source: GTP/trunk/App/Demos/Vis/FriendlyCulling/src/chcdemo.cpp @ 3252

// chcdemo.cpp : Defines the entry point for the console application.
//


#include "common.h"

#ifdef _CRT_SET
        #define _CRTDBG_MAP_ALLOC
        #include <stdlib.h>
        #include <crtdbg.h>

        // redefine new operator
        #define DEBUG_NEW new(_NORMAL_BLOCK, __FILE__, __LINE__)
        #define new DEBUG_NEW
#endif

#include <math.h>
#include <time.h>
#include "glInterface.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 "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 "SkyPreetham.h"
#include "Texture.h"
#include "ShaderManager.h"
#include "MotionPath.h"
#include "ShaderProgram.h"
#include "Shape.h"
#include "WalkThroughRecorder.h"
#include "StatsWriter.h"
#include "VisibilitySolutionLoader.h"
#include "ViewCellsTree.h"


using namespace std;
using namespace CHCDemoEngine;


/// the environment for the program parameter
static Environment env;


GLuint fontTex;
/// the fbo used for MRT
FrameBufferObject *fbo = NULL;
/// the renderable scene geometry
SceneEntityContainer sceneEntities;
/// the dynamic objects in the scene
SceneEntityContainer dynamicObjects;
// traverses and renders the hierarchy
RenderTraverser *traverser = NULL;
/// the hierarchy
Bvh *bvh = NULL;
/// handles scene loading
ResourceManager *resourceManager = NULL;
/// handles scene loading
ShaderManager *shaderManager = NULL;
/// the scene camera
PerspectiveCamera *camera = NULL;
/// the scene camera
PerspectiveCamera *visCamera = NULL;
/// the visualization
Visualization *visualization = NULL;
/// the current render renderState
RenderState renderState;
/// the rendering algorithm
int renderMode = RenderTraverser::CHCPLUSPLUS;
/// eye near plane distance
const float nearDist = 0.2f;
//const float nearDist = 1.0f;
/// eye far plane distance
float farDist = 1e6f;
/// the field of view
const float fov = 50.0f;

SceneQuery *sceneQuery = NULL;
RenderQueue *renderQueue = NULL;
/// traverses and renders the hierarchy
RenderTraverser *shadowTraverser = NULL;
/// the skylight + skydome model
SkyPreetham *preetham = NULL;

MotionPath *motionPath = NULL;
/// max depth where candidates for tighter bounds are searched
int maxDepthForTestingChildren = 3;
/// use full resolution for ssao or half
bool ssaoUseFullResolution = false;

/// store the frames as tga
bool recordFrames = false;
/// record the taken path
bool recordPath = false;
/// replays the recorded path
bool replayPath = false;
/// frame number for replay
int currentReplayFrame = -1;

string recordedFramesSuffix("frames");
string statsFilename("stats");

string filename("city");
string visibilitySolution("");


/// the walkThroughRecorder
WalkThroughRecorder *walkThroughRecorder = NULL;
WalkThroughPlayer *walkThroughPlayer = NULL;
StatsWriter *statsWriter = NULL;

bool makeSnapShot = false;

ViewCellsTree *viewCellsTree = NULL;
ViewCell *viewCell = NULL;

bool useSkylightForIllum = true;

static int globalVisibleId = 0;



/// the technique used for rendering
enum RenderTechnique
{
        FORWARD,
        DEFERRED,
        DEPTH_PASS
};


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

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

static int winWidth = 1024;
static int winHeight = 768;
static float winAspectRatio = 1.0f;

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

/// elapsed time in milliseconds
double elapsedTime = 1000.0;
double algTime = 1000.0;
double accumulatedTime = 1000.0;
float fps = 1e3f;
float turbitity = 5.0f;

// ssao parameters
float ssaoKernelRadius = 1e-8f;
float ssaoSampleIntensity = 0.2f;
float ssaoFilterRadius = 12.0f;
float ssaoTempCohFactor = 255.0;
bool sortSamples = true;

int shadowSize = 2048;

/// the hud font
glfont::GLFont myfont;

// rendertexture
int texWidth = 1024;
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 renderState
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 leftStrafeKeyPressed = false;
bool rightStrafeKeyPressed = false;

bool altKeyPressed = 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 useHDR = true;
bool useAntiAliasing = true;
bool useLenseFlare = true;

bool usePvs = false;


PerfTimer frameTimer, algTimer;
/// the performance graph window
PerformanceGraph *perfGraph = NULL;

int sCurrentMrtSet = 0;

static Matrix4x4 invTrafo = IdentityMatrix();

float mouseMotion = 0.2f;


//////////////
//-- chc++ algorithm parameters

/// the pixel threshold where a node is still considered invisible 
/// (should be zero for conservative visibility)
int threshold;
int assumedVisibleFrames = 10;
int maxBatchSize = 50;
int trianglesPerVirtualLeaf = INITIAL_TRIANGLES_PER_VIRTUAL_LEAVES;


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

enum {CAMERA_PASS = 0, LIGHT_PASS = 1};


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

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


SceneEntity *buddha = NULL;
SceneEntity *skyDome = NULL;
SceneEntity *sunBox = NULL;

GLuint sunQuery = 0;


////////////////////
//--- function forward declarations

void InitExtensions();
void InitGLstate();

void DisplayVisualization();
/// destroys all allocated resources
void CleanUp();
void SetupEyeView();
void SetupLighting();
void DisplayStats();
/// draw the help screen
void DrawHelpMessage();
/// render the sky dome
void RenderSky();
/// render the objects found visible in the depth pass
void RenderVisibleObjects();

int TestSunVisible();

void Begin2D();
void End2D();
/// the main loop
void MainLoop();

void KeyBoard(unsigned char c, int x, int y);
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 renderState, int x, int y);
void LeftMotion(int x, int y);
void RightMotion(int x, int y);
void MiddleMotion(int x, int y);
void KeyHorizontalMotion(float shift);
void KeyVerticalMotion(float shift);
/// returns the string representation of a number with the decimal points
void CalcDecimalPoint(string &str, int d);
/// Creates the traversal method (vfc, stopandwait, chc, chc++)
RenderTraverser *CreateTraverser(PerspectiveCamera *cam);
/// place the viewer on the floor plane
void PlaceViewer(const Vector3 &oldPos);
// initialise the frame buffer objects
void InitFBO();
/// changes the sunlight direction
void RightMotionLight(int x, int y);
/// render the shader map
void RenderShadowMap(float newfar);
/// function that touches each material once in order to accelarate render queue
void PrepareRenderQueue();
/// loads the specified model
int LoadModel(const string &model, SceneEntityContainer &entities);

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

void CreateAnimation();

SceneQuery *GetOrCreateSceneQuery();

void LoadPvs();

void LoadVisibilitySolution();

void RenderViewCell();


// new view projection matrix of the camera
static Matrix4x4 viewProjMat = IdentityMatrix();
// the old view projection matrix of the camera
static Matrix4x4 oldViewProjMat = IdentityMatrix();



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[])
{
#ifdef _CRT_SET
        //Now just call this function at the start of your program and if you're
        //compiling in debug mode (F5), any leaks will be displayed in the Output
        //window when the program shuts down. If you're not in debug mode this will
        //be ignored. Use it as you will!
        //note: from GDNet Direct [3.8.04 - 3.14.04] void detectMemoryLeaks() {

        _CrtSetDbgFlag(_CRTDBG_LEAK_CHECK_DF|_CRTDBG_ALLOC_MEM_DF);
        _CrtSetReportMode(_CRT_ASSERT,_CRTDBG_MODE_FILE);
        _CrtSetReportFile(_CRT_ASSERT,_CRTDBG_FILE_STDERR); 
#endif


        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;

        const 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.GetIntParam(string("winWidth"), winWidth);
                env.GetIntParam(string("winHeight"), winHeight);
                env.GetIntParam(string("shadowSize"), shadowSize);
                env.GetIntParam(string("maxDepthForTestingChildren"), maxDepthForTestingChildren);

                env.GetFloatParam(string("keyForwardMotion"), keyForwardMotion);
                env.GetFloatParam(string("keyRotation"), keyRotation);
                env.GetFloatParam(string("mouseMotion"), mouseMotion);
                env.GetFloatParam(string("tempCohFactor"), ssaoTempCohFactor);
                env.GetFloatParam(string("turbitity"), turbitity);
                
                env.GetVectorParam(string("camPosition"), camPos);
                env.GetVectorParam(string("camDirection"), camDir);
                env.GetVectorParam(string("lightDirection"), lightDir);

                env.GetBoolParam(string("useFullScreen"), useFullScreen);
                env.GetBoolParam(string("useLODs"), useLODs);
                env.GetBoolParam(string("useHDR"), useHDR);
                env.GetBoolParam(string("useAA"), useAntiAliasing);
                env.GetBoolParam(string("useLenseFlare"), useLenseFlare);
                env.GetBoolParam(string("useAdvancedShading"), useAdvancedShading);

                env.GetIntParam(string("renderMethod"), renderMethod);

                env.GetFloatParam(string("ssaoKernelRadius"), ssaoKernelRadius);
                env.GetFloatParam(string("ssaoSampleIntensity"), ssaoSampleIntensity);
                env.GetBoolParam(string("ssaoUseFullResolution"), ssaoUseFullResolution);

                env.GetStringParam(string("recordedFramesSuffix"), recordedFramesSuffix);
                env.GetStringParam(string("statsFilename"), statsFilename);
                env.GetStringParam(string("filename"), filename);
                env.GetStringParam(string("visibilitySolution"), visibilitySolution);

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

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

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

                texWidth = winWidth;
                texHeight = winHeight;

                cout << "assumed visible frames: " << assumedVisibleFrames << endl; 
                cout << "max batch size: " << maxBatchSize << endl;
                cout << "triangles per virtual leaf: " << trianglesPerVirtualLeaf << endl;

                cout << "key forward motion: " << keyForwardMotion << endl;
                cout << "key rotation: " << keyRotation << endl;
                cout << "win width: " << winWidth << endl;
                cout << "win height: " << winHeight << endl;
                cout << "use full screen: " << useFullScreen << endl;
                cout << "use LODs: " << useLODs << endl;
                cout << "camera position: " << camPos << endl;
                cout << "shadow size: " << shadowSize << endl;
                cout << "render method: " << renderMethod << endl;
                cout << "use antialiasing: " << useAntiAliasing << endl;
                cout << "use lense flare: " << useLenseFlare << endl;
                cout << "use advanced shading: " << useAdvancedShading << endl;
                cout << "turbitity: " << turbitity << endl;
                cout << "temporal coherence factor: " << ssaoTempCohFactor << endl;
                cout << "sample intensity: " << ssaoSampleIntensity << endl;
                cout << "kernel radius: " << ssaoKernelRadius << endl;
                cout << "use ssao full resolution: " << ssaoUseFullResolution << endl;
                cout << "recorded frames suffix: " << recordedFramesSuffix << endl;
                cout << "stats filename: " << statsFilename << endl;
                cout << "static scene filename prefix: " << filename << endl;
                cout << "use PVSs: " << usePvs << endl;
                cout << "visibility solution: " << visibilitySolution << endl;
                cout << "use skylight for illumination: " << useSkylightForIllum << endl;

                //cout << "model path: " << model_path << endl;
                cout << "**** end parameters ****" << endl << endl;
        }

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

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

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

        visCamera = new PerspectiveCamera(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));
        // the render queue for material sorting
        renderQueue = new RenderQueue(&renderState);

        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(MainLoop);
        glutKeyboardFunc(KeyBoard);
        glutSpecialFunc(Special);
        glutReshapeFunc(Reshape);
        glutMouseFunc(Mouse);
        glutIdleFunc(MainLoop);
        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);

        resourceManager = ResourceManager::GetSingleton();
        shaderManager = ShaderManager::GetSingleton();


        ///////////
        //-- load the static scene geometry

        LoadModel(filename + ".dem", sceneEntities);


        //////////
        //-- load some dynamic stuff

        //resourceManager->mUseNormalMapping = true;
        //resourceManager->mUseNormalMapping = false;

        resourceManager->mUseSpecialColors = true;

        //LoadModel("fisch.dem", dynamicObjects);

        //LoadModel("venusm.dem", dynamicObjects);
        //LoadModel("camel.dem", dynamicObjects);
        //LoadModel("toyplane2.dem", dynamicObjects);
        //LoadModel("elephal.dem", dynamicObjects);
        //LoadModel("sibenik.dem", dynamicObjects);

#if 0
        LoadModel("hbuddha.dem", dynamicObjects);

        buddha = dynamicObjects.back();
        
        const Vector3 sceneCenter(470.398f, 240.364f, 181.7f);
        //const Vector3 sceneCenter(470.398f, 240.364f, 180.3);
        
        Matrix4x4 transl = TranslationMatrix(sceneCenter);
        buddha->GetTransform()->SetMatrix(transl);

        for (int i = 0; i < 10; ++ i)
        {
                SceneEntity *ent = new SceneEntity(*buddha);
                resourceManager->AddSceneEntity(ent);

                Vector3 offs = Vector3::ZERO();

                offs.x = RandomValue(.0f, 50.0f);
                offs.y = RandomValue(.0f, 50.0f);

                Vector3 newPos = sceneCenter + offs;

                transl = TranslationMatrix(newPos);
                Transform3 *transform = resourceManager->CreateTransform(transl);

                ent->SetTransform(transform);
                dynamicObjects.push_back(ent);
        }
#endif

        
        resourceManager->mUseNormalMapping = false;
        resourceManager->mUseSpecialColors = false;


        ///////////
        //-- load the associated static bvh

        const string bvh_filename = string(model_path + filename + ".bvh");

        BvhLoader bvhLoader;
        bvh = bvhLoader.Load(bvh_filename, sceneEntities, dynamicObjects, maxDepthForTestingChildren);

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

        /// set the depth of the bvh depending on the triangles per leaf node
        bvh->SetVirtualLeaves(trianglesPerVirtualLeaf);

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


        //////////////////
        //-- setup the skydome model

        LoadModel("sky.dem", sceneEntities);
        skyDome = sceneEntities.back();

        /// the turbitity of the sky (from clear to hazy, use <3 for clear sky)
        preetham = new SkyPreetham(turbitity, skyDome);

        CreateAnimation();


        //////////////////////////
        //-- a bounding box representing the sun pos in order to test visibility

        Transform3 *trafo = resourceManager->CreateTransform(IdentityMatrix());

        // make it slightly bigger to simulate sun diameter
        const float size = 25.0f;
        AxisAlignedBox3 sbox(Vector3(-size), Vector3(size));

        SceneEntityConverter conv;


        //////////////////
        //-- occlusion query for sun

        // todo: clean up material
        Material *mat = resourceManager->CreateMaterial();

        mat->GetTechnique(0)->SetDepthWriteEnabled(false);
        mat->GetTechnique(0)->SetColorWriteEnabled(false);

        sunBox = conv.ConvertBox(sbox, mat, trafo);
        resourceManager->AddSceneEntity(sunBox);

        /// create single occlusion query that handles sun visibility
        glGenQueriesARB(1, &sunQuery);


        //////////
        //-- initialize the traversal algorithm

        traverser = CreateTraverser(camera);
        
        // the bird-eye visualization
        visualization = new Visualization(bvh, camera, NULL, &renderState);

        // this function assign the render queue bucket ids of the materials in beforehand
        // => probably less overhead for new parts of the scene that are not yet assigned
        PrepareRenderQueue();
        /// forward rendering is the default
        renderState.SetRenderTechnique(FORWARD);
        // frame time is restarted every frame
        frameTimer.Start();

        //Halton::TestHalton(7, 2);
        //HaltonSequence::TestHalton(15, 2);
        //Halton::TestPrime();

        // the rendering loop
        glutMainLoop();
        
        // clean up
        CleanUp();
        
        return 0;
}


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

        // this fbo basicly stores the scene information we get from standard rendering of a frame
        // we store diffuse colors, eye space depth and normals
        fbo = new FrameBufferObject(texWidth, texHeight, FrameBufferObject::DEPTH_32);

        // the diffuse color buffer
        fbo->AddColorBuffer(ColorBufferObject::RGBA_FLOAT_32, ColorBufferObject::WRAP_CLAMP_TO_EDGE, ColorBufferObject::FILTER_LINEAR, ColorBufferObject::FILTER_NEAREST);
        // the normals buffer
        //fbo->AddColorBuffer(ColorBufferObject::RGB_FLOAT_16, ColorBufferObject::WRAP_CLAMP_TO_EDGE, ColorBufferObject::FILTER_NEAREST);
        fbo->AddColorBuffer(ColorBufferObject::RGB_FLOAT_16, ColorBufferObject::WRAP_CLAMP_TO_EDGE, ColorBufferObject::FILTER_LINEAR);
        // a rgb buffer which could hold material properties
        //fbo->AddColorBuffer(ColorBufferObject::RGB_UBYTE, ColorBufferObject::WRAP_CLAMP_TO_EDGE, ColorBufferObject::FILTER_NEAREST);
        // buffer holding the difference vector to the old frame
        fbo->AddColorBuffer(ColorBufferObject::RGB_FLOAT_16, ColorBufferObject::WRAP_CLAMP_TO_EDGE, ColorBufferObject::FILTER_LINEAR);
        // another color buffer
        fbo->AddColorBuffer(ColorBufferObject::RGBA_FLOAT_32, ColorBufferObject::WRAP_CLAMP_TO_EDGE, ColorBufferObject::FILTER_LINEAR, ColorBufferObject::FILTER_NEAREST);

        for (int i = 0; i < 4; ++ i)
        {
                FrameBufferObject::InitBuffer(fbo, i);
        }

        PrintGLerror("init 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, 1e20f);
        
        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(PerspectiveCamera *cam)
{
        RenderTraverser *tr;
        
        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(&renderState);
        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);
        tr->SetShowBounds(showBoundingVolumes);

        bvh->ResetNodeClassifications();


        return tr;
}

/** Setup sunlight
*/
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 useHDRValues = 
                ((renderMethod == RENDER_DEPTH_PASS_DEFERRED) || 
                 (renderMethod == RENDER_DEFERRED)) && useHDR;


        Vector3 sunAmbient;
        Vector3 sunDiffuse;

        if (useSkylightForIllum)
        {
                preetham->ComputeSunColor(lightDir, sunAmbient, sunDiffuse, !useHDRValues);

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

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

                ambient[0] = .2f;
                ambient[1] = .2f;
                ambient[2] = .2f;

                diffuse[0] = 1.0f;
                diffuse[1] = 1.0f;
                diffuse[2] = 1.0f;
        }

        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;

        camera->SetupViewProjection();


        /////////////////
        //-- compute view projection matrix and store for later use

        Matrix4x4 matViewing, matProjection;

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

        viewProjMat = matViewing * matProjection;
}


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);
}


void KeyStrafe(float shift)
{
        Vector3 viewDir = camera->GetDirection();
        Vector3 pos = camera->GetPosition();

        // the 90 degree rotated view vector 
        // z 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 * shift;

        camera->SetPosition(pos);
}


/** Initialize the deferred rendering pass.
*/
void InitDeferredRendering()
{
        if (!fbo) InitFBO();
        fbo->Bind();

        // multisampling does not work with deferred shading
        glDisable(GL_MULTISAMPLE_ARB);
        renderState.SetRenderTechnique(DEFERRED);


        // draw to 3 render targets
        if (sCurrentMrtSet == 0)
        {
                DeferredRenderer::colorBufferIdx = 0;
                glDrawBuffers(3, mrt);
        }
        else 
        {
                DeferredRenderer::colorBufferIdx = 3;
                glDrawBuffers(3, mrt2);
        }

        sCurrentMrtSet = 1 - sCurrentMrtSet;
}


/** the main rendering loop
*/
void MainLoop() 
{       
        if (buddha)
        {
                Matrix4x4 oldTrafo = buddha->GetTransform()->GetMatrix();
                Vector3 buddhaPos = motionPath->GetCurrentPosition();
                Matrix4x4 trafo = TranslationMatrix(buddhaPos);

                buddha->GetTransform()->SetMatrix(trafo);

#if TODO // drop objects on ground floor
                for (int i = 0; i < 10; ++ i)
                {
                        SceneEntity *ent = dynamicObjects[i];
                        Vector3 newPos = ent->GetWorldCenter();

                        if (GetOrCreateSceneQuery()->CalcIntersection(newPos))
                        {
                                Matrix4x4 mat = TranslationMatrix(newPos - ent->GetCenter());
                                ent->GetTransform()->SetMatrix(mat);
                        }
                }
#endif

/*
                /////////////////////////
                //-- update animations

                //const float rotAngle = M_PI * 1e-3f;
                const float rotAngle = 1.0f * M_PI / 180.0f;

                Matrix4x4 rotMatrix = RotationZMatrix(rotAngle);
                dynamicObjects[2]->GetTransform()->MultMatrix(rotMatrix);

                motionPath->Move(0.01f);
                */
        }


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

        static Vector3 oldPos = camera->GetPosition();
        static Vector3 oldDir = camera->GetDirection();

        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());
        if (leftStrafeKeyPressed)
                KeyStrafe(KeyShift());
        if (rightStrafeKeyPressed)
                KeyStrafe(-KeyShift());


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

        if (showAlgorithmTime)
        {
                glFinish();
                algTimer.Start();
        }
        
        // don't allow replay on record
        if (replayPath && !recordPath)
        {
                if (!walkThroughPlayer)
                        walkThroughPlayer = new WalkThroughPlayer("frames.log");
                
                ++ currentReplayFrame;

                // reset if end of walkthrough is reached
                if (!walkThroughPlayer->ReadNextFrame(camera)) 
                {
                        currentReplayFrame = -1;
                        replayPath = false;
                }
        }

        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();
        
        // set frame related parameters for GPU programs
        GPUProgramParameters::InitFrame(camera, light);

        if (recordPath)
        {
                if (!walkThroughRecorder)
                        walkThroughRecorder = new WalkThroughRecorder("frames.log");
                
                if ((Distance(oldPos, camera->GetPosition()) > 1e-6f) ||
                        (DotProd(oldDir, camera->GetDirection()) < 1.0f - 1e-6f))
                {
                        walkThroughRecorder->WriteFrame(camera);
                }
        }

        // hack: store current rendering method and restore later
        int oldRenderMethod = renderMethod;
        // for rendering the light view, we use forward rendering
        if (renderLightView) renderMethod = FORWARD;

        /// enable vbo vertex array
        glEnableClientState(GL_VERTEX_ARRAY);

        if (1 && usePvs)
        {
                if (!viewCellsTree) LoadVisibilitySolution();
                LoadPvs();
        }

        // render with the specified method (forward rendering, forward + depth, deferred)
        switch (renderMethod)
        {
        case RENDER_FORWARD:
        
                glEnable(GL_MULTISAMPLE_ARB);
                renderState.SetRenderTechnique(FORWARD);
                
                glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
                glEnableClientState(GL_NORMAL_ARRAY);
                break;

        case RENDER_DEPTH_PASS_DEFERRED:

                glDisable(GL_MULTISAMPLE_ARB);
                renderState.SetUseAlphaToCoverage(false);
                renderState.SetRenderTechnique(DEPTH_PASS);

                if (!fbo) InitFBO(); 
                fbo->Bind();
                // render to single depth texture
                glDrawBuffers(1, mrt);
                // clear buffer once
                glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

                // the scene is rendered withouth any shading 
                // (should be handled by render renderState)
                glShadeModel(GL_FLAT);
                break;

        case RENDER_DEPTH_PASS:

                glEnable(GL_MULTISAMPLE_ARB);
                renderState.SetRenderTechnique(DEPTH_PASS);

                glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

                // the scene is rendered withouth any shading 
                // (should be handled by render renderState)
                glShadeModel(GL_FLAT);
                break;
        
        case RENDER_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);
                

        // set proper lod levels for current frame using current eye point
        LODLevel::InitFrame(camera->GetPosition());
        // set up sunlight
        SetupLighting();


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


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

        const bool useDeferred = 
                ((renderMethod == RENDER_DEFERRED) || (renderMethod == RENDER_DEPTH_PASS_DEFERRED));

        // if no lense flare => just set sun to invisible
        const int sunVisiblePixels = useLenseFlare  &&  useDeferred ? TestSunVisible() : 0;

        

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

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

        RenderSky();


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

        if (useDeferred)
        {
                FrameBufferObject::Release();

                if (!deferredShader) 
                {
                        deferredShader = 
                                new DeferredRenderer(texWidth, texHeight, camera, ssaoUseFullResolution);

                        deferredShader->SetKernelRadius(ssaoKernelRadius);
                        deferredShader->SetSampleIntensity(ssaoSampleIntensity);
                        deferredShader->SetSsaoFilterRadius(ssaoFilterRadius);
                }

                DeferredRenderer::SHADING_METHOD shadingMethod;

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

                static int snapShotIdx = 0;

                deferredShader->SetSunVisiblePixels(sunVisiblePixels);
                deferredShader->SetShadingMethod(shadingMethod);
                deferredShader->SetSamplingMethod(samplingMethod);
                
                deferredShader->SetUseTemporalCoherence(useTemporalCoherence);
                //deferredShader->SetSortSamples(sortSamples);
                deferredShader->SetTemporalCoherenceFactorForSsao(ssaoTempCohFactor);
                deferredShader->SetUseToneMapping(useHDR);
                deferredShader->SetUseAntiAliasing(useAntiAliasing);


                if (recordFrames && replayPath)
                        deferredShader->SetSaveFrame(recordedFramesSuffix, currentReplayFrame);
                else if (makeSnapShot)
                        deferredShader->SetSaveFrame("snap", snapShotIdx ++);           
                else
                        deferredShader->SetSaveFrame("", -1);           

                //if (makeSnapShot) makeSnapShot = false;

                ShadowMap *sm = showShadowMap ? shadowMap : NULL;
                deferredShader->Render(fbo, light, sm);
        }


        renderState.SetRenderTechnique(FORWARD);
        renderState.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);

        // statistics
        DisplayStats();

        glutSwapBuffers();

        oldPos = camera->GetPosition();
        oldDir = camera->GetDirection();
}


#pragma warning(disable : 4100)
void KeyBoard(unsigned char c, int x, int y) 
{
        switch(c) 
        {
        case 27:
                // write out current position on exit
                Debug << "camPosition=" << camera->GetPosition().x << " " << camera->GetPosition().y << " " << camera->GetPosition().z << endl;
                Debug << "camDirection=" << camera->GetDirection().x << " " << camera->GetDirection().y << " " << camera->GetDirection().z << endl;

                CleanUp();
                exit(0);
        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 *= 1.0f / 1.2f;
                cout << "new temporal coherence factor: " << ssaoTempCohFactor << endl;
                break;
        case '8':
                ssaoTempCohFactor *= 1.2f;
                cout << "new temporal coherence factor: " << ssaoTempCohFactor << endl;
                break;
        case '9':
                ssaoKernelRadius *= 0.8f;
                cout << "new ssao kernel radius: " << ssaoKernelRadius << endl;
                if (deferredShader) deferredShader->SetKernelRadius(ssaoKernelRadius);
                break;
        case '0':
                ssaoKernelRadius *= 1.0f / 0.8f;
                if (deferredShader) deferredShader->SetKernelRadius(ssaoKernelRadius);
                cout << "new ssao kernel radius: " << ssaoKernelRadius << endl;
                break;
        case 'n':
                ssaoSampleIntensity *= 0.9f;
                if (deferredShader) deferredShader->SetSampleIntensity(ssaoSampleIntensity);
                cout << "new ssao sample intensity: " << ssaoSampleIntensity << endl;
                break;
        case 'N':
                ssaoSampleIntensity *= 1.0f / 0.9f;
                if (deferredShader) deferredShader->SetSampleIntensity(ssaoSampleIntensity);
                cout << "new ssao sample intensity: " << ssaoSampleIntensity << endl;
                break;
        case 'o':
                ssaoFilterRadius *= 0.9f;
                if (deferredShader) deferredShader->SetSsaoFilterRadius(ssaoFilterRadius);
                cout << "new ssao filter radius: " << ssaoFilterRadius << endl;
                break;
        case 'O':
                ssaoFilterRadius *= 1.0f / 0.9f;
                if (deferredShader) deferredShader->SetSsaoFilterRadius(ssaoFilterRadius);
                cout << "new ssao filter radius: " << ssaoFilterRadius << endl;
                break;
        /*      case 'o':
        case 'O':
                useOptimization = !useOptimization;
                // chc optimization of using the objects instead of 
                // the bounding boxes for querying previously visible nodes
                traverser->SetUseOptimization(useOptimization);
                break;*/
        case 'l':
        case 'L':
                useLODs = !useLODs;
                SceneEntity::SetUseLODs(useLODs);
                cout << "using LODs: " << useLODs << endl;
                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 '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 'j':
        case 'J':
                leftStrafeKeyPressed = true;
                break;
        case 'k':
        case 'K':
                rightStrafeKeyPressed = true;
                break;
        case 'r':
        case 'R':
                useRenderQueue = !useRenderQueue;
                traverser->SetUseRenderQueue(useRenderQueue);
                break;
        case 'b':
        case 'B':
                useTightBounds = !useTightBounds;
                traverser->SetUseTightBounds(useTightBounds);
                break;
        case 'v':
        case 'V':
                renderLightView = !renderLightView;
                break;
        case 'h':
        case 'H':
                useHDR = !useHDR;
                break;
        case 'i':
        case 'I':
                useAntiAliasing = !useAntiAliasing;
                break;
        case 'c':
        case 'C':
                useLenseFlare = !useLenseFlare;
                break;
        case 'u':
        case 'U':
                // move light source instead of camera tilt
                moveLight = !moveLight;
                break;
        case '#':
                // make a snapshot of the current frame
                makeSnapShot = true;
                break;
        case '.':
                // enable / disable view cells
                usePvs = !usePvs;
                if (!usePvs) SceneEntity::SetGlobalVisibleId(-1);
                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;
        case 'j':
        case 'J':
                leftStrafeKeyPressed = false;
                break;
        case 'k':
        case 'K':
                rightStrafeKeyPressed = 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:
                replayPath = !replayPath;

                if (replayPath)
                {
                        cout << "replaying path" << endl;
                        currentReplayFrame = -1;
                }
                else
                {
                        cout << "finished replaying path" << endl;
                }

                break;
        case GLUT_KEY_F11:
                recordPath = !recordPath;
                
                if (recordPath)
                {
                        cout << "recording path" << endl;
                }
                else
                {
                        cout << "finished recording path" << endl;
                        // start over with new frame recording next time
                        DEL_PTR(walkThroughRecorder);
                }

                break;
        case GLUT_KEY_F12:
                recordFrames = !recordFrames;

                if (recordFrames)
                        cout << "recording frames on replaying" << endl;
                else
                        cout << "finished recording frames on replaying" << endl;
                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 renderState, int x, int y) 
{
        if ((button == GLUT_LEFT_BUTTON) && (renderState == GLUT_DOWN))
        {
                xEyeBegin = x;
                yMotionBegin = y;

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

                if (!moveLight)
                        glutMotionFunc(RightMotion);
                else
                        glutMotionFunc(RightMotionLight);
        }
        else if ((button == GLUT_MIDDLE_BUTTON) && (renderState == 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) * mouseMotion;
        
        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) * mouseMotion;
        pos[2] += (verticalMotionBegin - y) * mouseMotion;

        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()
{
        // render current view cell
        if (usePvs) RenderViewCell();
        
        visualization->SetViewCell(usePvs ? viewCell : NULL);
        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(showShadowMap);

        
        // 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(renderQueue);
        DEL_PTR(perfGraph);
        DEL_PTR(fbo);
        DEL_PTR(deferredShader);
        DEL_PTR(light);
        DEL_PTR(visCamera);
        DEL_PTR(preetham);
        DEL_PTR(shadowMap);
        DEL_PTR(shadowTraverser);
        DEL_PTR(motionPath);
        DEL_PTR(walkThroughRecorder);
        DEL_PTR(walkThroughPlayer);
        DEL_PTR(statsWriter);
        DEL_PTR(viewCellsTree);

        ResourceManager::DelSingleton();
        ShaderManager::DelSingleton();

        resourceManager = NULL;
        shaderManager = NULL;
}


// 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;

        // the render time used up purely for the traversal algorithm using glfinish
        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;
        }


        ////////////////
        //-- record stats on walkthrough

        static float accTime = .0f;
        static float averageTime = .0f;

        if (currentReplayFrame > -1) 
        {
                accTime += frameTime;
                averageTime = accTime / (currentReplayFrame + 1);

                if (!statsWriter)
                        statsWriter = new StatsWriter(statsFilename);
                        
                FrameStats frameStats;
                frameStats.mFrame = currentReplayFrame;
                frameStats.mFPS = 1e3f / (float)frameTime;
                frameStats.mTime = frameTime;
                frameStats.mNodes = renderedNodes;
                frameStats.mObjects = renderedObjects;
                frameStats.mTriangles = renderedTriangles;

                statsWriter->WriteFrameStats(frameStats);
        }
        else if (statsWriter)
        {
                Debug << "average frame time " << averageTime << " for traversal algorithm " << renderMode << endl;

                // reset average frame time
                averageTime = accTime = .0f;

                DEL_PTR(statsWriter);
        }


        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, use pvss: %d", renderMethodStr[renderMethod], usePvs);
                        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)resourceManager->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()
{
        if ((renderMethod == RENDER_DEFERRED) || (renderMethod == RENDER_DEPTH_PASS_DEFERRED))
                renderState.SetRenderTechnique(DEFERRED);

        const bool useToneMapping = 
                ((renderMethod == RENDER_DEPTH_PASS_DEFERRED) || 
                 (renderMethod == RENDER_DEFERRED)) && useHDR;
        
        preetham->RenderSkyDome(-light->GetDirection(), camera, &renderState, !useToneMapping);

        /// once again reset the renderState just to make sure
        renderState.Reset();
}


// render visible object from depth pass
void RenderVisibleObjects()
{
        if (renderMethod == RENDER_DEPTH_PASS_DEFERRED)
        {
                if (showShadowMap && !renderLightView)
                {
                        // usethe maximal visible distance to focus shadow map
                        const float newFar = min(camera->GetFar(), traverser->GetMaxVisibleDistance());
                        RenderShadowMap(newFar);
                }
                // initialize deferred rendering
                InitDeferredRendering();
        }
        else
        {
                renderState.SetRenderTechnique(FORWARD);
        }


        /////////////////
        //-- reset gl renderState before the final visible objects pass

        renderState.Reset();

        glEnableClientState(GL_NORMAL_ARRAY);
        /// switch back to smooth shading
        glShadeModel(GL_SMOOTH);
        /// reset alpha to coverage flag
        renderState.SetUseAlphaToCoverage(true);
        // clear color
        glClear(GL_COLOR_BUFFER_BIT);
        
        // draw only objects having exactly the same depth as the current sample
        glDepthFunc(GL_EQUAL);

        //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);
        }
        /// now render out everything in one giant pass
        renderQueue->Apply();

        // switch back to standard depth func
        glDepthFunc(GL_LESS);
        renderState.Reset();

        PrintGLerror("visibleobjects");
}


SceneQuery *GetOrCreateSceneQuery()
{
        if (!sceneQuery)
                sceneQuery = new SceneQuery(bvh->GetBox(), traverser, &renderState);

        return sceneQuery;
}


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

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


void RenderShadowMap(float newfar)
{
        glDisableClientState(GL_NORMAL_ARRAY);
        renderState.SetRenderTechnique(DEPTH_PASS);
        
        // hack: disable cull face because of alpha textured balconies
        glDisable(GL_CULL_FACE);
        renderState.LockCullFaceEnabled(true);

        /// don't use alpha to coverage for the depth map (problems with fbo rendering)
        renderState.SetUseAlphaToCoverage(false);

        // change CHC++ set of renderState variables 
        // this must be done for each change of camera because
        // otherwise the temporal coherency is broken
        BvhNode::SetCurrentState(LIGHT_PASS);
        // hack: temporarily change camera far plane
        camera->SetFar(newfar);
        // the scene is rendered withouth any shading   
        shadowMap->ComputeShadowMap(shadowTraverser, viewProjMat);

        camera->SetFar(farDist);

        renderState.SetUseAlphaToCoverage(true);
        renderState.LockCullFaceEnabled(false);
        glEnable(GL_CULL_FACE);

        glEnableClientState(GL_NORMAL_ARRAY);
        // change back renderState
        BvhNode::SetCurrentState(CAMERA_PASS);
}


/** Touch each material once in order to preload the render queue 
        bucket id of each material
*/
void PrepareRenderQueue()
{
        for (int i = 0; i < 3; ++ i)
        {
                renderState.SetRenderTechnique(i);

                // fill all shapes into the render queue        once so we can establish the buckets
                ShapeContainer::const_iterator sit, sit_end = (*resourceManager->GetShapes()).end();

                for (sit = (*resourceManager->GetShapes()).begin(); sit != sit_end; ++ sit)
                {
                        static Transform3 dummy(IdentityMatrix());
                        renderQueue->Enqueue(*sit, NULL);
                }
        
                // just clear queue again
                renderQueue->Clear();
        }
}


int LoadModel(const string &model, SceneEntityContainer &entities)
{
        const string filename = string(model_path + model);

        int numEntities = 0;

        cout << "\nloading model " << filename << endl;

        if (numEntities = resourceManager->Load(filename, entities))
        {
                cout << "model " << filename << " successfully loaded" << endl;
        }
        else
        {
                cerr << "loading model " << filename << " failed" << endl;

                CleanUp();
                exit(0);
        }

        return numEntities;
}


void CreateAnimation()
{
        const float radius = 5.0f;
        const Vector3 center(480.398f, 268.364f, 181.3);

        VertexArray vertices;

        /*for (int i = 0; i < 360; ++ i)
        {
                float angle = (float)i * M_PI / 180.0f;

                Vector3 offs = Vector3(cos(angle) * radius, sin(angle) * radius, 0);
                vertices.push_back(center + offs);
        }*/

        for (int i = 0; i < 5; ++ i)
        {
                Vector3 offs = Vector3(i, 0, 0);
                vertices.push_back(center + offs);
        }

        
        for (int i = 0; i < 5; ++ i)
        {
                Vector3 offs = Vector3(4 -i, 0, 0);
                vertices.push_back(center + offs);
        }

        motionPath = new MotionPath(vertices);
}

/** This function returns the number of visible pixels of a
        bounding box representing the sun.
*/
int TestSunVisible()
{
        // assume sun is at a far away point along the light vector
        Vector3 sunPos = light->GetDirection() * -1e3f;
        sunPos += camera->GetPosition();

        sunBox->GetTransform()->SetMatrix(TranslationMatrix(sunPos));

        glBeginQueryARB(GL_SAMPLES_PASSED_ARB, sunQuery);

        sunBox->Render(&renderState);

        glEndQueryARB(GL_SAMPLES_PASSED_ARB);

        GLuint sampleCount;

        glGetQueryObjectuivARB(sunQuery, GL_QUERY_RESULT_ARB, &sampleCount);

        return sampleCount;
}


static Technique GetVizTechnique()
{
        Technique tech;
        tech.Init();

        tech.SetEmmisive(RgbaColor(1.0f, 1.0f, 1.0f, 1.0f));
        tech.SetDiffuse(RgbaColor(1.0f, 1.0f, 1.0f, 1.0f));
        tech.SetAmbient(RgbaColor(1.0f, 1.0f, 1.0f, 1.0f));

        return tech;
}


void LoadPvs()
{
        viewCell = viewCellsTree->GetViewCell(camera->GetPosition());

        int numTriangles = 0;

        SceneEntity::SetGlobalVisibleId(globalVisibleId);

        for (int i = 0; i < viewCell->mPvs.Size(); ++ i)
        {
                SceneEntity *ent = viewCell->mPvs.GetEntry(i);
                ent->SetVisibleId(globalVisibleId);
                //ent->Render(&renderState);

                numTriangles += ent->CountNumTriangles();
        }

        ++ globalVisibleId;
}


void LoadVisibilitySolution()
{
        ///////////
        //-- load the visibility solution

        const string vis_filename = 
                string(model_path + visibilitySolution + ".vis");

        VisibilitySolutionLoader visLoader;

        viewCellsTree = visLoader.Load(vis_filename, bvh);

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


void RenderViewCell()
{
        // render current view cell
        static Technique vcTechnique = GetVizTechnique();

        vcTechnique.Render(&renderState);
        Visualization::RenderBoxForViz(viewCell->GetBox());
}