This finally makes it possible to expose APIs that take StridedArrayView
instances as an input, until now the type information was always lost,
making all views plain bytes and thus impossible to check whether the
types passed were a large enough size at least, if nothing else.
Preserving the type means there has to be type-dependent implementation
for __getitem__() and __setitem__(). So far this is only done for the
very basic builtin types, similarly to what Python's own array supports.
In the buffer protocol it used to advertise untyped data with B as the
format string, but the __getitem__ and __setitem__ were using the char
type (implicitly coming from the fact that the type exposed is
ArrayView<char>, StridedArrayViewND<char> or their const variants),
resulting in the data being treated as characters by Python. Which
was extremely annoying and inconsistent with how the bytes and bytearray
behaves.
Now ArrayView bindings always operate with std::uint8_t, and for
StridedArrayView there's a special case for the <char> type, which makes
it treated as std::uint8_t as well. Furthermore, to hint that the <char>
is "general data", the format string for it is null / None instead of B.
If enabled, this causes sys.setdlopenflags() being called with
RTLD_GLOBAL before the native Corrade module is loaded, in a hope to
resolve recurring nightmares with static Corrade and Magnum libraries
being linked into multiple dynamic modules.
Originally those were assertions that were kept even in release builds,
which meant that calling math.angle() on non-normalized vectors aborted
the whole Python interpreted. Not great. But then the assertions were
made debug-only, which means invalid usage from Python (where the
bindings are usually only built as Release) now silently gives back a
wrong result, which is perhaps even worse.
Because the Python overhead is already massive due to all string lookup
and such, doing one more check in the implementations isn't really going
to slow down anything. Thus I'm mirroring all (debug-only) Magnum
assertions on the Python side, turning them into exceptions. With proper
messages as well, because those are extremely useful.
Breaking changes, sorry. Also remade the SceneTools hierarchy test to
not be that much redundant -- the name- and ID-based overloads can be
tested together.
Changed those to be IndexError instead of ValueError, since those are
indexing dimensions. Plus added a new check for broadcasted dimension
size as otherwise it'd blow up on a C++ assert.
This is important in case the data aren't owned by the instance but
instead referencing something else, for example the importer, a
memory-mapped file or another instance. Will get increasingly
important for zero-copy data import.
Right now the importer/converter APIs are not checked against the
features so using them wrong will assert and make Python die. But there
are at least the enums exposed now so it's possible to prevent the
assert.
They should be named after the plural EnumSet, not the C++ enum. That
was already done for the enums in the primitives library as well as all
shader flags, but not here. They should all also contain a NONE value
for an empty set.
Breaking change, sorry. To avoid similar mistakes in the future, this is
now documented in the API Conventions page.
Vladimír Vondruš