PHP实现将几张照片拼接到一起的合成图片功能【便于整体打印输出】

<"\n");
 die();
}
// 自然排序
usort($jpgs, "strnatcmp");
foreach($g_tasks as $page=>$photos){
 $files = array();
 foreach($photos as $r){
  $files[] = $jpgs[$r];
 }
 $image_all = imagemake($files);
 $filename = $page.'.jpg';
 imagejpeg($image_all, $dst_path.'/'.$filename);
 unset($files);
 echo $filename.nl2br("\n");
}
echo 'ok'.nl2br("\n");
die();
/**
 * 合成图片
 * @param array $images 本页图片集合
 * @return resource 合成后的图片
 */
function imagemake($files=array()){
 global $g_width,$g_height,$g_models;
 // 合成后的图片
 $image_all = imageCreatetruecolor($g_width,$g_height);
 // 为真彩色画布创建白色背景
 $color = imagecolorallocate($image_all, 255, 255, 255);
 imagefill($image_all, 0, 0, $color);
// imageColorTransparent($image_all, $color); // 背景透明
 //function imagecopyresampled ($dst_image, $src_image, $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h)
 // 排版合成
 $type = count($files);
 switch($type){
  case 2:
   break;
  case 1:
  case 3:
  case 4:
   // 用于合成的图片集
   $images = array();
   // 修正图片
   for($i=0;$i<$type;$i++){
    $images[] = imagecropper($files[$i],$g_models[$type][$i]['w'],$g_models[$type][$i]['h']);
   }
   // 排版合成
   for($i=0;$i<$type;$i++){
    imagecopyresampled($image_all,$images[$i],
     $g_models[$type][$i]['x'],$g_models[$type][$i]['y'],0,0,
     $g_models[$type][$i]['w'],$g_models[$type][$i]['h'],imagesx($images[$i]),imagesy($images[$i]));
   }
   break;
  default:
   break;
 }
 return $image_all;
}
/**
 * 修剪图片：居中裁剪等比缩放
 * @param $source_path 原图路径
 * @param $target_width 目标宽度
 * @param $target_height 目标高度
 * @return bool|resource
 */
function imagecropper($source_path, $target_width, $target_height){
 $source_info = getimagesize($source_path);
 $source_width = $source_info[0];
 $source_height = $source_info[1];
 $source_mime = $source_info['mime'];
 $source_ratio = $source_height / $source_width;
 $target_ratio = $target_height / $target_width;
 switch ($source_mime)
 {
  case 'image/gif':
   $source_image = imagecreatefromgif($source_path);
   break;
  case 'image/jpeg':
   $source_image = imagecreatefromjpeg($source_path);
   break;
  case 'image/png':
   $source_image = imagecreatefrompng($source_path);
   break;
  default:
   return false;
   break;
 }
 // 横竖构图不同，旋转
 if(($target_width-$target_height)*($source_width-$source_height)<0){
  // 旋转
  $source_image = imagerotate($source_image, 90, 0);
  $source_width = $source_info[1]; // [0]
  $source_height = $source_info[0]; // [1]
  $source_ratio = $source_height / $source_width;
 }
 // 源图过高
 if ($source_ratio > $target_ratio)
 {
  $cropped_width = $source_width;
  $cropped_height = $source_width * $target_ratio;
  $source_x = 0;
  $source_y = ($source_height - $cropped_height) / 2;
 }
 // 源图过宽
 elseif ($source_ratio < $target_ratio)
 {
  $cropped_width = $source_height / $target_ratio;
  $cropped_height = $source_height;
  $source_x = ($source_width - $cropped_width) / 2;
  $source_y = 0;
 }
 // 源图适中
 else
 {
  $cropped_width = $source_width;
  $cropped_height = $source_height;
  $source_x = 0;
  $source_y = 0;
 }
 $target_image = imagecreatetruecolor($target_width, $target_height);
 $cropped_image = imagecreatetruecolor($cropped_width, $cropped_height);
 // 裁剪
 imagecopy($cropped_image, $source_image, 0, 0, $source_x, $source_y, $cropped_width, $cropped_height);
 // 缩放
 imagecopyresampled($target_image, $cropped_image, 0, 0, 0, 0, $target_width, $target_height, $cropped_width, $cropped_height);
 return $target_image;
}