Vertex layout for the optional uv stream: one tightly packed vec2<f32>.
@location(2) rather than 1, even though uvs are read by a variant that
often carries no colours: a shader location is a name, and giving uv and
colour the same number would mean two different meanings for one location
across variants of one shader family — which is exactly the confusion the
eventual WGSL emitter (RFC 0001) must not have to disambiguate.
Vertex layout for the optional uv stream: one tightly packed
vec2<f32>.@location(2)rather than1, even though uvs are read by a variant that often carries no colours: a shader location is a name, and giving uv and colour the same number would mean two different meanings for one location across variants of one shader family — which is exactly the confusion the eventual WGSL emitter (RFC 0001) must not have to disambiguate.