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 ...
"
the matrix.getRotate() function when a matrix contains a scale as well
as a rotation.
The scale can optionally be switched off, see the top of
testQuatFromMatrix().
As expected, all the current methods for mat to quat conversion fail
these new tests. When the scale is omitted, mk2 of getRotate with sign
instead of signOrZero passes, as well as mk1.
"
"Attached is a patch allows access access to the CMake MACOSX_BUNDLE
option. Now SETUP_APPLICATION and SETUP_EXAMPLE take an additional
optional parameter that specifies if the program is a command line
application or a GUI application (think: IS_COMMANDLINE_APP). Passing
1 means true (is_commandline_app). Passing 0 or omitting the parameter
means false.
I changed the scripts for osgversion and osgunittests to support this
option because I believe they are command line apps. Are there any
others?"
From Robert Osfield, modes to osg::Quat to keep the original implmentation around
as makeRotate_original(,) and added tests into osgunittest to test the new
methods provide equivilant results to the original implemementation. The
orignal implementation will be removed once the new method is more widely tested.
