In traffic they use parallel lines, but these are rendered as image tiles by a server. I would be curious to see how fast parallel lines could be in javascript. You may want to try changing your polyline coordinates on map event zoom_changed.
On 8 Jul 2010 19:38, "Enrico" <[email protected]> wrote: > Thank you for your fast reply Ben, > > I think that the solution of black poly is easy but I try it in a > small page that I have in local to pick the coords of polyline paths, > and when I have a closest zoom the two lines are too far and not seem > a two directions streets. furthermore if i use a large zoom, they > merge into 1 (and the black separator is over the only that I see). > > I see that it's possible to trigger the change zoom level on map, so I > think to control it and change the thickness of lines or change the > offset, but y have a lot of small polyline (like traffic, each one > with different color) and i must change all. I think in an array of > polyline and a for to change alls, but it seems a very expansive > process... > > I just find an example of drawing parallel lines (http:// > wtp2.appspot.com/ParallelLines.htm) and I think that i can use the > alghoritm to calculate the coords of one of two polylines every time > that i change zoom. I think it can work but it seems more expansive > that the other. > > In traffic seems that they use polygons, not polyline, but seems that > they can control the thickness. > Any idea? > > Thank! > > On 8 jul, 10:50, Ben Appleton <[email protected]> wrote: >> It sounds like you need your 2 Polylines to stay a minimum distance apart as >> you zoom out, so they don't merge into 1 line. A simple hack would be to >> render a thin opaque black Polyline down the middle of the road with a >> higher zIndex - that would divide the 2 Polylines. Another alternative >> would be to offset the 2 Polylines in JS, but that would be complex and >> slower. >> >> Good luck! >> Ben >> >> On 8 Jul 2010 18:28, "Enrico" <[email protected]> wrote: >> Hi, >> I start to play with API v3 and I have a conceptual problem: >> I need something like traffic overlay but with own data. >> Basically I need to print two line (one for every direction of a >> street) and dynamically change the color. >> >> The main problem is what can I use for this: polyline or polygons? >> - with polyline the thickness of it is the same in every zoom level >> so, if i see two lines in zoom level 8, i see only one on 15 because >> they are overlapped. >> - with polygon on zoom 15 (f.e.) i can't see them because are too >> small (i try to print a path with thickness 1 and printed like a >> street) >> >> I try to understand what use google in traffic but I can't. >> >> Any help? >> >> I will use javascript API v3 >> >> Thank! >> >> -- >> 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]<google-maps-js-api-v3%[email protected]><google-maps-js-api-v3%2B [email protected]> >> . >> For more options, visit this group athttp:// groups.google.com/group/google-maps-js-api-v3?hl=en. > > -- > 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]<google-maps-js-api-v3%[email protected]> . > For more options, visit this group at http://groups.google.com/group/google-maps-js-api-v3?hl=en. > -- 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.
