hb-ot-shaper-khmer-machine.rl

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/*

 * Copyright © 2011,2012  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_OT_SHAPER_KHMER_MACHINE_HH

#define HB_OT_SHAPER_KHMER_MACHINE_HH

#include "hb.hh"

#include "hb-ot-layout.hh"

#include "hb-ot-shaper-indic.hh"

/* buffer var allocations */

#define khmer_category() ot_shaper_var_u8_category() /* khmer_category_t */

using khmer_category_t = unsigned;

#define K_Cat(Cat) khmer_syllable_machine_ex_##Cat

enum khmer_syllable_type_t {

  khmer_consonant_syllable,

  khmer_broken_cluster,

  khmer_non_khmer_cluster,

};

%%{

  machine khmer_syllable_machine;

  alphtype unsigned char;

  write exports;

  write data;

}%%

%%{

# We use category H for spec category Coeng

export C    = 1;

export V    = 2;

export H    = 4;

export ZWNJ = 5;

export ZWJ  = 6;

export PLACEHOLDER = 10;

export DOTTEDCIRCLE = 11;

export Ra   = 15;

export VAbv = 20;

export VBlw = 21;

export VPre = 22;

export VPst = 23;

export Robatic = 25;

export Xgroup  = 26;

export Ygroup  = 27;

c = (C | Ra | V);

cn = c.((ZWJ|ZWNJ)?.Robatic)?;

joiner = (ZWJ | ZWNJ);

xgroup = (joiner*.Xgroup)*;

ygroup = Ygroup*;

# This grammar was experimentally extracted from what Uniscribe allows.

matra_group = VPre? xgroup VBlw? xgroup (joiner?.VAbv)? xgroup VPst?;

syllable_tail = xgroup matra_group xgroup (H.c)? ygroup;

broken_cluster =	Robatic? (H.cn)* (H | syllable_tail);

consonant_syllable =	(cn|PLACEHOLDER|DOTTEDCIRCLE) broken_cluster;

other =			any;

main := |*

	consonant_syllable	=> { found_syllable (khmer_consonant_syllable); };

	broken_cluster		=> { found_syllable (khmer_broken_cluster); buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_BROKEN_SYLLABLE; };

	other			=> { found_syllable (khmer_non_khmer_cluster); };

*|;

}%%

#define found_syllable(syllable_type) \

  HB_STMT_START { \

    if (0) fprintf (stderr, "syllable %u..%u %s\n", ts, te, #syllable_type); \

    for (unsigned int i = ts; i < te; i++) \

      info[i].syllable() = (syllable_serial << 4) | syllable_type; \

    syllable_serial++; \

    if (syllable_serial == 16) syllable_serial = 1; \

  } HB_STMT_END

inline void

find_syllables_khmer (hb_buffer_t *buffer)

  unsigned int p, pe, eof, ts, te, act HB_UNUSED;

  int cs;

  hb_glyph_info_t *info = buffer->info;

%%{

    write init;

    getkey info[p].khmer_category();

}%%

  p = 0;

  pe = eof = buffer->len;

  unsigned int syllable_serial = 1;

%%{

    write exec;

}%%

#undef found_syllable

#endif /* HB_OT_SHAPER_KHMER_MACHINE_HH */