PHP native image synthesis and text generation images

There was a post I wrote before that allows you to get pictures from remote addresses and save them locally.
The Moments tag, which was very popular some time ago, can be synthesized using just three custom functions below. The specific parameters have been written by Shitou. If you have any areas that need improvement, please leave a message directly!

/**
* a.合成图片信息 复制一张图片的矩形区域到另外一张图片的矩形区域
* @param  [type] $bg_image  [目标图]
* @param  [type] $sub_image [被添加图]
* @param  [type] $add_x     [目标图x坐标位置]
* @param  [type] $add_y     [目标图y坐标位置]
* @param  [type] $add_w     [目标图宽度区域]
* @param  [type] $add_h     [目标图高度区域]
* @param  [type] $out_image [输出图路径]
* @return [type]            [description]
*/
function image_copy_image($bg_image,$sub_image,$add_x,$add_y,$add_w,$add_h,$out_image){
if($sub_image){
$bg_image_c = imagecreatefromstring(file_get_contents($bg_image));
$sub_image_c = imagecreatefromstring(file_get_contents($sub_image));
imagecopyresampled($bg_image_c, $sub_image_c, $add_x, $add_y, 0, 0, $add_w, $add_h, imagesx($sub_image_c), imagesy($sub_image_c));
//保存到out_image
imagejpeg($bg_image_c, $out_image, 80);
imagedestroy($sub_image_c);
imagedestroy($bg_image_c);
}

}
/**
* b.生成文字图片并插入广告图中
* @param  [type] $filename    [背景路径]
* @param  [type] $text        [文字内容]
* @param  [type] $font        [文字大小]
* @param  [type] $size        [文字画布的宽]
* @param  [type] $width_f     [文字颜色]
* @param  [type] $red         [红]
* @param  [type] $grn	  [绿]
* @param [type] $blu          [蓝]
*/
function create_text($filename,$text,$font,$size,$width_f,$red,$grn,$blu){
$rot  = 0; // 旋转角度
$width = 0; //宽度
$height = 0; //高度
$offset_x = 0; //x偏移
$offset_y = 0; //y偏移
$bounds = array();
$text = autowrap($size, 0, $font, $text,$width_f); // 自动换行处理
/** [字体大小] [角度] [字体名称] [字符串] [预设宽度] */
// 确定边框高度.
$bounds = ImageTTFBBox($size, $rot, $font, "W");
if ($rot < 0) {
$font_height = abs($bounds[7]-$bounds[1]);
} else if ($rot > 0) {
$font_height = abs($bounds[1]-$bounds[7]);
} else {
$font_height = abs($bounds[7]-$bounds[1]);
}
// 确定边框高度.
$bounds = ImageTTFBBox($size, $rot, $font, $text);
if ($rot < 0) {
$width = abs($bounds[4]-$bounds[0]);
$height = abs($bounds[3]-$bounds[7]);
$offset_y = $font_height;
$offset_x = 0;
} else if ($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;
}
$bg = imagecreatetruecolor($width + 20,$height + 20); // 创建画布
$color=imagecolorallocatealpha($bg , 0 , 0 , 0 ,127);//拾取一个完全透明的颜色
imagealphablending($bg ,false);//关闭混合模式，以便透明颜色能覆盖原画布
imagefill($bg , 0 , 0, $color);//填充
imagesavealpha($bg ,true);//设置保存PNG时保留透明通道信息
$textImg = imagecolorallocate($bg, $red, $grn, $blu); // 创建白色
ImageTTFText($bg, $size, 0, 10, $size + 10, $textImg, $font, $text);
imagepng($bg,$filename);
}
/**
* 文字自动换行
* @param  [type] $fontsize    [字体大小]
* @param  [type] $angle       [角度]
* @param  [type] $fontface    [字体名称]
* @param  [type] $string      [字符串]
* @param  [type] $width       [预设宽度]
*/
function autowrap($fontsize, $angle, $fontface, $string, $width) {
$content = "";
// 将字符串拆分成一个个单字 保存到数组 letter 中
preg_match_all("/./u", $string, $arr);
$letter = $arr[0];
foreach ($letter as $l) {
$teststr = $content." ".$l;
$testbox = imagettfbbox($fontsize, $angle, $fontface, $teststr);
// 判断拼接后的字符串是否超过预设的宽度
if (($testbox[2] > $width) && ($content !== "")) {
$content .= PHP_EOL;
}
$content .= $l;
}
return $content;
}