///////////////////////////////////////////////////////////////////////////
//
//		Realistic rain real-time simulation program
//
//		Pierre Rousseau
//
///////////////////////////////////////////////////////////////////////////
//
//		Particle systems handling
//
///////////////////////////////////////////////////////////////////////////


#include "windows.h"
#include "RainCloseDropsParticles.h"
#include <OgreHardwarePixelBuffer.h>
using namespace std;


extern float startPos[3];





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


CloseDropsParticles::CloseDropsParticles(SceneManager *sceneMgr, SceneNode *parentSyst, SceneNode *parentCam)
{
    mSceneMgr = sceneMgr;
    mParentCam = parentCam;
    mParentSyst = parentSyst;

	// CHANGE THE FOLLOWING PARAMETERS TO MODIFY THE SIZES OF THE PARTICLES
    mRainWidth = 0.2f;	// ranging from 0.1 to 0.9
    mRainStreaksHeight = 1.0;
    mActiveParticlesCount = BILLBOARD_POS_TEX_SIZE * BILLBOARD_POS_TEX_SIZE;

    mParticlesNode = parentSyst->createChildSceneNode();

    mRainLightMgr = new RainLightManager(mSceneMgr);
    createLights();

    std::cout << "creating rain system" << std::endl << std::endl;
    initParticles();
}





CloseDropsParticles::~CloseDropsParticles()
{
    mSceneMgr->destroyStaticGeometry(STATIC_GEOMETRY_NAME);
    cout << "Particles destructed." << endl;
}




void CloseDropsParticles::createLights()
{
    mSceneMgr->setAmbientLight(ColourValue(1.0, 1.0, 1.0));

    mRainLightMgr->addStreetLight(ColourValue::Green, Vector3(startPos[0] + 100 , startPos[1] - HAUTEUR_OBSERVATEUR, startPos[2] + 20), 120); // green light
    mRainLightMgr->addStreetLight(ColourValue::Red, Vector3(startPos[0] + 130 , startPos[1] - HAUTEUR_OBSERVATEUR, startPos[2] + 60), 120); // red light
    mRainLightMgr->addStreetLight(ColourValue::Red + ColourValue::Green + ColourValue::Blue, Vector3(startPos[0] + 160 , startPos[1] - HAUTEUR_OBSERVATEUR, startPos[2] + 100), 120); // white light


    mRainLightMgr->finalizeLights();
}




RainLightManager *CloseDropsParticles::getLightManagerPtr()
{
    return mRainLightMgr;
}




void CloseDropsParticles::updateLights()
{
    mRainLightMgr->updateLights();
}



void CloseDropsParticles::createBillboardsPositionRenderTexture(RenderTexture *PSPosTexture, Vector3 nodePos, BillboardSet *bbSet)
{
    //initialize the render to texture related stuff

    String camName = "camera_for_" + PSPosTexture->getName();
    Camera *PSPosCamera = new Ogre::Camera(camName, mSceneMgr);

    SceneNode *mPSPosCamNode = mSceneMgr->getRootSceneNode()->createChildSceneNode();
    mPSPosCamNode->setPosition(nodePos);
    mPSPosCamNode->attachObject(PSPosCamera);

    PSPosCamera->setPosition(Vector3(0, 0, 0));
    PSPosCamera->setNearClipDistance( 10 );
    PSPosCamera->setFarClipDistance( 12 );
    PSPosCamera->setFOVy(Ogre::Radian(Ogre::Degree(90)));
    PSPosCamera->setProjectionType(PT_ORTHOGRAPHIC );
    PSPosCamera->setAspectRatio(1.0);

    mPSPosCamNode->attachObject(bbSet);

    Billboard *mBillboard = bbSet->createBillboard(Vector3(0, 0, -11));
    mBillboard->setDimensions(20, 20);
    mBillboard->setColour(ColourValue::White);

    TextureFrameListener *textureLis = new TextureFrameListener(mSceneMgr);

    PSPosTexture->addListener(textureLis);
    PSPosTexture->addViewport(PSPosCamera);
    PSPosTexture->getViewport (0)->setOverlaysEnabled (false);
    PSPosTexture->getViewport (0)->setClearEveryFrame(true);

    PSPosTexture->setAutoUpdated(false);
}





void CloseDropsParticles::createBillboardsPositionTextureMaterial(String inputTextureName)
{
    MaterialPtr posTextureMaterial = MaterialManager::getSingleton().create("rtt_material_using_" + inputTextureName, ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME);

    // alpha rejection mustn't be set, to avoid breaking the FBO

    TextureUnitState *tPosSrcUnit = posTextureMaterial->getTechnique (0)->getPass (0)->createTextureUnitState ();
    tPosSrcUnit->setTextureName (inputTextureName);
    tPosSrcUnit->setTextureFiltering (FO_POINT, FO_POINT, FO_NONE );
    tPosSrcUnit->setTextureAddressingMode(Ogre::TextureUnitState::TAM_CLAMP); // mode clamp for this texture

    posTextureMaterial->setDepthCheckEnabled (true);
    posTextureMaterial->setDepthWriteEnabled (true);

    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    // shader part
    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

    String progName;

    // fragment program which will map the generated textures
    progName = "billboardPosTexUpdater" + inputTextureName;
    HighLevelGpuProgramPtr fp = HighLevelGpuProgramManager::getSingleton().createProgram(progName, ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME, "cg", GPT_FRAGMENT_PROGRAM);
    fp->setSourceFile("billboardPosTexUpdaterFP.cg");
    fp->setParameter("profiles", "ps_2_x arbfp1");

    fp->setParameter("entry_point", "main");

    posTextureMaterial->getTechnique (0)->getPass (0)->setFragmentProgram (progName);

    posTextureMaterial->compile();
}



void CloseDropsParticles::definePosTextureAndBackup()
{
    String tmp;

    // first : define the "primary" and "secondary" RTT's
    tmp = String("billboardset_for_") + PARTICLE_POSITION_TEXTURE_NAME;
    bbSet1 = mSceneMgr->createBillboardSet(tmp);
    particlePosTexture = Root::getSingleton().getRenderSystem()->createRenderTexture (PARTICLE_POSITION_TEXTURE_NAME, BILLBOARD_POS_TEX_SIZE, BILLBOARD_POS_TEX_SIZE, TEX_TYPE_2D, PF_FLOAT32_RGB);
    createBillboardsPositionRenderTexture(particlePosTexture, Vector3(0, 10, 0), bbSet1);

    tmp = String("billboardset_for_") + PARTICLE_POSITION_BACKUP_TEXTURE_NAME;
    bbSet2 = mSceneMgr->createBillboardSet(tmp);

    // particlePosTextureBackup was already created and initialized
    particlePosTextureBackup = Root::getSingleton().getRenderSystem()->createRenderTexture (PARTICLE_POSITION_BACKUP_TEXTURE_NAME, BILLBOARD_POS_TEX_SIZE, BILLBOARD_POS_TEX_SIZE, TEX_TYPE_2D, PF_FLOAT32_RGB);

    createBillboardsPositionRenderTexture(particlePosTextureBackup, Vector3(100, 10, 0), bbSet2);

    // initialization
    createBillboardsPositionTextureMaterial(PARTICLE_POSITION_INIT_TEXTURE_NAME);
    tmp = String("rtt_material_using_") + PARTICLE_POSITION_INIT_TEXTURE_NAME;
    bbSet2->setMaterialName(tmp);

    particlePosTextureBackup->update();

    // create and bind the materials used for the billboardSets
    createBillboardsPositionTextureMaterial(PARTICLE_POSITION_BACKUP_TEXTURE_NAME);
    tmp = String("rtt_material_using_") + PARTICLE_POSITION_BACKUP_TEXTURE_NAME;
    bbSet1->setMaterialName(tmp);

    // now it's initialized, set it to normal rendering
    createBillboardsPositionTextureMaterial(PARTICLE_POSITION_TEXTURE_NAME);
    tmp = String("rtt_material_using_") + PARTICLE_POSITION_TEXTURE_NAME;
    bbSet2->setMaterialName(tmp);

}




void CloseDropsParticles::initializeBillboardsPositionTexture()
{
    // initialize the texture
    TexturePtr InitializationBillBoardPositionTexture = TextureManager::getSingleton().createManual(
                PARTICLE_POSITION_INIT_TEXTURE_NAME, // name
                ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME,
                TEX_TYPE_2D,      // type
                BILLBOARD_POS_TEX_SIZE, BILLBOARD_POS_TEX_SIZE,         // width & height
                0,                // number of mipmaps
                PF_FLOAT32_RGB,     // pixel format
                TU_DYNAMIC_WRITE_ONLY_DISCARDABLE);

    // Get the pixel buffer
    HardwarePixelBufferSharedPtr pixelBuffer = InitializationBillBoardPositionTexture->getBuffer();

    // Lock the pixel buffer and get a pixel box
    pixelBuffer->lock(HardwareBuffer::HBL_DISCARD); // for best performance use HBL_DISCARD!
    const PixelBox& pixelBox = pixelBuffer->getCurrentLock();

    float* pDest = static_cast<float*>(pixelBox.data);

    /////////////////////////////////////////////////
    //  (indPart%100) * 10 - 500, 10, (indPart/100) * 10 - 1000
    //  ((i + j * BILLBOARD_POS_TEX_SIZE )% 100) * 10 - 500, 10, ((i + j * BILLBOARD_POS_TEX_SIZE) / 100) * 10 - 1000
    /////////////////////////////////////////////////

    // Fill in some pixel data.
    for (size_t j = 0; j < BILLBOARD_POS_TEX_SIZE; j++)
        for(size_t i = 0; i < BILLBOARD_POS_TEX_SIZE; i++)
        {
            if (i + j * BILLBOARD_POS_TEX_SIZE < mActiveParticlesCount)
            {
                // the drops are initially positionned on a regular horizontal grid, with random altitude.
                *pDest++ = i / float(BILLBOARD_POS_TEX_SIZE);		// R -> X
                *pDest++ = (rand() % 10000) / 10000.0f;			// G -> Y
                *pDest++ = j / float(BILLBOARD_POS_TEX_SIZE);		// B -> Z
            }
            else
            {
                *pDest++ = 0.0;		// R -> X
                *pDest++ = 0.0;		// G -> Y
                *pDest++ = 0.0;		// B -> Z
            }
        }

    // Unlock the pixel buffer
    pixelBuffer->unlock();

    InitializationBillBoardPositionTexture->load();

}




void CloseDropsParticles::makeControlOverlay()
{
    MaterialPtr posTextureVerifMaterial1 = MaterialManager::getSingleton().create("overlayVerif1", ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME);

    posTextureVerifMaterial1->getTechnique (0)->getPass (0)->setAlphaRejectSettings(CMPF_NOT_EQUAL, 0);
    TextureUnitState *tUnitVerif = posTextureVerifMaterial1->getTechnique (0)->getPass (0)->createTextureUnitState ();
    
	//tUnitVerif->setTextureName (REFRACT_RTT_NAME);
	tUnitVerif->setTextureName (PARTICLE_POSITION_TEXTURE_NAME);

    tUnitVerif->setTextureFiltering (TFO_NONE );
    tUnitVerif->setTextureAddressingMode(Ogre::TextureUnitState::TAM_CLAMP); // mode clamp for this texture

    posTextureVerifMaterial1->compile();


    OverlayElement *posTexPanel1 = OverlayManager::getSingleton ().createOverlayElement ("Panel", "PosTexPanel1", false);
    posTexPanel1->setDimensions(0.15, 0.2);
    posTexPanel1->setPosition(0.01, 0.01);
    posTexPanel1->setMaterialName ("overlayVerif1");

    MaterialPtr posTextureVerifMaterial2 = posTextureVerifMaterial1->clone("overlayVerif2");
    TextureUnitState *tUnitVerif2 = posTextureVerifMaterial2->getTechnique (0)->getPass (0)->getTextureUnitState (0);

    tUnitVerif2->setTextureName (LIGHT_INFO_TEXTURE_NAME);

    tUnitVerif2->setTextureFiltering (TFO_NONE );
    tUnitVerif2->setTextureAddressingMode(Ogre::TextureUnitState::TAM_CLAMP);

    posTextureVerifMaterial2->compile();


    OverlayElement *posTexPanel2 = OverlayManager::getSingleton ().createOverlayElement ("Panel", "PosTexPanel2", false);
    posTexPanel2->setDimensions(0.15, 0.01);
    //posTexPanel2->setDimensions(0.15, 0.2);
    posTexPanel2->setPosition(0.01, 0.22);
    posTexPanel2->setMaterialName ("overlayVerif2");

    Overlay *posTexOverlay = OverlayManager::getSingleton ().create("PositionTextureOverlay");
    posTexOverlay->add2D ((OverlayContainer *)posTexPanel1);
    posTexOverlay->add2D ((OverlayContainer *)posTexPanel2);
    posTexOverlay->show ();
}








MeshPtr CloseDropsParticles::createHardwareBillboardMesh(String materialName, String meshName)
{
    MeshPtr msh = MeshManager::getSingleton().createManual(meshName,
                  ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME,
                  new ManualHardwareBillboardMeshLoader(materialName));

    msh->load();

    return msh;
}






void CloseDropsParticles::modifyClonedHardwareBillboardMesh(MeshPtr &msh, int partNumber)
{
    SubMesh* sm = msh->getSubMesh(0);

    Ogre::VertexData* vertex_data = sm->vertexData;

    const Ogre::VertexElement* texCoordsElem = vertex_data->vertexDeclaration->findElementBySemantic(Ogre::VES_TEXTURE_COORDINATES);
    Ogre::HardwareVertexBufferSharedPtr vbuf = vertex_data->vertexBufferBinding->getBuffer(texCoordsElem->getSource());
    unsigned char* vertex = static_cast<unsigned char*>(vbuf->lock(Ogre::HardwareBuffer::HBL_DISCARD))
                            ;
    float* pReal;

    // vertex 0
    texCoordsElem->baseVertexPointerToElement(vertex, &pReal);
    // uv
    *pReal++ = 1;
    *pReal++ = 0;
    // position texture coordinates
    *pReal++ = float(partNumber % BILLBOARD_POS_TEX_SIZE) / float(BILLBOARD_POS_TEX_SIZE);
    *pReal++ = float(partNumber / BILLBOARD_POS_TEX_SIZE) / float(BILLBOARD_POS_TEX_SIZE);

    // vertex 1
    vertex += vbuf->getVertexSize();
    texCoordsElem->baseVertexPointerToElement(vertex, &pReal);
    // uv
    *pReal++ = 0;
    *pReal++ = 0;
    // position texture coordinates
    *pReal++ = float(partNumber % BILLBOARD_POS_TEX_SIZE) / float(BILLBOARD_POS_TEX_SIZE);
    *pReal++ = float(partNumber / BILLBOARD_POS_TEX_SIZE) / float(BILLBOARD_POS_TEX_SIZE);

    // vertex 2
    vertex += vbuf->getVertexSize();
    texCoordsElem->baseVertexPointerToElement(vertex, &pReal);
    // uv
    *pReal++ = 0;
    *pReal++ = 1;
    // position texture coordinates
    *pReal++ = float(partNumber % BILLBOARD_POS_TEX_SIZE) / float(BILLBOARD_POS_TEX_SIZE);
    *pReal++ = float(partNumber / BILLBOARD_POS_TEX_SIZE) / float(BILLBOARD_POS_TEX_SIZE);

    // vertex 3
    vertex += vbuf->getVertexSize();
    texCoordsElem->baseVertexPointerToElement(vertex, &pReal);
    // uv
    *pReal++ = 1;
    *pReal++ = 1;
    // position texture coordinates
    *pReal++ = float(partNumber % BILLBOARD_POS_TEX_SIZE) / float(BILLBOARD_POS_TEX_SIZE);
    *pReal++ = float(partNumber / BILLBOARD_POS_TEX_SIZE) / float(BILLBOARD_POS_TEX_SIZE);


    vbuf->unlock();

    msh->load();
}





void CloseDropsParticles::initParticles()
{
    StaticGeometry *s;

    // we create the texture which will be used to update the particles positions.
    initializeBillboardsPositionTexture();

    createMaterial(RAIN_MATERIAL_NAME);

    // we create the billboards as static geometry in a vertex buffer on the graphics card. The positions will only be modified in a shader
    s = mSceneMgr->createStaticGeometry(STATIC_GEOMETRY_NAME);

    // we must set our region parameters so that only one region includes all the geometry
    s->setOrigin(Vector3(-5000, -500, -5000));
    s->setRegionDimensions(Vector3(10000, 1000, 10000));
    s->setRenderingDistance(100000);

    int discreetSize = int(sqrt(BILLBOARD_POS_TEX_SIZE * BILLBOARD_POS_TEX_SIZE / 3.0));

    cout << endl << endl << "Loading " << BILLBOARD_POS_TEX_SIZE * BILLBOARD_POS_TEX_SIZE << " particles" << endl;

    // we should position the particles so that they cover the whole world (to avoid clipping)
    for (int indPart = 0; indPart < BILLBOARD_POS_TEX_SIZE * BILLBOARD_POS_TEX_SIZE; indPart++)
    {
        String meshName = BILLBOARD_MESH_NAME + StringConverter::toString(indPart);
        // define the billboard (quad) mesh to use
        modifyClonedHardwareBillboardMesh(createHardwareBillboardMesh(RAIN_MATERIAL_NAME, meshName), indPart);

        String entName = "simple_quad_for_hardware_bilboard_" + StringConverter::toString(indPart);
        Entity *e = mSceneMgr->createEntity(entName, meshName);
        e->setQueryFlags(0x00000002);

        float indX = float( (indPart / 3) % discreetSize ) / float(discreetSize);
        float indY = (indPart % 3) / 2.0;  // three stories of droplets
        float indZ = float( (indPart / 3) / discreetSize ) / float(discreetSize);

        Vector3 pos(PARTICLES_MIN_X + (PARTICLES_MAX_X - PARTICLES_MIN_X) * indX ,
                    PARTICLES_MIN_Y + (PARTICLES_MAX_Y - PARTICLES_MIN_Y) * indY ,
                    PARTICLES_MIN_Z + (PARTICLES_MAX_Z - PARTICLES_MIN_Z) * indZ); // we give each particle a different position, to avoid clipping

		s->addEntity(e, pos);


        // progress bar
        printf("|");
        int discret = 50;
        int prog = int (discret * indPart / (BILLBOARD_POS_TEX_SIZE * BILLBOARD_POS_TEX_SIZE) );
        for (int car=0 ; car <= prog ; car++)
            printf("#");
        for (int car=prog+1 ; car <= discret ; car++)
            printf(" ");
        printf("|\r");
    }

    s->build();

    cout << endl << endl << "Particles loaded" << endl << endl;
}




void CloseDropsParticles::updatePositionTexture(bool primary)
{
    if (static_cast<MaterialPtr>(MaterialManager::getSingleton().getByName(RAIN_MATERIAL_NAME))->
            getTechnique (0)->getPass (0)->getTextureUnitState (1)->isBlank())
    {
        std::cout << "merde !!!" << std::endl;
    }

    if (primary)
    {
        particlePosTexture->update();
        static_cast<MaterialPtr>(MaterialManager::getSingleton().getByName(RAIN_MATERIAL_NAME))->getTechnique (0)->getPass (0)->getTextureUnitState (1)->setTextureName(PARTICLE_POSITION_TEXTURE_NAME);
        static_cast<MaterialPtr>(MaterialManager::getSingleton().getByName(RAIN_MATERIAL_NAME))->compile();
    }
    else
    {
        particlePosTextureBackup->update();
        static_cast<MaterialPtr>(MaterialManager::getSingleton().getByName(RAIN_MATERIAL_NAME))->getTechnique (0)->getPass (0)->getTextureUnitState (1)->setTextureName(PARTICLE_POSITION_BACKUP_TEXTURE_NAME);
        static_cast<MaterialPtr>(MaterialManager::getSingleton().getByName(RAIN_MATERIAL_NAME))->compile();
    }
}













void CloseDropsParticles::createMaterial(String name)
{
    dropsTexturesMaterial = MaterialManager::getSingleton().create(name, ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME);

#ifndef SNOW

    mCamera = createDropsCamera();
    mParentCam->attachObject(mCamera);

    dropsTexture = Root::getSingleton().getRenderSystem()->createRenderTexture (REFRACT_RTT_NAME, RTTSIZE, RTTSIZE, TEX_TYPE_2D, PF_R8G8B8);
    dropsTexture->setAutoUpdated(true); // the main RTT texture will be updated automatically
    TextureFrameListener *textureLis = new TextureFrameListener(mSceneMgr); // to avoid seeing the drops in the rtt

    dropsTexture->addListener(textureLis);
    dropsTexture->addViewport(mCamera);
    dropsTexture->getViewport (0)->setOverlaysEnabled (false);
    dropsTexture->getViewport (0)->setClearEveryFrame(true);
#endif

    dropsTexturesMaterial->getTechnique (0)->getPass (0)->setAlphaRejectSettings(CMPF_NOT_EQUAL, 0);	// we discard the portions of the texture where alpha = 0

    TextureUnitState *createMaterialTUnit1 = dropsTexturesMaterial->getTechnique (0)->getPass (0)->createTextureUnitState ();
#ifdef SNOW

    createMaterialTUnit1->setTextureName ("flocon.png");
    dropsTexturesMaterial->getTechnique (0)->getPass (0)->setSceneBlending(SBT_TRANSPARENT_ALPHA);
#else

    createMaterialTUnit1->setTextureName (REFRACT_RTT_NAME);
#endif

    createMaterialTUnit1->setTextureFiltering (FO_POINT, FO_POINT, FO_NONE );
    createMaterialTUnit1->setTextureAddressingMode(Ogre::TextureUnitState::TAM_CLAMP); // mode wrap for this texture

    TextureUnitState *createMaterialTUnit2 = dropsTexturesMaterial->getTechnique (0)->getPass (0)->createTextureUnitState ();
    createMaterialTUnit2->setTextureName (PARTICLE_POSITION_INIT_TEXTURE_NAME); // real position texture isn't yet initialized
	
	// THE FOLLOWING LINE IS NECESSARY TO HANDLE VERTEX TEXTURE FETCH IN OGRE.
	// IT NEEDS OGRE EIHORT
	// THIS IS THE REASON WHY THE PROGRAM WILL NOT RUN PROPERLY IN DIRECTX
	// -SHOULD- BE FINE AFTER THE PROGRAM GETS PORTED TO EIHORT (OGRE 1.4)

	// createMaterialTUnit2->setBindingType(BT_VERTEX);
    
	
	
	createMaterialTUnit2->setTextureFiltering (FO_POINT, FO_POINT, FO_NONE );
    createMaterialTUnit2->setTextureAddressingMode(Ogre::TextureUnitState::TAM_CLAMP); // mode clamp for this texture

#ifndef SNOW

    String maskName = "masques/masque_" + StringConverter::toString(mRainWidth * 5.0f) + "_.tga";
    TextureUnitState *createMaterialTUnit3 = dropsTexturesMaterial->getTechnique (0)->getPass (0)->createTextureUnitState ();
    createMaterialTUnit3->setTextureName (maskName);  // because we start with billboard width = 0.5
    createMaterialTUnit3->setTextureFiltering (FO_POINT, FO_POINT, FO_NONE );
    createMaterialTUnit3->setTextureAddressingMode(Ogre::TextureUnitState::TAM_CLAMP); // mode clamp for this texture
#endif

#ifdef STREAKS

    TextureUnitState *createMaterialTUnit4 = dropsTexturesMaterial->getTechnique (0)->getPass (0)->createTextureUnitState ();
    createMaterialTUnit4->setTextureName ("shape.tga");
    createMaterialTUnit4->setTextureFiltering (FO_POINT, FO_POINT, FO_NONE );
    createMaterialTUnit4->setTextureAddressingMode(Ogre::TextureUnitState::TAM_CLAMP); // mode clamp for this texture
    dropsTexturesMaterial->getTechnique (0)->getPass (0)->setSceneBlending(SBT_TRANSPARENT_ALPHA);
#endif

#ifdef LIGHT_EXTENSION

    TextureUnitState *createMaterialTUnit5 = dropsTexturesMaterial->getTechnique (0)->getPass (0)->createTextureUnitState ();
    createMaterialTUnit5->setTextureName (LIGHT_INFO_TEXTURE_NAME);
    createMaterialTUnit5->setTextureFiltering (FO_POINT, FO_POINT, FO_NONE );
    createMaterialTUnit5->setTextureAddressingMode(Ogre::TextureUnitState::TAM_CLAMP); // mode clamp for this texture
#endif

    dropsTexturesMaterial->getTechnique (0)->setLodIndex(0);

    dropsTexturesMaterial->setDepthCheckEnabled (true);   // we activate depth test
    dropsTexturesMaterial->setDepthWriteEnabled (true);

    GPUmaterial();

    dropsTexturesMaterial->compile();
}






Camera* CloseDropsParticles::createDropsCamera()
{
    Camera *dropsCamera;
    String camName;

    dropsCamera = new Ogre::Camera("refract_drops_camera", mSceneMgr);

    dropsCamera->setPosition(Vector3(0, 0, 0));
    dropsCamera->setNearClipDistance( 1 );
    dropsCamera->setFarClipDistance( 10000 );
    dropsCamera->setFOVy(Ogre::Radian(FOVyRtt));  // large FOVy, 170
    dropsCamera->setAspectRatio(4.0f/3.0f);
    dropsCamera->setLodBias(0.01);

    return dropsCamera;
}


void CloseDropsParticles::updateFragmentProgramParameter(const String &name, float value)
{
    GpuProgramParametersSharedPtr paramsFP = dropsTexturesMaterial->getTechnique (0)->getPass (0)->getFragmentProgramParameters ();

    paramsFP->setNamedConstant(name, value);
}



void CloseDropsParticles::updateFragmentProgramParameter(const String &name, Vector3 value)
{
    GpuProgramParametersSharedPtr paramsFP = dropsTexturesMaterial->getTechnique (0)->getPass (0)->getFragmentProgramParameters ();

    paramsFP->setNamedConstant(name, value);
}



void CloseDropsParticles::updateFragmentProgramParameter(const String &name, Vector4 value)
{
    GpuProgramParametersSharedPtr paramsFP = dropsTexturesMaterial->getTechnique (0)->getPass (0)->getFragmentProgramParameters ();

    paramsFP->setNamedConstant(name, value);
}



void CloseDropsParticles::updateTimeSinceLastFrame(float tslf)
{
    String tmpstr = String("rtt_material_using_") + PARTICLE_POSITION_TEXTURE_NAME;
    GpuProgramParametersSharedPtr paramsPosFP = static_cast<MaterialPtr>(MaterialManager::getSingleton().getByName(tmpstr))->getTechnique (0)->getPass (0)->getFragmentProgramParameters ();
    paramsPosFP->setNamedConstant("tslf", tslf);
    // two distinct materials are used for position update, let's synchronize the second
    tmpstr = String("rtt_material_using_") + PARTICLE_POSITION_BACKUP_TEXTURE_NAME;
    paramsPosFP = static_cast<MaterialPtr>(MaterialManager::getSingleton().getByName(tmpstr))->getTechnique (0)->getPass (0)->getFragmentProgramParameters ();
    paramsPosFP->setNamedConstant("tslf", tslf);
}


void CloseDropsParticles::updateRainBilboardSideLength(float rainBbSide)
{
    GpuProgramParametersSharedPtr paramsVP = dropsTexturesMaterial->getTechnique (0)->getPass (0)->getVertexProgramParameters ();
    paramsVP->setNamedConstant("rainBbSide", rainBbSide);
}

void CloseDropsParticles::updateStreaksHeight(float streaksHeight)
{
#ifdef STREAKS
    GpuProgramParametersSharedPtr paramsVP = dropsTexturesMaterial->getTechnique (0)->getPass (0)->getVertexProgramParameters ();
    paramsVP->setNamedConstant("streaksHeight", streaksHeight);
#endif

}

void CloseDropsParticles::updateLightCount(float nbLights)
{
#ifdef LIGHT_EXTENSION
    GpuProgramParametersSharedPtr paramsFP = dropsTexturesMaterial->getTechnique (0)->getPass (0)->getFragmentProgramParameters ();
    paramsFP->setNamedConstant("nbLights", nbLights);
#endif
}

void CloseDropsParticles::updateViewPos(Vector3 viewPos)
{
    GpuProgramParametersSharedPtr paramsVP = dropsTexturesMaterial->getTechnique (0)->getPass (0)->getVertexProgramParameters ();
    paramsVP->setNamedConstant("viewPos", viewPos);
}

void CloseDropsParticles::updateViewDir(Vector3 viewDir)
{
    GpuProgramParametersSharedPtr paramsVP = dropsTexturesMaterial->getTechnique (0)->getPass (0)->getVertexProgramParameters ();
    paramsVP->setNamedConstant("viewDir", viewDir);
}

void CloseDropsParticles::updateFallVector(Vector3 fallVect)
{
    String tmpstr = String("rtt_material_using_") + PARTICLE_POSITION_TEXTURE_NAME;
    GpuProgramParametersSharedPtr paramsPosFP = static_cast<MaterialPtr>(MaterialManager::getSingleton().getByName(tmpstr))->getTechnique (0)->getPass (0)->getFragmentProgramParameters ();
    paramsPosFP->setNamedConstant("fallVect", fallVect);
    // two distinct materials are used for position update, let's synchronize the second
    tmpstr = String("rtt_material_using_") + PARTICLE_POSITION_BACKUP_TEXTURE_NAME;
    paramsPosFP = static_cast<MaterialPtr>(MaterialManager::getSingleton().getByName(tmpstr))->getTechnique (0)->getPass (0)->getFragmentProgramParameters ();
    paramsPosFP->setNamedConstant("fallVect", fallVect);


#ifdef STREAKS
    // needed also in the vertex shader, to bend the streaks
    GpuProgramParametersSharedPtr paramsVP = dropsTexturesMaterial->getTechnique (0)->getPass (0)->getVertexProgramParameters ();
    paramsVP->setNamedConstant("fallVect", fallVect);
#endif
}

void CloseDropsParticles::updateBoxMin(Vector3 boxMin)
{
    GpuProgramParametersSharedPtr paramsVP = dropsTexturesMaterial->getTechnique (0)->getPass (0)->getVertexProgramParameters ();
    paramsVP->setNamedConstant("boxMin", boxMin);
}

void CloseDropsParticles::updateBoxMax(Vector3 boxMax)
{
    GpuProgramParametersSharedPtr paramsVP = dropsTexturesMaterial->getTechnique (0)->getPass (0)->getVertexProgramParameters ();
    paramsVP->setNamedConstant("boxMax", boxMax);
}

void CloseDropsParticles::updateLastMove(Vector3 lastMove)
{
    String tmpstr = String("rtt_material_using_") + PARTICLE_POSITION_TEXTURE_NAME;
    GpuProgramParametersSharedPtr paramsPosFP = static_cast<MaterialPtr>(MaterialManager::getSingleton().getByName(tmpstr))->getTechnique (0)->getPass (0)->getFragmentProgramParameters ();
    paramsPosFP->setNamedConstant("lastMove", lastMove);
    // two distinct materials are used for position update, let's synchronize the second
    tmpstr = String("rtt_material_using_") + PARTICLE_POSITION_BACKUP_TEXTURE_NAME;
    paramsPosFP = static_cast<MaterialPtr>(MaterialManager::getSingleton().getByName(tmpstr))->getTechnique (0)->getPass (0)->getFragmentProgramParameters ();
    paramsPosFP->setNamedConstant("lastMove", lastMove);
}

void CloseDropsParticles::updateRandomMove(Vector3 randomMove)
{
    String tmpstr = String("rtt_material_using_") + PARTICLE_POSITION_TEXTURE_NAME;
    GpuProgramParametersSharedPtr paramsPosFP = static_cast<MaterialPtr>(MaterialManager::getSingleton().getByName(tmpstr))->getTechnique (0)->getPass (0)->getFragmentProgramParameters ();
    paramsPosFP->setNamedConstant("randomMove", randomMove);
    // two distinct materials are used for position update, let's synchronize the second
    tmpstr = String("rtt_material_using_") + PARTICLE_POSITION_BACKUP_TEXTURE_NAME;
    paramsPosFP = static_cast<MaterialPtr>(MaterialManager::getSingleton().getByName(tmpstr))->getTechnique (0)->getPass (0)->getFragmentProgramParameters ();
    paramsPosFP->setNamedConstant("randomMove", randomMove);
}





void CloseDropsParticles::updateShaderParameters(float tslf, float rainBbSide,
        float streaksHeight, int nbLights,
        Vector3 viewPos, Vector3 viewDir, Vector3 fallVect, Vector3 boxMin, Vector3 boxMax, Vector3 lastMove, Vector3 randomMove, int useShader)
{
    // data to update :

    // floats :
    // time since last frame (in seconds)
    // particle count
    // billboard position texture side length
    // billboard side length
    // streaks height
    // number of lights

    // vec3 :
    // viewer position
    // view direction
    // fall vector (including wind)
    // minimum box position
    // maximum box position
    // viewer movement to compensate (in box coordinates)
    // random displacement when respawning the particle


    // actualizing parameters for the position update shader

    String tmpstr = String("rtt_material_using_") + PARTICLE_POSITION_TEXTURE_NAME;
    GpuProgramParametersSharedPtr paramsPosFP = static_cast<MaterialPtr>(MaterialManager::getSingleton().getByName(tmpstr))->getTechnique (0)->getPass (0)->getFragmentProgramParameters ();
    paramsPosFP->setNamedConstant("tslf", tslf);
    paramsPosFP->setNamedConstant("randomMove", randomMove);
    paramsPosFP->setNamedConstant("lastMove", lastMove);
    paramsPosFP->setNamedConstant("fallVect", fallVect);
    // two distinct materials are used for position update, let's synchronize the second
    tmpstr = String("rtt_material_using_") + PARTICLE_POSITION_BACKUP_TEXTURE_NAME;
    paramsPosFP = static_cast<MaterialPtr>(MaterialManager::getSingleton().getByName(tmpstr))->getTechnique (0)->getPass (0)->getFragmentProgramParameters ();
    paramsPosFP->setNamedConstant("tslf", tslf);
    paramsPosFP->setNamedConstant("randomMove", randomMove);
    paramsPosFP->setNamedConstant("lastMove", lastMove);
    paramsPosFP->setNamedConstant("fallVect", fallVect);


    // actualizing vertex program parameters

    GpuProgramParametersSharedPtr paramsVP = dropsTexturesMaterial->getTechnique (0)->getPass (0)->getVertexProgramParameters ();
    paramsVP->setNamedConstant("viewPos", viewPos);
    paramsVP->setNamedConstant("viewDir", viewDir);
    paramsVP->setNamedConstant("boxMin", boxMin);
    paramsVP->setNamedConstant("boxMax", boxMax);
    paramsVP->setNamedConstant("rainBbSide", rainBbSide);
#ifdef STREAKS

    paramsVP->setNamedConstant("streaksHeight", streaksHeight);
#endif


    // actualizing fragment program parameters

    GpuProgramParametersSharedPtr paramsFP = dropsTexturesMaterial->getTechnique (0)->getPass (0)->getFragmentProgramParameters ();
#ifdef LIGHT_EXTENSION

    paramsFP->setNamedConstant("nbLights", nbLights);
#endif
}


void CloseDropsParticles::GPUmaterial()
{
    // vertex program which will modify texture coordinates
    HighLevelGpuProgramPtr vp = HighLevelGpuProgramManager::getSingleton().createProgram("gouttesTexCoordsVP", ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME, "cg", GPT_VERTEX_PROGRAM);
    vp->setSourceFile("gouttesTexCoordsVP.cg");
    vp->setParameter("profiles", "vs_3_0 vp40");
#ifdef STREAKS

    vp->setParameter("entry_point", "mainStreaks");
#else

    vp->setParameter("entry_point", "mainNoStreaks");
#endif

    // vertex program binding
    dropsTexturesMaterial->getTechnique (0)->getPass (0)->setVertexProgram ("gouttesTexCoordsVP");

    // we give it some parameters
    GpuProgramParametersSharedPtr paramsVP = dropsTexturesMaterial->getTechnique (0)->getPass (0)->getVertexProgramParameters ();
    paramsVP->setNamedAutoConstant("worldviewproj", GpuProgramParameters::ACT_WORLDVIEWPROJ_MATRIX);
    paramsVP->setNamedAutoConstant("worldview", GpuProgramParameters::ACT_WORLDVIEW_MATRIX);


    // fragment program which will map the generated textures
    HighLevelGpuProgramPtr fp = HighLevelGpuProgramManager::getSingleton().createProgram("gouttesTexCoordsFP", ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME, "cg", GPT_FRAGMENT_PROGRAM);
    fp->setSourceFile("gouttesTexCoordsFP.cg");
    fp->setParameter("profiles", "ps_3_0 fp40");


#ifdef SNOW

    fp->setParameter("entry_point", "main_Snow_noLight");

#else

#ifdef STREAKS

#ifdef LIGHT_EXTENSION

    fp->setParameter("entry_point", "main_Streaks_Light");
#else  // LIGHT

    fp->setParameter("entry_point", "main_Streaks_noLight");
#endif  // LIGHT

#else  // STREAKS

#ifdef LIGHT_EXTENSION

    fp->setParameter("entry_point", "main_noStreaks_Light");
#else  // LIGHT

    fp->setParameter("entry_point", "main_noStreaks_noLight");
#endif  // LIGHT

#endif  // STREAKS

#endif  // SNOW



    dropsTexturesMaterial->getTechnique (0)->getPass (0)->setFragmentProgram ("gouttesTexCoordsFP");


#ifdef LIGHT_EXTENSION

    GpuProgramParametersSharedPtr paramsFP = dropsTexturesMaterial->getTechnique (0)->getPass (0)->getFragmentProgramParameters ();
    paramsFP->setNamedAutoConstant("worldview", GpuProgramParameters::ACT_WORLDVIEW_MATRIX);

    // lighting
    paramsFP->setNamedAutoConstant("colAmb", GpuProgramParameters::ACT_AMBIENT_LIGHT_COLOUR);

#endif  //LIGHT
}