OpenSceneGraph/src/osgVolume/FixedFunctionTechnique.cpp

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2009 Robert Osfield 
 *
 * This library is open source and may be redistributed and/or modified under  
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 * OpenSceneGraph Public License for more details.
*/

#include <osgVolume/FixedFunctionTechnique>
#include <osgVolume/VolumeTile>

#include <osg/Billboard>
#include <osg/Texture3D>
#include <osg/Geometry>
#include <osg/ClipNode>
#include <osg/Material>
#include <osg/TexGenNode>
#include <osg/AlphaFunc>
#include <osg/BlendFunc>
#include <osg/BlendEquation>
#include <osg/TexEnv>
#include <osg/io_utils>

using namespace osgVolume;

FixedFunctionTechnique::FixedFunctionTechnique()
{
}

FixedFunctionTechnique::FixedFunctionTechnique(const FixedFunctionTechnique& fft,const osg::CopyOp& copyop):
    VolumeTechnique(fft,copyop)
{
}

FixedFunctionTechnique::~FixedFunctionTechnique()
{
}

osg::Node* createCube(float size,float alpha, unsigned int numSlices, float sliceEnd=1.0f)
{

    // set up the Geometry.
    osg::Geometry* geom = new osg::Geometry;

    float halfSize = size*0.5f;
    float y = halfSize;
    float dy =-size/(float)(numSlices-1)*sliceEnd;

    //y = -halfSize;
    //dy *= 0.5;

    osg::Vec3Array* coords = new osg::Vec3Array(4*numSlices);
    geom->setVertexArray(coords);
    for(unsigned int i=0;i<numSlices;++i, y+=dy)
    {
        (*coords)[i*4+0].set(-halfSize,y,halfSize);
        (*coords)[i*4+1].set(-halfSize,y,-halfSize);
        (*coords)[i*4+2].set(halfSize,y,-halfSize);
        (*coords)[i*4+3].set(halfSize,y,halfSize);
    }
    
    osg::Vec3Array* normals = new osg::Vec3Array(1);
    (*normals)[0].set(0.0f,-1.0f,0.0f);
    geom->setNormalArray(normals);
    geom->setNormalBinding(osg::Geometry::BIND_OVERALL);

    osg::Vec4Array* colors = new osg::Vec4Array(1);
    (*colors)[0].set(1.0f,1.0f,1.0f,alpha);
    geom->setColorArray(colors);
    geom->setColorBinding(osg::Geometry::BIND_OVERALL);

    geom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS,0,coords->size()));

    osg::Billboard* billboard = new osg::Billboard;
    billboard->setMode(osg::Billboard::POINT_ROT_WORLD);
    billboard->addDrawable(geom);
    billboard->setPosition(0,osg::Vec3(0.0f,0.0f,0.0f));
    
    return billboard;
}


void FixedFunctionTechnique::init()
{
    osg::notify(osg::NOTICE)<<"FixedFunctionTechnique::init()"<<std::endl;

    if (!_volumeTile) return;

    float alphaFuncValue = 0.1;
   
    osg::Image* image_3d = 0;
    osg::TransferFunction1D* tf = 0;
    osgVolume::Locator* masterLocator = _volumeTile->getLocator();
    osg::Texture::InternalFormatMode internalFormatMode = osg::Texture::USE_IMAGE_DATA_FORMAT; 

    image_3d = _volumeTile->getLayer()->getImage();
    
    CollectPropertiesVisitor cpv;
    if (_volumeTile->getLayer()->getProperty())
    {
        _volumeTile->getLayer()->getProperty()->accept(cpv);
    }

    if (cpv._isoProperty.valid())
    {
        alphaFuncValue = cpv._isoProperty->getValue();
    }

    if (cpv._tfProperty.valid())
    {
        tf = dynamic_cast<osg::TransferFunction1D*>(cpv._tfProperty->getTransferFunction());
    }

    if (cpv._afProperty.valid())
    {
        alphaFuncValue = cpv._afProperty->getValue();
    }


    if (_volumeTile->getLayer() && !masterLocator)
    {
        masterLocator = _volumeTile->getLayer()->getLocator();
        osg::notify(osg::NOTICE)<<"assigning locator = "<<masterLocator<<std::endl;
    }

    osg::Matrix matrix;
    if (masterLocator)
    {
        matrix = masterLocator->getTransform();
    }
    
    osg::notify(osg::NOTICE)<<"Matrix = "<<matrix<<std::endl;


    unsigned int numSlices=500;
    float sliceEnd=1.0f;
    float xSize = 1.0;
    float ySize = 1.0;
    float zSize = 1.0;
    float xMultiplier = 1.0;
    float yMultiplier = 1.0;
    float zMultiplier = 1.0;

     
    osg::BoundingBox bb(-xSize*0.5f,-ySize*0.5f,-zSize*0.5f,xSize*0.5f,ySize*0.5f,zSize*0.5f);

    osg::Texture::FilterMode minFilter = osg::Texture::NEAREST;
    osg::Texture::FilterMode magFilter = osg::Texture::NEAREST;

    float maxAxis = xSize;
    if (ySize > maxAxis) maxAxis = ySize;
    if (zSize > maxAxis) maxAxis = zSize;

    osg::Group* group = new osg::Group;
    
    osg::TexGenNode* texgenNode_0 = new osg::TexGenNode;
    texgenNode_0->setTextureUnit(0);
    texgenNode_0->getTexGen()->setMode(osg::TexGen::EYE_LINEAR);
    texgenNode_0->getTexGen()->setPlane(osg::TexGen::S, osg::Plane(xMultiplier/xSize,0.0f,0.0f,0.5f));
    texgenNode_0->getTexGen()->setPlane(osg::TexGen::T, osg::Plane(0.0f,yMultiplier/ySize,0.0f,0.5f));
    texgenNode_0->getTexGen()->setPlane(osg::TexGen::R, osg::Plane(0.0f,0.0f,zMultiplier/zSize,0.5f));
    
    group->addChild(texgenNode_0);

    float cubeSize = sqrtf(xSize*xSize+ySize*ySize+zSize*zSize);

    osg::ClipNode* clipnode = new osg::ClipNode;
    clipnode->addChild(createCube(cubeSize,1.0f, numSlices,sliceEnd));
    clipnode->createClipBox(bb);

    {
        // set up the Geometry to enclose the clip volume to prevent near/far clipping from affecting billboard
        osg::Geometry* geom = new osg::Geometry;

        osg::Vec3Array* coords = new osg::Vec3Array();
        coords->push_back(bb.corner(0));
        coords->push_back(bb.corner(1));
        coords->push_back(bb.corner(2));
        coords->push_back(bb.corner(3));
        coords->push_back(bb.corner(4));
        coords->push_back(bb.corner(5));
        coords->push_back(bb.corner(6));
        coords->push_back(bb.corner(7));

        geom->setVertexArray(coords);

        osg::Vec4Array* colors = new osg::Vec4Array(1);
        (*colors)[0].set(1.0f,1.0f,1.0f,1.0f);
        geom->setColorArray(colors);
        geom->setColorBinding(osg::Geometry::BIND_OVERALL);

        geom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::POINTS,0,coords->size()));

        osg::Geode* geode = new osg::Geode;
        geode->addDrawable(geom);
        
        clipnode->addChild(geode);
        
    }

    texgenNode_0->addChild(clipnode);

    osg::StateSet* stateset = texgenNode_0->getOrCreateStateSet();

    stateset->setMode(GL_LIGHTING,osg::StateAttribute::ON);
    stateset->setMode(GL_BLEND,osg::StateAttribute::ON);
    stateset->setAttributeAndModes(new osg::AlphaFunc(osg::AlphaFunc::GREATER,alphaFuncValue), osg::StateAttribute::ON);
    
    osg::Material* material = new osg::Material;
    material->setDiffuse(osg::Material::FRONT_AND_BACK,osg::Vec4(1.0f,1.0f,1.0f,1.0f));
    stateset->setAttributeAndModes(material);
    
    if (cpv._mipProperty.valid())
    {
        stateset->setAttribute(new osg::BlendFunc(osg::BlendFunc::ONE, osg::BlendFunc::ONE));
        stateset->setAttribute(new osg::BlendEquation(osg::BlendEquation::RGBA_MAX));
    }


    // set up the 3d texture itself,
    // note, well set the filtering up so that mip mapping is disabled,
    // gluBuild3DMipsmaps doesn't do a very good job of handled the
    // imbalanced dimensions of the 256x256x4 texture.
    osg::Texture3D* texture3D = new osg::Texture3D;
    texture3D->setResizeNonPowerOfTwoHint(false);
    texture3D->setFilter(osg::Texture3D::MIN_FILTER,minFilter);
    texture3D->setFilter(osg::Texture3D::MAG_FILTER, magFilter);
    texture3D->setWrap(osg::Texture3D::WRAP_R,osg::Texture3D::CLAMP_TO_EDGE);
    texture3D->setWrap(osg::Texture3D::WRAP_S,osg::Texture3D::CLAMP_TO_EDGE);
    texture3D->setWrap(osg::Texture3D::WRAP_T,osg::Texture3D::CLAMP_TO_EDGE);
    if (image_3d->getPixelFormat()==GL_ALPHA || 
        image_3d->getPixelFormat()==GL_LUMINANCE)
    {
        texture3D->setInternalFormatMode(osg::Texture3D::USE_USER_DEFINED_FORMAT);
        texture3D->setInternalFormat(GL_INTENSITY);
    }
    else
    {
        texture3D->setInternalFormatMode(internalFormatMode);
    }

    texture3D->setImage(image_3d);

    stateset->setTextureAttributeAndModes(0,texture3D,osg::StateAttribute::ON);

    stateset->setTextureMode(0,GL_TEXTURE_GEN_S,osg::StateAttribute::ON);
    stateset->setTextureMode(0,GL_TEXTURE_GEN_T,osg::StateAttribute::ON);
    stateset->setTextureMode(0,GL_TEXTURE_GEN_R,osg::StateAttribute::ON);

    stateset->setTextureAttributeAndModes(0,new osg::TexEnv(),osg::StateAttribute::ON);
        
        
    _node = group;
}

void FixedFunctionTechnique::update(osgUtil::UpdateVisitor* uv)
{
//    osg::notify(osg::NOTICE)<<"FixedFunctionTechnique:update(osgUtil::UpdateVisitor* nv):"<<std::endl;
}

void FixedFunctionTechnique::cull(osgUtil::CullVisitor* cv)
{
    //osg::notify(osg::NOTICE)<<"FixedFunctionTechnique::cull(osgUtil::CullVisitor* nv)"<<std::endl;    
    if (_node.valid())
    {
        _node->accept(*cv);
    }
}

void FixedFunctionTechnique::cleanSceneGraph()
{
    osg::notify(osg::NOTICE)<<"FixedFunctionTechnique::cleanSceneGraph()"<<std::endl;
}

void FixedFunctionTechnique::traverse(osg::NodeVisitor& nv)
{
    // osg::notify(osg::NOTICE)<<"FixedFunctionTechnique::traverse(osg::NodeVisitor& nv)"<<std::endl;
    if (!_volumeTile) return;

    // if app traversal update the frame count.
    if (nv.getVisitorType()==osg::NodeVisitor::UPDATE_VISITOR)
    {
        if (_volumeTile->getDirty()) _volumeTile->init();

        osgUtil::UpdateVisitor* uv = dynamic_cast<osgUtil::UpdateVisitor*>(&nv);
        if (uv)
        {
            update(uv);
            return;
        }        
        
    }
    else if (nv.getVisitorType()==osg::NodeVisitor::CULL_VISITOR)
    {
        osgUtil::CullVisitor* cv = dynamic_cast<osgUtil::CullVisitor*>(&nv);
        if (cv)
        {
            cull(cv);
            return;
        }
    }


    if (_volumeTile->getDirty()) 
    {
        osg::notify(osg::INFO)<<"******* Doing init ***********"<<std::endl;
        _volumeTile->init();
    }
}