Whoops, work-around for #926 correctly.

[flightgear.git] / src / Navaids / navrecord.cxx

diff --git a/src/Navaids/navrecord.cxx b/src/Navaids/navrecord.cxx
index 0695010cdf60df96e30b9a8dface8928f290f63f..c73e04b8fcb6a93ea1be64e40a9b849e1833d195 100644 (file)
--- a/src/Navaids/navrecord.cxx
+++ b/src/Navaids/navrecord.cxx
@@ -27,105 +27,70 @@
 #include <istream>
 
 #include <simgear/misc/sgstream.hxx>
+#include <simgear/misc/sg_path.hxx>
 #include <simgear/structure/exception.hxx>
 #include <simgear/debug/logstream.hxx>
+#include <simgear/sg_inlines.h>
+#include <simgear/props/props.hxx>
+
 
 #include <Navaids/navrecord.hxx>
 #include <Navaids/navdb.hxx>
 #include <Airports/runways.hxx>
+#include <Airports/simple.hxx>
+#include <Airports/xmlloader.hxx>
 #include <Main/fg_props.hxx>
+#include <Navaids/NavDataCache.hxx>
 
-FGNavRecord::FGNavRecord(Type aTy, const std::string& aIdent, 
+FGNavRecord::FGNavRecord(PositionedID aGuid, Type aTy, const std::string& aIdent,
   const std::string& aName, const SGGeod& aPos,
-  int aFreq, int aRange, double aMultiuse) :
-  FGPositioned(aTy, aIdent, aPos),
+  int aFreq, int aRange, double aMultiuse, PositionedID aRunway) :
+  FGPositioned(aGuid, aTy, aIdent, aPos),
   freq(aFreq),
   range(aRange),
   multiuse(aMultiuse),
-  _name(aName),
-  serviceable(true),
-  trans_ident(aIdent)
+  mName(aName),
+  mRunway(aRunway),
+  serviceable(true)
 { 
-  initAirportRelation();
+}
 
-  // Ranges are included with the latest data format, no need to
-  // assign our own defaults, unless the range is not set for some
-  // reason.
-  if (range < 0.1) {
-    SG_LOG(SG_GENERAL, SG_WARN, "navaid " << ident() << " has no range set, using defaults");
-    switch (type()) {
-    case NDB:
-    case VOR:
-      range = FG_NAV_DEFAULT_RANGE;
-      break;
-    
-    case LOC:
-    case ILS:
-    case GS:
-      range = FG_LOC_DEFAULT_RANGE;
-      break;
-      
-    case DME:
-      range = FG_DME_DEFAULT_RANGE;
-      break;
-    
-    default:
-      range = FG_LOC_DEFAULT_RANGE;
-    }
-  }
-  
+FGRunway* FGNavRecord::runway() const
+{
+  return (FGRunway*) flightgear::NavDataCache::instance()->loadById(mRunway);
 }
 
-void FGNavRecord::initAirportRelation()
+double FGNavRecord::localizerWidth() const
 {
-  if ((type() < ILS) || (type() > GS)) {
-    return; // not airport-located
+  if (!mRunway) {
+    return 6.0;
   }
   
-  FGRunway* runway = getRunwayFromName(_name);    
-  // fudge elevation to the runway elevation if it's not specified
-  if (fabs(elevation()) < 0.01) {
-    mPosition.setElevationFt(runway->elevation());
-  }
+  FGRunway* rwy = runway();
+  SGVec3d thresholdCart(SGVec3d::fromGeod(rwy->threshold()));
+  double axisLength = dist(cart(), thresholdCart);
+  double landingLength = dist(thresholdCart, SGVec3d::fromGeod(rwy->end()));
   
-  // align localizers with their runway
-  if ((type() == ILS) || (type() == LOC)) {
-    if (!fgGetBool("/sim/navdb/localizers/auto-align", true)) {
-      return;
-    }
-    
-   double threshold 
-     = fgGetDouble( "/sim/navdb/localizers/auto-align-threshold-deg", 5.0 );
-    alignLocaliserWithRunway(runway, threshold);
+// Reference: http://dcaa.slv.dk:8000/icaodocs/
+// ICAO standard width at threshold is 210 m = 689 feet = approx 700 feet.
+// ICAO 3.1.1 half course = DDM = 0.0775
+// ICAO 3.1.3.7.1 Sensitivity 0.00145 DDM/m at threshold
+//  implies peg-to-peg of 214 m ... we will stick with 210.
+// ICAO 3.1.3.7.1 "Course sector angle shall not exceed 6 degrees."
+              
+// Very short runway:  less than 1200 m (4000 ft) landing length:
+  if (landingLength < 1200.0) {
+// ICAO fudges localizer sensitivity for very short runways.
+// This produces a non-monotonic sensitivity-versus length relation.
+    axisLength += 1050.0;
   }
-}
-
-void FGNavRecord::alignLocaliserWithRunway(FGRunway* aRunway, double aThreshold)
-{
-// find the distance from the threshold to the localizer
-  SGGeod runwayThreshold(aRunway->threshold());
-  double dist, az1, az2;
-  SGGeodesy::inverse(mPosition, runwayThreshold, az1, az2, dist);
 
-// back project that distance along the runway center line
-  SGGeod newPos = aRunway->pointOnCenterline(dist);
+// Example: very short: San Diego   KMYF (Montgomery Field) ILS RWY 28R
+// Example: short:      Tom's River KMJX (Robert J. Miller) ILS RWY 6
+// Example: very long:  Denver      KDEN (Denver)           ILS RWY 16R
+  double raw_width = 210.0 / axisLength * SGD_RADIANS_TO_DEGREES;
+  return raw_width < 6.0? raw_width : 6.0;
 
-  double hdg_diff = get_multiuse() - aRunway->headingDeg();
-
-  // clamp to [-180.0 ... 180.0]
-  if ( hdg_diff < -180.0 ) {
-      hdg_diff += 360.0;
-  } else if ( hdg_diff > 180.0 ) {
-      hdg_diff -= 360.0;
-  }
-
-  if ( fabs(hdg_diff) <= aThreshold ) {
-    mPosition = newPos;
-    set_multiuse( aRunway->headingDeg() );
-  } else {
-    SG_LOG(SG_GENERAL, SG_WARN, "localizer:" << ident() << ", aligning with runway " 
-      << aRunway->ident() << " exceeded heading threshold");
-  }
 }
 
 FGTACANRecord::FGTACANRecord(void) :