如何从PHP中的Google Maps Direction API解码折线

Question

我从以下URL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@ ˚F@ @@ 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?@BF？vC？hB？@BpM？@？j @@ p @@ | KB~Q @ pFBbHBvF @ z @？f @@ jB？nA @ z @ DzD @ VJ ~CLfC\| E？B？@ HnANtAVpDRpCLbB ^ dFTxC @ LZvDF ^ HrALlCH EB|H?DBpEB~V?^BhDJR？@@ \？~A？nABrL？@？jD @ vD @ vA？h @？BLx [？x @？B？\？F @ pA？h @ D~H？@ Bz @ Dr @ RbCLfA\rBPv @@@ T~ @ t @ bCPf @ z @ xBd @ rAf @ dB\zAN~ @ PjAT~BFrADxAH X?z@?@HfW?x@?F?@@dD@^F|Y@v@D|JBzH?rB@tAApABxB?bA@dBBxABlAJ~CJrBDfANhBNjCLlCLpBHlBFnB@C？| A？v @ AlBCdA？r @EjEC | BItEMdGEtAIfEI | BKzDOzGEjCCl @？@ MnDW HSrFSlFAd@?@qA|[Ct@Cj@At@AbA?hBAdBClBQjFQnECr@EAYjFIzAWxDQpCYpEAFItACt @ S~C] | GSlEMnCMtCGdAKlBQxDg @ bLAT？BKrCAn @ Ad @？x @？p @？J？| @@ lA @ z @ BbABn @ Bt @@ @HnAPxB@LB^LAT BPAP~ @ Z~ALn @？@@ Fd @ | BjAfGd @ dDd @ | D\bFDf @ D~ @@ f @ B | @@ xCJ P?dBBEDtE @ bADlAR EJlABh@Dp@F@ @xEJdBHlCF~C@nA?@?@DfG?ADhLBbD @ x @？F @ ~C？dCNbTDrIBxDLbO @~AV Y?@DfHEvDGlC]fHGhD?lHPlP?@?B?R?@BfBNbRBpENfQDrGBvCDrEBtEBzABfABx@B~@^FHx @ H | @ @bDPxAZpCTbDNDBlC @ j @@ j @ BhAHhLBvC？p @ BlB？jAAfAAx @ C @MzDM|B_@tDq@pF]fB]zAo@fCc@~Am@jBo@dBoCxG?@?@Sd@g@vAY~@St@W|@_@bBUhA_@zBWhBKAOpAKfAEp @ Gz @ Cb @ GpACZAVAh @ Ad @ AX？f @ At @ 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,但是如果您要从Google地图解码折线字符串,则此线程接近搜索结果的顶部.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; 更多信息在我的repo页面上找到.

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编码工具

一个简单的PHP类,用于将折线转换为Google Maps的编码字符串.