//========= Copyright Valve Corporation ============//

#include "hmd_opencv_sandbox.h"
#include "chew.h"

CMainApplication * APP;

//---------------------------------------------------------------------------------------------------------------------
// Purpose: Returns true if the action is active and its state is true
//---------------------------------------------------------------------------------------------------------------------
bool GetDigitalActionState(vr::VRActionHandle_t action, vr::VRInputValueHandle_t *pDevicePath = nullptr )
{
	vr::InputDigitalActionData_t actionData;
	vr::VRInput()->GetDigitalActionData(action, &actionData, sizeof(actionData), vr::k_ulInvalidInputValueHandle );
	if (pDevicePath)
	{
		*pDevicePath = vr::k_ulInvalidInputValueHandle;
		if (actionData.bActive)
		{
			vr::InputOriginInfo_t originInfo;
			if (vr::VRInputError_None == vr::VRInput()->GetOriginTrackedDeviceInfo(actionData.activeOrigin, &originInfo, sizeof(originInfo)))
			{
				*pDevicePath = originInfo.devicePath;
			}
		}
	}
	return actionData.bActive && actionData.bState;
}

//---------------------------------------------------------------------------------------------------------------------
// Purpose: Returns true if the action is active and had a falling edge
//---------------------------------------------------------------------------------------------------------------------
bool GetDigitalActionFallingEdge( vr::VRActionHandle_t action, vr::VRInputValueHandle_t *pDevicePath = nullptr )
{
	vr::InputDigitalActionData_t actionData;
	vr::VRInput()->GetDigitalActionData( action, &actionData, sizeof( actionData ), vr::k_ulInvalidInputValueHandle );
	if ( pDevicePath )
	{
		*pDevicePath = vr::k_ulInvalidInputValueHandle;
		if ( actionData.bActive )
		{
			vr::InputOriginInfo_t originInfo;
			if ( vr::VRInputError_None == vr::VRInput()->GetOriginTrackedDeviceInfo( actionData.activeOrigin, &originInfo, sizeof( originInfo ) ) )
			{
				*pDevicePath = originInfo.devicePath;
			}
		}
	}
	return actionData.bActive && actionData.bChanged && !actionData.bState;
}


//-----------------------------------------------------------------------------
// Purpose: This is called by SDL in PromptAssertion.
//-----------------------------------------------------------------------------
static FILE _iob[] = { *stdin, *stdout, *stderr }; 
extern "C" FILE * __cdecl __iob_func( void ) { return _iob; }

//-----------------------------------------------------------------------------
// Purpose: Constructor
//-----------------------------------------------------------------------------
CMainApplication::CMainApplication( int argc, char *argv[] )
	: m_nCompanionWindowWidth( 2048 )
	, m_nCompanionWindowHeight( 1024 )
	, m_shdCompanionWindowProgram( CONTENT_FOLDER"/companion" )
	, m_pIVRSystem( NULL )
	, m_bDebugOpenGL( false )
	, m_bVerbose( false )
	, m_bPerf( false )
	, m_bVblank( false )
	, m_strPoseClasses( "" )
	, m_CameraApp( this )
	, bQuit( false )
	, m_geoCompanion( "CompanionGeo" )
	, m_shdRenderModel( CONTENT_FOLDER"/rendermodel" )
{
	APP = this;

	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;
		}
	}
	// other initialization tasks are done in BInit
	memset(m_rDevClassChar, 0, sizeof(m_rDevClassChar));
};


//-----------------------------------------------------------------------------
// Purpose: Destructor
//-----------------------------------------------------------------------------
CMainApplication::~CMainApplication()
{
	// work is done in Shutdown
	dprintf( 0, "Shutdown" );

	if ( m_pCompanionWindow )
	{
		SDL_DestroyWindow( m_pCompanionWindow );
		m_pCompanionWindow = NULL;
	}
}


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

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


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
bool CMainApplication::BInit()
{
	if ( SDL_Init( SDL_INIT_VIDEO | SDL_INIT_TIMER ) < 0 )
	{
		printf( "%s - SDL could not initialize! SDL Error: %s\n", __FUNCTION__, SDL_GetError() );
		return false;
	}

	vr::EVRInitError eError = vr::VRInitError_None;
	m_pIVRSystem = vr::VR_Init( &eError, vr::VRApplication_Scene );

	if ( eError != vr::VRInitError_None )
	{
		m_pIVRSystem = NULL;
		printf( "Unable to init VR runtime: %s", vr::VR_GetVRInitErrorAsEnglishDescription( eError ) );
		return false;
	}


	int nWindowPosX = 700;
	int nWindowPosY = 100;
	Uint32 unWindowFlags = SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN;

	SDL_GL_SetAttribute( SDL_GL_CONTEXT_MAJOR_VERSION, 4 );
	SDL_GL_SetAttribute( SDL_GL_CONTEXT_MINOR_VERSION, 1 );
	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_pCompanionWindow = SDL_CreateWindow( "hmd_opencv_sandbox", nWindowPosX, nWindowPosY, m_nCompanionWindowWidth, m_nCompanionWindowHeight, unWindowFlags );
	if ( m_pCompanionWindow == NULL )
	{
		printf( "%s - Window could not be created! SDL Error: %s\n", __FUNCTION__, SDL_GetError() );
		return false;
	}

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


	chewInit();

	m_strDisplay = GetTrackedDeviceString( vr::k_unTrackedDeviceIndex_Hmd, vr::Prop_SerialNumber_String );
	std::string strWindowTitle = "hmd_opencv_sandbox - " + m_strDisplay;
	SDL_SetWindowTitle( m_pCompanionWindow, strWindowTitle.c_str() );

 	m_fNearClip = 0.1f;
 	m_fFarClip = 60.0f;

	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;
	}

	std::string basepath;
	{
		char curdir[MAX_PATH];
		GetCurrentDirectoryA( MAX_PATH, curdir );
		basepath = curdir;
	}

	//If we want to be relative to the executable instead of the working folder we can do this.
	//std::string basepath = Path_StripFilename( Path_GetExecutablePath() );
	vr::VRInput()->SetActionManifestPath( Path_MakeAbsolute( CONTENT_FOLDER"/hmd_opencv_sandbox_actions.json", basepath ).c_str() );

	vr::VRInput()->GetActionSetHandle( "/actions/demo", &m_actionsetDemo );

	vr::VRInput()->GetActionHandle( "/actions/demo/in/advance_demo", &m_actionAdvanceDemo );
	vr::VRInput()->GetActionHandle( "/actions/demo/in/AnalogInput", &m_actionAnalongInput );
	vr::VRInput()->GetInputSourceHandle( "/user/hand/left", &m_rHand[Left].m_source );
	vr::VRInput()->GetActionHandle( "/actions/demo/in/Hand_Left", &m_rHand[Left].m_actionPose );
	vr::VRInput()->GetInputSourceHandle( "/user/hand/right", &m_rHand[Right].m_source );
	vr::VRInput()->GetActionHandle( "/actions/demo/in/Hand_Right", &m_rHand[Right].m_actionPose );

	m_CameraApp.BInit();

	return true;
}


//-----------------------------------------------------------------------------
// Purpose: Outputs the string in message to debugging output.
//          All other parameters are ignored.
//          Does not return any meaningful value or reference.
//-----------------------------------------------------------------------------
void APIENTRY DebugCallback(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const char* message, const void* userParam)
{
	dprintf( 0, "GL Error: %s\n", message );
}


//-----------------------------------------------------------------------------
// Purpose: Initialize OpenGL. Returns true if OpenGL has been successfully
//          initialized, false if shaders could not be created.
//          If failure occurred in a module other than shaders, the function
//          may return true or throw an error. 
//-----------------------------------------------------------------------------
bool CMainApplication::BInitGL()
{
	if( m_bDebugOpenGL )
	{
		glDebugMessageCallback( (GLDEBUGPROC)DebugCallback, nullptr);
		glDebugMessageControl( GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, nullptr, GL_TRUE );
		glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
	}

	SetupStereoRenderTargets();
	SetupCompanionWindow();

	return true;
}


//-----------------------------------------------------------------------------
// Purpose: Initialize Compositor. Returns true if the compositor was
//          successfully initialized, false otherwise.
//-----------------------------------------------------------------------------
bool CMainApplication::BInitCompositor()
{
	if ( !vr::VRCompositor() )
	{
		printf( "Compositor initialization failed. See log file for details\n" );
		return false;
	}
	return true;
}


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

	m_CameraApp.Shutdown();

	for( std::vector< GeometryObject * >::iterator i = m_vecRenderModels.begin(); i != m_vecRenderModels.end(); i++ )
	{
		delete (*i);
	}
	m_vecRenderModels.clear();
	
	if( m_bDebugOpenGL )
	{
		glDebugMessageControl( GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, nullptr, GL_FALSE );
		glDebugMessageCallback(nullptr, nullptr);
	}

	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 );

	dprintf( 0, "Shutdown complete. Exiting\n" );
	exit( 0 );
}

//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
bool CMainApplication::HandleInput()
{
	SDL_Event sdlEvent;
	bool bRet = false;

	while ( SDL_PollEvent( &sdlEvent ) != 0 )
	{
		if ( sdlEvent.type == SDL_QUIT )
		{
			bRet = true;
		}
		else if ( sdlEvent.type == SDL_KEYDOWN )
		{
			if ( sdlEvent.key.keysym.sym == SDLK_ESCAPE )
			{
				bRet = true;
			}
			else
			{
				APP->m_CameraApp.KeyDown( sdlEvent.key.keysym.sym );
			}
		}
	}

	// Process SteamVR events
	vr::VREvent_t event;
	while( m_pIVRSystem->PollNextEvent( &event, sizeof( event ) ) )
	{
		ProcessVREvent( event );
	}

	// Process SteamVR action state
	// UpdateActionState is called each frame to update the state of the actions themselves. The application
	// controls which action sets are active with the provided array of VRActiveActionSet_t structs.
	vr::VRActiveActionSet_t actionSet = { 0 };
	actionSet.ulActionSet = m_actionsetDemo;
	vr::VRInput()->UpdateActionState( &actionSet, sizeof(actionSet), 1 );



	vr::VRInputValueHandle_t ulAdvanceDemo;
	if ( GetDigitalActionFallingEdge( m_actionAdvanceDemo, &ulAdvanceDemo ) )
	{
		if ( ulAdvanceDemo == m_rHand[Left].m_source )
		{
			m_CameraApp.AdvanceSettings( -1 );
		}
		if ( ulAdvanceDemo == m_rHand[Right].m_source )
		{
			m_CameraApp.AdvanceSettings( 1 );
		}
	}

#if 0
	vr::VRInputValueHandle_t ulAdvanceDemo;
	if ( GetDigitalActionState( m_actionAdvanceDemo, &ulAdvanceDemo ) )
	{
		if ( ulAdvanceDemo == m_rHand[Left].m_source )
		{
			m_CameraApp.AdvanceSettings( -1 );
		}
		if ( ulAdvanceDemo == m_rHand[Right].m_source )
		{
			m_CameraApp.AdvanceSettings( 1 );
		}
	}
#endif


	vr::InputAnalogActionData_t analogData;
	if ( vr::VRInput()->GetAnalogActionData( m_actionAnalongInput, &analogData, sizeof( analogData ), vr::k_ulInvalidInputValueHandle ) == vr::VRInputError_None && analogData.bActive )
	{
		m_vAnalogValue[0] = analogData.x;
		m_vAnalogValue[1] = analogData.y;
	}

	m_rHand[Left].m_bShowController = true;
	m_rHand[Right].m_bShowController = true;

	for ( EHand eHand = Left; eHand <= Right; ((int&)eHand)++ )
	{
		vr::InputPoseActionData_t poseData;
		vr::EVRInputError e = vr::VRInput()->GetPoseActionDataRelativeToNow( m_rHand[eHand].m_actionPose, vr::TrackingUniverseStanding, 0, &poseData, sizeof( poseData ), vr::k_ulInvalidInputValueHandle );
		if ( e != vr::VRInputError_None || !poseData.bActive || !poseData.pose.bPoseIsValid )
		{
			m_rHand[eHand].m_bShowController = false;
		}
		else
		{
			m_rHand[eHand].m_rmat4Pose = ConvertSteamVRMatrixToMatrix4( poseData.pose.mDeviceToAbsoluteTracking );

			vr::InputOriginInfo_t originInfo;
			if ( vr::VRInput()->GetOriginTrackedDeviceInfo( poseData.activeOrigin, &originInfo, sizeof( originInfo ) ) == vr::VRInputError_None
				&& originInfo.trackedDeviceIndex != vr::k_unTrackedDeviceIndexInvalid )
			{
				std::string sRenderModelName = GetTrackedDeviceString( originInfo.trackedDeviceIndex, vr::Prop_RenderModelName_String );
				if ( sRenderModelName != m_rHand[eHand].m_sRenderModelName )
				{
					dprintf( 0, "Found controller.  Loading rendermodel %s\n", sRenderModelName.c_str() );
					m_rHand[eHand].m_pRenderModel = FindOrLoadRenderModel( sRenderModelName.c_str() );
					m_rHand[eHand].m_sRenderModelName = sRenderModelName;
				}
			}
		}
	}
	return bRet;
}

//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void CMainApplication::RunMainLoop()
{
	SDL_StartTextInput();
	SDL_ShowCursor( SDL_DISABLE );

	while ( !bQuit )
	{
		bQuit = HandleInput();
		RenderFrame();
	}

	dprintf( 0, "Main loop exited.\n" );
	SDL_StopTextInput();
}


//-----------------------------------------------------------------------------
// Purpose: Processes a single VR event
//-----------------------------------------------------------------------------
void CMainApplication::ProcessVREvent( const vr::VREvent_t & event )
{
	switch( event.eventType )
	{
	case vr::VREvent_TrackedDeviceDeactivated:
		{
			dprintf( 0, "Device %u detached.\n", event.trackedDeviceIndex );
		}
		break;
	case vr::VREvent_TrackedDeviceUpdated:
		{
			dprintf( 0, "Device %u updated.\n", event.trackedDeviceIndex );
		}
		break;
	}
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void CMainApplication::RenderFrame()
{
	std::stringstream errors;
	if ( m_shdCompanionWindowProgram.CheckShader( errors ) < 0 || m_shdRenderModel.CheckShader( errors ) < 0 )
	{
		std::cout << errors.str() << std::endl;
	}
	SetupCameras();

	if ( m_pIVRSystem )
	{
		m_trmErrors.Prerender();
		m_trmProfile.Prerender();
		m_CameraApp.Prerender();
		//Do rendering
		RenderStereoTargets();
		RenderCompanionWindow();

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

	//$ 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
	{
		SDL_GL_SwapWindow( m_pCompanionWindow );
	}

	// 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.
		glColorMask( TRUE, TRUE, TRUE, TRUE );//This ensures that only alpha will be effected
		glClearColor( 0, 0, 0, 0 );
		glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
	}

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

	UpdateHMDMatrixPose();
}

//-----------------------------------------------------------------------------
// 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: Creates a frame buffer. Returns true if the buffer was set up.
//          Returns false if the setup failed.
//-----------------------------------------------------------------------------
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_pIVRSystem )
		return false;

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

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


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void CMainApplication::SetupCompanionWindow()
{
	if ( !m_pIVRSystem )
		return;

	m_geoCompanion.MakeUnitSquare( 0 );
	m_geoCompanion.Check();
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void CMainApplication::RenderStereoTargets()
{
	glClearColor( 0.0f, 0.0f, 0.0f, 0.0f );
	glEnable( GL_MULTISAMPLE );

	// Left Eye
	glBindFramebuffer( GL_FRAMEBUFFER, leftEyeDesc.m_nRenderFramebufferId );
 	glViewport(0, 0, m_nRenderWidth, m_nRenderHeight );
 	RenderScene( vr::Eye_Left );
 	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
	glBindFramebuffer( GL_FRAMEBUFFER, rightEyeDesc.m_nRenderFramebufferId );
 	glViewport(0, 0, m_nRenderWidth, m_nRenderHeight );
 	RenderScene( vr::Eye_Right );
 	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: Renders a scene with respect to nEye.
//-----------------------------------------------------------------------------
void CMainApplication::RenderScene( vr::Hmd_Eye nEye )
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glEnable(GL_DEPTH_TEST);

	gCurrentViewProjection = GetCurrentViewProjectionMatrix( nEye );
	
	//Render any controllers
	for ( EHand eHand = Left; eHand <= Right; ((int&)eHand)++ )
	{
		if ( !m_rHand[eHand].m_bShowController || !m_rHand[eHand].m_pRenderModel )
			continue;

		const Matrix4 & matDeviceToTracking = m_rHand[eHand].m_rmat4Pose;
		Matrix4 matMVP = gCurrentViewProjection * matDeviceToTracking;

		m_shdRenderModel.Use();
		glUniformMatrix4fv( 0, 1, GL_FALSE, matMVP.get() );
		m_rHand[eHand].m_pRenderModel->Render();

		if ( eHand == Left )
		{
			Matrix4 premat;
			premat.identity();
			premat.translate( 1.2f, 0.5f, 0.0 );
			premat.scale( 0.2f, 0.2f, 1.0 );
			premat.rotateZ( 110 ); //How much to rotate the screen, itself.
			premat.rotateX( 120 );
			premat.rotateZ( 60 ); //How much to swing around back.

			m_trmErrors.SetXFormPre( premat );
			m_trmErrors.SetXForm( matDeviceToTracking );
			glEnable( GL_CULL_FACE );
			glCullFace( GL_FRONT );
			m_trmErrors.Render();
			glDisable( GL_CULL_FACE );
		}
		if ( eHand == Right )
		{
			Matrix4 premat;
			premat.identity();
			premat.rotateZ( 180 );
			premat.translate( 1.2f, -0.5f, 0.0 );
			premat.scale( 0.2f, 0.2f, 1.0 );
			premat.rotateZ( 180 - 110 );
			premat.rotateX( 120 );
			premat.rotateZ( 110 + 180 );

			m_trmProfile.SetXFormPre( premat );
			m_trmProfile.SetXForm( matDeviceToTracking );
			glEnable( GL_CULL_FACE );
			glCullFace( GL_FRONT );
			m_trmProfile.Render();
			glDisable( GL_CULL_FACE );
		}

	}

	//Render the rest of the scene.
	m_CameraApp.RenderScene( nEye );
}


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void CMainApplication::RenderCompanionWindow()
{
	glDisable(GL_DEPTH_TEST);
	glViewport( 0, 0, m_nCompanionWindowWidth/2, m_nCompanionWindowHeight );

	m_shdCompanionWindowProgram.Use();

	// render left eye (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 );
	m_geoCompanion.Render();

	glUseProgram( 0 );

	m_CameraApp.CompanionRender();
}


//-----------------------------------------------------------------------------
// Purpose: Gets a Matrix Projection Eye with respect to nEye.
//-----------------------------------------------------------------------------
Matrix4 CMainApplication::GetHMDMatrixProjectionEye( vr::Hmd_Eye nEye )
{
	if ( !m_pIVRSystem )
		return Matrix4();

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

	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: Gets an HMDMatrixPoseEye with respect to nEye.
//-----------------------------------------------------------------------------
Matrix4 CMainApplication::GetHMDMatrixPoseEye( vr::Hmd_Eye nEye )
{
	if ( !m_pIVRSystem )
		return Matrix4();

	vr::HmdMatrix34_t matEyeRight = m_pIVRSystem->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: Gets a Current View Projection Matrix with respect to nEye,
//          which may be an Eye_Left or an Eye_Right.
//-----------------------------------------------------------------------------
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_pIVRSystem )
		return;

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

	m_strPoseClasses = "";
	for ( int nDevice = 0; nDevice < vr::k_unMaxTrackedDeviceCount; ++nDevice )
	{
		if ( m_rTrackedDevicePose[nDevice].bPoseIsValid )
		{
			m_rmat4DevicePose[nDevice] = ConvertSteamVRMatrixToMatrix4( m_rTrackedDevicePose[nDevice].mDeviceToAbsoluteTracking );
			if (m_rDevClassChar[nDevice]==0)
			{
				switch ( m_pIVRSystem->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_GenericTracker:    m_rDevClassChar[nDevice] = 'G'; 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];
		m_mat4HMDPose.invert();
	}
}


//-----------------------------------------------------------------------------
// Purpose: Finds a render model we've already loaded or loads a new one
//-----------------------------------------------------------------------------
GeometryObject *CMainApplication::FindOrLoadRenderModel( const char *pchRenderModelName )
{
	GeometryObject *pRenderModel = NULL;
	for( std::vector< GeometryObject * >::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;

			OGUSleep( 1000 );
		}

		if ( error != vr::VRRenderModelError_None )
		{
			dprintf( 0,"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;

			OGUSleep( 1000 );
		}

		if ( error != vr::VRRenderModelError_None )
		{
			dprintf( 0, "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 GeometryObject( pchRenderModelName );
		if( pRenderModel->CreateFromRenderModel( pModel ) || pRenderModel->ApplyTextureRM( pTexture ) )
		{
			dprintf( 0, "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;
}

#undef main

extern "C" { int main( int argc, char * argv[] ); }

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

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

	pMainApplication->RunMainLoop();

	dprintf( 0, "Shutting down.\n" );
	pMainApplication->Shutdown();
}