Add support for acquiring OpenStreetMap Notes as GPX files.

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

diff --git a/src/coords.c b/src/coords.c
index df2391bc31813ccb14d1f13e4d8d19024e23cdfd..62a2d9f90d5885e5fd7de06d48704a43eae09c75 100644 (file)
--- a/src/coords.c
+++ b/src/coords.c
@@ -6,6 +6,8 @@ I (Evan Battaglia <viking@greentorch.org>) have only made some small changes suc
 renaming functions and defining LatLon and UTM structs.
 2004-02-10 -- I also added a function of my own -- a_coords_utm_diff() -- that I felt belonged in coords.c
 2004-02-21 -- I also added a_coords_utm_equal().
+2005-11-23 -- Added a_coords_dtostr() for lack of a better place.
+
 */
 /* coords.h - include file for coords routines
 **
@@ -33,16 +35,38 @@ renaming functions and defining LatLon and UTM structs.
 ** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 ** SUCH DAMAGE.
 */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
 
+#ifdef HAVE_STDLIB_H
 #include <stdlib.h>
+#endif
+#ifdef HAVE_STRING_H
 #include <string.h>
+#endif
+#ifdef HAVE_MATH_H
 #include <math.h>
+#endif
 
 #include "viking.h"
+#include "globals.h"
+#include "degrees_converters.h"
 
-#ifdef WINDOWS
-#define M_PI 3.14159265358979
-#endif
+/**
+ * Convert a double to a string WITHOUT LOCALE.
+ *
+ * Following GPX specifications, decimal values are xsd:decimal
+ * So, they must use the period separator, not the localized one.
+ *
+ * The returned value must be freed by g_free.
+ */
+char *a_coords_dtostr ( double d )
+{
+  gchar *buffer = g_malloc(G_ASCII_DTOSTR_BUF_SIZE*sizeof(gchar));
+  g_ascii_dtostr (buffer, G_ASCII_DTOSTR_BUF_SIZE, (gdouble) d);
+  return buffer;
+}
 
 #define PIOVER180 0.01745329252
 
@@ -74,11 +98,14 @@ double a_coords_utm_diff( const struct UTM *utm1, const struct UTM *utm2 )
 double a_coords_latlon_diff ( const struct LatLon *ll1, const struct LatLon *ll2 )
 {
   static struct LatLon tmp1, tmp2;
+  gdouble tmp3;
   tmp1.lat = ll1->lat * PIOVER180;
   tmp1.lon = ll1->lon * PIOVER180;
   tmp2.lat = ll2->lat * PIOVER180;
   tmp2.lon = ll2->lon * PIOVER180;
-  return EquatorialRadius * acos(sin(tmp1.lat)*sin(tmp2.lat)+cos(tmp1.lat)*cos(tmp2.lat)*cos(tmp1.lon-tmp2.lon));
+  tmp3 = EquatorialRadius * acos(sin(tmp1.lat)*sin(tmp2.lat)+cos(tmp1.lat)*cos(tmp2.lat)*cos(tmp1.lon-tmp2.lon));
+  // For very small differences we can sometimes get NaN returned
+  return isnan(tmp3)?0:tmp3;
 }
 
 void a_coords_latlon_to_utm( const struct LatLon *latlon, struct UTM *utm )
@@ -102,8 +129,8 @@ void a_coords_latlon_to_utm( const struct LatLon *latlon, struct UTM *utm )
        longitude -= 360.0;
 
     /* Now convert. */
-    lat_rad = latitude * M_PI / 180.0;
-    long_rad = longitude * M_PI / 180.0;
+    lat_rad = DEG2RAD(latitude);
+    long_rad = DEG2RAD(longitude);
     zone = (int) ( ( longitude + 180 ) / 6 ) + 1;
     if ( latitude >= 56.0 && latitude < 64.0 &&
         longitude >= 3.0 && longitude < 12.0 )
@@ -117,7 +144,7 @@ void a_coords_latlon_to_utm( const struct LatLon *latlon, struct UTM *utm )
        else if ( longitude >= 33.0 && longitude < 42.0 ) zone = 37;
        }
     long_origin = ( zone - 1 ) * 6 - 180 + 3;  /* +3 puts origin in middle of zone */
-    long_origin_rad = long_origin * M_PI / 180.0;
+    long_origin_rad = DEG2RAD(long_origin);
     eccPrimeSquared = EccentricitySquared / ( 1.0 - EccentricitySquared );
     N = EquatorialRadius / sqrt( 1.0 - EccentricitySquared * sin( lat_rad ) * sin( lat_rad ) );
     T = tan( lat_rad ) * tan( lat_rad );
@@ -212,9 +239,9 @@ void a_coords_utm_to_latlon( const struct UTM *utm, struct LatLon *latlon )
     R1 = EquatorialRadius * ( 1.0 - EccentricitySquared ) / pow( 1.0 - EccentricitySquared * sin( phi1_rad ) * sin( phi1_rad ), 1.5 );
     D = x / ( N1 * K0 );
     latitude = phi1_rad - ( N1 * tan( phi1_rad ) / R1 ) * ( D * D / 2 -( 5 + 3 * T1 + 10 * C1 - 4 * C1 * C1 - 9 * eccPrimeSquared ) * D * D * D * D / 24 + ( 61 + 90 * T1 + 298 * C1 + 45 * T1 * T1 - 252 * eccPrimeSquared - 3 * C1 * C1 ) * D * D * D * D * D * D / 720 );
-    latitude = latitude * 180.0 / M_PI;
+    latitude = RAD2DEG(latitude);
     longitude = ( D - ( 1 + 2 * T1 + C1 ) * D * D * D / 6 + ( 5 - 2 * C1 + 28 * T1 - 3 * C1 * C1 + 8 * eccPrimeSquared + 24 * T1 * T1 ) * D * D * D * D * D / 120 ) / cos( phi1_rad );
-    longitude = long_origin + longitude * 180.0 / M_PI;
+    longitude = long_origin + RAD2DEG(longitude);
 
     /* Show results. */
 
@@ -222,3 +249,29 @@ void a_coords_utm_to_latlon( const struct UTM *utm, struct LatLon *latlon )
     latlon->lon = longitude;
 
     }
+
+void a_coords_latlon_to_string ( const struct LatLon *latlon,
+                                gchar **lat,
+                                gchar **lon )
+{
+  g_return_if_fail ( latlon != NULL );
+
+  vik_degree_format_t format = a_vik_get_degree_format ();
+
+  switch (format) {
+  case VIK_DEGREE_FORMAT_DDD:
+    *lat = convert_lat_dec_to_ddd ( latlon->lat );
+    *lon = convert_lon_dec_to_ddd ( latlon->lon );
+    break;
+  case VIK_DEGREE_FORMAT_DMM:
+    *lat = convert_lat_dec_to_dmm ( latlon->lat );
+    *lon = convert_lon_dec_to_dmm ( latlon->lon );
+    break;
+  case VIK_DEGREE_FORMAT_DMS:
+    *lat = convert_lat_dec_to_dms ( latlon->lat );
+    *lon = convert_lon_dec_to_dms ( latlon->lon );
+    break;
+  default:
+    g_critical("Houston, we've had a problem. format=%d", format);
+  }
+}