/*
* utf-8文字列を描画した際の幅を取得する
*/
int get_utf8_width(const char *mbs)
{
uint32_t c;
int mblen, w;
/* 1文字ずつ描画する */
w = 0;
c = 0; /* warning avoidance on gcc 5.3.1 */
while (*mbs != '\0') {
/* 文字を取得する */
mblen = utf8_to_utf32(mbs, &c);
if (mblen == -1)
return -1;
/* 幅を取得する */
w += get_glyph_width(c);
/* 次の文字へ移動する */
mbs += mblen;
}
return w;
}
wraptext_t*
word_wrap_text(const font_t* font, const char* text, int width)
{
char* buffer = NULL;
uint8_t ch_byte;
char* carry;
size_t ch_size;
uint32_t cp;
int glyph_width;
bool is_line_end = false;
int line_idx;
int line_width;
int max_lines = 10;
char* last_break;
char* last_space;
char* last_tab;
char* line_buffer;
size_t line_length;
char* new_buffer;
size_t pitch;
uint32_t utf8state;
wraptext_t* wraptext;
const char *p, *start;
if (!(wraptext = calloc(1, sizeof(wraptext_t)))) goto on_error;
// allocate initial buffer
get_font_metrics(font, &glyph_width, NULL, NULL);
pitch = 4 * (glyph_width > 0 ? width / glyph_width : width) + 3;
if (!(buffer = malloc(max_lines * pitch))) goto on_error;
if (!(carry = malloc(pitch))) goto on_error;
// run through one character at a time, carrying as necessary
line_buffer = buffer; line_buffer[0] = '\0';
line_idx = 0; line_width = 0; line_length = 0;
memset(line_buffer, 0, pitch); // fill line with NULs
p = text;
do {
utf8state = UTF8_ACCEPT; start = p;
while (utf8decode(&utf8state, &cp, ch_byte = *p++) > UTF8_REJECT);
if (utf8state == UTF8_REJECT && ch_byte == '\0')
--p; // don't eat NUL terminator
ch_size = p - start;
cp = cp == 0x20AC ? 128
: cp == 0x201A ? 130
: cp == 0x0192 ? 131
: cp == 0x201E ? 132
: cp == 0x2026 ? 133
: cp == 0x2020 ? 134
: cp == 0x2021 ? 135
: cp == 0x02C6 ? 136
: cp == 0x2030 ? 137
: cp == 0x0160 ? 138
: cp == 0x2039 ? 139
: cp == 0x0152 ? 140
: cp == 0x017D ? 142
: cp == 0x2018 ? 145
: cp == 0x2019 ? 146
: cp == 0x201C ? 147
: cp == 0x201D ? 148
: cp == 0x2022 ? 149
: cp == 0x2013 ? 150
: cp == 0x2014 ? 151
: cp == 0x02DC ? 152
: cp == 0x2122 ? 153
: cp == 0x0161 ? 154
: cp == 0x203A ? 155
: cp == 0x0153 ? 156
: cp == 0x017E ? 158
: cp == 0x0178 ? 159
: cp;
cp = utf8state == UTF8_ACCEPT
? cp < (uint32_t)font->num_glyphs ? cp : 0x1A
: 0x1A;
switch (cp) {
case '\n': case '\r': // explicit newline
if (cp == '\r' && *p == '\n') ++text; // CRLF
is_line_end = true;
break;
case '\t': // tab
line_buffer[line_length++] = cp;
line_width += get_text_width(font, " ");
is_line_end = false;
break;
case '\0': // NUL terminator
is_line_end = line_length > 0; // commit last line on EOT
break;
default: // default case, copy character as-is
memcpy(line_buffer + line_length, start, ch_size);
line_length += ch_size;
line_width += get_glyph_width(font, cp);
is_line_end = false;
}
if (is_line_end) carry[0] = '\0';
if (line_width > width || line_length >= pitch - 1) {
// wrap width exceeded, carry current word to next line
is_line_end = true;
last_space = strrchr(line_buffer, ' ');
last_tab = strrchr(line_buffer, '\t');
last_break = last_space > last_tab ? last_space : last_tab;
if (last_break != NULL) // word break (space or tab) found
strcpy(carry, last_break + 1);
else // no word break, so just carry last character
sprintf(carry, "%c", line_buffer[line_length - 1]);
line_buffer[line_length - strlen(carry)] = '\0';
}
if (is_line_end) {
// do we need to enlarge the buffer?
if (++line_idx >= max_lines) {
max_lines *= 2;
if (!(new_buffer = realloc(buffer, max_lines * pitch)))
goto on_error;
buffer = new_buffer;
line_buffer = buffer + line_idx * pitch;
}
else
line_buffer += pitch;
memset(line_buffer, 0, pitch); // fill line with NULs
// copy carry text into new line
line_width = get_text_width(font, carry);
line_length = strlen(carry);
strcpy(line_buffer, carry);
}
} while (cp != '\0');
free(carry);
wraptext->num_lines = line_idx;
wraptext->buffer = buffer;
wraptext->pitch = pitch;
return wraptext;
on_error:
free(buffer);
free(wraptext);
return NULL;
}
