gfx/graphite2/src/Justifier.cpp

Wed, 31 Dec 2014 06:09:35 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Wed, 31 Dec 2014 06:09:35 +0100
changeset 0
6474c204b198
permissions
-rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     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 }

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