Python实现

Question

我从以下网址获得了json响应：

http://maps.googleapis.com/maps/api/directions/json?origin=Chicago,IL&destination=Los%20Angeles,CA&sensor=false

JSON路径routes[x].legs[y].steps[z].polyline.points：

“azq〜FHC {uOAlB jB表示^ P P乙@ V□的|？？？？？？【J @为fA XA @ XA H +乙˚F@ TA @的xD H + BNA @ |？？？？？甲@ rB中@频率@ @@ d v□的AXB d @ AZEzA BIjB @Cx @ EzAAlC F F T B˚F@ DhHBhD 5 R升5 R |？？？？？？？？？？？？？？？CCpDAj @ E |？DGnDKzCCb @ OtBa @ rFGfAAb @ FAP @ ADbJD|F@bF@@@fERhd@BrEFdDBtBAvBAx@@l@?n@@^@bANnQ?rABnM?jC?hH@fA?@B F到VC的hB @BpM @Ĵ@@ p @@ |？？？？？？？KB〜Q因子@ pFBbHBvF @ Z @频率@@ jB表示？nA的@ Z @ DZD @ VJ〜CLFC \ |？？？？？？？？E B @ HnANtAVpDRpCLbB ^ dFTxC @ LZvDF ^ HrALlCH EB|H?DBpEB~V?^BhDJ - [R @@ \〜甲nABrL @ JD @ VD @ vA型H + ？BLx的[？X @ 2 B 4 \·F @ pA的2 H @ d〜H + @的Bz @ RbCLfA博士\ rBPv @@@ T〜@ T @ bCPf @ Z @ XBD @ RAF @分贝\咱〜@ PjAT〜BFrADxAH X?z@?@HfW?x@?F?@@dD@^F|Y@v@D|JBzH?rB@tAApABxB?bA@dBBxABlAJ~CJrBDfANhBNjCLlCLpBHlBFnB@℃|？？？？A v @ AlBCdA R 6 EJEC | BItEMdGEtAIfEI |？BKzDOzGEjCCl @ MnDW HSrFSlFAd@?@qA|[Ct@Cj@At@AbA?hBAdBClBQjFQnECr@E AYjFIzAWxDQpCYpEAFItACt @ S〜C] |？GSlEMnCMtCGdAKlBQxDg @ BLAT BKrCAn @广告@ X @ 2P @Ĵ|？？？？@@ 1A中@ Z @ BbABn @ @@的Bt @HnAPxB@LB^L的{{1}} AP〜@ Z〜ALN @ @@ @的Fd |？BjAfGd @ DDD @ | d \ BFDF @ d〜@@ @˚FC |？@@ XCJ BP EDtE @ bADlAR P?dBB {@ {1}} ADhLBbD @ X @频率@〜çdCNbTDrIBxDLbO @〜AV {{1} } FHX @ H |？@ EJlABh@Dp@F DBLC @ @@Ĵ@ĴBhAHhLBvC 2P @ BLB jAAfAAx @ 13 C @xEJdBHlCF~C@nA?@?@DfG? AOpAKfAEp @ GZ @ @的Cb @ GpACZAVAh广告@ AX˚F@在@的CpB”？

我想解码Polyline点字符串以使用PHP来转换上述URL返回的长值。

我在Java和Objective C中找到了一些结果，但我需要在PHP中使用它。

Answer 1

Python实现

这不是在PHP中，但如果您要从Google地图解码折线字符串，则此主题位于搜索结果的顶部附近。如果其他人需要它（就像我做的那样），这里有一个用于解码折线字符串的Python实现。这是从Mapbox JavaScript版本移植而来的;在repo page.

上找到更多信息

def decode_polyline(polyline_str):
    index, lat, lng = 0, 0, 0
    coordinates = []
    changes = {'latitude': 0, 'longitude': 0}

    # Coordinates have variable length when encoded, so just keep
    # track of whether we've hit the end of the string. In each
    # while loop iteration, a single coordinate is decoded.
    while index < len(polyline_str):
        # Gather lat/lon changes, store them in a dictionary to apply them later
        for unit in ['latitude', 'longitude']: 
            shift, result = 0, 0

            while True:
                byte = ord(polyline_str[index]) - 63
                index+=1
                result |= (byte & 0x1f) << shift
                shift += 5
                if not byte >= 0x20:
                    break

            if (result & 1):
                changes[unit] = ~(result >> 1)
            else:
                changes[unit] = (result >> 1)

        lat += changes['latitude']
        lng += changes['longitude']

        coordinates.append((lat / 100000.0, lng / 100000.0))

    return coordinates

Answer 2

您可以在Github上查看此回购：Google Maps Polyline Encoding Tool

一个简单的PHP类，用于将折线转换为Google Maps的编码字符串。

Answer 3

<?php

# Do steps 1-11 given here 
# https://developers.google.com/maps/documentation/utilities/polylinealgorithm
# in reverse order and inverted (i.e. left shift -> right shift, add -> subtract)

$string = "udgiEctkwIldeRe}|x@cfmXq|flA`nrvApihC";
# Step 11) unpack the string as unsigned char 'C'
$byte_array = array_merge(unpack('C*', $string));
$results = array();

$index = 0; # tracks which char in $byte_array
do {
  $shift = 0;
  $result = 0;
  do {
    $char = $byte_array[$index] - 63; # Step 10
    # Steps 9-5
    # get the least significat 5 bits from the byte
    # and bitwise-or it into the result
    $result |= ($char & 0x1F) << (5 * $shift);
    $shift++; $index++;
  } while ($char >= 0x20); # Step 8 most significant bit in each six bit chunk
    # is set to 1 if there is a chunk after it and zero if it's the last one
    # so if char is less than 0x20 (0b100000), then it is the last chunk in that num

  # Step 3-5) sign will be stored in least significant bit, if it's one, then 
  # the original value was negated per step 5, so negate again
  if ($result & 1)
    $result = ~$result;
  # Step 4-1) shift off the sign bit by right-shifting and multiply by 1E-5
  $result = ($result >> 1) * 0.00001;
  $results[] = $result;
} while ($index < count($byte_array));

# to save space, lat/lons are deltas from the one that preceded them, so we need to 
# adjust all the lat/lon pairs after the first pair
for ($i = 2; $i < count($results); $i++) {
  $results[$i] += $results[$i - 2];
}

# chunk the array into pairs of lat/lon values
var_dump(array_chunk($results, 2));

# Test correctness by using Google's polylineutility here:
# https://developers.google.com/maps/documentation/utilities/polylineutility

?>

Answer 4

解决此问题的最简单方法..

这是Github Repo的Link，包括用于编码/解码的类。它还有最简单的用法说明。

注意：我必须稍微更改类以解码函数decodeValue中的折线，这是while循环中的最后一行。我有用1000000替换100000

$points[] = array('x' => $lat/1000000, 'y' => $lng/1000000);

如何从PHP中的Google Maps Direction API解码折线

4 个答案:

Python实现