怎么使用php的gd库画一条抗锯齿的粗斜线

如何使用php的gd库画一条抗锯齿的粗斜线?
如题，使用多边形画的填充图是有锯齿的。imageantialias函数是无效的。

------解决方案--------------------
点阵图有锯齿是必然的
imageantialias 的抗锯齿是有作用的，你可以对比他打开和关闭时的效果
如果你对 imageantialias 的效果不满意（毕竟GD不是专业的图像处理包），那就要你自己编程解决了

------解决方案--------------------
他是扰码加密的，有空研究一下
------解决方案--------------------
好无聊啊，最终是用 js 实现的
------解决方案--------------------
JS有现成的插件 做出来的很漂亮。。。用PHP干嘛
------解决方案--------------------
给你一个早年写的代码，供参考

PHP code

create(func_get_arc(0),func_get_arc(1));
    else
        $this->create(400,300);
  }
  /**
   * 在($x,$y)处画点
   */
  function pixel($x,$y) {
    $p = $this->get_view($x,$y);
    imagesetpixel($this->im,$p['x'],$p['y'],$this->color);
    $this->xo = $p['x'];
    $this->yo = $p['y'];
  }
  /**
   * 移动到($x,$y)处
   */
  function moveto($x,$y) {
    $p = $this->get_view($x,$y);
    $this->xo = $p['x'];
    $this->yo = $p['y'];
  }
  /**
   * 从($x1,$y1)到($x2,$y2)处画线
   */
  function line($x1,$y1,$x2,$y2) {
    $p1 = $this->get_view($x1,$y1);
    $p2 = $this->get_view($x2,$y2);
    imageline($this->im,$p1['x'],$p1['y'],$p2['x'],$p2['y'],$this->color);
  }
  /**
   * 从当前位置到($x,$y)处画线
   */
  function lineto($x,$y) {
    $p = $this->get_view($x,$y);
    imageline($this->im, $this->xo, $this->yo, $p['x'], $p['y'], $this->color);
    $this->xo = $p['x'];
    $this->yo = $p['y'];
  }
  /**
   * 设置当前颜色
   */
  function color($clr) {
    $r = ($clr>>16) & 0xff; 
    $g = ($clr>>8) & 0xff; 
    $b = ($clr) & 0xff; 
    $this->color = ImageColorAllocate($this->im, $r,$g,$b);
    $this->fillcolor = ImageColorAllocate($this->im, $r,$g,$b);
    $this->filldarkcolor = ImageColorAllocate($this->im, $r/2,$g/2,$b/2);
    return $this->color;
  }
  /**
   * 设置当前充填颜色
   */
  function fillcolor($clr) {
    $r = ($clr>>16) & 0xff; 
    $g = ($clr>>8) & 0xff; 
    $b = ($clr) & 0xff; 
    $this->fillcolor = ImageColorAllocate($this->im, $r,$g,$b);
    return $this->fillcolor;
  }
  /**
   * 创建GD句柄并设置坐标系
   */
  function create($x,$y) {
    $this->im = imagecreatetruecolor($x,$y);
imageantialias($this->im, 1);
imagefill($this->im, 0, 0, $this->color(0xffffff));
    $this->viewx = $x-1;
    $this->viewy = -($y-1);
    $this->winx = $x;
    $this->winy = $y;
    $this->orgx = 0;
    $this->orgy = 0;//$y;
    $this->colors = $this->color(0xffffff);

    settype($this->ksin,"double");
    settype($this->kcos,"double");
    $this->ksin = sin(deg2rad(0));
    $this->kcos = cos(deg2rad(0));
  }
  /**
   * 坐标映射
   */
  function get_view($x,$y) {
    $this->xo = $x*$this->kcos - $y*$this->ksin;
    $this->yo = $x*$this->ksin + $y*$this->kcos;
    $p['x'] = ($this->xo + $this->orgx)*($this->viewx/$this->winx);
    $p['y'] = ($this->yo + $this->orgy)*($this->viewy/$this->winy)-$this->viewy;
    return $p;
  }
  /**
   * 设置限度
   */
  function set_ext($x,$y=0) {
    $this->winx = $x;
    if($y == 0) {
        $this->winy = - $x * $this->viewy / $this->viewx;
    }else {
        $this->winy = $y;
    }
  }
  /**
   * 设置旋转角
   */
  function set_r($p) {
    $this->ksin = sin(deg2rad($p));
    $this->kcos = cos(deg2rad($p));
  }
  /**
   * 构造图形，必需在派生类中重载本方法
   */
  function paint() {
    /**
     * 必需由派生类重载
     * 必需包含语句 $this->create(宽度,高度);
     */
    die("paint 方法必需由派生类重载!");
  }
  /**
   * 输出图形
   */
  function run() {
    $this->paint();
    $func = "Image".$this->type;
    if(! function_exists($func)) {
        $this->type = "png";
        $func = "Image".$this->type;
    }
    Header("Content-type: image/{$this->type}");
    $func($this->im);
    imageDestroy($this->im);
  }

  /**
   * 圆类图形数据生成，参数$p为坐标旋转角
   */
  function get_point($ox,$oy,$w,$h,$start,$end) {
    $a = $w/2;
    $b = $h/2;
    $rs = array();
    $i = $start;
    for($i=$start;$iget_view($ox+$x,$oy+$y);
        $rs[] = $p['x'];
        $rs[] = $p['y'];
        if($i == $end) break;
        if($i+5 > $end) $i = $end - 5;
    }
    $p = $this->get_view($ox,$oy);
    $rs[] = $p['x'];
    $rs[] = $p['y'];
    $rs[] = $rs[0];
    $rs[] = $rs[1];
    return $rs;
  }
  /**
   * 弓形
   */
  function chord($left,$top,$w,$h,$start,$end,$z=0) {
    $ar = $this->get_point($left,$top,$w,$h,$start,$end,$p);
    for($i=0;$iget_view($ar[$i],$ar[$i+1]);
        $ar[$i] = $p['x'];
        $ar[$i+1] = $p['y'];
    }
    imagefilledpolygon($this->im,$ar,count($ar)/2-1,$this->fillcolor);
    imagepolygon($this->im,$ar,count($ar)/2-1,$this->color);
  }
  /**
   * 扇形
   */
  function pie($left,$top,$w,$h,$start,$end,$z=0) {
    $this->get_view($left,$top+$z);
    $ar = $this->get_point($left,$top+$z,$w,$h,$start,$end);
    $this->get_view($left,$top);
    $arh = $this->get_point($left,$top,$w,$h,$start,$end);
    for($j=0;$jfilltype)
            imagefilledpolygon($this->im,$t,4,$this->filldarkcolor);
        else
            imagepolygon($this->im,$t,4,$this->color);
    }
    if($this->filltype)
        imagefilledpolygon($this->im,$ar,count($ar)/2-1,$this->fillcolor);
  }
  /**
   * 弧形
   */
  function arc($left,$top,$w,$h,$start,$end,$z=0) {
    $ar = $this->get_point($left,$top,$w,$h,$start,$end,$p);
    $this->moveto($ar[0],$ar[1]);
    for($i=2;$ilineto($ar[$i],$ar[$i+1]);
  }
}

/**
 * 重载基类的paint方法
 */
class myGraph extends Graph {
  function paint() {
//    $this->create(400,300);
    $this->create(200,150);
$this->set_ext(400);
    $this->set_r(10); // 旋转
    $this->filltype = false; //充填
    $k = 40;    //高
    $a =200;    //中心x
    $b = 150;    //中心y
    $c = 200;    //长轴
    $d = 100;    //短轴

    $this->color(0x000000);
    $this->color(0xff0000);
    $this->pie($a,$b,$c,$d,0,100,$k);
    $this->color(0x00ff00);
    $this->pie($a,$b,$c,$d,120,240,$k);
    $this->color(0x0000ff);
    $this->pie($a+10,$b-10,$c,$d,240,360,$k);
    $this->color(0x8080ff);
    $this->pie(50,80,40,20,0,360,50);
    $this->line($a,0,$a,$b*2);
    $this->line(0,$b,$a*2,$b);
  }
}

$g = new myGraph;
$g->run();