// A custom class
namespace CustomDomain {
class MyGroup : public osg::Group
{
public:
META_Node( CustomDomain, MyGroup );
void setMyName( const std::string& n );
const std::string& getMyName() const;
void setMyID( int id );
int getMyID() const;
...
};
}
// The serialization wrapper using a custom domain name
REGISTER_CUSTOM_OBJECT_WRAPPER( MyDomain,
CustomDomain_MyGroup,
new CustomDomain::MyGroup,
CustomDomain::MyGroup,
"osg::Object osg::Node osg::Group CustomDomain::MyGroup" )
{
ADD_STRING_SERIALIZER( MyName, std::string() );
{
UPDATE_TO_VERSION_SCOPED( 1 ); // Updated for a new domain version
ADD_INT_SERIALIZER( MyID, 0 );
}
}
Save the class instance as follows:
osgDB::writeNodeFile( *myGroup, "serializer_test.osgt", new osgDB::Options("CustomDomains=MyDomain:1") );
The output file will include the domain version definition and all the class data, and can be read back. We can also force setting the domain version by the CustomDomains option while reading the saved files. If we save the class instance without any options, MyID will be ignored because the default domain version is 0.
This may help third-party libraries like osgEarth to maintain their own serializers without regarding to the OSG soversion changes.
Another feature added is a more robust binary format, which in fact adds a size-offset at each block's beginning. When there are problems or unsupported data types while reading, we can now directly jump to the block end indicated by the offset value. So a .osgb file will automatically ignore bad data and read remains as normal (at present it will fail at all). This feature will not break the backward compatibility, and can be disabled by setting "RobustBinaryFormat=false" while writing out.
Hope these changes can work smoothly with present and future community projects. Maybe we should also consider have an osgserializer example to test and demonstrate all things we can do now."
using osgDB::XmlParser. The extension for XML-formatted scenes is
.osgx, corresponding to .osgb for binary and .osgt for ascii. It could
either be rendered in osgviewer or edited by common web browsers and
xml editors because of a range of changes to fit the XML syntax. For
example, the recorded class names are slight modified, from
'osg::Geode' to 'osg--Geode'.
To quickly get an XML file:
# ./osgconv cow.osg cow.osgx
The StreamOperator header, InputStreram and OutputStream classes are
modified to be more portable for triple ascii/binary/XML formats. I
also fixed a bug in readImage()/writeImage() to share image objects if
needed.
The ReaderWriterOSG2 class now supports all three formats and
reading/writing scene objects (not nodes or images), thanks to
Torben's advice before.
"
1. Rewrite the reading/writing exception handlers to work like the ive
plugin exceptions.
2. Write a header writing/checking function in ReaderWriterOSG2.cpp,
which may help decide if the stream is ascii or binary. The
readInputIterator() function will return null pointer if the input
file is nither osgb nor osgt format, which indicates that the old .osg
format could be used here, in case we've merged the two plugins
together.
3. Add a new ForceReadingImage option in the InputStream, which will
allocate an empty image object with the filename if specifed external
image file is missed. It may be useful for format converting in some
cases.
4. Add new osgParticle wrappers, as well as some modification to the
osgParticle headers, for instance, change isEnabled() to getEnabled().
5. Some fixes to the osg serialization wrappers."
