fix minor bug for extending bounding boxes

Releases v0.3.1

Author: laufhannes

composer.json

@@ -1,7 +1,7 @@
 {
   "name": "runalyze/static-maps",
   "description": "Library to create static images from various map tile providers.",
-  "version": "0.1.1",
+  "version": "0.3.1",
   "license": "MIT",
   "require": {
     "php": ">=7.0",

src/Feature/Route.php

@@ -156,17 +156,13 @@ public function getBoundingBox(float $paddingInPercent = 0.0, float $paddingRigh
             }
         }
 
-        if (0.0 < max($paddingTop, $paddingRight, $paddingBottom, $paddingLeft)) {
-            $deltaLatitude = $maxLatitude - $minLatitude;
-            $deltaLongitude = $maxLongitude - $minLongitude;
+        $boundingBox = new BoundingBox($minLatitude, $maxLatitude, $minLongitude, $maxLongitude);
 
-            $minLatitude -= $deltaLatitude * $paddingBottom / 100.0;
-            $maxLatitude += $deltaLatitude * $paddingTop / 100.0;
-            $minLongitude -= $deltaLongitude * $paddingLeft / 100.0;
-            $maxLongitude += $deltaLongitude * $paddingRight / 100.0;
+        if (0.0 < max($paddingTop, $paddingRight, $paddingBottom, $paddingLeft)) {
+            return $boundingBox->extendBy($paddingTop, $paddingRight, $paddingBottom, $paddingLeft);
         }
 
-        return new BoundingBox($minLatitude, $maxLatitude, $minLongitude, $maxLongitude);
+        return $boundingBox;
     }
 
     public function isEmpty(): bool

src/Tests/Feature/RouteTest.php

@@ -45,16 +45,16 @@ public function testBoundingBoxWithPadding()
         ]);
 
         $this->assertFalse($route->isEmpty());
-        $this->assertThatBoundingBoxIsEqual(new BoundingBox(50.0, 51.0, 10.0, 10.1), $route->getBoundingBox());
-        $this->assertThatBoundingBoxIsEqual(new BoundingBox(49.9, 51.1, 9.99, 10.11), $route->getBoundingBox(10.0));
-        $this->assertThatBoundingBoxIsEqual(new BoundingBox(50.0, 51.1, 9.95, 10.1), $route->getBoundingBox(10.0, 0.0, 0.0, 50.0));
+        $this->assertThatBoundingBoxIsEqual(new BoundingBox(50.000, 51.000, 10.000, 10.100), $route->getBoundingBox());
+        $this->assertThatBoundingBoxIsEqual(new BoundingBox(49.888, 51.110, 9.989, 10.111), $route->getBoundingBox(10.0));
+        $this->assertThatBoundingBoxIsEqual(new BoundingBox(50.000, 51.110, 9.900, 10.100), $route->getBoundingBox(10.0, 0.0, 0.0, 50.0));
     }
 
     protected function assertThatBoundingBoxIsEqual(BoundingBoxInterface $expected, BoundingBoxInterface $actual)
     {
-        $this->assertEquals($expected->getMinLatitude(), $actual->getMinLatitude());
-        $this->assertEquals($expected->getMaxLatitude(), $actual->getMaxLatitude());
-        $this->assertEquals($expected->getMinLongitude(), $actual->getMinLongitude());
-        $this->assertEquals($expected->getMaxLongitude(), $actual->getMaxLongitude());
+        $this->assertEquals($expected->getMinLatitude(), $actual->getMinLatitude(), '', 0.001);
+        $this->assertEquals($expected->getMaxLatitude(), $actual->getMaxLatitude(), '', 0.001);
+        $this->assertEquals($expected->getMinLongitude(), $actual->getMinLongitude(), '', 0.001);
+        $this->assertEquals($expected->getMaxLongitude(), $actual->getMaxLongitude(), '', 0.001);
     }
 }

src/Tests/Viewport/BoundingBoxTest.php

@@ -23,10 +23,7 @@ public function testCenterCoordinates(float $minLatitude, float $minLongitude, f
     {
         $boundingBox = new BoundingBox($minLatitude, $maxLatitude, $minLongitude, $maxLongitude);
 
-        $this->assertEquals($minLatitude, $boundingBox->getMinLatitude());
-        $this->assertEquals($maxLatitude, $boundingBox->getMaxLatitude());
-        $this->assertEquals($minLongitude, $boundingBox->getMinLongitude());
-        $this->assertEquals($maxLongitude, $boundingBox->getMaxLongitude());
+        $this->assertThatBoundingBoxEquals([$minLatitude, $maxLatitude, $minLongitude, $maxLongitude], $boundingBox);
         $this->assertEquals($expectedCenterLatitude, $boundingBox->getCenterLatitude());
         $this->assertEquals($expectedCenterLongitude, $boundingBox->getCenterLongitude());
     }
@@ -40,4 +37,21 @@ public function getProviderForCenterCoordinates()
             [15.0, -160.0, 19.0, -60.0, 17.0, -110.0]
         ];
     }
+
+    public function testExtendByZero()
+    {
+        $boundingBox = new BoundingBox(49.6, 7.6, 49.7, 7.7);
+
+        $this->assertThatBoundingBoxEquals([49.6, 7.6, 49.7, 7.7], $boundingBox);
+        $this->assertThatBoundingBoxEquals([49.6, 7.6, 49.7, 7.7], $boundingBox->extendBy(0.0));
+        $this->assertThatBoundingBoxEquals([49.6, 7.6, 49.7, 7.7], $boundingBox->extendBy(0.0, 0.0, 0.0, 0.0));
+    }
+
+    protected function assertThatBoundingBoxEquals(array $expectedBoundaries, BoundingBox $boundingBox)
+    {
+        $this->assertEquals($expectedBoundaries[0], $boundingBox->getMinLatitude());
+        $this->assertEquals($expectedBoundaries[1], $boundingBox->getMaxLatitude());
+        $this->assertEquals($expectedBoundaries[2], $boundingBox->getMinLongitude());
+        $this->assertEquals($expectedBoundaries[3], $boundingBox->getMaxLongitude());
+    }
 }

src/Viewport/BoundingBox.php

@@ -74,4 +74,36 @@ public function getCenterLongitude(): float
 
         return $center;
     }
+
+    public function extendBy(float $paddingInPercent = 0.0, float $paddingRight = null, float $paddingBottom = null, float $paddingLeft = null): BoundingBoxInterface
+    {
+        $paddingTop = $paddingInPercent / (100.0 - $paddingInPercent);
+        $paddingRight = null === $paddingRight ? $paddingTop : $paddingRight / (100.0 - $paddingRight);
+        $paddingBottom = null === $paddingBottom ? $paddingTop : $paddingBottom / (100.0 - $paddingBottom);
+        $paddingLeft = null === $paddingLeft ? $paddingTop : $paddingLeft / (100.0 - $paddingLeft);
+
+        $deltaLatitudeY = ($this->projectLatitudeToY($this->MaxLatitude) - $this->projectLatitudeToY($this->MinLatitude));
+        $deltaLongitude = $this->MaxLongitude - $this->MinLongitude;
+
+        $this->MinLatitude = $this->projectYToLatitude($this->projectLatitudeToY($this->MinLatitude) - $deltaLatitudeY * $paddingBottom);
+        $this->MaxLatitude = $this->projectYToLatitude($this->projectLatitudeToY($this->MaxLatitude) + $deltaLatitudeY * $paddingTop);
+        $this->MinLongitude -= $deltaLongitude * $paddingLeft;
+        $this->MaxLongitude += $deltaLongitude * $paddingRight;
+
+        return $this;
+    }
+
+    private function projectLatitudeToY(float $latitude): float
+    {
+        $zoom = 10;
+
+        return (1.0 - log(tan($latitude * pi() / 180.0) + 1.0 / cos($latitude * pi() / 180.0)) / pi()) / 2.0 * pow(2.0, $zoom);
+    }
+
+    private function projectYToLatitude(float $y): float
+    {
+        $zoom = 10;
+
+        return atan(sinh(pi() * (1.0 - 2.0 * $y / pow(2.0, $zoom)))) * 180.0 / pi();
+    }
 }

src/Viewport/BoundingBoxInterface.php

@@ -28,4 +28,6 @@ public function getMaxLongitude(): float;
     public function getCenterLatitude(): float;
 
     public function getCenterLongitude(): float;
+
+    public function extendBy(float $paddingInPercent = 0.0, float $paddingRight = null, float $paddingBottom = null, float $paddingLeft = null): self;
 }