A base class encapsulating a GPU sampler object.
The subclasses of HdStSamplerObject mirror the subclasses of HdStTextureObject with the intention that they will be used in conjunction (e.g., the not yet existing HdStPtexSamplerObject will have two samplers and texture sampler handles for the texels and layout texture in a HdStPtexTextureObject).
The GPU resources is con-/destructed immediately in the c'tor/d'tor. By going through the HdSt_SamplerObjectRegistry, we can obtain a shared pointer that can safely be dropped in a different thread. The HdSt_SamplerObjectRegistry is also dispatching by texture type to construct the corresponding sampler type.
Definition at line 65 of file samplerObject.h.