summaryrefslogtreecommitdiff
path: root/Build/source/libs/graphite2/graphite2-1.2.0/src/Silf.cpp
blob: 96d78e7754976be85301d3acafd1b51e15a6c732 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
/*  GRAPHITE2 LICENSING

    Copyright 2010, SIL International
    All rights reserved.

    This library is free software; you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published
    by the Free Software Foundation; either version 2.1 of License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should also have received a copy of the GNU Lesser General Public
    License along with this library in the file named "LICENSE".
    If not, write to the Free Software Foundation, 51 Franklin Street, 
    Suite 500, Boston, MA 02110-1335, USA or visit their web page on the 
    internet at http://www.fsf.org/licenses/lgpl.html.

Alternatively, the contents of this file may be used under the terms of the
Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public
License, as published by the Free Software Foundation, either version 2
of the License or (at your option) any later version.
*/
#include <cstdlib>
#include "graphite2/Segment.h"
#include "inc/debug.h"
#include "inc/Endian.h"
#include "inc/Silf.h"
#include "inc/Segment.h"
#include "inc/Rule.h"


using namespace graphite2;

namespace { static const uint32 ERROROFFSET = 0xFFFFFFFF; }

Silf::Silf() throw()
: m_passes(0),
  m_pseudos(0),
  m_classOffsets(0),
  m_classData(0),
  m_justs(0),
  m_numPasses(0),
  m_numJusts(0),
  m_sPass(0),
  m_pPass(0),
  m_jPass(0),
  m_bPass(0),
  m_flags(0),
  m_aPseudo(0),
  m_aBreak(0),
  m_aUser(0),
  m_aBidi(0),
  m_aMirror(0),
  m_iMaxComp(0),
  m_aLig(0),
  m_numPseudo(0),
  m_nClass(0),
  m_nLinear(0),
  m_gEndLine(0)
{
    memset(&m_silfinfo, 0, sizeof m_silfinfo);
}

Silf::~Silf() throw()
{
    releaseBuffers();
}

void Silf::releaseBuffers() throw()
{
    delete [] m_passes;
    delete [] m_pseudos;
    free(m_classOffsets);
    free(m_classData);
    free(m_justs);
    m_passes= 0;
    m_pseudos = 0;
    m_classOffsets = 0;
    m_classData = 0;
    m_justs = 0;
}


bool Silf::readGraphite(const byte * const silf_start, size_t lSilf, const Face& face, uint32 version)
{
    const byte * p = silf_start,
    		   * const silf_end = p + lSilf;

    if (version >= 0x00030000)
    {
        if (lSilf < 28)		{ releaseBuffers(); return false; }
        be::skip<int32>(p);	   // ruleVersion
        be::skip<uint16>(p,2); // passOffset & pseudosOffset
    }
    else if (lSilf < 20) 	{ releaseBuffers(); return false; }
    const uint16 maxGlyph = be::read<uint16>(p);
    m_silfinfo.extra_ascent = be::read<uint16>(p);
    m_silfinfo.extra_descent = be::read<uint16>(p);
    m_numPasses = be::read<uint8>(p);
    m_sPass     = be::read<uint8>(p);
    m_pPass     = be::read<uint8>(p);
    m_jPass     = be::read<uint8>(p);
    m_bPass     = be::read<uint8>(p);
    m_flags     = be::read<uint8>(p);
    be::skip<uint8>(p,2); //  max{Pre,Post}Context.
    m_aPseudo   = be::read<uint8>(p);
    m_aBreak    = be::read<uint8>(p);
    m_aBidi     = be::read<uint8>(p);
    m_aMirror   = be::read<uint8>(p);
    be::skip<byte>(p);     // skip reserved stuff

    // Read Justification levels.
    m_numJusts  = be::read<uint8>(p);
    if (maxGlyph >= face.glyphs().numGlyphs()
        || p + m_numJusts * 8 >= silf_end)  { releaseBuffers(); return false; }
    m_justs = gralloc<Justinfo>(m_numJusts);
    for (uint8 i = 0; i < m_numJusts; i++)
    {
        ::new(m_justs + i) Justinfo(p[0], p[1], p[2], p[3]);
        be::skip<byte>(p,8);
    }

    if (p + sizeof(uint16) + sizeof(uint8)*8 >= silf_end) { releaseBuffers(); return false; }
    m_aLig      = be::read<uint16>(p);
    m_aUser     = be::read<uint8>(p);
    m_iMaxComp  = be::read<uint8>(p);
    be::skip<byte>(p,5); 						// direction and 4 reserved bytes
    be::skip<uint16>(p, be::read<uint8>(p)); 	// don't need critical features yet
    be::skip<byte>(p);							// reserved
    if (p >= silf_end)   { releaseBuffers(); return false; }
    be::skip<uint32>(p, be::read<uint8>(p));	// don't use scriptTag array.
    m_gEndLine  = be::read<uint16>(p);          // lbGID
    if (p >= silf_end)   { releaseBuffers(); return false; }
    const byte * o_passes = p,
               * const passes_start = silf_start + be::read<uint32>(p);

    const size_t num_attrs = face.glyphs().numAttrs();
    if (m_aPseudo   >= num_attrs
        || m_aBreak >= num_attrs
        || m_aBidi  >= num_attrs
        || m_aMirror>= num_attrs
        || m_numPasses > 128 || passes_start >= silf_end
    	|| m_pPass < m_sPass || m_pPass > m_numPasses || m_sPass > m_numPasses
    	|| m_jPass < m_pPass || m_jPass > m_numPasses
    	|| (m_bPass != 0xFF && (m_bPass < m_jPass || m_bPass > m_numPasses))
    	|| m_aLig > 127) { releaseBuffers(); return false; }
    be::skip<uint32>(p, m_numPasses);
    if (p + sizeof(uint16) >= passes_start)  { releaseBuffers(); return false; }
    m_numPseudo = be::read<uint16>(p);
    be::skip<uint16>(p, 3);	// searchPseudo, pseudoSelector, pseudoShift
    if (p + m_numPseudo*(sizeof(uint32) + sizeof(uint16)) >= passes_start) {
        releaseBuffers(); return false;
    }
    m_pseudos = new Pseudo[m_numPseudo];
    for (int i = 0; i < m_numPseudo; i++)
    {
        m_pseudos[i].uid = be::read<uint32>(p);
        m_pseudos[i].gid = be::read<uint16>(p);
    }

    const size_t clen = readClassMap(p, passes_start - p, version);
    if (clen == ERROROFFSET || p + clen > passes_start)  { releaseBuffers(); return false; }

    m_passes = new Pass[m_numPasses];
    for (size_t i = 0; i < m_numPasses; ++i)
    {
        const byte * const pass_start = silf_start + be::read<uint32>(o_passes),
        		   * const pass_end = silf_start + be::peek<uint32>(o_passes);
        if (pass_start > pass_end || pass_end > silf_end) {
        	releaseBuffers(); return false;
        }

        m_passes[i].init(this);
        if (!m_passes[i].readPass(pass_start, pass_end - pass_start, pass_start - silf_start, face))
        {
        	releaseBuffers();
        	return false;
        }
    }

    // fill in gr_faceinfo
    m_silfinfo.upem = face.glyphs().unitsPerEm();
    m_silfinfo.has_bidi_pass = (m_bPass != 0xFF);
    m_silfinfo.justifies = (m_numJusts != 0) || (m_jPass < m_pPass);
    m_silfinfo.line_ends = (m_flags & 1);
    m_silfinfo.space_contextuals = gr_faceinfo::gr_space_contextuals((m_flags >> 2) & 0x7);
    return true;
}

template<typename T> inline uint32 Silf::readClassOffsets(const byte *&p, size_t data_len)
{
	const T cls_off = 2*sizeof(uint16) + sizeof(T)*(m_nClass+1);
	const size_t max_off = (be::peek<T>(p + sizeof(T)*m_nClass) - cls_off)/sizeof(uint16);
	// Check that the last+1 offset is less than or equal to the class map length.
	if (be::peek<T>(p) != cls_off || max_off > (data_len - cls_off)/sizeof(uint16))
		return ERROROFFSET;

	// Read in all the offsets.
	m_classOffsets = gralloc<uint32>(m_nClass+1);
	for (uint32 * o = m_classOffsets, * const o_end = o + m_nClass + 1; o != o_end; ++o)
	{
		*o = (be::read<T>(p) - cls_off)/sizeof(uint16);
		if (*o > max_off)
			return ERROROFFSET;
	}
    return max_off;
}

size_t Silf::readClassMap(const byte *p, size_t data_len, uint32 version)
{
	if (data_len < sizeof(uint16)*2)	return ERROROFFSET;

	m_nClass  = be::read<uint16>(p);
	m_nLinear = be::read<uint16>(p);

	// Check that numLinear < numClass,
	// that there is at least enough data for numClasses offsets.
	if (m_nLinear > m_nClass
	 || (m_nClass + 1) * (version >= 0x00040000 ? sizeof(uint32) : sizeof(uint16))> (data_len - 4))
		return ERROROFFSET;

    
    uint32 max_off;
    if (version >= 0x00040000)
        max_off = readClassOffsets<uint32>(p, data_len);
    else
        max_off = readClassOffsets<uint16>(p, data_len);

    if (max_off == ERROROFFSET) return ERROROFFSET;

	// Check the linear offsets are sane, these must be monotonically increasing.
	for (const uint32 *o = m_classOffsets, * const o_end = o + m_nLinear; o != o_end; ++o)
		if (o[0] > o[1])
			return ERROROFFSET;

	// Fortunately the class data is all uint16s so we can decode these now
    m_classData = gralloc<uint16>(max_off);
    for (uint16 *d = m_classData, * const d_end = d + max_off; d != d_end; ++d)
        *d = be::read<uint16>(p);

	// Check the lookup class invariants for each non-linear class
	for (const uint32 *o = m_classOffsets + m_nLinear, * const o_end = m_classOffsets + m_nClass; o != o_end; ++o)
	{
		const uint16 * lookup = m_classData + *o;
		if (*o > max_off - 4                        // LookupClass doesn't stretch over max_off
         || lookup[0] == 0							// A LookupClass with no looks is a suspicious thing ...
		 || lookup[0] > (max_off - *o - 4)/2  	    // numIDs lookup pairs fits within (start of LookupClass' lookups array, max_off]
		 || lookup[3] != lookup[0] - lookup[1])		// rangeShift:	 numIDs  - searchRange
			return ERROROFFSET;
	}

	return max_off;
}

uint16 Silf::findPseudo(uint32 uid) const
{
    for (int i = 0; i < m_numPseudo; i++)
        if (m_pseudos[i].uid == uid) return m_pseudos[i].gid;
    return 0;
}

uint16 Silf::findClassIndex(uint16 cid, uint16 gid) const
{
    if (cid > m_nClass) return -1;

    const uint16 * cls = m_classData + m_classOffsets[cid];
    if (cid < m_nLinear)        // output class being used for input, shouldn't happen
    {
        for (unsigned int i = 0, n = m_classOffsets[cid + 1]; i < n; ++i, ++cls)
            if (*cls == gid) return i;
        return -1;
    }
    else
    {
    	const uint16 *	min = cls + 4,		// lookups array
    				 * 	max = min + cls[0]*2; // lookups aray is numIDs (cls[0]) uint16 pairs long
    	do
        {
        	const uint16 * p = min + (-2 & ((max-min)/2));
        	if 	(p[0] > gid)	max = p;
        	else 				min = p;
        }
        while (max - min > 2);
        return min[0] == gid ? min[1] : -1;
    }
}

uint16 Silf::getClassGlyph(uint16 cid, unsigned int index) const
{
    if (cid > m_nClass) return 0;

    uint32 loc = m_classOffsets[cid];
    if (cid < m_nLinear)
    {
        if (index < m_classOffsets[cid + 1] - loc)
            return m_classData[index + loc];
    }
    else        // input class being used for output. Shouldn't happen
    {
        for (unsigned int i = loc + 4; i < m_classOffsets[cid + 1]; i += 2)
            if (m_classData[i + 1] == index) return m_classData[i];
    }
    return 0;
}


bool Silf::runGraphite(Segment *seg, uint8 firstPass, uint8 lastPass) const
{
    assert(seg != 0);
    SlotMap            map(*seg);
    FiniteStateMachine fsm(map, seg->getFace()->logger());
    vm::Machine        m(map);
    unsigned int       initSize = seg->slotCount();
#if !defined GRAPHITE2_NTRACING
    json * const dbgout = seg->getFace()->logger();
#endif

    if (lastPass == 0)
    {
        if (firstPass == lastPass)
            return true;
        lastPass = m_numPasses;
    }

    for (size_t i = firstPass; i < lastPass; ++i)
    {
    	// bidi and mirroring
        if (i == m_bPass)
        {
#if !defined GRAPHITE2_NTRACING
        	if (dbgout)
        	{
        		*dbgout << json::item << json::object
        					<< "id"		<< -1
        					<< "slots"	<< json::array;
        		seg->positionSlots(0);
        		for(Slot * s = seg->first(); s; s = s->next())
        			*dbgout		<< dslot(seg, s);
        		*dbgout			<< json::close
        					<< "rules"	<< json::array << json::close
        					<< json::close;
        	}
#endif

        	if (!(seg->dir() & 2))
            	seg->bidiPass(m_aBidi, seg->dir() & 1, m_aMirror);
        	else if (m_aMirror)
            {
                Slot * s;
                for (s = seg->first(); s; s = s->next())
                {
                    unsigned short g = seg->glyphAttr(s->gid(), m_aMirror);
                    if (g && (!(seg->dir() & 4) || !seg->glyphAttr(s->gid(), m_aMirror + 1)))
                        s->setGlyph(seg, g);
                }
            }
        }

#if !defined GRAPHITE2_NTRACING
    	if (dbgout)
    	{
    		*dbgout << json::item << json::object
    					<< "id"		<< i+1
    					<< "slots"	<< json::array;
    		seg->positionSlots(0);
    		for(Slot * s = seg->first(); s; s = s->next())
    			*dbgout		<< dslot(seg, s);
    		*dbgout			<< json::close;
    	}
#endif

        // test whether to reorder, prepare for positioning
        m_passes[i].runGraphite(m, fsm);
        // only subsitution passes can change segment length, cached subsegments are short for their text
        if (m.status() != vm::Machine::finished
        	|| (i < m_pPass && (seg->slotCount() > initSize * MAX_SEG_GROWTH_FACTOR
            || (seg->slotCount() && seg->slotCount() * MAX_SEG_GROWTH_FACTOR < initSize))))
            return false;
    }
    return true;
}