Consistently with checkLink(), this avoids having to explicitly include
both Iterable and Reference in shader code. Alsod allowing people to
have direct arrays of shaders, runtime-sized lists of shaders etc.
A compat include is provided on a deprecated build to avoid breaking
existing code.
There's no reason for those to exist anymore -- origiinally they were
added in a hopeful attempt to make use of parallel shader compilation,
but in practice that meant compiling at most two or three shaders at
once and still stalling until that was done, so not that great at all.
The new APIs provide much better opportunities for parallelism.
Fun fact:
CORRADE_INTERNAL_ASSERT_OUTPUT(vert.compile() && frag.compile());
is actually one character shorter than
CORRADE_INTERNAL_ASSERT_OUTPUT(GL::Shader::compile({vert, frag}));
so not even typing convenience would be a reason to keep these.
The new async APIs were just checking the link status, and printing the
linker error. Because drivers commonly do all that in a single step,
without really separating compilation from linking (or at least that's
what I thought?), I assumed the linker error would contain *also* the
compilation error, if any.
But on a quick check with Mesa that's not the case, I only get "error:
linking with uncompiled/unspecialized shader", which is very useless.
Which means, to get proper error output, the checkLink() function now
explicitly takes a list of the input shaders. It will unconditionally go
through them at the beginning and call checkCompile() on each.
To further encourage the shaders to be passed, there's no default
argument -- so if the application calls checkCompile() on its own for
some reason, it has to pass an empty list to checkLink().
Until now it relied on the driver adding a \n after each message. Which
happened in 99% cases, but sometimes not, and it is really annoying in
that case. Right now I witnessed Mesa giving me a non-newlined message
if I call checkLink() and a shader compilation failed before, resulting
in nasty output like
error: linking with uncompiled/unspecialized shaderAssertion checkLink() failed at /home/mosra/Code/magnum/src/Magnum/Shaders/FlatGL.cpp:248
And I bet I encountered other weird cases, like there being two
newlines, or the message being just a newline without any other content,
thus spamming the output on every compilation. It's not practical to try
to find driver-specific workarounds here, so I'm just trimming always
and then rely on Debug adding its own newline after.
All the tests were updated to explicitly check that non-null-terminated
strings get handled properly (the GL label APIs have an explicit size,
so it *should*, but just in case). Also, because various subclasses
override the setter to return correct type for method chaining and the
override has to be deinlined to avoid relying on a StringView include,
the tests are now explicitly done for each leaf class, instead of the
subclass
The <string> being removed from the base class for all GL objects may
affect downstream projects which relied on it being included. In case of
Magnum, the breakages were already fixed in the previous commit.
Compile time improvement for the MagnumGL library alone is 0.2 second or
4% (6.1 seconds before, 5.9 after). Not bad, given that there's three
more files to compile and strings are still heavily used in other GL
debug output APIs and all shader stuff. For a build of just the GL
library and all tests, it goes down from 28.9 seconds to 28.1. Most
tests also still rely quite heavily on std::stringstream for debug
output testing, so the numbers still could go further.
Yes, this is only ever provided by an ANGLE extension, and as you might
have guessed, The Great Google Overlords didn't bother caring to have
this supported outside of their browser.
Since the main point of the low-level API is to make use of the
EXT_multi_draw_arrays / ANGLE_multi_draw / WEBGL_multi_draw extensions
for a reduced driver overhead *and* the builtin gl_DrawID variable, it
just doesn't make sense to provide a fallback to draw() in a loop. When
the extensions are not available, the user has to do extra work in order
to supply proper UBO draw offset for each draw call, and thus the
fallback path has basically no practical use.
On the other hand, draw() taking the MeshView instances is kept as-is --
this one is rather old and so breaking compatibility would be an
unnecessary pain point. Plus, since it has to allocate the contiguous
arrays internally, it's not desirable for any fast-path rendering
anyway.
Because a MeshView might not be the best thing to have when you are
submitting a batch of thousand draws. It takes a strided array views to
allow for more flexibility, but can also detect if the input is already
contiguous and use it as-is.
UNFORTUNATELY the GL 1.0 legacy still continues to stink and so there
has to be a 64-bit-specific overload which is the *actual* variant that
doesn't allocate because glMultiDrawElements takes a `void**` for INDEX
OFFSETS and it's IN BYTES! Which foolish soul designed such a thing back
in the 1860s, I wonder. There's no reason to not have an index offset
in elements because all indices have to have the same type ANYWAY. And
yes, I wasted about three hours debugging driver crashes because I
THOUGHT this parameter takes offset in elements, not bytes.
Also note: on 32-bit platforms this depends on latest Corrade with the
CORRADE_TARGET_32BIT definition. Spent an embarrassing amount of time
wondering why all local builds but Emscripten work.
There are no SSO / DSA extensions on that platform, so it doesn't make
sense to do this extra indirection. Saves another kilobyte (237 -> 236
kB) in WebGL 2 magnum-gl-info.wasm.
Instead of wrapping glProgramUniform*() inside a member function, we now
call that function directly, which allows us to remove 2/3rds of
AbstractShaderProgram members. The non-DSA code path is still
implemented though member functions, though they are now static,
mimic the signature of the DSA APIs and do a use() + glUniform*()
internally.
This means that instead of 12 separate allocations we have just one,
allocating everything together in a contiguous piece of memory. That
should be also a bit more cache friendly when accessing the state as
it's not scattered around the memory like crazy.
Because there are no Pointer indirections needed anymore, the State
members are just references now. That resulted in a lot of sweeping
changes around the whole GL library, but they're all trivial, changing
`->` to `.`, mostly.
There's two more nested allocations in the TextureState struct, will
take care of them in a separate commit.
This was done silently until now and I think such platform-specific code
should be always exposed as a disableable workaround. Moreover, I need a
similar thing for ANGLE, so this comes handy.
As usual, the old APIs are still present, but marked as deprecated.
Existing code is not updated yet to ensure I didn't break anything with
this.
This way it's much more intuitive and makes the code shorter and nicer
in many cases. Shaders are now also able to hide irrelevant
draw/dispatch APIs to avoid accidents.
What's left is *a lot* of places taking monstrous
std::vector<std::reference_wrapper> and that can't be changed to
std::vector<Containers::Reference> in a source-compatible way. Even that
would be only a temporary change, since the goal is to fully avoid
dependency on STL in those cases.
The final version of these APIs should take
Containers::ArrayView<Containers::Reference> and be implicitly
convertible froom e.g. std::vector<Containers::Reference>. That's
definitely possible, but not in time for 2019.01, so instead of forcing
users to temporary pass a `{vec.begin(), vec.size()}` everywhere instead
of just `vec`, I'm rather keeping these APIs intact.
Was Magnum::GL::Extensions::GL before and the redundancy was completely
unnecessary. Potential future extensions coming from GLX, EGL or whatnot
will most probably be in the Platform namespace in a completely separate
file, so this is not a problem.
All code internal to the GL library is affected, not much the outside,
as that is handled by the compatibility alias.
At the moment just the GL library itself w/o the tests, and without
backwards compatibility aliases. The following types were left in the
root namespace, despite being in the GL/ directory, as they will get
moved back soon:
* Image, CompressedImage and their dimensional typedefs
* ImageView, CompressedImageView and their dimensional typedefs
* PixelStorage
Not PixelFormat etc., that one will stay in the GL namespace and a
completely new PixelFormat enum will be provided in the root namespace.
Minimal updates (just the include guards) so Git is hopefully able to
detect the rename and track the history properly.
Everything except Magnum::GL doesn't compile now.
On Windows NVidia drivers the glTransformFeedbackVaryings() does not
make a copy of its char* arguments so it fails at link time when the
original char arrays are not in scope anymore. Enabling *synchronous*
debug output circumvents this bug. Can be triggered by running
TransformFeedbackGLTest with GL_KHR_debug extension disabled.
Hugo Amiard