Waypoint hiding support (for the A320, etc)

To support FMS which delete ‘past’ waypoints, add some helpers:
 - waypoints can be flagged as hidden, this property is exposed to Nasal
 - currentWP() accepts an offset parameter, allowing FlightPlan indexing
   to treat the current WP as index 0
 - a ‘numRemainingWaypoints()’ function on flightPlan in Nasal, again
   to range how many waypoints are left, starting from the current WP

Add some basic tests of these new features to the route-manager tests.

src/Navaids/route.hxx

@@ -76,7 +76,10 @@ typedef enum {
   WPT_APPROACH      = 1 << 11,
 
   /// waypoint prodcued by expanding a VIA segment
-  WPT_VIA           = 1 << 12
+  WPT_VIA           = 1 << 12,
+    
+    // waypoint should be hidden from maps, etc
+    WPT_HIDDEN      = 1 << 13
 } WayptFlag;
 
 typedef enum {

src/Navaids/routePath.cxx

@@ -942,16 +942,21 @@ SGGeodVec RoutePath::pathForIndex(int index) const
   SGGeodVec r;
   
   if (d->waypoints[index].skipped) {
-        return SGGeodVec();
+    return {};
+  }
+  
+  // don't show any path
+  if (w.wpt->flag(WPT_HIDDEN)) {
+    return {};
   }
   
   if (ty == "vectors") {
     // ideally we'd show a stippled line to connect the route?
-    return SGGeodVec();
+    return {};
   }
   
   if (ty == "discontinuity") {
-    return SGGeodVec(); // no points for a discontinuity of course
+    return {}; // no points for a discontinuity of course
   }
   
   if (ty == "via") {

src/Scripting/NasalPositioned.cxx

@@ -561,6 +561,8 @@ static const char* waypointCommonGetMember(naContext c, Waypt* wpt, const char*
     } else {
       *out = naNil();
     }
+  } else if (!strcmp(fieldName, "hidden")) {
+      *out = naNum(wpt->flag(WPT_HIDDEN));
   } else if (wpt->type() == "hold") {
     // hold-specific properties
     const auto hold = static_cast<Hold*>(wpt);
@@ -603,6 +605,9 @@ static bool waypointCommonSetMember(naContext c, Waypt* wpt, const char* fieldNa
       if (!naIsString(value)) naRuntimeError(c, "fly_type must be a string");
       bool flyOver = (strcmp(naStr_data(value), "flyOver") == 0);
       wpt->setFlag(WPT_OVERFLIGHT, flyOver);
+  } else if (!strcmp(fieldName, "hidden")) {
+      if (!naIsNum(value)) naRuntimeError(c, "wpt.hidden must be a number");
+      wpt->setFlag(WPT_HIDDEN, static_cast<int>(value.num) != 0);
   } else if (wpt->type() == "hold") {
       const auto hold = static_cast<Hold*>(wpt);
       if (!strcmp(fieldName, "hold_heading_radial_deg")) {
@@ -2834,7 +2839,17 @@ static naRef f_flightplan_currentWP(naContext c, naRef me, int argc, naRef* args
   if (!fp) {
     naRuntimeError(c, "flightplan.currentWP called on non-flightplan object");
   }
-  return ghostForLeg(c, fp->currentLeg());
+    
+  int index = fp->currentIndex();
+  if (argc > 0) {
+    index += static_cast<int>(naNumValue(args[0]).num);
+  }
+  
+  if ((index < 0) || (index >= fp->numLegs())) {
+    return naNil();
+  }
+      
+  return ghostForLeg(c, fp->legAtIndex(index));
 }
 
 static naRef f_flightplan_nextWP(naContext c, naRef me, int argc, naRef* args)
@@ -2855,6 +2870,21 @@ static naRef f_flightplan_numWaypoints(naContext c, naRef me, int argc, naRef* a
   return naNum(fp->numLegs());
 }
 
+static naRef f_flightplan_numRemainingWaypoints(naContext c, naRef me, int argc, naRef* args)
+{
+  FlightPlan* fp = flightplanGhost(me);
+  if (!fp) {
+    naRuntimeError(c, "flightplan.f_flightplan_numRemainingWaypoints called on non-flightplan object");
+  }
+  
+  // for an inactive flightplan, just reutnr the total number of WPs
+  if (fp->currentIndex() < 0) {
+    return naNum(fp->numLegs());
+  }
+  
+  return naNum(fp->numLegs() - fp->currentIndex());
+}
+
 static naRef f_flightplan_appendWP(naContext c, naRef me, int argc, naRef* args)
 {
   FlightPlan* fp = flightplanGhost(me);
@@ -3382,6 +3412,8 @@ naRef initNasalPositioned(naRef globals, naContext c)
     hashset(c, flightplanPrototype, "getPlanSize", naNewFunc(c, naNewCCode(c, f_flightplan_numWaypoints)));
     // alias to this name also
     hashset(c, flightplanPrototype, "numWaypoints", naNewFunc(c, naNewCCode(c, f_flightplan_numWaypoints)));
+    hashset(c, flightplanPrototype, "numRemainingWaypoints", naNewFunc(c, naNewCCode(c, f_flightplan_numRemainingWaypoints)));
+  
     hashset(c, flightplanPrototype, "appendWP", naNewFunc(c, naNewCCode(c, f_flightplan_appendWP)));
     hashset(c, flightplanPrototype, "insertWP", naNewFunc(c, naNewCCode(c, f_flightplan_insertWP)));
     hashset(c, flightplanPrototype, "deleteWP", naNewFunc(c, naNewCCode(c, f_flightplan_deleteWP)));

test_suite/unit_tests/Navaids/test_routeManager.cxx

@@ -11,6 +11,7 @@
 #include <Navaids/NavDataCache.hxx>
 #include <Navaids/navrecord.hxx>
 #include <Navaids/navlist.hxx>
+#include <Navaids/routePath.hxx>
 
 // we need a default GPS instrument, hard to test seperately for now
 #include <Instrumentation/gps.hxx>
@@ -360,6 +361,62 @@ void RouteManagerTests::testDefaultApproach()
     
 }
 
+void RouteManagerTests::testHiddenWaypoints()
+{
+    FlightPlanRef fp1 = makeTestFP("NZCH", "02", "NZAA", "05L",
+                                   "ALADA NS WB WN MAMOD KAPTI OH");
+    fp1->setIdent("testplan");
+    fp1->setCruiseFlightLevel(360);
+    
+    auto rm = globals->get_subsystem<FGRouteMgr>();
+    rm->setFlightPlan(fp1);
+    
+    auto gpsNode = globals->get_props()->getNode("instrumentation/gps", true);
+    CPPUNIT_ASSERT(!strcmp("obs", gpsNode->getStringValue("mode")));
+    
+    // FIXME: use real Nasal test macros soon
+    auto testNode = globals->get_props()->getNode("test-data", true);
+    
+    fp1->legAtIndex(3)->waypoint()->setFlag(WPT_HIDDEN);
+    
+    // ensure no visual path is generated for hidden waypoints
+    RoutePath path(fp1);
+    CPPUNIT_ASSERT(path.pathForIndex(3).empty());
+    
+    
+    bool ok = FGTestApi::executeNasal(R"(
+        var fp = flightplan(); # retrieve the global flightplan
+        setprop("/test-data/a", fp.numRemainingWaypoints());
+    )");
+    CPPUNIT_ASSERT(ok);
+    CPPUNIT_ASSERT_EQUAL(fp1->numLegs(), testNode->getIntValue("a"));
+    
+    rm->activate();
+    fp1->setCurrentIndex(2);
+    
+    ok = FGTestApi::executeNasal(R"(
+        var fp = flightplan(); # retrieve the global flightplan
+        setprop("/test-data/a", fp.numRemainingWaypoints());
+        setprop("/test-data/b", fp.currentWP(2).id);
+    )");
+    
+    CPPUNIT_ASSERT(ok);
+    CPPUNIT_ASSERT_EQUAL(7, testNode->getIntValue("a"));
+    CPPUNIT_ASSERT_EQUAL(std::string{"WN"}, std::string{testNode->getStringValue("b")});
+    
+    ok = FGTestApi::executeNasal(R"(
+        var fp = flightplan(); # retrieve the global flightplan
+        setprop("/test-data/c", fp.currentWP(-1).id);
+                                 
+        # ensure invalid offset returns nil
+        setprop("/test-data/d", fp.currentWP(-100) == nil);
+    )");
+    
+    CPPUNIT_ASSERT(ok);
+    CPPUNIT_ASSERT_EQUAL(std::string{"ALADA"}, std::string{testNode->getStringValue("c")});
+    CPPUNIT_ASSERT_EQUAL(true, testNode->getBoolValue("d"));
+}
+
 void RouteManagerTests::testHoldFromNasal()
 {
    // FGTestApi::setUp::logPositionToKML("rm_hold_from_nasal");

test_suite/unit_tests/Navaids/test_routeManager.hxx

@@ -39,6 +39,7 @@ class RouteManagerTests : public CppUnit::TestFixture
     CPPUNIT_TEST(testDirectToLegOnFlightplanAndResume);
     CPPUNIT_TEST(testHoldFromNasal);
     CPPUNIT_TEST(testSequenceDiscontinuityAndResume);
+    CPPUNIT_TEST(testHiddenWaypoints);
     
     CPPUNIT_TEST_SUITE_END();
 
@@ -60,6 +61,7 @@ public:
     void testDirectToLegOnFlightplanAndResume();
     void testHoldFromNasal();
     void testSequenceDiscontinuityAndResume();
+    void testHiddenWaypoints();
 private:
     GPS* m_gps = nullptr;
 };