Rotation matrices were replaced with quaternions but incorrect contructor was used. There was a call to Quat(angle, xAxis, yAxis, zAxis ) but there is no such constructor in Quat class to create quaternion for rotation. As a result we got this values being written into quaternion directly.
I've replaced Quat contructor calls with the ones creating rotation quaternions Quat( angle, Vec3( axis ) )."
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 ...
"
attached):
* Light point strings using the REPLICATE opcode should now be supported
(>=15.6?)
* Directional lights should now work as in Performer using a viewing
frustrum defined by a direction vector, horizontal angular width, vertical
angular width, and roll angle about the direction vector. The current
directional light implementation had some bad assumptions which caused
problems with direction vectors not on the XY plane.
* IVE and OSG reader/writers were updated as appropriate"
