Which is consistent with about everything else. No idea why I picked
such a strange API name.
Backwards compatibility aliases in place, as these are likely used by a
lot of code already. To ensure I didn't break anything, I'm updating all
code to use the new API in the next commit.
They were documented in the convenience accessor classes, but here it
makes sense too. The only attribute for which I'm hesitating to specify
a default is Phong shininess -- the value of 80 feels a bit too
arbitrary to be useful.
For cases where the whole MaterialAttributeData instance is needed and
calculating the right offset into the array returned by attributeData()
would be too error-prone.
Similar accessor is in MeshData already, so this achieves better feature
parity between the two.
Because storing arbitrary data as a string was not good:
- It *never* followed alignment requirements due to the last byte being
used for size. Instead the size is now stored before the data, and
thus the data is always on the 64 byte boundary.
- As it could contain arbitrary binary data, it could cause
magnum-sceneconverter --material-info to print garbage, corrupt the
terminal or, worst case, crash. Not good.
- It stored an implicit \0, which was unnecessary.
The enum-to-string conversion was just a private API and we need to use
it in various material filtering code. It was also a private class member
for some reason, even though it has no relation to / dependency on the
MaterialData class. So it's made a free function instead.
The MeshData and SceneData find APIs had the complexity documented, do
the same for MaterialData too. Plus cross-link this API from
hasAttribute() / hasField() so it's easier to find.
Logic mostly the same as with MaterialAttribute::*TextureCoordinates --
attribute not present is treated the same way as if the layer was 0
(since that's what a 2D non-array texture is, a single-slice array), and
conversely if the attribute is 0 it's the same as if it would be not
present at all. Plus it also gets checked in queries for packed
textures, if everything is the same but the layer is different, then
it's not a packed texture.
The rest of the commit is just busywork for convenience APIs.
Reason is that Assimp custom material attribute names are also prefixed
with $ and other weird characters, which could lead to them appearing
before $LayerName, causing a layer to falsely appear unnamed. A space,
instead, is before all printable characters so it's guaranteed to be
always first.
Some things you just don't realize at first. Fortunately the binary
layout isn't pinned yet for the serialization format so this change is
mostly fine.
Hah, so many overloads. Not providing mutable access to keys or layer
offsets as that would break the invariant of the internal array always
being sorted.
There's actually a lot of code involved in checking if all textures use
the same transform or coordinate set, especially when considering all
fallback variants and potential future expansion with separate texture
offset/scale/rotation attributes.
A lot of the complexity was thus hidden in plugin implementations, which
were each trying to find a common value for all textures to save the
user from doing the same. All that code can now be removed and left up
to the material APIs themselves -- now it's just about checking
hasCommonTextureTransformation() and then retrieving that one common
transformation, independently on how the material actually defines it.
Turns out glTF doesn't actually put metalness into R and roughness into
G, even though the naming suggests that. This was done originally, but
then they changed that in order to be compatible with UE4 and allow for
a more efficient storage of an occlusion map.
Because this feels extremely arbitrary, the docs have added rationale
for each of the packing variants, and I'm also renaming the packed
attribute and checks to imply the red channel isn't used.
This is a bit huge because of all the new overloads that take a
MaterialLayer instead of a string, but all that is just boring
boilerplate. Additionally this:
* exposes glTF clear coat parameters (which, interestingly enough,
reuse existing attributes and don't introduce any new)
* provides a convenience wrapper in PbrClearCoatMaterialData
* and a convenience base for material layer wrappers that redirect
all APIs with implicit layer argument to desired layer instead of the
base material
Well, "basic". Practically mirrors glTF PBR materials:
- builtin metallic/roughness
- the KHR_materials_pbrSpecularGlossiness extension
- extra normal/occlusion/emission maps
- exposes the implicit metallic/roughness and specular/glossiness
packing, but also allows separate maps with arbitrary packings as
well as two-channel normal maps (instead of three-channel)
- provides convenience checks for the most common packing schemes
including MSFT_packing_normalRoughnessMetallic and the three variants
of MSFT_packing_occlusionRoughnessMetallic
- teaches PhongMaterialData to recognize packed specular/glossiness
maps as well
Next up is exposing at least one layer extension, and then I'm done
here.