Merge pull request #4101 from IvanSavenko/memory_usage_fix

[1.5.3] Reduce memory usage of adventure map

client/mapView/MapViewModel.cpp

@@ -102,7 +102,7 @@ int3 MapViewModel::getTileAtPoint(const Point & position) const
 
 Point MapViewModel::getCacheDimensionsPixels() const
 {
-	return getTilesVisibleDimensions() * getSingleTileSizeUpperLimit();
+	return getPixelsVisibleDimensions() + getSingleTileSizeUpperLimit() * 2;
 }
 
 Rect MapViewModel::getCacheTileArea(const int3 & coordinates) const