A program that generates PNG format images for the current time without the GD library
Last Update:2017-02-28
Source: Internet
Author: User
Program This program is not the GD library can generate the current time of the PNG format image, to the people's eyes, very valuable reference. Teaman Finishing
<?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 ($b);
}
Functions for generating digital images
function Draw2digits ($x, $y, $number)
{
Draw_digit ($x, $y, (int) ($number/10));
Draw_digit ($x + one, $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;
$x 0 = $lines [$j] * $m + $x;
$y 0 = $lines [$j + 1] * $m + $y;
$x 1 = $lines [$j + 2] * $m + $x;
$y 1 = $lines [$j + 3] * $m + $y;
if ($x 0 = $x 1) {
$ofs = 3 * ($SX * $y 0 + $x 0);
for ($h = $y 0; $h <= $y 1; $h + +, $ofs + + 3 * $sx) {
$pixels [$ofs] = chr (0);
$pixels [$ofs + 1] = chr (0);
$pixels [$ofs + 2] = chr (0);
}
} else {
$ofs = 3 * ($SX * $y 0 + $x 0);
for ($w = $x 0; $w <= $x 1; $w + +) {
$pixels [$ofs + +] = chr (0);
$pixels [$ofs + +] = chr (0);
$pixels [$ofs + +] = chr (0);
}
}
}
}
}
Add text to the image
function Add_chunk ($type)
{
Global $result, $data, $chunk, $CRC _table;
Chunk: For layers
Length:4 bytes: Used to compute chunk
Chunk Type:4 bytes
Chunk Data:length bytes
Crc:4 bytes: Cyclic Redundancy code checksum
Copy data and create CRC checksum
$len = strlen ($data);
$chunk = Pack ("c*", ($len >>) & 255,
($len >>) & 255,
($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 + +) {
$c 8 = ($c >> 8) & 0xFFFFFF;
$c = $CRC _table[($c ^ ord ($chunk [$n])) & 0xFF] ^ $c 8;
}
$CRC = $c ^ $z;
$chunk. = Chr (($CRC >>) & 255);
$chunk. = Chr (($CRC >>) & 255);
$chunk. = Chr (($CRC >> 8) & 255);
$chunk. = Chr ($CRC & 255);
Add the results to the $result
$result. = $chunk;
}
Main program
$SX = 80;
$sy = 21;
$pixels = "";
Fill
for ($h = 0; $h < $sy; $h + +) {
for ($w = 0; $w < $sx; $w + +) {
$r = 100/$SX * $w + 155;
$g = 100/$sy * $h + 155;
$b = 255-($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 (2, $m);
Draw2digits (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);
Create cyclic redundancy Code Check table
$z =-306674912; = 0xedb88320
for ($n = 0; $n < 256; $n + +) {
$c = $n;
for ($k = 0; $k < 8; $k + +) {
$c 2 = ($c >> 1) & 0x7fffffff;
if ($c & 1) $c = $z ^ ($c 2); else $c = $c 2;
}
$CRC _table[$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 >>) & 255,
($sx >>) & 255,
($SX >> 8) & 255,
$SX & 255,
($sy >>) & 255,
($sy >>) & 255,
($sy >> 8) & 255,
$sy & 255,
8,
2,
0,
0,
0);
Add_chunk ("IHDR");
The following do not dare to translate, please own reference
Scanline:
Filter byte:0 = None
RGB bytes for the line
The scanline is compressed with "zlib" and 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 i)
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);
$i 2 = 0;
for ($h = 0; $h < $sy; $h + +) {
$data. = chr (0);
for ($w = 0; $w < $SX * 3; $w + +) {
$data. = $pixels [$i 2++];
}
}
Calculate a Adler32 checksum with the bytes Data[start. LEN-1]
$s 1 = 1;
$s 2 = 0;
for ($n = $start; $n < strlen ($data); $n + +) {
$s 1 = ($s 1 + ord ($data [$n]))% 65521;
$s 2 = ($s 2 + $s 1)% 65521;
}
$adler = ($s 2 << 16) | $s 1;
$data. = Chr (($adler >>) & 255);
$data. = Chr (($adler >>) & 255);
$data. = Chr (($adler >> 8) & 255);
$data. = Chr ($adler & 255);
Add_chunk ("Idat");
Iend:marks the end of the Png-file
$data = "";
Add_chunk ("Iend");
Print image
Echo ($result);
?>
How to call, in fact very simple, save the above as timeimg.php
Then create a new page as follows:
<title>test</title>
<meta http-equiv= "Content-type" content= "text/html" >
<body>
//Call PHP file in image connection mode
</body>