notes on converting latlon to google maps tile

gistfile1.txt

;; work in progress!

(defn mf
  [lat lon zoom]
  (let [min-lat -90]))

(defn my-func
  [lat lon zoom]
  (let [tile-range (bit-shift-left 1 zoom)
        y lat
        x lon]
    (cond (or (< y 0) (>= y tile-range)) nil
          (or (< x 0) (>= x tile-range)) {:y y :x (mod
                                                   (+ tile-range
                                                      (mod x tile-range))
                                                   tile-range)})))

(defn normalize-lat
  [lat]
  (- lat -90))

(defn normalize-lon
  [lon]
  (- lon -180))

(defn calc-x
  [lon zoom]
  (let [tile-range (bit-shift-left 1 zoom)
        norm-lon (normalize-lon lon)
        norm-lat (normalize-lat)
        deg-x (/ 360 tile-range)
        deg-y (/ 180 tile-range)]
    (prn (str "deg-per-tile: " deg-x))
    (prn (str "normalized: " norm-lon))
    (int (/ norm-lon deg-x))))