php方便水印和缩略图的图形类

/*
*@author 夜无眠 27262681@qq.com
*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 = "

\n错误:\n".print_r($err->getTrace(),1)."\n

代码如下:

$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");