RemapGrid: add healpix members.

src/remap.h

@@ -14,6 +14,7 @@
 #include "remap_vars.h"
 #include "remap_grid_cell_search.h"
 #include "grid_point_search.h"
+#include "mpim_grid/grid_healpix.h"
 
 #ifndef M_PI
 #define M_PI 3.14159265358979323846264338327950288
@@ -62,13 +63,16 @@ struct  // RemapGrid
 RemapGrid
 // clang-format on
 {
+  RemapGridType type = RemapGridType::Undefined;
   int gridID = -1;
   int tmpgridID = -1;
-  RemapGridType type = RemapGridType::Undefined;
   int rank = 0;                 // rank of the grid
   size_t size = 0;              // total points on the grid
   size_t num_cell_corners = 0;  // number of corners for each grid cell
 
+  int nside = 0;
+  HpOrder order = HpOrder::Undef;
+
   bool needCellCorners = false;
   bool useCellCorners = false;  // use corners for bounding boxes