source: GTP/trunk/Lib/Vis/Preprocessing/src/GlobalLinesRenderer.cpp @ 1968

#include "glInterface.h"
#include "GlobalLinesRenderer.h"
#include "common.h"
#include "RenderTexture.h"
#include "Preprocessor.h"
#include "GlRenderer.h"
#include "Exporter.h"
#include "ViewCellsManager.h"


// the devil library
#include <IL/il.h>
#include <IL/ilu.h>
#include <IL/ilut.h>

#include <Cg/cg.h>
#include <Cg/cgGL.h>

//#include <QtOpenGL>

namespace GtpVisibilityPreprocessor {


static CGcontext sCgContext = NULL;
static CGprogram sCgDepthPeelingProgram = NULL;
static CGprogram sCgPassThroughProgram = NULL;

static CGprofile sCgFragmentProfile;
static CGparameter sTextureParam;
static CGparameter sTexWidthParam; 
static CGparameter sStepSizeParam;

GlobalLinesRenderer *globalLinesRenderer = NULL;

static bool isDepth = true;

static void InitDevIl()
{
        ilInit();
        ILuint ImageName;
        ilGenImages(1, &ImageName);
        ilBindImage(ImageName);
        ilEnable(IL_FILE_OVERWRITE);

        //  ilRegisterFormat(IL_RGBA);
        //  ilRegisterType(IL_FLOAT);

        //  ilEnable(IL_ORIGIN_SET);
        //  ilOriginFunc(IL_ORIGIN_UPPER_LEFT);
}


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);
        }
}


void Reshape(int w, int h)
{
        if (h == 0) h = 1;

        glViewport(0, 0, w, h);

        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();

        //gluPerspective(60.0, (GLfloat)w/(GLfloat)h, 3, 5000.0);
        //gluPerspective(60.0, (GLfloat)w/(GLfloat)h, 0.5, 10.0);
        glOrtho(-1, 1, -1, 1, 0.5, 15);
}


void SetFrustum(const int sizeX, const int sizeY, 
                                const float nearPlane, const float farPlane)
{
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();

        glOrtho(-sizeX * 0.5, sizeX * 0.5, 
                        -sizeY * 0.5, sizeY * 0.5, 
                        nearPlane, farPlane);

        /*glOrtho(0, sizeX, 
                    0, sizeY , 
                        nearPlane, farPlane);*/
}

void Display()
{
        //globalLinesRenderer->DrawGeometry();
        //globalLinesRenderer->CastGlobalLines(Beam(), 0);
        globalLinesRenderer->DisplayBuffer(isDepth);
        PrintGLerror("display");

        glutSwapBuffers();
}


void Idle()
{
        glutPostRedisplay();
}


void Keyboard(unsigned char key, int x, int y)
{
        switch(key)
        {
        case '2':
                {
                        VssRayContainer rays;

                        ++ globalLinesRenderer->mMaxDepth;
                        globalLinesRenderer->ApplyDepthPeeling(rays);

                        cout << "max depth: " << globalLinesRenderer->mMaxDepth << endl;
                        CLEAR_CONTAINER(rays);
                        return;
                }
        case '1':
                {
                        VssRayContainer rays;

                        -- globalLinesRenderer->mMaxDepth;
                        cout << "max depth: " << globalLinesRenderer->mMaxDepth << endl;
                        
                        globalLinesRenderer->ApplyDepthPeeling(rays);
                        CLEAR_CONTAINER(rays);
                        return;
                }
        case '3':
                {
                        globalLinesRenderer->ExportDepthBuffer();
                        return;
                }
        case '4':
                {
                        globalLinesRenderer->ExportItemBuffer();
                        return;
                }
        case '8':
                {
                        isDepth = !isDepth;
                        return;
                }
        case '9':
                {
                        VssRayContainer rays;
                        globalLinesRenderer->ApplyDepthPeeling(rays);
                        VssRayContainer outRays;
                        VssRayContainer::const_iterator vit, vit_end = rays.end();

                        const float p = 8.0f / (float)rays.size();

                        for (vit = rays.begin(); vit != vit_end; ++ vit)
                        {
                                if (Random(1.0f) < p)
                                {
                                        outRays.push_back(*vit);
                                }
                        }

                        globalLinesRenderer->Visualize(rays);
                        CLEAR_CONTAINER(rays);
                        return;
                }
        case '0':
                {
                        VssRayContainer rays;
                        globalLinesRenderer->ApplyDepthPeeling(rays);
                        CLEAR_CONTAINER(rays);
                        return;
                }
        default:
                return;
        }
}


GlobalLinesRenderer::GlobalLinesRenderer(Preprocessor *preprocessor, 
                                                                                 const int texHeight,
                                                                                 const int texWidth,
                                                                                 const float eps,
                                                                                 const int maxDepth,
                                                                                 const bool sampleReverse):
mNewTexture(NULL), 
mOldTexture(NULL), 
mPreprocessor(preprocessor),
mTexHeight(mTexHeight),
mTexWidth(mTexWidth),
mEpsilon(eps),
mMaxDepth(maxDepth),
mSampleReverse(sampleReverse)
{
        mRenderer = new GlRenderer(mPreprocessor->mSceneGraph,
                                                           mPreprocessor->mViewCellsManager,
                                                           mPreprocessor->mKdTree);

}


GlobalLinesRenderer::GlobalLinesRenderer(Preprocessor *preprocessor):
mNewTexture(NULL), 
mOldTexture(NULL), 
mMaxDepth(40), 
mPreprocessor(preprocessor),
mTexHeight(128),
mTexWidth(128),
mEpsilon(0.0001),
mSampleReverse(true)
{
        mRenderer = new GlRenderer(mPreprocessor->mSceneGraph,
                                                           mPreprocessor->mViewCellsManager,
                                                           mPreprocessor->mKdTree);
}


void GlobalLinesRenderer::DisplayBuffer(const bool isDepth)
{
        if (!isDepth)
                mNewTexture->Bind();
        else
                mNewTexture->BindDepth();
        mNewTexture->EnableTextureTarget();
        
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        
        if (mNewTexture->IsRectangleTexture())
        {
                glBegin(GL_QUADS);
                glTexCoord2f(0, 0); glVertex3f(-1, -1, -0.5f);
                glTexCoord2f(mNewTexture->GetWidth(), 0); glVertex3f( 1, -1, -0.5f);
                glTexCoord2f(mNewTexture->GetWidth(), mNewTexture->GetHeight()); glVertex3f( 1,  1, -0.5f);
                glTexCoord2f(0, mNewTexture->GetHeight()); glVertex3f(-1, 1, -0.5f);
                glEnd();
        }
        else
        {
                glBegin(GL_QUADS);
                glTexCoord2f(0, 0); glVertex3f(-1, -1, -0.5f);
                glTexCoord2f(1, 0); glVertex3f( 1, -1, -0.5f);
                glTexCoord2f(1, 1); glVertex3f( 1,  1, -0.5f);
                glTexCoord2f(0, 1); glVertex3f(-1,  1, -0.5f);
                glEnd();
        }  

        mNewTexture->DisableTextureTarget();
        PrintGLerror("displaytexture");
}


GlobalLinesRenderer::~GlobalLinesRenderer()
{
        if (sCgDepthPeelingProgram)
                cgDestroyProgram(sCgDepthPeelingProgram);
        if (sCgContext)
                cgDestroyContext(sCgContext);

        // init the receiving buffers
        delete mNewDepthBuffer;
        delete mOldDepthBuffer;
        
        delete mNewItemBuffer;
        delete mOldItemBuffer;

        DEL_PTR(mRenderer);
}

 
void GlobalLinesRenderer::InitRenderTexture(RenderTexture *rt)
{
         // setup the rendering context for the RenderTexture
        rt->BeginCapture();
        {
                //Reshape(mTexWidth, mTexHeight);
                glViewport(0, 0, mTexWidth, mTexHeight);
                SetFrustum(mWidth, mWidth, mNear, mFar);

                // for item buffer: white means no color
                glClearColor(1, 1, 1, 1);
                glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

                glFrontFace(GL_CCW);
                glCullFace(GL_BACK);

                glDisable(GL_CULL_FACE);
                //glEnable(GL_CULL_FACE);

                glShadeModel(GL_FLAT);
                glEnable(GL_DEPTH_TEST);
                
                glMatrixMode(GL_MODELVIEW);
                glLoadIdentity();
                gluLookAt(mViewPoint.x, mViewPoint.y, mViewPoint.z, 
                                  mTermination.x, mTermination.y, mTermination.z, 
                                  mUpVec.x, mUpVec.y, mUpVec.z);

        }
        rt->EndCapture();
}


void GlobalLinesRenderer::InitScene(const float alpha, const float beta)
{
        AxisAlignedBox3 bbox = 
                globalLinesRenderer->mPreprocessor->mKdTree->GetBox();
        
        const float sceneSize = Magnitude(bbox.Diagonal());

        // compute the center of the scene
        mTermination = bbox.Center();
        
        // add a small offset to provide some randomness in the sampling
        if (0)
        {
                Vector3 offset(
                        Random(sceneSize * 1e-3f), 
                        Random(sceneSize * 1e-3f), 
                        Random(sceneSize * 1e-3f));

                mTermination += offset;
        }
                
        mNear = 1;
        mFar = sceneSize * 2;
        mWidth = sceneSize;

        ComputeLookAt(alpha, 
                                  beta,
                                  mEyeVec, 
                                  mUpVec,
                                  mLeftVec);
        
        mViewPoint = mTermination - 0.5f * sceneSize * mEyeVec;

        cout << "termination point: " << mTermination << endl;
        cout << "view point: " << mViewPoint << endl;
        cout << "scene: " << bbox << endl;

        InitRenderTexture(mNewTexture);
        InitRenderTexture(mOldTexture);
        
        cout << "eye: " << mEyeVec << " left: " << mLeftVec << " up: " << mUpVec << endl;
}


void GlobalLinesRenderer::InitScene(const SimpleRay &ray)
{
        AxisAlignedBox3 bbox = 
                globalLinesRenderer->mPreprocessor->mKdTree->GetBox();
        
        const float sceneSize = Magnitude(bbox.Diagonal());

        // compute the center of the scene
        mViewPoint = ray.mOrigin;
        mTermination = ray.mOrigin + ray.mDirection;

        mEyeVec = Normalize(ray.mDirection);

        mNear = 1;
        mFar = sceneSize * 2;
        mWidth = sceneSize;

        mEyeVec.RightHandedBase(mUpVec, mLeftVec);
    mViewPoint = mTermination - 0.5f * sceneSize * mEyeVec;

        cout << "termination point: " << mTermination << endl;
        cout << "view point: " << mViewPoint << endl;
        cout << "scene: " << bbox << endl;

        InitRenderTexture(mNewTexture);
        InitRenderTexture(mOldTexture);
        
        cout << "eye: " << mEyeVec << " left: " << mLeftVec << " up: " << mUpVec << endl;
}


void GlobalLinesRenderer::CastGlobalLines(const float alpha, 
                                                                                  const float beta, 
                                                                                  //const int samples,
                                                                                  VssRayContainer &rays)
{
        InitScene(alpha, beta);

        // bind pixel shader implementing the front depth buffer functionality
        ApplyDepthPeeling(rays);
}


void GlobalLinesRenderer::CastGlobalLines(const SimpleRay &ray, 
                                                                                  VssRayContainer &rays)
{
        InitScene(ray);

        // bind pixel shader implementing the front depth buffer functionality
        ApplyDepthPeeling(rays);
}

void GlobalLinesRenderer::RenderObject(Intersectable *obj)
{
        mRenderer->RenderIntersectable(obj);
}


void GlobalLinesRenderer::DrawGeometry()
{ 
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        glMatrixMode(GL_MODELVIEW);

        glPushMatrix();
        { 
                //glLoadIdentity();
                ObjectContainer::const_iterator oit, oit_end = mPreprocessor->mObjects.end();

                Intersectable::NewMail();

                for (oit = mPreprocessor->mObjects.begin(); oit != oit_end; ++ oit)
                {
                        //cout << (*oit)->GetId() << " ";
                        RenderObject(*oit);
                }
        }
        glPopMatrix();
}


void GlobalLinesRenderer::SwitchRenderTextures()
{
        RenderTexture *buffer = mOldTexture;
        mOldTexture = mNewTexture;
        mNewTexture = buffer;
}


void GlobalLinesRenderer::ComputeLookAt(const float alpha, 
                                                                                const float beta,
                                                                                Vector3 &eye, 
                                                                                Vector3 &up, 
                                                                                Vector3 &left)
{
        eye.x = sin(alpha) * cos(beta);
        eye.y = sin(alpha) * sin(beta);
        eye.z = cos(alpha);

        eye.RightHandedBase(up, left);
}


void GlobalLinesRenderer::InitGl()
{
        InitDevIl();

    glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
        glutInitWindowPosition(50, 50);
        glutInitWindowSize(512, 512);
        glutCreateWindow("TestRenderDepthTexture");  

        int err = glewInit();
        if (GLEW_OK != err)
        {
                // problem: glewInit failed, something is seriously wrong
                fprintf(stderr, "GLEW Error: %s\n", glewGetErrorString(err));
                exit(-1);
        }  
        
        glutKeyboardFunc(Keyboard);
        glutDisplayFunc(Display);
        glutIdleFunc(Idle);
        glutReshapeFunc(Reshape);

        Reshape(512, 512);
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();

        // initialise the receiving buffers
        mNewDepthBuffer = new float[mTexWidth * mTexHeight];
        mNewItemBuffer = new unsigned char[mTexWidth * mTexHeight * 4];

        mOldDepthBuffer = new float[mTexWidth * mTexHeight];
    mOldItemBuffer = new unsigned char[mTexWidth * mTexHeight * 4];

        for (int i = 0; i < mTexWidth * mTexHeight; ++ i)
        {
                mNewDepthBuffer[i] = 1;
                mOldDepthBuffer[i] = 1;

                mNewItemBuffer[i * 4]     = 255;
                mNewItemBuffer[i * 4 + 1] = 255;
                mNewItemBuffer[i * 4 + 2] = 255;
                mNewItemBuffer[i * 4 + 3] = 255;

                mOldItemBuffer[i * 4]     = 255;
                mOldItemBuffer[i * 4 + 1] = 255;
                mOldItemBuffer[i * 4 + 2] = 255;
                mOldItemBuffer[i * 4 + 3] = 255;
        }

        /*gluLookAt(mViewPoint.x, mViewPoint.y, mViewPoint.z, 
                          midPoint.x, midPoint.y, midPoint.z, 
                          0, 1, 0);
*/
        gluLookAt(0, 0, 3, 0, 0, 0, 0, 1, 0);

        //glDisable(GL_CULL_FACE);
        glEnable(GL_CULL_FACE);
        glDisable(GL_LIGHTING);
        glDisable(GL_COLOR_MATERIAL);
        glEnable(GL_DEPTH_TEST); 
        glClearColor(0.1, 0.2, 0.3, 1);
        
        // A square, mipmapped, anisotropically filtered 8-bit RGBA texture with
        // depth and stencil.
        // Note that RT_COPY_TO_TEXTURE is required for depth textures on ATI hardware
        
        mNewTexture = new RenderTexture(mTexWidth, mTexHeight, true, true);
#ifdef ATI
        mNewTexture->Initialize(true, true, false, true, true, 8, 8, 8, 8, RenderTexture::RT_COPY_TO_TEXTURE);
#else
        mNewTexture->Initialize(true, true, false, true, true, 8, 8, 8, 8);//, RenderTexture::RT_COPY_TO_TEXTURE);
#endif

        mOldTexture = new RenderTexture(mTexWidth, mTexHeight, true, true);

#ifdef ATI
        mOldTexture ->Initialize(true, true, false, true, true, 8, 8, 8, 8, RenderTexture::RT_COPY_TO_TEXTURE);
#else
        mOldTexture ->Initialize(true, true, false, true, true, 8, 8, 8, 8);//, RenderTexture::RT_COPY_TO_TEXTURE);
#endif

        // Setup Cg
        cgSetErrorCallback(cgErrorCallback);

        // Create cgContext.
        sCgContext = cgCreateContext();

        // get the best profile for this hardware
        sCgFragmentProfile = cgGLGetLatestProfile(CG_GL_FRAGMENT);
        
        //assert(sCgFragmentProfile != CG_PROFILE_UNKNOWN);
        cgGLSetOptimalOptions(sCgFragmentProfile);

        sCgDepthPeelingProgram = 
                cgCreateProgramFromFile(sCgContext, 
                                                                CG_SOURCE,
                                                                mNewTexture->IsRectangleTexture() ? 
                                                                "../src/depth_peelingRect.cg" : "../src/depth_peeling2d.cg", 
                                                                GLEW_ARB_fragment_program ? CG_PROFILE_ARBFP1 : CG_PROFILE_FP30,
                                                                NULL,
                                                                NULL);

        if(sCgDepthPeelingProgram != NULL)
        {
                cgGLLoadProgram(sCgDepthPeelingProgram);
                sTextureParam = cgGetNamedParameter(sCgDepthPeelingProgram, "depthTex");  
                
                // we need size of texture for scaling
                if (!mNewTexture->IsRectangleTexture()) 
                {
                        sTexWidthParam = cgGetNamedParameter(sCgDepthPeelingProgram, "texWidth");
                }

                sStepSizeParam = cgGetNamedParameter(sCgDepthPeelingProgram, "stepSize"); 

                cgGLSetParameter1f(sTexWidthParam, (float)mTexWidth);
                cgGLSetParameter1f(sStepSizeParam, mEpsilon);
        }

        sCgPassThroughProgram = 
                cgCreateProgramFromFile(sCgContext, 
                                                                CG_SOURCE,
                                                                "../src/passthrough.cg", 
                                                                GLEW_ARB_fragment_program ? CG_PROFILE_ARBFP1 : CG_PROFILE_FP30,
                                                                NULL,
                                                                NULL);

        if(sCgPassThroughProgram != NULL)
        {
                cgGLLoadProgram(sCgPassThroughProgram);
        }

        const float alpha = 1.1;
        const float beta = 0.9;
        InitScene(alpha, beta);

        PrintGLerror("init");
}


Intersectable *GlobalLinesRenderer::ExtractSamplePoint(float *depthBuffer,
                                                                                                           unsigned char *itemBuffer,
                                                                                                           const int x, 
                                                                                                           const int y,
                                                                                                           Vector3 &hitPoint,
                                                                                                           const bool isFrontBuffer) const
{
        const int depthIndex = x + mTexWidth * y;
        const int itemIndex = 4 * depthIndex;

        const float depth = depthBuffer[depthIndex];
        const float eyeDist = mNear + (mFar - mNear) * depth;
        
        const float leftDist = -0.5f * mWidth + mWidth * ((float)x + 0.5f) / mTexWidth;
        //const float leftDist = 0.5f * mWidth - mWidth * ((float)x + 0.5f) / mTexWidth;
        
        const float upDist = -0.5f * mWidth + mWidth * ((float)y + 0.5f) / mTexHeight;
        //const float upDist = 0.5f * mWidth - mWidth * ((float)y + 0.5f) / mTexHeight;

        hitPoint = mViewPoint + 
                       eyeDist * mEyeVec + 
                           upDist * mUpVec +
                           leftDist * mLeftVec;
                                
        unsigned char r = itemBuffer[itemIndex];
        unsigned char g = itemBuffer[itemIndex + 1];
        unsigned char b = itemBuffer[itemIndex + 2];
                        
        // 3 times 255 means no valid object
        if ((r == 255) && (g == 255) && (b == 255))
                return NULL;

        const int id = mRenderer->GetId(r, g, b);
        //cout << "r: " << (int)r << "g: " << (int)g << " b: " << (int)b << " id: " << id << "|";
        Intersectable *intersect = mPreprocessor->GetObjectById(id);

        const Vector3 dir = isFrontBuffer ? mEyeVec : -mEyeVec;
        // HACK: assume triangle intersectable
        const Vector3 norm = intersect->GetNormal(0); 

        // test for invalid view space
        if (DotProd(dir, norm) >= -Limits::Small) 
                return NULL;

        return intersect;
}


bool GlobalLinesRenderer::ProcessDepthBuffer(VssRayContainer &vssRays, 
                                                                                         const bool oldBufferInitialised,
                                                                                         const int pass)
{
        GrabDepthBuffer(mNewDepthBuffer, mNewTexture);
        GrabItemBuffer(mNewItemBuffer, mNewTexture);

        if (oldBufferInitialised)
        {
                GrabDepthBuffer(mOldDepthBuffer, mOldTexture);
                GrabItemBuffer(mOldItemBuffer, mOldTexture);
        }
        else
        {
                for (int i = 0; i < mTexWidth * mTexHeight; ++ i)
                {
                        mOldDepthBuffer[i] = 0;

                        mOldItemBuffer[i * 4]     = 255;
                        mOldItemBuffer[i * 4 + 1] = 255;
                        mOldItemBuffer[i * 4 + 2] = 255;
                        mOldItemBuffer[i * 4 + 3] = 255;
                }
        }

        /////////////////
        // test for validity

        bool buffersEqual = true;
        bool bufferEmpty = true;

        for (int y = 0; y < mTexHeight; ++ y)
        {
                for (int x = 0; x < mTexWidth; ++ x)
                {
                        const int depthIndex = x + mTexWidth * y;   
                        const int itemIndex = 4 * depthIndex;
                
                        if (mOldItemBuffer[itemIndex] != mNewItemBuffer[itemIndex])
                        {
                                buffersEqual = false;
                        }

                        unsigned char r = mNewItemBuffer[itemIndex];
                        unsigned char g = mNewItemBuffer[itemIndex + 1];
                        unsigned char b = mNewItemBuffer[itemIndex + 2];

                        // 3 times 255 means no valid object
                        if (!((r == 255) && (g == 255) && (b == 255)))
                        {
                                bufferEmpty = false;
                        }
                }
                
                // early exit
                if (!buffersEqual && !bufferEmpty)
                        break;
        }

        // depth buffer not valid
        if (buffersEqual || bufferEmpty)
        {
                cout << "stopped at layer " << pass << endl;
                return false;
        }

        for (int y = 0; y < mTexHeight; ++ y)
        {
                for (int x = 0; x < mTexWidth; ++ x)
                {
                        Vector3 newPt, oldPt;

                        Intersectable *termObj1 = ExtractSamplePoint(mNewDepthBuffer, 
                                                                                                                 mNewItemBuffer, 
                                                                                                                 x, 
                                                                                                                 y, 
                                                                                                                 newPt, 
                                                                                                                 true);

                        Intersectable *termObj2 = ExtractSamplePoint(mOldDepthBuffer, 
                                                                                                                 mOldItemBuffer, 
                                                                                                                 x, 
                                                                                                                 y, 
                                                                                                                 oldPt, 
                                                                                                                 false);

                        if (!termObj1 && !termObj2) // we do not create a ray
                                continue;

                        Vector3 clippedOldPt, clippedNewPt;

                        ClipToViewSpaceBox(oldPt, newPt, clippedOldPt, clippedNewPt);
                        //clippedOldPt = oldPt;
                        //clippedNewPt = newPt;

                        // create rays in both directions
                        if (termObj1)
                        {
                                vssRays.push_back(new VssRay(clippedOldPt, clippedNewPt, NULL, termObj1, pass));
                                //cout << "new pt: " << newPt << endl;
                        }

                        if (mSampleReverse && termObj2)
                        {
                                vssRays.push_back(new VssRay(clippedNewPt, clippedOldPt, NULL, termObj2, pass));
                                //cout << "old pt: " << oldPt << endl;
                        }
                }
        }

        return true;
}


bool GlobalLinesRenderer::ClipToViewSpaceBox(const Vector3 &origin,
                                                                                         const Vector3 &termination,
                                                                                         Vector3 &clippedOrigin,
                                                                                         Vector3 &clippedTermination)
{
        Ray ray(origin, termination - origin, Ray::LINE_SEGMENT);       
        ray.Precompute();
        
        float tmin, tmax;
        
        //const AxisAlignedBox3 bbox = mPreprocessor->mViewCellsManager->GetViewSpaceBox();
        // hack
        const AxisAlignedBox3 bbox = mPreprocessor->mKdTree->GetBox();

        if ((!bbox.ComputeMinMaxT(ray, &tmin, &tmax)) ||
                tmin>=tmax)
        {
                return false;
        }
        
        if (tmin >= 1.0f || tmax <=0.0f)
                return false;

        if (tmin > 0.0f)
                clippedOrigin = ray.Extrap(tmin);
        else
                clippedOrigin = origin;

        if (tmax < 1.0f)
                clippedTermination = ray.Extrap(tmax);
        else
                clippedTermination = termination;

        return true;
}


void GlobalLinesRenderer::Run()
{
        glutMainLoop();
}


void GlobalLinesRenderer::Visualize(const VssRayContainer &vssRays)
{
        Exporter *exporter = Exporter::GetExporter("globalLines.wrl");
        
        if (!exporter)
                return;

        exporter->SetWireframe();
        //exporter->ExportGeometry(preprocessor->mObjects);
        exporter->SetFilled();

        VssRayContainer::const_iterator vit, vit_end = vssRays.end();
        VssRayContainer outRays;

        Intersectable::NewMail();

        for (vit = vssRays.begin(); vit != vit_end; ++ vit)
        {
                VssRay *ray = *vit;
                Intersectable *obj = (*vit)->mTerminationObject;

                if (!obj->Mailed())
                {
                        obj->Mail();
                        exporter->ExportIntersectable(obj);
                }

                //if (ray->mPass == 4)
                        outRays.push_back(ray);
        }       

        exporter->ExportRays(outRays);

        delete exporter;
}


void GlobalLinesRenderer::GrabDepthBuffer(float *data, RenderTexture *rt)
{
        rt->BindDepth();
        rt->EnableTextureTarget();

        const int texFormat = GL_DEPTH_COMPONENT;
        glGetTexImage(mNewTexture->GetTextureTarget(), 0, texFormat, GL_FLOAT, data);

        mNewTexture->DisableTextureTarget();
}


void GlobalLinesRenderer::GrabItemBuffer(unsigned char *data, RenderTexture *rt)
{
        rt->Bind();
        rt->EnableTextureTarget();

        const int texFormat = GL_RGBA;
        glGetTexImage(mNewTexture->GetTextureTarget(), 0, texFormat, GL_UNSIGNED_BYTE, data);

        mNewTexture->DisableTextureTarget();
}


void GlobalLinesRenderer::ExportDepthBuffer()
{
        mNewTexture->BindDepth();
        mNewTexture->EnableTextureTarget();
        cout << "depth: " << mNewTexture->GetDepthBits() << endl;

        const int components = 1;//mNewTexture->GetDepthBits() / 8;

        float *data = new float[mTexWidth * mTexHeight * components];
        //const int texFormat = WGL_TEXTURE_DEPTH_COMPONENT_NV;
        const int texFormat = GL_DEPTH_COMPONENT;
        //const int texFormat = GL_RGBA;
        glGetTexImage(mNewTexture->GetTextureTarget(), 0, texFormat, GL_FLOAT, data);

        string filename("depth.tga");
        ilRegisterType(IL_FLOAT);

        const int depth = 1;
        const int bpp = components;

        ilTexImage(mTexWidth, mTexHeight, depth, bpp, IL_LUMINANCE, IL_FLOAT, data);
        ilSaveImage((char *const)filename.c_str());

        cout << "finished" << endl;
        delete data;
        cout << "data deleted" << endl;
        mNewTexture->DisableTextureTarget();
        PrintGLerror("grab texture");
}


void GlobalLinesRenderer::ExportItemBuffer()
{
        mNewTexture->Bind();
        mNewTexture->EnableTextureTarget();
        cout << "depth: " << mNewTexture->GetDepthBits() << endl;

        const int components = 4;//mNewTexture->GetDepthBits() / 8;

        unsigned char *data = new unsigned char [mTexWidth * mTexHeight * components];
        //const int texFormat = WGL_TEXTURE_DEPTH_COMPONENT_NV;
        const int texFormat = GL_RGBA;
        glGetTexImage(mNewTexture->GetTextureTarget(), 0, texFormat, GL_UNSIGNED_BYTE, data);

        string filename("items.jpg");
        ilRegisterType(IL_UNSIGNED_BYTE);

        const int depth = 1;
        const int bpp = components;

        ilTexImage(mTexWidth, mTexHeight, depth, bpp, IL_RGBA, IL_UNSIGNED_BYTE, data);
        ilSaveImage((char *const)filename.c_str());

        cout << "finished" << endl;
        delete data;
        cout << "data deleted" << endl;
        mNewTexture->DisableTextureTarget();
        PrintGLerror("grab texture");
}


void GlobalLinesRenderer::ApplyDepthPeeling(VssRayContainer &rays)
{
        mNewTexture->BeginCapture();
        {
                //cgGLBindProgram(sCgPassThroughProgram);
                //cgGLEnableProfile(sCgFragmentProfile);
                DrawGeometry();
        }
        mNewTexture->EndCapture();
        
        PrintGLerror("firstpass");
        if (mNewTexture->IsRectangleTexture()) cout << "rect" << endl;

        // process the buffers for the first layer
        ProcessDepthBuffer(rays, false, 0);

        for(int i = 1; i < mMaxDepth; ++ i) 
        {
                // Peel another layer
                // switch pointer between rendertextures
                SwitchRenderTextures();

                mNewTexture->BeginCapture();
                {
                        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);         

                        cgGLBindProgram(sCgDepthPeelingProgram);
                        cgGLEnableProfile(sCgFragmentProfile);
                        cgGLSetTextureParameter(sTextureParam, mOldTexture->GetDepthTextureID());
                        cgGLEnableTextureParameter(sTextureParam);

                        DrawGeometry();
                        
                        cgGLDisableTextureParameter(sTextureParam);
                        cgGLDisableProfile(sCgFragmentProfile);
                }
                mNewTexture->EndCapture();

                // process the buffers for following layer
                // jump out of loop for the first invalid buffer
                if (!ProcessDepthBuffer(rays, true, i))
                        break;
        }

        PrintGLerror("endpeeling");
}


}