PHP对图像函数进行封装,以左下角为坐标原点

绝地灬酷狼 2022-06-08 13:41 126阅读 0赞

目标:

1.调整坐标系,以左下角为坐标原点(0,0)

2.链式操作

3.简化读取图片文件操作

4.简化颜色操作

示例:

$image=new SDraw();
            $dataUrl=$image->create(20,20,'white')
                ->line(0,0,0,19,'black')
                ->line(0,0,19,0)
                ->line(0,0,5,10,'#080')
                ->line(5,10,10,5,'red')
                ->line(10,5,15,19,'green')
                ->line(15,19,19,15,'red')
                ->dataUrl();

类的实现

<?php
    /**
     * 图像绘制类,调整坐标系统,以左下角为原点(0,0) *
     * User: 蓝冰
     * Date: 2017/9/27
     * Time: 9:28
     */
    
    class SDraw
    {
        public function __construct()
        {
        }
    
        //图像宽高,像素
        private $width, $height;
    
        /**
         * @var resource 图像资源句柄
         */
        private $handle;
    
        /**
         * @var string 原始图像文件格式
         */
        private $sourceType;
    
        /**
         * 创建一个新图像
         * @param $width int
         * @param $height int
         * @param $back string 背景颜色
         * @param $trueColor bool 是否是真彩色图像
         * @return $this
         */
        public function create($width, $height, $back = 'white', $trueColor = false)
        {
            $this->width = intval($width);
            $this->height = intval($height);
    
            //是否创建真彩色
            if ($trueColor) {
                $this->handle = imagecreatetruecolor($width, $height);
            } else {
                $this->handle = imagecreate($width, $height);
            }
    
            //如果指定了背景色,则用矩形
            imagerectangle($this->handle, 0, 0, $this->width - 1, $this->height - 1, $this->color($back));
            return $this;
        }
    
        /**
         * 从字符串内容中创建图像(可以是文件内容,也可以是DATAURL)
         * @param $string string
         * @return $this
         */
        public function fromString($string)
        {
            $this->handle = imagecreatefromstring($string);
            $this->sourceType = 'string';
            return $this;
        }
    
        /**
         * 从文件读取一个图像
         * @param $file string 文件名
         * @return $this
         * @throws
         */
        public function fromFile($file)
        {
            //取文件前八个字节
            $header = file_get_contents($file, 0, null, 0, 8);
    
            // GIF 图像
            if (left($header, 3) == 'GIF') {
                $this->handle = imagecreatefromgif($file);
                $this->sourceType = 'gif';
                return $this;
            }
    
            // JPEG 图像
            if (bin2hex(left($header, 2)) == 'ffd8') {
                $this->handle = imagecreatefromjpeg($file);
                $this->sourceType = 'jpeg';
                return $this;
            }
    
            //判断是PNG,  *png
            if (bin2hex($header) == '89504e470d0a1a0a') {
                $this->handle = imagecreatefrompng($file);
                $this->sourceType = 'png';
                return $this;
            }
    
            // WBMP 图像
            if (bin2hex(left($header, 4)) == '00001414') {
                $this->handle = imagecreatefromwbmp($file);
                $this->sourceType = 'wbmp';
                return $this;
            }
    
            // WEBP 图像
            if (left($header, 4) == 'RIFF') {
                $this->handle = imagecreatefromwebp($file);
                $this->sourceType = 'webp';
                return $this;
            }
    
            // GD 图像
            if (bin2hex($header) == 'ffff001400140000') {
                $this->handle = imagecreatefromgd($file);
                $this->sourceType = 'gd';
                return $this;
            }
    
            // GD2 图像
            if (bin2hex(left($header, 3)) == '676432') {
                $this->handle = imagecreatefromgd2($file);
                $this->sourceType = 'gd2';
                return $this;
            }
    
            // XBM 图像
            if ($header == '#define ') {
                $this->handle = imagecreatefromxbm($file);
                $this->sourceType = 'xbm';
                return $this;
            }
    
            //不认识
            throw new Exception('unknown image file:' . $file . ' HEADER:' . bin2hex($header));
        }
    
        /**
         * 创建DataUrl格式
         * @return string
         */
        public function dataUrl()
        {
            //保存原输出缓冲区内容
            $ob = ob_get_clean();
    
            //生成本图像的内容到缓冲区(以PNG格式)
            imagepng($this->handle);
    
            //从缓冲区取回本图像内容
            $image = ob_get_clean();
    
            //恢复缓冲区
            echo $ob;
    
            //创建DataURL
            return 'data:' . image_type_to_mime_type(IMAGETYPE_PNG) . ';base64,' . base64_encode($image);
        }
    
        /**
         * 输出图像内容,以PNG格式
         * @return $this
         */
        public function output()
        {
            header('Content-Type: ' . image_type_to_mime_type(IMAGETYPE_PNG));
            imagepng($this->handle);
            return $this;
        }
    
        /**
         * 析构时释放图像句柄
         */
        public function __destruct()
        {
            //如果已经创建了图像句柄
            if (is_resource($this->handle)) {
                imagedestroy($this->handle);
                $this->handle = null;
            }
        }
    
        //本图像使用到的颜色集
        private $colors = [];
    
        //颜色名称与颜色值对照表
        private $colorNames = [
            'black' => '#000000',
            'navy' => '#000080',
            'darkblue' => '#00008b',
            'mediumblue' => '#0000cd',
            'blue' => '#0000ff',
            'darkgreen' => '#006400',
            'green' => '#008000',
            'teal' => '#008080',
            'darkcyan' => '#008b8b',
            'deepskyblue' => '#00bfff',
            'darkturquoise' => '#00ced1',
            'mediumspringgreen' => '#00fa9a',
            'lime' => '#00ff00',
            'springgreen' => '#00ff7f',
            'aqua' => '#00ffff',
            'cyan' => '#00ffff',
            'midnightblue' => '#191970',
            'dodgerblue' => '#1e90ff',
            'lightseagreen' => '#20b2aa',
            'forestgreen' => '#228b22',
            'seagreen' => '#2e8b57',
            'darkslategray' => '#2f4f4f',
            'limegreen' => '#32cd32',
            'mediumseagreen' => '#3cb371',
            'turquoise' => '#40e0d0',
            'royalblue' => '#4169e1',
            'steelblue' => '#4682b4',
            'darkslateblue' => '#483d8b',
            'mediumturquoise' => '#48d1cc',
            'indigo' => '#4b0082',
            'darkolivegreen' => '#556b2f',
            'cadetblue' => '#5f9ea0',
            'cornflowerblue' => '#6495ed',
            'mediumaquamarine' => '#66cdaa',
            'dimgray' => '#696969',
            'dimgrey' => '#696969',
            'slateblue' => '#6a5acd',
            'olivedrab' => '#6b8e23',
            'slategray' => '#708090',
            'lightslategray' => '#778899',
            'mediumslateblue' => '#7b68ee',
            'lawngreen' => '#7cfc00',
            'chartreuse' => '#7fff00',
            'aquamarine' => '#7fffd4',
            'maroon' => '#800000',
            'purple' => '#800080',
            'olive' => '#808000',
            'gray' => '#808080',
            'skyblue' => '#87ceeb',
            'lightskyblue' => '#87cefa',
            'blueviolet' => '#8a2be2',
            'darkred' => '#8b0000',
            'darkmagenta' => '#8b008b',
            'saddlebrown' => '#8b4513',
            'darkseagreen' => '#8fbc8f',
            'lightgreen' => '#90ee90',
            'mediumpurple' => '#9370db',
            'darkviolet' => '#9400d3',
            'palegreen' => '#98fb98',
            'darkorchid' => '#9932cc',
            'yellowgreen' => '#9acd32',
            'sienna' => '#a0522d',
            'brown' => '#a52a2a',
            'darkgray' => '#a9a9a9',
            'lightblue' => '#add8e6',
            'greenyellow' => '#adff2f',
            'paleturquoise' => '#afeeee',
            'lightsteelblue' => '#b0c4de',
            'powderblue' => '#b0e0e6',
            'firebrick' => '#b22222',
            'darkgoldenrod' => '#b8860b',
            'mediumorchid' => '#ba55d3',
            'rosybrown' => '#bc8f8f',
            'darkkhaki' => '#bdb76b',
            'silver' => '#c0c0c0',
            'mediumvioletred' => '#c71585',
            'indianred' => '#cd5c5c',
            'peru' => '#cd853f',
            'chocolate' => '#d2691e',
            'tan' => '#d2b48c',
            'lightgray' => '#d3d3d3',
            'thistle' => '#d8bfd8',
            'orchid' => '#da70d6',
            'goldenrod' => '#daa520',
            'palevioletred' => '#db7093',
            'crimson' => '#dc143c',
            'gainsboro' => '#dcdcdc',
            'plum' => '#dda0dd',
            'burlywood' => '#deb887',
            'lightcyan' => '#e0ffff',
            'lavender' => '#e6e6fa',
            'darksalmon' => '#e9967a',
            'violet' => '#ee82ee',
            'palegoldenrod' => '#eee8aa',
            'lightcoral' => '#f08080',
            'khaki' => '#f0e68c',
            'aliceblue' => '#f0f8ff',
            'honeydew' => '#f0fff0',
            'azure' => '#f0ffff',
            'sandybrown' => '#f4a460',
            'wheat' => '#f5deb3',
            'beige' => '#f5f5dc',
            'whitesmoke' => '#f5f5f5',
            'mintcream' => '#f5fffa',
            'ghostwhite' => '#f8f8ff',
            'salmon' => '#fa8072',
            'antiquewhite' => '#faebd7',
            'linen' => '#faf0e6',
            'lightgoldenrodyellow' => '#fafad2',
            'oldlace' => '#fdf5e6',
            'red' => '#ff0000',
            'fuchsia' => '#ff00ff',
            'magenta' => '#ff00ff',
            'deeppink' => '#ff1493',
            'orangered' => '#ff4500',
            'tomato' => '#ff6347',
            'hotpink' => '#ff69b4',
            'coral' => '#ff7f50',
            'darkorange' => '#ff8c00',
            'lightsalmon' => '#ffa07a',
            'orange' => '#ffa500',
            'lightpink' => '#ffb6c1',
            'pink' => '#ffc0cb',
            'gold' => '#ffd700',
            'peachpuff' => '#ffdab9',
            'navajowhite' => '#ffdead',
            'moccasin' => '#ffe4b5',
            'bisque' => '#ffe4c4',
            'mistyrose' => '#ffe4e1',
            'blanchedalmond' => '#ffebcd',
            'papayawhip' => '#ffefd5',
            'lavenderblush' => '#fff0f5',
            'seashell' => '#fff5ee',
            'cornsilk' => '#fff8dc',
            'lemonchiffon' => '#fffacd',
            'floralwhite' => '#fffaf0',
            'snow' => '#fffafa',
            'yellow' => '#ffff00',
            'lightyellow' => '#ffffe0',
            'ivory' => '#fffff0',
            'white' => '#ffffff',
        ];
    
        /**
         * 根据给定的颜色: 名称/#rgb/#rrggbb 返回颜色标识符
         * @param $color string 名称/#rgb/#rrggbb
         * @return mixed 颜色标识符
         * @throws Exception 不认识的颜色
         */
        private function color($color)
        {
            //如果不指定颜色,使用最后一次的颜色标识符
            if (!$color) {
                return $this->lastColor;
            }
    
            //全部小写
            $color = strtolower($color);
    
            if (isset($this->colorNames[$color])) {
                //如果给定的是颜色名称
                $rgb = $this->colorNames[$color];
            } else {
                //给定的是颜色值
                //加上左#号
                if (left($color, 1) != '#') {
                    $rgb = '#' . $color;
                } else {
                    $rgb = $color;
                }
    
                //必须以16进制指定颜色值
                if (!preg_match('/^#[a-f0-9]*$/', $rgb)) {
                    throw new Exception('color unknown:' . $color);
                }
    
                //可以是3位 rgb
                if (strlen($rgb) == 4) {
                    $rgb = '#' . $rgb{1} . $rgb{1} . $rgb{2} . $rgb{2} . $rgb{3} . $rgb{3};
                } elseif (strlen($rgb) != 7) {
                    throw new Exception('color error:' . $color);
                }
            }
    
            //如果尚未分配,则分配标识符
            if (!isset($this->colors[$rgb])) {
                $r = hexdec(substr($rgb, 1, 2));
                $g = hexdec(substr($rgb, 3, 2));
                $b = hexdec(substr($rgb, 5, 2));
                $this->colors[$rgb] = imagecolorallocate($this->handle, $r, $g, $b);
            }
    
            //返回标识符
            $this->lastColor = $this->colors[$rgb];
    
            return $this->lastColor;
        }
    
        /**
         * 纵坐标翻转, 以实现 左下角为原点
         * @param $y int 左下角为原点的纵坐标
         * @return int 左上角为原点的纵坐标
         */
        private function y($y)
        {
            $y = intval($y);
            $y = min($y, $this->height - 1);
            return $this->height - 1 - $y;
        }
    
        //最后一次使用的颜色
        private $lastColor = 'black';
    
        /**
         * 画线
         * @param $color string 颜色名称或颜色值
         * @param $x1 int
         * @param $y1 int
         * @param $x2 int
         * @param $y2 int
         * @return $this
         */
        public function line($x1, $y1, $x2, $y2, $color = null)
        {
            imageline($this->handle, $x1, $this->y($y1), $x2, $this->y($y2), $this->color($color));
            return $this;
        }
    
        public function wbmp($file, $foreground = null)
        {
            imagewbmp($this->handle, $file, $foreground);
            return $this;
        }
    
        public function png($file, $quality = null, $filters = null)
        {
            imagepng($this->handle, $file, $quality, $filters);
        }
    }

当前只实现了简单的几个方法,其他方法,用到的时候再补充