Geoiterator for unstructured grids (Part 1)

definitions/grib2/templates/template.3.101.def

@@ -14,3 +14,6 @@ unsigned[1] numberOfGridInReference : dump;
 byte[16] uuidOfHGrid : dump;
 
 template_nofail unstructuredGrid "grib2/localConcepts/[centre:s]/unstructuredGrid.def";
+
+iterator unstructured(numberOfPoints, missingValue, values,
+          numberOfGridUsed, numberOfGridInReference, uuidOfHGrid);

src/CMakeLists.txt

@@ -332,6 +332,7 @@ list( APPEND eccodes_src_files
     grib_nearest_class_polar_stereographic.cc
     grib_nearest_class_space_view.cc
     grib_iterator_class_polar_stereographic.cc
+    grib_iterator_class_unstructured.cc
     grib_iterator_class_lambert_azimuthal_equal_area.cc
     grib_iterator_class_lambert_conformal.cc
     grib_iterator_class_mercator.cc

src/grib_iterator_class.h

@@ -11,3 +11,4 @@ extern grib_iterator_class* grib_iterator_class_mercator;
 extern grib_iterator_class* grib_iterator_class_polar_stereographic;
 extern grib_iterator_class* grib_iterator_class_regular;
 extern grib_iterator_class* grib_iterator_class_space_view;
+extern grib_iterator_class* grib_iterator_class_unstructured;

src/grib_iterator_class_unstructured.cc

@@ -0,0 +1,168 @@
+/*
+ * (C) Copyright 2005- ECMWF.
+ *
+ * This software is licensed under the terms of the Apache Licence Version 2.0
+ * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
+ * virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
+ */
+
+#include "grib_api_internal.h"
+#include <cmath>
+
+/*
+   This is used by make_class.pl
+
+   START_CLASS_DEF
+   CLASS      = iterator
+   SUPER      = grib_iterator_class_gen
+   IMPLEMENTS = destroy
+   IMPLEMENTS = init;next
+   MEMBERS     =   double *lats
+   MEMBERS     =   double *lons
+   MEMBERS     =   long Nj
+   END_CLASS_DEF
+*/
+
+/* START_CLASS_IMP */
+
+/*
+
+Don't edit anything between START_CLASS_IMP and END_CLASS_IMP
+Instead edit values between START_CLASS_DEF and END_CLASS_DEF
+or edit "iterator.class" and rerun ./make_class.pl
+
+*/
+
+
+static void init_class        (grib_iterator_class*);
+static int init               (grib_iterator* i,grib_handle*,grib_arguments*);
+static int next               (grib_iterator* i, double *lat, double *lon, double *val);
+static int destroy            (grib_iterator* i);
+
+
+typedef struct grib_iterator_unstructured{
+  grib_iterator it;
+    /* Members defined in gen */
+    int carg;
+    const char* missingValue;
+    /* Members defined in unstructured */
+    double *lats;
+    double *lons;
+    long Nj;
+} grib_iterator_unstructured;
+
+extern grib_iterator_class* grib_iterator_class_gen;
+
+static grib_iterator_class _grib_iterator_class_unstructured = {
+    &grib_iterator_class_gen,                    /* super                     */
+    "unstructured",                    /* name                      */
+    sizeof(grib_iterator_unstructured),/* size of instance          */
+    0,                           /* inited */
+    &init_class,                 /* init_class */
+    &init,                     /* constructor               */
+    &destroy,                  /* destructor                */
+    &next,                     /* Next Value                */
+    0,                 /*  Previous Value           */
+    0,                    /* Reset the counter         */
+    0,                 /* has next values           */
+};
+
+grib_iterator_class* grib_iterator_class_unstructured = &_grib_iterator_class_unstructured;
+
+
+static void init_class(grib_iterator_class* c)
+{
+    c->previous    =    (*(c->super))->previous;
+    c->reset    =    (*(c->super))->reset;
+    c->has_next    =    (*(c->super))->has_next;
+}
+/* END_CLASS_IMP */
+
+#define ITER "Unstructured grid Geoiterator"
+
+static int next(grib_iterator* iter, double* lat, double* lon, double* val)
+{
+    grib_iterator_unstructured* self = (grib_iterator_unstructured*)iter;
+
+    if ((long)iter->e >= (long)(iter->nv - 1))
+        return 0;
+    iter->e++;
+
+    *lat = self->lats[iter->e];
+    *lon = self->lons[iter->e];
+    if (val && iter->data) {
+        *val = iter->data[iter->e];
+    }
+    return 1;
+}
+
+static int init(grib_iterator* iter, grib_handle* h, grib_arguments* args)
+{
+    // int ret = 0;
+    // double *lats, *lons; /* arrays for latitudes and longitudes */
+//    grib_iterator_unstructured* self = (grib_iterator_unstructured*)iter;
+    return GRIB_NOT_IMPLEMENTED;
+
+    // const char* s_radius                 = grib_arguments_get_name(h, args, self->carg++);
+    // const char* s_nx                     = grib_arguments_get_name(h, args, self->carg++);
+    // const char* s_ny                     = grib_arguments_get_name(h, args, self->carg++);
+    // const char* s_latFirstInDegrees      = grib_arguments_get_name(h, args, self->carg++);
+    // const char* s_lonFirstInDegrees      = grib_arguments_get_name(h, args, self->carg++);
+    // const char* s_southPoleOnPlane       = grib_arguments_get_name(h, args, self->carg++);
+    // const char* s_centralLongitude       = grib_arguments_get_name(h, args, self->carg++);
+    // const char* s_centralLatitude        = grib_arguments_get_name(h, args, self->carg++);
+    // const char* s_Dx                     = grib_arguments_get_name(h, args, self->carg++);
+    // const char* s_Dy                     = grib_arguments_get_name(h, args, self->carg++);
+    // const char* s_iScansNegatively       = grib_arguments_get_name(h, args, self->carg++);
+    // const char* s_jScansPositively       = grib_arguments_get_name(h, args, self->carg++);
+    // const char* s_jPointsAreConsecutive  = grib_arguments_get_name(h, args, self->carg++);
+    // const char* s_alternativeRowScanning = grib_arguments_get_name(h, args, self->carg++);
+
+    // if (iter->nv != nx * ny) {
+    //     grib_context_log(h->context, GRIB_LOG_ERROR, "%s: Wrong number of points (%zu!=%ldx%ld)", ITER, iter->nv, nx, ny);
+    //     return GRIB_WRONG_GRID;
+    // }
+    // if ((ret = grib_get_double_internal(h, s_latFirstInDegrees, &latFirstInDegrees)) != GRIB_SUCCESS)
+    //     return ret;
+    // if ((ret = grib_get_double_internal(h, s_lonFirstInDegrees, &lonFirstInDegrees)) != GRIB_SUCCESS)
+    //     return ret;
+    // if ((ret = grib_get_long_internal(h, s_southPoleOnPlane, &southPoleOnPlane)) != GRIB_SUCCESS)
+    //     return ret;
+    // if ((ret = grib_get_double_internal(h, s_centralLongitude, &centralLongitudeInDegrees)) != GRIB_SUCCESS)
+    //     return ret;
+    // if ((ret = grib_get_double_internal(h, s_centralLatitude, &centralLatitudeInDegrees)) != GRIB_SUCCESS)
+    //     return ret;
+    // if ((ret = grib_get_double_internal(h, s_Dx, &Dx)) != GRIB_SUCCESS)
+    //     return ret;
+    // if ((ret = grib_get_double_internal(h, s_Dy, &Dy)) != GRIB_SUCCESS)
+    //     return ret;
+    // if ((ret = grib_get_long_internal(h, s_jPointsAreConsecutive, &jPointsAreConsecutive)) != GRIB_SUCCESS)
+    //     return ret;
+    // if ((ret = grib_get_long_internal(h, s_jScansPositively, &jScansPositively)) != GRIB_SUCCESS)
+    //     return ret;
+    // if ((ret = grib_get_long_internal(h, s_iScansNegatively, &iScansNegatively)) != GRIB_SUCCESS)
+    //     return ret;
+    // if ((ret = grib_get_long_internal(h, s_alternativeRowScanning, &alternativeRowScanning)) != GRIB_SUCCESS)
+    //     return ret;
+
+    // iter->e = -1;
+
+    // /* Apply the scanning mode flags which may require data array to be transformed */
+    // ret = transform_iterator_data(h->context, iter->data,
+    //                               iScansNegatively, jScansPositively, jPointsAreConsecutive, alternativeRowScanning,
+    //                               iter->nv, nx, ny);
+
+    // return ret;
+}
+
+static int destroy(grib_iterator* i)
+{
+    grib_iterator_unstructured* self = (grib_iterator_unstructured*)i;
+    const grib_context* c                   = i->h->context;
+
+    grib_context_free(c, self->lats);
+    grib_context_free(c, self->lons);
+    return GRIB_SUCCESS;
+}

src/grib_iterator_factory.h

@@ -11,3 +11,4 @@
 { "polar_stereographic", &grib_iterator_class_polar_stereographic, },
 { "regular", &grib_iterator_class_regular, },
 { "space_view", &grib_iterator_class_space_view, },
+{ "unstructured", &grib_iterator_class_unstructured, },