reg_field: add field_relax device dispatch + bump cpu/cuda pins

cpu

@@ -0,0 +1 @@
+../fastfields-cpu-lib

cuda

@@ -0,0 +1 @@
+../fastfields-cuda-lib

reg_field.cpp

@@ -80,4 +80,29 @@ void field_kernel(
  throw std::invalid_argument("unsupported device");
 }
 
+void field_relax(
+ DLTensor & sol ,
+ const DLTensor & hes ,
+ const DLTensor & grd ,
+ const double * voxel_size,
+ const double * absolute ,
+ const double * membrane ,
+ const double * bending ,
+ int8_t bound ,
+ int ndim ,
+ int nb_iter ,
+ int stream )
+{
+#ifdef FF_WITH_CUDA
+ if (IS_CUDA(sol))
+ return FF_CUDA::field_relax(sol, hes, grd, voxel_size, absolute, membrane, bending, bound, ndim, nb_iter, stream);
+#endif
+ if (IS_CPU(sol))
+ return FF_CPU::field_relax(sol, hes, grd, voxel_size, absolute, membrane, bending, bound, ndim, nb_iter, stream);
+
+ if (IS_CUDA(sol))
+ throw std::invalid_argument("fastfields: built without CUDA support, cannot operate on CUDA tensors");
+ throw std::invalid_argument("unsupported device");
+}
+
 FF_NAMESPACE_END(FF)

reg_field.h

@@ -106,6 +106,34 @@ void field_kernel(
  int stream = 0
 );
 
+/**
+ * @brief In-place relaxation (Gauss-Seidel) sweeps solving `(H + L) x = g`.
+ *
+ * Refines the warm-started field `sol` towards the solution of the regularised
+ * system, where `H` is the per-voxel compact-symmetric Hessian (`hes`, packed
+ * `C*(C+1)/2` last axis), `L` the field regulariser (same per-channel penalties
+ * as `field_matvec`), and `g` the gradient (`grd`, `C` last axis). Runs
+ * `nb_iter` red-black sweeps and writes the refined solution back into `sol`.
+ *
+ * @param sol Field to refine, in/out (*batch, *spatial, C)
+ * @param hes Compact-symmetric Hessian (*batch, *spatial, C*(C+1)/2)
+ * @param grd Gradient (*batch, *spatial, C)
+ * @param nb_iter Number of relaxation iterations
+ */
+void field_relax(
+ DLTensor & sol ,
+ const DLTensor & hes ,
+ const DLTensor & grd ,
+ const double * voxel_size = nullptr,
+ const double * absolute = nullptr,
+ const double * membrane = nullptr,
+ const double * bending = nullptr,
+ int8_t bound = bound_t::DCT2,
+ int ndim = 1,
+ int nb_iter = 1,
+ int stream = 0
+);
+
 FF_NAMESPACE_END(FF)
 
 #endif // FF_LIB_REG_FIELD