feat: add support for background image URL

src/Image.php

@@ -11,6 +11,7 @@ class Image
 
     protected string $accentColor;
     protected ?Background $background = null;
+    protected ?string $backgroundURL = null;
     protected string $backgroundColor = '#ffffff';
     protected float $backgroundOpacity = 1.0;
     protected ?Border $border = null;
@@ -73,6 +74,22 @@ public function background(Background $background, float $opacity = 1.0): self
         return $this;
     }
 
+    public function backgroundURL(string $backgroundURL, float $opacity = 1.0): self
+    {
+        if (!filter_var($backgroundURL, FILTER_VALIDATE_URL)) {
+            throw new \InvalidArgumentException('URL is not valid');
+        }
+
+        $imageInfo = @getimagesize($backgroundURL);
+        if (!$imageInfo) {
+            throw new \InvalidArgumentException('URL doesn\'t point to an image');
+        }
+
+        $this->backgroundOpacity = $opacity < 0 ? 0 : ($opacity > 1 ? 1 : $opacity);
+        $this->backgroundURL = $backgroundURL;
+        return $this;
+    }
+
     public function callToAction(string $content): self
     {
         $this->callToAction = $content;

src/Traits/RendersImages.php

@@ -178,4 +178,45 @@ protected function renderBackground(): void
             $filledRows++;
         }
     }
+
+    protected function renderBackgroundURL(): void
+    {
+        $panel = $this->manager->read(file_get_contents($this->backgroundURL));
+
+        $imagick = $panel->core()->native();
+
+        $imagick->setImageVirtualPixelMethod(1);
+        $imagick->setImageAlphaChannel(Imagick::ALPHACHANNEL_ACTIVATE);
+
+        $imagick->evaluateImage(Imagick::EVALUATE_MULTIPLY, $this->backgroundOpacity, Imagick::CHANNEL_ALPHA);
+
+        $width = $panel->width();
+        $height = $panel->height();
+
+        $columns = ceil($this->width / $width);
+        $rows = ceil($this->height / $height);
+
+        $panel->resize($this->width, $this->height, function ($constraint) {
+            $constraint->aspectRatio();
+            $constraint->upsize();
+        });
+
+        $filledRows = 0;
+
+        while ($filledRows <= $rows) {
+            $filledColumns = 0;
+
+            while ($filledColumns <= $columns) {
+                $this->image->place(
+                    element: $panel,
+                    offset_x: $filledColumns * $width,
+                    offset_y: $filledRows * $height,
+                );
+
+                $filledColumns++;
+            }
+
+            $filledRows++;
+        }
+    }
 }

tests/test_with_url.php

@@ -0,0 +1,14 @@
+<?php
+
+use SimonHamp\TheOg\Image;
+
+include_once __DIR__.'/../vendor/autoload.php';
+
+(new Image())
+    ->accentColor('#cc0000')
+    ->border()
+    ->url('https://example.com/blog/some-blog-post-url')
+    ->title('Some blog post title that is quite big and quite long')
+    ->description('Some slightly smaller but potentially much longer subtext. It could be really long so we might need to trim it completely after many words')
+    ->backgroundURL('https://www.goodfreephotos.com/albums/animals/mammals/african-bush-elephant-loxodonta-africana.jpg', 0.2) // CC0 licensed image from https://www.goodfreephotos.com/
+    ->save(__DIR__.'/test_background_url.png');