$start_y 起始位置Y(当选定方位模式裁剪时，此参数不起作用)
* @return 裁剪图片存储路径
*/
function thumb($src_file, $new_width, $new_height, $type = 1, $pos = 5, $start_x = 0, $start_y = 0) {
$pathinfo = pathinfo($src_file);
$dst_file = $pathinfo['dirname'] . '/' . $pathinfo['filename'] .'_'. $new_width . 'x' . $new_height . '.' . $pathinfo['extension'];
if (!file_exists($dst_file)) {
if ($new_width < 1 || $new_height < 1) {
echo "params width or height error !";
exit();
}
if (!file_exists($src_file)) {
echo $src_file . " is not exists !";
exit();
}
// 图像类型
$img_type = exif_imagetype($src_file);
$support_type = array(IMAGETYPE_JPEG, IMAGETYPE_PNG, IMAGETYPE_GIF);
if (!in_array($img_type, $support_type, true)) {
echo "只支持jpg、png、gif格式图片裁剪";
exit();
}
/* 载入图像 */
switch ($img_type) {
case IMAGETYPE_JPEG :
$src_img = imagecreatefromjpeg($src_file);
break;
case IMAGETYPE_PNG :
$src_img = imagecreatefrompng($src_file);
break;
case IMAGETYPE_GIF :
$src_img = imagecreatefromgif($src_file);
break;
default:
echo "载入图像错误!";
exit();
}
/* 获取源图片的宽度和高度 */
$src_width = imagesx($src_img);
$src_height = imagesy($src_img);
/* 计算剪切图片的宽度和高度 */
$mid_width = ($src_width < $new_width) ? $src_width : $new_width;
$mid_height = ($src_height < $new_height) ? $src_height : $new_height;
/* 初始化源图片剪切裁剪的起始位置坐标 */
switch ($pos * $type) {
case 1://1为顶端居左
$start_x = 0;
$start_y = 0;
break;
case 2://2为顶端居中
$start_x = ($src_width - $mid_width) / 2;
$start_y = 0;
break;
case 3://3为顶端居右
$start_x = $src_width - $mid_width;
$start_y = 0;
break;
case 4://4为中部居左
$start_x = 0;
$start_y = ($src_height - $mid_height) / 2;
break;
case 5://5为中部居中
$start_x = ($src_width - $mid_width) / 2;
$start_y = ($src_height - $mid_height) / 2;
break;
case 6://6为中部居右
$start_x = $src_width - $mid_width;
$start_y = ($src_height - $mid_height) / 2;
break;
case 7://7为底端居左
$start_x = 0;
$start_y = $src_height - $mid_height;
break;
case 8://8为底端居中
$start_x = ($src_width - $mid_width) / 2;
$start_y = $src_height - $mid_height;
break;
case 9://9为底端居右
$start_x = $src_width - $mid_width;
$start_y = $src_height - $mid_height;
break;
default://随机
break;
}
// 为剪切图像创建背景画板
$mid_img = imagecreatetruecolor($mid_width, $mid_height);
//拷贝剪切的图像数据到画板，生成剪切图像
imagecopy($mid_img, $src_img, 0, 0, $start_x, $start_y, $mid_width, $mid_height);
// 为裁剪图像创建背景画板
$new_img = imagecreatetruecolor($new_width, $new_height);
//拷贝剪切图像到背景画板，并按比例裁剪
imagecopyresampled($new_img, $mid_img, 0, 0, 0, 0, $new_width, $new_height, $mid_width, $mid_height);
/* 按格式保存为图片 */
switch ($img_type) {
case IMAGETYPE_JPEG :
imagejpeg($new_img, $dst_file, 100);
break;
case IMAGETYPE_PNG :
imagepng($new_img, $dst_file, 9);
break;
case IMAGETYPE_GIF :
imagegif($new_img, $dst_file, 100);
break;
default:
break;
}
}
return ltrim($dst_file, '.');
}
