php 生成文字图片

<?php
class textPNG {
	private $font = './MSYH.TTF'; // 默认字体. 相对于脚本存放目录的相对路径.
	private $msg = "undefined"; // 默认文字.
	private $width = ""; // 默认宽度.
	private $size = 18;
	private $rot = 0; // 旋转角度.
	private $pad = 4.5; // 填充.
	private $transparent = 1; // 文字透明度.
	private $red = 0; // 在黑色背景中...
	private $grn = 0;
	private $blu = 0;
	private $bg_red = 255; // 将文字设置为白色.
	private $bg_grn = 255;
	private $bg_blu = 255;
	public function __construct($paras = array()) {
		empty($paras) && $paras = $_GET;
		isset($paras['text']) && $this->msg = $paras['text'];
		isset($paras['font']) && $this->font = $paras['font'];
		isset($paras['size']) && $this->size = $paras['size'];
		isset($paras['rot']) && $this->rot = $paras['rot'];
		isset($paras['pad']) && $this->pad = $paras['pad'];
		isset($paras['tr']) && $this->transparent = $paras['tr'];
		if (isset($paras['color']) && !empty($paras['color'])) {
			$this_color_hex = HexToRGB($paras['color']);
			$this->red = $this_color_hex['red']; // 文字颜色
			$this->grn = $this_color_hex['green'];
			$this->blu = $this_color_hex['blue'];
		} else {
			isset($paras['red']) && $this->red = $paras['red'];
			isset($paras['grn']) && $this->grn = $paras['grn'];
			isset($paras['blu']) && $this->blu = $paras['blu'];
		}
		if (isset($paras['bg_color']) && !empty($paras['bg_color'])) {
			$bg_color_hex = HexToRGB($paras['bg_color']);
			$this->bg_red = $bg_color_hex['red']; // 背景颜色.
			$this->bg_grn = $bg_color_hex['green'];
			$this->bg_blu = $bg_color_hex['blue'];
		} else {
			isset($paras['bg_red']) && $this->bg_red = $paras['bg_red'];
			isset($paras['bg_grn']) && $this->bg_grn = $paras['bg_grn'];
			isset($paras['bg_blu']) && $this->bg_blu = $paras['bg_blu'];
		}
		if (isset($paras['width']) && !empty($paras['width'])) {
			$this->width = $paras['width'];
			$this->msg = $this->autowrap($this->size, $this->font, $this->msg, $paras['width']);
		} else {
			$this->msg = $this->autowrap($this->size, $this->font, $this->msg);
		}
	}
	public function draw() {
		$width = 0;
		$height = 0;
		$offset_x = 0;
		$offset_y = 0;
		$bounds = array();
		$image = "";
		// 确定文字高度.
		$bounds = ImageTTFBBox($this->size, $this->rot, $this->font, "W");
		if ($this->rot < 0) {
			$font_height = abs($bounds[7] - $bounds[1]);
		} else if ($this->rot > 0) {
			$font_height = abs($bounds[1] - $bounds[7]);
		} else {
			$font_height = abs($bounds[7] - $bounds[1]);
		}
		// 确定边框高度.
		$bounds = ImageTTFBBox($this->size, $this->rot, $this->font, $this->msg);
		if ($this->rot < 0) {
			$width = abs($bounds[4] - $bounds[0]);
			$height = abs($bounds[3] - $bounds[7]);
			$offset_y = $font_height;
			$offset_x = 0;
		} else if ($this->rot > 0) {
			$width = abs($bounds[2] - $bounds[6]);
			$height = abs($bounds[1] - $bounds[5]);
			$offset_y = abs($bounds[7] - $bounds[5]) + $font_height;
			$offset_x = abs($bounds[0] - $bounds[6]);
		} else {
			$width = abs($bounds[4] - $bounds[6]);
			$height = abs($bounds[7] - $bounds[1]);
			$offset_y = $font_height;

			$offset_x = 0;
		}
		if ($this->width) {
			$image = imagecreate($this->width, $height + ($this->pad * 2) + 1);
		} else {
			$image = imagecreate($width + ($this->pad * 2) + 1, $height + ($this->pad * 2) + 1);
		}

		$background = ImageColorAllocate($image, $this->bg_red, $this->bg_grn, $this->bg_blu);
		$foreground = ImageColorAllocate($image, $this->red, $this->grn, $this->blu);
		if ($this->transparent) {
			ImageColorTransparent($image, $background);
		}

		ImageInterlace($image, false);
		// 画图.
		ImageTTFText($image, $this->size, $this->rot, $offset_x + $this->pad, $offset_y + $this->pad, $foreground, $this->font, $this->msg);
		// 输出为png格式.
		Header("Content-type: image/png");
		imagePNG($image);
	}
	// 自动调整宽度（字体大小, 字体名称, 字符串, 预设宽度, 角度）
	public function autowrap($fontsize, $fontface, $string, $width = "", $angle = 0) {
		// 将字符串拆分成一个个单字 保存到数组 letter 中
		for ($i = 0; $i < mb_strlen($string); $i++) {
			$letter[] = mb_substr($string, $i, 1, 'utf-8');
		}
		$letter = array_filter($letter);
		$content = "";
		for ($i = 0; $i < count($letter); $i++) {
			// 换行处理
			if ($letter[$i] == "/" && $letter[$i + 1] == "n") {
				$content .= "\n";
				unset($letter[$i]);
				unset($letter[$i + 1]);
				continue;
			}
			if ($width) {
				$teststr = $content . " " . $letter[$i];
				$testbox = imagettfbbox($fontsize, $angle, $fontface, $teststr);
				if (($testbox[2] > $width) && ($content !== "")) {
					$content .= "\n";
				}
			}
			$content .= $letter[$i];
		}
		return $content;
	}
// Hex颜色转RGB颜色
	public function HexToRGB($colour) {
		if ($colour[0] == '#') {
			$colour = substr($colour, 1);
		}
		if (strlen($colour) == 6) {
			list($r, $g, $b) = array(
				$colour[0] . $colour[1],
				$colour[2] . $colour[3],
				$colour[4] . $colour[5],
			);
		} elseif (strlen($colour) == 3) {
			list($r, $g, $b) = array(
				$colour[0] . $colour[0],
				$colour[1] . $colour[1],
				$colour[2] . $colour[2],
			);
		} else {
			return false;
		}
		$r = hexdec($r);
		$g = hexdec($g);
		$b = hexdec($b);
		return array(
			'red' => $r,
			'green' => $g,
			'blue' => $b,
		);
	}
}
$png = new textPNG();
$png->draw();
?>