ptl tool fixed, now works correctly regardless of rotation settings

Author: ronyan

CSiTRadar.cpp

@@ -145,7 +145,7 @@ void CSiTRadar::OnRefresh(HDC hdc, int phase)
 
 			// Draw PTL
 			if (hasPTL.find(radarTarget.GetCallsign()) != hasPTL.end()) {
-				HaloTool::drawPTL(&dc, radarTarget, p, 3, pixnm);
+				HaloTool::drawPTL(&dc, radarTarget, this, p, 3);
 			}
 
 			// Get information about the Aircraft/Flightplan

HaloTool.h

@@ -11,60 +11,74 @@ class HaloTool :
 {
 public:
 
-    static void drawHalo(CDC* dc, POINT p, double r, double pixpernm) 
+    static inline double degtorad(double deg) {
+        double ans = deg * PI / 180;
+        return ans;
+    }
+
+    static CPosition calcPTL(CPosition origin, double ptlLen, double gs, double bearing) {
+        double lat2;
+        double long2;
+        double earthRad = 3440; // in nautical miles
+
+        lat2 = asin(sin(origin.m_Latitude * PI / 180) * cos((ptlLen * gs / 60) / earthRad) + cos(origin.m_Latitude * PI / 180) * sin((ptlLen * gs / 60) / earthRad) * cos(bearing * PI / 180));
+        long2 = degtorad(origin.m_Longitude) + atan2((sin(bearing * PI / 180)) * sin((ptlLen * gs / 60) / earthRad) * cos(origin.m_Latitude * PI / 180), (cos(sin(bearing * PI / 180) / earthRad) - sin(origin.m_Latitude * PI / 180) * sin(lat2)));
+        CPosition ptlEnd;
+
+        ptlEnd.m_Latitude = lat2 * 180 / PI;
+        ptlEnd.m_Longitude = long2 * 180 / PI;
+
+        return ptlEnd;
+    };
+
+    static double calcBearing(CPosition origin, CPosition end) {
+        double y = sin(degtorad(end.m_Longitude) - degtorad(origin.m_Longitude)) * cos(degtorad(end.m_Latitude));
+        double x = cos(degtorad(origin.m_Latitude)) * sin(degtorad(end.m_Latitude)) - sin(degtorad(origin.m_Latitude)) * cos(degtorad(end.m_Latitude)) * cos(degtorad(end.m_Longitude) - degtorad(origin.m_Longitude));
+        double phi = atan2(y, x);
+        double bearing = fmod((phi * 180 / PI + 360), 360);
+
+        return bearing;
+    }
+
+    static void drawHalo(CDC* dc, POINT p, double r, double pixpernm)
     {
         int sDC = dc->SaveDC();
 
         //calculate pixels per nautical mile
 
         int pixoffset = (int)round(pixpernm * r);
 
-       // draw the halo around point p with radius r in NM
+        // draw the halo around point p with radius r in NM
         COLORREF targetPenColor = RGB(202, 205, 169);
         HPEN targetPen = CreatePen(PS_SOLID, 1, targetPenColor);
         dc->SelectObject(targetPen);
         dc->SelectStockObject(HOLLOW_BRUSH);
-        dc->Ellipse(p.x - pixoffset, p.y - pixoffset, p.x + pixoffset, p.y + pixoffset); 
+        dc->Ellipse(p.x - pixoffset, p.y - pixoffset, p.x + pixoffset, p.y + pixoffset);
 
         DeleteObject(targetPen);
-        
+
         dc->RestoreDC(sDC);
     };
 
-    static void drawPTL(CDC* dc, CRadarTarget radtar, POINT p, double ptlTime, double pixpernm)
+    static void drawPTL(CDC* dc, CRadarTarget radtar, CRadarScreen* radscr, POINT p, double ptlTime)
     {
         int sDC = dc->SaveDC();
-        
-        double theta = (radtar.GetTrackHeading() + CSiTRadar::magvar) * PI / 180;
-        double ptlDistance = radtar.GetGS() / 60 * ptlTime * pixpernm; 
-        double ptlYdelta = -cos(theta) * ptlDistance;
-        double ptlXdelta = sin(theta) * ptlDistance;
+
+        CPosition pos1 = radtar.GetPreviousPosition(radtar.GetPosition()).GetPosition();
+        CPosition pos2 = radtar.GetPosition().GetPosition();
+        double theta = calcBearing(pos1, pos2);
+        CPosition ptl = calcPTL(radtar.GetPosition().GetPosition(), ptlTime, radtar.GetPosition().GetReportedGS(), theta);
+        POINT p2 = radscr->ConvertCoordFromPositionToPixel(ptl);
 
         COLORREF targetPenColor = C_PTL_GREEN;
         HPEN targetPen = CreatePen(PS_SOLID, 1, targetPenColor);
         dc->SelectObject(targetPen);
 
         dc->MoveTo(p);
-        dc->LineTo(p.x + (int)round(ptlXdelta), p.y + (int)round(ptlYdelta));
+        dc->LineTo(p2);
 
         DeleteObject(targetPen);
 
         dc->RestoreDC(sDC);
     };
-
-    static CPosition calcPTL(CPosition origin, double ptlLen, double gs, double bearing) {
-        double lat2;
-        double long2;
-        double earthRad = 3440; // in nautical miles
-
-        lat2 = asin(sin(origin.m_Latitude * PI / 180) * cos((ptlLen * gs / 60) / earthRad) + cos(origin.m_Latitude * PI / 180) * sin((ptlLen*gs/60) / earthRad) * cos(bearing * PI/180));
-        long2 = origin.m_Longitude + atan2((sin(bearing * PI / 180)) * sin((ptlLen * gs / 60) / earthRad) * cos(origin.m_Latitude * PI / 180), (cos(sin(bearing * PI / 180) / earthRad) - sin(origin.m_Latitude * PI / 180) * sin(lat2)));
-        CPosition ptlEnd;
-
-        ptlEnd.m_Latitude = lat2 * 180 / PI;
-        ptlEnd.m_Longitude = long2 * 180 / PI;
-        
-        return ptlEnd;
-    };
 };
-