From af0ad80b51fb1a95b89dc989dff0bb1580102072 Mon Sep 17 00:00:00 2001
From: mfranz <mfranz>
Date: Sat, 17 Jun 2006 16:33:00 +0000
Subject: [PATCH] move generation of lon/lat string representations here from
 cockpit.cxx. Thanks to tied functions, this is only executed when the node is
 read. This will be done by the old & new HUD code, the latter of which won't
 have a special lon/lat mode at all. Instead it will be regular labels that
 point to these properties for displaying lon/lat.    I would have liked to
 avoid the duplication of code (lon and lat being basically the same thing),
 and to avoid using static buffers and all, but ... if anyone wants to make it
 prettier, go ahead.    The format is controlled by /sim/lon-lat-format (will
 be changed if I find a better place).

---
 src/Main/fg_props.cxx | 71 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)

diff --git a/src/Main/fg_props.cxx b/src/Main/fg_props.cxx
index d027bf2fe..1ab498b29 100644
--- a/src/Main/fg_props.cxx
+++ b/src/Main/fg_props.cxx
@@ -433,6 +433,70 @@ setFDMDataLogging (bool state)
   }
 }
 
+static const char *
+getLongitudeString ()
+{
+  static SGConstPropertyNode_ptr n = fgGetNode("/position/longitude-deg", true);
+  static SGConstPropertyNode_ptr f = fgGetNode("/sim/lon-lat-format", true);
+  static char buf[32];
+  double d = n->getDoubleValue();
+  int format = f->getIntValue();
+
+  if (format == 0) {
+    snprintf(buf, 32, "%3.6f", d);
+
+  } else if (format == 1) {
+    // dd mm.mmm' (DMM-Format) -- uses a round-off factor tailored to the
+    // required precision of the minutes field (three decimal places),
+    // preventing minute values of 60.
+    double deg = fabs(d) + 5.0E-4 / 60.0;
+    double min = fabs(deg - int(deg)) * 60.0 - 4.999E-4;
+    snprintf(buf, 32, "%d*%06.3f%c", int(d < 0.0 ? -deg : deg), min,
+        d < 0.0 ? 'W' : 'E');
+
+  } else {
+    // mm'ss.s'' (DMS-Format) -- uses a round-off factor tailored to the
+    // required precision of the seconds field (one decimal place),
+    // preventing second values of 60.
+    double deg = fabs(d) + 0.05 / 3600.0;
+    double min = (deg - int(deg)) * 60.0;
+    double sec = (min - int(min)) * 60.0 - 0.049;
+    snprintf(buf, 32, "%d*%02d %04.1f%c", int(d < 0.0 ? -deg : deg),
+      int(min), sec, d < 0.0 ? 'W' : 'E');
+  }
+  return buf;
+}
+
+static const char *
+getLatitudeString ()
+{
+  static SGConstPropertyNode_ptr n = fgGetNode("/position/latitude-deg", true);
+  static SGConstPropertyNode_ptr f = fgGetNode("/sim/lon-lat-format", true);
+  static char buf[32];
+  double d = n->getDoubleValue();
+  int format = f->getIntValue();
+
+  if (format == 0) {
+    snprintf(buf, 32, "%3.6f", d);
+
+  } else if (format == 1) {
+    double deg = fabs(d) + 5.0E-4 / 60.0;
+    double min = fabs(deg - int(deg)) * 60.0 - 4.999E-4;
+    snprintf(buf, 32, "%d*%06.3f%c", int(d < 0.0 ? -deg : deg), min,
+        d < 0.0 ? 'S' : 'N');
+
+  } else {
+    double deg = fabs(d) + 0.05 / 3600.0;
+    double min = (deg - int(deg)) * 60.0;
+    double sec = (min - int(min)) * 60.0 - 0.049;
+    snprintf(buf, 32, "%d*%02d %04.1f%c", int(d < 0.0 ? -deg : deg),
+      int(min), sec, d < 0.0 ? 'S' : 'N');
+  }
+  return buf;
+}
+
+
+
 
 ////////////////////////////////////////////////////////////////////////
 // Tie the properties.
@@ -464,6 +528,10 @@ FGProperties::bind ()
   fgSetArchivable("/sim/time/gmt");
   fgTie("/sim/time/gmt-string", getGMTString);
 
+				// Position
+  fgTie("/position/latitude-string", getLatitudeString);
+  fgTie("/position/longitude-string", getLongitudeString);
+
 				// Orientation
   fgTie("/orientation/heading-magnetic-deg", getHeadingMag);
 
@@ -490,6 +558,9 @@ FGProperties::unbind ()
   fgUntie("/sim/time/elapsed-sec");
   fgUntie("/sim/time/gmt");
   fgUntie("/sim/time/gmt-string");
+				// Position
+  fgUntie("/position/latitude-string");
+  fgUntie("/position/longitude-string");
 
 				// Orientation
   fgUntie("/orientation/heading-magnetic-deg");