set.
The optimization is based on the observation that matrix matrix multiplication
with a dense matrix 4x4 is 4^3 Operations whereas multiplication with a
transform, or scale matrix is only 4^2 operations. Which is a gain of a
*FACTOR*4* for these special cases.
The change implements these special cases, provides a unit test for these
implementation and converts uses of the expensiver dense matrix matrix
routine with the specialized versions.
Depending on the transform nodes in the scenegraph this change gives a
noticable improovement.
For example the osgforest code using the MatrixTransform is about 20% slower
than the same codepath using the PositionAttitudeTransform instead of the
MatrixTransform with this patch applied.
If I remember right, the sse type optimizations did *not* provide a factor 4
improovement. Also these changes are totally independent of any cpu or
instruction set architecture. So I would prefer to have this current kind of
change instead of some hand coded and cpu dependent assembly stuff. If we
need that hand tuned stuff, these can go on top of this changes which must
provide than hand optimized additional variants for the specialized versions
to give a even better result in the end.
An other change included here is a change to rotation matrix from quaterion
code. There is a sqrt call which couold be optimized away. Since we divide in
effect by sqrt(length)*sqrt(length) which is just length ...
"
they are written to disk, either inline or as an external file. Added support for
this in the .ive plugin. Default of WriteHint is NO_PREFERNCE, in which case it's
up to the reader/writer to decide.
"I made several modifications:
* The cause of my errors was that my OSG source directory path contains spaces. To fix this issue I wrapped all paths with quotes, as stated in doxygen documentation.
* I also received some warning messages about deprecated doxygen settings, which I fixed by updating the doxygen file, i.e. running \u2018doxygen \u2013u doxygen.cmake\u2018. By running this command deprecated doxygen options are removed, some option comments have changed and quite some options have been added (I kept their default settings unless mentioned).
* I was surprised to find that the doxygen OUTPUT_DIRECTORY was set to \u201c${OpenSceneGraph_SOURCE_DIR}/doc\u201d, which does not seem appropriate for out of source builds; I changed this to \u201c${OpenSceneGraph_BINARY_DIR}/doc\u201d. (On the other hand, maybe a cmake selectable option should be given to the user?)
* Fixed two warnings I received about unexpected end-of-list-markers in \u2018osg\AnimationPath and \u2018osgUtil\CullVisitor due to excess trailing points in comments.
* Fixed a warning in osgWidget\StyleInterface due to an #include directive (strangely) placed inside a namespace.
* Fixed a warning in osg\Camera due to the META_Object macro that confused doxygen. Adding a semi-colon fixed this.
* Removed auto_Mainpage from the INCLUDE option, because I am positive that this file does not belong there; It never generated useful documentation anyway.
* I added the OSG version number environment variable to the PROJECT_NUMBER option so that the version number is now shown on the main page of generated documentation (e.g. index.html).
* Changed option FULL_PATH_NAMES to YES, but made sure STRIP_FROM_PATH stripped the absolute path until the include dir. This fixed an issue that created mangled names for identical filenames in different directories. E.g. osg/Export and osgDB/Export are now correctly named.
* Changed option SHOW_DIRECTORIES to yes, which is a case of preference I guess.
"
New attribute DatabasePager::_expiryFrames sets number of frames a PagedLOD child is kept in memory. The attribute is set with DatabasePager::setExpiryFrames method or OSG_EXPIRY_FRAMES environmental variable.
New attribute PagedLOD::PerRangeData::_
frameNumber contains frame number of last cull traversal.
Children of PagedLOD are expired when time _AND_ number of frames since last cull traversal exceed OSG_EXPIRY_DELAY _AND_ OSG_EXPIRY_FRAMES respectively. By default OSG_EXPIRY_FRAMES = 1 which means that nodes from last cull/rendering
traversal will not be expired even if last cull time exceeds OSG_EXPIRY_DELAY. Setting OSG_EXPIRY_FRAMES = 0 revokes previous behaviour of PagedLOD.
Setting OSG_EXPIRY_FRAMES > 0 fixes problems of children reloading in lazy rendering applications. Required behaviour is achieved by manipulating OSG_EXPIRY_DELAY and OSG_EXPIRY_FRAMES together.
Two interface changes are made:
DatabasePager::updateSceneGraph(double currentFrameTime) is replaced by DatabasePager::updateSceneGraph(const osg::FrameStamp &frameStamp). The previous method is in #if 0 clause in the header file. Robert, decide if You want to include it.
PagedLOD::removeExpiredChildren(double expiryTime, NodeList &removedChildren) is deprecated (warning is printed), when subclassing use PagedLOD::removeExpiredChildren(double expiryTime, int expiryFrame, NodeList &removedChildren) instead. "
