5-1图像类的封装

<?php
/**
 * Image.php
 * 
 * description 图像类
 */

namespace ImoocLib;

require_once 'GDBasic.php';

class Image extends GDBasic
{
    protected $_width;
    protected $_height;
    protected $_im;
    protected $_type;
    protected $_mime;
    protected $_real_path;

    
    public function __construct($file)
    {
        //检查GD库
        self::check();
        $imageInfo = $this->createImageByFile($file);
        $this->_width = $imageInfo['width'];
        $this->_height = $imageInfo['height'];
        $this->_im = $imageInfo['im'];
        $this->_type = $imageInfo['type'];
        $this->_real_path = $imageInfo['real_path'];
        $this->_mime = $imageInfo['mime'];
    }


    /**
     * 根据文件创建图像
     * @param $file
     * @return array
     * @throws Exception
     */
    public function createImageByFile($file)
    {
        //检查文件是否存在
        if(!file_exists($file))
        {
            throw new Exception('file is not exits');
        }

        //获取图像信息
        $imageInfo = getimagesize($file);
        $realPath = realpath($file);
        if(!$imageInfo)
        {
            throw new Exception('file is not image file');
        }

        switch($imageInfo[2])
        {
            case IMAGETYPE_GIF:
                $im = imagecreatefromgif($file);
                break;
            case IMAGETYPE_JPEG:
                $im = imagecreatefromjpeg($file);
                break;
            case IMAGETYPE_PNG:
                $im = imagecreatefrompng($file);
                break;
            default:
                throw  new Exception('image file must be png,jpeg,gif');
        }

        return array(
            'width'     => $imageInfo[0],
            'height'    => $imageInfo[1],
            'type'      => $imageInfo[2],
            'mime'      => $imageInfo['mime'],
            'im'        => $im,
            'real_path' => $realPath,
        );

    }

    /**
     * 缩略图
     * @param  int $width 缩略图高度
     * @param  int $height 缩略图宽度
     * @return $this
     * @throws Exception
     */
    public function resize($width, $height)
    {
        if(!is_numeric($width) || !is_numeric($height))
        {
            throw new Exception('image width or height must be number');
        }
        //根据传参的宽高获取最终图像的宽高
        $srcW = $this->_width;
        $srcH = $this->_height;

        if($width <= 0 || $height <= 0)
        {
            $desW = $srcW;//缩略图高度
            $desH = $srcH;//缩略图宽度
        }
        else
        {
            $srcP = $srcW / $srcH;//宽高比
            $desP = $width / $height;

            if($width > $srcW)
            {
                if($height > $srcH)
                {
                    $desW = $srcW;
                    $desH = $srcH;
                }
                else
                {
                    $desH = $height;
                    $desW = round($desH * $srcP);
                }
            }
            else
            {
                if($desP > $srcP)
                {
                    $desW = $width;
                    $desH = round($desW / $srcP);
                }
                else
                {
                    $desH = $height;
                    $desW = round($desH * $srcP);
                }
            }
        }

        //PHP版本小于5.5
        if(version_compare(PHP_VERSION, '5.5.0', '<'))
        {
            $desIm = imagecreatetruecolor($desW, $desH);
            if(imagecopyresampled($desIm, $this->_im, 0, 0, 0, 0, $desW, $desH, $srcW, $srcH))
            {
                imagedestroy($this->_im);
                $this->_im = $desIm;
                $this->_width = imagesx($this->_im);
                $this->_height = imagesy($this->_im);
            }
        }
        else
        {
            if($desIm = imagescale($this->_im, $desW, $desH))
            {
                $this->_im = $desIm;
                $this->_width = imagesx($this->_im);
                $this->_height = imagesy($this->_im);
            }

        }

        return $this;
    }


    /**
     * 根据百分比生成缩略图
     * @param int $percent 1-100
     * @return Image
     * @throws Exception
     */
    public function resizeByPercent($percent)
    {
        if(intval($percent) <= 0)
        {
            throw new Exception('percent must be gt 0');
        }

        $percent = intval($percent) > 100 ? 100 : intval($percent);

        $percent = $percent / 100;

        $desW = $this->_width * $percent;
        $desH = $this->_height * $percent;
        return $this->resize($desW, $desH);
    }


    /**
     * 图像旋转
     * @param $degree
     * @return $this
     */
    public function rotate($degree)
    {
        $degree = 360 - intval($degree);
        $back = imagecolorallocatealpha($this->_im,0,0,0,127);
        $im = imagerotate($this->_im,$degree,$back,1);
        imagesavealpha($im,true);
        imagedestroy($this->_im);
        $this->_im = $im;
        $this->_width = imagesx($this->_im);
        $this->_height = imagesy($this->_im);
        return $this;
    }


    /**
     * 生成水印
     * @param file $water 水印图片
     * @param int $pct   透明度
     * @return $this
     */
    public function waterMask($water ='',$pct = 60 )
    {
        //根据水印图像文件生成图像资源
        $waterInfo = $this->createImageByFile($water);
        imagecopymerge();
        //销毁$this->_im
        $this->_im = $waterInfo['im'];
        $this->_width = imagesx($this->_im);
        $this->_height = imagesy($this->_im);
        return $this;

    }



    /**
     * 图片输出
     * @return bool
     */
    public function show()
    {
        header('Content-Type:' . $this->_mime);
        if($this->_type == 1)
        {
            imagegif($this->_im);
            return true;
        }

        if($this->_type == 2)
        {
            imagejpeg($this->_im, null, 80);
            return true;
        }

        if($this->_type == 3)
        {
            imagepng($this->_im);
            return true;
        }
    }

    /**
     * 保存图像文件
     * @param $file
     * @param null $quality
     * @return bool
     * @throws Exception
     */
    public function save($file, $quality = null)
    {
        //获取保存目的文件的扩展名
        $ext = pathinfo($file, PATHINFO_EXTENSION);
        $ext = strtolower($ext);
        if(!$ext || !in_array($ext, array('jpg', 'jpeg', 'gif', 'png')))
        {
            throw new Exception('image save file must be jpg ,png,gif');
        }

        if($ext === 'gif')
        {
            imagegif($this->_im, $file);
            return true;
        }
        if($ext === 'jpeg' || $ext === 'jpg')
        {
            if($quality > 0)
            {
                if($quality < 1)
                {
                    $quality = 1;
                }
                if($quality > 100)
                {
                    $quality = 100;
                }

                imagejpeg($this->_im, $file, $quality);
            }
            else
            {
                imagejpeg($this->_im, $file);
            }
            return true;
        }

        if($ext === 'png')
        {
            imagepng($this->_im, $file);
            return true;
        }

    }
}

调用

require_once './lib/Image.php';

$image = new ImoocLibImage('../image/b.png');
//$image->resize(400,200)->save('../image/b_400_200.png');
$image->resizeByPercent(50)->rotate(1800)->show();