Merge pull request #173 from scottlimmer/fix-167-coordinate-precision

Fix coordinate precision

Author: mstaack

README.md

@@ -233,3 +233,22 @@ Available geometry classes:
  * Polygon
  * MultiPolygon
  * GeometryCollection
+
+## Publishing config
+A configuration file exists for overriding default values. To add to your project, run:
+
+```sh
+php artisan vendor:publish --provider="MStaack\LaravelPostgis\DatabaseServiceProvider" --tag="postgis"
+```
+### Coordinate precision
+The precision of stored/displayed coordinated can be customised in the config.
+
+
+```php
+# config/postgis.php
+return [
+    ...
+    'precision' => 6,
+];
+```
+See http://wiki.gis.com/wiki/index.php/Decimal_degrees#Accuracy for more information

config/postgis.php

@@ -1,5 +1,6 @@
 <?php
 
 return [
-    'schema' => 'public'  // Schema for the Postgis extension
+    'schema' => 'public',  // Schema for the Postgis extension,
+    'precision' => 6, // Control precision of floats in stringifyFloat
 ];

src/Geometries/Point.php

@@ -7,12 +7,26 @@ class Point extends Geometry
     protected $lat;
     protected $lng;
     protected $alt;
+    protected $precision;
 
     public function __construct($lat, $lng, $alt = null)
     {
         $this->lat = (float)$lat;
         $this->lng = (float)$lng;
         $this->alt = isset($alt) ? (float)$alt : null;
+        $this->setPrecision(
+            function_exists('config') ? config('postgis.precision') : 6
+        );
+    }
+
+    public function setPrecision($precision)
+    {
+        $precision = filter_var($precision, FILTER_VALIDATE_INT);
+        if (!is_int($precision)) {
+            throw new \UnexpectedValueException('Precision must be an integer');
+        }
+
+        $this->precision = $precision;
     }
 
     public function getLat()
@@ -52,17 +66,18 @@ public function is3d()
 
     public function toPair()
     {
-        $pair = self::stringifyFloat($this->getLng()) . ' ' . self::stringifyFloat($this->getLat());
+        $pair = $this->stringifyFloat($this->getLng()) . ' ' . $this->stringifyFloat($this->getLat());
         if ($this->is3d()) {
-            $pair .= ' ' . self::stringifyFloat($this->getAlt());
+            $pair .= ' ' . $this->stringifyFloat($this->getAlt());
         }
         return $pair;
     }
 
-    private static function stringifyFloat($float)
+    private function stringifyFloat($float)
     {
         // normalized output among locales
-        return rtrim(rtrim(sprintf('%F', $float), '0'), '.');
+
+        return rtrim(rtrim(sprintf("%.{$this->precision}F", $float), '0'), '.');
     }
 
     public static function fromPair($pair)

tests/Geometries/PointTest.php

@@ -126,4 +126,20 @@ public function testJsonSerialize3d()
         $this->assertInstanceOf(\GeoJson\Geometry\Point::class, $point->jsonSerialize());
         $this->assertSame('{"type":"Point","coordinates":[3.4,1.2,5.6]}', json_encode($point));
     }
+
+    public function testPointPrecisionDefault()
+    {
+        $point = new Point(-37.8745505,144.9102885,12.38);
+
+        $this->assertSame('144.910289 -37.87455 12.38', $point->toPair());
+
+    }
+
+    public function testPointPrecision10()
+    {
+        $point = new Point(-37.87455051578,144.91028850798,7.38257341563);
+        $point->setPrecision(10);
+
+        $this->assertSame('144.910288508 -37.8745505158 7.3825734156', $point->toPair());
+    }
 }