Iterate through all image tiles for a given bounds and zoom range

map_tile_iterator.js

// Iterate through all map tiles for a given bounds and zoom range
// lat-lon to tile conversions from http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#Derivation_of_tile_names

function lat2tile(lat, zoom)  { 
  return (Math.floor((1-Math.log(Math.tan(lat*Math.PI/180) + 1/Math.cos(lat*Math.PI/180))/Math.PI)/2 *Math.pow(2,zoom)))
}

function lon2tile(lon, zoom) { 
  return (Math.floor((lon+180)/360*Math.pow(2,zoom)))
}

function iterator(z, x, y) {
  console.log(z + '/' + x + '/' + y + '.png')
  // do something more useful, like copy to s3
}

var lat_min = 42.5
var lat_max = 43.5
var lon_min = -80
var lon_max = -75
var z_min   = 8
var z_max   = 8
var total   = 0

for (var z = z_min; z < z_max + 1; z++) {
  var y_min = lat2tile(lat_max, z)  // 0,0 is top left
  var y_max = lat2tile(lat_min, z)
  var x_min = lon2tile(lon_min, z)
  var x_max = lon2tile(lon_max, z)
  for (var x = x_min; x < x_max + 1; x++) {
    for (var y = y_min; y < y_max + 1; y++) {
      iterator(z, x, y)
      total++
    }
  }
}
console.log(total)