It was a clever harmless trick. Well, it was way more harmless than it
was clever, but even then it caused UBSan to complain. And that's Not A
Good Thing for various reasons, so let's just comply.
The main bad effect of this change is a *slightly* larger list of
exported symbols but until we actually get rid of the major bloats like
<iostream>, <string> and the like, this is not going to have any
measurable impact.
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.
Apmong other things where it's useful for end users as a more convenient
alternative to recreating the MeshData by hand, I need to use this
inside the transform() utilities to preserve all index buffer properties
without copypasting nasty code everywhere.
The type is now extended to 32 bits. In the GL and Vk libraries it means
one can now do things like
MeshIndexType type = meshIndexTypeWrap(GL_UNSIGNED_BYTE);
and passing that to GL::Mesh or Vk::Mesh will cause it to use the value
directly, instead of doing a mapping from a generic type. The *real* use
case for this is however to allow custom index buffer representations in
Trade::MeshData. Support for that will be hooked up in the following
commit.
Also not something the classic GPU vertex pipeline can handle, but
useful for other scenarios. Subsequently a support for array indices
will be added, allowing to directly represent for example OBJ files,
where each attribute has its own index buffer.
This is not something the classic GPU vertex pipeline can handle
(except maybe Vulkan, which can handle zero strides for instanced
attributes?), but useful for other scenarios. This means existing code
needs to be aware of and handle the new corner case.
Since the main speed advantage of the function is that it hashes a
*whole* vertex together instead of going through the attribute arrays
one by one, it can't really operate on whatever funny interleaved layout
it was given as there may be padding bytes with random content, breaking
the deduplication.
Since checking that a layout is really padding-less is rather complex,
the repacking is now performed always. This also means the && overload
makes no sense anymore and thus it was dropped.
This makes the test added in the previous commit not assert anymore, and
behave the same as the padding-less case.
This took me quite a while to realize -- not always it's desirable to
have the original layout unconditionally preserved, especially if for
example filtering a MeshData to just a subset of attributes.
Funny how even doing the *insanely complex* operation of extending a
MeshData with one extra attribute is still shorter than manually
populating the GL::Mesh.
Was browsing the extension registry looking for something else and found
this instead. It used to be ES catching up with desktop, now it's the
other way around.
Highly experimental and very assert-y, as it doesn't handle mesh
primitive / attribute type incompatibility or conversion of
loops/strips/fans to indexed meshes yet.
And doing all the automagic of unpacking packed types, converting
positions *and* normals/tangents/bitangents, and also an overload for
transforming texture coordinates.
Such a simple thing and yet so complex and nasty to test.
Probably a leftover from when these dependencies were handled in a
much shittier way? For as long as I remember, enabling WITH_GL_INFO
always enabled WITH_GL and WITH_WINDOWLESSWHATEVERAPPLICATION
implicitly.
Now it's a field and its corresponding object mapping, instead of
field and "objects":
- Goes better with the concept that there's not really any materialized
"object" anywhere, just fields mapped to them.
- No more weird singular/plural difference between field() and
objects(), it's field() and mapping() now.
- The objectCount() that actually wasn't really object count is now a
mappingBound(), an upper bound for object IDs contained in the object
mapping views. Which is quite self-explanatory without having to
mention every time that the range may be sparse.
Same as with MeshData2D/3D, the original ObjectData API and plugin
interfaces are preserved to keep existing code as well as existing
importer implementations working. As Magnum's own importers will get
updated to the new SceneData workflow, a backward compatibility layer
provided that translates it to the subset that the legacy ObjectData
understands.
With this commit, both existing plugin code can build (and test against)
the new workflow, and any ports to the new workflow can test against the
legacy interfaces. Except that for now the compatibility layer doesn't
deal with objects that have more than one mesh or for example a light
and a camera attached, this will be done in a separate step.
Vladimír Vondruš