php 合成 png 图片

$config = array(
  'image'=>array(
    array(
      'url'=>'1.png',     //二维码资源
      'stream'=>0,
      'left'=>116,
      'top'=>-216,
      'right'=>0,
      'bottom'=>0,
      'width'=>178,
      'height'=>178,
      'opacity'=>100
    )
  ),
  'background'=>'bg1.jpg'          //背景图
);
$filename = time().'.jpg';
//echo createPoster($config,$filename);
echo createPoster($config);



    /**
     * 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");
        }
        $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);
        imagealphablending($imageRes, true);//关闭混合模式，以便透明颜色能覆盖原画板
        imagefill($imageRes, 0, 0, $color);
        imagesavealpha($imageRes, true);//设置保存PNG时保留透明通道信息

        imageColorTransparent($imageRes, $color);  //颜色透明
        imagecopyresampled($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']);
				$color = imagecolorallocate($imageRes, 255, 255, 255);
				imagecolortransparent($canvas,$color);
                imagefill($canvas, 0, 0, $color);
                //关键函数，参数（目标资源，源，目标资源的开始坐标x,y, 源资源的开始坐标x,y,目标资源的宽高w,h,源资源的宽高w,h）
                imagecopyresampled($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'];
                $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'];
                $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 $filename;
        } else {
            imagejpeg($imageRes);     //在浏览器上显示
            imagedestroy($imageRes);
        }
    }