利用php创建打印文字动画效果

以下是代码片段：
< ?php 
/** 
* 打印机打印效果 
* @ param $text String 需要打印的文字 
* @ param $color color|#16进制颜色  
* @ param $fontsize int 字体大小 
**/ 
  
function gif_print($text,$color=’red’,$fontsize = 40) 
{ 
    $ani = new Imagick(); 
    $ani->setFormat(’gif’); 
    $textcolor = new ImagickPixel($color); 
    $bgcolor = new ImagickPixel(’white’); 
  
    //定义画笔 
    $draw = new ImagickDraw(); 
    $draw->setFontSize($fontsize); 
    $draw->setFillColor($textcolor); 
    $draw->setGravity(imagick::GRAVITY_WEST); 
  
    //获取画笔写字的属性 
    $fontprop = $ani->queryFontMetrics($draw,$text); 
    $width = (int)$fontprop[’textWidth’] + 8; 
    $height = (int)$fontprop[’textHeight’]  ; 
  
    //创建打印机的待机效果 
  
    $ani->newImage($width,$height,$bgcolor); 
    $draw->line(3,8,3,$height); 
    $ani->drawimage($draw); 
    $ani->setImageDelay(30); 
    $ani->newImage($width,$height,$bgcolor); 
    $ani->setImageDelay(30); 
    $ani->newImage($width,$height,$bgcolor); 
  
    $ani->drawimage($draw); 
    $ani->setImageDelay(30); 
  
    $textstrlen = strlen($text); 
  
    //创建打印机打印效果 
    for($i = 0;$i < = $textstrlen;$i++) 
    { 
        $single = substr($text,0,$i); 
        $ani->newImage($width,$height,$bgcolor); 
        $ani->setGravity(imagick::GRAVITY_WEST); 
        $ani->annotateImage($draw,0,0,0,$single); 
        $ani->setImageDelay(20); 
    } 
  
    header("Content-Type:image/gif"); 
    echo $ani->getImagesBlob(); 
} 
gif_print(’Welcome to Paitoubing.cn’,’blue’,30);