The Tor Browser: gfx/graphite2/src/Justifier.cpp@b8a032363ba2

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 /*  GRAPHITE2 LICENSING

     3     Copyright 2012, SIL International

     4     All rights reserved.

     6     This library is free software; you can redistribute it and/or modify

     7     it under the terms of the GNU Lesser General Public License as published

     8     by the Free Software Foundation; either version 2.1 of License, or

     9     (at your option) any later version.

    11     This program is distributed in the hope that it will be useful,

    12     but WITHOUT ANY WARRANTY; without even the implied warranty of

    13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    14     Lesser General Public License for more details.

    16     You should also have received a copy of the GNU Lesser General Public

    17     License along with this library in the file named "LICENSE".

    18     If not, write to the Free Software Foundation, 51 Franklin Street,

    19     Suite 500, Boston, MA 02110-1335, USA or visit their web page on the

    20     internet at http://www.fsf.org/licenses/lgpl.html.

    22 Alternatively, the contents of this file may be used under the terms of the

    23 Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public

    24 License, as published by the Free Software Foundation, either version 2

    25 of the License or (at your option) any later version.

    26 */

    28 #include "inc/Segment.h"

    29 #include "graphite2/Font.h"

    30 #include "inc/debug.h"

    31 #include "inc/CharInfo.h"

    32 #include "inc/Slot.h"

    33 #include "inc/Main.h"

    34 #include <math.h>

    36 using namespace graphite2;

    38 class JustifyTotal {

    39 public:

    40     JustifyTotal() : m_numGlyphs(0), m_tStretch(0), m_tShrink(0), m_tStep(0), m_tWeight(0) {}

    41     void accumulate(Slot *s, Segment *seg, int level);

    42     int weight() const { return m_tWeight; }

    44     CLASS_NEW_DELETE

    46 private:

    47     int m_numGlyphs;

    48     int m_tStretch;

    49     int m_tShrink;

    50     int m_tStep;

    51     int m_tWeight;

    52 };

    54 void JustifyTotal::accumulate(Slot *s, Segment *seg, int level)

    55 {

    56     ++m_numGlyphs;

    57     m_tStretch += s->getJustify(seg, level, 0);

    58     m_tShrink += s->getJustify(seg, level, 1);

    59     m_tStep += s->getJustify(seg, level, 2);

    60     m_tWeight += s->getJustify(seg, level, 3);

    61 }

    63 float Segment::justify(Slot *pSlot, const Font *font, float width, GR_MAYBE_UNUSED justFlags flags, Slot *pFirst, Slot *pLast)

    64 {

    65     Slot *s, *end;

    66     float currWidth = 0.0;

    67     const float scale = font ? font->scale() : 1.0f;

    68     Position res;

    70     if (width < 0 && !(silf()->flags()))

    71         return width;

    73     if (!pFirst) pFirst = pSlot;

    74     while (!pFirst->isBase()) pFirst = pFirst->attachedTo();

    75     if (!pLast) pLast = last();

    76     while (!pLast->isBase()) pLast = pLast->attachedTo();

    77     const float base = pFirst->origin().x / scale;

    78     width = width / scale;

    79     if ((flags & gr_justEndInline) == 0)

    80     {

    81         do {

    82             Rect bbox = theGlyphBBoxTemporary(pLast->glyph());

    83             if (bbox.bl.x != 0. || bbox.bl.y != 0. || bbox.tr.x != 0. || bbox.tr.y == 0.)

    84                 break;

    85             pLast = pLast->prev();

    86         } while (pLast != pFirst);

    87     }

    89     end = pLast->nextSibling();

    90     pFirst = pFirst->nextSibling();

    92     int icount = 0;

    93     int numLevels = silf()->numJustLevels();

    94     if (!numLevels)

    95     {

    96         for (s = pSlot; s != end; s = s->next())

    97         {

    98             CharInfo *c = charinfo(s->before());

    99             if (isWhitespace(c->unicodeChar()))

   100             {

   101                 s->setJustify(this, 0, 3, 1);

   102                 s->setJustify(this, 0, 2, 1);

   103                 s->setJustify(this, 0, 0, -1);

   104                 ++icount;

   105             }

   106         }

   107         if (!icount)

   108         {

   109             for (s = pSlot; s != end; s = s->nextSibling())

   110             {

   111                 s->setJustify(this, 0, 3, 1);

   112                 s->setJustify(this, 0, 2, 1);

   113                 s->setJustify(this, 0, 0, -1);

   114             }

   115         }

   116         ++numLevels;

   117     }

   119     JustifyTotal *stats = new JustifyTotal[numLevels];

   120     if (!stats) return -1.0;

   121     for (s = pFirst; s != end; s = s->nextSibling())

   122     {

   123         float w = s->origin().x / scale + s->advance() - base;

   124         if (w > currWidth) currWidth = w;

   125         for (int j = 0; j < numLevels; ++j)

   126             stats[j].accumulate(s, this, j);

   127         s->just(0);

   128     }

   130     for (int i = (width < 0.0) ? -1 : numLevels - 1; i >= 0; --i)

   131     {

   132         float diff;

   133         float error = 0.;

   134         float diffpw;

   135         int tWeight = stats[i].weight();

   137         do {

   138             error = 0.;

   139             diff = width - currWidth;

   140             diffpw = diff / tWeight;

   141             tWeight = 0;

   142             for (s = pFirst; s != end; s = s->nextSibling()) // don't include final glyph

   143             {

   144                 int w = s->getJustify(this, i, 3);

   145                 float pref = diffpw * w + error;

   146                 int step = s->getJustify(this, i, 2);

   147                 if (!step) step = 1;        // handle lazy font developers

   148                 if (pref > 0)

   149                 {

   150                     float max = uint16(s->getJustify(this, i, 0));

   151                     if (i == 0) max -= s->just();

   152                     if (pref > max) pref = max;

   153                     else tWeight += w;

   154                 }

   155                 else

   156                 {

   157                     float max = uint16(s->getJustify(this, i, 1));

   158                     if (i == 0) max += s->just();

   159                     if (-pref > max) pref = -max;

   160                     else tWeight += w;

   161                 }

   162                 int actual = step ? int(pref / step) * step : int(pref);

   164                 if (actual)

   165                 {

   166                     error += diffpw * w - actual;

   167                     if (i == 0)

   168                         s->just(s->just() + actual);

   169                     else

   170                         s->setJustify(this, i, 4, actual);

   171                 }

   172             }

   173             currWidth += diff - error;

   174         } while (i == 0 && int(abs(error)) > 0 && tWeight);

   175     }

   177     Slot *oldFirst = m_first;

   178     Slot *oldLast = m_last;

   179     if (silf()->flags() & 1)

   180     {

   181         m_first = pSlot = addLineEnd(pSlot);

   182         m_last = pLast = addLineEnd(end);

   183         if (!m_first || !m_last) return -1.0;

   184     }

   185     else

   186     {

   187         m_first = pSlot;

   188         m_last = pLast;

   189     }

   191     // run justification passes here

   192 #if !defined GRAPHITE2_NTRACING

   193     json * const dbgout = m_face->logger();

   194     if (dbgout)

   195         *dbgout << json::object

   196                     << "justifies"  << objectid(this)

   197                     << "passes"     << json::array;

   198 #endif

   200     if (m_silf->justificationPass() != m_silf->positionPass() && (width >= 0. || (silf()->flags() & 1)))

   201         m_silf->runGraphite(this, m_silf->justificationPass(), m_silf->positionPass());

   203 #if !defined GRAPHITE2_NTRACING

   204     if (dbgout)

   205     {

   206         *dbgout     << json::item << json::close; // Close up the passes array

   207         positionSlots(NULL, pSlot, pLast);

   208         Slot *lEnd = pLast->nextSibling();

   209         *dbgout << "output" << json::array;

   210         for(Slot * t = pSlot; t != lEnd; t = t->next())

   211             *dbgout     << dslot(this, t);

   212         *dbgout         << json::close << json::close;

   213     }

   214 #endif

   216     res = positionSlots(font, pSlot, pLast);

   218     if (silf()->flags() & 1)

   219     {

   220         delLineEnd(m_first);

   221         delLineEnd(m_last);

   222     }

   223     m_first = oldFirst;

   224     m_last = oldLast;

   225     return res.x;

   226 }

   228 Slot *Segment::addLineEnd(Slot *nSlot)

   229 {

   230     Slot *eSlot = newSlot();

   231     if (!eSlot) return NULL;

   232     const uint16 gid = silf()->endLineGlyphid();

   233     const GlyphFace * theGlyph = m_face->glyphs().glyphSafe(gid);

   234     eSlot->setGlyph(this, gid, theGlyph);

   235     if (nSlot)

   236     {

   237         eSlot->next(nSlot);

   238         eSlot->prev(nSlot->prev());

   239         nSlot->prev(eSlot);

   240         eSlot->before(nSlot->before());

   241         if (eSlot->prev())

   242             eSlot->after(eSlot->prev()->after());

   243         else

   244             eSlot->after(nSlot->before());

   245     }

   246     else

   247     {

   248         nSlot = m_last;

   249         eSlot->prev(nSlot);

   250         nSlot->next(eSlot);

   251         eSlot->after(eSlot->prev()->after());

   252         eSlot->before(nSlot->after());

   253     }

   254     return eSlot;

   255 }

   257 void Segment::delLineEnd(Slot *s)

   258 {

   259     Slot *nSlot = s->next();

   260     if (nSlot)

   261     {

   262         nSlot->prev(s->prev());

   263         if (s->prev())

   264             s->prev()->next(nSlot);

   265     }

   266     else

   267         s->prev()->next(NULL);

   268     freeSlot(s);

   269 }

The Tor Browser / file revision

gfx/graphite2/src/Justifier.cpp@b8a032363ba2

gfx/graphite2/src/Justifier.cpp