How can PHP developers ensure that the images are stacked vertically rather than on top of each other when merging?

To ensure that images are stacked vertically rather than on top of each other when merging, PHP developers can calculate the height of each image and adjust the position of the next image accordingly. By keeping track of the total height of the merged image, developers can accurately position each subsequent image below the previous one.

$mergedImage = imagecreatetruecolor($width, $height);

$currentHeight = 0;

foreach ($images as $image) {
    $imageWidth = imagesx($image);
    $imageHeight = imagesy($image);
    
    imagecopy($mergedImage, $image, 0, $currentHeight, 0, 0, $imageWidth, $imageHeight);
    
    $currentHeight += $imageHeight;
}

// Save or output the merged image