php 方便水印和缩略图的图形类

<?php /* 
*@author    夜无眠    [e-mail] 
*copyright    http://www.gowake.cn 
*/ 
class img { 
    function __construct($arg = null) { 
        $args = func_get_args(); 
        if($arg == null) { 
            return null; 
        } 
        $this->im = call_user_func_array(array($this,'create'),$args); 
    } 
    function __call($func,$arg) { 
        if(function_exists('image'.$func)) { 
            $funcstr = 'image'.$func; 
        }elseif (function_exists($func)){ 
            $funcstr = $func; 
        }else { 
            error("没有这个类方法或函数"); 
        } 
        return call_user_func_array($funcstr,$arg); 
    } 
    /* 
    *创建图像 
    *@param string/int 图片文件路径或者宽度 
    *@param int 高度，可省略 
    *@param string 6位16进制整数 
    */ 
    function create($arg = null) { 
        $args = func_get_args(); 
        if(is_file($args[0])) { 
            $this->file = $args[0]; 
            $size = getimagesize($this->file) or error('图片类型错误'); 
            $this->size = $this->size ? $this->size : $size; 
            $type = image_type_to_extension($size[2],false); 
            $this->type = $this->type ? $this->type : $type; 
            $createfunc = 'imagecreatefrom'.$type; 
            $im = $createfunc($this->file); 
        }elseif((int)$args[0]>0 and (int)$args[1]>0) { 
            $im = imagecreatetruecolor((int)$args[0],(int)$args[1]) or error("对不起，参数错误！"); 
            if(!$args[2]) { 
                $color = hexdec('7fffffff'); 
                imagecolortransparent($im,$color); 
            }else { 
                $color = hexdec(str_replace('#','',$args[2])); 
            } 
            $this->size = $this->size ? $this->size : array((int)$args[0] ,(int)$args[1]); 
            imagefill($im, 1, 1, $color); 
        }else { 
            error("对不起，参数错误！"); 
        } 
        //imagealphablending($im,false);//这两行用来记录透明通道 
        imagesavealpha($im,true); 
        imageinterlace($im,true);//开启隔行扫描 
        return $im; 
    } 
    /* 
    *生成缩略图 
    *@param int $w 新图片的宽度 
    *@param int $h 新图片的宽度 
    *@param string/bool $color 可选，新图片的背景色，false或空为透明 
    *@param bool $lashen 可选，是否拉伸，默认不拉伸 
    */ 
    function suolue($w = null,$h = null,$color = false,$lashen = false) { 
        $w_o = imagesx($this->im); 
        $h_o = imagesy($this->im); 
        if($w == null and $h != null) { 
            $w = $h * $w_o/$h_o; 
        }elseif ($w != null and $h == null){ 
            $h = $w * $h_o/$w_o; 
        } 
        $this->size = null; 
        $im = $this->create($w,$h,$color); 
        $w_n = $w; 
        $h_n = $h; 
        if($w_o/$h_o > $w/$h) { 
            $h_n = $w*$h_o/$w_o; 
            $y = ($h-$h_n)/2; 
        }elseif ($w_o/$h_o < $w/$h){ 
            $w_n = $h*$w_o/$h_o; 
            $x = ($w-$w_n)/2; 
        } 
        if($lashen) { 
            $w_n = $w; 
            $h_n = $h; 
            $x = 0; 
            $y = 0; 
        } 
        imagecopyresampled($im,$this->im,$x,$y,0,0,$w_n,$h_n,$w_o,$h_o); 
        //imagedestroy($this->im); 
        $this->im = $im; 
        return $im; 
    } 
    /* 
    *在图片上写字 
    *@param string $str 要写的字符串 
    *@param array $arg 字符串相关的参数，为一个关联数组，left 为距左边距离，right为距右边距离，left优先，top为距顶部距离，bottom为距底部距离，top优先；angle为角度，color为6位数16进制颜色，touming为文字透明度，font为字体文件 
    */ 
    function write($str = '' , $arg = array()) { 
        $size = $arg['size'] ? $arg['size'] : 20; 
        $angle = $arg['angle'] ? $arg['angle'] : 0 ; 
        $color = $arg['color'] ? $arg['color'] : '000000'; 
        $touming = $arg['touming'] ? $arg['touming'] : 100; 
            $touming = dechex((100-$touming)*127/100); 
            $color = hexdec($touming.str_replace("#","",$color)); 
        $font = $arg['font'] ? $arg['font'] : 'arial.ttf'; 
        $boxarr = imagettfbbox($size,$angle,$font,$str); 
        $w = imagesx($this->im); 
        $h = imagesy($this->im); 
        $x_l = $x_r = $boxarr[0]; 
        $y_t = $y_b = $boxarr[1]; 
        for($i=0;$i<7;$i = $i+2) { 
            $x_l = $boxarr[$i] < $x_l ? $boxarr[$i] : $x_l; 
            $x_r = $boxarr[$i] > $x_r ? $boxarr[$i] : $x_r; 
            $y_t = $boxarr[$i+1] < $y_t ? $boxarr[$i+1] : $y_t; 
            $y_b = $boxarr[$i+1] > $y_b ? $boxarr[$i+1] : $y_b; 
        } 
        $width = $x_r - $x_l; 
        $height = $y_b - $y_t; 
        /*获取精确偏移量*/ 
        $im = $this->create($width*4,$height*4); 
        $tm = hexdec('7fffffff'); 
        imagettftext($im,$size,$angle,$width*2,$height*2,$color,$font,$str); 
        for($i=0;$i<$width*4;$i++) { 
            for($ii=0;$ii<$height*4;$ii++) { 
                if(imagecolorat($im,$i,$ii) != $tm) { 
                    $x_l = $i; 
                    break(2); 
                } 
            } 
        } 
        for($i=0;$i<$height*4;$i++) { 
            for($ii=$x_l;$ii<$width*4;$ii++) { 
                if(imagecolorat($im,$ii,$i) != $tm) { 
                    $y_t = $i; 
                    break(2); 
                } 
            } 
        } 
        for($i=$width*4-1;$i>0;$i--) { 
            for($ii=$y_t;$ii<$height*4;$ii++) { 
                if(imagecolorat($im,$i,$ii) != $tm) { 
                    $x_r = $i; 
                    break(2); 
                } 
            } 
        } 
        for($i=$height*4-1;$i>0;$i--) { 
            for($ii=$x_l;$ii<=$x_r;$ii++) { 
                if(imagecolorat($im,$ii,$i) != $tm) { 
                    $y_b = $i; 
                    break(2); 
                } 
            } 
        } 
        $x_off = $x_l - $width*2; 
        $y_off = $y_b - $height*2; 
        $width = $x_r - $x_l; //精确宽度 
        $height = $y_b - $y_t; //精确高度 
        imagedestroy($im); 
        if(isset($arg['left'])) { 
            $x = (int)$arg['left'] - $x_off; 
        }elseif (isset($arg['right'])){ 
            $x = $w - (int)$arg['right'] - $width - $x_off; 
        }else { 
            $x = ($w - $width)/2 - $x_off; 
        } 
        if(isset($arg['top'])) { 
            $y = (int)$arg['top'] - $y_off + $height; 
        }elseif (isset($arg['bottom'])){ 
            $y = $h - (int)$arg['bottom'] - $y_off; 
        }else { 
            $y = ($h + $height)/2 - $y_off; 
        } 
        imagettftext($this->im,$size,$angle,$x,$y,$color,$font,$str); 
        return $this->im; 
    } 
    /* 
    *合并图片（如图片水影） 
    *@param string/resource $file 图片文件路径或这图片标识符 
    *@param array $arg 字符串相关的参数，为一个关联数组，left 为距左边距离，right为距右边距离，left优先，top为距顶部距离，bottom为距底部距离，top优先；touming为文字透明度 
    */ 
    function merge($file,$arg = array()) { 
        if(is_file($file)) { 
            $imc = $this->create($file); 
        }elseif(gettype($file)=='resource') { 
            $imc = $file; 
        }else { 
            error("没有图片"); 
        } 
        $touming = $arg['touming'] ? (int)$arg['touming'] : 100 ; 
        $w = imagesx($this->im); 
        $h = imagesy($this->im); 
        $width = imagesx($imc); 
        $height = imagesy($imc); 
        if(isset($arg['left'])) { 
            $x = (int)$arg['left']; 
        }elseif (isset($arg['right'])){ 
            $x = $w - (int)$arg['right'] - $width; 
        }else { 
            $x = ($w - $width)/2; 
        } 
        if(isset($arg['top'])) { 
            $y = (int)$arg['top']; 
        }elseif (isset($arg['bottom'])){ 
            $y = $h - $height - $arg['bottom']; 
        }else { 
            $y = ($h - $height)/2; 
        } 
        imagecopymergegray($this->im,$imc,$x,$y,0,0,$width,$height,$touming); 
    } 
    /* 
    *输出图片 
    *@param string $type 
    *@param string $filename 要转存的文件路径 
    *@param int $zhiliang jpeg图片特有的，图像清晰度 
    */ 
    function display($type = null,$filename = null,$zhiliang = null) { 
        if($type == null) { 
            $type = $this->type ? $this->type : 'jpg'; 
        } 
        if(($type == 'jpeg' or $type == 'jpg') and $zhiliang == null) { 
            $type = 'jpeg'; 
            $zhiliang = 100; 
        } 
        if($filename == null) { 
            header('Content-type: image/'.$type); 
        } 
        $displayfunc = 'image'.$type; 
        $displayfunc($this->im,$filename,$zhiliang); 
        imagedestroy($this->im); 
    } 
    function randcolor($a,$b) { 
        $a = $a>255 ? 255 : (int)$a; 
        $a = $a<0 ? 0 : (int)$a; 
        $b = $b>255 ? 255 : (int)$b; 
        $b = $b<0 ? 0 : (int)$b; 
        for($i=0;$i<3;$i++) { 
            $color .= str_pad(dechex(mt_rand($a,$b)), 2, "0", STR_PAD_LEFT); 
        } 
        return $color; 
    } 
} 
/* 
function error($msg,$debug = false) { 
    $err = new Exception($msg); 
    $str = "<pre>\n<span style="color:red" style="color:red">错误:</span>\n".print_r($err->getTrace(),1)."\n</pre>"; 
    if($debug == true) { 
        file_put_contents(date('Y-m-d').".log",$str); 
        return $str; 
    }else{ 
        die($str); 
    } 
} 
*/ 
?>

这是简单的用法实例

$img = new img('a.png'); 
$m = $img->im; 
$im = $img->suolue(100); 
$img->im = $m; 
$img->suolue(300); 
$img->merge($m,array('left'=>0,'top'=>0,'touming'=>60)); 
$img->merge($im,array('right'=>0,'top'=>0,'touming'=>60)); 
$img->merge($im,array('left'=>0,'bottom'=>0,'touming'=>60)); 
$img->merge($im,array('right'=>0,'bottom'=>0,'touming'=>60)); $img->write("春天来了",array('left'=>0,'top'=>0,'size'=>30,'color'=>$img->randcolor(0,180),'angle'=>-45,'font'=>'simfang.ttf','touming'=>80)); 
$img->write("春天来了",array('left'=>0,'bottom'=>0,'size'=>30,'color'=>$img->randcolor(0,180),'angle'=>45,'font'=>'simfang.ttf','touming'=>80)); 
$img->write("春天来了",array('right'=>0,'bottom'=>0,'size'=>30,'color'=>$img->randcolor(0,180),'angle'=>-45,'font'=>'simfang.ttf','touming'=>80)); 
$img->write("春天来了",array('right'=>0,'top'=>0,'size'=>30,'color'=>$img->randcolor(0,180),'angle'=>45,'font'=>'simfang.ttf','touming'=>80)); 
$img->display("gif");