1/***************************************************************************/
2/*                                                                         */
3/*  pshints.c                                                              */
4/*                                                                         */
5/*    Adobe's code for handling CFF hints (body).                          */
6/*                                                                         */
7/*  Copyright 2007-2014 Adobe Systems Incorporated.                        */
8/*                                                                         */
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35/*                                                                         */
36/***************************************************************************/
37
38
39#include "psft.h"
40#include FT_INTERNAL_DEBUG_H
41
42#include "psglue.h"
43#include "psfont.h"
44#include "pshints.h"
45#include "psintrp.h"
46
47
48  /*************************************************************************/
49  /*                                                                       */
50  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
51  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
52  /* messages during execution.                                            */
53  /*                                                                       */
54#undef  FT_COMPONENT
55#define FT_COMPONENT  trace_cf2hints
56
57
58  typedef struct  CF2_HintMoveRec_
59  {
60    size_t     j;          /* index of upper hint map edge   */
61    CF2_Fixed  moveUp;     /* adjustment to optimum position */
62
63  } CF2_HintMoveRec, *CF2_HintMove;
64
65
66  /* Compute angular momentum for winding order detection.  It is called */
67  /* for all lines and curves, but not necessarily in element order.     */
68  static CF2_Int
69  cf2_getWindingMomentum( CF2_Fixed  x1,
70                          CF2_Fixed  y1,
71                          CF2_Fixed  x2,
72                          CF2_Fixed  y2 )
73  {
74    /* cross product of pt1 position from origin with pt2 position from  */
75    /* pt1; we reduce the precision so that the result fits into 32 bits */
76
77    return ( x1 >> 16 ) * ( SUB_INT32( y2, y1 ) >> 16 ) -
78           ( y1 >> 16 ) * ( SUB_INT32( x2, x1 ) >> 16 );
79  }
80
81
82  /*
83   * Construct from a StemHint; this is used as a parameter to
84   * `cf2_blues_capture'.
85   * `hintOrigin' is the character space displacement of a seac accent.
86   * Adjust stem hint for darkening here.
87   *
88   */
89  static void
90  cf2_hint_init( CF2_Hint            hint,
91                 const CF2_ArrStack  stemHintArray,
92                 size_t              indexStemHint,
93                 const CF2_Font      font,
94                 CF2_Fixed           hintOrigin,
95                 CF2_Fixed           scale,
96                 FT_Bool             bottom )
97  {
98    CF2_Fixed               width;
99    const CF2_StemHintRec*  stemHint;
100
101
102    FT_ZERO( hint );
103
104    stemHint = (const CF2_StemHintRec*)cf2_arrstack_getPointer(
105                                         stemHintArray,
106                                         indexStemHint );
107
108    width = SUB_INT32( stemHint->max, stemHint->min );
109
110    if ( width == cf2_intToFixed( -21 ) )
111    {
112      /* ghost bottom */
113
114      if ( bottom )
115      {
116        hint->csCoord = stemHint->max;
117        hint->flags   = CF2_GhostBottom;
118      }
119      else
120        hint->flags = 0;
121    }
122
123    else if ( width == cf2_intToFixed( -20 ) )
124    {
125      /* ghost top */
126
127      if ( bottom )
128        hint->flags = 0;
129      else
130      {
131        hint->csCoord = stemHint->min;
132        hint->flags   = CF2_GhostTop;
133      }
134    }
135
136    else if ( width < 0 )
137    {
138      /* inverted pair */
139
140      /*
141       * Hints with negative widths were produced by an early version of a
142       * non-Adobe font tool.  The Type 2 spec allows edge (ghost) hints
143       * with negative widths, but says
144       *
145       *   All other negative widths have undefined meaning.
146       *
147       * CoolType has a silent workaround that negates the hint width; for
148       * permissive mode, we do the same here.
149       *
150       * Note: Such fonts cannot use ghost hints, but should otherwise work.
151       * Note: Some poor hints in our faux fonts can produce negative
152       *       widths at some blends.  For example, see a light weight of
153       *       `u' in ASerifMM.
154       *
155       */
156      if ( bottom )
157      {
158        hint->csCoord = stemHint->max;
159        hint->flags   = CF2_PairBottom;
160      }
161      else
162      {
163        hint->csCoord = stemHint->min;
164        hint->flags   = CF2_PairTop;
165      }
166    }
167
168    else
169    {
170      /* normal pair */
171
172      if ( bottom )
173      {
174        hint->csCoord = stemHint->min;
175        hint->flags   = CF2_PairBottom;
176      }
177      else
178      {
179        hint->csCoord = stemHint->max;
180        hint->flags   = CF2_PairTop;
181      }
182    }
183
184    /* Now that ghost hints have been detected, adjust this edge for      */
185    /* darkening.  Bottoms are not changed; tops are incremented by twice */
186    /* `darkenY'.                                                         */
187    if ( cf2_hint_isTop( hint ) )
188      hint->csCoord = ADD_INT32( hint->csCoord, 2 * font->darkenY );
189
190    hint->csCoord = ADD_INT32( hint->csCoord, hintOrigin );
191    hint->scale   = scale;
192    hint->index   = indexStemHint;   /* index in original stem hint array */
193
194    /* if original stem hint has been used, use the same position */
195    if ( hint->flags != 0 && stemHint->used )
196    {
197      if ( cf2_hint_isTop( hint ) )
198        hint->dsCoord = stemHint->maxDS;
199      else
200        hint->dsCoord = stemHint->minDS;
201
202      cf2_hint_lock( hint );
203    }
204    else
205      hint->dsCoord = FT_MulFix( hint->csCoord, scale );
206  }
207
208
209  /* initialize an invalid hint map element */
210  static void
211  cf2_hint_initZero( CF2_Hint  hint )
212  {
213    FT_ZERO( hint );
214  }
215
216
217  FT_LOCAL_DEF( FT_Bool )
218  cf2_hint_isValid( const CF2_Hint  hint )
219  {
220    return (FT_Bool)( hint->flags != 0 );
221  }
222
223
224  static FT_Bool
225  cf2_hint_isPair( const CF2_Hint  hint )
226  {
227    return (FT_Bool)( ( hint->flags                      &
228                        ( CF2_PairBottom | CF2_PairTop ) ) != 0 );
229  }
230
231
232  static FT_Bool
233  cf2_hint_isPairTop( const CF2_Hint  hint )
234  {
235    return (FT_Bool)( ( hint->flags & CF2_PairTop ) != 0 );
236  }
237
238
239  FT_LOCAL_DEF( FT_Bool )
240  cf2_hint_isTop( const CF2_Hint  hint )
241  {
242    return (FT_Bool)( ( hint->flags                    &
243                        ( CF2_PairTop | CF2_GhostTop ) ) != 0 );
244  }
245
246
247  FT_LOCAL_DEF( FT_Bool )
248  cf2_hint_isBottom( const CF2_Hint  hint )
249  {
250    return (FT_Bool)( ( hint->flags                          &
251                        ( CF2_PairBottom | CF2_GhostBottom ) ) != 0 );
252  }
253
254
255  static FT_Bool
256  cf2_hint_isLocked( const CF2_Hint  hint )
257  {
258    return (FT_Bool)( ( hint->flags & CF2_Locked ) != 0 );
259  }
260
261
262  static FT_Bool
263  cf2_hint_isSynthetic( const CF2_Hint  hint )
264  {
265    return (FT_Bool)( ( hint->flags & CF2_Synthetic ) != 0 );
266  }
267
268
269  FT_LOCAL_DEF( void )
270  cf2_hint_lock( CF2_Hint  hint )
271  {
272    hint->flags |= CF2_Locked;
273  }
274
275
276  FT_LOCAL_DEF( void )
277  cf2_hintmap_init( CF2_HintMap   hintmap,
278                    CF2_Font      font,
279                    CF2_HintMap   initialMap,
280                    CF2_ArrStack  hintMoves,
281                    CF2_Fixed     scale )
282  {
283    FT_ZERO( hintmap );
284
285    /* copy parameters from font instance */
286    hintmap->hinted         = font->hinted;
287    hintmap->scale          = scale;
288    hintmap->font           = font;
289    hintmap->initialHintMap = initialMap;
290    /* will clear in `cf2_hintmap_adjustHints' */
291    hintmap->hintMoves      = hintMoves;
292  }
293
294
295  static FT_Bool
296  cf2_hintmap_isValid( const CF2_HintMap  hintmap )
297  {
298    return hintmap->isValid;
299  }
300
301
302  static void
303  cf2_hintmap_dump( CF2_HintMap  hintmap )
304  {
305#ifdef FT_DEBUG_LEVEL_TRACE
306    CF2_UInt  i;
307
308
309    FT_TRACE6(( "  index  csCoord  dsCoord  scale  flags\n" ));
310
311    for ( i = 0; i < hintmap->count; i++ )
312    {
313      CF2_Hint  hint = &hintmap->edge[i];
314
315
316      FT_TRACE6(( "  %3d    %7.2f  %7.2f  %5d  %s%s%s%s\n",
317                  hint->index,
318                  hint->csCoord / 65536.0,
319                  hint->dsCoord / ( hint->scale * 1.0 ),
320                  hint->scale,
321                  ( cf2_hint_isPair( hint ) ? "p" : "g" ),
322                  ( cf2_hint_isTop( hint ) ? "t" : "b" ),
323                  ( cf2_hint_isLocked( hint ) ? "L" : ""),
324                  ( cf2_hint_isSynthetic( hint ) ? "S" : "" ) ));
325    }
326#else
327    FT_UNUSED( hintmap );
328#endif
329  }
330
331
332  /* transform character space coordinate to device space using hint map */
333  static CF2_Fixed
334  cf2_hintmap_map( CF2_HintMap  hintmap,
335                   CF2_Fixed    csCoord )
336  {
337    if ( hintmap->count == 0 || ! hintmap->hinted )
338    {
339      /* there are no hints; use uniform scale and zero offset */
340      return FT_MulFix( csCoord, hintmap->scale );
341    }
342    else
343    {
344      /* start linear search from last hit */
345      CF2_UInt  i = hintmap->lastIndex;
346
347
348      FT_ASSERT( hintmap->lastIndex < CF2_MAX_HINT_EDGES );
349
350      /* search up */
351      while ( i < hintmap->count - 1                  &&
352              csCoord >= hintmap->edge[i + 1].csCoord )
353        i += 1;
354
355      /* search down */
356      while ( i > 0 && csCoord < hintmap->edge[i].csCoord )
357        i -= 1;
358
359      hintmap->lastIndex = i;
360
361      if ( i == 0 && csCoord < hintmap->edge[0].csCoord )
362      {
363        /* special case for points below first edge: use uniform scale */
364        return ADD_INT32( FT_MulFix( SUB_INT32( csCoord,
365                                                hintmap->edge[0].csCoord ),
366                                     hintmap->scale ),
367                          hintmap->edge[0].dsCoord );
368      }
369      else
370      {
371        /*
372         * Note: entries with duplicate csCoord are allowed.
373         * Use edge[i], the highest entry where csCoord >= entry[i].csCoord
374         */
375        return ADD_INT32( FT_MulFix( SUB_INT32( csCoord,
376                                                hintmap->edge[i].csCoord ),
377                                     hintmap->edge[i].scale ),
378                          hintmap->edge[i].dsCoord );
379      }
380    }
381  }
382
383
384  /*
385   * This hinting policy moves a hint pair in device space so that one of
386   * its two edges is on a device pixel boundary (its fractional part is
387   * zero).  `cf2_hintmap_insertHint' guarantees no overlap in CS
388   * space.  Ensure here that there is no overlap in DS.
389   *
390   * In the first pass, edges are adjusted relative to adjacent hints.
391   * Those that are below have already been adjusted.  Those that are
392   * above have not yet been adjusted.  If a hint above blocks an
393   * adjustment to an optimal position, we will try again in a second
394   * pass.  The second pass is top-down.
395   *
396   */
397
398  static void
399  cf2_hintmap_adjustHints( CF2_HintMap  hintmap )
400  {
401    size_t  i, j;
402
403
404    cf2_arrstack_clear( hintmap->hintMoves );      /* working storage */
405
406    /*
407     * First pass is bottom-up (font hint order) without look-ahead.
408     * Locked edges are already adjusted.
409     * Unlocked edges begin with dsCoord from `initialHintMap'.
410     * Save edges that are not optimally adjusted in `hintMoves' array,
411     * and process them in second pass.
412     */
413
414    for ( i = 0; i < hintmap->count; i++ )
415    {
416      FT_Bool  isPair = cf2_hint_isPair( &hintmap->edge[i] );
417
418
419      /* index of upper edge (same value for ghost hint) */
420      j = isPair ? i + 1 : i;
421
422      FT_ASSERT( j < hintmap->count );
423      FT_ASSERT( cf2_hint_isValid( &hintmap->edge[i] ) );
424      FT_ASSERT( cf2_hint_isValid( &hintmap->edge[j] ) );
425      FT_ASSERT( cf2_hint_isLocked( &hintmap->edge[i] ) ==
426                   cf2_hint_isLocked( &hintmap->edge[j] ) );
427
428      if ( !cf2_hint_isLocked( &hintmap->edge[i] ) )
429      {
430        /* hint edge is not locked, we can adjust it */
431        CF2_Fixed  fracDown = cf2_fixedFraction( hintmap->edge[i].dsCoord );
432        CF2_Fixed  fracUp   = cf2_fixedFraction( hintmap->edge[j].dsCoord );
433
434        /* calculate all four possibilities; moves down are negative */
435        CF2_Fixed  downMoveDown = 0 - fracDown;
436        CF2_Fixed  upMoveDown   = 0 - fracUp;
437        CF2_Fixed  downMoveUp   = ( fracDown == 0 )
438                                    ? 0
439                                    : cf2_intToFixed( 1 ) - fracDown;
440        CF2_Fixed  upMoveUp     = ( fracUp == 0 )
441                                    ? 0
442                                    : cf2_intToFixed( 1 ) - fracUp;
443
444        /* smallest move up */
445        CF2_Fixed  moveUp   = FT_MIN( downMoveUp, upMoveUp );
446        /* smallest move down */
447        CF2_Fixed  moveDown = FT_MAX( downMoveDown, upMoveDown );
448
449        /* final amount to move edge or edge pair */
450        CF2_Fixed  move;
451
452        CF2_Fixed  downMinCounter = CF2_MIN_COUNTER;
453        CF2_Fixed  upMinCounter   = CF2_MIN_COUNTER;
454        FT_Bool    saveEdge       = FALSE;
455
456
457        /* minimum counter constraint doesn't apply when adjacent edges */
458        /* are synthetic                                                */
459        /* TODO: doesn't seem a big effect; for now, reduce the code    */
460#if 0
461        if ( i == 0                                        ||
462             cf2_hint_isSynthetic( &hintmap->edge[i - 1] ) )
463          downMinCounter = 0;
464
465        if ( j >= hintmap->count - 1                       ||
466             cf2_hint_isSynthetic( &hintmap->edge[j + 1] ) )
467          upMinCounter = 0;
468#endif
469
470        /* is there room to move up?                                    */
471        /* there is if we are at top of array or the next edge is at or */
472        /* beyond proposed move up?                                     */
473        if ( j >= hintmap->count - 1                ||
474             hintmap->edge[j + 1].dsCoord >=
475               ADD_INT32( hintmap->edge[j].dsCoord,
476                          moveUp + upMinCounter )   )
477        {
478          /* there is room to move up; is there also room to move down? */
479          if ( i == 0                                   ||
480               hintmap->edge[i - 1].dsCoord <=
481                 ADD_INT32( hintmap->edge[i].dsCoord,
482                            moveDown - downMinCounter ) )
483          {
484            /* move smaller absolute amount */
485            move = ( -moveDown < moveUp ) ? moveDown : moveUp;  /* optimum */
486          }
487          else
488            move = moveUp;
489        }
490        else
491        {
492          /* is there room to move down? */
493          if ( i == 0                                   ||
494               hintmap->edge[i - 1].dsCoord <=
495                 ADD_INT32( hintmap->edge[i].dsCoord,
496                            moveDown - downMinCounter ) )
497          {
498            move     = moveDown;
499            /* true if non-optimum move */
500            saveEdge = (FT_Bool)( moveUp < -moveDown );
501          }
502          else
503          {
504            /* no room to move either way without overlapping or reducing */
505            /* the counter too much                                       */
506            move     = 0;
507            saveEdge = TRUE;
508          }
509        }
510
511        /* Identify non-moves and moves down that aren't optimal, and save */
512        /* them for second pass.                                           */
513        /* Do this only if there is an unlocked edge above (which could    */
514        /* possibly move).                                                 */
515        if ( saveEdge                                    &&
516             j < hintmap->count - 1                      &&
517             !cf2_hint_isLocked( &hintmap->edge[j + 1] ) )
518        {
519          CF2_HintMoveRec  savedMove;
520
521
522          savedMove.j      = j;
523          /* desired adjustment in second pass */
524          savedMove.moveUp = moveUp - move;
525
526          cf2_arrstack_push( hintmap->hintMoves, &savedMove );
527        }
528
529        /* move the edge(s) */
530        hintmap->edge[i].dsCoord = ADD_INT32( hintmap->edge[i].dsCoord,
531                                              move );
532        if ( isPair )
533          hintmap->edge[j].dsCoord = ADD_INT32( hintmap->edge[j].dsCoord,
534                                                move );
535      }
536
537      /* assert there are no overlaps in device space */
538      FT_ASSERT( i == 0                                                   ||
539                 hintmap->edge[i - 1].dsCoord <= hintmap->edge[i].dsCoord );
540      FT_ASSERT( i < j                                                ||
541                 hintmap->edge[i].dsCoord <= hintmap->edge[j].dsCoord );
542
543      /* adjust the scales, avoiding divide by zero */
544      if ( i > 0 )
545      {
546        if ( hintmap->edge[i].csCoord != hintmap->edge[i - 1].csCoord )
547          hintmap->edge[i - 1].scale =
548            FT_DivFix( SUB_INT32( hintmap->edge[i].dsCoord,
549                                  hintmap->edge[i - 1].dsCoord ),
550                       SUB_INT32( hintmap->edge[i].csCoord,
551                                  hintmap->edge[i - 1].csCoord ) );
552      }
553
554      if ( isPair )
555      {
556        if ( hintmap->edge[j].csCoord != hintmap->edge[j - 1].csCoord )
557          hintmap->edge[j - 1].scale =
558            FT_DivFix( SUB_INT32( hintmap->edge[j].dsCoord,
559                                  hintmap->edge[j - 1].dsCoord ),
560                       SUB_INT32( hintmap->edge[j].csCoord,
561                                  hintmap->edge[j - 1].csCoord ) );
562
563        i += 1;     /* skip upper edge on next loop */
564      }
565    }
566
567    /* second pass tries to move non-optimal hints up, in case there is */
568    /* room now                                                         */
569    for ( i = cf2_arrstack_size( hintmap->hintMoves ); i > 0; i-- )
570    {
571      CF2_HintMove  hintMove = (CF2_HintMove)
572                      cf2_arrstack_getPointer( hintmap->hintMoves, i - 1 );
573
574
575      j = hintMove->j;
576
577      /* this was tested before the push, above */
578      FT_ASSERT( j < hintmap->count - 1 );
579
580      /* is there room to move up? */
581      if ( hintmap->edge[j + 1].dsCoord >=
582             ADD_INT32( hintmap->edge[j].dsCoord,
583                        hintMove->moveUp + CF2_MIN_COUNTER ) )
584      {
585        /* there is more room now, move edge up */
586        hintmap->edge[j].dsCoord = ADD_INT32( hintmap->edge[j].dsCoord,
587                                              hintMove->moveUp );
588
589        if ( cf2_hint_isPair( &hintmap->edge[j] ) )
590        {
591          FT_ASSERT( j > 0 );
592          hintmap->edge[j - 1].dsCoord =
593            ADD_INT32( hintmap->edge[j - 1].dsCoord, hintMove->moveUp );
594        }
595      }
596    }
597  }
598
599
600  /* insert hint edges into map, sorted by csCoord */
601  static void
602  cf2_hintmap_insertHint( CF2_HintMap  hintmap,
603                          CF2_Hint     bottomHintEdge,
604                          CF2_Hint     topHintEdge )
605  {
606    CF2_UInt  indexInsert;
607
608    /* set default values, then check for edge hints */
609    FT_Bool   isPair         = TRUE;
610    CF2_Hint  firstHintEdge  = bottomHintEdge;
611    CF2_Hint  secondHintEdge = topHintEdge;
612
613
614    /* one or none of the input params may be invalid when dealing with */
615    /* edge hints; at least one edge must be valid                      */
616    FT_ASSERT( cf2_hint_isValid( bottomHintEdge ) ||
617               cf2_hint_isValid( topHintEdge )    );
618
619    /* determine how many and which edges to insert */
620    if ( !cf2_hint_isValid( bottomHintEdge ) )
621    {
622      /* insert only the top edge */
623      firstHintEdge = topHintEdge;
624      isPair        = FALSE;
625    }
626    else if ( !cf2_hint_isValid( topHintEdge ) )
627    {
628      /* insert only the bottom edge */
629      isPair = FALSE;
630    }
631
632    /* paired edges must be in proper order */
633    if ( isPair                                         &&
634         topHintEdge->csCoord < bottomHintEdge->csCoord )
635      return;
636
637    /* linear search to find index value of insertion point */
638    indexInsert = 0;
639    for ( ; indexInsert < hintmap->count; indexInsert++ )
640    {
641      if ( hintmap->edge[indexInsert].csCoord >= firstHintEdge->csCoord )
642        break;
643    }
644
645    FT_TRACE7(( "  Got hint at %.2f (%.2f)\n",
646                firstHintEdge->csCoord / 65536.0,
647                firstHintEdge->dsCoord / 65536.0 ));
648    if ( isPair )
649      FT_TRACE7(( "  Got hint at %.2f (%.2f)\n",
650                  secondHintEdge->csCoord / 65536.0,
651                  secondHintEdge->dsCoord / 65536.0 ));
652
653    /*
654     * Discard any hints that overlap in character space.  Most often, this
655     * is while building the initial map, where captured hints from all
656     * zones are combined.  Define overlap to include hints that `touch'
657     * (overlap zero).  Hiragino Sans/Gothic fonts have numerous hints that
658     * touch.  Some fonts have non-ideographic glyphs that overlap our
659     * synthetic hints.
660     *
661     * Overlap also occurs when darkening stem hints that are close.
662     *
663     */
664    if ( indexInsert < hintmap->count )
665    {
666      /* we are inserting before an existing edge:    */
667      /* verify that an existing edge is not the same */
668      if ( hintmap->edge[indexInsert].csCoord == firstHintEdge->csCoord )
669        return; /* ignore overlapping stem hint */
670
671      /* verify that a new pair does not straddle the next edge */
672      if ( isPair                                                        &&
673           hintmap->edge[indexInsert].csCoord <= secondHintEdge->csCoord )
674        return; /* ignore overlapping stem hint */
675
676      /* verify that we are not inserting between paired edges */
677      if ( cf2_hint_isPairTop( &hintmap->edge[indexInsert] ) )
678        return; /* ignore overlapping stem hint */
679    }
680
681    /* recompute device space locations using initial hint map */
682    if ( cf2_hintmap_isValid( hintmap->initialHintMap ) &&
683         !cf2_hint_isLocked( firstHintEdge )            )
684    {
685      if ( isPair )
686      {
687        /* Use hint map to position the center of stem, and nominal scale */
688        /* to position the two edges.  This preserves the stem width.     */
689        CF2_Fixed  midpoint =
690                     cf2_hintmap_map(
691                       hintmap->initialHintMap,
692                       ADD_INT32( secondHintEdge->csCoord,
693                                  firstHintEdge->csCoord ) / 2 );
694        CF2_Fixed  halfWidth =
695                     FT_MulFix( SUB_INT32( secondHintEdge->csCoord,
696                                           firstHintEdge->csCoord ) / 2,
697                                hintmap->scale );
698
699
700        firstHintEdge->dsCoord  = SUB_INT32( midpoint, halfWidth );
701        secondHintEdge->dsCoord = ADD_INT32( midpoint, halfWidth );
702      }
703      else
704        firstHintEdge->dsCoord = cf2_hintmap_map( hintmap->initialHintMap,
705                                                  firstHintEdge->csCoord );
706    }
707
708    /*
709     * Discard any hints that overlap in device space; this can occur
710     * because locked hints have been moved to align with blue zones.
711     *
712     * TODO: Although we might correct this later during adjustment, we
713     * don't currently have a way to delete a conflicting hint once it has
714     * been inserted.  See v2.030 MinionPro-Regular, 12 ppem darkened,
715     * initial hint map for second path, glyph 945 (the perispomeni (tilde)
716     * in U+1F6E, Greek omega with psili and perispomeni).  Darkening is
717     * 25.  Pair 667,747 initially conflicts in design space with top edge
718     * 660.  This is because 667 maps to 7.87, and the top edge was
719     * captured by a zone at 8.0.  The pair is later successfully inserted
720     * in a zone without the top edge.  In this zone it is adjusted to 8.0,
721     * and no longer conflicts with the top edge in design space.  This
722     * means it can be included in yet a later zone which does have the top
723     * edge hint.  This produces a small mismatch between the first and
724     * last points of this path, even though the hint masks are the same.
725     * The density map difference is tiny (1/256).
726     *
727     */
728
729    if ( indexInsert > 0 )
730    {
731      /* we are inserting after an existing edge */
732      if ( firstHintEdge->dsCoord < hintmap->edge[indexInsert - 1].dsCoord )
733        return;
734    }
735
736    if ( indexInsert < hintmap->count )
737    {
738      /* we are inserting before an existing edge */
739      if ( isPair )
740      {
741        if ( secondHintEdge->dsCoord > hintmap->edge[indexInsert].dsCoord )
742          return;
743      }
744      else
745      {
746        if ( firstHintEdge->dsCoord > hintmap->edge[indexInsert].dsCoord )
747          return;
748      }
749    }
750
751    /* make room to insert */
752    {
753      CF2_UInt  iSrc = hintmap->count - 1;
754      CF2_UInt  iDst = isPair ? hintmap->count + 1 : hintmap->count;
755
756      CF2_UInt  count = hintmap->count - indexInsert;
757
758
759      if ( iDst >= CF2_MAX_HINT_EDGES )
760      {
761        FT_TRACE4(( "cf2_hintmap_insertHint: too many hintmaps\n" ));
762        return;
763      }
764
765      while ( count-- )
766        hintmap->edge[iDst--] = hintmap->edge[iSrc--];
767
768      /* insert first edge */
769      hintmap->edge[indexInsert] = *firstHintEdge;         /* copy struct */
770      hintmap->count            += 1;
771
772      FT_TRACE7(( "  Inserting hint %.2f (%.2f)\n",
773                  firstHintEdge->csCoord / 65536.0,
774                  firstHintEdge->dsCoord / 65536.0 ));
775
776      if ( isPair )
777      {
778        /* insert second edge */
779        hintmap->edge[indexInsert + 1] = *secondHintEdge;  /* copy struct */
780        hintmap->count                += 1;
781
782        FT_TRACE7(( "  Inserting hint %.2f (%.2f)\n",
783                    secondHintEdge->csCoord / 65536.0,
784                    secondHintEdge->dsCoord / 65536.0 ));
785
786      }
787    }
788
789    return;
790  }
791
792
793  /*
794   * Build a map from hints and mask.
795   *
796   * This function may recur one level if `hintmap->initialHintMap' is not yet
797   * valid.
798   * If `initialMap' is true, simply build initial map.
799   *
800   * Synthetic hints are used in two ways.  A hint at zero is inserted, if
801   * needed, in the initial hint map, to prevent translations from
802   * propagating across the origin.  If synthetic em box hints are enabled
803   * for ideographic dictionaries, then they are inserted in all hint
804   * maps, including the initial one.
805   *
806   */
807  FT_LOCAL_DEF( void )
808  cf2_hintmap_build( CF2_HintMap   hintmap,
809                     CF2_ArrStack  hStemHintArray,
810                     CF2_ArrStack  vStemHintArray,
811                     CF2_HintMask  hintMask,
812                     CF2_Fixed     hintOrigin,
813                     FT_Bool       initialMap )
814  {
815    FT_Byte*  maskPtr;
816
817    CF2_Font         font = hintmap->font;
818    CF2_HintMaskRec  tempHintMask;
819
820    size_t   bitCount, i;
821    FT_Byte  maskByte;
822
823
824    /* check whether initial map is constructed */
825    if ( !initialMap && !cf2_hintmap_isValid( hintmap->initialHintMap ) )
826    {
827      /* make recursive call with initialHintMap and temporary mask; */
828      /* temporary mask will get all bits set, below */
829      cf2_hintmask_init( &tempHintMask, hintMask->error );
830      cf2_hintmap_build( hintmap->initialHintMap,
831                         hStemHintArray,
832                         vStemHintArray,
833                         &tempHintMask,
834                         hintOrigin,
835                         TRUE );
836    }
837
838    if ( !cf2_hintmask_isValid( hintMask ) )
839    {
840      /* without a hint mask, assume all hints are active */
841      cf2_hintmask_setAll( hintMask,
842                           cf2_arrstack_size( hStemHintArray ) +
843                             cf2_arrstack_size( vStemHintArray ) );
844      if ( !cf2_hintmask_isValid( hintMask ) )
845      {
846        if ( font->isT1 )
847        {
848          /* no error, just continue unhinted */
849          *hintMask->error = FT_Err_Ok;
850          hintmap->hinted  = FALSE;
851        }
852        return;                   /* too many stem hints */
853      }
854    }
855
856    /* begin by clearing the map */
857    hintmap->count     = 0;
858    hintmap->lastIndex = 0;
859
860    /* make a copy of the hint mask so we can modify it */
861    tempHintMask = *hintMask;
862    maskPtr      = cf2_hintmask_getMaskPtr( &tempHintMask );
863
864    /* use the hStem hints only, which are first in the mask */
865    bitCount = cf2_arrstack_size( hStemHintArray );
866
867    /* Defense-in-depth.  Should never return here. */
868    if ( bitCount > hintMask->bitCount )
869      return;
870
871    /* synthetic embox hints get highest priority */
872    if ( font->blues.doEmBoxHints )
873    {
874      CF2_HintRec  dummy;
875
876
877      cf2_hint_initZero( &dummy );   /* invalid hint map element */
878
879      /* ghost bottom */
880      cf2_hintmap_insertHint( hintmap,
881                              &font->blues.emBoxBottomEdge,
882                              &dummy );
883      /* ghost top */
884      cf2_hintmap_insertHint( hintmap,
885                              &dummy,
886                              &font->blues.emBoxTopEdge );
887    }
888
889    /* insert hints captured by a blue zone or already locked (higher */
890    /* priority)                                                      */
891    for ( i = 0, maskByte = 0x80; i < bitCount; i++ )
892    {
893      if ( maskByte & *maskPtr )
894      {
895        /* expand StemHint into two `CF2_Hint' elements */
896        CF2_HintRec  bottomHintEdge, topHintEdge;
897
898
899        cf2_hint_init( &bottomHintEdge,
900                       hStemHintArray,
901                       i,
902                       font,
903                       hintOrigin,
904                       hintmap->scale,
905                       TRUE /* bottom */ );
906        cf2_hint_init( &topHintEdge,
907                       hStemHintArray,
908                       i,
909                       font,
910                       hintOrigin,
911                       hintmap->scale,
912                       FALSE /* top */ );
913
914        if ( cf2_hint_isLocked( &bottomHintEdge ) ||
915             cf2_hint_isLocked( &topHintEdge )    ||
916             cf2_blues_capture( &font->blues,
917                                &bottomHintEdge,
918                                &topHintEdge )   )
919        {
920          /* insert captured hint into map */
921          cf2_hintmap_insertHint( hintmap, &bottomHintEdge, &topHintEdge );
922
923          *maskPtr &= ~maskByte;      /* turn off the bit for this hint */
924        }
925      }
926
927      if ( ( i & 7 ) == 7 )
928      {
929        /* move to next mask byte */
930        maskPtr++;
931        maskByte = 0x80;
932      }
933      else
934        maskByte >>= 1;
935    }
936
937    /* initial hint map includes only captured hints plus maybe one at 0 */
938
939    /*
940     * TODO: There is a problem here because we are trying to build a
941     *       single hint map containing all captured hints.  It is
942     *       possible for there to be conflicts between captured hints,
943     *       either because of darkening or because the hints are in
944     *       separate hint zones (we are ignoring hint zones for the
945     *       initial map).  An example of the latter is MinionPro-Regular
946     *       v2.030 glyph 883 (Greek Capital Alpha with Psili) at 15ppem.
947     *       A stem hint for the psili conflicts with the top edge hint
948     *       for the base character.  The stem hint gets priority because
949     *       of its sort order.  In glyph 884 (Greek Capital Alpha with
950     *       Psili and Oxia), the top of the base character gets a stem
951     *       hint, and the psili does not.  This creates different initial
952     *       maps for the two glyphs resulting in different renderings of
953     *       the base character.  Will probably defer this either as not
954     *       worth the cost or as a font bug.  I don't think there is any
955     *       good reason for an accent to be captured by an alignment
956     *       zone.  -darnold 2/12/10
957     */
958
959    if ( initialMap )
960    {
961      /* Apply a heuristic that inserts a point for (0,0), unless it's     */
962      /* already covered by a mapping.  This locks the baseline for glyphs */
963      /* that have no baseline hints.                                      */
964
965      if ( hintmap->count == 0                           ||
966           hintmap->edge[0].csCoord > 0                  ||
967           hintmap->edge[hintmap->count - 1].csCoord < 0 )
968      {
969        /* all edges are above 0 or all edges are below 0; */
970        /* construct a locked edge hint at 0               */
971
972        CF2_HintRec  edge, invalid;
973
974
975        cf2_hint_initZero( &edge );
976
977        edge.flags = CF2_GhostBottom |
978                     CF2_Locked      |
979                     CF2_Synthetic;
980        edge.scale = hintmap->scale;
981
982        cf2_hint_initZero( &invalid );
983        cf2_hintmap_insertHint( hintmap, &edge, &invalid );
984      }
985    }
986    else
987    {
988      /* insert remaining hints */
989
990      maskPtr = cf2_hintmask_getMaskPtr( &tempHintMask );
991
992      for ( i = 0, maskByte = 0x80; i < bitCount; i++ )
993      {
994        if ( maskByte & *maskPtr )
995        {
996          CF2_HintRec  bottomHintEdge, topHintEdge;
997
998
999          cf2_hint_init( &bottomHintEdge,
1000                         hStemHintArray,
1001                         i,
1002                         font,
1003                         hintOrigin,
1004                         hintmap->scale,
1005                         TRUE /* bottom */ );
1006          cf2_hint_init( &topHintEdge,
1007                         hStemHintArray,
1008                         i,
1009                         font,
1010                         hintOrigin,
1011                         hintmap->scale,
1012                         FALSE /* top */ );
1013
1014          cf2_hintmap_insertHint( hintmap, &bottomHintEdge, &topHintEdge );
1015        }
1016
1017        if ( ( i & 7 ) == 7 )
1018        {
1019          /* move to next mask byte */
1020          maskPtr++;
1021          maskByte = 0x80;
1022        }
1023        else
1024          maskByte >>= 1;
1025      }
1026    }
1027
1028    FT_TRACE6(( initialMap ? "flags: [p]air [g]host [t]op "
1029                             "[b]ottom [L]ocked [S]ynthetic\n"
1030                             "Initial hintmap\n"
1031                           : "Hints:\n" ));
1032    cf2_hintmap_dump( hintmap );
1033
1034    /*
1035     * Note: The following line is a convenient place to break when
1036     *       debugging hinting.  Examine `hintmap->edge' for the list of
1037     *       enabled hints, then step over the call to see the effect of
1038     *       adjustment.  We stop here first on the recursive call that
1039     *       creates the initial map, and then on each counter group and
1040     *       hint zone.
1041     */
1042
1043    /* adjust positions of hint edges that are not locked to blue zones */
1044    cf2_hintmap_adjustHints( hintmap );
1045
1046    FT_TRACE6(( "(adjusted)\n" ));
1047    cf2_hintmap_dump( hintmap );
1048
1049    /* save the position of all hints that were used in this hint map; */
1050    /* if we use them again, we'll locate them in the same position    */
1051    if ( !initialMap )
1052    {
1053      for ( i = 0; i < hintmap->count; i++ )
1054      {
1055        if ( !cf2_hint_isSynthetic( &hintmap->edge[i] ) )
1056        {
1057          /* Note: include both valid and invalid edges            */
1058          /* Note: top and bottom edges are copied back separately */
1059          CF2_StemHint  stemhint = (CF2_StemHint)
1060                          cf2_arrstack_getPointer( hStemHintArray,
1061                                                   hintmap->edge[i].index );
1062
1063
1064          if ( cf2_hint_isTop( &hintmap->edge[i] ) )
1065            stemhint->maxDS = hintmap->edge[i].dsCoord;
1066          else
1067            stemhint->minDS = hintmap->edge[i].dsCoord;
1068
1069          stemhint->used = TRUE;
1070        }
1071      }
1072    }
1073
1074    /* hint map is ready to use */
1075    hintmap->isValid = TRUE;
1076
1077    /* remember this mask has been used */
1078    cf2_hintmask_setNew( hintMask, FALSE );
1079  }
1080
1081
1082  FT_LOCAL_DEF( void )
1083  cf2_glyphpath_init( CF2_GlyphPath         glyphpath,
1084                      CF2_Font              font,
1085                      CF2_OutlineCallbacks  callbacks,
1086                      CF2_Fixed             scaleY,
1087                      /* CF2_Fixed  hShift, */
1088                      CF2_ArrStack          hStemHintArray,
1089                      CF2_ArrStack          vStemHintArray,
1090                      CF2_HintMask          hintMask,
1091                      CF2_Fixed             hintOriginY,
1092                      const CF2_Blues       blues,
1093                      const FT_Vector*      fractionalTranslation )
1094  {
1095    FT_ZERO( glyphpath );
1096
1097    glyphpath->font      = font;
1098    glyphpath->callbacks = callbacks;
1099
1100    cf2_arrstack_init( &glyphpath->hintMoves,
1101                       font->memory,
1102                       &font->error,
1103                       sizeof ( CF2_HintMoveRec ) );
1104
1105    cf2_hintmap_init( &glyphpath->initialHintMap,
1106                      font,
1107                      &glyphpath->initialHintMap,
1108                      &glyphpath->hintMoves,
1109                      scaleY );
1110    cf2_hintmap_init( &glyphpath->firstHintMap,
1111                      font,
1112                      &glyphpath->initialHintMap,
1113                      &glyphpath->hintMoves,
1114                      scaleY );
1115    cf2_hintmap_init( &glyphpath->hintMap,
1116                      font,
1117                      &glyphpath->initialHintMap,
1118                      &glyphpath->hintMoves,
1119                      scaleY );
1120
1121    glyphpath->scaleX = font->innerTransform.a;
1122    glyphpath->scaleC = font->innerTransform.c;
1123    glyphpath->scaleY = font->innerTransform.d;
1124
1125    glyphpath->fractionalTranslation = *fractionalTranslation;
1126
1127#if 0
1128    glyphpath->hShift = hShift;       /* for fauxing */
1129#endif
1130
1131    glyphpath->hStemHintArray = hStemHintArray;
1132    glyphpath->vStemHintArray = vStemHintArray;
1133    glyphpath->hintMask       = hintMask;      /* ptr to current mask */
1134    glyphpath->hintOriginY    = hintOriginY;
1135    glyphpath->blues          = blues;
1136    glyphpath->darken         = font->darkened; /* TODO: should we make copies? */
1137    glyphpath->xOffset        = font->darkenX;
1138    glyphpath->yOffset        = font->darkenY;
1139    glyphpath->miterLimit     = 2 * FT_MAX(
1140                                     cf2_fixedAbs( glyphpath->xOffset ),
1141                                     cf2_fixedAbs( glyphpath->yOffset ) );
1142
1143    /* .1 character space unit */
1144    glyphpath->snapThreshold = cf2_doubleToFixed( 0.1 );
1145
1146    glyphpath->moveIsPending = TRUE;
1147    glyphpath->pathIsOpen    = FALSE;
1148    glyphpath->pathIsClosing = FALSE;
1149    glyphpath->elemIsQueued  = FALSE;
1150  }
1151
1152
1153  FT_LOCAL_DEF( void )
1154  cf2_glyphpath_finalize( CF2_GlyphPath  glyphpath )
1155  {
1156    cf2_arrstack_finalize( &glyphpath->hintMoves );
1157  }
1158
1159
1160  /*
1161   * Hint point in y-direction and apply outerTransform.
1162   * Input `current' hint map (which is actually delayed by one element).
1163   * Input x,y point in Character Space.
1164   * Output x,y point in Device Space, including translation.
1165   */
1166  static void
1167  cf2_glyphpath_hintPoint( CF2_GlyphPath  glyphpath,
1168                           CF2_HintMap    hintmap,
1169                           FT_Vector*     ppt,
1170                           CF2_Fixed      x,
1171                           CF2_Fixed      y )
1172  {
1173    FT_Vector  pt;   /* hinted point in upright DS */
1174
1175
1176    pt.x = ADD_INT32( FT_MulFix( glyphpath->scaleX, x ),
1177                      FT_MulFix( glyphpath->scaleC, y ) );
1178    pt.y = cf2_hintmap_map( hintmap, y );
1179
1180    ppt->x = ADD_INT32(
1181               FT_MulFix( glyphpath->font->outerTransform.a, pt.x ),
1182               ADD_INT32(
1183                 FT_MulFix( glyphpath->font->outerTransform.c, pt.y ),
1184                 glyphpath->fractionalTranslation.x ) );
1185    ppt->y = ADD_INT32(
1186               FT_MulFix( glyphpath->font->outerTransform.b, pt.x ),
1187               ADD_INT32(
1188                 FT_MulFix( glyphpath->font->outerTransform.d, pt.y ),
1189                 glyphpath->fractionalTranslation.y ) );
1190  }
1191
1192
1193  /*
1194   * From two line segments, (u1,u2) and (v1,v2), compute a point of
1195   * intersection on the corresponding lines.
1196   * Return false if no intersection is found, or if the intersection is
1197   * too far away from the ends of the line segments, u2 and v1.
1198   *
1199   */
1200  static FT_Bool
1201  cf2_glyphpath_computeIntersection( CF2_GlyphPath     glyphpath,
1202                                     const FT_Vector*  u1,
1203                                     const FT_Vector*  u2,
1204                                     const FT_Vector*  v1,
1205                                     const FT_Vector*  v2,
1206                                     FT_Vector*        intersection )
1207  {
1208    /*
1209     * Let `u' be a zero-based vector from the first segment, `v' from the
1210     * second segment.
1211     * Let `w 'be the zero-based vector from `u1' to `v1'.
1212     * `perp' is the `perpendicular dot product'; see
1213     * https://mathworld.wolfram.com/PerpDotProduct.html.
1214     * `s' is the parameter for the parametric line for the first segment
1215     * (`u').
1216     *
1217     * See notation in
1218     * http://softsurfer.com/Archive/algorithm_0104/algorithm_0104B.htm.
1219     * Calculations are done in 16.16, but must handle the squaring of
1220     * line lengths in character space.  We scale all vectors by 1/32 to
1221     * avoid overflow.  This allows values up to 4095 to be squared.  The
1222     * scale factor cancels in the divide.
1223     *
1224     * TODO: the scale factor could be computed from UnitsPerEm.
1225     *
1226     */
1227
1228#define cf2_perp( a, b )                                    \
1229          ( FT_MulFix( a.x, b.y ) - FT_MulFix( a.y, b.x ) )
1230
1231  /* round and divide by 32 */
1232#define CF2_CS_SCALE( x )         \
1233          ( ( (x) + 0x10 ) >> 5 )
1234
1235    FT_Vector  u, v, w;      /* scaled vectors */
1236    CF2_Fixed  denominator, s;
1237
1238
1239    u.x = CF2_CS_SCALE( SUB_INT32( u2->x, u1->x ) );
1240    u.y = CF2_CS_SCALE( SUB_INT32( u2->y, u1->y ) );
1241    v.x = CF2_CS_SCALE( SUB_INT32( v2->x, v1->x ) );
1242    v.y = CF2_CS_SCALE( SUB_INT32( v2->y, v1->y ) );
1243    w.x = CF2_CS_SCALE( SUB_INT32( v1->x, u1->x ) );
1244    w.y = CF2_CS_SCALE( SUB_INT32( v1->y, u1->y ) );
1245
1246    denominator = cf2_perp( u, v );
1247
1248    if ( denominator == 0 )
1249      return FALSE;           /* parallel or coincident lines */
1250
1251    s = FT_DivFix( cf2_perp( w, v ), denominator );
1252
1253    intersection->x = ADD_INT32( u1->x,
1254                                 FT_MulFix( s, SUB_INT32( u2->x, u1->x ) ) );
1255    intersection->y = ADD_INT32( u1->y,
1256                                 FT_MulFix( s, SUB_INT32( u2->y, u1->y ) ) );
1257
1258
1259    /*
1260     * Special case snapping for horizontal and vertical lines.
1261     * This cleans up intersections and reduces problems with winding
1262     * order detection.
1263     * Sample case is sbc cd KozGoPr6N-Medium.otf 20 16685.
1264     * Note: these calculations are in character space.
1265     *
1266     */
1267
1268    if ( u1->x == u2->x                                                &&
1269         cf2_fixedAbs( SUB_INT32( intersection->x,
1270                                  u1->x ) ) < glyphpath->snapThreshold )
1271      intersection->x = u1->x;
1272    if ( u1->y == u2->y                                                &&
1273         cf2_fixedAbs( SUB_INT32( intersection->y,
1274                                  u1->y ) ) < glyphpath->snapThreshold )
1275      intersection->y = u1->y;
1276
1277    if ( v1->x == v2->x                                                &&
1278         cf2_fixedAbs( SUB_INT32( intersection->x,
1279                                  v1->x ) ) < glyphpath->snapThreshold )
1280      intersection->x = v1->x;
1281    if ( v1->y == v2->y                                                &&
1282         cf2_fixedAbs( SUB_INT32( intersection->y,
1283                                  v1->y ) ) < glyphpath->snapThreshold )
1284      intersection->y = v1->y;
1285
1286    /* limit the intersection distance from midpoint of u2 and v1 */
1287    if ( cf2_fixedAbs( intersection->x - ADD_INT32( u2->x, v1->x ) / 2 ) >
1288           glyphpath->miterLimit                                           ||
1289         cf2_fixedAbs( intersection->y - ADD_INT32( u2->y, v1->y ) / 2 ) >
1290           glyphpath->miterLimit                                           )
1291      return FALSE;
1292
1293    return TRUE;
1294  }
1295
1296
1297  /*
1298   * Push the cached element (glyphpath->prevElem*) to the outline
1299   * consumer.  When a darkening offset is used, the end point of the
1300   * cached element may be adjusted to an intersection point or we may
1301   * synthesize a connecting line to the current element.  If we are
1302   * closing a subpath, we may also generate a connecting line to the start
1303   * point.
1304   *
1305   * This is where Character Space (CS) is converted to Device Space (DS)
1306   * using a hint map.  This calculation must use a HintMap that was valid
1307   * at the time the element was saved.  For the first point in a subpath,
1308   * that is a saved HintMap.  For most elements, it just means the caller
1309   * has delayed building a HintMap from the current HintMask.
1310   *
1311   * Transform each point with outerTransform and call the outline
1312   * callbacks.  This is a general 3x3 transform:
1313   *
1314   *   x' = a*x + c*y + tx, y' = b*x + d*y + ty
1315   *
1316   * but it uses 4 elements from CF2_Font and the translation part
1317   * from CF2_GlyphPath.
1318   *
1319   */
1320  static void
1321  cf2_glyphpath_pushPrevElem( CF2_GlyphPath  glyphpath,
1322                              CF2_HintMap    hintmap,
1323                              FT_Vector*     nextP0,
1324                              FT_Vector      nextP1,
1325                              FT_Bool        close )
1326  {
1327    CF2_CallbackParamsRec  params;
1328
1329    FT_Vector*  prevP0;
1330    FT_Vector*  prevP1;
1331
1332    FT_Vector  intersection    = { 0, 0 };
1333    FT_Bool    useIntersection = FALSE;
1334
1335
1336    FT_ASSERT( glyphpath->prevElemOp == CF2_PathOpLineTo ||
1337               glyphpath->prevElemOp == CF2_PathOpCubeTo );
1338
1339    if ( glyphpath->prevElemOp == CF2_PathOpLineTo )
1340    {
1341      prevP0 = &glyphpath->prevElemP0;
1342      prevP1 = &glyphpath->prevElemP1;
1343    }
1344    else
1345    {
1346      prevP0 = &glyphpath->prevElemP2;
1347      prevP1 = &glyphpath->prevElemP3;
1348    }
1349
1350    /* optimization: if previous and next elements are offset by the same */
1351    /* amount, then there will be no gap, and no need to compute an       */
1352    /* intersection.                                                      */
1353    if ( prevP1->x != nextP0->x || prevP1->y != nextP0->y )
1354    {
1355      /* previous element does not join next element:             */
1356      /* adjust end point of previous element to the intersection */
1357      useIntersection = cf2_glyphpath_computeIntersection( glyphpath,
1358                                                           prevP0,
1359                                                           prevP1,
1360                                                           nextP0,
1361                                                           &nextP1,
1362                                                           &intersection );
1363      if ( useIntersection )
1364      {
1365        /* modify the last point of the cached element (either line or */
1366        /* curve)                                                      */
1367        *prevP1 = intersection;
1368      }
1369    }
1370
1371    params.pt0 = glyphpath->currentDS;
1372
1373    switch( glyphpath->prevElemOp )
1374    {
1375    case CF2_PathOpLineTo:
1376      params.op = CF2_PathOpLineTo;
1377
1378      /* note: pt2 and pt3 are unused */
1379
1380      if ( close )
1381      {
1382        /* use first hint map if closing */
1383        cf2_glyphpath_hintPoint( glyphpath,
1384                                 &glyphpath->firstHintMap,
1385                                 &params.pt1,
1386                                 glyphpath->prevElemP1.x,
1387                                 glyphpath->prevElemP1.y );
1388      }
1389      else
1390      {
1391        cf2_glyphpath_hintPoint( glyphpath,
1392                                 hintmap,
1393                                 &params.pt1,
1394                                 glyphpath->prevElemP1.x,
1395                                 glyphpath->prevElemP1.y );
1396      }
1397
1398      /* output only non-zero length lines */
1399      if ( params.pt0.x != params.pt1.x || params.pt0.y != params.pt1.y )
1400      {
1401        glyphpath->callbacks->lineTo( glyphpath->callbacks, &params );
1402
1403        glyphpath->currentDS = params.pt1;
1404      }
1405      break;
1406
1407    case CF2_PathOpCubeTo:
1408      params.op = CF2_PathOpCubeTo;
1409
1410      /* TODO: should we intersect the interior joins (p1-p2 and p2-p3)? */
1411      cf2_glyphpath_hintPoint( glyphpath,
1412                               hintmap,
1413                               &params.pt1,
1414                               glyphpath->prevElemP1.x,
1415                               glyphpath->prevElemP1.y );
1416      cf2_glyphpath_hintPoint( glyphpath,
1417                               hintmap,
1418                               &params.pt2,
1419                               glyphpath->prevElemP2.x,
1420                               glyphpath->prevElemP2.y );
1421      cf2_glyphpath_hintPoint( glyphpath,
1422                               hintmap,
1423                               &params.pt3,
1424                               glyphpath->prevElemP3.x,
1425                               glyphpath->prevElemP3.y );
1426
1427      glyphpath->callbacks->cubeTo( glyphpath->callbacks, &params );
1428
1429      glyphpath->currentDS = params.pt3;
1430
1431      break;
1432    }
1433
1434    if ( !useIntersection || close )
1435    {
1436      /* insert connecting line between end of previous element and start */
1437      /* of current one                                                   */
1438      /* note: at the end of a subpath, we might do both, so use `nextP0' */
1439      /* before we change it, below                                       */
1440
1441      if ( close )
1442      {
1443        /* if we are closing the subpath, then nextP0 is in the first     */
1444        /* hint zone                                                      */
1445        cf2_glyphpath_hintPoint( glyphpath,
1446                                 &glyphpath->firstHintMap,
1447                                 &params.pt1,
1448                                 nextP0->x,
1449                                 nextP0->y );
1450      }
1451      else
1452      {
1453        cf2_glyphpath_hintPoint( glyphpath,
1454                                 hintmap,
1455                                 &params.pt1,
1456                                 nextP0->x,
1457                                 nextP0->y );
1458      }
1459
1460      if ( params.pt1.x != glyphpath->currentDS.x ||
1461           params.pt1.y != glyphpath->currentDS.y )
1462      {
1463        /* length is nonzero */
1464        params.op  = CF2_PathOpLineTo;
1465        params.pt0 = glyphpath->currentDS;
1466
1467        /* note: pt2 and pt3 are unused */
1468        glyphpath->callbacks->lineTo( glyphpath->callbacks, &params );
1469
1470        glyphpath->currentDS = params.pt1;
1471      }
1472    }
1473
1474    if ( useIntersection )
1475    {
1476      /* return intersection point to caller */
1477      *nextP0 = intersection;
1478    }
1479  }
1480
1481
1482  /* push a MoveTo element based on current point and offset of current */
1483  /* element                                                            */
1484  static void
1485  cf2_glyphpath_pushMove( CF2_GlyphPath  glyphpath,
1486                          FT_Vector      start )
1487  {
1488    CF2_CallbackParamsRec  params;
1489
1490
1491    params.op  = CF2_PathOpMoveTo;
1492    params.pt0 = glyphpath->currentDS;
1493
1494    /* Test if move has really happened yet; it would have called */
1495    /* `cf2_hintmap_build' to set `isValid'.                   */
1496    if ( !cf2_hintmap_isValid( &glyphpath->hintMap ) )
1497    {
1498      /* we are here iff first subpath is missing a moveto operator: */
1499      /* synthesize first moveTo to finish initialization of hintMap */
1500      cf2_glyphpath_moveTo( glyphpath,
1501                            glyphpath->start.x,
1502                            glyphpath->start.y );
1503    }
1504
1505    cf2_glyphpath_hintPoint( glyphpath,
1506                             &glyphpath->hintMap,
1507                             &params.pt1,
1508                             start.x,
1509                             start.y );
1510
1511    /* note: pt2 and pt3 are unused */
1512    glyphpath->callbacks->moveTo( glyphpath->callbacks, &params );
1513
1514    glyphpath->currentDS    = params.pt1;
1515    glyphpath->offsetStart0 = start;
1516  }
1517
1518
1519  /*
1520   * All coordinates are in character space.
1521   * On input, (x1, y1) and (x2, y2) give line segment.
1522   * On output, (x, y) give offset vector.
1523   * We use a piecewise approximation to trig functions.
1524   *
1525   * TODO: Offset true perpendicular and proper length
1526   *       supply the y-translation for hinting here, too,
1527   *       that adds yOffset unconditionally to *y.
1528   */
1529  static void
1530  cf2_glyphpath_computeOffset( CF2_GlyphPath  glyphpath,
1531                               CF2_Fixed      x1,
1532                               CF2_Fixed      y1,
1533                               CF2_Fixed      x2,
1534                               CF2_Fixed      y2,
1535                               CF2_Fixed*     x,
1536                               CF2_Fixed*     y )
1537  {
1538    CF2_Fixed  dx = SUB_INT32( x2, x1 );
1539    CF2_Fixed  dy = SUB_INT32( y2, y1 );
1540
1541
1542    /* note: negative offsets don't work here; negate deltas to change */
1543    /* quadrants, below                                                */
1544    if ( glyphpath->font->reverseWinding )
1545    {
1546      dx = NEG_INT32( dx );
1547      dy = NEG_INT32( dy );
1548    }
1549
1550    *x = *y = 0;
1551
1552    if ( !glyphpath->darken )
1553        return;
1554
1555    /* add momentum for this path element */
1556    glyphpath->callbacks->windingMomentum =
1557      ADD_INT32( glyphpath->callbacks->windingMomentum,
1558                 cf2_getWindingMomentum( x1, y1, x2, y2 ) );
1559
1560    /* note: allow mixed integer and fixed multiplication here */
1561    if ( dx >= 0 )
1562    {
1563      if ( dy >= 0 )
1564      {
1565        /* first quadrant, +x +y */
1566
1567        if ( dx > MUL_INT32( 2, dy ) )
1568        {
1569          /* +x */
1570          *x = 0;
1571          *y = 0;
1572        }
1573        else if ( dy > MUL_INT32( 2, dx ) )
1574        {
1575          /* +y */
1576          *x = glyphpath->xOffset;
1577          *y = glyphpath->yOffset;
1578        }
1579        else
1580        {
1581          /* +x +y */
1582          *x = FT_MulFix( cf2_doubleToFixed( 0.7 ),
1583                          glyphpath->xOffset );
1584          *y = FT_MulFix( cf2_doubleToFixed( 1.0 - 0.7 ),
1585                          glyphpath->yOffset );
1586        }
1587      }
1588      else
1589      {
1590        /* fourth quadrant, +x -y */
1591
1592        if ( dx > MUL_INT32( -2, dy ) )
1593        {
1594          /* +x */
1595          *x = 0;
1596          *y = 0;
1597        }
1598        else if ( NEG_INT32( dy ) > MUL_INT32( 2, dx ) )
1599        {
1600          /* -y */
1601          *x = NEG_INT32( glyphpath->xOffset );
1602          *y = glyphpath->yOffset;
1603        }
1604        else
1605        {
1606          /* +x -y */
1607          *x = FT_MulFix( cf2_doubleToFixed( -0.7 ),
1608                          glyphpath->xOffset );
1609          *y = FT_MulFix( cf2_doubleToFixed( 1.0 - 0.7 ),
1610                          glyphpath->yOffset );
1611        }
1612      }
1613    }
1614    else
1615    {
1616      if ( dy >= 0 )
1617      {
1618        /* second quadrant, -x +y */
1619
1620        if ( NEG_INT32( dx ) > MUL_INT32( 2, dy ) )
1621        {
1622          /* -x */
1623          *x = 0;
1624          *y = MUL_INT32( 2, glyphpath->yOffset );
1625        }
1626        else if ( dy > MUL_INT32( -2, dx ) )
1627        {
1628          /* +y */
1629          *x = glyphpath->xOffset;
1630          *y = glyphpath->yOffset;
1631        }
1632        else
1633        {
1634          /* -x +y */
1635          *x = FT_MulFix( cf2_doubleToFixed( 0.7 ),
1636                          glyphpath->xOffset );
1637          *y = FT_MulFix( cf2_doubleToFixed( 1.0 + 0.7 ),
1638                          glyphpath->yOffset );
1639        }
1640      }
1641      else
1642      {
1643        /* third quadrant, -x -y */
1644
1645        if ( NEG_INT32( dx ) > MUL_INT32( -2, dy ) )
1646        {
1647          /* -x */
1648          *x = 0;
1649          *y = MUL_INT32( 2, glyphpath->yOffset );
1650        }
1651        else if ( NEG_INT32( dy ) > MUL_INT32( -2, dx ) )
1652        {
1653          /* -y */
1654          *x = NEG_INT32( glyphpath->xOffset );
1655          *y = glyphpath->yOffset;
1656        }
1657        else
1658        {
1659          /* -x -y */
1660          *x = FT_MulFix( cf2_doubleToFixed( -0.7 ),
1661                          glyphpath->xOffset );
1662          *y = FT_MulFix( cf2_doubleToFixed( 1.0 + 0.7 ),
1663                          glyphpath->yOffset );
1664        }
1665      }
1666    }
1667  }
1668
1669
1670  /*
1671   * The functions cf2_glyphpath_{moveTo,lineTo,curveTo,closeOpenPath} are
1672   * called by the interpreter with Character Space (CS) coordinates.  Each
1673   * path element is placed into a queue of length one to await the
1674   * calculation of the following element.  At that time, the darkening
1675   * offset of the following element is known and joins can be computed,
1676   * including possible modification of this element, before mapping to
1677   * Device Space (DS) and passing it on to the outline consumer.
1678   *
1679   */
1680  FT_LOCAL_DEF( void )
1681  cf2_glyphpath_moveTo( CF2_GlyphPath  glyphpath,
1682                        CF2_Fixed      x,
1683                        CF2_Fixed      y )
1684  {
1685    cf2_glyphpath_closeOpenPath( glyphpath );
1686
1687    /* save the parameters of the move for later, when we'll know how to */
1688    /* offset it;                                                        */
1689    /* also save last move point */
1690    glyphpath->currentCS.x = glyphpath->start.x = x;
1691    glyphpath->currentCS.y = glyphpath->start.y = y;
1692
1693    glyphpath->moveIsPending = TRUE;
1694
1695    /* ensure we have a valid map with current mask */
1696    if ( !cf2_hintmap_isValid( &glyphpath->hintMap ) ||
1697         cf2_hintmask_isNew( glyphpath->hintMask )   )
1698      cf2_hintmap_build( &glyphpath->hintMap,
1699                         glyphpath->hStemHintArray,
1700                         glyphpath->vStemHintArray,
1701                         glyphpath->hintMask,
1702                         glyphpath->hintOriginY,
1703                         FALSE );
1704
1705    /* save a copy of current HintMap to use when drawing initial point */
1706    glyphpath->firstHintMap = glyphpath->hintMap;     /* structure copy */
1707  }
1708
1709
1710  FT_LOCAL_DEF( void )
1711  cf2_glyphpath_lineTo( CF2_GlyphPath  glyphpath,
1712                        CF2_Fixed      x,
1713                        CF2_Fixed      y )
1714  {
1715    CF2_Fixed  xOffset, yOffset;
1716    FT_Vector  P0, P1;
1717    FT_Bool    newHintMap;
1718
1719    /*
1720     * New hints will be applied after cf2_glyphpath_pushPrevElem has run.
1721     * In case this is a synthesized closing line, any new hints should be
1722     * delayed until this path is closed (`cf2_hintmask_isNew' will be
1723     * called again before the next line or curve).
1724     */
1725
1726    /* true if new hint map not on close */
1727    newHintMap = cf2_hintmask_isNew( glyphpath->hintMask ) &&
1728                 !glyphpath->pathIsClosing;
1729
1730    /*
1731     * Zero-length lines may occur in the charstring.  Because we cannot
1732     * compute darkening offsets or intersections from zero-length lines,
1733     * it is best to remove them and avoid artifacts.  However, zero-length
1734     * lines in CS at the start of a new hint map can generate non-zero
1735     * lines in DS due to hint substitution.  We detect a change in hint
1736     * map here and pass those zero-length lines along.
1737     */
1738
1739    /*
1740     * Note: Find explicitly closed paths here with a conditional
1741     *       breakpoint using
1742     *
1743     *         !gp->pathIsClosing && gp->start.x == x && gp->start.y == y
1744     *
1745     */
1746
1747    if ( glyphpath->currentCS.x == x &&
1748         glyphpath->currentCS.y == y &&
1749         !newHintMap                 )
1750      /*
1751       * Ignore zero-length lines in CS where the hint map is the same
1752       * because the line in DS will also be zero length.
1753       *
1754       * Ignore zero-length lines when we synthesize a closing line because
1755       * the close will be handled in cf2_glyphPath_pushPrevElem.
1756       */
1757      return;
1758
1759    cf2_glyphpath_computeOffset( glyphpath,
1760                                 glyphpath->currentCS.x,
1761                                 glyphpath->currentCS.y,
1762                                 x,
1763                                 y,
1764                                 &xOffset,
1765                                 &yOffset );
1766
1767    /* construct offset points */
1768    P0.x = ADD_INT32( glyphpath->currentCS.x, xOffset );
1769    P0.y = ADD_INT32( glyphpath->currentCS.y, yOffset );
1770    P1.x = ADD_INT32( x, xOffset );
1771    P1.y = ADD_INT32( y, yOffset );
1772
1773    if ( glyphpath->moveIsPending )
1774    {
1775      /* emit offset 1st point as MoveTo */
1776      cf2_glyphpath_pushMove( glyphpath, P0 );
1777
1778      glyphpath->moveIsPending = FALSE;  /* adjust state machine */
1779      glyphpath->pathIsOpen    = TRUE;
1780
1781      glyphpath->offsetStart1 = P1;              /* record second point */
1782    }
1783
1784    if ( glyphpath->elemIsQueued )
1785    {
1786      FT_ASSERT( cf2_hintmap_isValid( &glyphpath->hintMap ) ||
1787                 glyphpath->hintMap.count == 0              );
1788
1789      cf2_glyphpath_pushPrevElem( glyphpath,
1790                                  &glyphpath->hintMap,
1791                                  &P0,
1792                                  P1,
1793                                  FALSE );
1794    }
1795
1796    /* queue the current element with offset points */
1797    glyphpath->elemIsQueued = TRUE;
1798    glyphpath->prevElemOp   = CF2_PathOpLineTo;
1799    glyphpath->prevElemP0   = P0;
1800    glyphpath->prevElemP1   = P1;
1801
1802    /* update current map */
1803    if ( newHintMap )
1804      cf2_hintmap_build( &glyphpath->hintMap,
1805                         glyphpath->hStemHintArray,
1806                         glyphpath->vStemHintArray,
1807                         glyphpath->hintMask,
1808                         glyphpath->hintOriginY,
1809                         FALSE );
1810
1811    glyphpath->currentCS.x = x;     /* pre-offset current point */
1812    glyphpath->currentCS.y = y;
1813  }
1814
1815
1816  FT_LOCAL_DEF( void )
1817  cf2_glyphpath_curveTo( CF2_GlyphPath  glyphpath,
1818                         CF2_Fixed      x1,
1819                         CF2_Fixed      y1,
1820                         CF2_Fixed      x2,
1821                         CF2_Fixed      y2,
1822                         CF2_Fixed      x3,
1823                         CF2_Fixed      y3 )
1824  {
1825    CF2_Fixed  xOffset1, yOffset1, xOffset3, yOffset3;
1826    FT_Vector  P0, P1, P2, P3;
1827
1828
1829    /* TODO: ignore zero length portions of curve?? */
1830    cf2_glyphpath_computeOffset( glyphpath,
1831                                 glyphpath->currentCS.x,
1832                                 glyphpath->currentCS.y,
1833                                 x1,
1834                                 y1,
1835                                 &xOffset1,
1836                                 &yOffset1 );
1837    cf2_glyphpath_computeOffset( glyphpath,
1838                                 x2,
1839                                 y2,
1840                                 x3,
1841                                 y3,
1842                                 &xOffset3,
1843                                 &yOffset3 );
1844
1845    /* add momentum from the middle segment */
1846    glyphpath->callbacks->windingMomentum =
1847      ADD_INT32( glyphpath->callbacks->windingMomentum,
1848                 cf2_getWindingMomentum( x1, y1, x2, y2 ) );
1849
1850    /* construct offset points */
1851    P0.x = ADD_INT32( glyphpath->currentCS.x, xOffset1 );
1852    P0.y = ADD_INT32( glyphpath->currentCS.y, yOffset1 );
1853    P1.x = ADD_INT32( x1, xOffset1 );
1854    P1.y = ADD_INT32( y1, yOffset1 );
1855    /* note: preserve angle of final segment by using offset3 at both ends */
1856    P2.x = ADD_INT32( x2, xOffset3 );
1857    P2.y = ADD_INT32( y2, yOffset3 );
1858    P3.x = ADD_INT32( x3, xOffset3 );
1859    P3.y = ADD_INT32( y3, yOffset3 );
1860
1861    if ( glyphpath->moveIsPending )
1862    {
1863      /* emit offset 1st point as MoveTo */
1864      cf2_glyphpath_pushMove( glyphpath, P0 );
1865
1866      glyphpath->moveIsPending = FALSE;
1867      glyphpath->pathIsOpen    = TRUE;
1868
1869      glyphpath->offsetStart1 = P1;              /* record second point */
1870    }
1871
1872    if ( glyphpath->elemIsQueued )
1873    {
1874      FT_ASSERT( cf2_hintmap_isValid( &glyphpath->hintMap ) ||
1875                 glyphpath->hintMap.count == 0              );
1876
1877      cf2_glyphpath_pushPrevElem( glyphpath,
1878                                  &glyphpath->hintMap,
1879                                  &P0,
1880                                  P1,
1881                                  FALSE );
1882    }
1883
1884    /* queue the current element with offset points */
1885    glyphpath->elemIsQueued = TRUE;
1886    glyphpath->prevElemOp   = CF2_PathOpCubeTo;
1887    glyphpath->prevElemP0   = P0;
1888    glyphpath->prevElemP1   = P1;
1889    glyphpath->prevElemP2   = P2;
1890    glyphpath->prevElemP3   = P3;
1891
1892    /* update current map */
1893    if ( cf2_hintmask_isNew( glyphpath->hintMask ) )
1894      cf2_hintmap_build( &glyphpath->hintMap,
1895                         glyphpath->hStemHintArray,
1896                         glyphpath->vStemHintArray,
1897                         glyphpath->hintMask,
1898                         glyphpath->hintOriginY,
1899                         FALSE );
1900
1901    glyphpath->currentCS.x = x3;       /* pre-offset current point */
1902    glyphpath->currentCS.y = y3;
1903  }
1904
1905
1906  FT_LOCAL_DEF( void )
1907  cf2_glyphpath_closeOpenPath( CF2_GlyphPath  glyphpath )
1908  {
1909    if ( glyphpath->pathIsOpen )
1910    {
1911      /*
1912       * A closing line in Character Space line is always generated below
1913       * with `cf2_glyphPath_lineTo'.  It may be ignored later if it turns
1914       * out to be zero length in Device Space.
1915       */
1916      glyphpath->pathIsClosing = TRUE;
1917
1918      cf2_glyphpath_lineTo( glyphpath,
1919                            glyphpath->start.x,
1920                            glyphpath->start.y );
1921
1922      /* empty the final element from the queue and close the path */
1923      if ( glyphpath->elemIsQueued )
1924        cf2_glyphpath_pushPrevElem( glyphpath,
1925                                    &glyphpath->hintMap,
1926                                    &glyphpath->offsetStart0,
1927                                    glyphpath->offsetStart1,
1928                                    TRUE );
1929
1930      /* reset state machine */
1931      glyphpath->moveIsPending = TRUE;
1932      glyphpath->pathIsOpen    = FALSE;
1933      glyphpath->pathIsClosing = FALSE;
1934      glyphpath->elemIsQueued  = FALSE;
1935    }
1936  }
1937
1938
1939/* END */
1940