The better accuracy is for specific cases (90 degree rotations around a
main axis: the matrix element for that axis is now 1 instead of
0.99999994). The speedup comes from doing fewer additions (multiply
seems to be faster than add for fp, at least in this situation).
After messing with SIMD stuff for a little, I think I now understand why
the industry went with xyzw instead of the mathematical wxyz. Anyway, this
will make for less pain in the future (assuming I got everything).
The idea comes from The OpenGL Shader Wrangler
(http://prideout.net/blog/?p=11). Text files are broken up into chunks via
lines beginning with -- (^-- in regex). The chunks are optionally named
with tags of the form: [0-9A-Za-z._]+. Unnamed chunks cannot be found.
Searching for chunks looks for the longest tag that matches the beginning
of the search tag (eg, a chunk named "Vertex" will be found with a search
tag of "Vertex.foo"). Note that '.' forms the units for the searc
("Vertex.foo" will not find "Vertex.f").
Unlike glsw, this implementation does not have the concept of effects keys
as that will be separate. Also, this implementation takes strings rather
than file names (thus is more generally useful).
set_bits_t is now 64 bits for x86_64 machines (in linux, anyway). This gave
qfvis a huge speed boost: from ~815s to ~720s.
Also, expose some of the set internals so custom set operators can be
created.
Now we can get tight (<1e-6 * radius_squared error) bounding spheres. More
importantly (for qfvis, anyway) very quickly: 1.7Mspheres/second for a 5
point cloud on my 2.33GHz Core 2 :)
It "works" for lines, triangles and tetrahedrons. For lines and triangles,
it gives the barycentric coordinates of the perpendicular projection of the
point onto to features. Only tetrahedrons are guaranteed to reproduce the
original point.
Getting everything right with an enum proved to be too difficult if not
impossible. Also use better tests for equivalence and intersection.
Many more tests have been added. All pass :)
And the tests really exercised VectorShear (first attempt had things
messed up when more than one shear value was non-zero). Also,
Mat4Decompose wasn't orthogonalizing the z axis row. Oops. Anyway,
Mat4Decompose is now known to work well, and the usage of its output is
understood :)
I got the idea from blender when I discovered by accident that quat * vect
produces the same result as quat * qvect * quat* and looked up the code to
check what was going on. While matrix/vector multiplication still beats the
pants off quaternion/vector multiplication, QuatMultVec is a slight
optimization over quat * qvect * quat* (17+,24* vs 24+,32*, plus no need to
to generate quat*).
Buffer underflow and though strcpy has always been safe there, change to
memmove. Had the added benefit of helping me create more test cases for
better coverage.
