source: GTP/trunk/App/Demos/Vis/FriendlyCulling/src/chcdemo.cpp @ 3014

// chcdemo.cpp : Defines the entry point for the console application.
//
#include "glInterface.h"
#include <math.h>
#include <time.h>
#include "common.h"
#include "RenderTraverser.h"
#include "SceneEntity.h"
#include "Vector3.h"
#include "Matrix4x4.h"
#include "ResourceManager.h"
#include "Bvh.h"
#include "Camera.h"
#include "Geometry.h"
#include "BvhLoader.h"
#include "FrustumCullingTraverser.h"
#include "StopAndWaitTraverser.h"
#include "CHCTraverser.h"
#include "CHCPlusPlusTraverser.h"
#include "Visualization.h"
#include "RenderState.h"
#include "Timer/PerfTimer.h"
#include "SceneQuery.h"
#include "RenderQueue.h"
#include "Material.h"
#include <Cg/cg.h>
#include <Cg/cgGL.h>
#include "glfont2.h"
#include "PerformanceGraph.h"
#include "Environment.h"
#include "Halton.h"
#include "Transform3.h"
#include "SampleGenerator.h"
#include "FrameBufferObject.h"
#include "DeferredRenderer.h"
#include "ShadowMapping.h"
#include "Light.h"
#include "SceneEntityConverter.h"
#include "ObjConverter.h"
#include "SkyPreetham.h"
#include "Texture.h"
#include "EntityMerger.h"



using namespace std;
using namespace CHCDemoEngine;


static Environment env;

#define MAX_DEPTH_CONST 10.0f

// fbo
FrameBufferObject *fbo = NULL;

GLuint fontTex;

/// the renderable scene geometry
SceneEntityContainer sceneEntities;
SceneEntityContainer sceneEntities2;

// traverses and renders the hierarchy
RenderTraverser *traverser = NULL;
/// the hierarchy
Bvh *bvh = NULL;
/// handles scene loading
ResourceManager *loader = NULL;
/// the scene camera
Camera *camera = NULL;
/// the scene camera
Camera *visCamera = NULL;
/// the visualization
Visualization *visualization = NULL;
/// the current render state
RenderState state;
/// the rendering algorithm
int renderMode = RenderTraverser::CHCPLUSPLUS;
// eye near plane distance
float nearDist = 0.2f;
float farDist = 1e6f;
/// the field of view
float fov = 50.0f;
/// the pixel threshold where a node is still considered invisible
int threshold;

int assumedVisibleFrames = 10;
int maxBatchSize = 50;

int trianglesPerVirtualLeaf = INITIAL_TRIANGLES_PER_VIRTUAL_LEAVES;

SceneQuery *sceneQuery = NULL;
RenderQueue *renderQueue = NULL;

// traverses and renders the hierarchy
RenderTraverser *shadowTraverser = NULL;

SkyPreetham *preetham = NULL;

/// the used render type for this render pass
enum RenderMethod
{
        RENDER_FIXED,
        RENDER_DEPTH_PASS,
        RENDER_DEFERRED,
        RENDER_DEPTH_PASS_DEFERRED,
        RENDER_NUM_RENDER_TYPES
};

/// one of four possible render methods
int renderMethod = RENDER_FIXED;


/// these values get scaled with the frame rate
static float keyForwardMotion = 30.0f;
static float keyRotation = 1.5f;

/// elapsed time in milliseconds
double elapsedTime = 1000.0f;
double algTime = 1000.0f;

static int winWidth = 1024;
static int winHeight = 768;

int shadowSize = 2048;

static float winAspectRatio = 1.0f;

double accumulatedTime = 1000;
float fps = 1e3f;

glfont::GLFont myfont;

// rendertexture
static int texWidth = 1024;
static int texHeight = 768;

int renderedObjects = 0;
int renderedNodes = 0;
int renderedTriangles = 0;

int issuedQueries = 0;
int traversedNodes = 0;
int frustumCulledNodes = 0;
int queryCulledNodes = 0;
int stateChanges = 0;
int numBatches = 0;


// mouse navigation state
int xEyeBegin = 0;
int yEyeBegin = 0;
int yMotionBegin = 0;
int verticalMotionBegin = 0;
int horizontalMotionBegin = 0;


bool leftKeyPressed = false;
bool rightKeyPressed = false;
bool upKeyPressed = false;
bool downKeyPressed = false;
bool descendKeyPressed = false;
bool ascendKeyPressed = false;

bool showHelp = false;
bool showStatistics = false;
bool showOptions = true;
bool showBoundingVolumes = false;
bool visMode = false;

bool useOptimization = false;
bool useTightBounds = true;
bool useRenderQueue = true;
bool useMultiQueries = true;
bool flyMode = true;

bool useGlobIllum = false;
bool useTemporalCoherence = true;
bool showAlgorithmTime = false;

bool useFullScreen = false;
bool useLODs = true;
bool moveLight = false;

bool useAdvancedShading = false;
bool showShadowMap = false;
bool renderLightView = false;

bool altKeyPressed = false;

bool useHDR = true;

static float ssaoTempCohFactor = 255.0;


PerfTimer frameTimer, algTimer;

static int sCurrentMrtSet = 0;

PerformanceGraph *perfGraph = NULL;


//DeferredRenderer::SAMPLING_METHOD samplingMethod = DeferredRenderer::SAMPLING_POISSON;
DeferredRenderer::SAMPLING_METHOD samplingMethod = DeferredRenderer::SAMPLING_QUADRATIC;

ShadowMap *shadowMap = NULL;
DirectionalLight *light = NULL;
DeferredRenderer *ssaoShader = NULL;

SceneEntity *cube = NULL;
SceneEntity *aeroplane = NULL;
SceneEntity *skyDome = NULL;



// function forward declarations
void InitExtensions();
void DisplayVisualization();
void InitGLstate();
void InitRenderTexture();
void InitCg();
void CleanUp();
void SetupEyeView();
void UpdateEyeMtx();
void SetupLighting();
void DisplayStats();
void Output(int x, int y, const char *string);
void DrawHelpMessage();
void RenderSky();
void RenderVisibleObjects();

void Begin2D();
void End2D();
void KeyBoard(unsigned char c, int x, int y);
void DrawStatistics();
void Display();
void Special(int c, int x, int y);
void KeyUp(unsigned char c, int x, int y);
void SpecialKeyUp(int c, int x, int y);
void Reshape(int w, int h);
void Mouse(int button, int state, int x, int y);
void LeftMotion(int x, int y);
void RightMotion(int x, int y);
void MiddleMotion(int x, int y);
void CalcDecimalPoint(string &str, int d);

RenderTraverser *CreateTraverser(Camera *cam);

void KeyHorizontalMotion(float shift);
void KeyVerticalMotion(float shift);

void PlaceViewer(const Vector3 &oldPos);

inline float KeyRotationAngle() { return keyRotation * elapsedTime * 1e-3f; }
inline float KeyShift() { return keyForwardMotion * elapsedTime * 1e-3f; }

void InitFBO();

void RightMotionLight(int x, int y);

void RenderShadowMap(float newfar);



/////////
//-- cg stuff

static CGcontext sCgContext = NULL;
static CGprogram sCgMrtVertexProgram = NULL;

static CGparameter sMaxDepthParam;
static CGparameter sMaxDepthParamTex;
static CGparameter sEyePosParamTex;
static CGparameter sEyePosParam;

static CGparameter sTLParam;
static CGparameter sTRParam;
static CGparameter sBRParam;
static CGparameter sBLParam;

static CGparameter sTLParamTex;
static CGparameter sTRParamTex;
static CGparameter sBRParamTex;
static CGparameter sBLParamTex;

static Matrix4x4 viewProjMat = IdentityMatrix();
static Matrix4x4 oldViewProjMat = IdentityMatrix();



static void cgErrorCallback()
{
        CGerror lastError = cgGetError();

        if(lastError)
        {
                printf("%s\n\n", cgGetErrorString(lastError));
                printf("%s\n", cgGetLastListing(sCgContext));
                
                printf("Cg error, exiting...\n");

                exit(0);
        }
}


static void PrintGLerror(char *msg)
{
        GLenum errCode;
        const GLubyte *errStr;
        
        if ((errCode = glGetError()) != GL_NO_ERROR) 
        {
                errStr = gluErrorString(errCode);
                fprintf(stderr,"OpenGL ERROR: %s: %s\n", errStr, msg);
        }
}


int main(int argc, char* argv[])
{
        int returnCode = 0;

        Vector3 camPos(.0f, .0f, .0f);
        Vector3 camDir(.0f, 1.0f, .0f);
        Vector3 lightDir(-0.8f, 1.0f, -0.7f);

        cout << "=== reading environment file ===" << endl << endl;

        string envFileName = "default.env";
        if (!env.Read(envFileName))
        {
                cerr << "loading environment " << envFileName << " failed!" << endl;
        }
        else
        {
                env.GetIntParam(string("assumedVisibleFrames"), assumedVisibleFrames);
                env.GetIntParam(string("maxBatchSize"), maxBatchSize);
                env.GetIntParam(string("trianglesPerVirtualLeaf"), trianglesPerVirtualLeaf);

                env.GetFloatParam(string("keyForwardMotion"), keyForwardMotion);
                env.GetFloatParam(string("keyRotation"), keyRotation);

                env.GetIntParam(string("winWidth"), winWidth);
                env.GetIntParam(string("winHeight"), winHeight);

                env.GetBoolParam(string("useFullScreen"), useFullScreen);
                env.GetFloatParam(string("tempCohFactor"), ssaoTempCohFactor);
                env.GetVectorParam(string("camPosition"), camPos);
                env.GetVectorParam(string("camDirection"), camDir);
                env.GetVectorParam(string("lightDirection"), lightDir);

                env.GetBoolParam(string("useLODs"), useLODs);
                env.GetIntParam(string("shadowSize"), shadowSize);

                env.GetBoolParam(string("useHDR"), useHDR);

                //env.GetStringParam(string("modelPath"), model_path);
                //env.GetIntParam(string("numSssaoSamples"), numSsaoSamples);


                cout << "assumedVisibleFrames: " << assumedVisibleFrames << endl; 
                cout << "maxBatchSize: " << maxBatchSize << endl;
                cout << "trianglesPerVirtualLeaf: " << trianglesPerVirtualLeaf << endl;

                cout << "keyForwardMotion: " << keyForwardMotion << endl;
                cout << "keyRotation: " << keyRotation << endl;
                cout << "winWidth: " << winWidth << endl;
                cout << "winHeight: " << winHeight << endl;
                cout << "useFullScreen: " << useFullScreen << endl;
                cout << "useLODs: " << useLODs << endl;
                cout << "camPosition: " << camPos << endl;
                cout << "temporal coherence: " << ssaoTempCohFactor << endl;
                cout << "shadow size: " << shadowSize << endl;

                //cout << "model path: " << model_path << endl;

                cout << "**** end parameters ****" << endl << endl;
        }

        ///////////////////////////

        camera = new Camera(winWidth, winHeight, fov);
        camera->SetNear(nearDist);
        camera->SetFar(1000);

        camera->SetDirection(camDir);
        camera->SetPosition(camPos);

        visCamera = new Camera(winWidth, winHeight, fov);
        visCamera->SetNear(0.0f);
        visCamera->Yaw(.5 * M_PI);

        // create a new light
        light = new DirectionalLight(lightDir, RgbaColor(1, 1, 1, 1), RgbaColor(1, 1, 1, 1));


        renderQueue = new RenderQueue(&state, camera);

        glutInitWindowSize(winWidth, winHeight);
        glutInit(&argc, argv);
        glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH | GLUT_MULTISAMPLE);
        //glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH);
        //glutInitDisplayString("samples=2");

        SceneEntity::SetUseLODs(useLODs);


        if (!useFullScreen)
        {
                glutCreateWindow("FriendlyCulling");
        }
        else
        {
                glutGameModeString( "1024x768:32@75" ); 
                glutEnterGameMode(); 
        }

        glutDisplayFunc(Display);
        glutKeyboardFunc(KeyBoard);
        glutSpecialFunc(Special);
        glutReshapeFunc(Reshape);
        glutMouseFunc(Mouse);
        glutIdleFunc(Display);
        glutKeyboardUpFunc(KeyUp);
        glutSpecialUpFunc(SpecialKeyUp);
        glutIgnoreKeyRepeat(true);

        // initialise gl graphics
        InitExtensions();
        InitGLstate();


        glEnable(GL_MULTISAMPLE_ARB);
        glHint(GL_MULTISAMPLE_FILTER_HINT_NV, GL_NICEST);

        LeftMotion(0, 0);
        MiddleMotion(0, 0);

        perfGraph = new PerformanceGraph(1000);

        loader = new ResourceManager();

        const string filename = string(model_path + "city.dem");

        if (loader->Load(filename, sceneEntities))
                cout << "model " << filename << " loaded" << endl;
        else
        {
                cerr << "loading model " << filename << " failed" << endl;
                CleanUp();
                exit(0);
        }

        const string bvh_filename = string(model_path + "city.bvh");
        BvhLoader bvhLoader;
        bvh = bvhLoader.Load(bvh_filename, sceneEntities);

        if (!bvh)
        {
                cerr << "loading bvh " << bvh_filename << " failed" << endl;
                CleanUp();
                exit(0);
        }
        

        // set far plane based on scene extent
        farDist = 10.0f * Magnitude(bvh->GetBox().Diagonal());
        bvh->SetVirtualLeaves(trianglesPerVirtualLeaf);

        camera->SetFar(Magnitude(bvh->GetBox().Diagonal()));
        
        InitCg();

        DeferredRenderer::Init(sCgContext);
        SkyPreetham::Init(sCgContext);

        Vector3 cubeCenter(470.398f, 240.364f, 182.5f);
        
        Matrix4x4 transl = TranslationMatrix(cubeCenter);
        

        SceneEntityContainer dummy;
        
        string skyDomeStr(model_path + "sky.dem");

        if (loader->Load(skyDomeStr, dummy))
                cout << "successfully loaded " << dummy.size() << " scene entities" << endl;
        else
        {
                cerr << "loading file " << skyDomeStr << " failed" << endl;

                CleanUp();
                exit(0);
        }

        skyDome = dummy[0];


        const float turbitiy = 5.0f;
        preetham = new SkyPreetham(turbitiy, skyDome);

        // initialize the render traverser
        traverser = CreateTraverser(camera);

        visualization = new Visualization(bvh, camera, NULL, &state);
        
        state.SetRenderPassType(RenderState::FIXED);
        sceneQuery = new SceneQuery(bvh->GetBox(), traverser);

        // frame time is restarted every frame
        frameTimer.Start();

        // the rendering loop
        glutMainLoop();

        // clean up
        CleanUp();

        return 0;
}


void InitCg(void) 
{
        // Setup Cg
        cgSetErrorCallback(cgErrorCallback);

        // Create cgContext.
        sCgContext = cgCreateContext();

        // get the best profile for this hardware
        RenderState::sCgFragmentProfile = cgGLGetLatestProfile(CG_GL_FRAGMENT);
        cgGLSetOptimalOptions(RenderState::sCgFragmentProfile);

        RenderState::sCgVertexProfile = cgGLGetLatestProfile(CG_GL_VERTEX);
        cgGLSetOptimalOptions(RenderState::sCgVertexProfile);

        sCgMrtVertexProgram = 
                cgCreateProgramFromFile(sCgContext, 
                                                                CG_SOURCE,
                                                                "src/shaders/mrt.cg", 
                                                                RenderState::sCgVertexProfile,
                                                                "vtx",
                                                                NULL);

        if (sCgMrtVertexProgram != NULL)
        {
                cgGLLoadProgram(sCgMrtVertexProgram);

                //sInvViewProjParam = cgGetNamedParameter(sCgMrtVertexProgram, "InvViewProj");
                Transform3::sModelMatrixParam = cgGetNamedParameter(sCgMrtVertexProgram, "ModelView");
        }

        RenderState::sCgMrtFragmentTexProgram = 
                cgCreateProgramFromFile(sCgContext, 
                                                                CG_SOURCE,
                                                                "src/shaders/mrt.cg", 
                                                                RenderState::sCgFragmentProfile,
                                                                "fragtex",
                                                                NULL);

        if (RenderState::sCgMrtFragmentTexProgram != NULL)
        {
                cgGLLoadProgram(RenderState::sCgMrtFragmentTexProgram);

                sMaxDepthParamTex = cgGetNamedParameter(RenderState::sCgMrtFragmentTexProgram, "maxDepth");
                sEyePosParamTex = cgGetNamedParameter(RenderState::sCgMrtFragmentTexProgram, "eyePos");
                RenderState::sTexParam = cgGetNamedParameter(RenderState::sCgMrtFragmentTexProgram, "tex");
        
                //const float maxDepth = MAX_DEPTH_CONST / farDist;
                const float maxDepth = 1.0f;

                cgGLSetParameter1f(sMaxDepthParamTex, maxDepth);

                sTLParamTex = cgGetNamedParameter(RenderState::sCgMrtFragmentTexProgram, "tl"); 
                sTRParamTex = cgGetNamedParameter(RenderState::sCgMrtFragmentTexProgram, "tr"); 
                sBRParamTex = cgGetNamedParameter(RenderState::sCgMrtFragmentTexProgram, "br"); 
                sBLParamTex = cgGetNamedParameter(RenderState::sCgMrtFragmentTexProgram, "bl"); 
        }
        else
                cerr << "fragment tex program failed to load" << endl;

        RenderState::sCgMrtFragmentProgram = 
                cgCreateProgramFromFile(sCgContext, 
                                                                CG_SOURCE,
                                                                "src/shaders/mrt.cg", 
                                                                RenderState::sCgFragmentProfile,
                                                                "frag",
                                                                NULL);

        if (RenderState::sCgMrtFragmentProgram != NULL)
        {
                cgGLLoadProgram(RenderState::sCgMrtFragmentProgram);

                sMaxDepthParam = cgGetNamedParameter(RenderState::sCgMrtFragmentProgram, "maxDepth");
                sEyePosParam = cgGetNamedParameter(RenderState::sCgMrtFragmentTexProgram, "eyePos");
                
                //const float maxDepth = MAX_DEPTH_CONST / farDist;
                const float maxDepth = 1.0f;

                cgGLSetParameter1f(sMaxDepthParam, maxDepth);

                sTLParam = cgGetNamedParameter(RenderState::sCgMrtFragmentProgram, "tl"); 
                sTRParam = cgGetNamedParameter(RenderState::sCgMrtFragmentProgram, "tr"); 
                sBRParam = cgGetNamedParameter(RenderState::sCgMrtFragmentProgram, "br"); 
                sBLParam = cgGetNamedParameter(RenderState::sCgMrtFragmentProgram, "bl"); 
        }
        else
                cerr << "fragment program failed to load" << endl;
        

        PrintGLerror("init");

        cout << "cg initialization successful" << endl;
}


void InitFBO()
{
        PrintGLerror("fbo start");

        // this fbo basicly stores the scene information we get from standard rendering of a frame
        // we store colors, normals, positions (for the ssao)
        fbo = new FrameBufferObject(texWidth, texHeight, FrameBufferObject::DEPTH_32);
        //fbo = new FrameBufferObject(texWidth, texHeight, FrameBufferObject::DEPTH_24);

        // the diffuse color buffer
        fbo->AddColorBuffer(ColorBufferObject::RGBA_FLOAT_32, ColorBufferObject::WRAP_CLAMP_TO_EDGE, ColorBufferObject::FILTER_NEAREST, ColorBufferObject::FILTER_NEAREST);
        // the normals buffer
        fbo->AddColorBuffer(ColorBufferObject::RGBA_FLOAT_16, ColorBufferObject::WRAP_CLAMP_TO_EDGE, ColorBufferObject::FILTER_NEAREST);
        // the positions buffer
        //fbo->AddColorBuffer(ColorBufferObject::RGBA_FLOAT_32, ColorBufferObject::WRAP_CLAMP_TO_EDGE, ColorBufferObject::FILTER_NEAREST);
        fbo->AddColorBuffer(ColorBufferObject::RGB_UBYTE, ColorBufferObject::WRAP_CLAMP_TO_EDGE, ColorBufferObject::FILTER_NEAREST);
        // another color buffer
        fbo->AddColorBuffer(ColorBufferObject::RGBA_FLOAT_32, ColorBufferObject::WRAP_CLAMP_TO_EDGE, ColorBufferObject::FILTER_NEAREST, ColorBufferObject::FILTER_NEAREST);

        PrintGLerror("fbo");
}


bool InitFont(void)
{
        glEnable(GL_TEXTURE_2D);

        glGenTextures(1, &fontTex);
        glBindTexture(GL_TEXTURE_2D, fontTex);
        if (!myfont.Create("data/fonts/verdana.glf", fontTex))
                return false;

        glDisable(GL_TEXTURE_2D);
        
        return true;
}


void InitGLstate() 
{
        glClearColor(0.4f, 0.4f, 0.4f, 1.0f);
        
        glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
        glPixelStorei(GL_PACK_ALIGNMENT,1); 
        
        glDepthFunc(GL_LESS);
        glEnable(GL_DEPTH_TEST);

        glColor3f(1.0f, 1.0f, 1.0f);
        glShadeModel(GL_SMOOTH);
        
        glMaterialf(GL_FRONT, GL_SHININESS, 64);
        glEnable(GL_NORMALIZE);
                
        glDisable(GL_ALPHA_TEST);
        glAlphaFunc(GL_GEQUAL, 0.5f);

        glFrontFace(GL_CCW);
        glCullFace(GL_BACK);
        glEnable(GL_CULL_FACE);

        glDisable(GL_TEXTURE_2D);

        GLfloat ambientColor[] = {0.2, 0.2, 0.2, 1.0};
        GLfloat diffuseColor[] = {1.0, 0.0, 0.0, 1.0};
        GLfloat specularColor[] = {0.0, 0.0, 0.0, 1.0};

        glMaterialfv(GL_FRONT, GL_AMBIENT, ambientColor);
        glMaterialfv(GL_FRONT, GL_DIFFUSE, diffuseColor);
        glMaterialfv(GL_FRONT, GL_SPECULAR, specularColor);

        glDepthFunc(GL_LESS);

        if (!InitFont())
                cerr << "font creation failed" << endl;
        else
                cout << "successfully created font" << endl;


        //////////////////////////////

        //GLfloat lmodel_ambient[] = {1.0f, 1.0f, 1.0f, 1.0f};
        GLfloat lmodel_ambient[] = {0.7f, 0.7f, 0.8f, 1.0f};

        glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
        //glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER, GL_TRUE);
        glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER, GL_FALSE);
        glLightModeli(GL_LIGHT_MODEL_COLOR_CONTROL_EXT, GL_SINGLE_COLOR_EXT);
}


void DrawHelpMessage() 
{
        const char *message[] = 
        {
                "Help information",
                "",
                "'F1'           - shows/dismisses this message",
                "'F2'           - shows/hides bird eye view",
                "'F3'           - shows/hides bounds (boxes or tight bounds)",
                "'F4',          - shows/hides parameters",
                "'F5'           - shows/hides statistics",
                "'F6',          - toggles between fly/walkmode",
                "'F7',          - cycles throw render modes",
                "'F8',          - enables/disables ambient occlusion (only deferred)",
                "'F9',          - shows pure algorithm render time (using glFinish)",
                "'SPACE'        - cycles through occlusion culling algorithms",
                "",
                "'MOUSE LEFT'        - turn left/right, move forward/backward",
                "'MOUSE RIGHT'       - turn left/right, move forward/backward",
                "'MOUSE MIDDLE'      - move up/down, left/right",
                "'CURSOR UP/DOWN'    - move forward/backward",
                "'CURSOR LEFT/RIGHT' - turn left/right",
                "",
                "'-'/'+'        - decreases/increases max batch size",
                "'1'/'2'        - downward/upward motion",
                "'3'/'4'        - decreases/increases triangles per virtual bvh leaf (sets bvh depth)",
                "'5'/'6'        - decreases/increases assumed visible frames",
                "",
                "'R'            - use render queue",
                "'B'            - use tight bounds",
                "'M'            - use multiqueries",
                "'O'            - use CHC optimization (geometry queries for leaves)",
                0,
        };
        
        
        glColor4f(0.0f, 1.0f , 0.0f, 0.2f); // 20% green. 

        glRecti(30, 30, winWidth - 30, winHeight - 30);

        glEnd();

        glColor3f(1.0f, 1.0f, 1.0f);
        
        glEnable(GL_TEXTURE_2D);
        myfont.Begin();

        int x = 40, y = 30;

        for(int i = 0; message[i] != 0; ++ i) 
        {
                if(message[i][0] == '\0') 
                {
                        y += 15;
                } 
                else 
                {
                        myfont.DrawString(message[i], x, winHeight - y);
                        y += 25;
                }
        }
        glDisable(GL_TEXTURE_2D);
}


RenderTraverser *CreateTraverser(Camera *cam)
{
        RenderTraverser *tr;
        
        bvh->ResetNodeClassifications();

        switch (renderMode)
        {
        case RenderTraverser::CULL_FRUSTUM:
                tr = new FrustumCullingTraverser();
                break;
        case RenderTraverser::STOP_AND_WAIT:
                tr = new StopAndWaitTraverser();
                break;
        case RenderTraverser::CHC:
                tr = new CHCTraverser();
                break;
        case RenderTraverser::CHCPLUSPLUS:
                tr = new CHCPlusPlusTraverser();
                break;
        
        default:
                tr = new FrustumCullingTraverser();
        }

        tr->SetCamera(cam);
        tr->SetHierarchy(bvh);
        tr->SetRenderQueue(renderQueue);
        tr->SetRenderState(&state);
        tr->SetUseOptimization(useOptimization);
        tr->SetUseRenderQueue(useRenderQueue);
        tr->SetVisibilityThreshold(threshold);
        tr->SetAssumedVisibleFrames(assumedVisibleFrames);
        tr->SetMaxBatchSize(maxBatchSize);
        tr->SetUseMultiQueries(useMultiQueries);
        tr->SetUseTightBounds(useTightBounds);
        tr->SetUseDepthPass((renderMethod == RENDER_DEPTH_PASS) || (renderMethod == RENDER_DEPTH_PASS_DEFERRED));
        tr->SetRenderQueue(renderQueue);

        return tr;
}


void SetupLighting()
{
        glEnable(GL_LIGHT0);
        glDisable(GL_LIGHT1);
        
        Vector3 lightDir = -light->GetDirection();


        ///////////
        //-- first light: sunlight

        GLfloat ambient[] = {0.25f, 0.25f, 0.3f, 1.0f};
        GLfloat diffuse[] = {1.0f, 0.95f, 0.85f, 1.0f};
        GLfloat specular[] = {1.0f, 1.0f, 1.0f, 1.0f};
        

        const bool useToneMapping = ((renderMethod == RENDER_DEPTH_PASS_DEFERRED) || (renderMethod == RENDER_DEFERRED)) && useHDR;

        Vector3 sunAmbient;
        Vector3 sunDiffuse;

        preetham->ComputeSunColor(lightDir, sunAmbient, sunDiffuse, !useToneMapping);

        ambient[0] = sunAmbient.x;
        ambient[1] = sunAmbient.y;
        ambient[2] = sunAmbient.z;

        // no tone mapping => scale
        if (!useToneMapping)
        {
                const float maxComponent = sunDiffuse.MaxComponent();
                sunDiffuse /= maxComponent;
        }

        diffuse[0] = sunDiffuse.x;
        diffuse[1] = sunDiffuse.y;
        diffuse[2] = sunDiffuse.z;

        glLightfv(GL_LIGHT0, GL_AMBIENT, ambient);
        glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse);
        glLightfv(GL_LIGHT0, GL_SPECULAR, specular);

        GLfloat position[] = {lightDir.x, lightDir.y, lightDir.z, 0.0f};
        glLightfv(GL_LIGHT0, GL_POSITION, position);
}


void SetupEyeView()
{
        // store matrix of last frame
        oldViewProjMat = viewProjMat;

        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        gluPerspective(fov, winAspectRatio, nearDist, farDist);

        glMatrixMode(GL_MODELVIEW);
        
        // set up the camera view
        camera->SetupCameraView();

                
        /////////////////

        Matrix4x4 matViewing, matProjection;

        camera->GetModelViewMatrix(matViewing);
        camera->GetProjectionMatrix(matProjection);

        // store matrix for later use
        viewProjMat = matViewing * matProjection;
        
        if ((renderMethod == RENDER_DEFERRED) || (renderMethod == RENDER_DEPTH_PASS_DEFERRED))
        {
                cgGLSetMatrixParameterfc(Transform3::sModelMatrixParam, (const float *)IdentityMatrix().x);
        }
}


void KeyHorizontalMotion(float shift)
{
        Vector3 hvec = -camera->GetDirection();
        hvec.z = 0;

        Vector3 pos = camera->GetPosition();
        pos += hvec * shift;
        
        camera->SetPosition(pos);
}


void KeyVerticalMotion(float shift)
{
        Vector3 uvec = Vector3(0, 0, shift);

        Vector3 pos = camera->GetPosition();
        pos += uvec;
        
        camera->SetPosition(pos);
}


static void ComputeViewVectors(Vector3 &tl, Vector3 &tr, Vector3 &bl, Vector3 &br)
{
        Vector3 ftl, ftr, fbl, fbr, ntl, ntr, nbl, nbr;

        camera->ComputePoints(ftl, ftr, fbl, fbr, ntl, ntr, nbl, nbr);

        bl = Normalize(nbl - fbl);
        br = Normalize(nbr - fbr);
        tl = Normalize(ntl - ftl);
        tr = Normalize(ntr - ftr);
}


void InitDeferredRendering()
{
        if (!fbo) InitFBO();
        fbo->Bind();

        // multisampling does not work with deferred shading
        glDisable(GL_MULTISAMPLE_ARB);

        state.SetRenderPassType(RenderState::DEFERRED);

        cgGLEnableProfile(RenderState::sCgVertexProfile);
        cgGLBindProgram(sCgMrtVertexProgram);

        cgGLEnableProfile(RenderState::sCgFragmentProfile);
        cgGLBindProgram(RenderState::sCgMrtFragmentProgram);

        const Vector3 pos = camera->GetPosition();

        cgGLSetParameter3f(sEyePosParam, pos.x, pos.y, pos.z);
        cgGLSetParameter3f(sEyePosParamTex, pos.x, pos.y, pos.z);

        Vector3 tl, tr, bl, br;
        ComputeViewVectors(tl, tr, bl, br);

        cgGLSetParameter3f(sBLParam, bl.x, bl.y, bl.z);
        cgGLSetParameter3f(sBRParam, br.x, br.y, br.z);
        cgGLSetParameter3f(sTLParam, tl.x, tl.y, tl.z);
        cgGLSetParameter3f(sTRParam, tr.x, tr.y, tr.z);

        cgGLSetParameter3f(sBLParamTex, bl.x, bl.y, bl.z);
        cgGLSetParameter3f(sBRParamTex, br.x, br.y, br.z);
        cgGLSetParameter3f(sTLParamTex, tl.x, tl.y, tl.z);
        cgGLSetParameter3f(sTRParamTex, tr.x, tr.y, tr.z);

        // draw to 3 color buffers
        // a color, normal, and positions buffer
        if (sCurrentMrtSet == 0)
        {
                DeferredRenderer::colorBufferIdx = 0;
                glDrawBuffers(2, mrt);
        }
        else 
        {
                DeferredRenderer::colorBufferIdx = 3;
                glDrawBuffers(2, mrt2);
        }

        sCurrentMrtSet = 1 - sCurrentMrtSet;
}


// the main rendering loop
void Display() 
{       
        Vector3 oldPos = camera->GetPosition();

        if (leftKeyPressed)
                camera->Pitch(KeyRotationAngle());
        if (rightKeyPressed)
                camera->Pitch(-KeyRotationAngle());
        if (upKeyPressed)
                KeyHorizontalMotion(-KeyShift());
        if (downKeyPressed)
                KeyHorizontalMotion(KeyShift());
        if (ascendKeyPressed)
                KeyVerticalMotion(KeyShift());
        if (descendKeyPressed)
                KeyVerticalMotion(-KeyShift());

        // place view on ground
        if (!flyMode) PlaceViewer(oldPos);

        if (showAlgorithmTime)
        {
                glFinish();
                algTimer.Start();
        }
        


        if ((!shadowMap || !shadowTraverser) && (showShadowMap || renderLightView))
        {
                if (!shadowMap)
                        shadowMap = new ShadowMap(light, shadowSize, bvh->GetBox(), camera);

                if (!shadowTraverser)
                        shadowTraverser = CreateTraverser(shadowMap->GetShadowCamera());

        }

        
        // bring eye modelview matrix up-to-date
        SetupEyeView();

        // hack
        int oldRenderMethod = renderMethod;

        if (renderLightView)
                renderMethod = RenderState::FIXED;

        glEnableClientState(GL_VERTEX_ARRAY);


        // render with the specified method (forward rendering, forward + depth, deferred)
        switch (renderMethod)
        {
        case RENDER_FIXED:
        
                glEnable(GL_MULTISAMPLE_ARB);
                
                state.SetRenderPassType(RenderState::FIXED);
                glEnable(GL_LIGHTING);

                cgGLDisableProfile(RenderState::sCgFragmentProfile);
                cgGLDisableProfile(RenderState::sCgVertexProfile);

                glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

                glEnableClientState(GL_NORMAL_ARRAY);

                break;

        case RENDER_DEPTH_PASS_DEFERRED:

                glDisable(GL_MULTISAMPLE_ARB);
                state.SetUseAlphaToCoverage(false);

                state.SetRenderPassType(RenderState::DEPTH_PASS);

                if (!fbo) InitFBO(); fbo->Bind();

                glDrawBuffers(1, mrt);

                cgGLDisableProfile(RenderState::sCgFragmentProfile);
                cgGLDisableProfile(RenderState::sCgVertexProfile);

                glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

                // the scene is rendered withouth any shading   
                glShadeModel(GL_FLAT);
                glDisable(GL_LIGHTING);
                glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);


                break;

        case RENDER_DEPTH_PASS:

                glEnable(GL_MULTISAMPLE_ARB);

                cgGLDisableProfile(RenderState::sCgFragmentProfile);
                cgGLDisableProfile(RenderState::sCgVertexProfile);

                state.SetRenderPassType(RenderState::DEPTH_PASS);

                // the scene is rendered withouth any shading   
                glShadeModel(GL_FLAT);
                glDisable(GL_LIGHTING);
        
                glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
                glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);


                break;
        
        case RenderState::DEFERRED:

                if (showShadowMap && !renderLightView)
                        RenderShadowMap(camera->GetFar());

                //glPushAttrib(GL_VIEWPORT_BIT);
                glViewport(0, 0, texWidth, texHeight);

                InitDeferredRendering();
                
                glEnableClientState(GL_NORMAL_ARRAY);
                glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

                break;
        }

        glDepthFunc(GL_LESS);

        glDisable(GL_TEXTURE_2D);
        glDisableClientState(GL_TEXTURE_COORD_ARRAY);
                

        // reset lod levels for current frame
        LODLevel::InitFrame(camera->GetPosition());

        // set up lights
        SetupLighting();


        if (renderLightView)
        {
                // change CHC++ set of state variables (must be done for each change of camera because
                // otherwise the temporal coherency is broken
                BvhNode::SetCurrentState(1);
                shadowMap->RenderShadowView(shadowTraverser, viewProjMat);
                BvhNode::SetCurrentState(0);
        }
        else
        {
                // actually render the scene geometry using the specified algorithm
                traverser->RenderScene();
        }


        /////////
        //-- do the rest of the rendering
        
        // reset depth pass and render visible objects
        if ((renderMethod == RENDER_DEPTH_PASS) ||
                (renderMethod == RENDER_DEPTH_PASS_DEFERRED))
        {
                RenderVisibleObjects();
        }
        

        ///////////////
        //-- render sky

        // q: should we render sky after deferred shading? 
        // this would conveniently solves some issues (e.g, skys without shadows)

        RenderSky();


        if ((renderMethod == RENDER_DEFERRED) ||
                (renderMethod == RENDER_DEPTH_PASS_DEFERRED))
        {
                FrameBufferObject::Release();

                cgGLDisableProfile(RenderState::sCgVertexProfile);
                cgGLDisableProfile(RenderState::sCgFragmentProfile);

                if (!ssaoShader) ssaoShader = 
                        new DeferredRenderer(texWidth, texHeight, camera, farDist / MAX_DEPTH_CONST);
                
                DeferredRenderer::SHADING_METHOD shadingMethod;

                if (useAdvancedShading)
                {
                        if (useGlobIllum)
                                shadingMethod = DeferredRenderer::GI;
                        else
                                shadingMethod = DeferredRenderer::SSAO;
                }
                else
                        shadingMethod = DeferredRenderer::DEFAULT;


                ssaoShader->SetShadingMethod(shadingMethod);
                ssaoShader->SetSamplingMethod(samplingMethod);
                ssaoShader->SetUseTemporalCoherence(useTemporalCoherence);

                ShadowMap *sm = showShadowMap ? shadowMap : NULL;
                ssaoShader->Render(fbo, oldViewProjMat, viewProjMat, ssaoTempCohFactor, light, useHDR, sm);
        }


        state.SetRenderPassType(RenderState::FIXED);
        state.Reset();


        glDisableClientState(GL_VERTEX_ARRAY);
        glDisableClientState(GL_NORMAL_ARRAY);
        
        renderMethod = oldRenderMethod;


        ///////////


        if (showAlgorithmTime)
        {
                glFinish();

                algTime = algTimer.Elapsedms();
                perfGraph->AddData(algTime);

                perfGraph->Draw();
        }
        else
        {
                if (visMode) DisplayVisualization();
        }

        glFlush();

        const bool restart = true;
        elapsedTime = frameTimer.Elapsedms(restart);

        DisplayStats();

        glutSwapBuffers();
}


#pragma warning( disable : 4100 )
void KeyBoard(unsigned char c, int x, int y) 
{
        switch(c) 
        {
        case 27:
                CleanUp();
                exit(0);
                break;
        case 32: // space
                renderMode = (renderMode + 1) % RenderTraverser::NUM_TRAVERSAL_TYPES;

                DEL_PTR(traverser);
                traverser = CreateTraverser(camera);

                if (shadowTraverser)
                {
                        // shadow traverser has to be recomputed
                        DEL_PTR(shadowTraverser);
                        shadowTraverser = CreateTraverser(shadowMap->GetShadowCamera());
                }

                break;
        case '+':
                if (maxBatchSize < 10)
                        maxBatchSize = 10;
                else
                        maxBatchSize += 10;

                traverser->SetMaxBatchSize(maxBatchSize);
                break;
        case '-':
                maxBatchSize -= 10;
                if (maxBatchSize < 0) maxBatchSize = 1;
                traverser->SetMaxBatchSize(maxBatchSize);               
                break;
        case 'M':
        case 'm':
                useMultiQueries = !useMultiQueries;
                traverser->SetUseMultiQueries(useMultiQueries);
                break;
        case '1':
                descendKeyPressed = true;
                break;
        case '2':
                ascendKeyPressed = true;
                break;
        case '3':
                if (trianglesPerVirtualLeaf >= 100)
                        trianglesPerVirtualLeaf -= 100;
                bvh->SetVirtualLeaves(trianglesPerVirtualLeaf);
                break;
        case '4':
                trianglesPerVirtualLeaf += 100;
                bvh->SetVirtualLeaves(trianglesPerVirtualLeaf);
                break;
        case '5':
                assumedVisibleFrames -= 1;
                if (assumedVisibleFrames < 1) assumedVisibleFrames = 1;
                traverser->SetAssumedVisibleFrames(assumedVisibleFrames);
                break;
        case '6':
                assumedVisibleFrames += 1;
                traverser->SetAssumedVisibleFrames(assumedVisibleFrames);               
                break;
        case '7':
                ssaoTempCohFactor *= 0.5f;
                break;
        case '8':
                ssaoTempCohFactor *= 2.0f;
                //if (ssaoTempCohFactor > 1.0f) ssaoExpFactor = 1.0f;
                break;
        case '9':
                useLODs = !useLODs;
                SceneEntity::SetUseLODs(useLODs);
                break;
        case 'P':
        case 'p':
                samplingMethod = DeferredRenderer::SAMPLING_METHOD((samplingMethod + 1) % 3);
                cout << "ssao sampling method: " << samplingMethod << endl;
                break;
        case 'Y':
        case 'y':
                showShadowMap = !showShadowMap;
                break;
        case 'g':
        case 'G':
                useGlobIllum = !useGlobIllum;
                break;
        case 't':
        case 'T':
                useTemporalCoherence = !useTemporalCoherence;
                break;
        case 'o':
        case 'O':
                useOptimization = !useOptimization;
                traverser->SetUseOptimization(useOptimization);
                break;
        case 'a':
        case 'A':
                leftKeyPressed = true;
                break;
        case 'd':
        case 'D':
                rightKeyPressed = true;
                break;
        case 'w':
        case 'W':
                upKeyPressed = true;
                break;
        case 's':
        case 'S':
                downKeyPressed = true;
                break;
        case 'r':
        case 'R':
                useRenderQueue = !useRenderQueue;
                traverser->SetUseRenderQueue(useRenderQueue);
                
                break;
        case 'b':
        case 'B':
                useTightBounds = !useTightBounds;
                traverser->SetUseTightBounds(useTightBounds);
                break;
        case 'l':
        case 'L':
                renderLightView = !renderLightView;
                break;
        case 'h':
        case 'H':
                useHDR = !useHDR;
                break;
        default:
                return;
        }

        glutPostRedisplay();
}


void SpecialKeyUp(int c, int x, int y) 
{
        switch (c) 
        {
        case GLUT_KEY_LEFT:
                leftKeyPressed = false;
                break;
        case GLUT_KEY_RIGHT:
                rightKeyPressed = false;
                break;
        case GLUT_KEY_UP:
                upKeyPressed = false;
                break;
        case GLUT_KEY_DOWN:
                downKeyPressed = false;
                break;
        case GLUT_ACTIVE_ALT:
                altKeyPressed = false;
                break;
        default:
                return;
        }
}


void KeyUp(unsigned char c, int x, int y) 
{
        switch (c) 
        {

        case 'A':
        case 'a':
                leftKeyPressed = false;
                break;
        case 'D':
        case 'd':
                rightKeyPressed = false;
                break;
        case 'W':
        case 'w':
                upKeyPressed = false;
                break;
        case 'S':
        case 's':
                downKeyPressed = false;
                break;
        case '1':
                descendKeyPressed = false;
                break;
        case '2':
                ascendKeyPressed = false;
                break;
        
        default:
                return;
        }
        //glutPostRedisplay();
}


void Special(int c, int x, int y) 
{
        switch(c) 
        {
        case GLUT_KEY_F1:
                showHelp = !showHelp;
                break;
        case GLUT_KEY_F2:
                visMode = !visMode;
                break;
        case GLUT_KEY_F3:
                showBoundingVolumes = !showBoundingVolumes;
                traverser->SetShowBounds(showBoundingVolumes);
                break;
        case GLUT_KEY_F4:
                showOptions = !showOptions;
                break;
        case GLUT_KEY_F5:
                showStatistics = !showStatistics;
                break;
        case GLUT_KEY_F6:
                flyMode = !flyMode;
                break;
        case GLUT_KEY_F7:

                renderMethod = (renderMethod + 1) % 4;

                traverser->SetUseDepthPass(
                        (renderMethod == RENDER_DEPTH_PASS) || 
                        (renderMethod == RENDER_DEPTH_PASS_DEFERRED)
                        );
                
                break;
        case GLUT_KEY_F8:
                useAdvancedShading = !useAdvancedShading;

                break;
        case GLUT_KEY_F9:
                showAlgorithmTime = !showAlgorithmTime;
                break;
        case GLUT_KEY_F10:
                moveLight = !moveLight;
                break;
        case GLUT_KEY_LEFT:
                {
                        leftKeyPressed = true;
                        camera->Pitch(KeyRotationAngle());
                }
                break;
        case GLUT_KEY_RIGHT:
                {
                        rightKeyPressed = true;
                        camera->Pitch(-KeyRotationAngle());
                }
                break;
        case GLUT_KEY_UP:
                {
                        upKeyPressed = true;
                        KeyHorizontalMotion(KeyShift());
                }
                break;
        case GLUT_KEY_DOWN:
                {
                        downKeyPressed = true;
                        KeyHorizontalMotion(-KeyShift());
                }
                break;
        default:
                return;

        }

        glutPostRedisplay();
}

#pragma warning( default : 4100 )


void Reshape(int w, int h) 
{
        winAspectRatio = 1.0f;

        glViewport(0, 0, w, h);
        
        winWidth = w;
        winHeight = h;

        if (w) winAspectRatio = (float) w / (float) h;

        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();

        gluPerspective(fov, winAspectRatio, nearDist, farDist);

        glMatrixMode(GL_MODELVIEW);

        glutPostRedisplay();
}


void Mouse(int button, int state, int x, int y) 
{
        if ((button == GLUT_LEFT_BUTTON) && (state == GLUT_DOWN))
        {
                xEyeBegin = x;
                yMotionBegin = y;

                glutMotionFunc(LeftMotion);
        }
        else if ((button == GLUT_RIGHT_BUTTON) && (state == GLUT_DOWN))
        {
                xEyeBegin = x;
                yEyeBegin = y;
                yMotionBegin = y;

                if (!moveLight)
                        glutMotionFunc(RightMotion);
                else
                        glutMotionFunc(RightMotionLight);
        }
        else if ((button == GLUT_MIDDLE_BUTTON) && (state == GLUT_DOWN))
        {
                horizontalMotionBegin = x;
                verticalMotionBegin = y;
                glutMotionFunc(MiddleMotion);
        }

        glutPostRedisplay();
}


/**     rotation for left/right mouse drag
        motion for up/down mouse drag
*/
void LeftMotion(int x, int y) 
{
        Vector3 viewDir = camera->GetDirection();
        Vector3 pos = camera->GetPosition();

        // don't move in the vertical direction
        Vector3 horView(viewDir[0], viewDir[1], 0);
        
        float eyeXAngle = 0.2f *  M_PI * (xEyeBegin - x) / 180.0;

        camera->Pitch(eyeXAngle);

        pos += horView * (yMotionBegin - y) * 0.2f;
        
        camera->SetPosition(pos);
        
        xEyeBegin = x;
        yMotionBegin = y;

        glutPostRedisplay();
}


void RightMotionLight(int x, int y) 
{
        float theta = 0.2f * M_PI * (xEyeBegin - x) / 180.0f;
        float phi = 0.2f * M_PI * (yMotionBegin - y) / 180.0f;
        
        Vector3 lightDir = light->GetDirection();

        Matrix4x4 roty = RotationYMatrix(theta);
        Matrix4x4 rotx = RotationXMatrix(phi);

        lightDir = roty * lightDir;
        lightDir = rotx * lightDir;

        // normalize to avoid accumulating errors
        lightDir.Normalize();

        light->SetDirection(lightDir);

        xEyeBegin = x;
        yMotionBegin = y;

        glutPostRedisplay();
}


/**     rotation for left / right mouse drag
        motion for up / down mouse drag
*/
void RightMotion(int x, int y) 
{
        float eyeXAngle = 0.2f *  M_PI * (xEyeBegin - x) / 180.0;
        float eyeYAngle = -0.2f *  M_PI * (yEyeBegin - y) / 180.0;

        camera->Yaw(eyeYAngle);
        camera->Pitch(eyeXAngle);

        xEyeBegin = x;
        yEyeBegin = y;

        glutPostRedisplay();
}


// strafe
void MiddleMotion(int x, int y) 
{
        Vector3 viewDir = camera->GetDirection();
        Vector3 pos = camera->GetPosition();

        // the 90 degree rotated view vector 
        // y zero so we don't move in the vertical
        Vector3 rVec(viewDir[0], viewDir[1], 0);
        
        Matrix4x4 rot = RotationZMatrix(M_PI * 0.5f);
        rVec = rot * rVec;
        
        pos -= rVec * (x - horizontalMotionBegin) * 0.1f;
        pos[2] += (verticalMotionBegin - y) * 0.1f;

        camera->SetPosition(pos);

        horizontalMotionBegin = x;
        verticalMotionBegin = y;

        glutPostRedisplay();
}


void InitExtensions(void) 
{
        GLenum err = glewInit();

        if (GLEW_OK != err) 
        {
                // problem: glewInit failed, something is seriously wrong
                fprintf(stderr,"Error: %s\n", glewGetErrorString(err));
                exit(1);
        }
        if  (!GLEW_ARB_occlusion_query)
        {
                printf("I require the GL_ARB_occlusion_query to work.\n");
                exit(1);
        }
}


void Begin2D() 
{
        glDisable(GL_LIGHTING);
        glDisable(GL_DEPTH_TEST);

        glMatrixMode(GL_PROJECTION);
        glPushMatrix();
        glLoadIdentity();

        gluOrtho2D(0, winWidth, 0, winHeight);

        glMatrixMode(GL_MODELVIEW);
        glPushMatrix();
        glLoadIdentity();
}


void End2D() 
{
        glMatrixMode(GL_PROJECTION);
        glPopMatrix();

        glMatrixMode(GL_MODELVIEW);
        glPopMatrix();

        glEnable(GL_LIGHTING);
        glEnable(GL_DEPTH_TEST);
}


// displays the visualisation of culling algorithm
void DisplayVisualization()
{
        visualization->SetFrameId(traverser->GetCurrentFrameId());
        
        Begin2D();
        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
        glEnable(GL_BLEND);
        glColor4f(0.0f ,0.0f, 0.0f, 0.5f); 

        glRecti(winWidth - winWidth / 3, winHeight - winHeight / 3, winWidth, winHeight);
        glDisable(GL_BLEND);
        End2D();
        
        
        AxisAlignedBox3 box = bvh->GetBox();

        const float offs = box.Size().x * 0.3f;
        
        Vector3 vizpos = Vector3(box.Min().x, box.Min().y  - box.Size().y * 0.35f, box.Min().z + box.Size().z * 50);
        
        visCamera->SetPosition(vizpos);
        visCamera->ResetPitchAndYaw();
        
        glPushAttrib(GL_VIEWPORT_BIT);
        glViewport(winWidth - winWidth / 3, winHeight - winHeight / 3, winWidth / 3, winHeight / 3);

        glMatrixMode(GL_PROJECTION);
        glPushMatrix();

        glLoadIdentity();
        
        glOrtho(-offs, offs, -offs, offs, 0.0f, box.Size().z * 100.0f); 

        glMatrixMode(GL_MODELVIEW);
        glPushMatrix();

        visCamera->SetupCameraView();

        Matrix4x4 rotZ = RotationZMatrix(-camera->GetPitch());
        glMultMatrixf((float *)rotZ.x);

        // inverse translation in order to fix current position
        Vector3 pos = camera->GetPosition();
        glTranslatef(-pos.x, -pos.y, -pos.z);


        GLfloat position[] = {0.8f, 1.0f, 1.5f, 0.0f};
        glLightfv(GL_LIGHT0, GL_POSITION, position);

        GLfloat position1[] = {bvh->GetBox().Center().x, bvh->GetBox().Max().y, bvh->GetBox().Center().z, 1.0f};
        glLightfv(GL_LIGHT1, GL_POSITION, position1);

        glClear(GL_DEPTH_BUFFER_BIT);


        ////////////
        //-- visualization of the occlusion culling

        visualization->Render();

        
        // reset previous settings
        glPopAttrib();

        glMatrixMode(GL_PROJECTION);
        glPopMatrix();
        glMatrixMode(GL_MODELVIEW);
        glPopMatrix();
}


// cleanup routine after the main loop
void CleanUp()
{
        DEL_PTR(traverser);
        DEL_PTR(sceneQuery);
        DEL_PTR(bvh);
        DEL_PTR(visualization);
        DEL_PTR(camera);
        DEL_PTR(loader);
        DEL_PTR(renderQueue);
        DEL_PTR(perfGraph);

        DEL_PTR(fbo);
        DEL_PTR(ssaoShader);

        if (sCgMrtVertexProgram)
                cgDestroyProgram(sCgMrtVertexProgram);
        if (RenderState::sCgMrtFragmentProgram)
                cgDestroyProgram(RenderState::sCgMrtFragmentProgram);
        if (RenderState::sCgMrtFragmentTexProgram)
                cgDestroyProgram(RenderState::sCgMrtFragmentTexProgram);
        
        if (sCgContext)
                cgDestroyContext(sCgContext);
}


// this function inserts a dezimal point after each 1000
void CalcDecimalPoint(string &str, int d, int len)
{
        static vector<int> numbers;
        numbers.clear();

        static string shortStr;
        shortStr.clear();

        static char hstr[100];

        while (d != 0)
        {
                numbers.push_back(d % 1000);
                d /= 1000;
        }

        // first element without leading zeros
        if (numbers.size() > 0)
        {
                sprintf(hstr, "%d", numbers.back());
                shortStr.append(hstr);
        }
        
        for (int i = (int)numbers.size() - 2; i >= 0; i--)
        {
                sprintf(hstr, ",%03d", numbers[i]);
                shortStr.append(hstr);
        }

        int dif = len - (int)shortStr.size();

        for (int i = 0; i < dif; ++ i)
        {
                str += " ";
        }

        str.append(shortStr);
}


void DisplayStats()
{
        static char msg[9][300];

        static double frameTime = elapsedTime;
        static double renderTime = algTime;

        const float expFactor = 0.1f;

        // if some strange render time spike happened in this frame => don't count
        if (elapsedTime < 500) frameTime = elapsedTime * expFactor + (1.0f - expFactor) * elapsedTime;
        
        static float rTime = 1000.0f;

        if (showAlgorithmTime)
        {
                if (algTime < 500) renderTime = algTime * expFactor + (1.0f - expFactor) * renderTime;
        }

        accumulatedTime += elapsedTime;

        if (accumulatedTime > 500) // update every fraction of a second
        {       
                accumulatedTime = 0;

                if (frameTime) fps = 1e3f / (float)frameTime;

                rTime = renderTime;

                if (renderLightView && shadowTraverser)
                {
                        renderedTriangles = shadowTraverser->GetStats().mNumRenderedTriangles;
                        renderedObjects = shadowTraverser->GetStats().mNumRenderedGeometry;
                        renderedNodes = shadowTraverser->GetStats().mNumRenderedNodes;
                }
                else if (showShadowMap && shadowTraverser)
                {
                        renderedNodes = traverser->GetStats().mNumRenderedNodes + shadowTraverser->GetStats().mNumRenderedNodes;
                        renderedObjects = traverser->GetStats().mNumRenderedGeometry + shadowTraverser->GetStats().mNumRenderedGeometry;
                        renderedTriangles = traverser->GetStats().mNumRenderedTriangles + shadowTraverser->GetStats().mNumRenderedTriangles;
                }
                else
                {
                        renderedTriangles = traverser->GetStats().mNumRenderedTriangles;
                        renderedObjects = traverser->GetStats().mNumRenderedGeometry;
                        renderedNodes = traverser->GetStats().mNumRenderedNodes;
                }

                traversedNodes = traverser->GetStats().mNumTraversedNodes;
                frustumCulledNodes = traverser->GetStats().mNumFrustumCulledNodes;
                queryCulledNodes = traverser->GetStats().mNumQueryCulledNodes;
                issuedQueries = traverser->GetStats().mNumIssuedQueries;
                stateChanges = traverser->GetStats().mNumStateChanges;
                numBatches = traverser->GetStats().mNumBatches;
        }


        Begin2D();

        glEnable(GL_BLEND);
        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

        if (showHelp)
        {       
                DrawHelpMessage();
        }
        else
        {
                if (showOptions)
                {
                        glColor4f(0.0f, 0.0f, 0.0f, 0.5f);
                        glRecti(5, winHeight - 95, winWidth * 2 / 3 - 5, winHeight - 5);
                }

                if (showStatistics)
                {
                        glColor4f(0.0f, 0.0f, 0.0f, 0.5f);
                        glRecti(5, winHeight - 165, winWidth * 2 / 3 - 5, winHeight - 100);
                }

                glEnable(GL_TEXTURE_2D);

                myfont.Begin();

                if (showOptions)
                {
                        glColor3f(0.0f, 1.0f, 0.0f);

                        int i = 0;

                        static char *renderMethodStr[] = {"forward", "depth pass + forward", "deferred shading", "depth pass + deferred"};
        
                        sprintf(msg[i ++], "multiqueries: %d, tight bounds: %d, render queue: %d", 
                                                        useMultiQueries, useTightBounds, useRenderQueue);

                        sprintf(msg[i ++], "render technique: %s, SSAO: %d", renderMethodStr[renderMethod], useAdvancedShading);

                        sprintf(msg[i ++], "triangles per virtual leaf: %5d", trianglesPerVirtualLeaf);

                        sprintf(msg[i ++], "assumed visible frames: %4d, max batch size: %4d", 
                                assumedVisibleFrames, maxBatchSize);

                        for (int j = 0; j < 4; ++ j)
                                myfont.DrawString(msg[j], 10.0f, winHeight - 5 - j * 20);
                }

                if (showStatistics)
                {
                        glColor3f(1.0f, 1.0f, 0.0f);

                        string objStr, totalObjStr;
                        string triStr, totalTriStr;

                        int len = 10;
                        CalcDecimalPoint(objStr, renderedObjects, len);
                        CalcDecimalPoint(totalObjStr, (int)loader->GetNumEntities(), len);

                        CalcDecimalPoint(triStr, renderedTriangles, len);
                        CalcDecimalPoint(totalTriStr, bvh->GetBvhStats().mTriangles, len);

                        int i = 4;

                        if (0)
                        {
                                sprintf(msg[i ++], "rendered: %s of %s objects, %s of %s triangles", 
                                        objStr.c_str(), totalObjStr.c_str(), triStr.c_str(), totalTriStr.c_str()); 
                        }
                        else
                        {
                                sprintf(msg[i ++], "rendered: %6d of %6d nodes, %s of %s triangles", 
                                        renderedNodes, bvh->GetNumVirtualNodes(), triStr.c_str(), totalTriStr.c_str()); 
                        }

                        sprintf(msg[i ++], "traversed: %5d, frustum culled: %5d, query culled: %5d",
                                traversedNodes, frustumCulledNodes, queryCulledNodes);

                        sprintf(msg[i ++], "issued queries: %5d, state changes: %5d, render batches: %5d", 
                                issuedQueries, stateChanges, numBatches);

                        for (int j = 4; j < 7; ++ j)
                                myfont.DrawString(msg[j], 10.0f, winHeight - (j + 1) * 20);
                }

                glColor3f(1.0f, 1.0f, 1.0f);
                static char *alg_str[] = {"Frustum Cull", "Stop and Wait", "CHC", "CHC ++"};
                
                if (!showAlgorithmTime)
                                sprintf(msg[7], "%s:  %6.1f fps", alg_str[renderMode], fps);
                else
                        sprintf(msg[7], "%s:  %6.1f ms", alg_str[renderMode], rTime);
                
                myfont.DrawString(msg[7], 1.3f, 690.0f, 760.0f);//, top_color, bottom_color);
                
                //sprintf(msg[8], "algorithm time: %6.1f ms", rTime);
                //myfont.DrawString(msg[8], 720.0f, 730.0f);            
        }

        glDisable(GL_BLEND);
        glDisable(GL_TEXTURE_2D);

        End2D();
}       


void RenderSky()
{
        cgGLEnableProfile(RenderState::sCgVertexProfile);

        if ((renderMethod == RENDER_DEFERRED) || (renderMethod == RENDER_DEPTH_PASS_DEFERRED))
                state.SetRenderPassType(RenderState::DEFERRED);

        const bool useToneMapping = ((renderMethod == RENDER_DEPTH_PASS_DEFERRED) || (renderMethod == RENDER_DEFERRED)) && useHDR;

        preetham->RenderSkyDome(-light->GetDirection(), camera, &state, !useToneMapping);

        cgGLDisableProfile(RenderState::sCgVertexProfile);
        cgGLDisableProfile(RenderState::sCgFragmentProfile);
}


// render visible object from depth pass
void RenderVisibleObjects()
{
        if (renderMethod == RENDER_DEPTH_PASS_DEFERRED)
        {
                if (showShadowMap && !renderLightView)
                {
                        float minVisibleDist = min(camera->GetFar(), traverser->GetMaxVisibleDistance());
                        RenderShadowMap(minVisibleDist);
                }

                glDisable(GL_LIGHTING);
                glViewport(0, 0, texWidth, texHeight);

                InitDeferredRendering();
        }
        else
        {
                glEnable(GL_LIGHTING);
                state.SetRenderPassType(RenderState::FIXED);
        }

        glShadeModel(GL_SMOOTH);
        glEnableClientState(GL_NORMAL_ARRAY);

        // draw all objects that have exactly the same depth as the current sample
        glDepthFunc(GL_LEQUAL);
        glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);

        glClear(GL_COLOR_BUFFER_BIT);

        state.SetUseAlphaToCoverage(true);
        state.Reset();

        //cout << "visible: " << (int)traverser->GetVisibleObjects().size() << endl;

        SceneEntityContainer::const_iterator sit, 
                sit_end = traverser->GetVisibleObjects().end();

        for (sit = traverser->GetVisibleObjects().begin(); sit != sit_end; ++ sit)
        {
                renderQueue->Enqueue(*sit);
        }

        renderQueue->Apply();

        glDepthFunc(GL_LESS);
        state.Reset();

        PrintGLerror("visibleobjects");
}


void PlaceViewer(const Vector3 &oldPos)
{
        Vector3 playerPos = camera->GetPosition();
        bool validIntersect = sceneQuery->CalcIntersection(playerPos);

        if (validIntersect) 
                // && ((playerPos.z - oldPos.z) < bvh->GetBox().Size(2) * 1e-1f))
        {
                camera->SetPosition(playerPos);
        }
}


void RenderShadowMap(float newfar)
{
        cgGLDisableProfile(RenderState::sCgFragmentProfile);
        cgGLDisableProfile(RenderState::sCgVertexProfile);

        glDisableClientState(GL_NORMAL_ARRAY);

        state.SetRenderPassType(RenderState::DEPTH_PASS);
        state.LockCullFaceEnabled(true);
        state.SetUseAlphaToCoverage(false);

        // change CHC++ set of state variables 
        // this must be done for each change of camera because
        // otherwise the temporal coherency is broken
        BvhNode::SetCurrentState(1);

        // hack: temporarily change camera far plane
        camera->SetFar(newfar);
        glDisable(GL_CULL_FACE);
        
        // the scene is rendered withouth any shading   
        shadowMap->ComputeShadowMap(shadowTraverser, viewProjMat);

        glEnable(GL_CULL_FACE);
        camera->SetFar(farDist);

        state.SetUseAlphaToCoverage(true);
        state.LockCullFaceEnabled(false);

        glEnableClientState(GL_NORMAL_ARRAY);

        // change back state
        BvhNode::SetCurrentState(0);
}