harfbuzz/src/hb-buffer-deserialize-text.rl

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Ragel

/*
* Copyright © 2013 Google, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_BUFFER_DESERIALIZE_TEXT_HH
#define HB_BUFFER_DESERIALIZE_TEXT_HH
#include "hb.hh"
%%{
machine deserialize_text;
alphtype unsigned char;
write data;
action clear_item {
hb_memset (&info, 0, sizeof (info));
hb_memset (&pos , 0, sizeof (pos ));
}
action add_item {
buffer->add_info (info);
if (unlikely (!buffer->successful))
return false;
buffer->pos[buffer->len - 1] = pos;
*end_ptr = p;
}
action tok {
tok = p;
}
action ensure_glyphs { if (unlikely (!buffer->ensure_glyphs ())) return false; }
action ensure_unicode { if (unlikely (!buffer->ensure_unicode ())) return false; }
action parse_glyph {
/* TODO Unescape delimiters. */
if (!hb_font_glyph_from_string (font,
tok, p - tok,
&info.codepoint))
return false;
}
action parse_hexdigits {if (!parse_hex (tok, p, &info.codepoint )) return false; }
action parse_cluster { if (!parse_uint (tok, p, &info.cluster )) return false; }
action parse_x_offset { if (!parse_int (tok, p, &pos.x_offset )) return false; }
action parse_y_offset { if (!parse_int (tok, p, &pos.y_offset )) return false; }
action parse_x_advance { if (!parse_int (tok, p, &pos.x_advance)) return false; }
action parse_y_advance { if (!parse_int (tok, p, &pos.y_advance)) return false; }
action parse_glyph_flags{ if (!parse_uint (tok, p, &info.mask )) return false; }
unum = '0' | [1-9] digit*;
num = '-'? unum;
glyph_id = unum;
glyph_name = ([^\\\]=@+,#|] | '\\' [\\\]=@+,|]) *;
glyph = (glyph_id | glyph_name) >tok %parse_glyph;
cluster = '=' (unum >tok %parse_cluster);
offsets = '@' (num >tok %parse_x_offset) ',' (num >tok %parse_y_offset );
advances= '+' (num >tok %parse_x_advance) (',' (num >tok %parse_y_advance))?;
glyphflags= '#' (unum >tok %parse_glyph_flags);
glyph_item =
(
glyph
cluster?
offsets?
advances?
glyphflags?
)
>clear_item
@ensure_glyphs
%add_item
;
unicode = 'U' '+' xdigit+ >tok %parse_hexdigits;
unicode_item =
(
unicode
cluster?
)
>clear_item
@ensure_unicode
%add_item
;
glyphs = glyph_item (space* '|' space* glyph_item)* space* ('|'|']')?;
unicodes = unicode_item (space* '|' space* unicode_item)* space* ('|'|'>')?;
main := space* ( ('[' glyphs) | ('<' unicodes) );
}%%
static hb_bool_t
_hb_buffer_deserialize_text (hb_buffer_t *buffer,
const char *buf,
unsigned int buf_len,
const char **end_ptr,
hb_font_t *font)
{
const char *p = buf, *pe = buf + buf_len;
/* Ensure we have positions. */
(void) hb_buffer_get_glyph_positions (buffer, nullptr);
while (p < pe && ISSPACE (*p))
p++;
const char *eof = pe, *tok = nullptr;
int cs;
hb_glyph_info_t info = {0};
hb_glyph_position_t pos = {0};
%%{
write init;
write exec;
}%%
*end_ptr = p;
return p == pe && *(p-1) != ']';
}
#endif /* HB_BUFFER_DESERIALIZE_TEXT_HH */