php生成文字png图片的函数

<?
/*
php生成文字png图片，调用方式:
http://www.yourdomian.com/text_png.php3?msg=helloworld+class&rot=15&size=48&font=fonts/ARIAL.TTF
 
*/
 
Header("Content-type: image/png");
 
class textPNG {
    var $font = 'fonts/TIMES.TTF'; //默认字体. 相对于脚本存放目录的相对路径.
    var $msg = "undefined"; // 默认文字.
    var $size = 24;
    var $rot = 0; // 旋转角度.
    var $pad = 0; // 填充.
    var $transparent = 1; // 文字透明度.
    var $red = 0; // 在黑色背景中...
    var $grn = 0;
    var $blu = 0;
    var $bg_red = 255; // 将文字设置为白色.
    var $bg_grn = 255;
    var $bg_blu = 255;
 
function draw() {
    $width = 0;
    $height = 0;
    $offset_x = 0;
    $offset_y = 0;
    $bounds = array();
    $image = "";
 
    // 确定文字高度.
    $bounds = ImageTTFBBox($this->size, $this->rot, $this->font, "W");
    if ($this->rot < 0) {
        $font_height = abs($bounds[7]-$bounds[1]);
    } else if ($this->rot > 0) {
        $font_height = abs($bounds[1]-$bounds[7]);
    } else {
        $font_height = abs($bounds[7]-$bounds[1]);
    }
 
    // 确定边框高度.
    $bounds = ImageTTFBBox($this->size, $this->rot, $this->font, $this->msg);
    if ($this->rot < 0) {
        $width = abs($bounds[4]-$bounds[0]);
        $height = abs($bounds[3]-$bounds[7]);
        $offset_y = $font_height;
        $offset_x = 0;
 
    } else if ($this->rot > 0) {
        $width = abs($bounds[2]-$bounds[6]);
        $height = abs($bounds[1]-$bounds[5]);
        $offset_y = abs($bounds[7]-$bounds[5])+$font_height;
        $offset_x = abs($bounds[0]-$bounds[6]);
 
    } else {
        $width = abs($bounds[4]-$bounds[6]);
        $height = abs($bounds[7]-$bounds[1]);
        $offset_y = $font_height;;
        $offset_x = 0;
    }
 
    $image = imagecreate($width+($this->pad*2)+1,$height+($this->pad*2)+1);
 
    $background = ImageColorAllocate($image, $this->bg_red, $this->bg_grn, $this->bg_blu);
    $foreground = ImageColorAllocate($image, $this->red, $this->grn, $this->blu);
 
    if ($this->transparent) ImageColorTransparent($image, $background);
    ImageInterlace($image, false);
 
    // 画图.
    ImageTTFText($image, $this->size, $this->rot, $offset_x+$this->pad, $offset_y+$this->pad, $foreground, $this->font, $this->msg);
 
    // 输出为png格式.
    imagePNG($image);
}
}
 
$text = new textPNG;
 
if (isset($msg)) $text->msg = $msg; // 需要显示的文字
if (isset($font)) $text->font = $font; // 字体
if (isset($size)) $text->size = $size; // 文字大小
if (isset($rot)) $text->rot = $rot; // 旋转角度
if (isset($pad)) $text->pad = $pad; // padding
if (isset($red)) $text->red = $red; // 文字颜色
if (isset($grn)) $text->grn = $grn; // ..
if (isset($blu)) $text->blu = $blu; // ..
if (isset($bg_red)) $text->bg_red = $bg_red; // 背景颜色.
if (isset($bg_grn)) $text->bg_grn = $bg_grn; // ..
if (isset($bg_blu)) $text->bg_blu = $bg_blu; // ..
if (isset($tr)) $text->transparent = $tr; // 透明度 (boolean).
 
$text->draw();
?>