WIP - Add support for fully assembling operators with multiple active fields and different bases

Author: zatkins-dev

include/ceed-impl.h

@@ -359,6 +359,7 @@ struct CeedOperator_private {
   int (*LinearAssembleSymbolic)(CeedOperator, CeedSize *, CeedInt **, CeedInt **);
   int (*LinearAssemble)(CeedOperator, CeedVector);
   int (*LinearAssembleSingle)(CeedOperator, CeedInt, CeedVector);
+  int (*LinearAssembleSingleBlock)(CeedOperator, CeedInt, CeedInt, CeedInt, CeedVector);
   int (*CreateFDMElementInverse)(CeedOperator, CeedOperator *, CeedRequest *);
   int (*Apply)(CeedOperator, CeedVector, CeedVector, CeedRequest *);
   int (*ApplyComposite)(CeedOperator, CeedVector, CeedVector, CeedRequest *);

include/ceed/backend.h

@@ -474,7 +474,7 @@ CEED_EXTERN int CeedOperatorGetFallbackParent(CeedOperator op, CeedOperator *par
 CEED_EXTERN int CeedOperatorGetFallbackParentCeed(CeedOperator op, Ceed *parent);
 CEED_EXTERN int CeedOperatorLinearAssembleQFunctionBuildOrUpdateFallback(CeedOperator op, CeedVector *assembled, CeedElemRestriction *rstr,
                                                                          CeedRequest *request);
-CEED_INTERN int CeedOperatorAssembleSingle(CeedOperator op, CeedInt offset, CeedVector values);
+CEED_INTERN int CeedOperatorAssembleSingle(CeedOperator op, CeedSize offset, CeedVector values);
 CEED_EXTERN int CeedOperatorSetSetupDone(CeedOperator op);
 
 CEED_INTERN int CeedMatrixMatrixMultiply(Ceed ceed, const CeedScalar *mat_A, const CeedScalar *mat_B, CeedScalar *mat_C, CeedInt m, CeedInt n,