（五）代码b.1和代码c.0：VR眼镜显示全景图片和全景视频

b.1:

主要是增加了SetupRC这个初始化函数，读取天空盒六面图片。

#include 
#include 
#include 
#if defined( OSX )
#include 
#include 
#include 
// Apple's version of glut.h #undef's APIENTRY, redefine it
#define APIENTRY
#else
#include 
#endif
#include 
#include 
#include 

#include 

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

#if defined(POSIX)
#include "unistd.h"
#endif

#ifndef _WIN32
#define APIENTRY
#endif

#ifndef _countof
#define _countof(x) (sizeof(x)/sizeof((x)[0]))
#endif

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

#include 	// OpenGL toolkit
#include 
#include 
#include 
#include 
#include 

#include 
#include 

#include 
#include 
#include 
#include 
using namespace cv;

GLFrame             viewFrame;
GLFrustum           viewFrustum;
GLTriangleBatch     sphereBatch;
GLBatch             cubeBatch;
GLMatrixStack       modelViewMatrix;
GLMatrixStack       projectionMatrix;
GLGeometryTransform transformPipeline;
GLuint              cubeTexture;
GLint               reflectionShader;
GLint               skyBoxShader;

GLint               locMVPReflect, locMVReflect, locNormalReflect, locInvertedCamera;
GLint				locMVPSkyBox;

// Six sides of a cube map
char *szCubeFaces[6] = { "pos_x.tga", "neg_x.tga", "pos_y.tga", "neg_y.tga", "pos_z.tga", "neg_z.tga" };




GLenum  cube[6] = { GL_TEXTURE_CUBE_MAP_POSITIVE_X,
GL_TEXTURE_CUBE_MAP_NEGATIVE_X,
GL_TEXTURE_CUBE_MAP_POSITIVE_Y,
GL_TEXTURE_CUBE_MAP_NEGATIVE_Y,
GL_TEXTURE_CUBE_MAP_POSITIVE_Z,
GL_TEXTURE_CUBE_MAP_NEGATIVE_Z };



void SetupRC()
{
	unsigned char *pBytes;
	//GLbyte *pBytes;
	GLint iWidth, iHeight, iComponents;
	GLenum eFormat;
	int i;
	int R;

	glGenTextures(1, &cubeTexture);//创建
	glBindTexture(GL_TEXTURE_CUBE_MAP, cubeTexture);//绑定纹理ID到一个纹理单元

	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);//设置纹理单元的过滤方式、插值方式等
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);//
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);//
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);//
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);//
	glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

	Mat img[6];
	img[0] = imread("C:\\Proj\\openvr-master\\samples\\hellovr_opengl\\ll0.jpg", CV_LOAD_IMAGE_COLOR);
	img[1] = imread("C:\\Proj\\openvr-master\\samples\\hellovr_opengl\\ll1.jpg", CV_LOAD_IMAGE_COLOR);
	img[2] = imread("C:\\Proj\\openvr-master\\samples\\hellovr_opengl\\ll2.jpg", CV_LOAD_IMAGE_COLOR);
	img[3] = imread("C:\\Proj\\openvr-master\\samples\\hellovr_opengl\\ll3.jpg", CV_LOAD_IMAGE_COLOR);
	img[4] = imread("C:\\Proj\\openvr-master\\samples\\hellovr_opengl\\ll4.jpg", CV_LOAD_IMAGE_COLOR);
	img[5] = imread("C:\\Proj\\openvr-master\\samples\\hellovr_opengl\\ll5.jpg", CV_LOAD_IMAGE_COLOR);

	R = img[0].rows;

	pBytes = (unsigned char*)malloc(R * R * 3 * sizeof(unsigned char));
	// Load Cube Map images
	for (i = 0; i < 6; i++)
	{
		// Load this texture map
		memcpy(pBytes, (char *)(img[i].data), R * R * 3 * sizeof(unsigned char));//拷贝 （目的 起始 字节数）
		//pBytes = gltReadTGABits(szCubeFaces[i], &iWidth, &iHeight, &iComponents, &eFormat);
		glTexImage2D(cube[i], 0, GL_RGB, R, R, 0, GL_BGR_EXT, GL_UNSIGNED_BYTE, pBytes);//format不要动 将内存中的数据拷贝到OpenGL纹理单元中
																						//glTexImage2D(cube[i], 0, iComponents, iWidth, iHeight, 0, eFormat, GL_UNSIGNED_BYTE, pBytes); 
	}

	glGenerateMipmap(GL_TEXTURE_CUBE_MAP);

	gltMakeCube(cubeBatch, 16.0f);

	skyBoxShader = gltLoadShaderPairWithAttributes("SkyBox.vp", "SkyBox.fp", 2,
		GLT_ATTRIBUTE_VERTEX, "vVertex",
		GLT_ATTRIBUTE_NORMAL, "vNormal");

	locMVPSkyBox = glGetUniformLocation(skyBoxShader, "mvpMatrix");

}




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 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 &vertdata);
	void AddCubeVertex(float fl0, float fl1, float fl2, float fl3, float fl4, std::vector &vertdata);

	void RenderControllerAxes();

	bool SetupStereoRenderTargets();
	void SetupCompanionWindow();
	void SetupCameras();

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

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

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

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

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

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

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

private: // SDL bookkeeping
	SDL_Window * m_pCompanionWindow;
	uint32_t m_nCompanionWindowWidth;
	uint32_t m_nCompanionWindowHeight;

	SDL_GLContext m_pContext;

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_unCompanionWindowVAO;
	GLuint m_glCompanionWindowIDVertBuffer;
	GLuint m_glCompanionWindowIDIndexBuffer;
	unsigned int m_uiCompanionWindowIndexSize;

	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 VertexDataWindow
	{
		Vector2 position;
		Vector2 texCoord;

		VertexDataWindow(const Vector2 & pos, const Vector2 tex) : position(pos), texCoord(tex) {	}
	};

	GLuint m_unSceneProgramID;
	GLuint m_unCompanionWindowProgramID;
	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: Outputs a set of optional arguments to debugging output, using
//          the printf format setting specified in fmt*.
//-----------------------------------------------------------------------------
void dprintf(const char *fmt, ...)
{
	va_list args;
	char buffer[2048];

	va_start(args, fmt);
	vsprintf_s(buffer, fmt, args);
	va_end(args);

	if (g_bPrintf)
		printf("%s", buffer);

	OutputDebugStringA(buffer);
}

//-----------------------------------------------------------------------------
// Purpose: Constructor
//-----------------------------------------------------------------------------
CMainApplication::CMainApplication(int argc, char *argv[])
	: m_pCompanionWindow(NULL)
	, m_pContext(NULL)
	, m_nCompanionWindowWidth(640)
	, m_nCompanionWindowHeight(320)
	, m_unSceneProgramID(0)
	, m_unCompanionWindowProgramID(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_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(true)
{

	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
	dprintf("Shutdown");
}


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

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


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
bool CMainApplication::BInit()
{
	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;
	}

	// 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));
		SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "VR_Init Failed", buf, NULL);
		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));
		SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "VR_Init Failed", buf, NULL);
		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_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_pCompanionWindow = SDL_CreateWindow("hellovr", 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;
	}

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

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


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

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

	std::string strWindowTitle = "hellovr - " + m_strDriver + " " + m_strDisplay;
	SDL_SetWindowTitle(m_pCompanionWindow, 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 = 30.0f;

	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: 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("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);
	}

	if (!CreateAllShaders())
		return false;

	//SetupTexturemaps();
	SetupScene();
	SetupCameras();
	SetupStereoRenderTargets();
	SetupCompanionWindow();
	SetupRenderModels();

	return true;
}


//-----------------------------------------------------------------------------
// Purpose: Initialize Compositor. Returns true if the compositor was
//          successfully initialized, false otherwise.
//-----------------------------------------------------------------------------
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_pContext)
	{
		glDebugMessageControl(GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, nullptr, GL_FALSE);
		glDebugMessageCallback(nullptr, nullptr);
		glDeleteBuffers(1, &m_glSceneVertBuffer);

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

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

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

	SDL_Quit();
}

//-----------------------------------------------------------------------------
// 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
				|| sdlEvent.key.keysym.sym == SDLK_q)
			{
				bRet = true;
			}
			if (sdlEvent.key.keysym.sym == SDLK_c)
			{
				m_bShowCubes = !m_bShowCubes;
			}
		}
	}

	// 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(state)))
		{
			m_rbShowTrackedDevice[unDevice] = state.ulButtonPressed == 0;
		}
	}

	return bRet;
}

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

	SDL_StartTextInput();
	SDL_ShowCursor(SDL_DISABLE);

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

		RenderFrame();
	}

	SDL_StopTextInput();
}


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


//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void CMainApplication::RenderFrame()
{
	// for now as fast as possible
	if (m_pHMD)
	{
		RenderControllerAxes();
		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);
	}

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

	// SwapWindow
	{
		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.
		glClearColor(0, 0, 0, 1);
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	}

	// Flush and wait for swap.
	if (m_bVblank)
	{
		glFlush();//强制刷新缓冲，保证绘图命令将被执行
		glFinish();
	}

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

		dprintf("PoseCount:%d(%s) Controllers:%d\n", m_iValidPoseCount, m_strPoseClasses.c_str(), m_iTrackedControllerCount);
	}

	UpdateHMDMatrixPose();
}


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

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

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

	glAttachShader(unProgramID, nSceneFragmentShader);
	glDe