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.
Hah this took a while, as there was no texture scaffolding in place at
all. Thus all this had to be added and tested for the first time:
* 2D textures
* 2D texture arrays
* Texture transformation uniforms
* Texture transformation UBOs
* Instanced texture offset
This also means that MeshVisualizer can be used to visualize arbitrary
(single-channel) integer textures now, not just render meshes with
object ID textures. Yay for feature parity!
Mainly to have feature parity with Flat and Phong -- otherwise switching
to draw a wireframe on an instanced mesh would be too annoying. Also, if
we have multidraw there already, why not instancing as well.
Originally the uniform wasn't present with the assumption that users
could easily adjust color map offset to achieve the same effect. That
was however unnecessarily annoying and error-prone in cases where it's
essential to have the same object IDs from multiple draws have a
matching color, and it was complicating multidraw workflows as the color
map offset was not a part of per-draw data, but rather material data.
The proper practice is to have GLES and WebGL requiurements separated,
as the two editions diverge more and more and treating one as a subset
of another no longer works.
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.
This is always true in the single-draw case, since setDrawOffset()
asserts on this. In the multi-draw case this optimization doesn't make
sense, because it doesn't make sense to create a multidraw shader with
just one draw.
On an Intel 630 GPU this resulted in single-draw single-material Phong
to go from 550 ms to 440, which is roughly a 20% improvement. For the
simpler shaders the difference is even higher. The multidraw numbers
stayed the same as before, obviously.
* Shader compilation failed with vertex, object and primitive ID
enabled due to the NO_GEOMETRY_SHADER define not being correctly
propagated
* Enabling just vertex ID visualization on WebGL caused an assert in
constructor, complaining that "at least one visualization feature has
to be enabled", which is wrong
* Defaults were not correctly set up for vertex ID rendering, causing
all-black render when setColor() wasn't called
* Forgot to list/bundle some ground truth test images for the test
case, causing the test to fail due to files not found
* The test asserted when generating mesh data due to an unhandled
corner case
* The test expected an ES2 assertion message on WebGL 2
* Flag::Wireframe now implicitly enables Flag::NoGeometryShader also on
WebGL. This was done only for ES2 previously, but WebGL doesn't have
(and won't have) geometry shaders, so it makes sense to do the same
there.
It was rendering everything with a plain color, which is rather useless.
Moreover it wasn't consistent with TBN visualization where you might
actually want only the lines rendered and not the triangle.
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.
Vladimír Vondruš