不用GD库生成当前时间的PNG格式图象的程序

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, $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='https://www.uahao.com/bcjs/Timeimg.php'>//以图象连接方式调用PHP文件 </body> </html>