No Vector<size, T> and std::initializer_list versions yet, as the
algorithm for it is pretty complicated and I'm not sure that they will
be used frequently enough to deserve their existence.
There are more cases that should be fixed, but this is the most
problematic one, as this might look completely innocent:
Vector2 a, b;
float* c = (a + b).data();
Unlike this, which looks suspicious:
Vector2& c = a + b;
Operators that are part of Vector are operating only with the same type
as Vector itself, operators for multiplying/dividing integral vectors
with floating-point numbers and vectors are now out-of-class and enabled
only for integer vectors. It allows better control (e.g. multiplying
integer and floating-point vector will _always_ result in floating-point
one). Thoroughly tested integer/FP operations and also reworked and
tested operator and funciton reimplementations in subclasses, both for
value correctness and result type correctness.
Also fixed unary RectangularMatrix::operator-() and Vector::operator-()
documentation (was stating that the operation is done in-place, which is
impossible.
First, removed functions which can be done with Vector's member
functions and functions from Functions.h. More flexibility and less
redundant code which leads to easier SIMD implementation later.
Vector4 a;
Float b = a.maxAbs(); // before
Float b = Math::abs(a).max(); // now
Second, removed all functions from RectangularMatrix which are
implemented in Vector and added conversion from RectangularMatrix to
Vector and back. Also for more flexibility and less redundant code (i.e.
reusing SIMD-optimized Vector::max() instead of writing it again).
Matrix4x3 a;
Float b = a.max(); // before
Float b = a.toVector().max(); // now
Comparing squared length to 1 is not sufficient to compare within range
[1 - epsilon, 1 + epsilon], as e.g. Quaternion with dot() = 1 + 1e-7
when converted to matrix has column vectors with dot() = 1 + 1e-6, which
is just above 1 + epsilon. Thus it's needed to compare sqrt(dot()) in
range [1 - epsilon, 1 + epsilon] or dot() in range [1 - 2*epsilon +
epsilon^2, 1 + 2*epsilon + epsilon^2]. Because epsilon^2 is way off
machine precision, it's omitted, thus dot() in all isNormalized()
implementations is now compared this way:
abs(dot() - 1) < 2*epsilon;
As there is no Magnum::TypeTraits struct anymore, there is no need to
have redundant name in it. Hopefully Doxygen will handle the difference
between this and Corrade's TypeTraits.h properly.
Square matrices already had that, (dual) quaternions too, making that
the default also with complex numbers. Updated the documentation to
reflect that.
It is now possible to implicitly create one-element Vector and also
explicitly fill more-element Vector with one value without any ambiguous
overload conflicts:
Vector<1, int> a1 = 1; // calls implicit constructor
//Vector<3, int> a3 = 1; // error!
Vector<1, int> b1(1); // still calls the implicit constructor, the
// explicit is disabled for one-element vector
Vector<3, int> b3(1); // calls the explicit "filling" constructor,
// the implicit is disabled for only one argument
The downside of this is that now specifying improper element count in
constructor doesn't lead to static_assert with human readable error, but
rather cryptic "no match" error.
The comparisons have also SIMD instructions returning bool vector, this
future-proofs them. Also it isn't confusing anymore (a < b is true when
all are less or just one?).
Also updated all dependent classes to follow the change, such as Color
and Rectangle. Backwards compatibility for GCC 4.6 (with lack of support
for delegating constructors) will be done as non-constexpr constructor
using operator=().
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.
Vladimír Vondruš