Re: GPoint Threshold: IE vs. Firefox

Running,

The critical factor is the opacity of the polyline. You are not
specifying it in your new GPolyline call, so it is assigned a default
value between 0 and 1. The default value is 0.45 in maps.29.js.

The polyline is drawn as though you were using a magic marker with
semitransparent ink, in this case, ink that passes 55% of the light
from the image below.

When you draw a polyline, you start by setting the marker tip down on
the starting point, and dragging to the end point. When you draw up to
a point, and then continue on (or start another polyline at that
point), visualize that fat marker depositing two layers of ink over the
point. Each layer has 45% opacity, so each passes 55% of the light from
below, for an effective transmission of 30.25% or an opacity of 69.75%.
This is much darker than the default opacity of 45%. Thus the dark spot
at each overlapping polyline end/start point. You will also see these
spots where two polylines cross.

This is one of the consequences of simple drawing with semi-transparent
'ink'. The work-around for long polylines in Firefox requires you to
break up long polylines, making this problem more visible.