MapView: virtual lines with dashes patterns are freezing scrolling.

[lolgear]

GitUp at latest master.
macOS 10.14.6.
MacBook Pro 15'', Mid 2015.

#415

[lolgear]

I have a lot of branches: 24.
Most of them doesn't have commits at top of map view.
~10 of them are virtual.

If I remove dashes pattern from them, map view will scroll pretty good.

      if (virtualLine) {
        const CGFloat pattern[] = {4, 2};
//        CGContextSetLineDash(context, 0, pattern, 2);
      }
      _DrawLine(line, context, offset, dirtyRect.origin.y, dirtyRect.origin.y + dirtyRect.size.height);
      if (virtualLine) {
//        CGContextSetLineDash(context, 0, NULL, 0);
      }

If I don't remove these dashes pattern, map view will freeze a lot while scrolling.

[lolgear]

Maybe it is better to remove dashes and/or add another feature to distinguish virtual branches and ordinary branches? ( Alpha, some color or background? )