harfbuzz/src/graphite2/src/Silf.cpp

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/* 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"
#include "inc/Error.h"
#include "inc/ShapingContext.hpp"
using namespace graphite2;
namespace { static const uint32_t 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_dir(0),
m_aPseudo(0),
m_aBreak(0),
m_aUser(0),
m_aBidi(0),
m_aMirror(0),
m_aPassBits(0),
m_iMaxComp(0),
m_aCollision(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, Face& face, uint32_t version)
{
const byte * p = silf_start,
* const silf_end = p + lSilf;
Error e;
if (e.test(version >= 0x00060000, E_BADSILFVERSION))
{
releaseBuffers(); return face.error(e);
}
if (version >= 0x00030000)
{
if (e.test(lSilf < 28, E_BADSIZE)) { releaseBuffers(); return face.error(e); }
be::skip<int32_t>(p); // ruleVersion
be::skip<uint16_t>(p,2); // passOffset & pseudosOffset
}
else if (e.test(lSilf < 20, E_BADSIZE)) { releaseBuffers(); return face.error(e); }
const uint16_t maxGlyph = be::read<uint16_t>(p);
m_silfinfo.extra_ascent = be::read<uint16_t>(p);
m_silfinfo.extra_descent = be::read<uint16_t>(p);
m_numPasses = be::read<uint8_t>(p);
m_sPass = be::read<uint8_t>(p);
m_pPass = be::read<uint8_t>(p);
m_jPass = be::read<uint8_t>(p);
m_bPass = be::read<uint8_t>(p);
m_flags = be::read<uint8_t>(p);
be::skip<uint8_t>(p,2); // max{Pre,Post}Context.
m_aPseudo = be::read<uint8_t>(p);
m_aBreak = be::read<uint8_t>(p);
m_aBidi = be::read<uint8_t>(p);
m_aMirror = be::read<uint8_t>(p);
m_aPassBits = be::read<uint8_t>(p);
// Read Justification levels.
m_numJusts = be::read<uint8_t>(p);
if (e.test(maxGlyph >= face.glyphs().numGlyphs(), E_BADMAXGLYPH)
|| e.test(p + m_numJusts * 8 >= silf_end, E_BADNUMJUSTS))
{
releaseBuffers(); return face.error(e);
}
if (m_numJusts)
{
m_justs = gralloc<Justinfo>(m_numJusts);
if (e.test(!m_justs, E_OUTOFMEM)) return face.error(e);
for (uint8_t 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 (e.test(p + sizeof(uint16_t) + sizeof(uint8_t)*8 >= silf_end, E_BADENDJUSTS)) { releaseBuffers(); return face.error(e); }
m_aLig = be::read<uint16_t>(p);
m_aUser = be::read<uint8_t>(p);
m_iMaxComp = be::read<uint8_t>(p);
m_dir = be::read<uint8_t>(p) - 1;
m_aCollision = be::read<uint8_t>(p);
be::skip<byte>(p,3);
be::skip<uint16_t>(p, be::read<uint8_t>(p)); // don't need critical features yet
be::skip<byte>(p); // reserved
if (e.test(p >= silf_end, E_BADCRITFEATURES)) { releaseBuffers(); return face.error(e); }
be::skip<uint32_t>(p, be::read<uint8_t>(p)); // don't use scriptTag array.
if (e.test(p + sizeof(uint16_t) + sizeof(uint32_t) >= silf_end, E_BADSCRIPTTAGS)) { releaseBuffers(); return face.error(e); }
m_gEndLine = be::read<uint16_t>(p); // lbGID
const byte * o_passes = p;
uint32_t passes_start = be::read<uint32_t>(p);
const size_t num_attrs = face.glyphs().numAttrs();
if (e.test(m_aPseudo >= num_attrs, E_BADAPSEUDO)
|| e.test(m_aBreak >= num_attrs, E_BADABREAK)
|| e.test(m_aBidi >= num_attrs, E_BADABIDI)
|| e.test(m_aMirror>= num_attrs, E_BADAMIRROR)
|| e.test(m_aCollision && m_aCollision >= num_attrs - 5, E_BADACOLLISION)
|| e.test(m_numPasses > 128, E_BADNUMPASSES) || e.test(passes_start >= lSilf, E_BADPASSESSTART)
|| e.test(m_pPass < m_sPass, E_BADPASSBOUND) || e.test(m_pPass > m_numPasses, E_BADPPASS) || e.test(m_sPass > m_numPasses, E_BADSPASS)
|| e.test(m_jPass < m_pPass, E_BADJPASSBOUND) || e.test(m_jPass > m_numPasses, E_BADJPASS)
|| e.test((m_bPass != 0xFF && (m_bPass < m_jPass || m_bPass > m_numPasses)), E_BADBPASS)
|| e.test(m_aLig > 127, E_BADALIG))
{
releaseBuffers();
return face.error(e);
}
be::skip<uint32_t>(p, m_numPasses);
if (e.test(unsigned(p - silf_start) + sizeof(uint16_t) >= passes_start, E_BADPASSESSTART)) { releaseBuffers(); return face.error(e); }
m_numPseudo = be::read<uint16_t>(p);
be::skip<uint16_t>(p, 3); // searchPseudo, pseudoSelector, pseudoShift
m_pseudos = new Pseudo[m_numPseudo];
if (e.test(unsigned(p - silf_start) + m_numPseudo*(sizeof(uint32_t) + sizeof(uint16_t)) >= passes_start, E_BADNUMPSEUDO)
|| e.test(!m_pseudos, E_OUTOFMEM))
{
releaseBuffers(); return face.error(e);
}
for (int i = 0; i < m_numPseudo; i++)
{
m_pseudos[i].uid = be::read<uint32_t>(p);
m_pseudos[i].gid = be::read<uint16_t>(p);
}
const size_t clen = readClassMap(p, passes_start + silf_start - p, version, e);
m_passes = new Pass[m_numPasses];
if (e || e.test(clen > unsigned(passes_start + silf_start - p), E_BADPASSESSTART)
|| e.test(!m_passes, E_OUTOFMEM))
{ releaseBuffers(); return face.error(e); }
for (size_t i = 0; i < m_numPasses; ++i)
{
uint32_t pass_start = be::read<uint32_t>(o_passes);
uint32_t pass_end = be::peek<uint32_t>(o_passes);
face.error_context((face.error_context() & 0xFF00) + EC_ASILF + unsigned(i << 16));
if (e.test(pass_start > pass_end, E_BADPASSSTART)
|| e.test(pass_start < passes_start, E_BADPASSSTART)
|| e.test(pass_end > lSilf, E_BADPASSEND)) {
releaseBuffers(); return face.error(e);
}
enum passtype pt = PASS_TYPE_UNKNOWN;
if (i >= m_jPass) pt = PASS_TYPE_JUSTIFICATION;
else if (i >= m_pPass) pt = PASS_TYPE_POSITIONING;
else if (i >= m_sPass) pt = PASS_TYPE_SUBSTITUTE;
else pt = PASS_TYPE_LINEBREAK;
m_passes[i].init(this);
if (!m_passes[i].readPass(silf_start + pass_start, pass_end - pass_start, pass_start, face, pt,
version, e))
{
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_t Silf::readClassOffsets(const byte *&p, size_t data_len, Error &e)
{
const T cls_off = 2*sizeof(uint16_t) + sizeof(T)*(m_nClass+1);
const uint32_t max_off = (be::peek<T>(p + sizeof(T)*m_nClass) - cls_off)/sizeof(uint16_t);
// Check that the last+1 offset is less than or equal to the class map length.
if (e.test(be::peek<T>(p) != cls_off, E_MISALIGNEDCLASSES)
|| e.test(max_off > (data_len - cls_off)/sizeof(uint16_t), E_HIGHCLASSOFFSET))
return ERROROFFSET;
// Read in all the offsets.
m_classOffsets = gralloc<uint32_t>(m_nClass+1);
if (e.test(!m_classOffsets, E_OUTOFMEM)) return ERROROFFSET;
for (uint32_t * o = m_classOffsets, * const o_end = o + m_nClass + 1; o != o_end; ++o)
{
*o = (be::read<T>(p) - cls_off)/sizeof(uint16_t);
if (e.test(*o > max_off, E_HIGHCLASSOFFSET))
return ERROROFFSET;
}
return max_off;
}
size_t Silf::readClassMap(const byte *p, size_t data_len, uint32_t version, Error &e)
{
if (e.test(data_len < sizeof(uint16_t)*2, E_BADCLASSSIZE)) return ERROROFFSET;
m_nClass = be::read<uint16_t>(p);
m_nLinear = be::read<uint16_t>(p);
// Check that numLinear < numClass,
// that there is at least enough data for numClasses offsets.
if (e.test(m_nLinear > m_nClass, E_TOOMANYLINEAR)
|| e.test((m_nClass + 1) * (version >= 0x00040000 ? sizeof(uint32_t) : sizeof(uint16_t)) > (data_len - 4), E_CLASSESTOOBIG))
return ERROROFFSET;
uint32_t max_off;
if (version >= 0x00040000)
max_off = readClassOffsets<uint32_t>(p, data_len, e);
else
max_off = readClassOffsets<uint16_t>(p, data_len, e);
if (max_off == ERROROFFSET) return ERROROFFSET;
if (e.test((int)max_off < m_nLinear + (m_nClass - m_nLinear) * 6, E_CLASSESTOOBIG))
return ERROROFFSET;
// Check the linear offsets are sane, these must be monotonically increasing.
assert(m_nClass >= m_nLinear);
for (const uint32_t *o = m_classOffsets, * const o_end = o + m_nLinear; o != o_end; ++o)
if (e.test(o[0] > o[1], E_BADCLASSOFFSET))
return ERROROFFSET;
// Fortunately the class data is all uint16s so we can decode these now
m_classData = gralloc<uint16_t>(max_off);
if (e.test(!m_classData, E_OUTOFMEM)) return ERROROFFSET;
for (uint16_t *d = m_classData, * const d_end = d + max_off; d != d_end; ++d)
*d = be::read<uint16_t>(p);
// Check the lookup class invariants for each non-linear class
for (const uint32_t *o = m_classOffsets + m_nLinear, * const o_end = m_classOffsets + m_nClass; o != o_end; ++o)
{
const uint16_t * lookup = m_classData + *o;
if (e.test(*o + 4 > max_off, E_HIGHCLASSOFFSET) // LookupClass doesn't stretch over max_off
|| e.test(lookup[0] == 0 // A LookupClass with no looks is a suspicious thing ...
|| lookup[0] * 2 + *o + 4 > max_off // numIDs lookup pairs fits within (start of LookupClass' lookups array, max_off]
|| lookup[3] + lookup[1] != lookup[0], E_BADCLASSLOOKUPINFO) // rangeShift: numIDs - searchRange
|| e.test(((o[1] - *o) & 1) != 0, ERROROFFSET)) // glyphs are in pairs so difference must be even.
return ERROROFFSET;
}
return max_off;
}
uint16_t Silf::findPseudo(uint32_t uid) const
{
for (int i = 0; i < m_numPseudo; i++)
if (m_pseudos[i].uid == uid) return m_pseudos[i].gid;
return 0;
}
uint16_t Silf::findClassIndex(uint16_t cid, uint16_t gid) const
{
if (cid > m_nClass) return -1;
const uint16_t * 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] - m_classOffsets[cid]; i < n; ++i, ++cls)
if (*cls == gid) return i;
return -1;
}
else
{
const uint16_t * min = cls + 4, // lookups array
* max = min + cls[0]*2; // lookups aray is numIDs (cls[0]) uint16_t pairs long
do
{
const uint16_t * 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_t Silf::getClassGlyph(uint16_t cid, unsigned int index) const
{
if (cid > m_nClass) return 0;
uint32_t 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_t firstPass, uint8_t lastPass, int dobidi) const
{
size_t maxSize = seg.slotCount() * MAX_SEG_GROWTH_FACTOR;
ShapingContext ctxt(seg, m_dir, maxSize);
vm::Machine m(ctxt);
uint8_t lbidi = m_bPass;
#if !defined GRAPHITE2_NTRACING
json * const dbgout = seg.getFace()->logger();
#endif
if (lastPass == 0)
{
if (firstPass == lastPass && lbidi == 0xFF)
return true;
lastPass = m_numPasses;
}
if ((firstPass < lbidi || (dobidi && firstPass == lbidi)) && (lastPass >= lbidi || (dobidi && lastPass + 1 == lbidi)))
lastPass++;
else
lbidi = 0xFF;
for (size_t i = firstPass; i < lastPass; ++i)
{
// bidi and mirroring
if (i == lbidi)
{
#if !defined GRAPHITE2_NTRACING
if (dbgout)
{
*dbgout << json::item << json::object
// << "pindex" << i // for debugging
<< "id" << -1
<< "slotsdir" << (seg.currdir() ? "rtl" : "ltr")
<< "passdir" << (m_dir & 1 ? "rtl" : "ltr")
<< "slots" << json::array;
seg.positionSlots(nullptr, seg.slots().begin(), seg.slots().end(), seg.currdir());
for(auto & s: seg.slots())
*dbgout << dslot(&seg, &s);
*dbgout << json::close
<< "rules" << json::array << json::close
<< json::close;
}
#endif
if (seg.currdir() != (m_dir & 1))
seg.reverseSlots();
if (m_aMirror && (seg.dir() & 3) == 3)
seg.doMirror(m_aMirror);
--i;
lbidi = lastPass;
--lastPass;
continue;
}
#if !defined GRAPHITE2_NTRACING
if (dbgout)
{
*dbgout << json::item << json::object
// << "pindex" << i // for debugging
<< "id" << i+1
<< "slotsdir" << (seg.currdir() ? "rtl" : "ltr")
<< "passdir" << ((m_dir & 1) ^ m_passes[i].reverseDir() ? "rtl" : "ltr")
<< "slots" << json::array;
seg.positionSlots(nullptr, seg.slots().begin(), seg.slots().end(), seg.currdir());
for(auto & s: seg.slots())
*dbgout << dslot(&seg, &s);
*dbgout << json::close;
}
#endif
// test whether to reorder, prepare for positioning
bool reverse = (lbidi == 0xFF) && (seg.currdir() != ((m_dir & 1) ^ m_passes[i].reverseDir()));
if ((i >= 32 || (seg.passBits() & (1 << i)) == 0 || m_passes[i].collisionLoops())
&& !m_passes[i].runGraphite(m, ctxt, reverse))
return false;
// only subsitution passes can change segment length, cached subsegments are short for their text
if (m.status() != vm::Machine::finished
|| (seg.slotCount() && seg.slotCount() > maxSize))
return false;
}
return true;
}