php画图实例

<?php 
// by morewindows
$imgwidth = 600; 
$imgheight = 400; 
$img = imagecreatetruecolor($imgwidth, $imgheight); 
imagefill($img, 0, 0, imagecolorallocate($img, 240, 240, 240));//设置底色 
$snowflake_size = 30; 
$font_file = "c:\windows\fonts\simhei.ttf";  
//生成大雪花 其实就是调用imagettftext()输出*号 
for ($i=1; $i<=400; $i++)  
{ 
    $font_color = imagecolorallocate($img, mt_rand(100,200), mt_rand(100,200), mt_rand(100,200)); 
    imagettftext($img, $snowflake_size, mt_rand(0, 180), mt_rand(0, $imgwidth),mt_rand(0, $imgheight), $font_color, $font_file, "□");  
} 
//水印文字 
$black_color = imagecolorallocate($img, 0, 0, 0); 
imagettftext($img, 12, 0, $imgwidth - 50 , $imgheight - 20, $black_color, $font_file, "php画图"); 
imagepng($img); 
imagedestroy($img); 
?>