#ifdef BT_ENABLE_VR
#ifdef BT_USE_CUSTOM_PROFILER
#endif

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

#include "../OpenGLWindow/SimpleOpenGL3App.h"
#include "../OpenGLWindow/OpenGLInclude.h"
#include "Bullet3Common/b3Quaternion.h"
#include "Bullet3Common/b3Transform.h"
#include "Bullet3Common/b3CommandLineArgs.h"

#include "../Utils/b3Clock.h"
#include "../Utils/ChromeTraceUtil.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"

#ifdef __APPLE__
#define GL_DO_NOT_WARN_IF_MULTI_GL_VERSION_HEADERS_INCLUDED
#import <Cocoa/Cocoa.h>
#endif  //__APPLE__

#include "LinearMath/btIDebugDraw.h"
int gSharedMemoryKey = -1;
static int gDebugDrawFlags = 0;
static bool gDisplayDistortion = false;
static bool gDisableDesktopGL = false;

static int maxNumObjectCapacity = 128 * 1024;
static int maxShapeCapacityInBytes = 128 * 1024 * 1024;

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

#include <openvr.h>
#include "strtools.h"
#include "compat.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
#ifdef __linux__
#define APIENTRY
#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);

	SimpleOpenGL3App *getApp() { return m_app; }

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;
	b3Clock m_clock;

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;
}

b3KeyboardCallback prevKeyboardCallback = 0;

void MyKeyboardCallback(int key, int state)
{
	if (key == 'p')
	{
		if (state)
		{
			b3ChromeUtilsStartTimings();
		}
		else
		{
			b3ChromeUtilsStopTimingsAndWriteJsonFile("timings");
		}
	}
	if (sExample)
	{
		sExample->keyboardCallback(key, state);
	}

	if (prevKeyboardCallback)
		prevKeyboardCallback(key, state);
}

#include "../SharedMemory/SharedMemoryPublic.h"
extern bool useShadowMap;
static bool gEnableVRRenderControllers = true;
static bool gEnableVRRendering = true;
static int gUpAxis = 2;

void VRPhysicsServerVisualizerFlagCallback(int flag, bool enable)
{
	if (flag == COV_ENABLE_Y_AXIS_UP)
	{
		//either Y = up or Z
		gUpAxis = enable ? 1 : 2;
	}

	if (flag == COV_ENABLE_SHADOWS)
	{
		useShadowMap = enable;
	}
	if (flag == COV_ENABLE_GUI)
	{
		//there is no regular GUI here, but disable the
	}
	if (flag == COV_ENABLE_VR_RENDER_CONTROLLERS)
	{
		gEnableVRRenderControllers = enable;
	}
	if (flag == COV_ENABLE_RENDERING)
	{
		gEnableVRRendering = enable;
	}

	if (flag == COV_ENABLE_WIREFRAME)
	{
		if (enable)
		{
			glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
			//gDebugDrawFlags |= btIDebugDraw::DBG_DrawWireframe;
		}
		else
		{
			glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
			//gDebugDrawFlags &= ~btIDebugDraw::DBG_DrawWireframe;
		}
	}
}

//-----------------------------------------------------------------------------
// 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, maxNumObjectCapacity, maxShapeCapacityInBytes);

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

	//sGuiPtr = new DummyGUIHelper;

	prevKeyboardCallback = m_app->m_window->getKeyboardCallback();
	m_app->m_window->setKeyboardCallback(MyKeyboardCallback);

	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;
	}



	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);
		}
	}

	if (sExample)
	{
		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, sizeof(vr::VRControllerState_t)))
		{
			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]};

			//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_HMD)
			{
				Matrix4 rotYtoZ = rotYtoZ.identity();
				//some Bullet apps (especially robotics related) require Z as up-axis)
				if (m_app->getUpAxis() == 2)
				{
					rotYtoZ.rotateX(-90);
				}
				Matrix4 viewMatCenter = m_mat4HMDPose * rotYtoZ;
				const float *mat = viewMatCenter.invertAffine().get();
				pos[0] = mat[12];
				pos[1] = mat[13];
				pos[2] = mat[14];

				b3Matrix3x3 bmat;
				for (int i = 0; i < 3; i++)
				{
					for (int j = 0; j < 3; j++)
					{
						bmat[i][j] = mat[i + 4 * j];
					}
				}
				b3Quaternion orn2;
				bmat.getRotation(orn2);
				orn[0] = orn2[0];
				orn[1] = orn2[1];
				orn[2] = orn2[2];
				orn[3] = orn2[3];
				sExample->vrHMDMoveCallback(unDevice, pos, orn);
			}

			if (m_pHMD->GetTrackedDeviceClass(unDevice) == vr::TrackedDeviceClass_GenericTracker)
			{
				sExample->vrGenericTrackerMoveCallback(unDevice, pos, orn);
			}

			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);

					btAssert(vr::k_unControllerStateAxisCount >= 5);
					float allAxis[10];  //store x,y times 5 controllers
					int index = 0;
					for (int i = 0; i < 5; i++)
					{
						allAxis[index++] = state.rAxis[i].x;
						allAxis[index++] = state.rAxis[i].y;
					}
					bool isTrigger = (state.ulButtonPressed & trigger) != 0;
					if (isTrigger)
					{
						//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);
							sExample->vrControllerButtonCallback(unDevice, button, 1, pos, orn);
						}
						else
						{
							//							printf("Device MOVED: %d\n", unDevice);
							sExample->vrControllerMoveCallback(unDevice, pos, orn, state.rAxis[1].x, allAxis);
						}
					}
					else
					{
						if (m_pHMD->GetTrackedDeviceClass(unDevice) == vr::TrackedDeviceClass_Controller)
						{
							//							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;
								}

								sExample->vrControllerButtonCallback(unDevice, button, 0, pos, orn);
							}
							else
							{
								sExample->vrControllerMoveCallback(unDevice, pos, orn, state.rAxis[1].x, allAxis);
							}
						}
					}
				}
			}

			//			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())
	{
		this->m_app->setUpAxis(gUpAxis);
		b3ChromeUtilsEnableProfiling();
		if (gEnableVRRendering)
		{
			B3_PROFILE("main");

			bQuit = HandleInput();

			RenderFrame();
		}
		else
		{
			b3Clock::usleep(0);
			sExample->updateGraphics();
		}
	}
}

//-----------------------------------------------------------------------------
// 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)
	{
		{
			B3_PROFILE("DrawControllers");
			DrawControllers();
		}
		RenderStereoTargets();

		if (!gDisableDesktopGL)
		{
			if (gDisplayDistortion)
			{
				B3_PROFILE("RenderDistortion");
				RenderDistortion();
			}
			else
			{
				//todo: should use framebuffer_multisample_blit_scaled
				//See https://twitter.com/id_aa_carmack/status/268488838425481217?lang=en
				glBindFramebuffer(GL_FRAMEBUFFER, 0);
				glDisable(GL_MULTISAMPLE);
				glBindFramebuffer(GL_READ_FRAMEBUFFER, rightEyeDesc.m_nRenderFramebufferId);
				glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);

				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);
			}
		}

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

	if (m_bVblank && m_bGlFinishHack)
	{
		B3_PROFILE("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
	{
		B3_PROFILE("m_app->swapBuffer");
		if (!gDisableDesktopGL)
		{
			m_app->swapBuffer();
		}
		//SDL_GL_SwapWindow( m_pWindow );
	}

	// Clear
	{
		B3_PROFILE("glClearColor");
		// 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)
	{
		B3_PROFILE("glFlushglFinish");

		glFlush();
		glFinish();
	}

	// Spew out the controller and pose count whenever they change.
	if (m_iTrackedControllerCount != m_iTrackedControllerCount_Last || m_iValidPoseCount != m_iValidPoseCount_Last)
	{
		B3_PROFILE("debug pose");

		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);
	}

	{
		B3_PROFILE("UpdateHMDMatrixPose");
		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, &fLargest);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY, 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
//-----------------------------------------------------------------------------
extern int gGraspingController;

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;
			bool result = m_pHMD->ComputeDistortion(vr::Eye_Left, u, v, &dc0);
			btAssert(result);
			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;
			bool result = m_pHMD->ComputeDistortion(vr::Eye_Right, u, v, &dc0);
			btAssert(result);
			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()
{
	B3_PROFILE("CMainApplication::RenderStereoTargets");

	btScalar dtSec = btScalar(m_clock.getTimeInSeconds());
	dtSec = btMin(dtSec, btScalar(0.1));
	sExample->stepSimulation(dtSec);
	m_clock.reset();

	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());
		m_app->m_instancingRenderer->getActiveCamera()->setVRCamera(viewMatLeft.get(), m_mat4ProjectionLeft.get());
	}

	glBindFramebuffer(GL_FRAMEBUFFER, leftEyeDesc.m_nRenderFramebufferId);

	m_app->m_window->startRendering();
	glViewport(0, 0, m_nRenderWidth, m_nRenderHeight);

	RenderScene(vr::Eye_Left);

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

	if (gDebugDrawFlags)
	{
		sExample->physicsDebugDraw(gDebugDrawFlags);
	}
	//else
	{
		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());
		m_app->m_instancingRenderer->getActiveCamera()->setVRCamera(viewMatRight.get(), m_mat4ProjectionRight.get());
	}

	glBindFramebuffer(GL_FRAMEBUFFER, rightEyeDesc.m_nRenderFramebufferId);

	m_app->m_window->startRendering();
	glViewport(0, 0, m_nRenderWidth, m_nRenderHeight);

	RenderScene(vr::Eye_Right);

	m_app->m_instancingRenderer->setRenderFrameBuffer((unsigned int)rightEyeDesc.m_nRenderFramebufferId);
	//m_app->m_renderer->renderScene();

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

	//m_app->drawGrid(gridUp);

	m_app->m_instancingRenderer->setRenderFrameBuffer(0);
	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)
{
	B3_PROFILE("RenderScene");

	//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 (gEnableVRRenderControllers)
	{
		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);

	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;
	{
		B3_PROFILE("WaitGetPoses");
		vr::VRCompositor()->WaitGetPoses(m_rTrackedDevicePose, vr::k_unMaxTrackedDeviceCount, NULL, 0);
	}

	m_iValidPoseCount = 0;
	m_strPoseClasses = "";
	{
		B3_PROFILE("for loop");

		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_TrackingReference:
							m_rDevClassChar[nDevice] = 'T';
							break;
						case vr::TrackedDeviceClass_GenericTracker:
							m_rDevClassChar[nDevice] = 'G';
							break;
						default:
							m_rDevClassChar[nDevice] = '?';
							break;
					}
				}
				m_strPoseClasses += m_rDevClassChar[nDevice];
			}
		}
	}
	{
		B3_PROFILE("m_mat4HMDPose invert");

		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, &fLargest);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY, 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[])
{
	b3CommandLineArgs args(argc, argv);
	if (args.CheckCmdLineFlag("disable_desktop_gl"))
	{
		gDisableDesktopGL = true;
	}
	if (args.CheckCmdLineFlag("tracing"))
	{
		b3ChromeUtilsStartTimings();
		b3ChromeUtilsEnableProfiling();
	}

	args.GetCmdLineArgument("max_num_object_capacity", maxNumObjectCapacity);
	args.GetCmdLineArgument("max_shape_capacity_in_bytes", maxShapeCapacityInBytes);
	args.GetCmdLineArgument("shared_memory_key", gSharedMemoryKey);

#ifdef BT_USE_CUSTOM_PROFILER
	b3SetCustomEnterProfileZoneFunc(dcEnter);
	b3SetCustomLeaveProfileZoneFunc(dcLeave);
#endif

	CMainApplication *pMainApplication = new CMainApplication(argc, argv);

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

	if (sExample)
	{
		//until we have a proper VR gui, always assume we want the hard-coded default robot assets
		char *newargv[2];
		char *t0 = (char *)"--robotassets";
		newargv[0] = t0;
		newargv[1] = t0;
		sExample->processCommandLineArgs(2, newargv);
		sExample->processCommandLineArgs(argc, argv);
	}

	char *gVideoFileName = 0;
	args.GetCmdLineArgument("mp4", gVideoFileName);
	if (gVideoFileName)
		pMainApplication->getApp()->dumpFramesToVideo(gVideoFileName);

#ifndef B3_USE_GLFW
#ifdef _WIN32
	//request disable VSYNC
	typedef bool(APIENTRY * PFNWGLSWAPINTERVALFARPROC)(int);
	PFNWGLSWAPINTERVALFARPROC wglSwapIntervalEXT = 0;
	wglSwapIntervalEXT =
		(PFNWGLSWAPINTERVALFARPROC)wglGetProcAddress("wglSwapIntervalEXT");
	if (wglSwapIntervalEXT)
		wglSwapIntervalEXT(0);
#endif
#endif
#ifdef __APPLE__
	GLint sync = 0;
	CGLContextObj ctx = CGLGetCurrentContext();
	CGLSetParameter(ctx, kCGLCPSwapInterval, &sync);
#endif

	pMainApplication->RunMainLoop();

	pMainApplication->Shutdown();

	if (args.CheckCmdLineFlag("tracing"))
	{
		b3ChromeUtilsStopTimingsAndWriteJsonFile("timings");
	}

	return 0;
}
#endif  //BT_ENABLE_VR