LazMapviewer: Partial fix of gps points created near E/W border not showing.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@8798 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/lazmapviewer/source/mvmapviewer.pas

@@ -793,8 +793,7 @@ var
 begin
   Area.TopLeft := Engine.ScreenToLonLat(Point(aLeft, aTop));
   Area.BottomRight := Engine.ScreenToLonLat(Point(aRight, aBottom));
-  while Area.BottomRight.Lon < Area.TopLeft.Lon do
-    Area.BottomRight.Lon := Area.BottomRight.Lon + 360.0;
+  Area.Normalize;
 
   if GPSItems.Count > 0 then
   begin
@@ -1016,13 +1015,25 @@ end;
 function TMapView.GetVisibleArea: TRealArea;
 var
   aPt: TPoint;
+  w, mapWidth: Int64;
 begin
   aPt.X := 0;
   aPt.Y := 0;
   Result.TopLeft := Engine.ScreenToLonLat(aPt);
-  aPt.X := Width;
-  aPt.Y := Height;
-  Result.BottomRight := Engine.ScreenToLonLat(aPt);;
+
+  mapWidth := ZoomFactor(Engine.Zoom) * TILE_SIZE;
+  w := Width;
+  if w >= mapWidth then
+  begin
+    Result.TopLeft.Lon := -180;
+    Result.BottomRight.Lon := 180;
+  end else
+  begin
+    aPt.X := w;
+    aPt.Y := Height;
+    Result.BottomRight := Engine.ScreenToLonLat(aPt);
+    Result.Normalize;
+  end;
 end;
 
 procedure TMapView.ClearBuffer;

components/lazmapviewer/source/mvtypes.pas

@@ -47,11 +47,15 @@ Type
   TRealArea = Record
     TopLeft : TRealPoint;
     BottomRight : TRealPoint;
+    procedure Normalize;
+    function Normalized: TRealArea;
   end;
 
 
 implementation
 
+{ TRealPoint }
+
 function TRealPoint.GetLonRad: Extended;
 begin
   Result := DegToRad(Self.Lon);
@@ -72,5 +76,19 @@ begin
   Self.Lat := RadToDeg(AValue);
 end;
 
+{ TRealArea }
+
+procedure TRealArea.Normalize;
+begin
+  while BottomRight.Lon < TopLeft.Lon do
+    BottomRight.Lon := BottomRight.Lon + 360.0;
+end;
+
+function TRealArea.Normalized: TRealArea;
+begin
+  Result := Self;
+  Result.Normalize;
+end;
+
 end.