On Jul 14, 12:31 am, William <[email protected]> wrote: > On Jul 12, 1:40 am, bratliff <[email protected]> wrote: > > > It seems to me you will have to determine the tangent at each vertex > > in order to have a fixed displacement from each vertex along the > > perpendicular to the tangent. It requires interpolation along each of > > two line segments connecting each vertex with its two immediate > > neighbors in order to have two equidistant verticies from which the > > tangent can be determined. It is feasible. It is a lot of overhead > > for JavaScript. > > yeah that's what the example does, but the fixed displacement is in > mercator units (map pixels) and the polylines are stored in latlngs, > so there's large overhead reprojecting the data. To remove the > reprojection overhead, I'll do an example with the data in mercator > using raw SVG/VML. > > This will also give a performance comparison with the V3 > google.maps.Polyline, which is a heavyweight implementation. I am sure > that javascript will be quick enough for the parallel calculations.
You may have to determine the centroid for the shape in order to always displace away / toward the center of gravity. Otherwise, transitions from convex to concave will cause the parallel line to cross the original line. -- You received this message because you are subscribed to the Google Groups "Google Maps JavaScript API v3" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-maps-js-api-v3?hl=en.
