introduced DownscaleFilterLoader

Imagine/Filter/Loader/DownscaleFilterLoader.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace Liip\ImagineBundle\Imagine\Filter\Loader;
+
+use Imagine\Filter\Basic\Resize;
+use Imagine\Image\ImageInterface;
+use Imagine\Image\Box;
+
+
+/**
+ * downscale filter
+ *
+ */
+class DownscaleFilterLoader implements LoaderInterface
+{
+    /**
+     * {@inheritDoc}
+     */
+    public function load(ImageInterface $image, array $options = array())
+    {
+        if (!isset($options['max'])) {
+            throw new \InvalidArgumentException('Missing max option.');
+        }
+
+        list($width, $height) = $options['max'];
+
+        $size = $image->getSize();
+        $origWidth = $size->getWidth();
+        $origHeight = $size->getHeight();
+
+        if ($origWidth > $width || $origHeight > $height) {
+
+            $widthRatio = $width / $origWidth ;
+            $heightRatio = $height / $origHeight;
+
+            $ratio = $widthRatio > $heightRatio ? $widthRatio : $heightRatio;
+
+            $filter = new Resize(new Box($origWidth * $ratio, $origHeight * $ratio));
+
+            return $filter->apply($image);
+        }
+
+        return $image;
+    }
+}

Resources/config/imagine.xml

@@ -40,6 +40,7 @@
         <parameter key="liip_imagine.filter.loader.strip.class">Liip\ImagineBundle\Imagine\Filter\Loader\StripFilterLoader</parameter>
         <parameter key="liip_imagine.filter.loader.background.class">Liip\ImagineBundle\Imagine\Filter\Loader\BackgroundFilterLoader</parameter>
         <parameter key="liip_imagine.filter.loader.upscale.class">Liip\ImagineBundle\Imagine\Filter\Loader\UpscaleFilterLoader</parameter>
+        <parameter key="liip_imagine.filter.loader.downscale.class">Liip\ImagineBundle\Imagine\Filter\Loader\DownscaleFilterLoader</parameter>
         <parameter key="liip_imagine.filter.loader.auto_rotate.class">Liip\ImagineBundle\Imagine\Filter\Loader\AutoRotateFilterLoader</parameter>
         <parameter key="liip_imagine.filter.loader.rotate.class">Liip\ImagineBundle\Imagine\Filter\Loader\RotateFilterLoader</parameter>
         <parameter key="liip_imagine.filter.loader.interlace.class">Liip\ImagineBundle\Imagine\Filter\Loader\InterlaceFilterLoader</parameter>
@@ -176,6 +177,10 @@
             <tag name="liip_imagine.filter.loader" loader="upscale" />
         </service>
 
+        <service id="liip_imagine.filter.loader.downscale" class="%liip_imagine.filter.loader.downscale.class%">
+            <tag name="liip_imagine.filter.loader" loader="downscale" />
+        </service>
+
         <service id="liip_imagine.filter.loader.auto_rotate" class="%liip_imagine.filter.loader.auto_rotate.class%">
             <tag name="liip_imagine.filter.loader" loader="auto_rotate" />
         </service>

Resources/doc/filters.rst

@@ -78,6 +78,20 @@ on your image. Configuration looks like this:
                 filters:
                     upscale: { min: [800, 600] }
 
+The ``downscale`` filter
+~~~~~~~~~~~~~~~~~~~~~~
+
+The downscale filter, as the name implies, performs a downscale transformation
+on your image. Configuration looks like this:
+
+.. code-block:: yaml
+
+    liip_imagine:
+        filter_sets:
+            my_thumb:
+                filters:
+                    downscale: { max: [1980, 1280] }
+
 The ``crop`` filter
 ~~~~~~~~~~~~~~~~~~~
 

Tests/Functional/Imagine/Filter/Loader/DownscaleFilterLoaderTest.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Liip\ImagineBundle\Tests\Functional\Imagine\Filter\Loader;
+
+use Liip\ImagineBundle\Tests\Functional\WebTestCase;
+
+class DownscaleFilterLoaderTest extends WebTestCase
+{
+    public function testCouldBeGetFromContainerAsService()
+    {
+        $this->createClient();
+        $service = self::$kernel->getContainer()->get('liip_imagine.filter.loader.downscale');
+
+        $this->assertInstanceOf('Liip\ImagineBundle\Imagine\Filter\Loader\DownscaleFilterLoader', $service);
+    }
+}

Tests/Imagine/Filter/Loader/FloatToIntCastByRoundDownscaleFilterLoaderTest.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Liip\ImagineBundle\Tests\Filter;
+
+use Imagine\Gd\Image;
+use Imagine\Gd\Imagine;
+use Liip\ImagineBundle\Imagine\Filter\Loader\DownscaleFilterLoader;
+use Liip\ImagineBundle\Tests\AbstractTest;
+
+/**
+ * @covers Liip\ImagineBundle\Imagine\Filter\Loader\DownscaleFilterLoader
+ *
+ * Due to int casting in Imagine\Image\Box which can lead to wrong pixel
+ * numbers ( e.g. float(201) casted to int(200) ). Solved by round the
+ * floating number before passing to the Box constructor.
+ */
+class FloatToIntCastByRoundDownscaleFilterLoaderTest extends AbstractTest
+{
+    public function testLoad()
+    {
+        $loader = new DownscaleFilterLoader();
+        $imagine = new Imagine();
+        $image = $imagine->open(__DIR__.'/../../../Fixtures/assets/square-300x300.png');
+
+        $options = array(
+            'max' => array(201, 201),
+        );
+
+        $image = $loader->load($image, $options);
+        $size = $image->getSize();
+
+        $this->assertEquals($options['max'], array($size->getWidth(), $size->getHeight()));
+    }
+}