getRealPath()); $image = $this->imageTool->make($imageData); $image->resize(32, 32); $bmpData = $image->encode('png'); $icoData = $this->pngToIco($bmpData, 32, 32); file_put_contents($targetPath, $icoData); } /** * Restore the original favicon image. */ public function restoreOriginal(): void { $targetPath = public_path('favicon.ico'); $original = public_path('icon.ico'); if (!is_writeable($targetPath)) { return; } copy($original, $targetPath); } /** * Convert PNG image data to ICO file format. * Built following the file format info from Wikipedia: * https://en.wikipedia.org/wiki/ICO_(file_format) */ protected function pngToIco(string $bmpData, int $width, int $height): string { // ICO header $header = pack('v', 0x00); // Reserved. Must always be 0 $header .= pack('v', 0x01); // Specifies ico image $header .= pack('v', 0x01); // Specifies number of images // ICO Image Directory $entry = hex2bin(dechex($width)); // Image width $entry .= hex2bin(dechex($height)); // Image height $entry .= "\0"; // Color palette, typically 0 $entry .= "\0"; // Reserved // Color planes, Appears to remain 1 for bmp image data $entry .= pack('v', 0x01); // Bits per pixel, can range from 1 to 32. From testing conversion // via intervention from png typically provides this as 24. $entry .= pack('v', 0x00); // Size of the image data in bytes $entry .= pack('V', strlen($bmpData)); // Offset of the bmp data from file start $entry .= pack('V', strlen($header) + strlen($entry) + 4); // Join & return the combined parts of the ICO image data return $header . $entry . $bmpData; } }