Refactoring and splint cleanup.

1 files changed, 7 insertions, 73 deletions

diff --git a/cgps.c b/cgps.c
index e60099ed..8a70a6d0 100644
--- a/cgps.c
+++ b/cgps.c
@@ -131,74 +131,6 @@ static bool compass_flag = false;
 #define GPS_ERROR	-2	/* low-level failure in GPS read */
 #define GPS_TIMEOUT	-3	/* low-level failure in GPS waiting */
 
-/* Convert true heading to magnetic.  Taken from the Aviation
-   Formulary v1.43.  Valid to within two degrees within the
-   continiental USA except for the following airports: MO49 MO86 MO50
-   3K6 02K and KOOA.  AK correct to better than one degree.  Western
-   Europe correct to within 0.2 deg.
-
-   If you're not in one of these areas, I apologize, I don't have the
-   math to compute your varation.  This is obviously extremely
-   floating-point heavy, so embedded people, beware of using.
-
-   Note that there are issues with using magnetic heading.  This code
-   does not account for the possibility of travelling into or out of
-   an area of valid calculation beyond forcing the magnetic conversion
-   off.  A better way to communicate this to the user is probably
-   desirable (in case the don't notice the subtle change from "(mag)"
-   to "(true)" on their display).
- */
-static float true2magnetic(double lat, double lon, double heading)
-{
-    /* Western Europe */
-    /*@ -evalorder +relaxtypes @*/
-    if ((lat > 36.0) && (lat < 68.0) && (lon > -10.0) && (lon < 28.0)) {
-	heading =
-	    (10.4768771667158 - (0.507385322418858 * lon) +
-	     (0.00753170031703826 * pow(lon, 2))
-	     - (1.40596203924748e-05 * pow(lon, 3)) -
-	     (0.535560699962353 * lat)
-	     + (0.0154348808069955 * lat * lon) -
-	     (8.07756425110592e-05 * lat * pow(lon, 2))
-	     + (0.00976887198864442 * pow(lat, 2)) -
-	     (0.000259163929798334 * lon * pow(lat, 2))
-	     - (3.69056939266123e-05 * pow(lat, 3)) + heading);
-    }
-    /* USA */
-    else if ((lat > 24.0) && (lat < 50.0) && (lon > 66.0) && (lon < 125.0)) {
-	lon = 0.0 - lon;
-	heading =
-	    ((-65.6811) + (0.99 * lat) + (0.0128899 * pow(lat, 2)) -
-	     (0.0000905928 * pow(lat, 3)) + (2.87622 * lon)
-	     - (0.0116268 * lat * lon) - (0.00000603925 * lon * pow(lat, 2)) -
-	     (0.0389806 * pow(lon, 2))
-	     - (0.0000403488 * lat * pow(lon, 2)) +
-	     (0.000168556 * pow(lon, 3)) + heading);
-    }
-    /* AK */
-    else if ((lat > 54.0) && (lon > 130.0) && (lon < 172.0)) {
-	lon = 0.0 - lon;
-	heading =
-	    (618.854 + (2.76049 * lat) - (0.556206 * pow(lat, 2)) +
-	     (0.00251582 * pow(lat, 3)) - (12.7974 * lon)
-	     + (0.408161 * lat * lon) + (0.000434097 * lon * pow(lat, 2)) -
-	     (0.00602173 * pow(lon, 2))
-	     - (0.00144712 * lat * pow(lon, 2)) +
-	     (0.000222521 * pow(lon, 3)) + heading);
-    } else {
-	/* We don't know how to compute magnetic heading for this
-	 * location. */
-	magnetic_flag = false;
-    }
-
-    /* No negative headings. */
-    if (heading < 0.0)
-	heading += 360.0;
-
-    return (heading);
-    /*@ +evalorder -relaxtypes @*/
-}
-
 /* Function to call when we're all done.  Does a bit of clean-up. */
 static void die(int sig)
 {
@@ -584,15 +516,17 @@ static void update_gps_panel(struct gps_data_t *gpsdata)
     (void)mvwprintw(datawin, 5, DATAWIN_VALUE_OFFSET, "%-*s", 27, scr);
 
     /* Fill in the heading. */
-    if (gpsdata->fix.mode >= MODE_2D && isnan(gpsdata->fix.track) == 0)
-	if (!magnetic_flag) {
+    if (gpsdata->fix.mode >= MODE_2D && isnan(gpsdata->fix.track) == 0) {
+	double magheading = true2magnetic(gpsdata->fix.latitude,
+					 gpsdata->fix.longitude,
+					  gpsdata->fix.track);
+	if (!magnetic_flag || isnan(magheading) != 0) {
 	    (void)snprintf(scr, sizeof(scr), "%.1f deg (true)",
 			   gpsdata->fix.track);
 	} else {
 	    (void)snprintf(scr, sizeof(scr), "%.1f deg (mag) ",
-			   true2magnetic(gpsdata->fix.latitude,
-					 gpsdata->fix.longitude,
-					 gpsdata->fix.track));
+		magheading);
+	}
     } else
 	(void)snprintf(scr, sizeof(scr), "n/a");
     (void)mvwprintw(datawin, 6, DATAWIN_VALUE_OFFSET, "%-*s", 27, scr);