Reading Chinese character dot matrix data using PHP programming_PHP tutorial

Background knowledge:

Simplified Chinese national standard font (issued in 1981, Mainland China). There are 7445 characters, including 6773 Chinese characters, including 3755 first-level Chinese characters and 3008 second-level Chinese characters. Using 2-byte (16-bit binary) encoding.

Location code: National standard GB2312 stipulates that all national standard Chinese characters and symbols form a 94×94 matrix. In this square matrix, each row is called a "area" and each column is called a "bit". Therefore, this square matrix actually forms a 94-area area (area numbers are 0 1 to 94 respectively), each There are 94 digits (digit numbers are 01 to 94) of Chinese character sets in the area. The area code and location number of a Chinese character are simply combined to form the "location code" of the Chinese character. In the area code of Chinese characters, the upper two digits are the area code and the lower two digits are the position number. It can be seen that there is a one-to-one correspondence between location codes and Chinese characters or symbols.

Internal code: The internal code of Chinese characters refers to the encoding of Chinese characters in computers. The in-machine code is slightly different from the location code. Why not directly use the area code as the internal code in the computer? This is because the area code and bit code of Chinese characters range from 1 to 94. If the area code is directly used as the internal code, it will conflict with the basic ASCII code. The internal code of Chinese characters is usually related to the computer system used. Currently, for most computer systems in China, the internal code of a Chinese character occupies two bytes, which are called high-order byte and low-order byte respectively, and the relationship between these two bytes and the area code is as follows: Internal code high-order = area Code + A0H (H represents hexadecimal) The low digit of the inner code = bit code + A0H. For example, the area code of the Chinese character "ah" is "1601", and the area code and bit code are expressed in hexadecimal respectively, which is "1001H" , then its internal code is "B0A1H". Among them, B0H is the high-order byte of the internal code, and A1H is the low-order byte of the internal code.

　php(as the current mainstream development language)Code: Returns a string composed of 0 and 1.

＜?php(as the current mainstream development language)
/**
* Read Chinese character dot matrix data
*
* @author legend ＜legendsky@hotmail.com＞
* @link http://www.ugia.cn/?p=82
* @Copyright www.ugia.cn
*/

$str = "People's Republic of China";

$font_file_name = "simsun12.fon" ; // Bitmap font file name
$font_width = 12 ; // Single character width
$font_height = 12 ; // Single character height
$ start_offset = 0 ; // Offset

$fp = fopen ( $font_file_name , "rb" );

$offset_size = $font_width * $font_height / 8 ;
$string_size = $font_width * $font_height ;
$dot_string = "" ;

for ( $i = 0 ; $i ＜ strlen ( $str ); $i ++)
{
if ( ord ( $str { $i }) ＞ 160 )
{
　 // First find the location code, and then calculate its position in the two-dimensional table of location codes, and then get the position of this character in the file Offset
　$offset = (( ord ( $str { $i }) - 0xa1 ) * 94 + ord ( $str { $i + 1 }) - 0xa1 ) * $offset_size ;
　$i ++ ;
　}
else
{
　$offset = ( ord ( $str { $i }) + 156 - 1 ) * $offset_size ;
　}

　// Read its lattice data
　fseek ( $fp , $start_offset + $offset , SEEK_SET );