PHP GD库---之微信朋友圈9张图

$item_pic = "img/item.jpg";

list($width, $height) = getimagesize($item_pic);

$item_pic = imagecreatefromjpeg($item_pic);

$avg_width = ceil($width / 3);
$avg_height = ceil($height / 3);

// 创建画布
for ($i = 1; $i < 10; $i++) {

    $image = imagecreatetruecolor($avg_width, $avg_height);

    list($source_width, $source_height) = get_source_width_height($avg_width, $avg_height, $i);

    imagecopyresampled($image, $item_pic, 0, 0, $source_width, $source_height, $avg_height, $avg_height, $avg_height, $avg_height);

    imagejpeg($image, 'img/'.$i.'.jpg');

    imagedestroy($image);

}

function get_source_width_height ($avg_width, $avg_height, $i) {

    switch ($i) {
        case 1:
            $return_width = 0;
            $return_height = 0;
            break;
        case 2:
            $return_width = $avg_width;
            $return_height = 0;
            break;
        case 3:
            $return_width = $avg_width * 2;
            $return_height = 0;
            break;
        case 4:
            $return_width = 0;
            $return_height = $avg_height;
            break;
        case 5:
            $return_width = $avg_width ;
            $return_height = $avg_height;
            break;
        case 6:
            $return_width = $avg_width * 2;
            $return_height = $avg_height;
            break;
        case 7:
            $return_width = 0;
            $return_height = $avg_height * 2;
            break;
        case 8:
            $return_width = $avg_width;
            $return_height = $avg_height * 2;
            break;
        case 9:
            $return_width = $avg_width * 2;
            $return_height = $avg_height * 2;
            break;
        default;
    }
    return [$return_width, $return_height];
}

　　效果