不用GD库生成当前时间的PNG格式图象的程序

5年以前 | 阅读数：947 次 | 编程语言：PHP

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：

test