php生成h5

对于h5中生成海报大家都不陌生 最常见的方法是前端生成 用html2canvas  但是弊端就是画质太差 网上很多方法 但是依然不是很管用  最近做的h5中 用了php来生成 画质简直美得不行 分享给大家

/**
 * 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];
            //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'], $val['text']);
        }
    }
    //生成图片
    if (!empty($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);
    }
}
$config = array(
  'text'=>array(
    array(
      'text'=>'昵称',
      'left'=>182,
      'top'=>105,
      'fontPath'=>'qrcode/simhei.ttf',     //字体文件
      'fontSize'=>18,             //字号
      'fontColor'=>'255,0,0',       //字体颜色
      'angle'=>0,
    )
  ),
  'image'=>array(
    array(
      'url'=>'qrcode/qrcode.png',       //图片资源路径
      'left'=>130,
      'top'=>-140,
      'stream'=>0,             //图片资源是否是字符串图像流
      'right'=>0,
      'bottom'=>0,
      'width'=>150,
      'height'=>150,
      'opacity'=>100
    ),
    array(
      'url'=>'https://wx.qlogo.cn/mmopen/vi_32/DYAIOgq83eofD96opK97RXwM179G9IJytIgqXod8jH9icFf6Cia6sJ0fxeILLMLf0dVviaF3SnibxtrFaVO3c8Ria2w/0',
      'left'=>120,
      'top'=>70,
      'right'=>0,
      'stream'=>0,
      'bottom'=>0,
      'width'=>55,
      'height'=>55,
      'opacity'=>100
    ),
  ),
  'background'=>'qrcode/bjim.jpg',
);
$filename = 'qrcode/'.time().'.jpg';
//echo createPoster($config,$filename);
echo createPoster($config);