Same as done for Containers::StaticArray some time ago. Since it's not a
potentially dangerous operation, it's not made as an overload of the
from() function, but instead a regular constructor. It's however kept
explicit for now, even though it eventually might not need to be -- I'm
not sure about potential consequences yet.
Need to make a constexpr style data for the UI library and it involves
various multiplications and such, so took that as an opportunity to
enable constexpr on all operators. No other functions such as max() so
far, as I don't really need those yet.
After a few abandoned iterations that involved adding constexpr
overloads only to the Vector2, Vector3 and Vector4 subclasses I ended up
with a rather minimal solution that makes the base Vector constexpr
already, and just about 50 extra lines in total.
In the original code from 2010, to avoid redundant code, the const
operations were delegating to compound assignment operations, i.e.
operator*() being implemented by making a copy of itself and then
delegating to operator*=(). Thus, as far as a Debug build is concerned,
one extra indirection for each. The new solution is *also* one
indirection (which is needed in order to expand the variadic sequence)
so it's not worse in Debug in any way, however it's one indirection less
in the Vector2, Vector3 and Vector4 subclasses as there it delegates
directly to the internal implementation instead of the base class
operator. On GCC at least, there's no measurable impact on build times
either -- the whole project builds in ~2:22 both before and after this
change.
The way the change is done also allows the new code to be compiled out
if C++14 constexpr is enabled, where the functions would simply delegate
to the compound assignments. I'm not planning to touch that any time
soon either.
This complier is making my hair gray. Fortunately the out-of-class
operator doesn't conflict with the in-class one, so it's purely an
additive workaround. Adding extra checks to all subclasses to be sure
this works correctly in all cases and not just in the base class.
Instead of defining the same types and vaguely risking little
differences. Typedefs that don't exist in Magnum.h (such as integer
quaternions) and typedefs that differ from Magnum.h (such as
using Vector<4, T> instead of Vector4<T>) stay as typedefs, to make it
clear what *deliberately* differs and what not.
Typedefs that didn't conflict with the template types in Math (such as
Vector3us) are removed entirely, as the typedef from Magnum.h can be
used directly in that case, without any `using`.
I did this back in 2010 because it "felt like the right thing to do",
given that all of Magnum depended on Math and not vice versa. But,
strictly speaking, Math already uses typedefs from Magnum/Types.h so why
it couldn't also bring in the Corrade namespace, and the
Debug/Warning/Error names too. Having to type out Corrade:: in all these
was really just a waste of time, weird inconsistency in docs and an
extra roadblock for whoever might want to contribute anything there.
Certain Clang-based IDEs (CLion) "emulate" a compiler by inheriting all
its defines, which means one gets __clang__ defined but also __GNUC__
set to 11 or whatever, breaking all these assumptions.
The old one is deprecated, and will be removed in a future release.
Unfortunately, to avoid deprecation warnings, all use of NoInit in the
Math library temporarily have to be Magnum::NoInit This will be cleaned
up when the deprecated alias is removed.
And the Vector3 version 5% slower in Release, on GCC at least. FFS,
what was I thinking with the gather() things. Nice in user code,
extremely bad in library code.
I don't know why, but marking the output of copy constructor of any
subclass or output of conversion operator of any class as constexpr
causes MSVC to complain about non-constant expression.
Probably just another bug.
Useful for squeezing out last bits of performance, e.g. in this case:
Vector3 a;
a[0] = something++;
a[1] = something++;
a[2] = something++;
In the code all elements are first zeroed out and then overwritten
later, thus it might be good to avoid the zero-initialization:
Vector3 a{Math::NoInit};
a[0] = something++;
a[1] = something++;
a[2] = something++;
This will of course be more useful in far larger data types and arrays
of these.
Some classes are by default constructed zero-filled while other are set
to identity and the only way to to check this is to look into the
documentation. This changes the default constructor of all classes to
take an optional "tag" which acts as documentation about how the type is
constructed. Note that this result in no behavioral changes, just
ability to be more explicit when writing the code. Example:
// These two are equivalent
Quaternion q1;
Quaternion q2{Math::IdentityInit};
// These two are equivalent
Vector4 vec1;
Vector4 vec2{Math::ZeroInit};
Matrix4 a{Math::IdentityInit, 2}; // 2 on diagonal
Matrix4 b{Math::ZeroInit}; // all zero
This functionality was already present in some ugly form in Matrix,
Matrix3 and Matrix4 classes. It was long and ugly to write, so it is
now generalized into the new Math::IdentityInit and Math::ZeroInit tags,
the original Matrix::IdentityType, Matrix::Identity, Matrix::ZeroType
and Matrix::Zero are deprecated and will be removed in the future
release.
Math::Matrix<7, Int> m{Math::Matrix<7, Int>::Identity}; // before
Math::Matrix<7, Int> m{Math::IdentityInit}; // now
It is often annoying to write e.g. this, especially in generic code:
T dot = Math::Vector<size, T>::dot(a, b);
When this is more than enough and the compiler can infer the rest from
the context:
T dot = Math::dot(a, b);
There are more downsides and confusing cases (you can call
Math::Vector<3, T>::dot(), Math::Vector3<T>::dot() and Color3::dot() and
it is still the same function), so I made these as free functions in
Math namespace. You can now also abuse ADL for the calls, but I would
advise against that for better readability:
T d = dot(a, b); // dot?! what on earth is dot? and what is a?
The only downside found when porting is that you need to specify the
type somehow when having both parameters as initializer lists:
T d = dot({2.0f, -1.5f}, {1.0f, 2.5f}); // error
T d = dot(Complex{2.0f, -1.5f}, {1.0f, 2.5f}); // okay
But that's probably reasonable (and it's also highly corner case,
the functions were used this way only in tests).
The original static member functions are of course still present, but
marked as deprecated and will be removed at some point in future.
The only places where they aren't absolute are:
- when header is included from corresponding source file
- when including headers which are not part of final installation (e.g.
test-specific configuration, headers from Implementation/)
Everything what was in src/ is now in src/Corrade, everything from
src/Plugins is now in src/MagnumPlugins, everything from external/ is in
src/MagnumExternal. Added new CMakeLists.txt file and updated the other
ones for the moves, no other change was made. If MAGNUM_BUILD_DEPRECATED
is set, everything compiles and installs like previously except for the
plugins, which are now in MagnumPlugins and not in Magnum/Plugins.
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.
Vladimír Vondruš