Php does not use the GD library to generate PNG format images for the current time

This program can generate PNG images of the current time without using the GD Library, which is of great reference value. teaman: This program does not use the GD library to generate PNG images of the current time. it is very helpful for you. teaman sorting

 > 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) & 0 xffffff; $ c = $ crc_table [($ c ^ ord ($ chunk] [$ n]) & 0xff] ^ $ c8 ;}$ crc = $ c ^ $ z; $ chunk. = chr ($ crc> 24) & 255); $ chunk. = chr ($ crc> 1 6) & 255); $ chunk. = chr ($ crc> 8) & 255); $ chunk. = chr ($ crc & 255); // add the result to $ 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-(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, 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, 0, 26, 13); set_4pixel (0, 0, 0, 52, 7); set_4pixel (0, 0, 0, 0, 52, 13); // Create a cyclic verification code table $ z =-306674912; // = 0xedb88320 for ($ n = 0; $ n <256; $ n ++) {$ c = $ n; for ($ k = 0; $ k <8; $ k ++) {$ c2 = ($ c> 1) & 0x7fffff; 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) & amp; 255, ($ sx> 8) & amp; 255, $ sx & amp; 255, ($ sy> & gt; 24) & amp; 255, ($ sy> & gt; 16) & amp; 255, ($ sy> 8) & 255, $ sy & 255, 8, 2, 0, 0, 0); add_chunk ("IHDR"); // do not dare to translate in disorder below, please refer to // 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, 32 k 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 compre Ssion // 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"); // print the image echo ($ result);?> // How to call it is actually very simple. Save the above as Timeimg. php // and then create a new page as follows:  Test 
   // Call the php file through image connection