This code path is taken only for XOR mode on external monitor (or with uiScale=1.0 on retina monitor)

I have fixed the visual traces with poly-line drawn in XOR mode as a fix of JDK-8251167. That fix is not optimal as it draws N line segments separately.
This can be optimized as follows -
1. Apply magic numbers for the pixel alignment to the points of the poly-line and store the new values
2. Use these new values to draw poly-line preferably using line-strip or line-list.