> 24) & 255,
($len >> 16) & 255,
($len >> 8) & 255,
$len & 255);
$chunk .= $type;
$chunk .= $data;
// calculate a crc checksum with the bytes chunk[4..len-1]
$z = 16777215;
$z |= 255 $c = $z;
for ($n = 4; $n $c8 = ($c >> 8) & 0xffffff;
$c = $crc_table[($c ^ ord($chunk][$n])) & 0xff] ^ $c8;
}
$crc = $c ^ $z;
$chunk .= chr(($crc >> 24) & 255);
$chunk .= chr(($crc >> 16) & 255);
$chunk .= chr(($crc >> 8) & 255);
$chunk .= chr($crc & 255);
// 将结果加到$result中
$result .= $chunk;
}
//主程序
$sx = 80;
$sy = 21;
$pixels = ;
// 填充
for ($h = 0; $h for ($w = 0; $w $r = 100 / $sx * $w + 155;
$g = 100 / $sy * $h + 155;
$b = 255 - (100 / ($sx + $sy) * ($w + $h));
$pixels .= chr($r);
$pixels .= chr($g);
$pixels .= chr($b);
}
}
$date = getdate();
$s = $date[seconds];
$m = $date[minutes];
$h = $date[hours];
$digits = array(95, 5, 118, 117, 45, 121, 123, 69, 127, 125);
$lines = array(1, 1, 1, 2, 0, 1, 0, 2, 1, 0, 1, 1, 0, 0, 0, 1, 0, 2, 1, 2, 0, 1, 1, 1, 0, 0, 1, 0);
draw2digits(4, 2, $h);
draw2digits(30, 2, $m);
draw2digits(56, 2, $s);
set_4pixel(0, 0, 0, 26, 7);
set_4pixel(0, 0, 0, 26, 13);
set_4pixel(0, 0, 0, 52, 7);
set_4pixel(0, 0, 0, 52, 13);
// 创建循环冗余码校验表
$z = -306674912; // = 0xedb88320
for ($n = 0; $n $c = $n;
for ($k = 0; $k $c2 = ($c >> 1) & 0x7fffffff;
if ($c & 1) $c = $z ^ ($c2); else $c = $c2;
}
$crc_table[$n] = $c;
}
// png file signature
$result = pack(c*, 137,80,78,71,13,10,26,10);
// ihdr chunk data:
// width: 4 bytes
// height: 4 bytes
// bit depth: 1 byte (8 bits per rgb value)
// color type: 1 byte (2 = rgb)
// compression method: 1 byte (0 = deflate/inflate)
// filter method: 1 byte (0 = adaptive filtering)
// interlace method: 1 byte (0 = no interlace)
$data = pack(c*, ($sx >> 24) & 255,
($sx >> 16) & 255,
($sx >> 8) & 255,
$sx & 255,
($sy >> 24) & 255,
($sy >> 16) & 255,
($sy >> 8) & 255,
$sy & 255,
8,
2,
0,
0,
0);
add_chunk(ihdr);
// 以下不敢乱翻译，请自行参考
// scanline:
// filter byte: 0 = none
// rgb bytes for the line
// the scanline is compressed with zlib, method 8 (rfc-1950):
// compression method/flags code: 1 byte ($78 = method 8, 32k window)
// additional flags/check bits: 1 byte ($01: fcheck = 1, fdict = 0, flevel = 0)
// compressed data blocks: n bytes
// one block (rfc-1951):
// bit 0: bfinal: 1 for the last block
// bit 1 and 2: btype: 0 for no compression
// next 2 bytes: len (lsb first)
// next 2 bytes: one's complement of len
// len bytes uncompressed data
// check value: 4 bytes (adler-32 checksum of the uncompressed data)
//
$len = ($sx * 3 + 1) * $sy;
$data = pack(c*, 0x78, 0x01,
1,
$len & 255,
($len >> 8) & 255,
255 - ($len & 255),
255 - (($len >> 8) & 255));
$start = strlen($data);
$i2 = 0;
for ($h = 0; $h $data .= chr(0);
for ($w = 0; $w $data .= $pixels[$i2++];
}
}
// calculate a adler32 checksum with the bytes data[start..len-1]
$s1 = 1;
$s2 = 0;
for ($n = $start; $n $s1 = ($s1 + ord($data[$n])) % 65521;
$s2 = ($s2 + $s1) % 65521;
}
$adler = ($s2
$data .= chr(($adler >> 24) & 255);
$data .= chr(($adler >> 16) & 255);
$data .= chr(($adler >> 8) & 255);
$data .= chr($adler & 255);
add_chunk(idat);
// iend: marks the end of the png-file
$data = ;
add_chunk(iend);
// 列印图象
echo($result);
?>
//如何调用，其实很简单，将上面存为timeimg.php
//然后新建一个页面如下：
test
//以图象连接方式调用php文件
http://www.bkjia.com/phpjc/314953.htmlwww.bkjia.comtruehttp://www.bkjia.com/phpjc/314953.htmltecharticle该程序是不用gd库可以生成当前时间的png格式图象，给人大开眼界，很有参考价值. teaman整理 ?php function set_4pixel($r, $g, $b, $x, $y) { global $sx,...