?php
class ImageTool
{
  private $imagePath;//圖片路徑
  private $outputDir;//輸出文件夾
  private $memoryImg;//內存圖像
  public function __construct($imagePath, $outputDir = null)
  {
    $this->imagePath = $imagePath;
    $this->outputDir = $outputDir;
    $this->memoryImg = null;
  }
  /**
   * 顯示內存中的圖片
   * @param $image
   */
  public function showImage()
  {
    if ($this->memoryImg != null) {
      $info = getimagesize($this->imagePath);
      $type = image_type_to_extension($info[2], false);
      header('Content-type:' . $info['mime']);
      $funs = "image{$type}";
      $funs($this->memoryImg);
      imagedestroy($this->memoryImg);
      $this->memoryImg = null;
    }
  }
  /**將圖片以文件形式保存
   * @param $image
   */
  private function saveImage($image)
  {
    $info = getimagesize($this->imagePath);
    $type = image_type_to_extension($info[2], false);
    $funs = "image{$type}";
    if (empty($this->outputDir)) {
      $funs($image, md5($this->imagePath) . '.' . $type);
    } else {
      $funs($image, $this->outputDir . md5($this->imagePath) . '.' . $type);
    }
  }
  /**
   * 壓縮圖片
   * @param $width 壓縮后寬度
   * @param $height 壓縮后高度
   * @param bool $output 是否輸出文件
   * @return resource
   */
  public function compressImage($width, $height, $output = false)
  {
    $image = null;
    $info = getimagesize($this->imagePath);
    $type = image_type_to_extension($info[2], false);
    $fun = "imagecreatefrom{$type}";
    $image = $fun($this->imagePath);
    $thumbnail = imagecreatetruecolor($width, $height);
    imagecopyresampled($thumbnail, $image, 0, 0, 0, 0, $width, $height, $info[0], $info[1]);
    imagedestroy($image);
    if ($output) {
      $this->saveImage($thumbnail);
    }
    $this->memoryImg = $thumbnail;
    return $this;
  }
  /**
   * 為圖像添加文字標記
   *
   * @param $content 文本內容
   * @param $size 字體大小
   * @param $font 字體樣式
   * @param bool $output 是否輸出文件
   * @return $this
   */
  public function addTextmark($content, $size, $font, $output = false)
  {
    $info = getimagesize($this->imagePath);
    $type = image_type_to_extension($info[2], false);
    $fun = "imagecreatefrom{$type}";
    $image = $fun($this->imagePath);
    $color = imagecolorallocatealpha($image, 0, 0, 0, 80);
    $posX = imagesx($image) - strlen($content) * $size / 2;
    $posY = imagesy($image) - $size / 1.5;
    imagettftext($image, $size, 0, $posX, $posY, $color, $font, $content);
    if ($output) {
      $this->saveImage($image);
    }
    $this->memoryImg = $image;
    return $this;
  }
  /**
   * 為圖片添加水印
   *
   * @param $watermark 水印圖片路徑
   * @param $alpha 水印透明度(0-100)
   * @param bool $output 是否輸出文件
   * @return $this
   */
  public function addWatermark($watermark, $alpha, $output = false)
  {
    $image_info = getimagesize($this->imagePath);
    $image_type = image_type_to_extension($image_info[2], false);
    $image_fun = "imagecreatefrom{$image_type}";
    $image = $image_fun($this->imagePath);
    $mark_info = getimagesize($watermark);
    $mark_type = image_type_to_extension($mark_info[2], false);
    $mark_fun = "imagecreatefrom{$mark_type}";
    $mark = $mark_fun($watermark);
    $posX = imagesx($image) - imagesx($mark);
    $posY = imagesy($image) - imagesy($mark);
    imagecopymerge($image, $mark, $posX, $posY, 0, 0, $mark_info[0], $mark_info[1], $alpha);
    if ($output) {
      $this->saveImage($image);
    }
    $this->memoryImg = $image;
    return $this;
  }
}

require_once 'ImageTool.class.php';

$imageTool = new ImageTool('img/oppman.jpeg', 'out/');//圖片路徑、輸出文件夾

$imageTool->compressImage(350, 250, true);//壓縮寬度、壓縮高度、是否保存
$imageTool->showImage();

$imageTool->addTextmark('一拳超人', 50, 'res/micro.ttf', true);//內容、尺寸、字體、是否保存
$imageTool->showImage();

$imageTool->addWatermark('res/logo.jpeg', 100, true);//水印路徑、透明度、是否保存
$imageTool->showImage();

$imageTool->addTextmark('快捷輸出', 50, 'res/micro.ttf')->showImage();