Question

If one is dealing with hundreds of polylines, would there be a big performance benefit to encoding the polylines using https://developers.google.com/maps/documentation/utilities/polylinealgorithm?hl=sv-SE

It seems that this is mostly used with API v2 and v3 handles large amounts of polylines on its own fairly well?

I can’t seem to find any benchmark comparisons.

Answer 1

There is a substantial gain when using google.maps.geometry.encoding.decodePath() to decode encoded paths when adding a polyling/polygon to a google map. I have a couple of paths with over a thousand points, and instead of looping through each point and creating a LatLng to be added to a Polygon, a simple decode loads visually quicker.

Additionally as Salman pointed out, there can be a substantial gain by reducing network traffic for passing paths via Ajax. Take google’s example:

Characters
0        1         2         3         4         5         6         7
1234567890123456789012345678901234567890123456789012345678901234567890
38.5,-120.2|40.7,-120.95|43.252,-126.453  // Polyline Decoded: 40 chars
_p~iF~ps|U_ulLnnqC_mqNvxq`@               // Polyline Encoded: 27 chars

With only 3 points we’ve reduced the the size of the points by 33%.