To make room for two more 16-bit skinning-related values in the
PhongDrawUniform -- joint offset for multidraw and per-instance joint
count for instancing.
Originally I made those full 32 bits because I wanted to provide an
option to have a 64-bit light mask there instead of an offset + count.
But the mask is not really driver-friendly as going over the bits and
skipping zeros was behaving like if each pixel was affected by 64 lights
-- an absolute perf nightmare. I might reconsider this again later, but
for now that doesn't seem to make sense, and I need to put the
skinning-related info somewhere without inflating the per-draw uniform
by another 16-byte vector.
Note that the order is *reversed* compared to the originally reserved
attribute IDs. This is because the "joint <id> has <weight>" order
feels more natural and consistent than "<weight> is assigned to joint
<id>".
Co-authored-by: Vladimír Vondruš <mosra@centrum.cz>
Those were originally named set*Buffer(), but in the process of
finishing up ef9da0ec96 got changed to
bind*Buffer() to avoid a false impression that the buffer stays bound to
the shader instance forever (which it doesn't, same as with textures).
However the documentation didn't get updated, apparently.
A considerable chunk of the docs mentioned that there has to be one
ProjectionUniform3D per draw. Probably a copypaste error from the case
where there's a combined TrannsformationProjectionUniform3D, which *is*
one per draw. Sorry for the confusion.
There was also quite a lot of documentation content referencing the old
deprecated constructors. Fixed now.
What's especially nice is that the code snippets no longer need to
describe that there's "2 lights, 3 materials and 5 draws" because now
it's self-documenting.
Because it was no longer bearable with three UnsignedInt arguments in a
row, especially when some of them are only available on a subset of
platforms. And it would get even worse with introduction of planned
features such as multiview or skinning.
Backwards compatibility is in place, as always. To ensure nothing
breaks, this commit still has all tests and snippets using the old API.
This would be causing an ambiguity in the upcoming shader setup rework.
It's unlikely to be used in practice like this, so I don't think I
should be accounting for such ambiguity.
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.
The class is rather heavy (strings, STL vector) and it'll stay heavier
than strictly needed even after the planned STL cleanup -- shader users
should not bear the overhead of Array, StringView etc. that it needs in
order to compile the shader sources.
I might eventually come to a different conclusion (maybe separating
GL::Shader population and usage like doing in Vulkan with CreateInfos),
but right now this commit has the best available solution -- converting
the instance to a lightweight class containing just ID and type, and
then converting that back to a GL::Shader upon checking compilation/link
status.
While at it, also removed the not-strictly-needed Optional usage from
the header. It wouldn't work with forward-declared GL::Shader anyway.
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().
Similar to the change done in Corrade, see the commit for details:
878624ac36
Wow, this is probably the most backwards-compatibility code I've ever
written. Can't wait until I can drop all that.
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.
It limits the support for CMake 3.12+, but it's much less verbose and I
don't expect people to use ancient CMake versions with IDEs like Xcode
or VS anyway, so this should be fine.
Fails spectacularly -- the geometry shader is aware only of instanced
object ID, and of vertex ID not at all. The former was a corner case
TODO while I was adding non-instanced object ID visualization in
033e56ec23 and which I kinda forgot about,
the latter was discovered while trying to fix the former.
Fix in the next commit.
Vladimír Vondruš