Hi Mike, When you said:
"Or you could just do an approximate calculation, based on the fact that 360 degrees of longitude are 256*(2^zoom) pixels and 170 degrees of latitude are also 256*(2^zoom) pixels." I think you answered my question about the zoom mathematics, and I can take it from here. Thanks! - - Bill On Feb 3, 11:37 am, Mike Williams <nos...@econym.demon.co.uk> wrote: > Wasn't it Bill who wrote: > > > > > > >Hi qFox, > > >I believe you may have misunderstood my question. I'm not trying to > >determine whether the polygon will fit inside the current zoom level, > >but rather whether the polygon will be so small that it's not worth > >drawing. > > >For example, there is no purpose in drawing an acre or a hectare when > >you are looking at the entire continent of North America. > > >So I'm trying to store a minimum visible zoom level for each polygon > >-- not the maximum visible zoom level, as map.getBoundsZoomLevel() > >would give me. > > >I assume this would involve some Mercator math, some long/lat to > >pixel, and some knowledge of how the zoom mathematics work... ideally, > >maybe we could discuss this in a platform-agnostic, pure math formula > >way? So then it could be implemented in PHP, Java, Ruby, etc. > > You could calculate the pixel bounds exactly in your server language, > then decide to ignore any that are smaller than a certain number of > pixels. Algorithms for doing server-side latlng to pixel has been posted > several times on this group. [I guess you're as capable of searching for > it as I am.] > > Or you could just do an approximate calculation, based on the fact that > 360 degrees of longitude are 256*(2^zoom) pixels and 170 degrees of > latitude are also 256*(2^zoom) pixels. > > --http://econym.org.uk/gmap > The Blackpool Community Church Javascript Team --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Maps API" group. To post to this group, send email to Google-Maps-API@googlegroups.com To unsubscribe from this group, send email to google-maps-api+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/Google-Maps-API?hl=en -~----------~----~----~----~------~----~------~--~---
