices.push_back( a );
			vIndices.push_back( b );
			vIndices.push_back( c );

			vIndices.push_back( a );
			vIndices.push_back( c );
			vIndices.push_back( d );
		}
	}
	m_uiIndexSize = vIndices.size();

	glGenVertexArrays( 1, &m_unLensVAO );
	glBindVertexArray( m_unLensVAO );

	glGenBuffers( 1, &m_glIDVertBuffer );
	glBindBuffer( GL_ARRAY_BUFFER, m_glIDVertBuffer );
	glBufferData( GL_ARRAY_BUFFER, vVerts.size()*sizeof(VertexDataLens), &vVerts[0], GL_STATIC_DRAW );

	glGenBuffers( 1, &m_glIDIndexBuffer );
	glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, m_glIDIndexBuffer );
	glBufferData( GL_ELEMENT_ARRAY_BUFFER, vIndices.size()*sizeof(GLushort), &vIndices[0], GL_STATIC_DRAW );

	glEnableVertexAttribArray( 0 );
	glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(VertexDataLens), (void *)offsetof( VertexDataLens, position ) );

	glEnableVertexAttribArray( 1 );
	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(VertexDataLens), (void *)offsetof( VertexDataLens, texCoordRed ) );

	glEnableVertexAttribArray(2);
	glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(VertexDataLens), (void *)offsetof( VertexDataLens, texCoordGreen ) );

	glEnableVertexAttribArray(3);
	glVertexAttribPointer(3, 2, GL_FLOAT, GL_FALSE, sizeof(VertexDataLens), (void *)offsetof( VertexDataLens, texCoordBlue ) );

	glBindVertexArray( 0 );

	glDisableVertexAttribArray(0);
	glDisableVertexAttribArray(1);
	glDisableVertexAttribArray(2);
	glDisableVertexAttribArray(3);

	glBindBuffer(GL_ARRAY_BUFFER, 0);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void CMainApplication::RenderStereoTargets()
{
	sExample->stepSimulation(1./60.);

	glClearColor( 0.15f, 0.15f, 0.18f, 1.0f ); // nice background color, but not black
	glEnable( GL_MULTISAMPLE );


	m_app->m_instancingRenderer->init();
	
	
	Matrix4 rotYtoZ = rotYtoZ.identity();
	
	//some Bullet apps (especially robotics related) require Z as up-axis)
	if (m_app->getUpAxis()==2)
	{
		rotYtoZ.rotateX(-90);
	}
	
	

	// Left Eye
	{
		
		Matrix4 viewMatLeft = m_mat4eyePosLeft * m_mat4HMDPose * rotYtoZ;
		Matrix4 viewMatCenter = m_mat4HMDPose * rotYtoZ;
		//0,1,2,3
		//4,5,6,7,
		//8,9,10,11
		//12,13,14,15
		
		//m_mat4eyePosLeft.get()[10]
		//m_app->m_instancingRenderer->getActiveCamera()->setCameraTargetPosition(
		//	m_mat4eyePosLeft.get()[3],
		//	m_mat4eyePosLeft.get()[7],
		//	m_mat4eyePosLeft.get()[11]);
		Matrix4 m;
		m = viewMatCenter;
		const float* mat = m.invertAffine().get();
		
		/*printf("camera:\n,%f,%f,%f,%f\n%f,%f,%f,%f\n%f,%f,%f,%f\n%f,%f,%f,%f",
			mat[0],mat[1],mat[2],mat[3],
			mat[4],mat[5],mat[6],mat[7],
			mat[8],mat[9],mat[10],mat[11],
			mat[12],mat[13],mat[14],mat[15]);
			*/
		float dist=1;
		m_app->m_instancingRenderer->getActiveCamera()->setCameraTargetPosition(
			mat[12]-dist*mat[8],
			mat[13]-dist*mat[9],
			mat[14]-dist*mat[10]
			);
		m_app->m_instancingRenderer->getActiveCamera()->setCameraUpVector(mat[0],mat[1],mat[2]);
		m_app->m_instancingRenderer->getActiveCamera()->setVRCamera(viewMatLeft.get(),m_mat4ProjectionLeft.get());
		m_app->m_instancingRenderer->updateCamera(m_app->getUpAxis());
	}

	glBindFramebuffer( GL_FRAMEBUFFER, leftEyeDesc.m_nRenderFramebufferId );
 	glViewport(0, 0, m_nRenderWidth, m_nRenderHeight );
 	
	
	

	m_app->m_window->startRendering();
	

	RenderScene( vr::Eye_Left );

	
	

	
	m_app->m_instancingRenderer->setRenderFrameBuffer((unsigned int)leftEyeDesc.m_nRenderFramebufferId);

	if (gDebugDrawFlags)
	{
		sExample->physicsDebugDraw(gDebugDrawFlags);
	} 
	
	{
		sExample->renderScene();
	}

	//m_app->m_instancingRenderer->renderScene();
	DrawGridData gridUp;
	gridUp.upAxis = m_app->getUpAxis();
//	m_app->drawGrid(gridUp);

	
 	glBindFramebuffer( GL_FRAMEBUFFER, 0 );
	
	glDisable( GL_MULTISAMPLE );
	 	
 	glBindFramebuffer(GL_READ_FRAMEBUFFER, leftEyeDesc.m_nRenderFramebufferId);
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, leftEyeDesc.m_nResolveFramebufferId );

    glBlitFramebuffer( 0, 0, m_nRenderWidth, m_nRenderHeight, 0, 0, m_nRenderWidth, m_nRenderHeight, 
		GL_COLOR_BUFFER_BIT,
 		GL_LINEAR );

 	glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0 );	

	glEnable( GL_MULTISAMPLE );

	// Right Eye
	
	

	{
		Matrix4 viewMatRight = m_mat4eyePosRight * m_mat4HMDPose * rotYtoZ;
		m_app->m_instancingRenderer->getActiveCamera()->setVRCamera(viewMatRight.get(),m_mat4ProjectionRight.get());
		m_app->m_instancingRenderer->updateCamera(m_app->getUpAxis());
	}
	
	glBindFramebuffer( GL_FRAMEBUFFER, rightEyeDesc.m_nRenderFramebufferId );
 	glViewport(0, 0, m_nRenderWidth, m_nRenderHeight );
 	
	m_app->m_window->startRendering();
	
	RenderScene( vr::Eye_Right );
	
	m_app->m_instancingRenderer->setRenderFrameBuffer((unsigned int)rightEyeDesc.m_nRenderFramebufferId);
	//m_app->m_renderer->renderScene();
	
	if (gDebugDrawFlags)
	{
		sExample->physicsDebugDraw(gDebugDrawFlags);
	} 

	{
		sExample->renderScene();
	}

	//m_app->drawGrid(gridUp);
	
 	glBindFramebuffer( GL_FRAMEBUFFER, 0 );
 	
	glDisable( GL_MULTISAMPLE );

 	glBindFramebuffer(GL_READ_FRAMEBUFFER, rightEyeDesc.m_nRenderFramebufferId );
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, rightEyeDesc.m_nResolveFramebufferId );
	
    glBlitFramebuffer( 0, 0, m_nRenderWidth, m_nRenderHeight, 0, 0, m_nRenderWidth, m_nRenderHeight, 
		GL_COLOR_BUFFER_BIT,
 		GL_LINEAR  );

 	glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0 );
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void CMainApplication::RenderScene( vr::Hmd_Eye nEye )
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glEnable(GL_DEPTH_TEST);

	if( m_bShowCubes )
	{
		glUseProgram( m_unSceneProgramID );
		glUniformMatrix4fv( m_nSceneMatrixLocation, 1, GL_FALSE, GetCurrentViewProjectionMatrix( nEye ).get() );
		glBindVertexArray( m_unSceneVAO );
		glBindTexture( GL_TEXTURE_2D, m_iTexture );
		glDrawArrays( GL_TRIANGLES, 0, m_uiVertcount );
		glBindVertexArray( 0 );
	}

	bool bIsInputCapturedByAnotherProcess = m_pHMD->IsInputFocusCapturedByAnotherProcess();

	if( !bIsInputCapturedByAnotherProcess )
	{
		// draw the controller axis lines
		glUseProgram( m_unControllerTransformProgramID );
		glUniformMatrix4fv( m_nControllerMatrixLocation, 1, GL_FALSE, GetCurrentViewProjectionMatrix( nEye ).get() );
		glBindVertexArray( m_unControllerVAO );
		glDrawArrays( GL_LINES, 0, m_uiControllerVertcount );
		glBindVertexArray( 0 );
	}

	// ----- Render Model rendering -----
	glUseProgram( m_unRenderModelProgramID );

	for( uint32_t unTrackedDevice = 0; unTrackedDevice < vr::k_unMaxTrackedDeviceCount; unTrackedDevice++ )
	{
		if( !m_rTrackedDeviceToRenderModel[ unTrackedDevice ] || !m_rbShowTrackedDevice[ unTrackedDevice ] )
			continue;

		const vr::TrackedDevicePose_t & pose = m_rTrackedDevicePose[ unTrackedDevice ];
		if( !pose.bPoseIsValid )
			continue;

		if( bIsInputCapturedByAnotherProcess && m_pHMD->GetTrackedDeviceClass( unTrackedDevice ) == vr::TrackedDeviceClass_Controller )
			continue;

		const Matrix4 & matDeviceToTracking = m_rmat4DevicePose[ unTrackedDevice ];
		Matrix4 matMVP = GetCurrentViewProjectionMatrix( nEye ) * matDeviceToTracking;
		glUniformMatrix4fv( m_nRenderModelMatrixLocation, 1, GL_FALSE, matMVP.get() );

		m_rTrackedDeviceToRenderModel[ unTrackedDevice ]->Draw();
	}

	glUseProgram( 0 );
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void CMainApplication::RenderDistortion()
{
	glDisable(GL_DEPTH_TEST);
	glViewport( 0, 0, m_nWindowWidth, m_nWindowHeight );

	glBindVertexArray( m_unLensVAO );
	glUseProgram( m_unLensProgramID );

	//render left lens (first half of index array )
	glBindTexture(GL_TEXTURE_2D, leftEyeDesc.m_nResolveTextureId );
	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR );
	glDrawElements( GL_TRIANGLES, m_uiIndexSize/2, GL_UNSIGNED_SHORT, 0 );

	//render right lens (second half of index array )
	glBindTexture(GL_TEXTURE_2D, rightEyeDesc.m_nResolveTextureId  );
	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR );
	glDrawElements( GL_TRIANGLES, m_uiIndexSize/2, GL_UNSIGNED_SHORT, (const void *)(m_uiIndexSize) );

	glBindVertexArray( 0 );
	glUseProgram( 0 );
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
Matrix4 CMainApplication::GetHMDMatrixProjectionEye( vr::Hmd_Eye nEye )
{
	if ( !m_pHMD )
		return Matrix4();

	vr::HmdMatrix44_t mat = m_pHMD->GetProjectionMatrix( nEye, m_fNearClip, m_fFarClip, vr::API_OpenGL);

	return Matrix4(
		mat.m[0][0], mat.m[1][0], mat.m[2][0], mat.m[3][0],
		mat.m[0][1], mat.m[1][1], mat.m[2][1], mat.m[3][1], 
		mat.m[0][2], mat.m[1][2], mat.m[2][2], mat.m[3][2], 
		mat.m[0][3], mat.m[1][3], mat.m[2][3], mat.m[3][3]
	);
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
Matrix4 CMainApplication::GetHMDMatrixPoseEye( vr::Hmd_Eye nEye )
{
	if ( !m_pHMD )
		return Matrix4();

	vr::HmdMatrix34_t matEyeRight = m_pHMD->GetEyeToHeadTransform( nEye );
	Matrix4 matrixObj(
		matEyeRight.m[0][0], matEyeRight.m[1][0], matEyeRight.m[2][0], 0.0, 
		matEyeRight.m[0][1], matEyeRight.m[1][1], matEyeRight.m[2][1], 0.0,
		matEyeRight.m[0][2], matEyeRight.m[1][2], matEyeRight.m[2][2], 0.0,
		matEyeRight.m[0][3], matEyeRight.m[1][3], matEyeRight.m[2][3], 1.0f
		);

	return matrixObj.invert();
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
Matrix4 CMainApplication::GetCurrentViewProjectionMatrix( vr::Hmd_Eye nEye )
{
	Matrix4 matMVP;
	if( nEye == vr::Eye_Left )
	{
		matMVP = m_mat4ProjectionLeft * m_mat4eyePosLeft * m_mat4HMDPose;
	}
	else if( nEye == vr::Eye_Right )
	{
		matMVP = m_mat4ProjectionRight * m_mat4eyePosRight *  m_mat4HMDPose;
	}

	return matMVP;
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void CMainApplication::UpdateHMDMatrixPose()
{
	if ( !m_pHMD )
		return;

	vr::VRCompositor()->WaitGetPoses(m_rTrackedDevicePose, vr::k_unMaxTrackedDeviceCount, NULL, 0 );

	m_iValidPoseCount = 0;
	m_strPoseClasses = "";
	for ( int nDevice = 0; nDevice < vr::k_unMaxTrackedDeviceCount; ++nDevice )
	{
		if ( m_rTrackedDevicePose[nDevice].bPoseIsValid )
		{
			m_iValidPoseCount++;
			m_rmat4DevicePose[nDevice] = ConvertSteamVRMatrixToMatrix4( m_rTrackedDevicePose[nDevice].mDeviceToAbsoluteTracking );
			if (m_rDevClassChar[nDevice]==0)
			{
				switch (m_pHMD->GetTrackedDeviceClass(nDevice))
				{
				case vr::TrackedDeviceClass_Controller:        m_rDevClassChar[nDevice] = 'C'; break;
				case vr::TrackedDeviceClass_HMD:               m_rDevClassChar[nDevice] = 'H'; break;
				case vr::TrackedDeviceClass_Invalid:           m_rDevClassChar[nDevice] = 'I'; break;
				case vr::TrackedDeviceClass_Other:             m_rDevClassChar[nDevice] = 'O'; break;
				case vr::TrackedDeviceClass_TrackingReference: m_rDevClassChar[nDevice] = 'T'; break;
				default:                                       m_rDevClassChar[nDevice] = '?'; break;
				}
			}
			m_strPoseClasses += m_rDevClassChar[nDevice];
		}
	}

	if ( m_rTrackedDevicePose[vr::k_unTrackedDeviceIndex_Hmd].bPoseIsValid )
	{
		m_mat4HMDPose = m_rmat4DevicePose[vr::k_unTrackedDeviceIndex_Hmd].invert();
	}
}


//-----------------------------------------------------------------------------
// Purpose: Finds a render model we've already loaded or loads a new one
//-----------------------------------------------------------------------------
CGLRenderModel *CMainApplication::FindOrLoadRenderModel( const char *pchRenderModelName )
{
	CGLRenderModel *pRenderModel = NULL;
	for( std::vector< CGLRenderModel * >::iterator i = m_vecRenderModels.begin(); i != m_vecRenderModels.end(); i++ )
	{
		if( !stricmp( (*i)->GetName().c_str(), pchRenderModelName ) )
		{
			pRenderModel = *i;
			break;
		}
	}

	// load the model if we didn't find one
	if( !pRenderModel )
	{
		vr::RenderModel_t *pModel;
		vr::EVRRenderModelError error;
		while ( 1 )
		{
			error = vr::VRRenderModels()->LoadRenderModel_Async( pchRenderModelName, &pModel );
			if ( error != vr::VRRenderModelError_Loading )
				break;

			ThreadSleep( 1 );
		}

		if ( error != vr::VRRenderModelError_None )
		{
			b3Printf( "Unable to load render model %s - %s\n", pchRenderModelName, vr::VRRenderModels()->GetRenderModelErrorNameFromEnum( error ) );
			return NULL; // move on to the next tracked device
		}

		vr::RenderModel_TextureMap_t *pTexture;
		while ( 1 )
		{
			error = vr::VRRenderModels()->LoadTexture_Async( pModel->diffuseTextureId, &pTexture );
			if ( error != vr::VRRenderModelError_Loading )
				break;

			ThreadSleep( 1 );
		}

		if ( error != vr::VRRenderModelError_None )
		{
			b3Printf( "Unable to load render texture id:%d for render model %s\n", pModel->diffuseTextureId, pchRenderModelName );
			vr::VRRenderModels()->FreeRenderModel( pModel );
			return NULL; // move on to the next tracked device
		}

		pRenderModel = new CGLRenderModel( pchRenderModelName );
		if ( !pRenderModel->BInit( *pModel, *pTexture ) )
		{
			b3Printf( "Unable to create GL model from render model %s\n", pchRenderModelName );
			delete pRenderModel;
			pRenderModel = NULL;
		}
		else
		{
			m_vecRenderModels.push_back( pRenderModel );
		}
		vr::VRRenderModels()->FreeRenderModel( pModel );
		vr::VRRenderModels()->FreeTexture( pTexture );
	}
	return pRenderModel;
}


//-----------------------------------------------------------------------------
// Purpose: Create/destroy GL a Render Model for a single tracked device
//-----------------------------------------------------------------------------
void CMainApplication::SetupRenderModelForTrackedDevice( vr::TrackedDeviceIndex_t unTrackedDeviceIndex )
{
	if( unTrackedDeviceIndex >= vr::k_unMaxTrackedDeviceCount )
		return;

	// try to find a model we've already set up
	std::string sRenderModelName = GetTrackedDeviceString( m_pHMD, unTrackedDeviceIndex, vr::Prop_RenderModelName_String );
	CGLRenderModel *pRenderModel = FindOrLoadRenderModel( sRenderModelName.c_str() );
	if( !pRenderModel )
	{
		std::string sTrackingSystemName = GetTrackedDeviceString( m_pHMD, unTrackedDeviceIndex, vr::Prop_TrackingSystemName_String );
		b3Printf( "Unable to load render model for tracked device %d (%s.%s)", unTrackedDeviceIndex, sTrackingSystemName.c_str(), sRenderModelName.c_str() );
	}
	else
	{
		m_rTrackedDeviceToRenderModel[ unTrackedDeviceIndex ] = pRenderModel;
		m_rbShowTrackedDevice[ unTrackedDeviceIndex ] = true;
	}
}


//-----------------------------------------------------------------------------
// Purpose: Create/destroy GL Render Models
//-----------------------------------------------------------------------------
void CMainApplication::SetupRenderModels()
{
	memset( m_rTrackedDeviceToRenderModel, 0, sizeof( m_rTrackedDeviceToRenderModel ) );

	if( !m_pHMD )
		return;

	for( uint32_t unTrackedDevice = vr::k_unTrackedDeviceIndex_Hmd + 1; unTrackedDevice < vr::k_unMaxTrackedDeviceCount; unTrackedDevice++ )
	{
		if( !m_pHMD->IsTrackedDeviceConnected( unTrackedDevice ) )
			continue;

		SetupRenderModelForTrackedDevice( unTrackedDevice );
	}

}


//-----------------------------------------------------------------------------
// Purpose: Converts a SteamVR matrix to our local matrix class
//-----------------------------------------------------------------------------
Matrix4 CMainApplication::ConvertSteamVRMatrixToMatrix4( const vr::HmdMatrix34_t &matPose )
{
	Matrix4 matrixObj(
		matPose.m[0][0], matPose.m[1][0], matPose.m[2][0], 0.0,
		matPose.m[0][1], matPose.m[1][1], matPose.m[2][1], 0.0,
		matPose.m[0][2], matPose.m[1][2], matPose.m[2][2], 0.0,
		matPose.m[0][3], matPose.m[1][3], matPose.m[2][3], 1.0f
		);
	return matrixObj;
}


//-----------------------------------------------------------------------------
// Purpose: Create/destroy GL Render Models
//-----------------------------------------------------------------------------
CGLRenderModel::CGLRenderModel( const std::string & sRenderModelName )
	: m_sModelName( sRenderModelName )
{
	m_glIndexBuffer = 0;
	m_glVertArray = 0;
	m_glVertBuffer = 0;
	m_glTexture = 0;
}


CGLRenderModel::~CGLRenderModel()
{
	Cleanup();
}


//-----------------------------------------------------------------------------
// Purpose: Allocates and populates the GL resources for a render model
//-----------------------------------------------------------------------------
bool CGLRenderModel::BInit( const vr::RenderModel_t & vrModel, const vr::RenderModel_TextureMap_t & vrDiffuseTexture )
{
	// create and bind a VAO to hold state for this model
	glGenVertexArrays( 1, &m_glVertArray );
	glBindVertexArray( m_glVertArray );

	// Populate a vertex buffer
	glGenBuffers( 1, &m_glVertBuffer );
	glBindBuffer( GL_ARRAY_BUFFER, m_glVertBuffer );
	glBufferData( GL_ARRAY_BUFFER, sizeof( vr::RenderModel_Vertex_t ) * vrModel.unVertexCount, vrModel.rVertexData, GL_STATIC_DRAW );

	// Identify the components in the vertex buffer
	glEnableVertexAttribArray( 0 );
	glVertexAttribPointer( 0, 3, GL_FLOAT, GL_FALSE, sizeof( vr::RenderModel_Vertex_t ), (void *)offsetof( vr::RenderModel_Vertex_t, vPosition ) );
	glEnableVertexAttribArray( 1 );
	glVertexAttribPointer( 1, 3, GL_FLOAT, GL_FALSE, sizeof( vr::RenderModel_Vertex_t ), (void *)offsetof( vr::RenderModel_Vertex_t, vNormal ) );
	glEnableVertexAttribArray( 2 );
	glVertexAttribPointer( 2, 2, GL_FLOAT, GL_FALSE, sizeof( vr::RenderModel_Vertex_t ), (void *)offsetof( vr::RenderModel_Vertex_t, rfTextureCoord ) );

	// Create and populate the index buffer
	glGenBuffers( 1, &m_glIndexBuffer );
	glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, m_glIndexBuffer );
	glBufferData( GL_ELEMENT_ARRAY_BUFFER, sizeof( uint16_t ) * vrModel.unTriangleCount * 3, vrModel.rIndexData, GL_STATIC_DRAW );

	glBindVertexArray( 0 );

	// create and populate the texture
	glGenTextures(1, &m_glTexture );
	glBindTexture( GL_TEXTURE_2D, m_glTexture );

	glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, vrDiffuseTexture.unWidth, vrDiffuseTexture.unHeight,
		0, GL_RGBA, GL_UNSIGNED_BYTE, vrDiffuseTexture.rubTextureMapData );

	// If this renders black ask McJohn what's wrong.
	glGenerateMipmap(GL_TEXTURE_2D);

	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR );

	GLfloat fLargest;
	glGetFloatv( GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &fLargest );
	glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, fLargest );

	glBindTexture( GL_TEXTURE_2D, 0 );

	m_unVertexCount = vrModel.unTriangleCount * 3;

	return true;
}


//-----------------------------------------------------------------------------
// Purpose: Frees the GL resources for a render model
//-----------------------------------------------------------------------------
void CGLRenderModel::Cleanup()
{
	if( m_glVertBuffer )
	{
		glDeleteBuffers(1, &m_glIndexBuffer);
		glDeleteVertexArrays( 1, &m_glVertArray );
		glDeleteBuffers(1, &m_glVertBuffer);
		m_glIndexBuffer = 0;
		m_glVertArray = 0;
		m_glVertBuffer = 0;
	}
}


//-----------------------------------------------------------------------------
// Purpose: Draws the render model
//-----------------------------------------------------------------------------
void CGLRenderModel::Draw()
{
	glBindVertexArray( m_glVertArray );

	glActiveTexture( GL_TEXTURE0 );
	glBindTexture( GL_TEXTURE_2D, m_glTexture );

	glDrawElements( GL_TRIANGLES, m_unVertexCount, GL_UNSIGNED_SHORT, 0 );

	glBindVertexArray( 0 );
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
int main(int argc, char *argv[])
{
	CMainApplication *pMainApplication = new CMainApplication( argc, argv );

	if (!pMainApplication->BInit())
	{
		pMainApplication->Shutdown();
		return 1;
	}

	pMainApplication->RunMainLoop();

	pMainApplication->Shutdown();

	return 0;
}
#endif //BT_ENABLE_VR