php实现生成code128条形码的方法详解

<?php
class barcode128 {
  const starta = 103;
  const startb = 104;
  const startc = 105;
  const stop = 106;
  private $unit_width = 1; //单位宽度 缺省1个象素
  private $is_set_height = false;
  private $width = -1;
  private $heith = 35;
  private $quiet_zone = 6;
  private $font_height = 15;
  private $font_type = 4;
  private $color =0x000000;
  private $bgcolor =0xffffff;
  private $image = null;
  private $codes = array("212222","222122","222221","121223","121322","131222","122213","122312","132212","221213","221312","231212","112232","122132","122231","113222","123122","123221","223211","221132","221231","213212","223112","312131","311222","321122","321221","312212","322112","322211","212123","212321","232121","111323","131123","131321","112313","132113","132311","211313","231113","231311","112133","112331","132131","113123","113321","133121","313121","211331","231131","213113","213311","213131","311123","311321","331121","312113","312311","332111","314111","221411","431111","111224","111422","121124","121421","141122","141221","112214","112412","122114","122411","142112","142211","241211","221114","413111","241112","134111","111242","121142","121241","114212","124112","124211","411212","421112","421211","212141","214121","412121","111143","111341","131141","114113","114311","411113","411311","113141","114131","311141","411131","211412","211214","211412","2331112");
  private $valid_code = -1;
  private $type ='b';
  private $start_codes =array('a'=>self::starta,'b'=>self::startb,'c'=>self::startc);
  private $code ='';
  private $bin_code ='';
  private $text ='';
  public function __construct($code='',$text='',$type='b')
  {
    if (in_array($type,array('a','b','c')))
      $this->settype($type);
    else
      $this->settype('b');
    if ($code !=='')
      $this->setcode($code);
    if ($text !=='')
      $this->settext($text);
  }
  public function setunitwidth($unit_width)
  {
    $this->unit_width = $unit_width;
    $this->quiet_zone = $this->unit_width*6;
    $this->font_height = $this->unit_width*15;
    if (!$this->is_set_height)
    {
      $this->heith = $this->unit_width*35;
    }
  }
  public function setfonttype($font_type)
  {
    $this->font_type = $font_type;
  }
  public function setbgcolor($bgcoloe)
  {
    $this->bgcolor = $bgcoloe;
  }
  public function setcolor($color)
  {
    $this->color = $color;
  }
  public function setcode($code)
  {
    if ($code !='')
    {
      $this->code= $code;
      if ($this->text ==='')
        $this->text = $code;
    }
  }
  public function settext($text)
  {
    $this->text = $text;
  }
  public function settype($type)
  {
    $this->type = $type;
  }
  public function setheight($height)
  {
    $this->height = $height;
    $this->is_set_height = true;
  }
  private function getvaluefromchar($ch)
  {
    $val = ord($ch);
    try
    {
      if ($this->type =='a')
      {
        if ($val > 95)
          throw new exception(' illegal barcode character '.$ch.' for code128a in '.__file__.' on line '.__line__);
        if ($val < 32)
          $val += 64;
        else
          $val -=32;
      }
      elseif ($this->type =='b')
      {
        if ($val < 32 || $val > 127)
          throw new exception(' illegal barcode character '.$ch.' for code128b in '.__file__.' on line '.__line__);
        else
          $val -=32;
      }
      else
      {
        if (!is_numeric($ch) || (int)$ch < 0 || (int)($ch) > 99)
          throw new exception(' illegal barcode character '.$ch.' for code128c in '.__file__.' on line '.__line__);
        else
        {
          if (strlen($ch) ==1)
            $ch .='0';
          $val = (int)($ch);
        }
      }
    }
    catch(exception $ex)
    {
      errorlog('die',$ex->getmessage());
    }
    return $val;
  }
  private function parsecode()
  {
    $this->type=='c'?$step=2:$step=1;
    $val_sum = $this->start_codes[$this->type];
    $this->width = 35;
    $this->bin_code = $this->codes[$val_sum];
    for($i =0;$i<strlen($this->code);$i+=$step)
    {
      $this->width +=11;
      $ch = substr($this->code,$i,$step);
      $val = $this->getvaluefromchar($ch);
      $val_sum += $val;
      $this->bin_code .= $this->codes[$val];
    }
    $this->width *=$this->unit_width;
    $val_sum = $val_sum%103;
    $this->valid_code = $val_sum;
    $this->bin_code .= $this->codes[$this->valid_code];
    $this->bin_code .= $this->codes[self::stop];
  }
  public function getvalidcode()
  {
    if ($this->valid_code == -1)
      $this->parsecode();
    return $this->valid_code;
  }
  public function getwidth()
  {
    if ($this->width ==-1)
      $this->parsecode();
    return $this->width;
  }
  public function getheight()
  {
    if ($this->width ==-1)
      $this->parsecode();
    return $this->height;
  }
  public function createbarcode($image_type ='png',$file_name=null)
  {
    $this->parsecode();
    $this->image = imagecreate($this->width+2*$this->quiet_zone,$this->heith + $this->font_height);
    $this->bgcolor = imagecolorallocate($this->image,$this->bgcolor >> 16,($this->bgcolor >> 8)&0x00ff,$this->bgcolor & 0xff);
    $this->color = imagecolorallocate($this->image,$this->color >> 16,($this->color >> 8)&0x00ff,$this->color & 0xff);
    imagefilledrectangle($this->image, 0, 0, $this->width + 2*$this->quiet_zone,$this->heith + $this->font_height, $this->bgcolor);
    $sx = $this->quiet_zone;
    $sy = $this->font_height -1;
    $fw = 10; //編號為2或3的字體的寬度為10，為4或5的字體寬度為11
    if ($this->font_type >3)
    {
      $sy++;
      $fw=11;
    }
    $ex = 0;
    $ey = $this->heith + $this->font_height - 2;
    for($i=0;$i<strlen($this->bin_code);$i++)
    {
      $ex = $sx + $this->unit_width*(int) $this->bin_code{$i} -1;
      if ($i%2==0)
        imagefilledrectangle($this->image, $sx, $sy, $ex,$ey, $this->color);
      $sx =$ex + 1;
    }
    $t_num = strlen($this->text);
    $t_x = $this->width/$t_num;
    $t_sx = ($t_x -$fw)/2;    //目的为了使文字居中平均分布
    for($i=0;$i<$t_num;$i++)
    {
      imagechar($this->image,$this->font_type,6*$this->unit_width +$t_sx +$i*$t_x,0,$this->text{$i},$this->color);
    }
    if (!$file_name)
    {
      header("content-type: image/".$image_type);
    }
    switch ($image_type)
    {
      case 'jpg':
      case 'jpeg':
        imagejpeg($this->image,$file_name);
        break;
      case 'png':
        imagepng($this->image,$file_name);
        break;
      case 'gif':
        break;
        imagegif($this->image,$file_name);
      default:
        imagepng($this->image,$file_name);
        break;
    }
  }
}
$barcode = new barcode128('88888888');
$barcode->createbarcode();
?>