LazMapViewer: Remove drawing residues outside the map tiles. Patch by Yuliyan Ivanov.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@9142 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/lazmapviewer/examples/fulldemo/main.lfm

@@ -39,9 +39,9 @@ object MainForm: TMainForm
     Height = 640
     Top = 0
     Width = 275
-    ActivePage = PgConfig
+    ActivePage = PgData
     Align = alRight
-    TabIndex = 1
+    TabIndex = 0
     TabOrder = 1
     object PgData: TTabSheet
       Caption = 'Data'

components/lazmapviewer/source/mvde_intfgraphics.pas

@@ -473,8 +473,7 @@ var
   OldWidth: Integer;
   OldStyle: TPenStyle;
 begin
-  {$IF 0}
-  // TFPPixelCanvas.DoPolygonFill doesn't fill
+  {$IF FPC_FullVersion >= 30203}
   FCanvas.Polygon(Points);
   {$ELSE}
   if BrushStyle <> bsClear then

components/lazmapviewer/source/mvdrawingengine.pas

@@ -166,6 +166,13 @@ function OrthoVec(X1, Y1, X2, Y2: Integer; out MX, MY: Double): Boolean;
 var
   DX, DY: Integer;
   B: Double;
+
+  // Inverted vector magnitude
+  function InvMagn(X, Y: Double): Double; inline;
+  begin
+    Result := 1.0 / Sqrt(X * X + Y * Y);
+  end;
+
 begin
   if (Y1 = Y2) and (X1 = X2) then
     Exit(False);
@@ -180,20 +187,10 @@ begin
   else if DY = 0 then
     MX := 0.0 // <0.0, 1.0>
   else
-  begin // Quick and dirty...
-    if CompareValue(Abs(DY/DX), 1.0, 0.5) = 0
-      then B := 0.7
-      else B := 1.0;
-    MX := EnsureRange(-DY/DX, -B, B);
-    MY := EnsureRange(-DX/DY, -B, B);
-    if Sign(DX) = Sign(DY) then
-      MX := -MX;
-    {$IFDEF 0}
-    // The correct way
-    A := ArcTan2(-DX, DY);
-    MX := Cos(A);
-    MY := Sin(A);
-    {$IFEND}
+  begin
+    B := InvMagn(DX, DY);
+    MX := DY * B;
+    MY := -DX * B;
   end;
   Result := True;
 end;

components/lazmapviewer/source/mvengine.pas

@@ -115,7 +115,7 @@ type
       function DegreesToPixelsEPSG3395(const AWin: TMapWindow; ALonLat: TRealPoint): TPoint;
       function DegreesToPixelsEPSG3857(const AWin: TMapWindow; ALonLat: TRealPoint): TPoint;
       procedure Redraw(const aWin: TMapWindow; const paintOnly: Boolean = False);
-      function CalculateVisibleTiles(const aWin: TMapWindow) : TArea;
+      function CalculateVisibleTiles(const aWin: TMapWindow; out Area: TArea): Boolean;
       function IsCurrentWin(const aWin: TMapWindow) : boolean;
     protected
       procedure AdjustZoomCenter(var AWin: TMapWindow);
@@ -352,18 +352,36 @@ begin
   CalculateWin(AWin);
 end;
 
-function TMapViewerEngine.CalculateVisibleTiles(const aWin: TMapWindow): TArea;
+// Returns whether the view area is not covered fully with a tiles
+function TMapViewerEngine.CalculateVisibleTiles(const aWin: TMapWindow; out
+  Area: TArea): Boolean;
 var
   MaxX, MaxY, startX, startY: int64;
+  WorldSize: Int64;
 begin
-  MaxX := (Int64(aWin.Width) div TILE_SIZE) + 1;
-  MaxY := (Int64(aWin.Height) div TILE_SIZE) + 1;
+  Area := Default(TArea);
+  Result := True;
+  WorldSize := 1 shl AWin.Zoom;
+  MaxX := Int64(aWin.Width) div TILE_SIZE + 1;
+  MaxY := Int64(aWin.Height) div TILE_SIZE + 1;
+  if (MaxX > WorldSize) or (MaxY > WorldSize) then
+  begin
+    Result := False;
+    MaxX := Min(WorldSize - 1, MaxX);
+    MaxY := Min(WorldSize - 1, MaxY);
+  end;
   startX := -aWin.X div TILE_SIZE;
   startY := -aWin.Y div TILE_SIZE;
-  Result.Left := startX;// - 1;
-  Result.Right := startX + MaxX;
-  Result.Top := startY;// - 1;
-  Result.Bottom := startY + MaxY;
+  if (startX < 0) or (startY < 0) then
+  begin
+    startX := Max(0, -aWin.X div TILE_SIZE);
+    startY := Max(0, -aWin.Y div TILE_SIZE);
+    Result := False;
+  end;
+  Area.Left := startX;
+  Area.Right := startX + MaxX;
+  Area.Top := startY;
+  Area.Bottom := startY + MaxY;
 end;
 
 procedure TMapViewerEngine.CalculateWin(var AWin: TMapWindow);
@@ -1007,11 +1025,21 @@ var
     end;
   end;
 
+  procedure EraseBackground;
+  var
+    I, J: Integer;
+  begin
+    for J := 0 to (AWin.Height div TILE_SIZE) + 1 do
+      for I := 0 to (AWin.Width div TILE_SIZE) + 1 do
+        DrawTile(tile, I * TILE_SIZE, J * TILE_SIZE, Nil);
+  end;
+
 begin
   if not(Active) then
     Exit;
 
-  TilesVis := CalculateVisibleTiles(AWin);
+  if not CalculateVisibleTiles(AWin, TilesVis) then
+    EraseBackground;
   SetLength(Tiles, (TilesVis.Bottom - TilesVis.Top + 1) * (TilesVis.Right - TilesVis.Left + 1));
   iTile := Low(Tiles);
   numTiles := 1 shl AWin.Zoom;

components/lazmapviewer/source/mvjobqueue.pas

@@ -108,7 +108,7 @@ type
 implementation
 
 const
-  WAIT_TIME = 300;
+  WAIT_TIME = 150;
   TERMINATE_TIMEOUT = WAIT_TIME * 2;
 
 type
@@ -381,10 +381,11 @@ begin
   begin
     TerminateEvent := TEvent.Create(nil, false, false, '');
     try
-      FEvent.SetEvent;
       TerminatedThread := 0;
       for i := 0 to Pred(Threads.Count) do
         TQueueThread(Threads[i]).Terminate;
+      for i := 0 to Pred(Threads.Count) do
+        FEvent.SetEvent;
       TerminateEvent.WaitFor(TERMINATE_TIMEOUT);
       for i := 0 to Pred(Threads.Count) do
         TQueueThread(Threads[i]).WaitFor;