public function createOnlineCourseCertsImgFront($data=array())
    {
        $name = $data['name'];//姓名
        $idnum = $data['idnum'];//证书编号
        $validtime = $data['validtime'];//有效期
        $sex=$data['sex'];//性别
        $sex==1 && $sex='男';
        $sex==2 && $sex='女';
        $sex==0 && $sex='未知';
        $certtime=$data['certtime'];//证书开始时间
        $filename=$data['filename'];//文件名
        $path_2=$data['path_2'];//头像文件
        
            
        //背景图片
        $path_1 = ROOT_PATH . 'public/uploads/certsimg/online_frontbackground.png';
    

        //创建图片对象
        $image_1 = imagecreatefrompng($path_1);
     
        $image_2 = imagecreatefrompng($path_2);
    
 
        $background = imagecolorexact($image_1, 0, 0, 0);
        imagecolortransparent($image_1, $background);
        imagealphablending($image_1, false);
        imagesavealpha($image_1, true);

        //合成图片
        imagecopymerge($image_1, $image_2, 49, 111, 0, 0, imagesx($image_2), imagesy($image_2), 100);
    
        //设置文字颜色
        $black = imagecolorallocate($image_1, 0, 0, 0);
    
        //写的文字用到的字体
        $font = ROOT_PATH . 'public/uploads/certsimg/simfang.ttf';
    
        //在图片里插入文字$black
        imagettftext($image_1, 20, 0, 339, 130, $black,$font, $name);
        imagettftext($image_1, 20, 0, 555, 130, $black,$font, $sex);
        imagettftext($image_1, 20, 0, 339, 188, $black, $font, $idnum);
        imagettftext($image_1, 20, 0, 339, 243, $black, $font, $certtime);
        imagettftext($image_1, 20, 0, 339, 293, $black, $font, $validtime);
    
        //这是合成后的图片保存的路径
        $upload_dir = "public/uploads/certsimg/";
    
        imagepng($image_1, ROOT_PATH . $upload_dir . $filename . '.png');
    
        $finalurl='uploads/certsimg/'.$filename . '.png';
    
        return  $finalurl;
    
    }