if: pixel = tilexy * tilesize and: res = ll / pixel
then: ll = res*pixel if: tilesize = 300 and: tilexy is always offset by 0.5 (the center) then: lat = (tiley + 0.5) * 300 * res lon = (tilex + 0.5) * 300 * res but because we don't view the world upside down, i.e. latitude increases as y decreases.. lat = (-tiley + 0.5) * 300 * res lon = (tilex + 0.5) * 300 * res Kenny France wrote: > Hi Guys, > > Im finally getting somewhere with the help of Chris Adams (Thanks Again) > > I have a map gererated, that is going to ultimatly grab image tiles > from my server > > I now know that if my tile is 300 Px and i need a resoloution of 5,12 > dd the calculation is > 5.12 / 300 = 0.017066667 > > In my sample i am simply displaying the pink tiles for now, but it is > trying to pull from my url, using the getfile function in the example > > so it shows get_tile.php?z=1&x=21&y=28 > > where z = zoom > x = tile number in the x position > y = tile number in the y position > > No by knowing the zoom level tile number etc, how could i calculate > the center lat/lng of the tile needed? > I thought it would be simple but how will i figure out if the lat/lng > are negitive values > > Please help me once again > > K- > > ------------------------------------------------------------------------ > I am using the free version of SPAMfighter for private users. > It has removed 38312 spam emails to date. > Paying users do not have this message in their emails. > Try SPAMfighter <http://www.spamfighter.com/len> for free now! > ------------------------------------------------------------------------ > > _______________________________________________ > Users mailing list > [email protected] > http://openlayers.org/mailman/listinfo/users > _______________________________________________ Users mailing list [email protected] http://openlayers.org/mailman/listinfo/users
