From a727e6958576e6bf6c2c3f632cbfc5f9415783c3 Mon Sep 17 00:00:00 2001
From: ehofman <ehofman>
Date: Mon, 8 Sep 2008 17:50:06 +0000
Subject: [PATCH] James Turner: Here's the very first FGPositioned patch -
 adding the files, and building them, but nothing else.

---
 src/Navaids/Makefile.am    |   3 +-
 src/Navaids/positioned.cxx | 438 +++++++++++++++++++++++++++++++++++++
 src/Navaids/positioned.hxx | 142 ++++++++++++
 3 files changed, 582 insertions(+), 1 deletion(-)
 create mode 100644 src/Navaids/positioned.cxx
 create mode 100644 src/Navaids/positioned.hxx

diff --git a/src/Navaids/Makefile.am b/src/Navaids/Makefile.am
index cff153f9b..a6201ae7f 100644
--- a/src/Navaids/Makefile.am
+++ b/src/Navaids/Makefile.am
@@ -7,7 +7,8 @@ libNavaids_a_SOURCES = \
 	fix.hxx fixlist.hxx fixlist.cxx \
 	awynet.hxx awynet.cxx \
 	navrecord.hxx navrecord.cxx \
-	navlist.hxx navlist.cxx
+	navlist.hxx navlist.cxx \
+	positioned.hxx positioned.cxx
 
 #	ils.hxx ilslist.hxx ilslist.cxx \
 #	mkrbeacons.hxx mkrbeacons.cxx 
diff --git a/src/Navaids/positioned.cxx b/src/Navaids/positioned.cxx
new file mode 100644
index 000000000..2d2309fed
--- /dev/null
+++ b/src/Navaids/positioned.cxx
@@ -0,0 +1,438 @@
+// positioned.cxx - base class for objects which are positioned 
+//
+// Copyright (C) 2008 James Turner
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+//
+// $Id$
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include <map>
+#include <set>
+
+#include <simgear/math/sg_geodesy.hxx>
+
+#include "positioned.hxx"
+
+typedef std::multimap<std::string, FGPositioned*> NamedPositionedIndex;
+typedef std::pair<NamedPositionedIndex::const_iterator, NamedPositionedIndex::const_iterator> NamedIndexRange;
+
+/**
+ * Order positioned elements by type, then pointer address. This allows us to
+ * use range searches (lower_ and upper_bound) to grab items of a particular
+ * type out of bucket efficently.
+ */
+class OrderByType
+{
+public:
+  bool operator()(const FGPositioned* a, const FGPositioned* b) const
+  {
+    if (a->type() == b->type()) return a < b;
+    return a->type() < b->type();
+  }
+};
+
+typedef std::set<FGPositioned*, OrderByType> BucketEntry;
+typedef std::map<long int, BucketEntry> SpatialPositionedIndex;
+
+static NamedPositionedIndex global_namedIndex;
+static SpatialPositionedIndex global_spatialIndex;
+
+SpatialPositionedIndex::iterator
+bucketEntryForPositioned(FGPositioned* aPos)
+{
+  int bucketIndex = aPos->bucket().gen_index();
+  SpatialPositionedIndex::iterator it = global_spatialIndex.find(bucketIndex);
+  if (it != global_spatialIndex.end()) {
+    return it;
+  }
+  
+  // create a new BucketEntry
+  return global_spatialIndex.insert(it, std::make_pair(bucketIndex, BucketEntry()));
+}
+
+static void
+addToIndices(FGPositioned* aPos)
+{
+  assert(aPos);
+  global_namedIndex.insert(global_namedIndex.begin(), 
+    std::make_pair(aPos->ident(), aPos));
+    
+  SpatialPositionedIndex::iterator it = bucketEntryForPositioned(aPos);
+  it->second.insert(aPos);
+}
+
+static void
+removeFromIndices(FGPositioned* aPos)
+{
+  assert(aPos);
+  
+  NamedPositionedIndex::iterator it = global_namedIndex.find(aPos->ident());
+  while (it != global_namedIndex.end() && (it->first == aPos->ident())) {
+    if (it->second == aPos) {
+      global_namedIndex.erase(it);
+      break;
+    }
+    
+    ++it;
+  }
+  
+  SpatialPositionedIndex::iterator sit = bucketEntryForPositioned(aPos);
+  sit->second.erase(aPos);
+}
+
+static void
+spatialFilterInBucket(const SGBucket& aBucket, const FGPositioned::Filter& aFilter, FGPositioned::List& aResult)
+{
+  SpatialPositionedIndex::const_iterator it;
+  it = global_spatialIndex.find(aBucket.gen_index());
+  if (it == global_spatialIndex.end()) {
+    return;
+  }
+  
+  BucketEntry::const_iterator l = it->second.begin();
+  BucketEntry::const_iterator u = it->second.end();
+
+  for ( ; l != u; ++l) {
+    if (aFilter(*l)) {
+      aResult.push_back(*l);
+    }
+  }
+}
+
+static void
+spatialFind(const SGGeod& aPos, double aRange, 
+  const FGPositioned::Filter& aFilter, FGPositioned::List& aResult)
+{
+  SGBucket buck(aPos);
+  double lat = aPos.getLatitudeDeg(),
+    lon = aPos.getLongitudeDeg();
+  
+  int bx = (int)( aRange*SG_NM_TO_METER / buck.get_width_m() / 2);
+  int by = (int)( aRange*SG_NM_TO_METER / buck.get_height_m() / 2 );
+    
+  // loop over bucket range 
+  for ( int i=-bx; i<=bx; i++) {
+    for ( int j=-by; j<=by; j++) {
+      spatialFilterInBucket(sgBucketOffset(lon, lat, i, j), aFilter, aResult);
+    } // of j-iteration
+  } // of i-iteration  
+}
+
+class LowerLimitOfType
+{
+public:
+  bool operator()(const FGPositioned* a, const FGPositioned::Type b) const
+  {
+    return a->type() < b;
+  }
+  
+  bool operator()(const FGPositioned::Type a, const FGPositioned* b) const
+  {
+    return a < b->type();
+  }
+};
+
+static void
+spatialFindTyped(const SGGeod& aPos, double aRange, FGPositioned::Type aLower, FGPositioned::Type aUpper, FGPositioned::List& aResult)
+{
+  SGBucket buck(aPos);
+  double lat = aPos.getLatitudeDeg(),
+    lon = aPos.getLongitudeDeg();
+  
+  int bx = (int)( aRange*SG_NM_TO_METER / buck.get_width_m() / 2);
+  int by = (int)( aRange*SG_NM_TO_METER / buck.get_height_m() / 2 );
+    
+  // loop over bucket range 
+  for ( int i=-bx; i<=bx; i++) {
+    for ( int j=-by; j<=by; j++) {
+      buck = sgBucketOffset(lon, lat, i, j);
+      
+      SpatialPositionedIndex::const_iterator it;
+      it = global_spatialIndex.find(buck.gen_index());
+      if (it == global_spatialIndex.end()) {
+        continue;
+      }
+      
+      BucketEntry::const_iterator l = std::lower_bound(it->second.begin(), it->second.end(), aLower, LowerLimitOfType());
+      BucketEntry::const_iterator u = std::upper_bound(l, it->second.end(), aUpper, LowerLimitOfType());
+      
+      for ( ; l != u; ++l) {
+        aResult.push_back(*l);
+      }
+      
+    } // of j-iteration
+  } // of i-iteration  
+}
+
+/**
+ * Cartesian range predicate. Note that for really long ranges, might need to
+ * to use geodetic / geocentric distance instead
+ */
+class RangePredictate
+{
+public:
+  RangePredictate(const Point3D& aOrigin, double aRange) :
+    mOrigin(aOrigin),
+    mRangeSquared(aRange * aRange)
+  { ; }
+  
+  bool operator()(const FGPositionedRef& aPos)
+  {
+    Point3D p(Point3D::fromSGGeod(aPos->geod()));
+    bool ok = (mOrigin.distance3Dsquared(p) > mRangeSquared);
+    if (ok) {
+      double x = sqrt(mOrigin.distance3Dsquared(p) - mRangeSquared);
+      x *= SG_METER_TO_NM;
+      //std::cout << "pos:" << aPos->ident() << " failed range check by " << x << std::endl;
+    }
+    return ok;
+  }
+  
+private:
+  Point3D mOrigin;
+  double mRangeSquared;
+};
+
+static void
+filterListByRange(const SGGeod& aPos, double aRange, FGPositioned::List& aResult)
+{
+  RangePredictate pred(Point3D::fromSGGeod(aPos), aRange * SG_NM_TO_METER);
+  FGPositioned::List::iterator newEnd; 
+  newEnd = std::remove_if(aResult.begin(), aResult.end(), pred);
+  aResult.erase(newEnd, aResult.end());
+}
+
+class DistanceOrdering
+{
+public:
+  DistanceOrdering(const SGGeod& aPos) :
+    mPos(Point3D::fromSGGeod(aPos))
+  { }
+  
+  bool operator()(const FGPositionedRef& a, const FGPositionedRef& b) const
+  {
+    return mPos.distance3Dsquared(Point3D::fromSGGeod(a->geod())) < 
+      mPos.distance3Dsquared(Point3D::fromSGGeod(b->geod()));
+  }
+
+private:
+  Point3D mPos;
+};
+
+static void
+sortByDistance(const SGGeod& aPos, FGPositioned::List& aResult)
+{
+  std::sort(aResult.begin(), aResult.end(), DistanceOrdering(aPos));
+}
+
+static FGPositionedRef
+namedFindClosestTyped(const std::string& aIdent, const SGGeod& aOrigin, 
+  FGPositioned::Type aLower, FGPositioned::Type aUpper)
+{
+  NamedIndexRange range = global_namedIndex.equal_range(aIdent);
+  if (range.first == range.second) return NULL;
+  
+// common case, only one result. looks a bit ugly because these are
+// sequential iterators, not random-access ones
+  NamedPositionedIndex::const_iterator check = range.first;
+  if (++check == range.second) {
+    // excellent, only one match in the range - all we care about is the type
+    FGPositioned::Type ty = range.first->second->type();
+    if ((ty < aLower) || (ty > aUpper)) {
+      return NULL; // type check failed
+    }
+    
+    return range.first->second;
+  } // of short-circuit logic for single-element range
+  
+// multiple matches, we need to actually check the distance to each one
+  double minDist = HUGE_VAL;
+  FGPositionedRef result;
+  Point3D origin(Point3D::fromSGGeod(aOrigin));
+  
+  for (; range.first != range.second; ++range.first) {
+  // filter by type
+    FGPositioned::Type ty = range.first->second->type();
+    if ((ty < aLower) || (ty > aUpper)) {
+      continue;
+    }
+    
+  // find distance
+    Point3D p(Point3D::fromSGGeod(range.first->second->geod()));
+    double ds = origin.distance3Dsquared(p);
+    if (ds < minDist) {
+      minDist = ds;
+      result = range.first->second;
+    }
+  }
+  
+  return result;
+}
+
+static FGPositioned::List
+spatialGetClosest(const SGGeod& aPos, unsigned int aN, double aCutoffNm, const FGPositioned::Filter& aFilter)
+{
+  FGPositioned::List result;
+  int radius = 1; // start at 1, radius 0 is handled explicitly
+  SGBucket buck;
+  double lat = aPos.getLatitudeDeg(),
+    lon = aPos.getLongitudeDeg();
+  // final cutoff is in metres, and scaled to account for testing the corners
+  // of the 'box' instead of the centre of each edge
+  double cutoffM = aCutoffNm * SG_NM_TO_METER * 1.5;
+  
+  // base case, simplifes loop to do it seperately here
+  spatialFilterInBucket(sgBucketOffset(lon, lat, 0, 0), aFilter, result);
+
+  for (;result.size() < aN; ++radius) {
+    // cutoff check
+    double az1, az2, d1, d2;
+    SGGeodesy::inverse(aPos, sgBucketOffset(lon, lat, -radius, -radius).get_center(), az1, az2, d1);
+    SGGeodesy::inverse(aPos, sgBucketOffset(lon, lat, radius, radius).get_center(), az1, az2, d2);  
+      
+    if ((d1 > cutoffM) && (d2 > cutoffM)) {
+      //std::cerr << "spatialGetClosest terminating due to range cutoff" << std::endl;
+      break;
+    }
+    
+    FGPositioned::List hits;
+    for ( int i=-radius; i<=radius; i++) {
+      spatialFilterInBucket(sgBucketOffset(lon, lat, i, -radius), aFilter, hits);
+      spatialFilterInBucket(sgBucketOffset(lon, lat, -radius, i), aFilter, hits);
+      spatialFilterInBucket(sgBucketOffset(lon, lat, i, radius), aFilter, hits);
+      spatialFilterInBucket(sgBucketOffset(lon, lat, radius, i), aFilter, hits);
+    }
+
+    result.insert(result.end(), hits.begin(), hits.end()); // append
+  } // of outer loop
+  
+  if (result.size() > aN) {
+    result.resize(aN); // truncate at requested number of matches
+  }
+  
+  sortByDistance(aPos, result);
+  return result;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+FGPositioned::FGPositioned() :
+  mType(INVALID)
+{
+}
+
+FGPositioned::FGPositioned(Type ty, const std::string& aIdent, double aLat, double aLon, double aElev) :
+  mType(ty),
+  mIdent(aIdent),
+  mPosition(SGGeod::fromDegFt(aLon, aLat, aElev))
+{
+  //addToIndices(this);
+  //SGReferenced::get(this); // hold an owning ref, for the moment
+}
+
+FGPositioned::FGPositioned(Type ty, const std::string& aIdent, const SGGeod& aPos) :
+  mType(ty),
+  mIdent(aIdent),
+  mPosition(aPos)
+{
+  //addToIndices(this);
+  //SGReferenced::get(this); // hold an owning ref, for the moment
+}
+
+FGPositioned::~FGPositioned()
+{
+  //std::cout << "~FGPositioned:" << mIdent << std::endl;
+  //removeFromIndices(this);
+}
+
+SGBucket
+FGPositioned::bucket() const
+{
+  return SGBucket(mPosition);
+}
+
+const char* FGPositioned::nameForType(Type aTy)
+{
+ switch (aTy) {
+ case FIX: return "fix";
+ case VOR: return "VOR";
+ case NDB: return "NDB";
+ case OM: return "outer-marker";
+ case MM: return "middle-marker";
+ case IM: return "inner-marker";
+ case AIRPORT: return "airport";
+ case HELIPORT: return "heliport";
+ case SEAPORT: return "seaport";
+ case WAYPOINT: return "waypoint";
+ default:
+  return "unknown";
+ }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// search / query functions
+
+FGPositionedRef
+FGPositioned::findClosestWithIdent(const std::string& aIdent, double aLat, double aLon)
+{
+  return findClosestWithIdent(aIdent, SGGeod::fromDeg(aLon, aLat));
+}
+
+FGPositionedRef
+FGPositioned::findClosestWithIdent(const std::string& aIdent, const SGGeod& aPos)
+{
+  return namedFindClosestTyped(aIdent, aPos, INVALID, LAST_TYPE);
+}
+
+FGPositioned::List
+FGPositioned::findWithinRangeByType(const SGGeod& aPos, double aRangeNm, Type aTy)
+{
+  List result;
+  spatialFindTyped(aPos, aRangeNm, aTy, aTy, result);
+  filterListByRange(aPos, aRangeNm, result);
+  return result;
+}
+
+FGPositioned::List
+FGPositioned::findWithinRange(const SGGeod& aPos, double aRangeNm, const Filter& aFilter)
+{
+  List result;
+  spatialFind(aPos, aRangeNm, aFilter, result);
+  filterListByRange(aPos, aRangeNm, result);
+  return result;
+}
+
+FGPositioned::List
+FGPositioned::findAllWithIdent(const std::string& aIdent)
+{
+  List result;
+  NamedIndexRange range = global_namedIndex.equal_range(aIdent);
+  for (; range.first != range.second; ++range.first) {
+    result.push_back(range.first->second);
+  }
+  
+  return result;
+}
+
+FGPositioned::List
+FGPositioned::findClosestN(const SGGeod& aPos, unsigned int aN, double aCutoffNm, const Filter& aFilter)
+{
+  return spatialGetClosest(aPos, aN, aCutoffNm, aFilter);
+}
+
diff --git a/src/Navaids/positioned.hxx b/src/Navaids/positioned.hxx
new file mode 100644
index 000000000..f6cf3cf37
--- /dev/null
+++ b/src/Navaids/positioned.hxx
@@ -0,0 +1,142 @@
+// positioned.hxx - base class for objects which are positioned 
+//
+// Copyright (C) 2008 James Turner
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+//
+// $Id$
+
+#ifndef FG_POSITIONED_HXX
+#define FG_POSITIONED_HXX
+
+#include <vector>
+
+#include <simgear/structure/SGSharedPtr.hxx>
+#include <simgear/bucket/newbucket.hxx>
+
+class FGPositioned;
+
+typedef SGSharedPtr<FGPositioned> FGPositionedRef;
+
+class FGPositioned : public SGReferenced
+{
+public:
+
+  typedef enum {
+    INVALID = 0,
+    AIRPORT,
+    HELIPORT,
+    SEAPORT,
+    RUNWAY,
+    TAXIWAY,
+    PARK_STAND,
+    FIX,
+    VOR,
+    NDB,
+    ILS,
+    LOC,
+    GS,
+    OM,
+    MM,
+    IM,
+    DME,
+    TACAN,
+    OBSTACLE,
+    WAYPOINT, // user-defined waypoint
+    FREQ_GND,
+    FREQ_TWR,
+    FREQ_ATIS,
+    LAST_TYPE
+  } Type;
+
+  typedef std::vector<FGPositionedRef> List;
+  
+  virtual ~FGPositioned();
+  
+  Type type() const
+  { return mType; }
+
+  const std::string& ident() const
+  { return mIdent; }
+
+  const SGGeod& geod() const
+  { return mPosition; }
+
+  SGBucket bucket() const;
+  
+  double latitude() const
+  { return mPosition.getLatitudeDeg(); }
+  
+  double longitude() const
+  { return mPosition.getLongitudeDeg(); }
+  
+  double elevation() const
+  { return mPosition.getElevationFt(); }
+  
+  /**
+   * Predicate class to support custom filtering of FGPositioned queries
+   */
+  class Filter
+  {
+  public:
+    virtual ~Filter() { ; }
+    
+    virtual bool pass(FGPositioned* aPos) const = 0;
+    
+    bool operator()(FGPositioned* aPos) const
+    { return pass(aPos); }
+  };
+  
+  static List findWithinRange(const SGGeod& aPos, double aRangeNm, const Filter& aFilter);
+      
+  static List findWithinRangeByType(const SGGeod& aPos, double aRangeNm, Type aTy);
+
+  static FGPositionedRef findClosestWithIdent(const std::string& aIdent, double aLat, double aLon);
+  
+  static FGPositionedRef findClosestWithIdent(const std::string& aIdent, const SGGeod& aPos);
+  
+  static List findAllWithIdent(const std::string& aIdent);
+  
+  /**
+   * Find the closest N items to a position, which pass the specified filter
+   * A cutoff range in NM must be specified, to constrain the search acceptably.
+   * Very large cutoff values will make this slow.
+   * 
+   * @result The matches (possibly less than N, depending on the filter and cutoff),
+  *    sorted by distance from the search pos
+   * @param aN - number of matches to find
+   * @param aCutoffNm - maximum distance to search within, in nautical miles
+   */
+  static List findClosestN(const SGGeod& aPos, unsigned int aN, double aCutoffNm, const Filter& aFilter);
+  
+  /**
+   * Debug helper, map a type to a human-readable string
+   */
+  static const char* nameForType(Type aTy);
+protected:
+  FGPositioned(Type ty, const std::string& aIdent, double aLat, double aLon, double aElev);
+  
+  FGPositioned(Type ty, const std::string& aIdent, const SGGeod& aPos);
+  
+  SGGeod mPosition; // can't be const right now
+  
+//private: // make private once FGFix and FGRunway are heap-based
+  FGPositioned();
+  
+  Type mType;
+  std::string mIdent;
+};
+
+#endif // of FG_POSITIONED_HXX