thinkphp6 水印

/**
 * 生成宣传海报
 * @param array  参数,包括图片和文字
 * @param string  $filename 生成海报文件名,不传此参数则不生成文件,直接输出图片
 * @return [type] [description]
 */
function createPoster($config = array() , $filename = "") {
    //如果要看报什么错，可以先注释调这个header
    //if(empty($filename)) header("content-type: image/png");
    if (empty($filename)) header("content-type: image/png");
    $imageDefault = array(
        'left' => 0,
        'top' => 0,
        'right' => 0,
        'bottom' => 0,
        'width' => 100,
        'height' => 100,
        'opacity' => 100
    );
    $textDefault = array(
        'text' => '',
        'left' => 0,
        'top' => 0,
        'fontSize' => 32, //字号
        'fontColor' => '255,255,255', //字体颜色
        'angle' => 0,
    );
    $background = $config['background']; //海报最底层得背景
    //背景方法
    $backgroundInfo = getimagesize($background);
    $backgroundFun = 'imagecreatefrom' . image_type_to_extension($backgroundInfo[2], false);
    $background = $backgroundFun($background);
    $backgroundWidth = imagesx($background); //背景宽度
    $backgroundHeight = imagesy($background); //背景高度
    $imageRes = imageCreatetruecolor($backgroundWidth, $backgroundHeight);
    $color = imagecolorallocate($imageRes, 0, 0, 0);
    imagefill($imageRes, 0, 0, $color);
    imagecopyresampled($imageRes, $background, 0, 0, 0, 0, imagesx($background) , imagesy($background) , imagesx($background) , imagesy($background));
    //处理了图片
    if (!empty($config['image'])) {
        foreach ($config['image'] as $key => $val) {
            $val = array_merge($imageDefault, $val);
            $info = getimagesize($val['url']);
            $function = 'imagecreatefrom' . image_type_to_extension($info[2], false);
            if ($val['stream']) { //如果传的是字符串图像流
                $info = getimagesizefromstring($val['url']);
                $function = 'imagecreatefromstring';
            }
            $res = $function($val['url']);
            $resWidth = $info[0];
            $resHeight = $info[1];
            
            
             //判断是否把图片切割成圆形
            if ($val['is_yuan']) {
                $w = $info[0];
                $h = $info[1];
                $w = min($w, $h);
                $h = $w;
                $yuan_img = imagecreatetruecolor($w, $h);
                //这一句一定要有
                imagesavealpha($yuan_img, true);
                //拾取一个完全透明的颜色,最后一个参数127为全透明
                $bg = imagecolorallocatealpha($yuan_img, 255, 255, 255, 127);
                imagefill($yuan_img, 0, 0, $bg);
                $r = $w / 2; //圆半径
                $y_x = $r; //圆心X坐标
                $y_y = $r; //圆心Y坐标
                for ($x = 0; $x < $w; $x++) {
                    for ($y = 0; $y < $h; $y++) {
                        $rgbColor = imagecolorat($res, $x, $y);
                        if (((($x - $r) * ($x - $r) + ($y - $r) * ($y - $r)) < ($r * $r))) {
                            imagesetpixel($yuan_img, $x, $y, $rgbColor);
                        }
                    }
                }
                imagecopyresampled($imageRes, $yuan_img, $val['left'], $val['top'], 0, 0, $val['width'], $val['height'], $w, $h);
            }
            else {
                //建立画板 ，缩放图片至指定尺寸
                $canvas = imagecreatetruecolor($val['width'], $val['height']);
                imagefill($canvas, 0, 0, $color);
                //如果是透明的gif或png做透明处理
                $ext = pathinfo($val['url']);
                if (array_key_exists('extension',$ext)) {
                    if ($ext['extension'] == 'gif' || $ext['extension'] == 'png') {
                        imageColorTransparent($canvas, $color); //颜色透明
                         
                    }
                }
                //关键函数，参数（目标资源，源，目标资源的开始坐标x,y, 源资源的开始坐标x,y,目标资源的宽高w,h,源资源的宽高w,h）
                imagecopyresampled($canvas, $res, 0, 0, 0, 0, $val['width'], $val['height'], $resWidth, $resHeight);
                //$val['left'] = $val['left']<0?$backgroundWidth- abs($val['left']) - $val['width']:$val['left'];
                //如果left小于-1我这做成了计算让其水平居中
                if ($val['left'] < 0) {
                    $val['left'] = ceil($backgroundWidth - $val['width']) / 2;
                }
                $val['top'] = $val['top'] < 0 ? $backgroundHeight - abs($val['top']) - $val['height'] : $val['top'];
                //放置图像
                imagecopymerge($imageRes, $canvas, $val['left'], $val['top'], $val['right'], $val['bottom'], $val['width'], $val['height'], $val['opacity']); //左，上，右，下，宽度，高度，透明度
                
            }
            
            
           
             
        }
    }
    //处理文字
    if (!empty($config['text'])) {
        foreach ($config['text'] as $key => $val) {
            $val = array_merge($textDefault, $val);
            list($R, $G, $B) = explode(',', $val['fontColor']);
            $fontColor = imagecolorallocate($imageRes, $R, $G, $B);
            //$val['left'] = $val['left']<0?$backgroundWidth- abs($val['left']):$val['left'];
            //如果left小于-1我这做成了计算让其水平居中
            if ($val['left'] < 0) {
                $fontBox = imagettfbbox($val['fontSize'], 0, $val['fontPath'], $val['text']); //文字水平居中实质
                $val['left'] = ceil(($backgroundWidth - $fontBox[2]) / 2); //计算文字的水平位置
                 
            }
            $val['top'] = $val['top'] < 0 ? $backgroundHeight - abs($val['top']) : $val['top'];
            imagettftext($imageRes, $val['fontSize'], $val['angle'], $val['left'], $val['top'], $fontColor, $val['fontPath'], $val['text']);
        }
    }
    
    //处理文字
    if (!empty($config['position'])) {
        foreach ($config['position'] as $key => $val) {
            $val = array_merge($textDefault, $val);
            list($R, $G, $B) = explode(',', $val['fontColor']);
            $fontColor = imagecolorallocate($imageRes, $R, $G, $B);
            //$val['left'] = $val['left']<0?$backgroundWidth- abs($val['left']):$val['left'];
            //如果left小于-1我这做成了计算让其水平居中
            if ($val['left'] < 0) {
                $fontBox = imagettfbbox($val['fontSize'], 0, $val['fontPath'], $val['text']); //文字水平居中实质
                $val['left'] = ceil(($backgroundWidth - $fontBox[2]) / 2); //计算文字的水平位置
                 
            }
            $val['top'] = $val['top'] < 0 ? $backgroundHeight - abs($val['top']) : $val['top'];
            imagettftext($imageRes, $val['fontSize'], $val['angle'], $val['left'], $val['top'], $fontColor, $val['fontPath'], $val['text']);
        }
    }
    
    //生成图片
    if (!empty($filename)) {
        $res = imagejpeg($imageRes, $filename, 90); //保存到本地
        imagedestroy($imageRes);
        if (!$res) return false;
        return $filename;
    } else {
        header("Content-type:image/png");
        imagejpeg($imageRes); //在浏览器上显示
        imagedestroy($imageRes);
    }
}