Program _php for using the GD library to generate PNG format images for the current time

The program is not using the GD library can generate the current time of the PNG format image, to open the eyes of the people, very valuable reference. Teaman Finishing

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 an image
function Add_chunk ($type)
{
Global $result, $data, $chunk, $CRC _table;

Chunk: For layers
Length:4 bytes: Used to calculate chunk
Chunk Type:4 bytes
Chunk Data:length bytes
Crc:4 bytes: Cyclic Redundancy code Check

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 results to $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 + 15 5;
$g = 100/$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 = Arrays (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, N);

//Create cyclic redundancy check table
$z = -306674912;//= 0xedb88320
for ($n = 0; $n <; $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 refer yourself
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);
$i 2 = 0;
for ($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, will be saved as timeimg.php
Then create a new page as follows:

Test



Invoking PHP files with image connection

http://www.bkjia.com/PHPjc/314953.html www.bkjia.com true http://www.bkjia.com/PHPjc/314953.html techarticle The program is not using the GD library can generate the current time of the PNG format image, to open the eyes of the people, very valuable reference. Teaman? PHP function Set_4pixel ($r, $g, $b, $x, $y) {global $SX,...

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