Merge commit 'viking-0.9.93' into help

[andy/viking.git] / src / dems.c

diff --git a/src/dems.c b/src/dems.c
index d3d889460cd504e5ef5204c5349b221c1855ea86..5052411536c1024fead3bb25ade1ede49980356a 100644 (file)
--- a/src/dems.c
+++ b/src/dems.c
@@ -158,3 +158,60 @@ gint16 a_dems_list_get_elev_by_coord ( GList *dems, const VikCoord *coord )
   }
   return VIK_DEM_INVALID_ELEVATION;
 }
+
+typedef struct {
+  const VikCoord *coord;
+  VikDemInterpol method;
+  gint elev;
+} CoordElev;
+
+static gboolean get_elev_by_coord(gpointer key, LoadedDEM *ldem, CoordElev *ce)
+{
+  VikDEM *dem = ldem->dem;
+  gdouble lat, lon;
+
+  if ( dem->horiz_units == VIK_DEM_HORIZ_LL_ARCSECONDS ) {
+    struct LatLon ll_tmp;
+    vik_coord_to_latlon (ce->coord, &ll_tmp );
+    lat = ll_tmp.lat * 3600;
+    lon = ll_tmp.lon * 3600;
+  } else if (dem->horiz_units == VIK_DEM_HORIZ_UTM_METERS) {
+    static struct UTM utm_tmp;
+    if (utm_tmp.zone != dem->utm_zone)
+      return FALSE;
+    vik_coord_to_utm (ce->coord, &utm_tmp);
+    lat = utm_tmp.northing;
+    lon = utm_tmp.easting;
+  } else
+    return FALSE;
+
+  switch (ce->method) {
+    case VIK_DEM_INTERPOL_NONE:
+      ce->elev = vik_dem_get_east_north(dem, lon, lat);
+      break;
+    case VIK_DEM_INTERPOL_SIMPLE:
+      ce->elev = vik_dem_get_simple_interpol(dem, lon, lat);
+      break;
+    case VIK_DEM_INTERPOL_BEST:
+      ce->elev = vik_dem_get_shepard_interpol(dem, lon, lat);
+      break;
+  }
+  return (ce->elev != VIK_DEM_INVALID_ELEVATION);
+}
+
+/* TODO: keep a (sorted) linked list of DEMs and select the best resolution one */
+gint16 a_dems_get_elev_by_coord ( const VikCoord *coord, VikDemInterpol method )
+{
+  CoordElev ce;
+
+  if (!loaded_dems)
+    return VIK_DEM_INVALID_ELEVATION;
+
+  ce.coord = coord;
+  ce.method = method;
+  ce.elev = VIK_DEM_INVALID_ELEVATION;
+
+  if(!g_hash_table_find(loaded_dems, (GHRFunc)get_elev_by_coord, &ce))
+    return VIK_DEM_INVALID_ELEVATION;
+  return ce.elev;
+}