php不用GD库生成当前时间的PNG格式图象的程序

  <?php

  function set_4pixel($r, $g, $b, $x, $y)

  {

  global $sx, $sy, $pixels;

  $ofs = 3 * ($sx * $y + $x);

  $pixels[$ofs] = chr($r);

  $pixels[$ofs + 1] = chr($g);

  $pixels[$ofs + 2] = chr($b);

  $pixels[$ofs + 3] = chr($r);

  $pixels[$ofs + 4] = chr($g);

  $pixels[$ofs + 5] = chr($b);

  $ofs += 3 * $sx;

  $pixels[$ofs] = chr($r);

  $pixels[$ofs + 1] = chr($g);

  $pixels[$ofs + 2] = chr($b);

  $pixels[$ofs + 3] = chr($r);

  $pixels[$ofs + 4] = chr($g);

  $pixels[$ofs + 5] = chr($b);

  }

  //生成数字图象的函数

  function draw2digits($x, $y, $number)

  {

  draw_digit($x, $y, (int) ($number / 10));

  draw_digit($x + 11, $y, $number % 10);

  }

  function draw_digit($x, $y, $digit)

  {

  global $sx, $sy, $pixels, $digits, $lines;

  $digit = $digits[$digit];

  $m = 8;

  for ($b = 1, $i = 0; $i < 7; $i++, $b *= 2) {

  if (($b & $digit) == $b) {

  $j = $i * 4;

  $x0 = $lines[$j] * $m + $x;

  $y0 = $lines[$j + 1] * $m + $y;

  $x1 = $lines[$j + 2] * $m + $x;

  $y1 = $lines[$j + 3] * $m + $y;

  if ($x0 == $x1) {

  $ofs = 3 * ($sx * $y0 + $x0);

  for ($h = $y0; $h <= $y1; $h++, $ofs += 3 * $sx) {

  $pixels[$ofs] = chr(0);

  $pixels[$ofs + 1] = chr(0);

  $pixels[$ofs + 2] = chr(0);

  }

  } else {

  $ofs = 3 * ($sx * $y0 + $x0);

  for ($w = $x0; $w <= $x1; $w++) {

  $pixels[$ofs++] = chr(0);

  $pixels[$ofs++] = chr(0);

  $pixels[$ofs++] = chr(0);

  }

  }

  }

  }

  }

  //将文字加入到图象中

  function add_chunk($type)

  {

  global $result, $data, $chunk, $crc_table;

  // chunk :为层

  // length: 4 字节: 用来计算 chunk

  // chunk type: 4 字节

  // chunk data: length bytes

  // CRC: 4 字节: 循环冗余码校验

  // copy data and create CRC checksum

  $len = strlen($data);

  $chunk = pack("c*", ($len >> 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 << 24;

  $c = $z;

  for ($n = 4; $n < strlen($chunk); $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 < $sy; $h++) {

  for ($w = 0; $w < $sx; $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 < 256; $n++) {

  $c = $n;

  for ($k = 0; $k < 8; $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 < $sy; $h++) {

  $data .= chr(0);

  for ($w = 0; $w < $sx * 3; $w++) {

  $data .= $pixels[$i2++];

  }

  }

  // calculate a Adler32 checksum with the bytes data[start..len-1]

  $s1 = 1;

  $s2 = 0;

  for ($n = $start; $n < strlen($data); $n++) {

  $s1 = ($s1 + ord($data[$n])) % 65521;

  $s2 = ($s2 + $s1) % 65521;

  }

  $adler = ($s2 << 16) | $s1;

  $data .= chr(($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:

  <html>

  <head>

  <title>test</title>

  <meta http-equiv="Content-Type" content="text/html">

  </head>

  <body>

  <img src="Timeimg.php"> //以图象连接方式调用PHP文件

  </body>

  </html>