void ShaderShadowMapEngine::handleEnter(
    Light *light, LightTypeE eType, RenderAction *ract, SSMEngineData *data)
{
    updateShadowTexChunk   (data);
    updateLightPassMaterial(data);
    updateBackground       (data);

    UInt32 parentTravMask = ract->getTravMask();
    ract->setTravMask(_sfShadowTravMask.getValue());

    // call specific handler for light type
    switch(eType)
    {
    case Point:
    {
        PointLight *pointL =
            boost::polymorphic_downcast<PointLight *>(light);

        handlePointLightEnter(pointL, ract, data);
    }
    break;

    case Directional:
    {
        DirectionalLight *dirL =
            boost::polymorphic_downcast<DirectionalLight *>(light);

        handleDirectionalLightEnter(dirL, ract, data);
    }
    break;

    case Spot:
    {
        SpotLight *spotL =
            boost::polymorphic_downcast<SpotLight *>(light);

        handleSpotLightEnter(spotL, ract, data);
    }
    break;

    default:
    {
        FWARNING(("ShaderShadowMapEngine::handleEnter: Unknown "
                  "light type [%u]\n", eType));
    }
    break;
    }

    ract->setTravMask(parentTravMask);
}
void TrapezoidalShadowMapEngine::handleSpotLightEnter(
    SpotLight *spotL, RenderAction *ract, TSMEngineData *data)
{
    RenderPartition *parentPart = ract->getActivePartition();

    Matrixr matEyeToWorld(parentPart->getCameraToWorld());
    Matrixr matWorldToLight;
    Matrixr matEyeToLight;

    Inherited::calcSpotLightMatrices(matWorldToLight, matEyeToLight,
                                     spotL,           matEyeToWorld );

    Matrixr matLightProj;
    Matrixr matLightFull(matWorldToLight);

    Real    shadowNear = (getShadowNear() != 0.f ? 
                          getShadowNear()       : 
                          parentPart->getNear()  );
    Real    shadowFar  = (getShadowFar () != 0.f ?
                          getShadowFar ()       :
                          parentPart->getFar()   );

    Inherited::calcPointLightRange(
        spotL, 0.01f,
        shadowNear, shadowFar, shadowNear, shadowFar);

    MatrixPerspective(matLightProj,
                      spotL->getSpotCutOff(), 1.f,
                      shadowNear, shadowFar       );

    matLightFull.multLeft(matLightProj);

    Inherited::updateShadowTexImage  (data);
    Inherited::updateShadowTexBuffers(data);
    Inherited::updateRenderTargets   (data);

    const FrustumVolume &eyeFrust   = parentPart->getFrustum();
          FrustumVolume  lightFrust;
          Matrixr        matNT;

    lightFrust.setPlanes(matLightFull);

    bool matNTValid = calcTrapezoidalTransform(matNT,
                                               matEyeToWorld, matLightFull,
                                               eyeFrust,      lightFrust   );

    if(matNTValid == false)
        return;

//    Real           cosSpotCutOff = osgCos(spotL->getSpotCutOff());

    Int32          shadowTexUnit = (this->getForceTextureUnit() >= 0) ?
                                    this->getForceTextureUnit()       : 7;
    ShaderProgram *shadowFP      = this->getShadowFragmentProgram();

    if(shadowFP == NULL)
    {
        ShaderProgramUnrecPtr newShadowFP = ShaderProgram::createLocal();
        newShadowFP->setShaderType(GL_FRAGMENT_SHADER);
        newShadowFP->setProgram   (_spotFPCode       );

        newShadowFP->addUniformVariable("TSME_matEyeToLight", matEyeToLight);
        newShadowFP->addUniformVariable("TSME_matLightProj",  matLightProj );
        newShadowFP->addUniformVariable("TSME_matNT",         matNT        );
        newShadowFP->addUniformVariable("TSME_texShadow",     shadowTexUnit);
        newShadowFP->addUniformVariable("TSME_texShadowSizeInv",
                                        Vec2f(1.f / getWidth (), 
                                              1.f / getHeight() )          );

        this->setShadowFragmentProgram(newShadowFP);
        shadowFP = newShadowFP;
    }
    else
    {
        shadowFP->updateUniformVariable("TSME_matEyeToLight", matEyeToLight);
        shadowFP->updateUniformVariable("TSME_matLightProj",  matLightProj );
        shadowFP->updateUniformVariable("TSME_matNT",         matNT        );
    }

    updateLightPassMaterial(data, 0, matNT);

    commitChanges();
    
    this->pushPartition(ract);
    {
        RenderPartition   *part   = ract->getActivePartition( );
        Window            *win    = ract->getWindow         ( );
        FrameBufferObject *target = data->getRenderTargets  (0);
        Background        *back   = data->getBackground     ( );

        part->setRenderTarget(target);
        part->setWindow      (win   );

        part->calcViewportDimension(0.f, 0.f, 1.f, 1.f,
                                    target->getWidth (),
                                    target->getHeight() );

        part->setupProjection(matLightProj, Matrixr::identity());
        part->setupViewing   (matWorldToLight                  );
        
        part->setNear        (parentPart->getNear());
        part->setFar         (parentPart->getFar ());

        part->setFrustum     (lightFrust           );

        part->setBackground  (back                 );

        part->overrideMaterial(data->getLightPassMaterials(0),
                               ract->getActNode           ( ) );

        this->recurseFrom(ract, spotL);
        ract->useNodeList(false      );

        part->overrideMaterial(NULL,
                               ract->getActNode           ( ) );
    }
    this->popPartition(ract);
}
void TrapezoidalShadowMapEngine::handlePointLightEnter(
    PointLight *pointL, RenderAction *ract, TSMEngineData *data)
{
    RenderPartition *parentPart = ract->getActivePartition();
    
    Matrixr matEyeToWorld(parentPart->getCameraToWorld());  
    Matrixr matLightProj;

    Real    shadowNear = (getShadowNear() != 0.f ? 
                          getShadowNear()       : 
                          parentPart->getNear()  );
    Real    shadowFar  = (getShadowFar () != 0.f ?
                          getShadowFar ()       :
                          parentPart->getFar()   );

    Inherited::calcPointLightRange(
        pointL, 0.01f,
        shadowNear, shadowFar, shadowNear, shadowFar);

    MatrixPerspective(matLightProj, Pi / 4.f, 1.f,
                      shadowNear, shadowFar       );
    
    Matrixr   matWorldToLight;
    Matrixr   matEyeToLight;
    MFMatrixr mfMatNT;

    mfMatNT.resize(6);

    Inherited::calcPointLightMatrices(matWorldToLight, matEyeToLight,
                                      pointL,          matEyeToWorld );

    Inherited::updatePointLightShadowTexImage  (data);
    Inherited::updatePointLightShadowTexBuffers(data);
    Inherited::updatePointLightRenderTargets   (data);

    Int32          shadowTexUnit = (this->getForceTextureUnit() >= 0) ?
                                    this->getForceTextureUnit()       : 7;
    ShaderProgram *shadowFP      = this->getShadowFragmentProgram();

    if(shadowFP == NULL)
    {
        ShaderProgramUnrecPtr newShadowFP = ShaderProgram::createLocal();
        newShadowFP->setShaderType(GL_FRAGMENT_SHADER);
        newShadowFP->setProgram   (_pointFPCode      );
        
        newShadowFP->addUniformVariable("TSME_matEyeToLight", matEyeToLight);
        newShadowFP->addUniformVariable("TSME_matLightProj",  matLightProj );
        newShadowFP->addUniformVariable("TSME_matNT",         mfMatNT      );
        newShadowFP->addUniformVariable("TSME_texShadow",     shadowTexUnit);
        newShadowFP->addUniformVariable("TSME_texShadowSizeInv",
                                        Vec2f(1.f / getWidth (), 
                                              1.f / getHeight() )          );
        
        this->setShadowFragmentProgram(newShadowFP);
        shadowFP = newShadowFP;
    }
    else
    {
        shadowFP->updateUniformVariable("TSME_matEyeToLight", matEyeToLight);
        shadowFP->updateUniformVariable("TSME_matLightProj",  matLightProj );
    }

    const FrustumVolume &eyeFrust = parentPart->getFrustum();

    for(UInt16 faceIdx = 0; faceIdx < 6; ++faceIdx)
    {
        Matrixr matWorldToLightFace (matWorldToLight         );
        matWorldToLightFace.multLeft(_matCubeFaceInv[faceIdx]);

        Matrixr matLightFull(matWorldToLightFace);
        matLightFull.multLeft(matLightProj);

        FrustumVolume lightFrust;
        Matrixr       matNT;

        lightFrust.setPlanes(matLightFull);

        bool matNTValid = 
            calcTrapezoidalTransform(mfMatNT[faceIdx],
                                     matEyeToWorld,    matLightFull,
                                     eyeFrust,         lightFrust   );

        if(matNTValid == false)
        {
            // setup a minimal partition to clear the cube face

            commitChanges();

            this->pushPartition(ract,
                                RenderPartition::CopyNothing,
                                RenderPartition::SimpleCallback);
            {
                RenderPartition   *part   = ract->getActivePartition(       );
                Window            *win    = ract->getWindow         (       );
                FrameBufferObject *target = data->getRenderTargets  (faceIdx);
                Background        *back   = data->getBackground     (       );

                part->setSetupMode(RenderPartition::ViewportSetup  |
                                   RenderPartition::BackgroundSetup );

                part->setRenderTarget(target);
                part->setWindow      (win   );

                part->calcViewportDimension(0.f, 0.f, 1.f, 1.f,
                                            target->getWidth (),
                                            target->getHeight() );
                
                part->setBackground(back);

                RenderPartition::SimpleDrawCallback emptyCubeFaceDraw =
                    boost::bind(
                        &TrapezoidalShadowMapEngine::emptyCubeFaceDrawFunc,
                        this, _1);

                part->dropFunctor(emptyCubeFaceDraw);
            }
            this->popPartition(ract);
        }
        else
        {
            updateLightPassMaterial(data, faceIdx, mfMatNT[faceIdx]);
        
            commitChanges();

            this->pushPartition(ract);
            {
                RenderPartition   *part   = ract->getActivePartition(       );
                Window            *win    = ract->getWindow         (       );
                FrameBufferObject *target = data->getRenderTargets  (faceIdx);
                Background        *back   = data->getBackground     (       );

                part->setRenderTarget(target);
                part->setWindow      (win   );

                part->calcViewportDimension(0.f, 0.f, 1.f, 1.f,
                                            target->getWidth (),
                                            target->getHeight() );

                part->setupProjection(matLightProj, Matrixr::identity());
                part->setupViewing   (matWorldToLightFace              );

                part->setNear        (parentPart->getNear());
                part->setFar         (parentPart->getFar ());
            
                part->setFrustum     (lightFrust           );
                
                part->setBackground  (back                 );

                part->overrideMaterial(data->getLightPassMaterials(faceIdx),
                                       ract->getActNode           (       ) );

                this->recurseFrom(ract, pointL);
                ract->useNodeList(false       );

                part->overrideMaterial(NULL,
                                       ract->getActNode           (       ) );
            }
            this->popPartition(ract);
        }
    }

    shadowFP->updateUniformVariable("TSME_matNT", mfMatNT);
}