From 4e668ad6e34dda6d09ef2ca4d3236c65e398e3be Mon Sep 17 00:00:00 2001
From: banditsmile <banditsmile@qq.com>
Date: Fri, 15 Mar 2019 17:09:52 +0800
Subject: [PATCH] =?UTF-8?q?=E5=8E=8B=E7=BC=A9=E5=9B=BE=E6=9B=BF=E4=BB=A3?=
 =?UTF-8?q?=E6=96=B9=E6=A1=88?=
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---
 application/libraries/Image.php | 167 ++++++++++++++++++++++++++++----
 1 file changed, 149 insertions(+), 18 deletions(-)

diff --git a/application/libraries/Image.php b/application/libraries/Image.php
index 23f283a..d500721 100644
--- a/application/libraries/Image.php
+++ b/application/libraries/Image.php
@@ -6,40 +6,171 @@ class Image{
         public function thumbnail($source,$width,$height){
             //获取缩略图名称
             $source = str_replace("\\","/",$source);
-            $imgarr = explode("/",$source);
             //获取图片信息
             $imginfo = getimagesize($source);
             //图片宽
             $img_w = $imginfo[0];
             //图片高
             $img_h = $imginfo[1];
-            //获取源文件名
-            $filename = end($imgarr);
-            $imgname = explode(".",$filename);
-            //缩略图名称
-            $thumbnail_name = $imgname[0].'_thumb'.'.'.$imgname[1];
-            
-            //获取文件路径
-            $dirname = dirname($source);    //获取的路径最后没有/
+
             //缩略图完整路径
-            $thumbnail_full = $dirname.'/'.$thumbnail_name;
-            $image = new Imagick($source);
+            $thumbnail_full = $this->thumbnailPath($source);
+
+            //原图宽高小于缩略图
+            if(($img_w <= $width) && ($img_h <= $height)){
+                return copy($source, $thumbnail_full);
+            }
+
+            //计算目标图片尺寸，防止挤压变形
+            $dstSize = $this->dstSize($img_w, $img_h, $width, $height);
+            return $this->gdResize($source, $thumbnail_full, $dstSize['width'], $dstSize['height']);
+            //imagick扩展安装难度较大，先用gd库的方案替代，后期再进行优化
+            /*
+            //有则用imagick压缩,没有则用gd压缩
+            if (class_exists('imagick')) {
+                return $this->imagickResize($source, $thumbnail_full, $dstSize['width'], $dstSize['height']);
+            } else {
+              return $this->gdResize($source, $thumbnail_full, $dstSize['width'], $dstSize['height']);
+            }*/
+
+        }
+
+        public function thumbnailPath($file)
+        {
+            $str = explode(".", $file);
+            return $str[0].'_thumb.'.$str[1];
+        }
+        //压缩图片
+        public function compress($source){
+            
+        }
+
+        /**
+         * 使用imagick扩展生成缩略图,图片质量更好更方便
+         * @param $src
+         * @param $dst
+         * @param $width
+         * @param $height
+         */
+        /*
+        public function imagickResize($src, $dst, $width, $height)
+        {
+            $imginfo = getimagesize($src);
+            //图片宽
+            $img_w = $imginfo[0];
+            //图片高
+            $img_h = $imginfo[1];
+            $image = new Imagick($src);
             // 创建缩略图
             //原图宽高大于缩略图
-            if(($img_w > $width) || ($img_h > $height)){
+            if (($img_w > $width) || ($img_h > $height)) {
                 //$image->setImageCompressionQuality(90);
                 $image->cropThumbnailImage( $width, $height );
             }
-            
+
             //将缩略图输出到文件
-            $image->writeImage( $thumbnail_full );
-            
+            $image->writeImage( $dst );
+
             //清理工作
             $image->clear();
         }
-        //压缩图片
-        public function compress($source){
-            
+        */
+
+        /**
+         * 使用gd扩展生成缩略图
+         *
+         * @param $src
+         * @param $dst
+         * @param $width
+         * @param $height
+         *
+         * @return bool
+         */
+        public function gdResize($src, $dst, $width, $height)
+        {
+            $localInfo = getimagesize($src);
+            //创建图像句柄
+            $im = $this->gdCreateImg($src, $localInfo[2]);
+            if (!$im) {
+                return false;
+            }
+            $dstSize = $this->dstSize($localInfo[0], $localInfo[1], $width, $height);
+            $dstImage = @imagecreatetruecolor($dstSize["width"], $dstSize["height"]);
+            $whiteColor = @imagecolorallocatealpha($dstImage, 0, 0, 0, 127);
+            imagefill($dstImage, 0, 0, $whiteColor);
+            $re = @imagecopyresampled($dstImage, $im, 0, 0, 0, 0, $dstSize["width"], $dstSize["height"], $localInfo[0], $localInfo[1]);
+            if (!$re) {
+                return false;
+            }
+            if (!$this->gdCreateImgFile($dstImage, $dst, $localInfo[2])) {
+                return false;
+            }
+            return true;
+        }
+
+        /**
+         * 计算目标文件尺寸
+         *
+         * @param $srcWidth
+         * @param $srcHeight
+         * @param $dstWidth
+         * @param $dstHeight
+         *
+         * @return mixed
+         */
+        public function dstSize($srcWidth, $srcHeight, $dstWidth, $dstHeight)
+        {
+            if (($srcWidth / $srcHeight) < ($dstWidth / $dstHeight)) {
+                $dstWidth = floor($dstHeight * $srcWidth / $srcHeight);
+            } else {
+                $dstHeight = floor($dstWidth * $srcHeight / $srcWidth);
+            }
+            $dstSize["width"] = $dstWidth;
+            $dstSize["height"] = $dstHeight;
+            return $dstSize;
+        }
+
+        /**
+         * 获取图像对象
+         *
+         * @param $src
+         * @param $code
+         *
+         * @return bool|resource
+         */
+        public function gdCreateImg($src, $code)
+        {
+            switch ($code) {
+                case 1:
+                    return imagecreatefromgif($src);
+                case 2:
+                    return imagecreatefromjpeg($src);
+                case 3:
+                    return imagecreatefrompng($src);
+                default :
+                    return false;
+            }
+        }
+
+        /**
+         * 生成缩略图文件
+         * @param $img
+         * @param $path
+         * @param $code
+         * @return bool
+         */
+        public function gdCreateImgFile($img, $path, $code)
+        {
+            switch ($code) {
+                case 1:
+                    return imagegif($img, $path);
+                case 2:
+                    return imagejpeg($img, $path);
+                case 3:
+                    return imagepng($img, $path);
+                default :
+                    return false;
+            }
         }
     }