Add background color parameter to CropModifier

src/Drivers/Gd/Modifiers/CropModifier.php

@@ -2,8 +2,12 @@
 
 namespace Intervention\Image\Drivers\Gd\Modifiers;
 
+use Intervention\Image\Colors\Rgb\Channels\Blue;
+use Intervention\Image\Colors\Rgb\Channels\Green;
+use Intervention\Image\Colors\Rgb\Channels\Red;
 use Intervention\Image\Drivers\Gd\Cloner;
 use Intervention\Image\Drivers\Gd\SpecializedModifier;
+use Intervention\Image\Interfaces\ColorInterface;
 use Intervention\Image\Interfaces\FrameInterface;
 use Intervention\Image\Interfaces\ImageInterface;
 use Intervention\Image\Interfaces\SizeInterface;
@@ -12,6 +16,7 @@ use Intervention\Image\Interfaces\SizeInterface;
  * @method SizeInterface crop(ImageInterface $image)
  * @property int $offset_x
  * @property int $offset_y
+ * @property mixed $background
  */
 class CropModifier extends SpecializedModifier
 {
@@ -19,18 +24,23 @@ class CropModifier extends SpecializedModifier
     {
         $originalSize = $image->size();
         $crop = $this->crop($image);
+        $background = $this->driver()->handleInput($this->background);
 
         foreach ($image as $frame) {
-            $this->cropFrame($frame, $originalSize, $crop);
+            $this->cropFrame($frame, $originalSize, $crop, $background);
         }
 
         return $image;
     }
 
-    protected function cropFrame(FrameInterface $frame, SizeInterface $originalSize, SizeInterface $resizeTo): void
-    {
+    protected function cropFrame(
+        FrameInterface $frame,
+        SizeInterface $originalSize,
+        SizeInterface $resizeTo,
+        ColorInterface $background
+    ): void {
         // create new image
-        $modified = Cloner::cloneEmpty($frame->native(), $resizeTo);
+        $modified = Cloner::cloneEmpty($frame->native(), $resizeTo, $background);
 
         // define offset
         $offset_x = ($resizeTo->pivot()->x() + $this->offset_x);
@@ -42,6 +52,27 @@ class CropModifier extends SpecializedModifier
         $targetWidth = $targetWidth < $originalSize->width() ? $targetWidth + $offset_x : $targetWidth;
         $targetHeight = $targetHeight < $originalSize->height() ? $targetHeight + $offset_y : $targetHeight;
 
+        // make image area transparent to keep transparency
+        // even if background-color is set
+        $transparent = imagecolorallocatealpha(
+            $modified,
+            $background->channel(Red::class)->value(),
+            $background->channel(Green::class)->value(),
+            $background->channel(Blue::class)->value(),
+            127,
+        );
+
+        imagealphablending($modified, false); // do not blend / just overwrite
+        // imagecolortransparent($modified, $transparent);
+        imagefilledrectangle(
+            $modified,
+            $offset_x * -1,
+            $offset_y * -1,
+            $targetWidth,
+            $targetHeight,
+            $transparent
+        );
+
         // copy content from resource
         imagecopyresampled(
             $modified,
@@ -56,6 +87,8 @@ class CropModifier extends SpecializedModifier
             $targetHeight
         );
 
+        imagealphablending($modified, true);
+
         // set new content as recource
         $frame->setNative($modified);
     }

src/Drivers/Imagick/Modifiers/CropModifier.php

@@ -2,6 +2,7 @@
 
 namespace Intervention\Image\Drivers\Imagick\Modifiers;
 
+use ImagickDraw;
 use Intervention\Image\Drivers\DriverSpecializedModifier;
 use Intervention\Image\Interfaces\ImageInterface;
 use Intervention\Image\Interfaces\SizeInterface;
@@ -10,20 +11,73 @@ use Intervention\Image\Interfaces\SizeInterface;
  * @method SizeInterface crop(ImageInterface $image)
  * @property int $offset_x
  * @property int $offset_y
+ * @property mixed $background
  */
 class CropModifier extends DriverSpecializedModifier
 {
     public function apply(ImageInterface $image): ImageInterface
     {
+        $originalSize = $image->size();
         $crop = $this->crop($image);
+        $background = $this->driver()->colorProcessor($image->colorspace())->colorToNative(
+            $this->driver()->handleInput($this->background)
+        );
+
+        $draw = new ImagickDraw();
+        $draw->setFillColor($background);
 
         foreach ($image as $frame) {
+            // crop image
             $frame->native()->extentImage(
                 $crop->width(),
                 $crop->height(),
                 $crop->pivot()->x() + $this->offset_x,
                 $crop->pivot()->y() + $this->offset_y
             );
+
+            // cover the possible newly created areas with background color
+            if ($crop->width() > $originalSize->width()) {
+                $draw->rectangle(
+                    $originalSize->width() + ($this->offset_x * -1),
+                    0,
+                    $crop->width(),
+                    $crop->height()
+                );
+                $frame->native()->drawImage($draw);
+            }
+
+            // cover the possible newly created areas with background color
+            if ($crop->height() > $originalSize->height()) {
+                $draw->rectangle(
+                    0,
+                    $originalSize->height() + ($this->offset_y * -1),
+                    $crop->width(),
+                    $crop->height()
+                );
+                $frame->native()->drawImage($draw);
+            }
+
+            // cover the possible newly created areas with background color
+            if ($this->offset_x < 0) {
+                $draw->rectangle(
+                    0,
+                    0,
+                    ($this->offset_x * -1) - 1,
+                    $originalSize->height() + ($this->offset_y * -1)
+                );
+                $frame->native()->drawImage($draw);
+            }
+
+            // cover the possible newly created areas with background color
+            if ($this->offset_y < 0) {
+                $draw->rectangle(
+                    0,
+                    0,
+                    $crop->width(),
+                    ($this->offset_y * -1) - 1,
+                );
+                $frame->native()->drawImage($draw);
+            }
         }
 
         return $image;

src/Image.php

@@ -715,9 +715,10 @@ final class Image implements ImageInterface
         int $height,
         int $offset_x = 0,
         int $offset_y = 0,
+        mixed $background = 'ffffff',
         string $position = 'top-left'
     ): ImageInterface {
-        return $this->modify(new CropModifier($width, $height, $offset_x, $offset_y, $position));
+        return $this->modify(new CropModifier($width, $height, $offset_x, $offset_y, $background, $position));
     }
 
     /**

src/Interfaces/ImageInterface.php

@@ -491,6 +491,7 @@ interface ImageInterface extends IteratorAggregate, Countable
      * @param int $height
      * @param int $offset_x
      * @param int $offset_y
+     * @param mixed $background
      * @param string $position
      * @return ImageInterface
      */
@@ -499,6 +500,7 @@ interface ImageInterface extends IteratorAggregate, Countable
         int $height,
         int $offset_x = 0,
         int $offset_y = 0,
+        mixed $background = 'ffffff',
         string $position = 'top-left'
     ): ImageInterface;
 

src/Modifiers/CropModifier.php

@@ -13,6 +13,7 @@ class CropModifier extends AbstractModifier
         public int $height,
         public int $offset_x = 0,
         public int $offset_y = 0,
+        public mixed $background = 'f00',
         public string $position = 'top-left'
     ) {
     }

tests/Drivers/Gd/Modifiers/CropModifierTest.php

@@ -17,11 +17,23 @@ class CropModifierTest extends TestCase
     public function testModify(): void
     {
         $image = $this->readTestImage('blocks.png');
-        $image = $image->modify(new CropModifier(200, 200, 0, 0, 'bottom-right'));
+        $image = $image->modify(new CropModifier(200, 200, 0, 0, 'ffffff', 'bottom-right'));
         $this->assertEquals(200, $image->width());
         $this->assertEquals(200, $image->height());
         $this->assertColor(255, 0, 0, 255, $image->pickColor(5, 5));
         $this->assertColor(255, 0, 0, 255, $image->pickColor(100, 100));
         $this->assertColor(255, 0, 0, 255, $image->pickColor(190, 190));
     }
+
+    public function testModifyExtend(): void
+    {
+        $image = $this->readTestImage('blocks.png');
+        $image = $image->modify(new CropModifier(800, 100, -10, -10, 'ff0000', 'top-left'));
+        $this->assertEquals(800, $image->width());
+        $this->assertEquals(100, $image->height());
+        $this->assertColor(255, 0, 0, 255, $image->pickColor(9, 9));
+        $this->assertColor(0, 0, 255, 255, $image->pickColor(16, 16));
+        $this->assertColor(0, 0, 255, 255, $image->pickColor(445, 16));
+        $this->assertTransparency($image->pickColor(460, 16));
+    }
 }

tests/Drivers/Imagick/Modifiers/CropModifierTest.php

@@ -17,11 +17,23 @@ class CropModifierTest extends TestCase
     public function testModify(): void
     {
         $image = $this->readTestImage('blocks.png');
-        $image = $image->modify(new CropModifier(200, 200, 0, 0, 'bottom-right'));
+        $image = $image->modify(new CropModifier(200, 200, 0, 0, 'ffffff', 'bottom-right'));
         $this->assertEquals(200, $image->width());
         $this->assertEquals(200, $image->height());
         $this->assertColor(255, 0, 0, 255, $image->pickColor(5, 5));
         $this->assertColor(255, 0, 0, 255, $image->pickColor(100, 100));
         $this->assertColor(255, 0, 0, 255, $image->pickColor(190, 190));
     }
+
+    public function testModifyExtend(): void
+    {
+        $image = $this->readTestImage('blocks.png');
+        $image = $image->modify(new CropModifier(800, 100, -10, -10, 'ff0000', 'top-left'));
+        $this->assertEquals(800, $image->width());
+        $this->assertEquals(100, $image->height());
+        $this->assertColor(255, 0, 0, 255, $image->pickColor(9, 9));
+        $this->assertColor(0, 0, 255, 255, $image->pickColor(16, 16));
+        $this->assertColor(0, 0, 255, 255, $image->pickColor(445, 16));
+        $this->assertTransparency($image->pickColor(460, 16));
+    }
 }