4 * Copyright (C) 2011 by Werner Lemberg.
6 * This file is part of the ttfautohint library, and may only be used,
7 * modified, and distributed under the terms given in `COPYING'. By
8 * continuing to use, modify, or distribute this file you indicate that you
9 * have read `COPYING' and understand and accept it fully.
11 * The file `COPYING' mentioned in the previous paragraph is distributed
12 * with the ttfautohint library.
16 /* originally file `aflatin.c' (2011-Mar-28) from FreeType */
18 /* heavily modified 2011 by Werner Lemberg <wl@gnu.org> */
23 #include FT_ADVANCES_H
29 #ifdef TA_CONFIG_OPTION_USE_WARPER
34 /* find segments and links, compute all stem widths, and initialize */
35 /* standard width and height for the glyph with given charcode */
38 ta_latin_metrics_init_widths(TA_LatinMetrics metrics
,
42 /* scan the array of segments in each direction */
43 TA_GlyphHintsRec hints
[1];
46 ta_glyph_hints_init(hints
);
48 metrics
->axis
[TA_DIMENSION_HORZ
].width_count
= 0;
49 metrics
->axis
[TA_DIMENSION_VERT
].width_count
= 0;
55 TA_LatinMetricsRec dummy
[1];
56 TA_Scaler scaler
= &dummy
->root
.scaler
;
59 glyph_index
= FT_Get_Char_Index(face
, charcode
);
63 error
= FT_Load_Glyph(face
, glyph_index
, FT_LOAD_NO_SCALE
);
64 if (error
|| face
->glyph
->outline
.n_points
<= 0)
67 memset(dummy
, 0, sizeof (TA_LatinMetricsRec
));
69 dummy
->units_per_em
= metrics
->units_per_em
;
71 scaler
->x_scale
= 0x10000L
;
72 scaler
->y_scale
= 0x10000L
;
77 scaler
->render_mode
= FT_RENDER_MODE_NORMAL
;
80 ta_glyph_hints_rescale(hints
, (TA_ScriptMetrics
)dummy
);
82 error
= ta_glyph_hints_reload(hints
, &face
->glyph
->outline
);
86 for (dim
= 0; dim
< TA_DIMENSION_MAX
; dim
++)
88 TA_LatinAxis axis
= &metrics
->axis
[dim
];
89 TA_AxisHints axhints
= &hints
->axis
[dim
];
91 TA_Segment seg
, limit
, link
;
92 FT_UInt num_widths
= 0;
95 error
= ta_latin_hints_compute_segments(hints
, (TA_Dimension
)dim
);
99 ta_latin_hints_link_segments(hints
, (TA_Dimension
)dim
);
101 seg
= axhints
->segments
;
102 limit
= seg
+ axhints
->num_segments
;
104 for (; seg
< limit
; seg
++)
108 /* we only consider stem segments there! */
116 dist
= seg
->pos
- link
->pos
;
120 if (num_widths
< TA_LATIN_MAX_WIDTHS
)
121 axis
->widths
[num_widths
++].org
= dist
;
125 ta_sort_widths(num_widths
, axis
->widths
);
126 axis
->width_count
= num_widths
;
130 for (dim
= 0; dim
< TA_DIMENSION_MAX
; dim
++)
132 TA_LatinAxis axis
= &metrics
->axis
[dim
];
136 stdw
= (axis
->width_count
> 0) ? axis
->widths
[0].org
137 : TA_LATIN_CONSTANT(metrics
, 50);
139 /* let's try 20% of the smallest width */
140 axis
->edge_distance_threshold
= stdw
/ 5;
141 axis
->standard_width
= stdw
;
142 axis
->extra_light
= 0;
146 ta_glyph_hints_done(hints
);
150 #define TA_LATIN_MAX_TEST_CHARACTERS 12
153 static const char ta_latin_blue_chars
[TA_LATIN_MAX_BLUES
]
154 [TA_LATIN_MAX_TEST_CHARACTERS
+ 1] =
165 /* find all blue zones; flat segments give the reference points, */
166 /* round segments the overshoot positions */
169 ta_latin_metrics_init_blues(TA_LatinMetrics metrics
,
172 FT_Pos flats
[TA_LATIN_MAX_TEST_CHARACTERS
];
173 FT_Pos rounds
[TA_LATIN_MAX_TEST_CHARACTERS
];
180 TA_LatinAxis axis
= &metrics
->axis
[TA_DIMENSION_VERT
];
181 FT_GlyphSlot glyph
= face
->glyph
;
184 /* we compute the blues simply by loading each character from the */
185 /* `ta_latin_blue_chars[blues]' string, then finding its top-most or */
186 /* bottom-most points (depending on `TA_IS_TOP_BLUE') */
188 TA_LOG(("blue zones computation\n"));
189 TA_LOG(("------------------------------------------------\n"));
191 for (bb
= 0; bb
< TA_LATIN_BLUE_MAX
; bb
++)
193 const char* p
= ta_latin_blue_chars
[bb
];
194 const char* limit
= p
+ TA_LATIN_MAX_TEST_CHARACTERS
;
199 TA_LOG(("blue %3d: ", bb
));
204 for (; p
< limit
&& *p
; p
++)
207 FT_Pos best_y
; /* same as points.y */
208 FT_Int best_point
, best_first
, best_last
;
213 TA_LOG(("'%c'", *p
));
215 /* load the character in the face -- skip unknown or empty ones */
216 glyph_index
= FT_Get_Char_Index(face
, (FT_UInt
)*p
);
217 if (glyph_index
== 0)
220 error
= FT_Load_Glyph(face
, glyph_index
, FT_LOAD_NO_SCALE
);
221 if (error
|| glyph
->outline
.n_points
<= 0)
224 /* now compute min or max point indices and coordinates */
225 points
= glyph
->outline
.points
;
227 best_y
= 0; /* make compiler happy */
228 best_first
= 0; /* ditto */
229 best_last
= 0; /* ditto */
237 for (nn
= 0; nn
< glyph
->outline
.n_contours
; first
= last
+ 1, nn
++)
239 FT_Int old_best_point
= best_point
;
243 last
= glyph
->outline
.contours
[nn
];
245 /* avoid single-point contours since they are never rasterized; */
246 /* in some fonts, they correspond to mark attachment points */
247 /* which are way outside of the glyph's real outline */
251 if (TA_LATIN_IS_TOP_BLUE(bb
))
253 for (pp
= first
; pp
<= last
; pp
++)
255 || points
[pp
].y
> best_y
)
258 best_y
= points
[pp
].y
;
263 for (pp
= first
; pp
<= last
; pp
++)
265 || points
[pp
].y
< best_y
)
268 best_y
= points
[pp
].y
;
272 if (best_point
!= old_best_point
)
278 TA_LOG(("%5ld", best_y
));
281 /* now check whether the point belongs to a straight or round */
282 /* segment; we first need to find in which contour the extremum */
283 /* lies, then inspect its previous and next points */
290 /* now look for the previous and next points that are not on the */
291 /* same Y coordinate and threshold the `closeness'... */
297 if (prev
> best_first
)
302 dist
= points
[prev
].y
- best_y
;
303 if (dist
< -5 || dist
> 5)
305 } while (prev
!= best_point
);
309 if (next
< best_last
)
314 dist
= points
[next
].y
- best_y
;
315 if (dist
< -5 || dist
> 5)
317 } while (next
!= best_point
);
319 /* now set the `round' flag depending on the segment's kind */
321 FT_CURVE_TAG(glyph
->outline
.tags
[prev
]) != FT_CURVE_TAG_ON
322 || FT_CURVE_TAG(glyph
->outline
.tags
[next
]) != FT_CURVE_TAG_ON
);
324 TA_LOG(("%c ", round
? 'r' : 'f'));
328 rounds
[num_rounds
++] = best_y
;
330 flats
[num_flats
++] = best_y
;
335 if (num_flats
== 0 && num_rounds
== 0)
337 /* we couldn't find a single glyph to compute this blue zone, */
338 /* we will simply ignore it then */
343 /* we have computed the contents of the `rounds' and `flats' tables, */
344 /* now determine the reference and overshoot position of the blue -- */
345 /* we simply take the median value after a simple sort */
346 ta_sort_pos(num_rounds
, rounds
);
347 ta_sort_pos(num_flats
, flats
);
349 blue
= &axis
->blues
[axis
->blue_count
];
350 blue_ref
= &blue
->ref
.org
;
351 blue_shoot
= &blue
->shoot
.org
;
358 *blue_shoot
= rounds
[num_rounds
/ 2];
360 else if (num_rounds
== 0)
363 *blue_shoot
= flats
[num_flats
/ 2];
367 *blue_ref
= flats
[num_flats
/ 2];
368 *blue_shoot
= rounds
[num_rounds
/ 2];
371 /* there are sometimes problems if the overshoot position of top */
372 /* zones is under its reference position, or the opposite for bottom */
373 /* zones; we must thus check everything there and correct the errors */
374 if (*blue_shoot
!= *blue_ref
)
376 FT_Pos ref
= *blue_ref
;
377 FT_Pos shoot
= *blue_shoot
;
378 FT_Bool over_ref
= FT_BOOL(shoot
> ref
);
381 if (TA_LATIN_IS_TOP_BLUE(bb
) ^ over_ref
)
383 *blue_shoot
= (shoot
+ ref
) / 2;
387 if (TA_LATIN_IS_TOP_BLUE(bb
))
388 blue
->flags
|= TA_LATIN_BLUE_TOP
;
390 /* the following flag is used later to adjust the y and x scales */
391 /* in order to optimize the pixel grid alignment */
392 /* of the top of small letters */
393 if (bb
== TA_LATIN_BLUE_SMALL_TOP
)
394 blue
->flags
|= TA_LATIN_BLUE_ADJUSTMENT
;
396 TA_LOG(("-- ref = %ld, shoot = %ld\n", *blue_ref
, *blue_shoot
));
405 /* check whether all ASCII digits have the same advance width */
408 ta_latin_metrics_check_digits(TA_LatinMetrics metrics
,
412 FT_Bool started
= 0, same_width
= 1;
413 FT_Fixed advance
, old_advance
= 0;
416 /* digit `0' is 0x30 in all supported charmaps */
417 for (i
= 0x30; i
<= 0x39; i
++)
422 glyph_index
= FT_Get_Char_Index(face
, i
);
423 if (glyph_index
== 0)
426 if (FT_Get_Advance(face
, glyph_index
,
429 | FT_LOAD_IGNORE_TRANSFORM
,
435 if (advance
!= old_advance
)
443 old_advance
= advance
;
448 metrics
->root
.digits_have_same_width
= same_width
;
452 /* initialize global metrics */
455 ta_latin_metrics_init(TA_LatinMetrics metrics
,
458 FT_Error error
= FT_Err_Ok
;
459 FT_CharMap oldmap
= face
->charmap
;
462 static const FT_Encoding latin_encodings
[] =
465 FT_ENCODING_APPLE_ROMAN
,
466 FT_ENCODING_ADOBE_STANDARD
,
467 FT_ENCODING_ADOBE_LATIN_1
,
469 FT_ENCODING_NONE
/* end of list */
473 metrics
->units_per_em
= face
->units_per_EM
;
475 /* do we have a latin charmap in there? */
476 for (ee
= 0; latin_encodings
[ee
] != FT_ENCODING_NONE
; ee
++)
478 error
= FT_Select_Charmap(face
, latin_encodings
[ee
]);
485 /* for now, compute the standard width and height from the `o' */
486 ta_latin_metrics_init_widths(metrics
, face
, 'o');
487 ta_latin_metrics_init_blues(metrics
, face
);
488 ta_latin_metrics_check_digits(metrics
, face
);
491 FT_Set_Charmap(face
, oldmap
);
496 /* adjust scaling value, then scale and shift widths */
497 /* and blue zones (if applicable) for given dimension */
500 ta_latin_metrics_scale_dim(TA_LatinMetrics metrics
,
510 if (dim
== TA_DIMENSION_HORZ
)
512 scale
= scaler
->x_scale
;
513 delta
= scaler
->x_delta
;
517 scale
= scaler
->y_scale
;
518 delta
= scaler
->y_delta
;
521 axis
= &metrics
->axis
[dim
];
523 if (axis
->org_scale
== scale
&& axis
->org_delta
== delta
)
526 axis
->org_scale
= scale
;
527 axis
->org_delta
= delta
;
529 /* correct X and Y scale to optimize the alignment of the top of */
530 /* small letters to the pixel grid */
532 TA_LatinAxis Axis
= &metrics
->axis
[TA_DIMENSION_VERT
];
533 TA_LatinBlue blue
= NULL
;
536 for (nn
= 0; nn
< Axis
->blue_count
; nn
++)
538 if (Axis
->blues
[nn
].flags
& TA_LATIN_BLUE_ADJUSTMENT
)
540 blue
= &Axis
->blues
[nn
];
547 FT_Pos scaled
= FT_MulFix(blue
->shoot
.org
, scaler
->y_scale
);
548 FT_Pos fitted
= (scaled
+ 40) & ~63;
551 if (scaled
!= fitted
)
553 if (dim
== TA_DIMENSION_VERT
)
554 scale
= FT_MulDiv(scale
, fitted
, scaled
);
562 if (dim
== TA_DIMENSION_HORZ
)
564 metrics
->root
.scaler
.x_scale
= scale
;
565 metrics
->root
.scaler
.x_delta
= delta
;
569 metrics
->root
.scaler
.y_scale
= scale
;
570 metrics
->root
.scaler
.y_delta
= delta
;
573 /* scale the widths */
574 for (nn
= 0; nn
< axis
->width_count
; nn
++)
576 TA_Width width
= axis
->widths
+ nn
;
579 width
->cur
= FT_MulFix(width
->org
, scale
);
580 width
->fit
= width
->cur
;
583 /* an extra-light axis corresponds to a standard width that is */
584 /* smaller than 5/8 pixels */
586 (FT_Bool
)(FT_MulFix(axis
->standard_width
, scale
) < 32 + 8);
588 if (dim
== TA_DIMENSION_VERT
)
590 /* scale the blue zones */
591 for (nn
= 0; nn
< axis
->blue_count
; nn
++)
593 TA_LatinBlue blue
= &axis
->blues
[nn
];
597 blue
->ref
.cur
= FT_MulFix(blue
->ref
.org
, scale
) + delta
;
598 blue
->ref
.fit
= blue
->ref
.cur
;
599 blue
->shoot
.cur
= FT_MulFix(blue
->shoot
.org
, scale
) + delta
;
600 blue
->shoot
.fit
= blue
->shoot
.cur
;
601 blue
->flags
&= ~TA_LATIN_BLUE_ACTIVE
;
603 /* a blue zone is only active if it is less than 3/4 pixels tall */
604 dist
= FT_MulFix(blue
->ref
.org
- blue
->shoot
.org
, scale
);
605 if (dist
<= 48 && dist
>= -48)
613 /* use discrete values for blue zone widths */
616 /* generic, original code */
617 delta1
= blue
->shoot
.org
- blue
->ref
.org
;
622 delta2
= FT_MulFix(delta2
, scale
);
626 else if (delta2
< 64)
627 delta2
= 32 + (((delta2
- 32) + 16) & ~31);
629 delta2
= TA_PIX_ROUND(delta2
);
634 blue
->ref
.fit
= TA_PIX_ROUND(blue
->ref
.cur
);
635 blue
->shoot
.fit
= blue
->ref
.fit
+ delta2
;
637 /* simplified version due to abs(dist) <= 48 */
652 blue
->ref
.fit
= TA_PIX_ROUND(blue
->ref
.cur
);
653 blue
->shoot
.fit
= blue
->ref
.fit
- delta2
;
656 blue
->flags
|= TA_LATIN_BLUE_ACTIVE
;
663 /* scale global values in both directions */
666 ta_latin_metrics_scale(TA_LatinMetrics metrics
,
669 metrics
->root
.scaler
.render_mode
= scaler
->render_mode
;
670 metrics
->root
.scaler
.face
= scaler
->face
;
672 ta_latin_metrics_scale_dim(metrics
, scaler
, TA_DIMENSION_HORZ
);
673 ta_latin_metrics_scale_dim(metrics
, scaler
, TA_DIMENSION_VERT
);
677 /* walk over all contours and compute its segments */
680 ta_latin_hints_compute_segments(TA_GlyphHints hints
,
683 TA_AxisHints axis
= &hints
->axis
[dim
];
684 FT_Error error
= FT_Err_Ok
;
686 TA_Segment segment
= NULL
;
689 TA_Point
* contour
= hints
->contours
;
690 TA_Point
* contour_limit
= contour
+ hints
->num_contours
;
691 TA_Direction major_dir
, segment_dir
;
694 memset(&seg0
, 0, sizeof (TA_SegmentRec
));
696 seg0
.flags
= TA_EDGE_NORMAL
;
698 major_dir
= (TA_Direction
)TA_ABS(axis
->major_dir
);
699 segment_dir
= major_dir
;
701 axis
->num_segments
= 0;
703 /* set up (u,v) in each point */
704 if (dim
== TA_DIMENSION_HORZ
)
706 TA_Point point
= hints
->points
;
707 TA_Point limit
= point
+ hints
->num_points
;
710 for (; point
< limit
; point
++)
712 point
->u
= point
->fx
;
713 point
->v
= point
->fy
;
718 TA_Point point
= hints
->points
;
719 TA_Point limit
= point
+ hints
->num_points
;
722 for (; point
< limit
; point
++)
724 point
->u
= point
->fy
;
725 point
->v
= point
->fx
;
729 /* do each contour separately */
730 for (; contour
< contour_limit
; contour
++)
732 TA_Point point
= contour
[0];
733 TA_Point last
= point
->prev
;
737 FT_Pos min_pos
= 32000; /* minimum segment pos != min_coord */
738 FT_Pos max_pos
= -32000; /* maximum segment pos != max_coord */
742 if (point
== last
) /* skip singletons -- just in case */
745 if (TA_ABS(last
->out_dir
) == major_dir
746 && TA_ABS(point
->out_dir
) == major_dir
)
748 /* we are already on an edge, try to locate its start */
754 if (TA_ABS(point
->out_dir
) != major_dir
)
780 if (point
->out_dir
!= segment_dir
783 /* we are just leaving an edge; record a new segment! */
784 segment
->last
= point
;
785 segment
->pos
= (FT_Short
)((min_pos
+ max_pos
) >> 1);
787 /* a segment is round if either its first or last point */
788 /* is a control point */
789 if ((segment
->first
->flags
| point
->flags
) & TA_FLAG_CONTROL
)
790 segment
->flags
|= TA_EDGE_ROUND
;
792 /* compute segment size */
793 min_pos
= max_pos
= point
->v
;
795 v
= segment
->first
->v
;
801 segment
->min_coord
= (FT_Short
)min_pos
;
802 segment
->max_coord
= (FT_Short
)max_pos
;
803 segment
->height
= (FT_Short
)(segment
->max_coord
-
812 /* now exit if we are at the start/end point */
821 && TA_ABS(point
->out_dir
) == major_dir
)
823 /* this is the start of a new segment! */
824 segment_dir
= (TA_Direction
)point
->out_dir
;
826 /* clear all segment fields */
827 error
= ta_axis_hints_new_segment(axis
, &segment
);
832 segment
->dir
= (FT_Char
)segment_dir
;
833 min_pos
= max_pos
= point
->u
;
834 segment
->first
= point
;
835 segment
->last
= point
;
844 /* now slightly increase the height of segments if this makes sense -- */
845 /* this is used to better detect and ignore serifs */
847 TA_Segment segments
= axis
->segments
;
848 TA_Segment segments_end
= segments
+ axis
->num_segments
;
851 for (segment
= segments
; segment
< segments_end
; segment
++)
853 TA_Point first
= segment
->first
;
854 TA_Point last
= segment
->last
;
856 FT_Pos first_v
= first
->v
;
857 FT_Pos last_v
= last
->v
;
863 if (first_v
< last_v
)
870 segment
->height
= (FT_Short
)(segment
->height
+
871 ((first_v
- p
->v
) >> 1));
875 segment
->height
= (FT_Short
)(segment
->height
+
876 ((p
->v
- last_v
) >> 1));
885 segment
->height
= (FT_Short
)(segment
->height
+
886 ((p
->v
- first_v
) >> 1));
890 segment
->height
= (FT_Short
)(segment
->height
+
891 ((last_v
- p
->v
) >> 1));
901 /* link segments to form stems and serifs */
904 ta_latin_hints_link_segments(TA_GlyphHints hints
,
907 TA_AxisHints axis
= &hints
->axis
[dim
];
909 TA_Segment segments
= axis
->segments
;
910 TA_Segment segment_limit
= segments
+ axis
->num_segments
;
912 FT_Pos len_threshold
, len_score
;
913 TA_Segment seg1
, seg2
;
916 len_threshold
= TA_LATIN_CONSTANT(hints
->metrics
, 8);
917 if (len_threshold
== 0)
920 len_score
= TA_LATIN_CONSTANT(hints
->metrics
, 6000);
922 /* now compare each segment to the others */
923 for (seg1
= segments
; seg1
< segment_limit
; seg1
++)
925 /* the fake segments are introduced to hint the metrics -- */
926 /* we must never link them to anything */
927 if (seg1
->dir
!= axis
->major_dir
928 || seg1
->first
== seg1
->last
)
931 /* search for stems having opposite directions, */
932 /* with seg1 to the `left' of seg2 */
933 for (seg2
= segments
; seg2
< segment_limit
; seg2
++)
935 FT_Pos pos1
= seg1
->pos
;
936 FT_Pos pos2
= seg2
->pos
;
939 if (seg1
->dir
+ seg2
->dir
== 0
942 /* compute distance between the two segments */
943 FT_Pos dist
= pos2
- pos1
;
944 FT_Pos min
= seg1
->min_coord
;
945 FT_Pos max
= seg1
->max_coord
;
949 if (min
< seg2
->min_coord
)
950 min
= seg2
->min_coord
;
951 if (max
> seg2
->max_coord
)
952 max
= seg2
->max_coord
;
954 /* compute maximum coordinate difference of the two segments */
956 if (len
>= len_threshold
)
958 /* small coordinate differences cause a higher score, and */
959 /* segments with a greater distance cause a higher score also */
960 score
= dist
+ len_score
/ len
;
962 /* and we search for the smallest score */
963 /* of the sum of the two values */
964 if (score
< seg1
->score
)
970 if (score
< seg2
->score
)
980 /* now compute the `serif' segments, cf. explanations in `tahints.h' */
981 for (seg1
= segments
; seg1
< segment_limit
; seg1
++)
987 if (seg2
->link
!= seg1
)
990 seg1
->serif
= seg2
->link
;
997 /* link segments to edges, using feature analysis for selection */
1000 ta_latin_hints_compute_edges(TA_GlyphHints hints
,
1003 TA_AxisHints axis
= &hints
->axis
[dim
];
1004 FT_Error error
= FT_Err_Ok
;
1005 TA_LatinAxis laxis
= &((TA_LatinMetrics
)hints
->metrics
)->axis
[dim
];
1007 TA_Segment segments
= axis
->segments
;
1008 TA_Segment segment_limit
= segments
+ axis
->num_segments
;
1012 TA_Direction up_dir
;
1015 FT_Pos edge_distance_threshold
;
1016 FT_Pos segment_length_threshold
;
1019 axis
->num_edges
= 0;
1021 scale
= (dim
== TA_DIMENSION_HORZ
) ? hints
->x_scale
1025 up_dir
= (dim
== TA_DIMENSION_HORZ
) ? TA_DIR_UP
1029 /* we ignore all segments that are less than 1 pixel in length */
1030 /* to avoid many problems with serif fonts */
1031 /* (the corresponding threshold is computed in font units) */
1032 if (dim
== TA_DIMENSION_HORZ
)
1033 segment_length_threshold
= FT_DivFix(64, hints
->y_scale
);
1035 segment_length_threshold
= 0;
1037 /********************************************************************/
1039 /* We begin by generating a sorted table of edges for the current */
1040 /* direction. To do so, we simply scan each segment and try to find */
1041 /* an edge in our table that corresponds to its position. */
1043 /* If no edge is found, we create and insert a new edge in the */
1044 /* sorted table. Otherwise, we simply add the segment to the edge's */
1045 /* list which gets processed in the second step to compute the */
1046 /* edge's properties. */
1048 /* Note that the table of edges is sorted along the segment/edge */
1051 /********************************************************************/
1053 /* assure that edge distance threshold is at most 0.25px */
1054 edge_distance_threshold
= FT_MulFix(laxis
->edge_distance_threshold
,
1056 if (edge_distance_threshold
> 64 / 4)
1057 edge_distance_threshold
= 64 / 4;
1059 edge_distance_threshold
= FT_DivFix(edge_distance_threshold
,
1062 for (seg
= segments
; seg
< segment_limit
; seg
++)
1064 TA_Edge found
= NULL
;
1068 if (seg
->height
< segment_length_threshold
)
1071 /* a special case for serif edges: */
1072 /* if they are smaller than 1.5 pixels we ignore them */
1074 && 2 * seg
->height
< 3 * segment_length_threshold
)
1077 /* look for an edge corresponding to the segment */
1078 for (ee
= 0; ee
< axis
->num_edges
; ee
++)
1080 TA_Edge edge
= axis
->edges
+ ee
;
1084 dist
= seg
->pos
- edge
->fpos
;
1088 if (dist
< edge_distance_threshold
&& edge
->dir
== seg
->dir
)
1100 /* insert a new edge in the list and sort according to the position */
1101 error
= ta_axis_hints_new_edge(axis
, seg
->pos
,
1102 (TA_Direction
)seg
->dir
,
1107 /* add the segment to the new edge's list */
1108 memset(edge
, 0, sizeof (TA_EdgeRec
));
1111 edge
->dir
= seg
->dir
;
1112 edge
->fpos
= seg
->pos
;
1113 edge
->opos
= FT_MulFix(seg
->pos
, scale
);
1114 edge
->pos
= edge
->opos
;
1115 seg
->edge_next
= seg
;
1119 /* if an edge was found, simply add the segment to the edge's list */
1120 seg
->edge_next
= found
->first
;
1121 found
->last
->edge_next
= seg
;
1126 /*****************************************************************/
1128 /* Good, we now compute each edge's properties according to */
1129 /* the segments found on its position. Basically, these are */
1131 /* - the edge's main direction */
1132 /* - stem edge, serif edge or both (which defaults to stem then) */
1133 /* - rounded edge, straight or both (which defaults to straight) */
1134 /* - link for edge */
1136 /*****************************************************************/
1138 /* first of all, set the `edge' field in each segment -- this is */
1139 /* required in order to compute edge links */
1141 /* note that removing this loop and setting the `edge' field of each */
1142 /* segment directly in the code above slows down execution speed for */
1143 /* some reasons on platforms like the Sun */
1145 TA_Edge edges
= axis
->edges
;
1146 TA_Edge edge_limit
= edges
+ axis
->num_edges
;
1150 for (edge
= edges
; edge
< edge_limit
; edge
++)
1157 seg
= seg
->edge_next
;
1158 } while (seg
!= edge
->first
);
1161 /* now compute each edge properties */
1162 for (edge
= edges
; edge
< edge_limit
; edge
++)
1164 FT_Int is_round
= 0; /* does it contain round segments? */
1165 FT_Int is_straight
= 0; /* does it contain straight segments? */
1167 FT_Pos ups
= 0; /* number of upwards segments */
1168 FT_Pos downs
= 0; /* number of downwards segments */
1179 /* check for roundness of segment */
1180 if (seg
->flags
& TA_EDGE_ROUND
)
1186 /* check for segment direction */
1187 if (seg
->dir
== up_dir
)
1188 ups
+= seg
->max_coord
- seg
->min_coord
;
1190 downs
+= seg
->max_coord
- seg
->min_coord
;
1193 /* check for links -- */
1194 /* if seg->serif is set, then seg->link must be ignored */
1195 is_serif
= (FT_Bool
)(seg
->serif
1197 && seg
->serif
->edge
!= edge
);
1199 if ((seg
->link
&& seg
->link
->edge
!= NULL
)
1212 edge2
= edge
->serif
;
1221 edge_delta
= edge
->fpos
- edge2
->fpos
;
1223 edge_delta
= -edge_delta
;
1225 seg_delta
= seg
->pos
- seg2
->pos
;
1227 seg_delta
= -seg_delta
;
1229 if (seg_delta
< edge_delta
)
1237 edge
->serif
= edge2
;
1238 edge2
->flags
|= TA_EDGE_SERIF
;
1244 seg
= seg
->edge_next
;
1245 } while (seg
!= edge
->first
);
1247 /* set the round/straight flags */
1248 edge
->flags
= TA_EDGE_NORMAL
;
1251 && is_round
>= is_straight
)
1252 edge
->flags
|= TA_EDGE_ROUND
;
1255 /* set the edge's main direction */
1256 edge
->dir
= TA_DIR_NONE
;
1259 edge
->dir
= (FT_Char
)up_dir
;
1261 else if (ups
< downs
)
1262 edge
->dir
= (FT_Char
)-up_dir
;
1264 else if (ups
== downs
)
1265 edge
->dir
= 0; /* both up and down! */
1268 /* get rid of serifs if link is set */
1269 /* XXX: this gets rid of many unpleasant artefacts! */
1270 /* example: the `c' in cour.pfa at size 13 */
1272 if (edge
->serif
&& edge
->link
)
1282 /* detect segments and edges for given dimension */
1285 ta_latin_hints_detect_features(TA_GlyphHints hints
,
1291 error
= ta_latin_hints_compute_segments(hints
, dim
);
1294 ta_latin_hints_link_segments(hints
, dim
);
1296 error
= ta_latin_hints_compute_edges(hints
, dim
);
1303 /* compute all edges which lie within blue zones */
1306 ta_latin_hints_compute_blue_edges(TA_GlyphHints hints
,
1307 TA_LatinMetrics metrics
)
1309 TA_AxisHints axis
= &hints
->axis
[TA_DIMENSION_VERT
];
1311 TA_Edge edge
= axis
->edges
;
1312 TA_Edge edge_limit
= edge
+ axis
->num_edges
;
1314 TA_LatinAxis latin
= &metrics
->axis
[TA_DIMENSION_VERT
];
1315 FT_Fixed scale
= latin
->scale
;
1318 /* compute which blue zones are active, */
1319 /* i.e. have their scaled size < 3/4 pixels */
1321 /* for each horizontal edge search the blue zone which is closest */
1322 for (; edge
< edge_limit
; edge
++)
1325 TA_Width best_blue
= NULL
;
1326 FT_Pos best_dist
; /* initial threshold */
1328 FT_UInt best_blue_idx
= 0;
1329 FT_Bool best_blue_is_shoot
= 0;
1332 /* compute the initial threshold as a fraction of the EM size */
1333 /* (the value 40 is heuristic) */
1334 best_dist
= FT_MulFix(metrics
->units_per_em
/ 40, scale
);
1336 /* assure a minimum distance of 0.5px */
1337 if (best_dist
> 64 / 2)
1340 for (bb
= 0; bb
< TA_LATIN_BLUE_MAX
; bb
++)
1342 TA_LatinBlue blue
= latin
->blues
+ bb
;
1343 FT_Bool is_top_blue
, is_major_dir
;
1346 /* skip inactive blue zones (i.e., those that are too large) */
1347 if (!(blue
->flags
& TA_LATIN_BLUE_ACTIVE
))
1350 /* if it is a top zone, check for right edges -- */
1351 /* if it is a bottom zone, check for left edges */
1352 is_top_blue
= (FT_Byte
)((blue
->flags
& TA_LATIN_BLUE_TOP
) != 0);
1353 is_major_dir
= FT_BOOL(edge
->dir
== axis
->major_dir
);
1355 /* if it is a top zone, the edge must be against the major */
1356 /* direction; if it is a bottom zone, it must be in the major */
1358 if (is_top_blue
^ is_major_dir
)
1363 /* first of all, compare it to the reference position */
1364 dist
= edge
->fpos
- blue
->ref
.org
;
1368 dist
= FT_MulFix(dist
, scale
);
1369 if (dist
< best_dist
)
1372 best_blue
= &blue
->ref
;
1375 best_blue_is_shoot
= 0;
1378 /* now compare it to the overshoot position and check whether */
1379 /* the edge is rounded, and whether the edge is over the */
1380 /* reference position of a top zone, or under the reference */
1381 /* position of a bottom zone */
1382 if (edge
->flags
& TA_EDGE_ROUND
1385 FT_Bool is_under_ref
= FT_BOOL(edge
->fpos
< blue
->ref
.org
);
1388 if (is_top_blue
^ is_under_ref
)
1390 dist
= edge
->fpos
- blue
->shoot
.org
;
1394 dist
= FT_MulFix(dist
, scale
);
1395 if (dist
< best_dist
)
1398 best_blue
= &blue
->shoot
;
1401 best_blue_is_shoot
= 1;
1410 edge
->blue_edge
= best_blue
;
1411 edge
->best_blue_idx
= best_blue_idx
;
1412 edge
->best_blue_is_shoot
= best_blue_is_shoot
;
1418 /* initalize hinting engine */
1421 ta_latin_hints_init(TA_GlyphHints hints
,
1422 TA_LatinMetrics metrics
)
1424 FT_Render_Mode mode
;
1425 FT_UInt32 scaler_flags
, other_flags
;
1426 FT_Face face
= metrics
->root
.scaler
.face
;
1429 ta_glyph_hints_rescale(hints
, (TA_ScriptMetrics
)metrics
);
1431 /* correct x_scale and y_scale if needed, since they may have */
1432 /* been modified by `ta_latin_metrics_scale_dim' above */
1433 hints
->x_scale
= metrics
->axis
[TA_DIMENSION_HORZ
].scale
;
1434 hints
->x_delta
= metrics
->axis
[TA_DIMENSION_HORZ
].delta
;
1435 hints
->y_scale
= metrics
->axis
[TA_DIMENSION_VERT
].scale
;
1436 hints
->y_delta
= metrics
->axis
[TA_DIMENSION_VERT
].delta
;
1438 /* compute flags depending on render mode, etc. */
1439 mode
= metrics
->root
.scaler
.render_mode
;
1441 #if 0 /* #ifdef TA_CONFIG_OPTION_USE_WARPER */
1442 if (mode
== FT_RENDER_MODE_LCD
1443 || mode
== FT_RENDER_MODE_LCD_V
)
1444 metrics
->root
.scaler
.render_mode
=
1445 mode
= FT_RENDER_MODE_NORMAL
;
1448 scaler_flags
= hints
->scaler_flags
;
1451 /* we snap the width of vertical stems for the monochrome */
1452 /* and horizontal LCD rendering targets only */
1453 if (mode
== FT_RENDER_MODE_MONO
1454 || mode
== FT_RENDER_MODE_LCD
)
1455 other_flags
|= TA_LATIN_HINTS_HORZ_SNAP
;
1457 /* we snap the width of horizontal stems for the monochrome */
1458 /* and vertical LCD rendering targets only */
1459 if (mode
== FT_RENDER_MODE_MONO
1460 || mode
== FT_RENDER_MODE_LCD_V
)
1461 other_flags
|= TA_LATIN_HINTS_VERT_SNAP
;
1463 /* we adjust stems to full pixels only if we don't use the `light' mode */
1464 if (mode
!= FT_RENDER_MODE_LIGHT
)
1465 other_flags
|= TA_LATIN_HINTS_STEM_ADJUST
;
1467 if (mode
== FT_RENDER_MODE_MONO
)
1468 other_flags
|= TA_LATIN_HINTS_MONO
;
1470 /* in `light' hinting mode we disable horizontal hinting completely; */
1471 /* we also do it if the face is italic */
1472 if (mode
== FT_RENDER_MODE_LIGHT
1473 || (face
->style_flags
& FT_STYLE_FLAG_ITALIC
) != 0)
1474 scaler_flags
|= TA_SCALER_FLAG_NO_HORIZONTAL
;
1476 hints
->scaler_flags
= scaler_flags
;
1477 hints
->other_flags
= other_flags
;
1483 /* snap a given width in scaled coordinates to */
1484 /* one of the current standard widths */
1487 ta_latin_snap_width(TA_Width widths
,
1492 FT_Pos best
= 64 + 32 + 2;
1493 FT_Pos reference
= width
;
1497 for (n
= 0; n
< count
; n
++)
1514 scaled
= TA_PIX_ROUND(reference
);
1516 if (width
>= reference
)
1518 if (width
< scaled
+ 48)
1523 if (width
> scaled
- 48)
1531 /* compute the snapped width of a given stem, ignoring very thin ones */
1533 /* there is a lot of voodoo in this function; changing the hard-coded */
1534 /* parameters influence the whole hinting process */
1537 ta_latin_compute_stem_width(TA_GlyphHints hints
,
1543 TA_LatinMetrics metrics
= (TA_LatinMetrics
) hints
->metrics
;
1544 TA_LatinAxis axis
= &metrics
->axis
[dim
];
1546 FT_Pos dist
= width
;
1548 FT_Int vertical
= (dim
== TA_DIMENSION_VERT
);
1551 if (!TA_LATIN_HINTS_DO_STEM_ADJUST(hints
)
1552 || axis
->extra_light
)
1561 if ((vertical
&& !TA_LATIN_HINTS_DO_VERT_SNAP(hints
))
1562 || (!vertical
&& !TA_LATIN_HINTS_DO_HORZ_SNAP(hints
)))
1564 /* smooth hinting process: very lightly quantize the stem width */
1566 /* leave the widths of serifs alone */
1567 if ((stem_flags
& TA_EDGE_SERIF
)
1571 else if (base_flags
& TA_EDGE_ROUND
)
1579 if (axis
->width_count
> 0)
1584 /* compare to standard width */
1585 delta
= dist
- axis
->widths
[0].cur
;
1592 dist
= axis
->widths
[0].cur
;
1606 else if (delta
< 32)
1608 else if (delta
< 54)
1614 dist
= (dist
+ 32) & ~63;
1619 /* strong hinting process: snap the stem width to integer pixels */
1621 FT_Pos org_dist
= dist
;
1624 dist
= ta_latin_snap_width(axis
->widths
, axis
->width_count
, dist
);
1628 /* in the case of vertical hinting, */
1629 /* always round the stem heights to integer pixels */
1632 dist
= (dist
+ 16) & ~63;
1638 if (TA_LATIN_HINTS_DO_MONO(hints
))
1640 /* monochrome horizontal hinting: */
1641 /* snap widths to integer pixels with a different threshold */
1646 dist
= (dist
+ 32) & ~63;
1650 /* for horizontal anti-aliased hinting, we adopt a more subtle */
1651 /* approach: we strengthen small stems, round stems whose size */
1652 /* is between 1 and 2 pixels to an integer, otherwise nothing */
1655 dist
= (dist
+ 64) >> 1;
1657 else if (dist
< 128)
1659 /* we only round to an integer width if the corresponding */
1660 /* distortion is less than 1/4 pixel -- otherwise, this */
1661 /* makes everything worse since the diagonals, which are */
1662 /* not hinted, appear a lot bolder or thinner than the */
1663 /* vertical stems */
1668 dist
= (dist
+ 22) & ~63;
1669 delta
= dist
- org_dist
;
1677 dist
= (dist
+ 64) >> 1;
1681 /* round otherwise to prevent color fringes in LCD mode */
1682 dist
= (dist
+ 32) & ~63;
1695 /* align one stem edge relative to the previous stem edge */
1698 ta_latin_align_linked_edge(TA_GlyphHints hints
,
1703 FT_Pos dist
= stem_edge
->opos
- base_edge
->opos
;
1705 FT_Pos fitted_width
= ta_latin_compute_stem_width(
1711 stem_edge
->pos
= base_edge
->pos
+ fitted_width
;
1713 TA_LOG((" LINK: edge %d (opos=%.2f) linked to %.2f,"
1714 " dist was %.2f, now %.2f\n",
1715 stem_edge
- hints
->axis
[dim
].edges
, stem_edge
->opos
/ 64.0,
1716 stem_edge
->pos
/ 64.0, dist
/ 64.0, fitted_width
/ 64.0));
1718 if (hints
->recorder
)
1719 hints
->recorder(ta_link
, hints
, dim
,
1720 base_edge
, stem_edge
, NULL
, NULL
, NULL
);
1724 /* shift the coordinates of the `serif' edge by the same amount */
1725 /* as the corresponding `base' edge has been moved already */
1728 ta_latin_align_serif_edge(TA_GlyphHints hints
,
1734 serif
->pos
= base
->pos
+ (serif
->opos
- base
->opos
);
1738 /* the main grid-fitting routine */
1741 ta_latin_hint_edges(TA_GlyphHints hints
,
1744 TA_AxisHints axis
= &hints
->axis
[dim
];
1746 TA_Edge edges
= axis
->edges
;
1747 TA_Edge edge_limit
= edges
+ axis
->num_edges
;
1751 TA_Edge anchor
= NULL
;
1752 FT_Int has_serifs
= 0;
1755 TA_LOG(("%s edge hinting\n", dim
== TA_DIMENSION_VERT
? "horizontal"
1758 /* we begin by aligning all stems relative to the blue zone if needed -- */
1759 /* that's only for horizontal edges */
1761 if (dim
== TA_DIMENSION_VERT
1762 && TA_HINTS_DO_BLUES(hints
))
1764 for (edge
= edges
; edge
< edge_limit
; edge
++)
1767 TA_Edge edge1
, edge2
; /* these edges form the stem to check */
1770 if (edge
->flags
& TA_EDGE_DONE
)
1773 blue
= edge
->blue_edge
;
1780 /* flip edges if the other stem is aligned to a blue zone */
1781 else if (edge2
&& edge2
->blue_edge
)
1783 blue
= edge2
->blue_edge
;
1792 TA_LOG((" BLUE_ANCHOR: edge %d (opos=%.2f) snapped to %.2f,"
1793 " was %.2f (anchor=edge %d)\n",
1794 edge1
- edges
, edge1
->opos
/ 64.0, blue
->fit
/ 64.0,
1795 edge1
->pos
/ 64.0, edge
- edges
));
1797 TA_LOG((" BLUE: edge %d (opos=%.2f) snapped to %.2f, was %.2f\n",
1798 edge1
- edges
, edge1
->opos
/ 64.0, blue
->fit
/ 64.0,
1799 edge1
->pos
/ 64.0));
1801 edge1
->pos
= blue
->fit
;
1802 edge1
->flags
|= TA_EDGE_DONE
;
1804 if (hints
->recorder
)
1807 hints
->recorder(ta_blue_anchor
, hints
, dim
,
1808 edge1
, edge
, NULL
, NULL
, NULL
);
1810 hints
->recorder(ta_blue
, hints
, dim
,
1811 edge1
, NULL
, NULL
, NULL
, NULL
);
1814 if (edge2
&& !edge2
->blue_edge
)
1816 ta_latin_align_linked_edge(hints
, dim
, edge1
, edge2
);
1817 edge2
->flags
|= TA_EDGE_DONE
;
1825 /* now we align all other stem edges, */
1826 /* trying to maintain the relative order of stems in the glyph */
1827 for (edge
= edges
; edge
< edge_limit
; edge
++)
1832 if (edge
->flags
& TA_EDGE_DONE
)
1835 /* skip all non-stem edges */
1843 /* now align the stem */
1845 /* this should not happen, but it's better to be safe */
1846 if (edge2
->blue_edge
)
1848 TA_LOG((" ASSERTION FAILED for edge %d\n", edge2
-edges
));
1850 ta_latin_align_linked_edge(hints
, dim
, edge2
, edge
);
1851 edge
->flags
|= TA_EDGE_DONE
;
1857 /* if we reach this if clause, no stem has been aligned yet */
1859 FT_Pos org_len
, org_center
, cur_len
;
1860 FT_Pos cur_pos1
, error1
, error2
, u_off
, d_off
;
1863 org_len
= edge2
->opos
- edge
->opos
;
1864 cur_len
= ta_latin_compute_stem_width(hints
, dim
, org_len
,
1865 edge
->flags
, edge2
->flags
);
1867 /* some voodoo to specially round edges for small stem widths; */
1868 /* the idea is to align the center of a stem, */
1869 /* then shifting the stem edges to suitable positions */
1878 /* 1px < width < 1.5px */
1885 org_center
= edge
->opos
+ (org_len
>> 1);
1886 cur_pos1
= TA_PIX_ROUND(org_center
);
1888 error1
= org_center
- (cur_pos1
- u_off
);
1892 error2
= org_center
- (cur_pos1
+ d_off
);
1896 if (error1
< error2
)
1901 edge
->pos
= cur_pos1
- cur_len
/ 2;
1902 edge2
->pos
= edge
->pos
+ cur_len
;
1905 edge
->pos
= TA_PIX_ROUND(edge
->opos
);
1908 edge
->flags
|= TA_EDGE_DONE
;
1910 TA_LOG((" ANCHOR: edge %d (opos=%.2f) and %d (opos=%.2f)"
1911 " snapped to %.2f and %.2f\n",
1912 edge
- edges
, edge
->opos
/ 64.0,
1913 edge2
- edges
, edge2
->opos
/ 64.0,
1914 edge
->pos
/ 64.0, edge2
->pos
/ 64.0));
1916 if (hints
->recorder
)
1917 hints
->recorder(ta_anchor
, hints
, dim
,
1918 edge
, edge2
, NULL
, NULL
, NULL
);
1920 ta_latin_align_linked_edge(hints
, dim
, edge
, edge2
);
1924 FT_Pos org_pos
, org_len
, org_center
, cur_len
;
1925 FT_Pos cur_pos1
, cur_pos2
, delta1
, delta2
;
1928 org_pos
= anchor
->pos
+ (edge
->opos
- anchor
->opos
);
1929 org_len
= edge2
->opos
- edge
->opos
;
1930 org_center
= org_pos
+ (org_len
>> 1);
1932 cur_len
= ta_latin_compute_stem_width(hints
, dim
, org_len
,
1933 edge
->flags
, edge2
->flags
);
1935 if (edge2
->flags
& TA_EDGE_DONE
)
1937 TA_LOG((" ADJUST: edge %d (pos=%.2f) moved to %.2f\n",
1938 edge
- edges
, edge
->pos
/ 64.0,
1939 (edge2
->pos
- cur_len
) / 64.0));
1941 edge
->pos
= edge2
->pos
- cur_len
;
1943 if (hints
->recorder
)
1945 TA_Edge bound
= NULL
;
1951 hints
->recorder(ta_adjust
, hints
, dim
,
1952 edge
, edge2
, NULL
, bound
, NULL
);
1956 else if (cur_len
< 96)
1958 FT_Pos u_off
, d_off
;
1961 cur_pos1
= TA_PIX_ROUND(org_center
);
1974 delta1
= org_center
- (cur_pos1
- u_off
);
1978 delta2
= org_center
- (cur_pos1
+ d_off
);
1982 if (delta1
< delta2
)
1987 edge
->pos
= cur_pos1
- cur_len
/ 2;
1988 edge2
->pos
= cur_pos1
+ cur_len
/ 2;
1990 TA_LOG((" STEM: edge %d (opos=%.2f) linked to %d (opos=%.2f)"
1991 " snapped to %.2f and %.2f\n",
1992 edge
- edges
, edge
->opos
/ 64.0,
1993 edge2
- edges
, edge2
->opos
/ 64.0,
1994 edge
->pos
/ 64.0, edge2
->pos
/ 64.0));
1996 if (hints
->recorder
)
1998 TA_Edge bound
= NULL
;
2004 hints
->recorder(ta_stem
, hints
, dim
,
2005 edge
, edge2
, NULL
, bound
, NULL
);
2011 org_pos
= anchor
->pos
+ (edge
->opos
- anchor
->opos
);
2012 org_len
= edge2
->opos
- edge
->opos
;
2013 org_center
= org_pos
+ (org_len
>> 1);
2015 cur_len
= ta_latin_compute_stem_width(hints
, dim
, org_len
,
2016 edge
->flags
, edge2
->flags
);
2018 cur_pos1
= TA_PIX_ROUND(org_pos
);
2019 delta1
= cur_pos1
+ (cur_len
>> 1) - org_center
;
2023 cur_pos2
= TA_PIX_ROUND(org_pos
+ org_len
) - cur_len
;
2024 delta2
= cur_pos2
+ (cur_len
>> 1) - org_center
;
2028 edge
->pos
= (delta1
< delta2
) ? cur_pos1
: cur_pos2
;
2029 edge2
->pos
= edge
->pos
+ cur_len
;
2031 TA_LOG((" STEM: edge %d (opos=%.2f) linked to %d (opos=%.2f)"
2032 " snapped to %.2f and %.2f\n",
2033 edge
- edges
, edge
->opos
/ 64.0,
2034 edge2
- edges
, edge2
->opos
/ 64.0,
2035 edge
->pos
/ 64.0, edge2
->pos
/ 64.0));
2037 if (hints
->recorder
)
2039 TA_Edge bound
= NULL
;
2045 hints
->recorder(ta_stem
, hints
, dim
,
2046 edge
, edge2
, NULL
, bound
, NULL
);
2050 edge
->flags
|= TA_EDGE_DONE
;
2051 edge2
->flags
|= TA_EDGE_DONE
;
2054 && edge
->pos
< edge
[-1].pos
)
2056 TA_LOG((" BOUND: edge %d (pos=%.2f) moved to %.2f\n",
2057 edge
- edges
, edge
->pos
/ 64.0, edge
[-1].pos
/ 64.0));
2059 edge
->pos
= edge
[-1].pos
;
2061 if (hints
->recorder
)
2062 hints
->recorder(ta_bound
, hints
, dim
,
2063 edge
, &edge
[-1], NULL
, NULL
, NULL
);
2068 /* make sure that lowercase m's maintain their symmetry */
2070 /* In general, lowercase m's have six vertical edges if they are sans */
2071 /* serif, or twelve if they are with serifs. This implementation is */
2072 /* based on that assumption, and seems to work very well with most */
2073 /* faces. However, if for a certain face this assumption is not */
2074 /* true, the m is just rendered like before. In addition, any stem */
2075 /* correction will only be applied to symmetrical glyphs (even if the */
2076 /* glyph is not an m), so the potential for unwanted distortion is */
2077 /* relatively low. */
2079 /* we don't handle horizontal edges since we can't easily assure that */
2080 /* the third (lowest) stem aligns with the base line; it might end up */
2081 /* one pixel higher or lower */
2083 n_edges
= edge_limit
- edges
;
2084 if (dim
== TA_DIMENSION_HORZ
2085 && (n_edges
== 6 || n_edges
== 12))
2087 TA_Edge edge1
, edge2
, edge3
;
2088 FT_Pos dist1
, dist2
, span
, delta
;
2104 dist1
= edge2
->opos
- edge1
->opos
;
2105 dist2
= edge3
->opos
- edge2
->opos
;
2107 span
= dist1
- dist2
;
2113 delta
= edge3
->pos
- (2 * edge2
->pos
- edge1
->pos
);
2114 edge3
->pos
-= delta
;
2116 edge3
->link
->pos
-= delta
;
2118 /* move the serifs along with the stem */
2121 (edges
+ 8)->pos
-= delta
;
2122 (edges
+ 11)->pos
-= delta
;
2125 edge3
->flags
|= TA_EDGE_DONE
;
2127 edge3
->link
->flags
|= TA_EDGE_DONE
;
2131 if (has_serifs
|| !anchor
)
2133 /* now hint the remaining edges (serifs and single) */
2134 /* in order to complete our processing */
2135 for (edge
= edges
; edge
< edge_limit
; edge
++)
2137 TA_Edge lower_bound
= NULL
;
2138 TA_Edge upper_bound
= NULL
;
2143 if (edge
->flags
& TA_EDGE_DONE
)
2150 delta
= edge
->serif
->opos
- edge
->opos
;
2156 lower_bound
= &edge
[-1];
2158 if (edge
+ 1 < edge_limit
2159 && edge
[1].flags
& TA_EDGE_DONE
)
2160 upper_bound
= &edge
[1];
2163 if (delta
< 64 + 16)
2165 ta_latin_align_serif_edge(hints
, edge
->serif
, edge
);
2167 TA_LOG((" SERIF: edge %d (opos=%.2f) serif to %d (opos=%.2f)"
2168 " aligned to %.2f\n",
2169 edge
- edges
, edge
->opos
/ 64.0,
2170 edge
->serif
- edges
, edge
->serif
->opos
/ 64.0,
2173 if (hints
->recorder
)
2174 hints
->recorder(ta_serif
, hints
, dim
,
2175 edge
, NULL
, NULL
, lower_bound
, upper_bound
);
2179 edge
->pos
= TA_PIX_ROUND(edge
->opos
);
2182 TA_LOG((" SERIF_ANCHOR: edge %d (opos=%.2f) snapped to %.2f\n",
2183 edge
- edges
, edge
->opos
/ 64.0, edge
->pos
/ 64.0));
2185 if (hints
->recorder
)
2186 hints
->recorder(ta_serif_anchor
, hints
, dim
,
2187 edge
, NULL
, NULL
, lower_bound
, upper_bound
);
2191 TA_Edge before
, after
;
2194 for (before
= edge
- 1; before
>= edges
; before
--)
2195 if (before
->flags
& TA_EDGE_DONE
)
2198 for (after
= edge
+ 1; after
< edge_limit
; after
++)
2199 if (after
->flags
& TA_EDGE_DONE
)
2202 if (before
>= edges
&& before
< edge
2203 && after
< edge_limit
&& after
> edge
)
2205 if (after
->opos
== before
->opos
)
2206 edge
->pos
= before
->pos
;
2208 edge
->pos
= before
->pos
+ FT_MulDiv(edge
->opos
- before
->opos
,
2209 after
->pos
- before
->pos
,
2210 after
->opos
- before
->opos
);
2212 TA_LOG((" SERIF_LINK1: edge %d (opos=%.2f) snapped to %.2f"
2213 " from %d (opos=%.2f)\n",
2214 edge
- edges
, edge
->opos
/ 64.0,
2216 before
- edges
, before
->opos
/ 64.0));
2218 if (hints
->recorder
)
2219 hints
->recorder(ta_serif_link1
, hints
, dim
,
2220 edge
, before
, after
, lower_bound
, upper_bound
);
2224 edge
->pos
= anchor
->pos
+ ((edge
->opos
- anchor
->opos
+ 16) & ~31);
2226 TA_LOG((" SERIF_LINK2: edge %d (opos=%.2f) snapped to %.2f\n",
2227 edge
- edges
, edge
->opos
/ 64.0, edge
->pos
/ 64.0));
2229 if (hints
->recorder
)
2230 hints
->recorder(ta_serif_link2
, hints
, dim
,
2231 edge
, NULL
, NULL
, lower_bound
, upper_bound
);
2235 edge
->flags
|= TA_EDGE_DONE
;
2238 && edge
->pos
< edge
[-1].pos
)
2240 TA_LOG((" BOUND: edge %d (pos=%.2f) moved to %.2f\n",
2241 edge
- edges
, edge
->pos
/ 64.0, edge
[-1].pos
/ 64.0));
2243 edge
->pos
= edge
[-1].pos
;
2245 if (hints
->recorder
)
2246 hints
->recorder(ta_bound
, hints
, dim
,
2247 edge
, &edge
[-1], NULL
, NULL
, NULL
);
2250 if (edge
+ 1 < edge_limit
2251 && edge
[1].flags
& TA_EDGE_DONE
2252 && edge
->pos
> edge
[1].pos
)
2254 TA_LOG((" BOUND: edge %d (pos=%.2f) moved to %.2f\n",
2255 edge
- edges
, edge
->pos
/ 64.0, edge
[1].pos
/ 64.0));
2257 edge
->pos
= edge
[1].pos
;
2259 if (hints
->recorder
)
2260 hints
->recorder(ta_bound
, hints
, dim
,
2261 edge
, &edge
[1], NULL
, NULL
, NULL
);
2270 /* apply the complete hinting algorithm to a latin glyph */
2273 ta_latin_hints_apply(TA_GlyphHints hints
,
2274 FT_Outline
* outline
,
2275 TA_LatinMetrics metrics
)
2281 error
= ta_glyph_hints_reload(hints
, outline
);
2285 /* analyze glyph outline */
2286 #ifdef TA_CONFIG_OPTION_USE_WARPER
2287 if (metrics
->root
.scaler
.render_mode
== FT_RENDER_MODE_LIGHT
2288 || TA_HINTS_DO_HORIZONTAL(hints
))
2290 if (TA_HINTS_DO_HORIZONTAL(hints
))
2293 error
= ta_latin_hints_detect_features(hints
, TA_DIMENSION_HORZ
);
2298 if (TA_HINTS_DO_VERTICAL(hints
))
2300 error
= ta_latin_hints_detect_features(hints
, TA_DIMENSION_VERT
);
2304 ta_latin_hints_compute_blue_edges(hints
, metrics
);
2307 /* grid-fit the outline */
2308 for (dim
= 0; dim
< TA_DIMENSION_MAX
; dim
++)
2310 #ifdef TA_CONFIG_OPTION_USE_WARPER
2311 if (dim
== TA_DIMENSION_HORZ
2312 && metrics
->root
.scaler
.render_mode
== FT_RENDER_MODE_LIGHT
)
2314 TA_WarperRec warper
;
2319 ta_warper_compute(&warper
, hints
, (TA_Dimension
)dim
, &scale
, &delta
);
2320 ta_glyph_hints_scale_dim(hints
, (TA_Dimension
)dim
, scale
, delta
);
2326 if ((dim
== TA_DIMENSION_HORZ
&& TA_HINTS_DO_HORIZONTAL(hints
))
2327 || (dim
== TA_DIMENSION_VERT
&& TA_HINTS_DO_VERTICAL(hints
)))
2329 ta_latin_hint_edges(hints
, (TA_Dimension
)dim
);
2330 ta_glyph_hints_align_edge_points(hints
, (TA_Dimension
)dim
);
2331 ta_glyph_hints_align_strong_points(hints
, (TA_Dimension
)dim
);
2332 ta_glyph_hints_align_weak_points(hints
, (TA_Dimension
)dim
);
2335 ta_glyph_hints_save(hints
, outline
);
2342 /* XXX: this should probably fine tuned to differentiate better between */
2345 static const TA_Script_UniRangeRec ta_latin_uniranges
[] =
2347 TA_UNIRANGE_REC(0x0020UL
, 0x007FUL
), /* Basic Latin (no control chars) */
2348 TA_UNIRANGE_REC(0x00A0UL
, 0x00FFUL
), /* Latin-1 Supplement (no control chars) */
2349 TA_UNIRANGE_REC(0x0100UL
, 0x017FUL
), /* Latin Extended-A */
2350 TA_UNIRANGE_REC(0x0180UL
, 0x024FUL
), /* Latin Extended-B */
2351 TA_UNIRANGE_REC(0x0250UL
, 0x02AFUL
), /* IPA Extensions */
2352 TA_UNIRANGE_REC(0x02B0UL
, 0x02FFUL
), /* Spacing Modifier Letters */
2353 TA_UNIRANGE_REC(0x0300UL
, 0x036FUL
), /* Combining Diacritical Marks */
2354 TA_UNIRANGE_REC(0x0370UL
, 0x03FFUL
), /* Greek and Coptic */
2355 TA_UNIRANGE_REC(0x0400UL
, 0x04FFUL
), /* Cyrillic */
2356 TA_UNIRANGE_REC(0x0500UL
, 0x052FUL
), /* Cyrillic Supplement */
2357 TA_UNIRANGE_REC(0x1D00UL
, 0x1D7FUL
), /* Phonetic Extensions */
2358 TA_UNIRANGE_REC(0x1D80UL
, 0x1DBFUL
), /* Phonetic Extensions Supplement */
2359 TA_UNIRANGE_REC(0x1DC0UL
, 0x1DFFUL
), /* Combining Diacritical Marks Supplement */
2360 TA_UNIRANGE_REC(0x1E00UL
, 0x1EFFUL
), /* Latin Extended Additional */
2361 TA_UNIRANGE_REC(0x1F00UL
, 0x1FFFUL
), /* Greek Extended */
2362 TA_UNIRANGE_REC(0x2000UL
, 0x206FUL
), /* General Punctuation */
2363 TA_UNIRANGE_REC(0x2070UL
, 0x209FUL
), /* Superscripts and Subscripts */
2364 TA_UNIRANGE_REC(0x20A0UL
, 0x20CFUL
), /* Currency Symbols */
2365 TA_UNIRANGE_REC(0x2150UL
, 0x218FUL
), /* Number Forms */
2366 TA_UNIRANGE_REC(0x2460UL
, 0x24FFUL
), /* Enclosed Alphanumerics */
2367 TA_UNIRANGE_REC(0x2C60UL
, 0x2C7FUL
), /* Latin Extended-C */
2368 TA_UNIRANGE_REC(0x2DE0UL
, 0x2DFFUL
), /* Cyrillic Extended-A */
2369 TA_UNIRANGE_REC(0xA640UL
, 0xA69FUL
), /* Cyrillic Extended-B */
2370 TA_UNIRANGE_REC(0xA720UL
, 0xA7FFUL
), /* Latin Extended-D */
2371 TA_UNIRANGE_REC(0xFB00UL
, 0xFB06UL
), /* Alphab. Present. Forms (Latin Ligs) */
2372 TA_UNIRANGE_REC(0x1D400UL
, 0x1D7FFUL
), /* Mathematical Alphanumeric Symbols */
2373 TA_UNIRANGE_REC(0UL, 0UL)
2377 const TA_ScriptClassRec ta_latin_script_class
=
2382 sizeof (TA_LatinMetricsRec
),
2384 (TA_Script_InitMetricsFunc
)ta_latin_metrics_init
,
2385 (TA_Script_ScaleMetricsFunc
)ta_latin_metrics_scale
,
2386 (TA_Script_DoneMetricsFunc
)NULL
,
2388 (TA_Script_InitHintsFunc
)ta_latin_hints_init
,
2389 (TA_Script_ApplyHintsFunc
)ta_latin_hints_apply
2392 /* end of talatin.c */