gridToCurvilinear: added support for CDI_PROJ_RLL.

src/grid.c

@@ -873,10 +873,19 @@ int gridToCurvilinear(int gridID1, int lbounds)
 {
   long index;
   int gridtype = gridInqType(gridID1);
+
   size_t gridsize = (size_t) gridInqSize(gridID1);
-  int gridID2  = gridCreate(GRID_CURVILINEAR, (int) gridsize);
+  int gridID2 = gridCreate(GRID_CURVILINEAR, (int) gridsize);
+
+  bool lrotated = false;
+  if ( gridtype == GRID_PROJECTION && gridInqProjType(gridID1) == CDI_PROJ_RLL )
+    {
+      gridtype = GRID_LONLAT;
+      lrotated = true;
+    }
+
   gridDefPrec(gridID2, DATATYPE_FLT32);
-	  
+
   switch (gridtype)
     {
     case GRID_LONLAT:
@@ -957,12 +966,22 @@ int gridToCurvilinear(int gridID1, int lbounds)
             else
               for ( int i = 0; i < ny; ++i ) yvals[i] = 0;
             
-	    if ( gridIsRotated(gridID1) )
-	      {		
-		double xpole = gridInqXpole(gridID1);
-		double ypole = gridInqYpole(gridID1);
-		double angle = gridInqAngle(gridID1);
-		
+	    if ( gridIsRotated(gridID1) || lrotated )
+	      {
+                double xpole = 0, ypole = 0, angle = 0;
+
+                if ( lrotated )
+                  {
+                    gridInqProjParamRLL(gridID1, &xpole, &ypole, &angle);
+                    gridDefProj(gridID2, gridID1);
+                  }
+                else
+                  {
+                    xpole = gridInqXpole(gridID1);
+                    ypole = gridInqYpole(gridID1);
+                    angle = gridInqAngle(gridID1);
+                  }
+
 		for ( int j = 0; j < ny; j++ )
 		  for ( int i = 0; i < nx; i++ )
 		    {