imageflip function added for PHP < 5.5

Author: adityapatadia

lib/ImageResize.php

@@ -523,3 +523,50 @@ protected function getCropPosition($expectedSize, $position = self::CROPCENTER)
         return $size;
     }
 }
+
+// imageflip definition for PHP < 5.5
+if (!function_exists('imageflip')) {
+  define('IMG_FLIP_HORIZONTAL', 0);
+  define('IMG_FLIP_VERTICAL', 1);
+  define('IMG_FLIP_BOTH', 2);
+
+  function imageflip($image, $mode) {
+    switch ($mode) {
+      case IMG_FLIP_HORIZONTAL: {
+        $max_x = imagesx($image) - 1;
+        $half_x = $max_x / 2;
+        $sy = imagesy($image);
+        $temp_image = imageistruecolor($image)? imagecreatetruecolor(1, $sy): imagecreate(1, $sy);
+        for ($x = 0; $x < $half_x; ++$x) {
+          imagecopy($temp_image, $image, 0, 0, $x, 0, 1, $sy);
+          imagecopy($image, $image, $x, 0, $max_x - $x, 0, 1, $sy);
+          imagecopy($image, $temp_image, $max_x - $x, 0, 0, 0, 1, $sy);
+        }
+        break;
+      }
+      case IMG_FLIP_VERTICAL: {
+        $sx = imagesx($image);
+        $max_y = imagesy($image) - 1;
+        $half_y = $max_y / 2;
+        $temp_image = imageistruecolor($image)? imagecreatetruecolor($sx, 1): imagecreate($sx, 1);
+        for ($y = 0; $y < $half_y; ++$y) {
+          imagecopy($temp_image, $image, 0, 0, 0, $y, $sx, 1);
+          imagecopy($image, $image, 0, $y, 0, $max_y - $y, $sx, 1);
+          imagecopy($image, $temp_image, 0, $max_y - $y, 0, 0, $sx, 1);
+        }
+        break;
+      }
+      case IMG_FLIP_BOTH: {
+        $sx = imagesx($image);
+        $sy = imagesy($image);
+        $temp_image = imagerotate($image, 180, 0);
+        imagecopy($image, $temp_image, 0, 0, 0, 0, $sx, $sy);
+        break;
+      }
+      default: {
+        return;
+      }
+    }
+    imagedestroy($temp_image);
+  }
+}