/**
 * 拼接多幅圖片成為一張圖片
 *
 * 引數說明：原圖片為檔案路徑陣列，目的圖片如果留空，則不儲存結果
 *
 * 例子：
 * <code>
 * $ci = new CombineImage(array("D:/Downloads/1.jpg", "D:/Downloads/2.png"), "D:/Downloads/3.png");
 * $ci->combine();
 * $ci->show();
 * </code>
 *
 * @author 張榮傑
 * @version 2012.8.9
 */
class CombineImage {
    /**
     * 原圖地址陣列
     */
 

    private $srcImages;
    /**
     * 每張圖片縮放到這個寬度
     */
    private $width;
    /**
     * 每張圖片縮放到這個高度
     */
    private $height;
    /**
     * 拼接模式，可以選擇水平或垂直
     */
    private $mode;
    /**
     * 水平拼接模式常量
     */
    const COMBINE_MODE_HORIZONTAL = "horizontal";
    /**
     * 垂直拼接模式常量
     */
    const
 
 COMBINE_MODE_VERTICAL = "vertical";
    /**
     * 目標圖片地址
     */
    private $destImage;
    /**
     * 臨時畫布
     */
    private $canvas;
    /**
     * 建構函式，傳入原圖地址陣列和目標圖片地址
     */
    public function __construct($srcImages = '', $desImage = '',
                $width = 410, $height = 410,
                $mode = self::COMBINE_MODE_HORIZONTAL) {
        $this
 
->srcImages = $srcImages;
        $this->destImage = $desImage;
        $this->width = $width;
        $this->height = $height;
        $this->mode = $mode;
        $this->canvas = NULL;
    }
    public function __destruct() {
        if ($this->canvas != NULL) {
            imagedestroy($this->canvas);
        }
    }
    /**
     * 合併圖片
     */
    public function combine() {
        if (empty($this->srcImages)	|| $this->width==0 || $this->height==0) {
            return;
        }
        $this->createCanvas();
        for($i=0; $i<count($this->srcImages); $i++) {
            $srcImage = $this->srcImages[$i];
            $srcImageInfo = getimagesize($srcImage);
            /*echo '<pre/>';
            var_dump($srcImageInfo);
            echo '<br/>=====';*/
            // 如果能夠正確的獲取原圖的基本資訊
            if ($srcImageInfo) {
                $srcWidth = $srcImageInfo[0];
                $srcHeight = $srcImageInfo[1];
                $fileType = $srcImageInfo[2];
                if ($fileType == 2) {
                    // 原圖是 jpg 型別
                    $srcImage = imagecreatefromjpeg($srcImage);
                } else if ($fileType == 3) {
                    // 原圖是 png 型別
                    $srcImage = imagecreatefrompng($srcImage);
                } else if($fileType == 1){
                    // 原圖是 gift 型別
                    $srcImage = imagecreatefromgif($srcImage);
                }else {
                    // 無法識別的型別
                    continue;
                }
                // 計算當前原圖片應該位於畫布的哪個位置
                if ($this->mode == self::COMBINE_MODE_HORIZONTAL) {
                    $destX = $i * ($this->width);//間距
                    $desyY = 0;
                } elseif ($this->mode == self::COMBINE_MODE_VERTICAL) {
                    $destX = 0;
                    $desyY = $i * $this->height;
                }
                imagecopyresampled($this->canvas, $srcImage, $destX, $desyY,
                            0, 0, $this->width, $this->height, $srcWidth, $srcHeight);
            }
        }

        // 如果有指定目標地址，則輸出到檔案
        if ( ! empty($this->destImage)) {
            $this->output();
        }
    }
    /**
     * 輸出結果到瀏覽器
     */
    public function show() {
        if ($this->canvas == NULL) {
            return;
        }
        header("Content-type: image/jpeg");
        imagejpeg($this->canvas);
    }
    /**
     * 私有函式，建立畫布
     */
    private function createCanvas() {
        $totalImage = count($this->srcImages);
        if ($this->mode == self::COMBINE_MODE_HORIZONTAL) {
            $width = $totalImage * $this->width;//間距
            $height = $this->height;
        } else if ($this->mode == self::COMBINE_MODE_VERTICAL) {
            $width = $this->width;
            $height = $totalImage * $this->height;
        }
        $this->canvas = imagecreatetruecolor($width, $height);
        imagealphablending($this->canvas,false);//這裡很重要,意思是不合並顏色,直接用$img影象顏色替換,包括透明色;
       imagesavealpha($this->canvas,true);//這裡很重要,意思是不要丟了$thumb影象的透明色;
        // 使畫布透明
        $white = imagecolorallocate($this->canvas, 255, 255, 255);
//        $bg = imagecolorallocatealpha($this->canvas , 0 , 0 , 0 , 127);
        imagefill($this->canvas, 0, 0, $white);
//        imagefill($this->canvas, 0, 0, $bg);
        imagecolortransparent($this->canvas, $white);
//        imagecolortransparent($this->canvas, $bg);
    }
    /**
     * 私有函式，儲存結果到檔案
     */
    private function output() {
        // 獲取目標檔案的字尾
        $fileType = substr(strrchr($this->destImage, '.'), 1);
        if ($fileType=='jpg' || $fileType=='jpeg') {
            imagejpeg($this->canvas, $this->destImage);
        } else if($fileType=='gif'){
            imagegif($this->canvas,$this->destImage);
        }else {
            // 預設輸出 png 圖片
            imagepng($this->canvas, $this->destImage);
        }
    }
    /**
     * @return the $srcImages
     */
    public function getSrcImages() {
        return $this->srcImages;
    }
    /**
     * @param Array $srcImages
     */
    public function setSrcImages($srcImages) {
        $this->srcImages = $srcImages;
    }
    /**
     * @return the $width
     */
    public function getWidth() {
        return $this->width;
    }
    /**
     * @param int $width
     */
    public function setWidth($width) {
        $this->width = $width;
    }
    /**
     * @return the $height
     */
    public function getHeight() {
        return $this->height;
    }
    /**
     * @param int $height
     */
    public function setHeight($height) {
        $this->height = $height;
    }
    /**
     * @return the $mode
     */
    public function getMode() {
        return $this->mode;
    }
    /**
     * @param const $mode
     */
    public function setMode($mode) {
        $this->mode = $mode;
    }
    /**
     * @return the $destImage
     */
    public function getDestImage() {
        return $this->destImage;
    }
    /**
     * @param String $destImage
     */
    public function setDestImage($destImage) {
        $this->destImage = $destImage;
    }
}
?>