PHP中用GD绘制饼图

Class Chart{
private $image; // 定义图像
private $title; // 定义标题
private $ydata; // 定义Y轴数据
private $xdata; // 定义X轴数据
private $color; // 定义条形图颜色
private $bgcolor; // 定义图片背景颜色
private $width; // 定义图片的宽
private $height; // 定义图片的长

/*
* 构造函数
* String title 图片标题
* Array xdata 索引数组，X轴数据
* Array ydata 索引数组，数字数组,Y轴数据
*/
function __construct($title,$xdata,$ydata) {
$this->title = $title;
$this->xdata = $xdata;
$this->ydata = $ydata;
$this->color = array('#058DC7', '#50B432', '#ED561B', '#DDDF00', '#24CBE5', '#64E572', '#FF9655', '#FFF263', '#6AF9C4');
}

/*
* 公有方法，设置条形图的颜色
* Array color 颜色数组,元素取值为'#058DC7'这种形式
*/
function setBarColor($color){
$this->color = $color;
}

/*
* 绘制饼图
*/
function mkPieChart() {
$sum = array_sum($this->ydata); // 获取ydata所有元素之和
$start = 0; // 弧的开始角度
$end = 0; // 弧的结束角度
$pieWidth =  300; // 椭圆的长轴
$pieHeight = 220; // 椭圆的短轴
$space = 40; // 椭圆与小矩形的间距
$margin = 20; // 图片的边距
$recWidth = 20; // 小矩形的宽
$recHeight = 15; // 小矩形的高
$titleHeight = 50; // 标题区域的高
// 图片自适应宽与高
$this->width = $pieWidth + $this->arrayLengthMax($this->xdata)*10*4/3 + $space + $recWidth +$margin;
$this->height =  (($pieHeight > count($this->xdata)*25 ) ? $pieHeight : count($this->xdata)*25) + $titleHeight;
// 椭圆中心的坐标
$cx = $pieWidth/2+$margin;
$cy = $pieHeight/2+$titleHeight;

$this->image = imagecreatetruecolor($this->width ,$this->height); // 准备画布
$this->bgcolor = imagecolorallocate($this->image,255,255,255); // 图片的背景颜色
imagefill($this->image,0,0,$this->bgcolor); // 填充背景

// 设置条形图的颜色
$color = array();
foreach($this->color as $col) {
$col = substr($col,1,strlen($col)-1);
$red = hexdec(substr($col,0,2));
$green = hexdec(substr($col,2,2));
$blue = hexdec(substr($col,4,2));
$color[] = imagecolorallocate($this->image ,$red, $green, $blue);
}

// 设置线段的颜色、字体的颜色、字体的路径
$lineColor = imagecolorallocate($this->image ,0xcc,0xcc,0xcc);
$fontColor = imagecolorallocate($this->image, 0x95,0x8f,0x8f);
$fontPath = 'font/simsun.ttc';

// 绘制扇形弧
for($i = 0; $i < 10; $i++) {
foreach($this->ydata as $key => $val) {
$end += 360*$val/$sum;
imagefilledarc($this->image,$cx,$cy-$i,$pieWidth,$pieHeight, $start,$end,$color[$key%count($this->color)],IMG_ARC_PIE);
$start = $end;
}
}

// 绘制小矩形及之后文字说明
$x1 = $pieWidth+$space;
$y1 = $titleHeight ;
foreach($this->ydata as $key => $val) {
imagefilledrectangle($this->image,$x1,$y1,$x1+$recWidth,$y1+$recHeight,$color[$key%count($this->color)]);
imagettftext($this->image,10,0,$x1+$recWidth+5,$y1+$recHeight-2,$fontColor,$fontPath,$this->xdata[$key]);
$y1 += $recHeight + 10;
}

// 绘画标题
$titleStart = ($this->width - 5.5*strlen($this->title))/2;
imagettftext($this->image,11,0,$titleStart,20,$fontColor,$fontPath,$this->title);

// 输出图片
header("Content-Type:image/png");
imagepng($this->image);
}

/*
* 私有方法，求数组中元素长度最大的值
* Array arr 字符串数组，必须是汉字
*/
private function arrayLengthMax($arr) {
$length = 0;
foreach($arr as $val) {
$length = strlen($val) > $length ? strlen($val) : $length;
}
return $length/3;
}

// 析构函数
function __destruct(){
imagedestroy($this->image);
}
}

$xdata = array('测试一','测试二','测试三','测试四','测试五','测试六','测试七','测试八','测试九');
$ydata = array(89,90,90,23,35,45,56,23,56);
$Img = new Chart($title,$xdata,$ydata);
$Img->mkPieChart();