Fix date line breaks with non geographic input CRS

qgis · Jan 8, 2019 · e286c09 · e286c09
1 parent 654d7a4
commit e286c09
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Showing 2 changed files with 4 additions and 2 deletions.
diff --git a/src/core/qgsdistancearea.cpp b/src/core/qgsdistancearea.cpp
@@ -560,6 +560,7 @@ QList< QList<QgsPointXY> > QgsDistanceArea::geodesicLine( const QgsPointXY &p1,
   currentPart << p1;
   double d = interval;
   double prevLon = p1.x();
+  double prevLat = p1.y();
   bool lastRun = false;
   double t = 0;
   while ( true )
@@ -582,7 +583,7 @@ QList< QList<QgsPointXY> > QgsDistanceArea::geodesicLine( const QgsPointXY &p1,
       // when breaking the geodesic at the date line, we need to calculate the latitude
       // at which the geodesic intersects the date line, and add points to both line segments at this latitude
       // on the date line.
-      double lat180 = latitudeGeodesicCrossesDateLine( currentPart.constLast(), QgsPointXY( lon, lat ) );
+      double lat180 = latitudeGeodesicCrossesDateLine( QgsPointXY( prevLon, prevLat ), QgsPointXY( lon, lat ) );
 
       try
       {
@@ -621,6 +622,7 @@ QList< QList<QgsPointXY> > QgsDistanceArea::geodesicLine( const QgsPointXY &p1,
     }
 
     prevLon = lon;
+    prevLat = lat;
 
     try
     {

diff --git a/tests/src/python/test_qgsdistancearea.py b/tests/src/python/test_qgsdistancearea.py
@@ -723,7 +723,7 @@ def testGeodesicLine(self):
         g = QgsGeometry.fromMultiPolylineXY(da.geodesicLine(QgsPointXY(-13536427, 14138932), QgsPointXY(13760912, -13248201),
                                                             1000000, True))
         self.assertEqual(g.asWkt(0),
-                         'MultiLineString ((-13536427 14138932, -16514348 11691516, -17948849 9406595, -18744235 7552985, -19255354 6014890, -19622372 4688888, -19909239 3505045),(19925702 2415579, 19712755 1385803, 19513769 388441, 19318507 -600065, 19117459 -1602293, 18899973 -2642347, 18651869 -3748726, 18351356 -4958346, 17960498 -6322823, 17404561 -7918366, 16514601 -9855937, 14851845 -12232940, 13760912 -13248201))')
+                         'MultiLineString ((-13536427 14138932, -16514348 11691516, -17948849 9406595, -18744235 7552985, -19255354 6014890, -19622372 4688888, -19909239 3505045, -20037508 2933522),(20037508 2933522, 19925702 2415579, 19712755 1385803, 19513769 388441, 19318507 -600065, 19117459 -1602293, 18899973 -2642347, 18651869 -3748726, 18351356 -4958346, 17960498 -6322823, 17404561 -7918366, 16514601 -9855937, 14851845 -12232940, 13760912 -13248201))')
 
 
 if __name__ == '__main__':