xemil/src/unicode.c

79 lines
1.9 KiB
C

#include <xemil.h>
#define CAST_I32(x) ((int)(x))
int xl_unicode_count(unsigned char c) {
if(c < 0x80) {
return 1;
}
if(0xc2 <= c && c < 0xe0) {
return 2;
}
if(0xe0 <= c && c < 0xf0) {
return 3;
}
if(0xf0 <= c && c < 0xf8) {
return 4;
}
return 0;
}
static int unicode_later(unsigned char c) {
return 0x80 <= c && c < 0xc0;
}
int xl_unicode_8_to_32(const char* input, int* output) {
const unsigned char* inbuf = (const unsigned char*)input;
int b = xl_unicode_count(inbuf[0]);
if(b == 0) return 0;
if(b == 1) *output = inbuf[0];
if(b == 2) {
if(!unicode_later(inbuf[1])) return 0;
if((inbuf[0] & 0x1e) == 0) return 0;
*output = CAST_I32(inbuf[0] & 0x1f) << 6;
*output |= CAST_I32(inbuf[1] & 0x3f);
}
if(b == 3) {
if(!unicode_later(inbuf[1]) || !unicode_later(inbuf[2])) return 0;
if((inbuf[0] & 0x0f) == 0 && (inbuf[1] & 0x20) == 0) return 0;
*output = CAST_I32(inbuf[0] & 0x0f) << 12;
*output |= CAST_I32(inbuf[1] & 0x3f) << 6;
*output |= CAST_I32(inbuf[2] & 0x3f);
}
if(b == 4) {
if(!unicode_later(inbuf[1]) || !unicode_later(inbuf[2]) || !unicode_later(inbuf[3])) return 0;
if((inbuf[0] & 0x07) == 0 && (inbuf[1] & 0x30) == 0) return 0;
*output = CAST_I32(inbuf[0] & 0x07) << 18;
*output |= CAST_I32(inbuf[1] & 0x3f) << 12;
*output |= CAST_I32(inbuf[2] & 0x3f) << 6;
*output |= CAST_I32(inbuf[3] & 0x3f);
}
return b;
}
int xl_unicode_32_to_8(const int input, char* output) {
if(input < 128) {
output[0] = input;
return 1;
} else if(input < 2048) {
output[0] = 0xc0 | (input >> 6);
output[1] = 0x80 | (input & 0x3f);
return 2;
} else if(input < 65536) {
output[0] = 0xe0 | (input >> 12);
output[1] = 0x80 | ((input >> 6) & 0x3f);
output[2] = 0x80 | (input & 0x3f);
return 3;
} else {
output[0] = 0xf0 | (input >> 18);
output[1] = 0x80 | ((input >> 12) & 0x3f);
output[2] = 0x80 | ((input >> 6) & 0x3f);
output[3] = 0x80 | (input & 0x3f);
return 4;
}
}