use webp for avatars and convert current avatars, fixes #3183

Closes #3183

Merge request studip/studip!2326

1 files changed, 116 insertions, 0 deletions

diff --git a/db/migrations/5.5.10_convert_avatars_to_webp.php b/db/migrations/5.5.10_convert_avatars_to_webp.php
new file mode 100644
index 0000000..cf120a0
--- /dev/null
+++ b/db/migrations/5.5.10_convert_avatars_to_webp.php
@@ -0,0 +1,116 @@
+<?php
+final class ConvertAvatarsToWebp extends Migration
+{
+    const SIZES = [
+        'small'  => [
+            'default' => [25 * 2, 25 * 2],
+            'license' => [60 * 2, 20 * 2],
+        ],
+        'medium' => [
+            'default' => [100 * 2, 100 * 2],
+            'license' => [120 * 2, 40 * 2],
+        ],
+        'normal' => [
+            'default' => [250 * 2, 250 * 2],
+            'license' => [300 * 2, 100 * 2],
+        ],
+    ];
+
+    protected function up()
+    {
+        foreach (['user', 'course', 'institute', 'licenses'] as $type) {
+            $source_directory = $GLOBALS['DYNAMIC_CONTENT_PATH'] . '/' . $type;
+
+            // Convert original images
+            $iterator = new RegexIterator(
+                new FilesystemIterator($source_directory),
+                '/_original\.png$/i'
+            );
+            foreach ($iterator as $file) {
+                $this->convert($file, $type);
+            }
+
+            // Convert leftover images
+            $iterator = new RegexIterator(
+                new FilesystemIterator($source_directory),
+                '/_normal\.png$/i'
+            );
+            foreach ($iterator as $file) {
+                $this->convert($file, $type);
+            }
+        }
+    }
+
+    private function convert(
+        SplFileInfo $input_file,
+        string $type
+    ): void {
+        $input_image = imagecreatefromstring(file_get_contents($input_file->getPathname()));
+
+        if ($input_image === false) {
+            unlink($input_file->getPathname());
+            return;
+        }
+
+        $user_id = explode('_', $input_file->getBasename('.png'))[0];
+        $output_path = $input_file->getPath();
+        if ($type !== 'licenses') {
+            $output_path .= '/' . substr($user_id, 0, 2);
+        }
+        if (!is_dir($output_path)) {
+            mkdir($output_path);
+        }
+
+        imagepalettetotruecolor($input_image);
+        imagealphablending($input_image, false);
+        imagesavealpha($input_image, true);
+
+        $image_width = imagesx($input_image);
+        $image_height = imagesy($input_image);
+
+        foreach (array_keys(self::SIZES) as $size) {
+            [$width, $height] = self::SIZES[$size][$type] ?? self::SIZES[$size]['default'];
+            $output_file = "{$output_path}/{$user_id}_{$size}.webp";
+
+            $factor = min($width / $image_width, $height / $image_height);
+            $resized_width  = round($image_width * $factor);
+            $resized_height = round($image_height * $factor);
+
+            $xpos = intval($width - $resized_width) >> 1;
+            $ypos = intval($height - $resized_height) >> 1;
+
+            $output_image = $this->createNewImage($width, $height);
+
+            imagecopyresampled(
+                $output_image, $input_image,
+                $xpos, $ypos,
+                0, 0,
+                $resized_width, $resized_height,
+                $image_width, $image_height
+            );
+
+            imagewebp($output_image, $output_file, 90);
+            imagedestroy($output_image);
+        }
+
+        imagedestroy($input_image);
+
+        unlink($input_file->getPath() . '/' . $user_id . '_original.png');
+        foreach (array_keys(self::SIZES) as $size) {
+            unlink($input_file->getPath() . '/' . $user_id . '_' . $size . '.png');
+            unlink($input_file->getPath() . '/' . $user_id . '_' . $size . '@2x.png');
+        }
+    }
+
+    private function createNewImage(int $width, int $height)
+    {
+        $image = imagecreatetruecolor($width, $height);
+        imagealphablending($image, false);
+        imagesavealpha($image, false); // Otherwise, WebP won't store the alpha information
+
+        $transparent_color = imagecolorallocatealpha($image, 0, 0, 0, 127);
+        imagefill($image, 0, 0, $transparent_color);
+
+        return $image;
+    }
+}