Files
crib/src/utils/unicode.cc

141 lines
3.7 KiB
C++

#include "utfcpp/source/utf8.h"
#include "utils/utils.h"
int display_width(const char *str, size_t len) {
if (!str || !*str)
return 0;
if (str[0] == '\t')
return 4;
unicode_width_state_t state;
unicode_width_init(&state);
int width = 0;
for (size_t j = 0; j < len; j++) {
unsigned char c = str[j];
if (c < 128) {
int char_width = unicode_width_process(&state, c);
if (char_width > 0)
width += char_width;
} else {
uint_least32_t cp;
size_t bytes = grapheme_decode_utf8(str + j, strlen(str) - j, &cp);
if (bytes > 1) {
int char_width = unicode_width_process(&state, cp);
if (char_width > 0)
width += char_width;
j += bytes - 1;
}
}
}
return width;
}
uint8_t utf8_codepoint_width(unsigned char c) {
if ((c & 0x80) == 0x00)
return 1;
if ((c & 0xE0) == 0xC0)
return 2;
if ((c & 0xF0) == 0xE0)
return 3;
if ((c & 0xF8) == 0xF0)
return 4;
return 1;
}
uint32_t get_visual_col_from_bytes(const char *line, uint32_t len,
uint32_t byte_limit) {
if (!line)
return 0;
uint32_t visual_col = 0;
uint32_t current_byte = 0;
if (len > 0 && line[len - 1] == '\n')
len--;
while (current_byte < byte_limit && current_byte < len) {
uint32_t inc = grapheme_next_character_break_utf8(line + current_byte,
len - current_byte);
if (current_byte + inc > byte_limit)
break;
int w = display_width(line + current_byte, inc);
if (w < 0)
w = 0;
visual_col += (uint32_t)w;
current_byte += inc;
}
return visual_col;
}
uint32_t get_bytes_from_visual_col(const char *line, uint32_t len,
uint32_t target_visual_col) {
if (!line)
return 0;
uint32_t current_byte = 0;
uint32_t visual_col = 0;
if (len > 0 && line[len - 1] == '\n')
len--;
while (current_byte < len && visual_col < target_visual_col) {
uint32_t inc = grapheme_next_character_break_utf8(line + current_byte,
len - current_byte);
int w = display_width(line + current_byte, inc);
if (w < 0)
w = 0;
if (visual_col + (uint32_t)w > target_visual_col)
return current_byte;
visual_col += (uint32_t)w;
current_byte += inc;
}
return current_byte;
}
uint32_t count_clusters(const char *line, size_t len, size_t from, size_t to) {
uint32_t count = 0;
size_t pos = from;
while (pos < to && pos < len) {
size_t next =
pos + grapheme_next_character_break_utf8(line + pos, len - pos);
if (next > to)
break;
pos = next;
count++;
}
return count;
}
size_t utf8_offset_to_utf16(const char *utf8, size_t utf8_len,
size_t byte_offset) {
if (byte_offset > utf8_len)
return byte_offset;
const char *start = utf8;
const char *mid = utf8 + byte_offset;
if (!utf8::is_valid(start, mid))
assert(0 && "invalid utf8");
size_t utf16_offset = 0;
for (auto it = start; it < mid;) {
uint32_t codepoint = utf8::next(it, mid);
if (codepoint <= 0xFFFF)
utf16_offset += 1;
else
utf16_offset += 2;
}
return utf16_offset;
}
size_t utf16_offset_to_utf8(const char *utf8, size_t utf8_len,
size_t utf16_offset) {
const char *start = utf8;
const char *end = utf8 + utf8_len;
const char *it = start;
size_t utf16_count = 0;
while (it < end) {
if (utf16_count >= utf16_offset)
break;
const char *prev = it;
uint32_t codepoint = utf8::next(it, end);
if (codepoint <= 0xFFFF)
utf16_count += 1;
else
utf16_count += 2;
if (utf16_count > utf16_offset)
return prev - start;
}
return it - start;
}