OpenSceneGraph/examples/osgkdtree/osgkdtree.cpp
Robert Osfield dd996a3289 Introduced CMake option OSG_PROVIDE_READFILE option that defaults to ON, but when switched to OFF disables the building of the osgDB::read*File() methods,
forcing users to use osgDB::readRef*File() methods.  The later is preferable as it closes a potential threading bug when using paging databases in conjunction
with the osgDB::Registry Object Cache.  This threading bug occurs when one thread gets an object from the Cache via an osgDB::read*File() call where only
a pointer to the object is passed back, so taking a reference to the object is delayed till it gets reassigned to a ref_ptr<>, but at the same time another
thread calls a flush of the Object Cache deleting this object as it's referenceCount is now zero.  Using osgDB::readREf*File() makes sure the a ref_ptr<> is
passed back and the referenceCount never goes to zero.

To ensure the OSG builds when OSG_PROVIDE_READFILE is to OFF the many cases of osgDB::read*File() usage had to be replaced with a ref_ptr<> osgDB::readRef*File()
usage.  The avoid this change causing lots of other client code to be rewritten to handle the use of ref_ptr<> in place of C pointer I introduced a serious of
templte methods in various class to adapt ref_ptr<> to the underly C pointer to be passed to old OSG API's, example of this is found in include/osg/Group:

    bool addChild(Node* child); // old method which can only be used with a Node*

    tempalte<class T> bool addChild(const osg::ref_ptr<T>& child) { return addChild(child.get()); } // adapter template method

These changes together cover 149 modified files, so it's a large submission. This extent of changes are warrent to make use of the Object Cache
and multi-threaded loaded more robust.



git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@15164 16af8721-9629-0410-8352-f15c8da7e697
2015-10-22 13:42:19 +00:00

71 lines
2.2 KiB
C++

/* OpenSceneGraph example, osgintersection.
*
* 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 <osgDB/ReadFile>
#include <osg/ArgumentParser>
#include <osg/ApplicationUsage>
#include <osg/Timer>
#include <osg/CoordinateSystemNode>
#include <osg/Notify>
#include <osg/io_utils>
#include <osg/Geometry>
#include <osg/TriangleIndexFunctor>
#include <osgUtil/IntersectionVisitor>
#include <osgUtil/LineSegmentIntersector>
#include <osgUtil/UpdateVisitor>
#include <osgSim/LineOfSight>
#include <osgSim/HeightAboveTerrain>
#include <osgSim/ElevationSlice>
#include <osgViewer/Viewer>
#include <osg/KdTree>
#include <iostream>
int main(int argc, char **argv)
{
// use an ArgumentParser object to manage the program arguments.
osg::ArgumentParser arguments(&argc,argv);
int maxNumLevels = 16;
int targetNumIndicesPerLeaf = 16;
while (arguments.read("--max", maxNumLevels)) {}
while (arguments.read("--leaf", targetNumIndicesPerLeaf)) {}
osgDB::Registry::instance()->setBuildKdTreesHint(osgDB::ReaderWriter::Options::BUILD_KDTREES);
osg::ref_ptr<osg::Node> scene = osgDB::readRefNodeFiles(arguments);
if (!scene)
{
std::cout<<"No model loaded, please specify a valid model on the command line."<<std::endl;
return 0;
}
osgViewer::Viewer viewer;
viewer.setSceneData(scene);
return viewer.run();
}