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File: GlobalMapTiles.php

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  Classes of Chi Hoang  >  Hilbert curve  >  GlobalMapTiles.php  >  Download  
File: GlobalMapTiles.php
Role: Auxiliary script
Content type: text/plain
Description: Mercantor projection of geo coordinates
Class: Hilbert curve
Generate points of an Hilbert curve
Author: By
Last change:
Date: 4 years ago
Size: 6,579 bytes
 

Contents

Class file image Download
<?php
/*
    GlobalMapTiles - part of Aggregate Map Tools
    Version 1.0
    Copyright (c) 2009 The Bivings Group
    All rights reserved.
    Author: John Bafford
   
    http://www.bivings.com/
    http://bafford.com/softare/aggregate-map-tools/
   
    Based on GDAL2Tiles / globalmaptiles.py
    Original python version Copyright (c) 2008 Klokan Petr Pridal. All rights reserved.
    http://www.klokan.cz/projects/gdal2tiles/
   
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
    to deal in the Software without restriction, including without limitation
    the rights to use, copy, modify, merge, publish, distribute, sublicense,
    and/or sell copies of the Software, and to permit persons to whom the
    Software is furnished to do so, subject to the following conditions:
   
    The above copyright notice and this permission notice shall be included
    in all copies or substantial portions of the Software.
   
    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    DEALINGS IN THE SOFTWARE.
*/

class GlobalMercator
{
    var
$tileSize;
    var
$initialResolution;
    var
$originShift;
   
   
//Initialize the TMS Global Mercator pyramid
   
function __construct($tileSize = 256)
    {
       
$this->tileSize = $tileSize;
       
$this->initialResolution = 2 * M_PI * 6378137 / $this->tileSize;
       
# 156543.03392804062 for tileSize 256 Pixels
       
$this->originShift = 2 * M_PI * 6378137 / 2.0;
       
# 20037508.342789244
   
}
   
   
//Converts given lat/lon in WGS84 Datum to XY in Spherical Mercator EPSG:900913
   
function LatLonToMeters($lat, $lon)
    {
       
$mx = $lon * $this->originShift / 180.0;
       
$my = log( tan((90 + $lat) * M_PI / 360.0 )) / (M_PI / 180.0);
   
       
$my *= $this->originShift / 180.0;
       
        return array(
$mx, $my);
    }
   
   
//Converts XY point from Spherical Mercator EPSG:900913 to lat/lon in WGS84 Datum
   
function MetersToLatLon($mx, $my)
    {
       
$lon = ($mx / $this->originShift) * 180.0;
       
$lat = ($my / $this->originShift) * 180.0;
   
       
$lat = 180 / M_PI * (2 * atan( exp( $lat * M_PI / 180.0)) - M_PI / 2.0);
       
        return array(
$lat, $lon);
    }
   
   
//Converts pixel coordinates in given zoom level of pyramid to EPSG:900913
   
function PixelsToMeters($px, $py, $zoom)
    {
       
$res = $this->Resolution($zoom);
       
$mx = $px * $res - $this->originShift;
       
$my = $py * $res - $this->originShift;
       
        return array(
$mx, $my);
    }
   
   
//Converts EPSG:900913 to pyramid pixel coordinates in given zoom level
   
function MetersToPixels($mx, $my, $zoom)
    {
       
$res = $this->Resolution( $zoom );
       
       
$px = ($mx + $this->originShift) / $res;
       
$py = ($my + $this->originShift) / $res;
       
        return array(
$px, $py);
    }

   
//Returns a tile covering region in given pixel coordinates
   
function PixelsToTile($px, $py)
    {
       
$tx = ceil( $px / $this->tileSize ) - 1;
       
$ty = ceil( $py / $this->tileSize ) - 1;
       
        return array(
$tx, $ty);
    }
   
   
//Returns tile for given mercator coordinates
   
function MetersToTile($mx, $my, $zoom)
    {
        list(
$px, $py) = $this->MetersToPixels($mx, $my, $zoom);
       
        return
$this->PixelsToTile($px, $py);
    }
   
   
//Returns bounds of the given tile in EPSG:900913 coordinates
   
function TileBounds($tx, $ty, $zoom)
    {
        list(
$minx, $miny) = $this->PixelsToMeters( $tx*$this->tileSize, $ty*$this->tileSize, $zoom );
        list(
$maxx, $maxy) = $this->PixelsToMeters( ($tx+1)*$this->tileSize, ($ty+1)*$this->tileSize, $zoom );
       
        return array(
$minx, $miny, $maxx, $maxy);
    }
   
   
//Returns bounds of the given tile in latutude/longitude using WGS84 datum
   
function TileLatLonBounds($tx, $ty, $zoom)
    {
       
$bounds = $this->TileBounds($tx, $ty, $zoom);
       
        list(
$minLat, $minLon) = $this->MetersToLatLon($bounds[0], $bounds[1]);
        list(
$maxLat, $maxLon) = $this->MetersToLatLon($bounds[2], $bounds[3]);
        
        return array(
$minLat, $minLon, $maxLat, $maxLon);
    }
   
   
//Resolution (meters/pixel) for given zoom level (measured at Equator)
   
function Resolution($zoom)
    {
        return
$this->initialResolution / (1 << $zoom);
    }
   
   
//Converts TMS tile coordinates to Microsoft QuadTree
   
function QuadTree($tx, $ty, $zoom)
    {
       
$quadKey = '';
       
       
$ty = ((1 << $zoom) - 1) - $ty;
        foreach(
range($zoom, 1, -1) as $i)
        {
           
$digit = 0;
           
           
$mask = 1 << ($i-1);
           
            if((
$tx & $mask) != 0)
               
$digit += 1;
           
            if((
$ty & $mask) != 0)
               
$digit += 2;
           
           
$quadKey .= $digit;
        }
       
        return
$quadKey;
    }
   
   
//Converts a quadkey to tile coordinates
   
function QuadTreeToTile($quadtree, $zoom)
    {
       
$tx = 0;
       
$ty = 0;
       
        for(
$i = $zoom; $i >= 1; $i--)
        {
           
$ch = $quadtree[$zoom - $i];
           
$mask = 1 << ($i-1);
           
           
$digit = $ch - '0';
           
            if(
$digit & 1)
               
$tx += $mask;
           
            if(
$digit & 2)
               
$ty += $mask;
        }
       
       
$ty = ((1 << $zoom) - 1) - $ty;
       
        return array(
$tx, $ty);
    }
   
   
//Converts a latitude and longitude to quadtree at the specified zoom level
   
function LatLonToQuadTree($lat, $lon, $zoom)
    {
        list(
$mx, $my) = $this->LatLonToMeters($lat, $lon);
        list(
$tx, $ty) = $this->MetersToTile($mx, $my, $zoom);
       
        return
$this->QuadTree($tx, $ty, $zoom);
    }
   
   
//Converts a quadtree location into a latitude/longitude bounding rectangle
   
function QuadTreeToLatLon($quadtree)
    {
       
$zoom = strlen($quadtree);
       
        list(
$tx, $ty) = $this->QuadTreeToTile($quadtree, $zoom);
        return
$this->TileLatLonBounds($tx, $ty, $zoom);
    }
   
   
//Returns a list of all of the quadtree locations at a given zoom level within a latitude/longude box
   
function GetQuadTreeList($zoom, array $latLon, array $latLonMax = array())
    {
        list(
$lat, $lon) = $latLon;
       
        if(
$latLonMax)
        {
            list(
$latMax, $lonMax) = $latLonMax;
           
            if(
$latMax < $lat || $lonMax < $lon)
                return
false;
        }
       
        list(
$mx, $my) = $this->LatLonToMeters($lat, $lon);
        list(
$tminx, $tminy) = $this->MetersToTile($mx, $my, $zoom);
       
        if(
$latLonMax)
        {
            list(
$mx, $my) = $this->LatLonToMeters($latMax, $lonMax);
            list(
$tmaxx, $tmaxy) = $this->MetersToTile($mx, $my, $zoom);
        }
        else
        {
           
$tmaxx = $tminx;
           
$tmaxy = $tminy;
        }
       
       
$arr = array();
        foreach(
range($tminy, $tmaxy) as $ty)
            foreach(
range($tminx, $tmaxx) as $tx)
            {
               
$quadtree = $this->QuadTree($tx, $ty, $zoom);
               
               
$arr[$quadtree] = $this->TileLatLonBounds($tx, $ty, $zoom);
            }
       
        return
$arr;
    }
}
?>