<?php 
/**
 * PHP Gmagick的使用类
 * 
 * @example
 * <pre>
 *     $gm = new Util_Image_Gmagick('test.jpg', false, 'jpg');
 *     1. 生成缩略图. 处理后,图片保持完整
 *     $gm->thumbnail(100, 100)->compress()->save('test1.jpg');
 *     2. 图片贴在白色背景上. 处理后,图片保持完整 (对应原来切图模式: 2)
 *     $gm->paste(100, 100)->compress()->save('test2.jpg');
 *     3. 剪切图片. 处理后,图片不完整 (对应原来切图模式: 3)
 *     $gm->crop(100, 100)->compress()->save('test3.jpg');
 *     4. 缩放尺寸. 处理后,图片保持完整  (对应原来切图模式: 4)
 *     $gm->resize(100, 100)->compress()->save('test4.jpg');
 *     5. 缩略并从中间剪切. 处理后,图片不完整 (对应原来切图模式: 5)
 *     $gm->autoCrop(100, 100)->compress()->save('test5.jpg');
 *     6. 自定义的切图. 处理后,图片的完整性不固定 (根据yoho.cn业务需求)
 *     $gm->customCrop(100, 100)->compress()->save('test6.jpg');
 * </pre>
 * 
 * @name Util_Image_Gmagick
 * @package util/image
 * @copyright yoho.inc
 * @version 1.3 (2013-09-16 09:11:27)
 * @author fei.hong <hf@yoho.cn>
 * @since 1.0 (2012-11-20 16:33:29)
 * @see http://docs.php.net/manual/zh/book.gmagick.php
 */
class Util_Image_Gmagick implements Util_Image_Interface
{
    /**
     * @var object (Gmagick)
     */
    private $_handle;
    
    /**
     * @var integer (宽度)
     */
    private $_width;
    
    /**
     * @var integer (高度)
     */
    private $_height;
    
    /**
     * @var object (FastDFSClient)
     */
    private $_fastdfsHandle;
    
    /**
     * @var boolean (fastdfs状态)
     */
    private $_fastdfsStatus = false;
    
    /**
     * @var boolean (静态化图片的开关)
     * @since 1.2
     */
    private $_flatten = false;
    
    /**
     * @var string (格式)
     * @since 1.2
     */
    private $_format;
    
    /**
     * 构造函数
     * 
     * @param string $filename (源图片路径)
     * @param boolean $fastdfsStatus (是否启用fastDFS)
     */
    public function __construct($filename, $fastdfsStatus = false)
    {
    	if (false !== $fastdfsStatus)
    	{
    		$this->_fastdfsStatus = $fastdfsStatus;
    		$this->_fastdfsHandle = new MyFastDFSClient();
    		$this->_handle = new Gmagick();
    		$this->_handle->readImageBlob($this->_fastdfsHandle->download_file_to_buff($filename));
    	}
    	else
    	{
    		$this->_handle = new Gmagick($filename);
    	}
    	
        $this->_width = $this->_handle->getimagewidth();
        $this->_height = $this->_handle->getimageheight();
        $this->_format = strtolower($this->_handle->getimageformat());
    }
    
    /**
     * 析构函数
     */
    public function __destruct()
    {
    	if (null !== $this->_handle)
    	{
    		$this->_handle->clear();
    		$this->_handle->destroy();
    		$this->_handle = null;
    	}
    	
    	if (false !== $this->_fastdfsStatus)
    	{
    	    $this->_fastdfsHandle->close();
    	    $this->_fastdfsHandle = null;
    	}
    }
    
    /**
     * 缩略图
     * 
     * 更改图像大小为指定的尺寸, 并清除图片的所有相关属性信息. (体积小)
     * 
     * @param integer $w (缩略宽度, 当数值<=0或>=9999时表示按高度等比例缩放)
     * @param integer $h (缩略高度, 当数值<=0或>=9999时表示按宽度等比例缩放)
     * @param boolean $fit (控制是否按照宽高的最大值等比例缩放)
     * @return object
     */
    public function thumbnail($w, $h, $fit = true)
    {
    	$this->compareSize($w, $h, __FUNCTION__);
    	
    	if ($h === 0 || $w === 0)
    	{
    		$fit = false;
    	}
    	
    	if (false === $this->_flatten && $this->_format === 'gif')
    	{
    	    // 获取GIF图片中的图片张数，即图片索引值
    	    $index = $this->_handle->getImageIndex(); 
    	    
    	    for ($i = 0; $i < $index; $i ++) 
    	    {
    	        $this->_handle->setImageIndex($i);
    	        $this->_handle->scaleImage($w, $h, $fit);
    	        $this->_handle->thumbnailImage($w, $h, $fit);
    	    }
    	}
    	else
    	{
    	    $this->_handle->scaleImage($w, $h, $fit);
    	    $this->_handle->thumbnailImage($w, $h, $fit);
    	}
        
    	return $this;
    }
    
    /**
     * 缩放图片尺寸
     * 
     * 缩放图像到所需的尺寸(宽高), 可以带上滤镜效果.
     * 
     * 滤镜使用 @see http://www.php.net/manual/zh/gmagick.constants.php
     * 
     * @param integer $w (缩放宽度)
     * @param integer $h (缩放高度)
     * @param boolean $fit (控制是否按照宽高的最大值等比例缩放)
     * @return object
     */
    public function resize($w, $h, $fit = true)
    {
    	$this->compareSize($w, $h, __FUNCTION__);
    	
    	if (false === $this->_flatten && $this->_format === 'gif')
    	{
    	    // 获取GIF图片中的图片张数，即图片索引值
    	    $index = $this->_handle->getImageIndex();
    	    	
    	    for ($i = 0; $i < $index; $i++)
    	    {
    	        // 定位到当前图片
    	        $this->_handle->setImageIndex($i);
    	        $this->_handle->resizeImage($w, $h, Gmagick::FILTER_CATROM, 1, $fit);
    	    }
    	}
    	else
    	{
            $this->_handle->resizeImage($w, $h, Gmagick::FILTER_CATROM, 1, $fit);
    	}
        
        return $this;
    }
    
    /**
     * 背景贴图
     *
     * 生成一下指定背景的画布图, 再将图片复合贴在画布背景图的指定位置上.
     *
     * @param integer $w (需求宽度)
     * @param integer $h (需求高度)
     * @param string  $bg (背景图片)
     * @return object
     */
    public function paste($w, $h, $bg = '#FFFFFF')
    {
    	$this->compareSize($w, $h, __FUNCTION__);
    
    	// 如里需求图片的尺寸小于原图片的尺寸, 则生成缩略图
    	if ($w <= $this->_width && $h <= $this->_height)
    	{
    	    if (false === $this->_flatten && $this->_format === 'gif')
    	    {
    	        // 获取GIF图片中的图片张数，即图片索引值
    	        $index = $this->_handle->getImageIndex();
    	        	
    	        for ($i = 0; $i < $index; $i++)
    	        {
    	            // 定位到当前图片
    	            $this->_handle->setImageIndex($i);
    	             
                    $this->_handle->resizeImage($w, $h, Gmagick::FILTER_CATROM, 1, true);
    	        }
    	    }
    	    else
    	    {
    		    $this->_handle->resizeImage($w, $h, Gmagick::FILTER_CATROM, 1, true);
    	    }
    		 
    		return $this;
    	}
    
    	if ($w < $this->_width || $h < $this->_height)
    	{
    		// 缩放图片
    		$this->_handle->scaleImage($w, $h, true);
    
    		// 缩放宽高
    		$sw = $this->_handle->getImageWidth();
    		$sh = $this->_handle->getImageHeight();
    
    		// 计算位置
    		$x = ($w - $sw) / 2;
    		$y = ($h - $sh) / 2;
    	}
    	else
    	{
    		$x = ($w - $this->_width) / 2;
    		$y = ($h - $this->_height) / 2;
    	}
    
    	// 新建背景图层
    	$canvas = new Gmagick();
    	$canvas->newImage($w, $h, $bg, 'JPEG');
    
    	// 将图片贴在背景图层上
    	$this->_handle = $canvas->compositeImage($this->_handle, Gmagick::COMPOSITE_OVER, $x, $y);
    
    	return $this;
    }

    /**
     * 剪切图片
     *
     * 提取图像的一个指定区域. 默认是从原图片的左上角坐标(0,0)到($w,$h)的这个区域.
     *
     * @param integer $w (剪切宽度)
     * @param integer $h (剪切高度)
     * @param integer $x (坐标X轴位置)
     * @param integer $y (坐标Y轴位置)
     * @return object
     */
    public function crop($w, $h, $x = 0, $y = 0)
    {
    	$this->compareSize($w, $h, __FUNCTION__);
    	
    	if (false === $this->_flatten && $this->_format === 'gif')
    	{
    	    // 获取GIF图片中的图片张数，即图片索引值
    	    $index = $this->_handle->getImageIndex();
    	
    	    for ($i = 0; $i < $index; $i++)
    	    {
    	        $this->_handle->setImageIndex($i);
                $this->_handle->cropImage($w, $h, $x, $y);
    	    }
    	}
    	else
    	{
            $this->_handle->cropImage($w, $h, $x, $y);
    	}

    	return $this;
    }
    
    /**
     * 自动切图
     *
     * 先缩放图像, 再从中心指定的区域剪切图片, 创建一个固定宽度和高度的缩略图.
     *
     * @param integer $w (宽度)
     * @param integer $h (高度)
     * @return object
     */
    public function autoCrop($w, $h)
    {
    	$this->compareSize($w, $h, __FUNCTION__);
    	
    	if (false === $this->_flatten && $this->_format === 'gif')
    	{
    	    // 获取GIF图片中的图片张数，即图片索引值
    	    $index = $this->_handle->getImageIndex();
    	     
    	    for ($i = 0; $i < $index; $i++)
    	    {
        	    $this->_handle->setImageIndex($i);
        	    $this->_handle->cropThumbnailImage($w, $h);
    	    }
    	}
    	else
    	{
    	    $this->_handle->cropThumbnailImage($w, $h);
    	}
    	 
    	return $this;
    }
    
    /**
     * [yoho.cn]自定义切图
     *
     * @param integer $w (剪切宽度, 当数值<=0或>=9999表示最大宽度)
     * @param integer $h (剪切高度, 当数值<=0或>=9999表示最大高度)
     * @return object
     * @since 1.1
     */
    public function customCrop($w, $h)
    {
    	if ($w >= $this->_width && $h >= $this->_height)
    	{
    		return $this->paste($w, $h);
    	}
    		
    	$this->compareSize($w, $h, __FUNCTION__);
    	
    	// 获取自定义的缩放比例
    	list($sw, $sh) = $this->getScale($w, $h);
    		
        // 水平居中剪切
        if ($sw > $w && $this->_width >= $this->_height) 
    	{
    	    if (false === $this->_flatten && $this->_format === 'gif')
    	    {
    	        // 获取GIF图片中的图片张数，即图片索引值
    	        $index = $this->_handle->getImageIndex();
    	    
    	        for ($i = 0; $i < $index; $i++)
    	        {
        	        $this->_handle->setImageIndex($i);
                    $this->_handle->resizeImage($sw, $sh, Gmagick::FILTER_CATROM, 1, false);
                    $this->_handle->cropImage($w, $h, ($sw - $w) / 2, 0);
    	        }
            }
            else
            {
                $this->_handle->resizeImage($sw, $sh, Gmagick::FILTER_CATROM, 1, false);
                $this->_handle->cropImage($w, $h, ($sw - $w) / 2, 0);
            }
    	}
    	// 垂直上下剪切
    	elseif ($sh > $h)
    	{
    	    if (false === $this->_flatten && $this->_format === 'gif')
    	    {
    	        // 获取GIF图片中的图片张数，即图片索引值
    	        $index = $this->_handle->getImageIndex();
    	        	
    	        for ($i = 0; $i < $index; $i++)
    	        {
        	        $this->_handle->setImageIndex($i);
            		$this->_handle->resizeImage($sw, $sh, Gmagick::FILTER_CATROM, 1, false);
            		$this->_handle->cropImage($w, $h, 0, 0);
    	        }
	        }
	        else
	        {
	            $this->_handle->resizeImage($sw, $sh, Gmagick::FILTER_CATROM, 1, false);
	            $this->_handle->cropImage($w, $h, 0, 0);
	        }
    	}
    	// 白色背景贴图
    	else
    	{
    		$this->paste($w, $h);
    	}

    	return $this;
    }
    
    /**
     * [yoho.cn] 自定义的活动瀑布流的切图
     * 
     * @param integer $w (剪切宽度)
     * @param integer $h (剪切高度)
     * @return object
     * @since 1.3
     * @see http://wiki.yoho.cn/#789-zh
     */
    public function waterfallCrop($w, $h)
    {
        if (false === $this->_flatten && $this->_format === 'gif')
        {
            $thumbHeight = 0;
            // 获取GIF图片中的图片张数，即图片索引值
            $index = $this->_handle->getImageIndex();
            
            for ($i = 0; $i < $index; $i++)
            {
                $this->_handle->setImageIndex($i);
                $this->_handle->thumbnailImage($w, 0, false);
                
                $thumbHeight = $this->_handle->getImageHeight();
                if ($thumbHeight > $h)
                {
                    $this->_handle->cropImage($w, $h, 0, 0);
                }
            }
        }
        else
        {
        	$this->_handle->thumbnailImage($w, 0, false);
        	
        	$thumbHeight = $this->_handle->getImageHeight();
        	if ($thumbHeight > $h)
        	{
        		$this->_handle->cropImage($w, $h, 0, 0);
        	}
        }
        
        return $this;
    }
    
    /**
     * 拼合图片
     * 
     * 作用是将多个图层的图片转变成单一静态化的图片
     *
     * @return object
     * @since 1.1
     */
    public function flatten()
    {
        $this->_flatten = true;
        
    	// 如果: 图片有上一张或下一张图层(存在多张图片如gif动画)
    	if ($this->_format === 'gif' && ($this->_handle->hasNextImage() || $this->_handle->hasPreviousImage()))
    	{
    		/**
    		 * @see http://pecl.php.net/bugs/bug.php?id=22435
    		 */
    		if (method_exists($this->_handle, 'flattenImages'))
    		{
    			$this->_handle = $this->_handle->flattenImages();
    		}
    	}

    	return $this;
    }
    
    /**
     * 压缩图片处理
     * 
     * @param integer $quality (图片的质量)
     * @return object
     */
    public function compress($quality = 90) 
    {
        // 转换色彩CMYK为RGB
        $cs = $this->_handle->getImageColorSpace();
		if ($cs == Gmagick::COLORSPACE_CMYK) 
		{ 
			$this->_handle->setImageColorSpace(Gmagick::COLORSPACE_SRGB); 
		}
		
		$this->_handle->setImageFormat('JPEG');

		// 除去图像的exif档案信息
		$this->_handle->stripImage();

		// Gmagick设置生成图片质量的方法，Gmagick默认生成的图片质量有点差。
		// 这里设置质量为90, 注意设置质量为90以上的(包括90)可能会导致生成后的图片所占的空间比原图还要大，
		// 还要注意在write()的时候再设置这个压缩质量，不要在把图片经过各种处理之前设置这个值，
		// 这样write的时候质量就不生效了，生成的图片可以用picasa等软件来查看质量。
		// 注意: 这是Graphicsmagick1.3.7以上才支持的方法
		$this->_handle->setCompressionQuality($quality); 
		
		return $this;
    }
    
    /**
     * 保存图片
     * 
     * @param mixed $filename (指定的文件 | null 源文件)
     * @return void
     */
    public function save($filename = null) 
    {
    	if ($this->_fastdfsStatus)
    	{
    		$this->_fastdfsHandle->delete_file($filename);
    		$this->_fastdfsHandle->upload_by_filebuff($filename, $this->_handle->getImageBlob());
    	}
    	else
    	{
    		$this->_handle->write($filename);
    	}
    }
    
    /**
     * 显示图片
     * 
     * @return string
     * @since 1.1
     */
    public function show()
    {
    	header('Content-Type: ' . $this->getMimeType($this->_format));
    	
    	echo $this->_handle->getImageBlob();
    }
    
    /**
     * 获取图片文件的格式
     *
     * @return string
     * @since 1.1
     */
    public function getFormat()
    {
        return $this->_format;
    }
    
    /**
     * 获取缩放的比例 (根据实际业务需求)
     *
     * @param integer $w (缩放宽度--数值<=0或>=9999:最大宽度)
     * @param integer $h (缩放高度--数值<=0或>=9999:最大高度)
     * @return array (缩放宽度, 缩放高度)
     * @since 1.1
     */
    private function getScale($w, $h)
    {
    	// 默认缩放的比例
    	$sw = $w; $sh = $h;
    
    	// 原图与缩略图的宽高比例
    	$widthRate = $this->_width / $w;
    	$heightRate = $this->_height / $h;
    	// 计算缩放的宽高值
    	if ($widthRate > 1 || $heightRate > 1)
    	{
    		if ($widthRate > $heightRate)
    		{
    			$sw = $this->_width / $heightRate;
    		}
    		else
    		{
    			$sh = $this->_height / $widthRate;
    		}
    	}
    
    	return array($sw, $sh);
    }
    
    /**
     * 获取图片的MIME类型
     * 
     * @param string $format (图片格式)
     * @return string
     */
    private function getMimeType($format)
    {
    	$mineType = 'image/jpeg';
    	
        switch ($format)
        {
            case 'jpeg':
            case 'jpg':
                $mineType = 'image/jpeg';
                break;
            case 'gif':
                $mineType = 'image/gif';
                break;
            case 'png':
                $mineType = 'image/png';
                break;
            case 'bmp':
                $mineType = 'image/bmp';
                break;
            case 'xbm':
                $mineType = 'image/xbm';
                break;
            case 'wbmp':
                $mineType = 'image/vnd.wap.wbmp';
                break;
        }
        
        return $mineType;
    }
    
    /**
     * 比较原图宽高与需求宽高 (根据实际业务需求)
     *
     * 比较过程中可能会改变需求的宽和高($w和$h)
     *
     * @param integer $w (需求的宽度)
     * @param integer $h (需求的高度)
     * @param string $func (方法名称)
     * @return void
     * @since 1.2
     */
    private function compareSize(&$w, &$h, $func)
    {
    	switch ($func)
    	{
    		case 'thumbnail':
    			($w >= 9999) ? $w = 0 : ($w > $this->_width ? $w = $this->_width : true);
    			($h >= 9999) ? $h = 0 : ($h > $this->_height ? $h = $this->_height : true);
    			break;
    		case 'resize':
    		case 'crop':
    		case 'autoCrop':
    			($w > $this->_width) ? $w = $this->_width : true;
    			($h > $this->_height) ? $h = $this->_height : true;
    			break;
    		case 'customCrop':
    		case 'paste':
    			($w >= 9999 || $w <= 0) ? $w = $this->_width : true;
    			($h >= 9999 || $h <= 0) ? $h = $this->_height : true;
    			break;
    	}
    }
    
}