FIX apparent wind angle for WindBarbsOnRoute

seandepagnier · Sep 6, 2018 · d20dc09 · d20dc09
1 parent f8c3122
commit d20dc09
Showing 1 changed file with 4 additions and 3 deletions.
diff --git a/src/RouteMapOverlay.cpp b/src/RouteMapOverlay.cpp
@@ -726,13 +726,14 @@ void RouteMapOverlay::RenderWindBarbsOnRoute(wrDC &dc, PlugIn_ViewPort &vp)
         GetCanvasPixLL(&nvp, &p, it->lat, it->lon);
 
         // Calculate apparent wind direction
-        float apparentWindSpeed = Polar::VelocityApparentWind(it->VB, it->W, it->VW);
-        float apparentWindDirection = Polar::DirectionApparentWind(apparentWindSpeed, it->VB, it->W, it->VW);
+        float windDirection = heading_resolve(it->B - it->W);
+        float apparentWindSpeed = Polar::VelocityApparentWind(it->VB, windDirection, it->VW);
+        float apparentWindDirection = Polar::DirectionApparentWind(apparentWindSpeed, it->VB, windDirection, it->VW);
 
         // Draw barbs
         g_barbsOnRoute_LineBufferOverlay.pushWindArrowWithBarbs(
             wind_barb_route_cache, p.x, p.y, apparentWindSpeed,
-            deg2rad(apparentWindDirection) + nvp.rotation, it->lat < 0, true
+            deg2rad(positive_degrees(apparentWindDirection - it->B)) + nvp.rotation, it->lat < 0, true
         );
     }
     wind_barb_route_cache.Finalize();