allow intervention to use own drivers

src/Intervention/Image/ImageManager.php

@@ -100,6 +100,7 @@ class ImageManager
      */
     private function createDriver()
     {
+        if (is_string($this->config['driver'])) {
             $drivername = ucfirst($this->config['driver']);
             $driverclass = sprintf('Intervention\\Image\\%s\\Driver', $drivername);
 
@@ -112,6 +113,15 @@ class ImageManager
             );
         }
 
+        if ($this->config['driver'] instanceof AbstractDriver) {
+            return $this->config['driver'];
+        }
+
+        throw new \Intervention\Image\Exception\NotSupportedException(
+            "Unknown driver type."
+        );
+    }
+
     /**
      * Check if all requirements are available
      *

tests/ImageManagerTest.php

@@ -1,5 +1,6 @@
 <?php
 
+use Intervention\Image\Image;
 use Intervention\Image\ImageManager;
 
 class ImageManagerTest extends PHPUnit_Framework_TestCase
@@ -26,4 +27,14 @@ class ImageManagerTest extends PHPUnit_Framework_TestCase
         $this->assertEquals('foo', $manager->config['driver']);
         $this->assertEquals('baz', $manager->config['bar']);
     }
+
+    public function testConfigureObject()
+    {
+        $config = array('driver' => new Intervention\Image\Imagick\Driver());
+        $manager = new ImageManager($config);
+
+        $image = $manager->make('data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7');
+        $this->assertInstanceOf(Image::class, $image);
+        $this->assertInstanceOf(Imagick::class, $image->getCore());
+    }
 }