While 27f6cc309d made it easier to create
references to attribute-less meshes by avoiding a branch on
attributeCount() (and then using a constructor with explicit vertex
count), code still had to branch on isIndexed() because indices() could
be called only on indexed meshes. This change allows code like
Trade::MeshData reference{data.primitive(),
{}, data.indexData(), Trade::MeshIndexData{data.indices()},
{}, data.vertexData(), Trade::meshAttributeDataNonOwningArray(data.attributeData()),
data.vertexCount()};
which works correctly for all cases and doesn't introduce extra branches
and code paths that would need to be tested. While definitely better, I
might still give up at some point and introduce some
Trade::MeshData::nonOwningImmutableReference() helper for this.
Vladimír Vondruš
521a3dac0b