From: mfranz <mfranz>
Date: Thu, 4 Oct 2007 17:11:19 +0000 (+0000)
Subject: when searching for the runway best matching a target heading, also consider
X-Git-Url: https://git.mxchange.org/?a=commitdiff_plain;h=d20db83c863ce45f7b785b8da00ca77cb3bfe851;p=flightgear.git

when searching for the runway best matching a target heading, also consider
the runway length/width/surface material, so that fgfs doesn't drop one on
the ridiculous grass stripe parallel to the grown up concrete runway
(LOWL, LOXZ, ...). The weighting factors are for now made configurable,
so that they are easier to adjust. This can later be made static.
(will soon get forward ported to fg/osg)
---

diff --git a/src/Airports/runways.cxx b/src/Airports/runways.cxx
index 70679c21f..89388fdb1 100644
--- a/src/Airports/runways.cxx
+++ b/src/Airports/runways.cxx
@@ -216,63 +216,78 @@ bool FGRunwayList::search( const string& aptid, const int tgt_hdg,
 
 
 // Return the runway number of the runway closest to a given heading
-string FGRunwayList::search( const string& aptid, const int tgt_hdg ) {
+#include <Main/fg_props.hxx>   // FIXME remove
+string FGRunwayList::search( const string& aptid, const int hdg ) {
+    //SG_LOG(SG_GENERAL, SG_DEBUG, "searching runway for " << aptid
+    //        << " with target heading " << hdg);
+
     FGRunway r;
-    FGRunway tmp_r;	
-    string rn;
-    double found_dir = 0.0;
-
-    if ( !search( aptid, &tmp_r ) ) {
-	SG_LOG( SG_GENERAL, SG_ALERT,
-                "Failed to find " << aptid << " in database." );
-	return "NN";
+    if (!search(aptid, &r)) {
+        SG_LOG(SG_GENERAL, SG_ALERT, "Failed to find "
+                << aptid << " in database.");
+        return "NN";
     }
-    
-    double diff;
-    double min_diff = 360.0;
-    
-    while ( tmp_r._id == aptid ) {
-	// forward direction
-	diff = tgt_hdg - tmp_r._heading;
-	while ( diff < -180.0 ) { diff += 360.0; }
-	while ( diff >  180.0 ) { diff -= 360.0; }
-	diff = fabs(diff);
-        // SG_LOG( SG_GENERAL, SG_INFO,
-        //	   "Runway " << tmp_r._rwy_no << " heading = "
-	//         << tmp_r._heading << " diff = " << diff );
-	if ((diff < min_diff) && (tmp_r._type == "runway")) {
-	    min_diff = diff;
-	    r = tmp_r;
-	    found_dir = 0;
-	}
-	
-	// reverse direction
-	diff = tgt_hdg - tmp_r._heading - 180.0;
-	while ( diff < -180.0 ) { diff += 360.0; }
-	while ( diff >  180.0 ) { diff -= 360.0; }
-	diff = fabs(diff);
-        // SG_LOG( SG_GENERAL, SG_INFO,
-        //	   "Runway -" << tmp_r._rwy_no << " heading = " <<
-        //	   tmp_r._heading + 180.0 <<
-        //	   " diff = " << diff );
-	if ((diff < min_diff) && (tmp_r._type == "runway")) {
-	    min_diff = diff;
-	    r = tmp_r;
-	    found_dir = 180.0;
-	}
-	
-        if (!next( &tmp_r ))
+
+    double LENWGT = fgGetDouble("/tmp/runway-search/length", 0.01);
+    double WIDWGT = fgGetDouble("/tmp/runway-search/width", 0.01);
+    double SURFWGT = fgGetDouble("/tmp/runway-search/surface", 10);
+    double DEVWGT = fgGetDouble("/tmp/runway-search/deviation", 1);
+
+    FGRunway best;
+    double max = 0.0;
+    bool reversed = false;
+
+    while (r._id == aptid) {
+        if (r._type != "runway")
+            continue;
+
+        int surface = 0;
+        if (r._surface_code == 1 || r._surface_code == 2)       // asphalt & concrete
+            surface = 2;
+        else if (r._surface_code == 12 || r._surface_code == 5) // dry lakebed & gravel
+            surface = 1;
+
+        double quality, bad, diff;
+        double good = LENWGT * r._length + WIDWGT * r._width + SURFWGT * surface;
+
+        // this side
+        diff = hdg - r._heading;
+        while (diff < -180)
+            diff += 360;
+        while (diff >= 180)
+            diff -= 360;
+        bad = DEVWGT * fabs(diff) + 1e-20;
+
+        quality = good / bad;
+        //SG_LOG(SG_GENERAL, SG_DEBUG, "  runway " << r._rwy_no <<  " -> " << quality);
+        if (quality > max) {
+            max = quality;
+            best = r;
+            reversed = false;
+        }
+
+        // other side
+        diff = hdg - r._heading - 180;
+        while (diff < -180)
+            diff += 360;
+        while (diff >= 180)
+            diff -= 360;
+        bad = DEVWGT * fabs(diff) + 1e-20;
+
+        quality = good / bad;
+        //SG_LOG(SG_GENERAL, SG_DEBUG, "  runway " << GetReverseRunwayNo(r._rwy_no)
+        //        <<  " -> " << quality);
+        if (quality > max) {
+            max = quality;
+            best = r;
+            reversed = true;
+        }
+
+        if (!next(&r))
             break;
     }
-    
-    // SG_LOG( SG_GENERAL, SG_INFO, "closest runway = " << r._rwy_no
-    //	       << " + " << found_dir );
-    rn = r._rwy_no;
-    if ( found_dir == 180 ) {
-	rn = GetReverseRunwayNo(rn);
-    }	
-    
-    return rn;
+
+    return reversed ? GetReverseRunwayNo(best._rwy_no) : best._rwy_no;
 }