eBookReaderSwitch/mupdf/source/fitz/text.c

331 lines
7.7 KiB
C

#include "mupdf/fitz.h"
#include "fitz-imp.h"
#include <string.h>
/*
Create a new empty fz_text object.
Throws exception on failure to allocate.
*/
fz_text *
fz_new_text(fz_context *ctx)
{
fz_text *text = fz_malloc_struct(ctx, fz_text);
text->refs = 1;
return text;
}
fz_text *
fz_keep_text(fz_context *ctx, const fz_text *textc)
{
fz_text *text = (fz_text *)textc; /* Explicit cast away of const */
return fz_keep_imp(ctx, text, &text->refs);
}
void
fz_drop_text(fz_context *ctx, const fz_text *textc)
{
fz_text *text = (fz_text *)textc; /* Explicit cast away of const */
if (fz_drop_imp(ctx, text, &text->refs))
{
fz_text_span *span = text->head;
while (span)
{
fz_text_span *next = span->next;
fz_drop_font(ctx, span->font);
fz_free(ctx, span->items);
fz_free(ctx, span);
span = next;
}
fz_free(ctx, text);
}
}
static fz_text_span *
fz_new_text_span(fz_context *ctx, fz_font *font, int wmode, int bidi_level, fz_bidi_direction markup_dir, fz_text_language language, fz_matrix trm)
{
fz_text_span *span = fz_malloc_struct(ctx, fz_text_span);
span->font = fz_keep_font(ctx, font);
span->wmode = wmode;
span->bidi_level = bidi_level;
span->markup_dir = markup_dir;
span->language = language;
span->trm = trm;
span->trm.e = 0;
span->trm.f = 0;
return span;
}
static fz_text_span *
fz_add_text_span(fz_context *ctx, fz_text *text, fz_font *font, int wmode, int bidi_level, fz_bidi_direction markup_dir, fz_text_language language, fz_matrix trm)
{
if (!text->tail)
{
text->head = text->tail = fz_new_text_span(ctx, font, wmode, bidi_level, markup_dir, language, trm);
}
else if (text->tail->font != font ||
text->tail->wmode != wmode ||
text->tail->bidi_level != bidi_level ||
text->tail->markup_dir != markup_dir ||
text->tail->language != language ||
text->tail->trm.a != trm.a ||
text->tail->trm.b != trm.b ||
text->tail->trm.c != trm.c ||
text->tail->trm.d != trm.d)
{
text->tail = text->tail->next = fz_new_text_span(ctx, font, wmode, bidi_level, markup_dir, language, trm);
}
return text->tail;
}
static void
fz_grow_text_span(fz_context *ctx, fz_text_span *span, int n)
{
int new_cap = span->cap;
if (span->len + n < new_cap)
return;
while (span->len + n > new_cap)
new_cap = new_cap + 36;
span->items = fz_realloc_array(ctx, span->items, new_cap, fz_text_item);
span->cap = new_cap;
}
/*
Add a glyph/unicode value to a text object.
text: Text object to add to.
font: The font the glyph should be added in.
trm: The transform to use for the glyph.
glyph: The glyph id to add.
unicode: The unicode character for the glyph.
wmode: 1 for vertical mode, 0 for horizontal.
bidi_level: The bidirectional level for this glyph.
markup_dir: The direction of the text as specified in the
markup.
language: The language in use (if known, 0 otherwise)
(e.g. FZ_LANG_zh_Hans).
Throws exception on failure to allocate.
*/
void
fz_show_glyph(fz_context *ctx, fz_text *text, fz_font *font, fz_matrix trm, int gid, int ucs, int wmode, int bidi_level, fz_bidi_direction markup_dir, fz_text_language lang)
{
fz_text_span *span;
if (text->refs != 1)
fz_throw(ctx, FZ_ERROR_GENERIC, "cannot modify shared text objects");
span = fz_add_text_span(ctx, text, font, wmode, bidi_level, markup_dir, lang, trm);
fz_grow_text_span(ctx, span, 1);
span->items[span->len].ucs = ucs;
span->items[span->len].gid = gid;
span->items[span->len].x = trm.e;
span->items[span->len].y = trm.f;
span->len++;
}
/*
Add a UTF8 string to a text object.
text: Text object to add to.
font: The font the string should be added in.
trm: The transform to use.
s: The utf-8 string to add.
wmode: 1 for vertical mode, 0 for horizontal.
bidi_level: The bidirectional level for this glyph.
markup_dir: The direction of the text as specified in the
markup.
language: The language in use (if known, 0 otherwise)
(e.g. FZ_LANG_zh_Hans).
Returns the transform updated with the advance width of the string.
*/
fz_matrix
fz_show_string(fz_context *ctx, fz_text *text, fz_font *user_font, fz_matrix trm, const char *s, int wmode, int bidi_level, fz_bidi_direction markup_dir, fz_text_language language)
{
fz_font *font;
int gid, ucs;
float adv;
while (*s)
{
s += fz_chartorune(&ucs, s);
gid = fz_encode_character_with_fallback(ctx, user_font, ucs, 0, language, &font);
fz_show_glyph(ctx, text, font, trm, gid, ucs, wmode, bidi_level, markup_dir, language);
adv = fz_advance_glyph(ctx, font, gid, wmode);
if (wmode == 0)
trm = fz_pre_translate(trm, adv, 0);
else
trm = fz_pre_translate(trm, 0, -adv);
}
return trm;
}
/*
Find the bounds of a given text object.
text: The text object to find the bounds of.
stroke: Pointer to the stroke attributes (for stroked
text), or NULL (for filled text).
ctm: The matrix in use.
r: pointer to storage for the bounds.
Returns a pointer to r, which is updated to contain the
bounding box for the text object.
*/
fz_rect
fz_bound_text(fz_context *ctx, const fz_text *text, const fz_stroke_state *stroke, fz_matrix ctm)
{
fz_text_span *span;
fz_matrix tm, trm;
fz_rect gbox;
fz_rect bbox;
int i;
bbox = fz_empty_rect;
for (span = text->head; span; span = span->next)
{
if (span->len > 0)
{
tm = span->trm;
for (i = 0; i < span->len; i++)
{
if (span->items[i].gid >= 0)
{
tm.e = span->items[i].x;
tm.f = span->items[i].y;
trm = fz_concat(tm, ctm);
gbox = fz_bound_glyph(ctx, span->font, span->items[i].gid, trm);
bbox = fz_union_rect(bbox, gbox);
}
}
}
}
if (!fz_is_empty_rect(bbox))
{
if (stroke)
bbox = fz_adjust_rect_for_stroke(ctx, bbox, stroke, ctm);
/* Compensate for the glyph cache limited positioning precision */
bbox.x0 -= 1;
bbox.y0 -= 1;
bbox.x1 += 1;
bbox.y1 += 1;
}
return bbox;
}
/*
Convert ISO 639 (639-{1,2,3,5}) language specification
strings losslessly to a 15 bit fz_text_language code.
No validation is carried out. Obviously invalid (out
of spec) codes will be mapped to FZ_LANG_UNSET, but
well-formed (but undefined) codes will be blithely
accepted.
*/
fz_text_language fz_text_language_from_string(const char *str)
{
fz_text_language lang;
if (str == NULL)
return FZ_LANG_UNSET;
if (!strcmp(str, "zh-Hant") ||
!strcmp(str, "zh-HK") ||
!strcmp(str, "zh-MO") ||
!strcmp(str, "zh-SG") ||
!strcmp(str, "zh-TW"))
return FZ_LANG_zh_Hant;
if (!strcmp(str, "zh-Hans") ||
!strcmp(str, "zh-CN"))
return FZ_LANG_zh_Hans;
/* 1st char */
if (str[0] >= 'a' && str[0] <= 'z')
lang = str[0] - 'a' + 1;
else if (str[0] >= 'A' && str[0] <= 'Z')
lang = str[0] - 'A' + 1;
else
return 0;
/* 2nd char */
if (str[1] >= 'a' && str[1] <= 'z')
lang += 27*(str[1] - 'a' + 1);
else if (str[1] >= 'A' && str[1] <= 'Z')
lang += 27*(str[1] - 'A' + 1);
else
return 0; /* There are no valid 1 char language codes */
/* 3nd char */
if (str[2] >= 'a' && str[2] <= 'z')
lang += 27*27*(str[2] - 'a' + 1);
else if (str[2] >= 'A' && str[2] <= 'Z')
lang += 27*27*(str[2] - 'A' + 1);
/* We don't support iso 639-6 4 char codes, cos the standard
* has been withdrawn, and no one uses them. */
return lang;
}
/*
Recover ISO 639 (639-{1,2,3,5}) language specification
strings losslessly from a 15 bit fz_text_language code.
No validation is carried out. See note above.
*/
char *fz_string_from_text_language(char str[8], fz_text_language lang)
{
int c;
/* str is supposed to be at least 8 chars in size */
if (str == NULL)
return NULL;
if (lang == FZ_LANG_zh_Hant)
fz_strlcpy(str, "zh-Hant", 8);
else if (lang == FZ_LANG_zh_Hans)
fz_strlcpy(str, "zh-Hans", 8);
else
{
c = lang % 27;
lang = lang / 27;
str[0] = c == 0 ? 0 : c - 1 + 'a';
c = lang % 27;
lang = lang / 27;
str[1] = c == 0 ? 0 : c - 1 + 'a';
c = lang % 27;
str[2] = c == 0 ? 0 : c - 1 + 'a';
str[3] = 0;
}
return str;
}