commit version 22.12.12447

includes/weathermap/lib/geometry.php

@@ -0,0 +1,55 @@
+<?php
+
+function getTriangleArea($point1, $point2, $point3)
+{
+    $area = abs($point1->x * ($point2->y - $point3->y)
+        + $point2->x * ($point3->y - $point1->y)
+        + $point3->x * ($point1->y - $point2->y)) / 2.0;
+
+    return $area;
+}
+
+class WMLineSegment
+{
+    public $point1;
+    public $point2;
+    public $vector;
+
+    public function __construct($p1, $p2)
+    {
+        $this->point1 = $p1;
+        $this->point2 = $p2;
+
+        $this->vector = $p1->vectorToPoint($p2);
+    }
+
+    public function __toString()
+    {
+        return sprintf("{%s--%s}", $this->point1, $this->point2);
+    }
+}
+
+/**
+ * rotate a list of points around cx,cy by an angle in radians, IN PLACE
+ *
+ * TODO: This should be using WMPoints! (And should be a method of WMPoint)
+ *
+ * @param $points array of ordinates (x,y,x,y,x,y...)
+ * @param $centre_x centre of rotation, X coordinate
+ * @param $centre_y centre of rotation, Y coordinate
+ * @param int $angle angle in radians
+ */
+function rotateAboutPoint(&$points, $centre_x, $centre_y, $angle = 0)
+{
+    $nPoints = count($points) / 2;
+
+    for ($i = 0; $i < $nPoints; $i ++) {
+        $delta_x = $points[$i * 2] - $centre_x;
+        $delta_y = $points[$i * 2 + 1] - $centre_y;
+        $rotated_x = $delta_x * cos($angle) - $delta_y * sin($angle);
+        $rotated_y = $delta_y * cos($angle) + $delta_x * sin($angle);
+
+        $points[$i * 2] = $rotated_x + $centre_x;
+        $points[$i * 2 + 1] = $rotated_y + $centre_y;
+    }
+}