examples/osgcallback/osgcallback.cpp

/* OpenSceneGraph example, osgcallback.
*
*  Permission is hereby granted, free of charge, to any person obtaining a copy
*  of this software and associated documentation files (the "Software"), to deal
*  in the Software without restriction, including without limitation the rights
*  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
*  copies of the Software, and to permit persons to whom the Software is
*  furnished to do so, subject to the following conditions:
*
*  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
*  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
*  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
*  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
*  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
*  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
*  THE SOFTWARE.
*/

#include <osgViewer/Viewer>

#include <osg/Transform>
#include <osg/Billboard>
#include <osg/Geode>
#include <osg/Group>
#include <osg/Notify>

#include <osgDB/Registry>
#include <osgDB/ReadFile>

#include <osgGA/TrackballManipulator>
#include <osgGA/FlightManipulator>
#include <osgGA/DriveManipulator>

#include <osgUtil/Optimizer>

#include <iostream>

class UpdateCallback : public osg::NodeCallback
{
        virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
        {
            std::cout<<"update callback - pre traverse"<<node<<std::endl;
            traverse(node,nv);
            std::cout<<"update callback - post traverse"<<node<<std::endl;
        }
};

class CullCallback : public osg::NodeCallback
{
        virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
        {
            std::cout<<"cull callback - pre traverse"<<node<<std::endl;
            traverse(node,nv);
            std::cout<<"cull callback - post traverse"<<node<<std::endl;
        }
};

class DrawableDrawCallback : public osg::Drawable::DrawCallback
{
        virtual void drawImplementation(osg::RenderInfo& renderInfo,const osg::Drawable* drawable) const
        {
            std::cout<<"draw call back - pre drawImplementation"<<drawable<<std::endl;
            drawable->drawImplementation(renderInfo);
            std::cout<<"draw call back - post drawImplementation"<<drawable<<std::endl;
        }
};

struct DrawableUpdateCallback : public osg::Drawable::UpdateCallback
{
    virtual void update(osg::NodeVisitor*, osg::Drawable* drawable)
    {
        std::cout<<"Drawable update callback "<<drawable<<std::endl;
    }
};

struct DrawableCullCallback : public osg::Drawable::CullCallback
{
    /** do customized cull code.*/
    virtual bool cull(osg::NodeVisitor*, osg::Drawable* drawable, osg::State* /*state*/) const
    {
        std::cout<<"Drawable cull callback "<<drawable<<std::endl;
        return false;
    }
};

class InsertCallbacksVisitor : public osg::NodeVisitor
{

   public:

        InsertCallbacksVisitor():osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN)
        {
        }

        virtual void apply(osg::Node& node)
        {
             node.setUpdateCallback(new UpdateCallback());
             node.setCullCallback(new CullCallback());
             traverse(node);
        }

        virtual void apply(osg::Geode& geode)
        {
            geode.setUpdateCallback(new UpdateCallback());

            //note, it makes no sense to attach a cull callback to the node
            //at there are no nodes to traverse below the geode, only
            //drawables, and as such the Cull node callbacks is ignored.
            //If you wish to control the culling of drawables
            //then use a drawable cullback...

            for(unsigned int i=0;i<geode.getNumDrawables();++i)
            {
                geode.getDrawable(i)->setUpdateCallback(new DrawableUpdateCallback());
                geode.getDrawable(i)->setCullCallback(new DrawableCullCallback());
                geode.getDrawable(i)->setDrawCallback(new DrawableDrawCallback());
            }
        }

        virtual void apply(osg::Transform& node)
        {
            apply((osg::Node&)node);
        }
};

class MyReadFileCallback : public osgDB::Registry::ReadFileCallback
{
public:
    virtual osgDB::ReaderWriter::ReadResult readNode(const std::string& fileName, const osgDB::ReaderWriter::Options* options)
    {
        std::cout<<"before readNode"<<std::endl;
        // note when calling the Registry to do the read you have to call readNodeImplementation NOT readNode, as this will
        // cause on infinite recusive loop.
        osgDB::ReaderWriter::ReadResult result = osgDB::Registry::instance()->readNodeImplementation(fileName,options);
        std::cout<<"after readNode"<<std::endl;
        return result;
    }
};

class CameraUpdateCallback : public osg::NodeCallback
{
    virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
    {
        std::cout<<"Camera update callback - pre traverse"<<node<<std::endl;
        traverse(node,nv);
        std::cout<<"Camera update callback - post traverse"<<node<<std::endl;
    }
};

class CameraEventCallback : public osg::NodeCallback
{
    virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
    {
        std::cout<<"Camera event callback - pre traverse"<<node<<std::endl;
        traverse(node,nv);
        std::cout<<"Camera event callback - post traverse"<<node<<std::endl;
    }
};


struct TestDrawableUpdateCallback : public osg::Drawable::UpdateCallback
{
    TestDrawableUpdateCallback(const std::string &message): _message(message) {}

    virtual void update(osg::NodeVisitor*, osg::Drawable* drw) {
        printf("%s\n", _message.c_str());
    }
    std::string _message;
};

struct TestNodeUpdateCallback : public osg::NodeCallback
{
    TestNodeUpdateCallback(const std::string &message): _message(message) {}

    virtual void operator()(osg::Node* node, osg::NodeVisitor* nv) {
        printf("%s\n", _message.c_str());
    }
    std::string _message;
};


int main( int argc, char **argv )
{
    // use an ArgumentParser object to manage the program arguments.
    osg::ArgumentParser arguments(&argc,argv);

    // set the osgDB::Registy read file callback to catch all requests for reading files.
    osgDB::Registry::instance()->setReadFileCallback(new MyReadFileCallback());

    // initialize the viewer.
    osgViewer::Viewer viewer;

    // load the nodes from the commandline arguments.
    osg::ref_ptr<osg::Node> rootnode;

    if (arguments.read("--test"))
    {
        osg::ref_ptr<osg::Group> root = new osg::Group();
        rootnode = root;

        osg::Node *test1 = new osg::Node();
        test1->setUpdateCallback(new TestNodeUpdateCallback("test1"));
        root->addChild(test1);

        osg::Drawable *test2 = new osg::Drawable();
        test2->osg::Node::setUpdateCallback(new TestNodeUpdateCallback("test2"));
        root->addChild(test2);

        osg::Drawable *test3 = new osg::Drawable();
        test3->setUpdateCallback(new TestDrawableUpdateCallback("test3"));
        root->addChild(test3);

        osg::Geode *test4 = new osg::Geode();
        osg::Drawable *drawable1 = new osg::Drawable();
        drawable1->osg::Node::setUpdateCallback(new TestNodeUpdateCallback("test4"));
        test4->addDrawable(drawable1);
        root->addChild(test4);

        osg::Geode *test5 = new osg::Geode();
        osg::Drawable *drawable2 = new osg::Drawable();
        drawable2->setUpdateCallback(new TestDrawableUpdateCallback("test5"));
        test5->addDrawable(drawable2);
        root->addChild(test5);

        osg::Geode *test6 = new osg::Geode();
        osg::Drawable *drawable3 = new osg::Drawable();
        drawable3->setUpdateCallback(new TestDrawableUpdateCallback("test6"));
        test6->addChild(drawable3);
        root->addChild(test6);

        osg::Geode *test7 = new osg::Geode();
        osg::Drawable *drawable4 = new osg::Drawable();
        drawable4->osg::Node::setUpdateCallback(new TestNodeUpdateCallback("test7"));
        test7->addChild(drawable4);
        root->addChild(test7);

        printf("Numchildren with updates %u\n", rootnode->getNumChildrenRequiringUpdateTraversal());

    }
    else
    {
        rootnode = osgDB::readRefNodeFiles(arguments);

        // if not loaded assume no arguments passed in, try use default mode instead.
        if (!rootnode) rootnode = osgDB::readRefNodeFile("cow.osgt");

        if (!rootnode)
        {
            osg::notify(osg::NOTICE)<<"Please specify a file on the command line"<<std::endl;

            return 1;
        }

        // run optimization over the scene graph
        osgUtil::Optimizer optimzer;
        optimzer.optimize(rootnode.get());

        // insert all the callbacks
        InsertCallbacksVisitor icv;
        rootnode->accept(icv);
    }

    viewer.getCamera()->setUpdateCallback(new CameraUpdateCallback());
    viewer.getCamera()->setEventCallback(new CameraEventCallback());

    // set the scene to render
    viewer.setSceneData(rootnode.get());

    viewer.setCameraManipulator(new osgGA::TrackballManipulator);

    viewer.realize();

    while(!viewer.done())
    {
        OSG_NOTICE<<std::endl<<"New Frame"<<std::endl;
        viewer.frame();
    }

    return 0;
}