It's now possible to conveniently transform 2D vectors and points with
3x3 matrices and 3D vectors/points with 4x4 matrices. Previous most
low-level solution:
Matrix4 m;
Vector3 v;
Vector3 a = (m*Vector4(v, 1.0f)).xyz();
Vector4 b = (m*Vector4(v, 0.0f)).xyz();
Another, more generalized solution for points was with Point2D/Point3D,
adding a lot of confusion (what is that class and what does .vector()?):
Vector3 a = (m*Point3D(v)).vector();
And the worst solution was with generic 2D/3D code (WTF!):
auto a = (m*typename DimensionTraits::PointType(v)).vector();
Now it is just this, similar for both dimensions:
Vector3 a = m.transformPoint(v);
Vector3 b = m.transformVector(v);
Note that transformation three-component vectors with 3x3 matrices or
four-component vectors with 4x4 matrices is easy enough so it doesn't
need any special convenience functions whatsoever:
Vector3 c = m.rotation()*v;
Was causing improper implicit conversions, such as here (example
directly from unit tests, where it was unintentionally used):
Vector3 normal;
Matrix4 transformation;
auto transformedNormal = transformation*normal;
Not only that it was possible to multiply 4x4 matrix with 3-component
vector, but the resulting type was Point3D which was absolutely
confusing. Currently it must be explicitly converted:
transformedNormal = transformation*Point3D(normal);
Overall architecture is simplififed with this change and also it's not
needed to use reinterpret_cast in matrix internals anymore, thus there
is no need for operator() and [][] works now always as expected without
any risk of GCC misoptimizations.
On the other side, constructing matrix from list of elements is not
possible anymore. You have to specify the elements as list of
column vectors, which might be less convenient to write, but it helps to
distinguish what is column and what is row:
Matrix<2, int> a(1, 2, // before
3, 4);
Matrix<2, int> a(Vector<2, int>(1, 2), // now
Vector<2, int>(3, 4));
For some matrix specializations (i.e. Matrix3 and Matrix4) it is
possible to use list-initialization instead of explicit type
specification:
Matrix<3, int>({1, 2, 3},
{4, 5, 6},
{7, 8, 9});
I didn't yet figure out how to properly implement the general
(constexpr) constructor to also take lists, so it's a bit ugly for now.
Matrix operations are now done column-wise, which should help with
future SIMD implementations, documentation is also updated accordingly.
I also removed forgotten remains of matrix/matrix operator*=(), which
can be confusing, as the multiplication is not commutative. Why it is
not present is explained in d9c900f076.
Long-standing TODO, can be used for in-game mirrors etc. I give up with
shearing, as I think that it makes sense only in 2D and I can't find any
reasonable use case for that yet.
Removing of another <*stream> #include leads to more compilation time
saving, now from ~5:12 to ~4:55. Another compilation time improvements
will now be possible only by using Clang's modules, I don't know where
to optimize further (except for getting rid of <sstream> in tests).
Magnum.h now doesn't include anything except OpenGL headers, thus
changes in Math library don't trigger recompilation of everything, but
only of things really depending on it.
Math constants moved to separate file for similar reasons, de-inlined
some functions to remove the need for some #includes.
Now we can use CORRADE_COMPARE() almost exclusively for comparing
Vector, Matrix instances and all containers from STL. Tests running time
for all 31 tests is now around 0.1 sec instead of two seconds like
before.
Disabled compilation of all benchmarks, because TestSuite cannot handle
them yet.
PKGBUILD from AUR now can shamelessly use check() function without
unnecessary dependencies.
Vladimír Vondruš