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
1
2
3function set_4pixel($r, $g, $b, $x, $y)
4{
5global $sx, $sy, $pixels;
6
7$ofs = 3 * ($sx * $y + $x);
8$pixels[$ofs] = chr($r);
9$pixels[$ofs + 1] = chr($g);
10$pixels[$ofs + 2] = chr($b);
11$pixels[$ofs + 3] = chr($r);
12$pixels[$ofs + 4] = chr($g);
13$pixels[$ofs + 5] = chr($b);
14$ofs += 3 * $sx;
15$pixels[$ofs] = chr($r);
16$pixels[$ofs + 1] = chr($g);
17$pixels[$ofs + 2] = chr($b);
18$pixels[$ofs + 3] = chr($r);
19$pixels[$ofs + 4] = chr($g);
20$pixels[$ofs + 5] = chr($b);
21}
22//生成数字图象的函数
23function draw2digits($x, $y, $number)
24{
25draw_digit($x, $y, (int) ($number / 10));
26draw_digit($x + 11, $y, $number % 10);
27}
28
29function draw_digit($x, $y, $digit)
30{
31global $sx, $sy, $pixels, $digits, $lines;
32
33$digit = $digits[$digit];
34$m = 8;
35for ($b = 1, $i = 0; $i < 7; $i++, $b *= 2) {
36if (($b & $digit) == $b) {
37$j = $i * 4;
38$x0 = $lines[$j] * $m + $x;
39$y0 = $lines[$j + 1] * $m + $y;
40$x1 = $lines[$j + 2] * $m + $x;
41$y1 = $lines[$j + 3] * $m + $y;
42if ($x0 == $x1) {
43$ofs = 3 * ($sx * $y0 + $x0);
44for ($h = $y0; $h <= $y1; $h++, $ofs += 3 * $sx) {
45$pixels[$ofs] = chr(0);
46$pixels[$ofs + 1] = chr(0);
47$pixels[$ofs + 2] = chr(0);
48}
49} else {
50$ofs = 3 * ($sx * $y0 + $x0);
51for ($w = $x0; $w <= $x1; $w++) {
52$pixels[$ofs++] = chr(0);
53$pixels[$ofs++] = chr(0);
54$pixels[$ofs++] = chr(0);
55}
56}
57}
58}
59}
60
61//将文字加入到图象中
62function add_chunk($type)
63{
64global $result, $data, $chunk, $crc_table;
65
66// chunk :为层
67// length: 4 字节: 用来计算 chunk
68// chunk type: 4 字节
69// chunk data: length bytes
70// CRC: 4 字节: 循环冗余码校验
71
72// copy data and create CRC checksum
73$len = strlen($data);
74$chunk = pack("c*", ($len >> 24) & 255,
75($len >> 16) & 255,
76($len >> 8) & 255,
77$len & 255);
78$chunk .= $type;
79$chunk .= $data;
80
81// calculate a CRC checksum with the bytes chunk[4..len-1]
82$z = 16777215;
83$z |= 255 << 24;
84$c = $z;
85for ($n = 4; $n < strlen($chunk); $n++) {
86$c8 = ($c >> 8) & 0xffffff;
87$c = $crc_table[($c ^ ord($chunk][$n])) & 0xff] ^ $c8;
88}
89$crc = $c ^ $z;
90
91$chunk .= chr(($crc >> 24) & 255);
92$chunk .= chr(($crc >> 16) & 255);
93$chunk .= chr(($crc >> 8) & 255);
94$chunk .= chr($crc & 255);
95
96// 将结果加到$result中
97$result .= $chunk;
98}
99
100
101//主程序
102
103$sx = 80;
104$sy = 21;
105$pixels = "";
106
107// 填充
108for ($h = 0; $h < $sy; $h++) {
109for ($w = 0; $w < $sx; $w++) {
110$r = 100 / $sx * $w + 155;
111$g = 100 / $sy * $h + 155;
112$b = 255 - (100 / ($sx + $sy) * ($w + $h));
113$pixels .= chr($r);
114$pixels .= chr($g);
115$pixels .= chr($b);
116}
117}
118
119$date = getdate();
120$s = $date["seconds"];
121$m = $date["minutes"];
122$h = $date["hours"];
123$digits = array(95, 5, 118, 117, 45, 121, 123, 69, 127, 125);
124$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);
125
126draw2digits(4, 2, $h);
127draw2digits(30, 2, $m);
128draw2digits(56, 2, $s);
129set_4pixel(0, 0, 0, 26, 7);
130set_4pixel(0, 0, 0, 26, 13);
131set_4pixel(0, 0, 0, 52, 7);
132set_4pixel(0, 0, 0, 52, 13);
133
134// 创建循环冗余码校验表
135$z = -306674912; // = 0xedb88320
136for ($n = 0; $n < 256; $n++) {
137$c = $n;
138for ($k = 0; $k < 8; $k++) {
139$c2 = ($c >> 1) & 0x7fffffff;
140if ($c & 1) $c = $z ^ ($c2); else $c = $c2;
141}
142$crc_table[$n] = $c;
143}
144
145// PNG file signature
146$result = pack("c*", 137,80,78,71,13,10,26,10);
147
148// IHDR chunk data:
149// width: 4 bytes
150// height: 4 bytes
151// bit depth: 1 byte (8 bits per RGB value)
152// color type: 1 byte (2 = RGB)
153// compression method: 1 byte (0 = deflate/inflate)
154// filter method: 1 byte (0 = adaptive filtering)
155// interlace method: 1 byte (0 = no interlace)
156$data = pack("c*", ($sx >> 24) & 255,
157($sx >> 16) & 255,
158($sx >> 8) & 255,
159$sx & 255,
160($sy >> 24) & 255,
161($sy >> 16) & 255,
162($sy >> 8) & 255,
163$sy & 255,
1648,
1652,
1660,
1670,
1680);
169add_chunk("IHDR");
170
171// 以下不敢乱翻译，请自行参考
172// scanline:
173// filter byte: 0 = none
174// RGB bytes for the line
175// the scanline is compressed with "zlib", method 8 (RFC-1950):
176// compression method/flags code: 1 byte ($78 = method 8, 32k window)
177// additional flags/check bits: 1 byte ($01: FCHECK = 1, FDICT = 0, FLEVEL = 0)
178// compressed data blocks: n bytes
179// one block (RFC-1951):
180// bit 0: BFINAL: 1 for the last block
181// bit 1 and 2: BTYPE: 0 for no compression
182// next 2 bytes: LEN (LSB first)
183// next 2 bytes: one's complement of LEN
184// LEN bytes uncompressed data
185// check value: 4 bytes (Adler-32 checksum of the uncompressed data)
186//
187$len = ($sx * 3 + 1) * $sy;
188$data = pack("c*", 0x78, 0x01,
1891,
190$len & 255,
191($len >> 8) & 255,
192255 - ($len & 255),
193255 - (($len >> 8) & 255));
194$start = strlen($data);
195$i2 = 0;
196for ($h = 0; $h < $sy; $h++) {
197$data .= chr(0);
198for ($w = 0; $w < $sx * 3; $w++) {
199$data .= $pixels[$i2++];
200}
201}
202
203
204// calculate a Adler32 checksum with the bytes data[start..len-1]
205$s1 = 1;
206$s2 = 0;
207for ($n = $start; $n < strlen($data); $n++) {
208$s1 = ($s1 + ord($data[$n])) % 65521;
209$s2 = ($s2 + $s1) % 65521;
210}
211$adler = ($s2 << 16) | $s1;
212
213$data .= chr(($adler >> 24) & 255);
214$data .= chr(($adler >> 16) & 255);
215$data .= chr(($adler >> 8) & 255);
216$data .= chr($adler & 255);
217add_chunk("IDAT");
218
219// IEND: marks the end of the PNG-file
220$data = "";
221add_chunk("IEND");
222
223// 列印图象
224
225echo($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：
1<html>
2<head>
3<title>test</title>
4<meta content="text/html" http-equiv="Content-Type"/>
5</head>
6<body>
7<img src="Timeimg.php"/> //以图象连接方式调用PHP文件
8</body>
9</html>