mirror of https://github.com/0intro/conterm
163 lines
2.3 KiB
C
163 lines
2.3 KiB
C
#include <u.h>
|
|
#include <libc.h>
|
|
|
|
enum
|
|
{
|
|
Bit1 = 7,
|
|
Bitx = 6,
|
|
Bit2 = 5,
|
|
Bit3 = 4,
|
|
Bit4 = 3,
|
|
|
|
T1 = ((1<<(Bit1+1))-1) ^ 0xFF, /* 0000 0000 */
|
|
Tx = ((1<<(Bitx+1))-1) ^ 0xFF, /* 1000 0000 */
|
|
T2 = ((1<<(Bit2+1))-1) ^ 0xFF, /* 1100 0000 */
|
|
T3 = ((1<<(Bit3+1))-1) ^ 0xFF, /* 1110 0000 */
|
|
T4 = ((1<<(Bit4+1))-1) ^ 0xFF, /* 1111 0000 */
|
|
|
|
Rune1 = (1<<(Bit1+0*Bitx))-1, /* 0000 0000 0111 1111 */
|
|
Rune2 = (1<<(Bit2+1*Bitx))-1, /* 0000 0111 1111 1111 */
|
|
Rune3 = (1<<(Bit3+2*Bitx))-1, /* 1111 1111 1111 1111 */
|
|
|
|
Maskx = (1<<Bitx)-1, /* 0011 1111 */
|
|
Testx = Maskx ^ 0xFF, /* 1100 0000 */
|
|
|
|
Bad = Runeerror,
|
|
};
|
|
|
|
int
|
|
chartorune(Rune *rune, char *str)
|
|
{
|
|
int c, c1, c2;
|
|
long l;
|
|
|
|
/*
|
|
* one character sequence
|
|
* 00000-0007F => T1
|
|
*/
|
|
c = *(uchar*)str;
|
|
if(c < Tx) {
|
|
*rune = c;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* two character sequence
|
|
* 0080-07FF => T2 Tx
|
|
*/
|
|
c1 = *(uchar*)(str+1) ^ Tx;
|
|
if(c1 & Testx)
|
|
goto bad;
|
|
if(c < T3) {
|
|
if(c < T2)
|
|
goto bad;
|
|
l = ((c << Bitx) | c1) & Rune2;
|
|
if(l <= Rune1)
|
|
goto bad;
|
|
*rune = l;
|
|
return 2;
|
|
}
|
|
|
|
/*
|
|
* three character sequence
|
|
* 0800-FFFF => T3 Tx Tx
|
|
*/
|
|
c2 = *(uchar*)(str+2) ^ Tx;
|
|
if(c2 & Testx)
|
|
goto bad;
|
|
if(c < T4) {
|
|
l = ((((c << Bitx) | c1) << Bitx) | c2) & Rune3;
|
|
if(l <= Rune2)
|
|
goto bad;
|
|
*rune = l;
|
|
return 3;
|
|
}
|
|
|
|
/*
|
|
* bad decoding
|
|
*/
|
|
bad:
|
|
*rune = Bad;
|
|
return 1;
|
|
}
|
|
|
|
int
|
|
runetochar(char *str, Rune *rune)
|
|
{
|
|
long c;
|
|
|
|
/*
|
|
* one character sequence
|
|
* 00000-0007F => 00-7F
|
|
*/
|
|
c = *rune;
|
|
if(c <= Rune1) {
|
|
str[0] = c;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* two character sequence
|
|
* 0080-07FF => T2 Tx
|
|
*/
|
|
if(c <= Rune2) {
|
|
str[0] = T2 | (c >> 1*Bitx);
|
|
str[1] = Tx | (c & Maskx);
|
|
return 2;
|
|
}
|
|
|
|
/*
|
|
* three character sequence
|
|
* 0800-FFFF => T3 Tx Tx
|
|
*/
|
|
str[0] = T3 | (c >> 2*Bitx);
|
|
str[1] = Tx | ((c >> 1*Bitx) & Maskx);
|
|
str[2] = Tx | (c & Maskx);
|
|
return 3;
|
|
}
|
|
|
|
int
|
|
runelen(long c)
|
|
{
|
|
Rune rune;
|
|
char str[10];
|
|
|
|
rune = c;
|
|
return runetochar(str, &rune);
|
|
}
|
|
|
|
int
|
|
runenlen(Rune *r, int nrune)
|
|
{
|
|
int nb, c;
|
|
|
|
nb = 0;
|
|
while(nrune--) {
|
|
c = *r++;
|
|
if(c <= Rune1)
|
|
nb++;
|
|
else
|
|
if(c <= Rune2)
|
|
nb += 2;
|
|
else
|
|
nb += 3;
|
|
}
|
|
return nb;
|
|
}
|
|
|
|
int
|
|
fullrune(char *str, int n)
|
|
{
|
|
int c;
|
|
|
|
if(n > 0) {
|
|
c = *(uchar*)str;
|
|
if(c < Tx)
|
|
return 1;
|
|
if(n > 1)
|
|
if(c < T3 || n > 2)
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|