Added LLA2WebMercator conversion

Author: jtejido

src/Geodesy/Conversion/LLA2WebMercator.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace Geodesy\Conversion;
+
+use Geodesy\Location\WebMercator;
+use Geodesy\Location\LatLong;
+use Geodesy\Datum\WGS84;
+
+class LLA2WebMercator extends BaseConversion implements ConversionInterface
+{
+
+	protected $latlong;
+
+	protected $webmercator;
+
+	protected $datum;
+
+    public function __construct(LatLong $latlong)
+    {
+    	parent::__construct();
+        $this->webmercator = new WebMercator;
+        $this->latlong = $latlong;
+        $this->datum = new WGS84; // always set it to WGS84 when converting from LLA to WebMercator
+    }
+
+	public function convert(): WebMercator
+    {
+
+        $lat = deg2rad($this->latlong->getLatitude());
+
+        $long = deg2rad($this->latlong->getLongitude());
+
+        $f = $this->datum->getSemiMajorAxis();
+
+		$sinLat = sin($lat);
+
+        $this->webmercator->setX($this->getUnit()->convert(($f * 0.5) * log((1.0 + $sinLat) / (1.0 - $sinLat))));
+
+        $this->webmercator->setY($this->getUnit()->convert($f * $long));
+
+        return $this->webmercator;
+
+    }
+
+
+}

src/Geodesy/Conversion/WebMercator2LLA.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace Geodesy\Conversion;
+
+use Geodesy\Location\WebMercator;
+use Geodesy\Location\LatLong;
+use Geodesy\Datum\WGS84;
+
+class WebMercator2LLA extends BaseConversion implements ConversionInterface
+{
+
+	protected $latlong;
+
+	protected $webmercator;
+
+	protected $datum;
+
+    public function __construct(WebMercator $webmercator)
+    {
+    	parent::__construct();
+        $this->webmercator = $webmercator;
+        $this->latlong = new LatLong;
+        $this->datum = $this->webmercator->getReference();
+    }
+
+	public function convert(): LatLong
+    {
+
+        $x = $this->webmercator->getX();
+        $y = $this->webmercator->getY();
+
+        $f = $this->datum->getSemiMajorAxis();
+
+        $lat = $x / $f;
+
+		$long = (pi() / 2) - (2 * atan(exp(-1.0 * $y / $f)));
+
+        $this->latlong->setReference($this->datum);
+
+        $this->latlong->setLatitude(rad2deg($lat));
+
+        $this->latlong->setLongitude(rad2deg($long));
+
+        return $this->latlong;
+
+    }
+
+
+}

src/Geodesy/Location/WebMercator.php

@@ -0,0 +1,59 @@
+<?php
+
+namespace Geodesy\Location;
+
+use Geodesy\Datum\WGS84;
+use Geodesy\Datum\DatumInterface;
+
+class WebMercator
+{
+    /**
+     * Web Mercator, Google Web Mercator, Spherical Mercator, WGS 84 Web Mercator[1] or WGS 84/Pseudo-Mercator is a variant of the Mercator 
+     * projection and is the de facto standard for Web mapping applications.
+     * X is easting and Y is northing.
+     */
+	private $x;
+
+    private $y;
+
+    private $referenceDatum;
+
+    public function __construct()
+    {
+        $this->x = null;
+        $this->y = null;
+        $this->referenceDatum = new WGS84;
+    }
+
+    public function getReference(): WGS84
+    {
+        return $this->referenceDatum;
+    }
+
+    public function setX(float $x)
+    {
+        $this->x = $x;
+    }
+
+    public function setY(float $y)
+    {
+        $this->y = $y;
+    }
+
+    public function getX(): float
+    {
+        if($this->x === null) {
+        	throw new \Exception('X is not set.');
+        }
+        return $this->x;
+    }
+
+    public function getY(): float
+    {
+        if($this->y === null) {
+        	throw new \Exception('Y is not set.');
+        }
+        return $this->y;
+    }
+
+}