Sometimes it's desirable to just make a mesh indexed unconditionally,
which wasn't really possible with this thing, and having to special-case
that at the call site is very annoying. Now it makes a mesh
trivially indexed if it has any other primitive than the ones listed,
and if it's already indexed, it's just passed through.
Using Containers::Pair allows me to make certain Range APIs constexpr
that weren't possible in C++11 before. Compared to std::pair it's also
trivially copyable, which is a nice property when storing it in various
growable containers.
As usual, the <Corrade/Containers/PairStl.h> include is in place to help
people with porting, although in many cases this change will be
breaking. I had to do it at some point anyway, so the earlier it is the
better.
Not that C++ STL and exceptions would be anything to take inspiration
from, but there's std::out_of_range. Python IndexError is also specified
as "index out of range", not "bounds".
Partially needed to avoid build breakages because Corrade itself
switched as well, partially because a cleanup is always good. Done
except for (STL-heavy) code that's deprecated or SceneGraph-related APIs
that are still quite full of STL as well.
With the workarounds moved to the GL::Shader class itself, it's just a
complicated wrapper for adding the compatibility.glsl file and a rather
strange way to define a file-local helper for resource import on static
builds. Do that directly instead.
While extremely easy to do with the linear lookup, I bet it'd be
something utterly complex like trying to hash a std::pair with the
original hashmap-based implementation.
Let's guess what would be faster -- making a ton of tiny allocations,
hashing a bunch of numbers in a very complex way and then jumping
through all those indirections and cache misses of a multimap linked
list for each and every attribute of each mesh, OR going linearly
through a two tiny arrays for every mesh? I don't have any benchmarks
ready but I bet the latter will win.
Building a mesh from scratch makes the test much easier to grasp and
allows me to test more corner cases together instead of having to add
special cases for offset-only, array and implementation-specific
attributes.
The test now also uncovers a potential optimization opportunity where a
copy of the attribute metadata could be avoided in some cases. Not
implementing it right now, just adding a TODO and an XFAIL.
A bit sad it took me three years to invent the right name for this
utility, heh. Also moving it together with others to a new
MeshTools/Copy.h header because *this* is the mainly useful API, not
reference() / mutableReference().
MaterialTools and SceneTools will get similar copy() APIs doing the same
thing.