4 * Copyright (C) 2011-2012 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
];
552 scaled
= FT_MulFix(blue
->shoot
.org
, scaler
->y_scale
);
555 if ((scaler
->flags
& TA_SCALER_FLAG_INCREASE_X_HEIGHT
)
556 && metrics
->root
.scaler
.face
->size
->metrics
.x_ppem
< 15
557 && metrics
->root
.scaler
.face
->size
->metrics
.x_ppem
> 5)
560 fitted
= (scaled
+ threshold
) & ~63;
562 if (scaled
!= fitted
)
564 if (dim
== TA_DIMENSION_VERT
)
565 scale
= FT_MulDiv(scale
, fitted
, scaled
);
573 if (dim
== TA_DIMENSION_HORZ
)
575 metrics
->root
.scaler
.x_scale
= scale
;
576 metrics
->root
.scaler
.x_delta
= delta
;
580 metrics
->root
.scaler
.y_scale
= scale
;
581 metrics
->root
.scaler
.y_delta
= delta
;
584 /* scale the widths */
585 for (nn
= 0; nn
< axis
->width_count
; nn
++)
587 TA_Width width
= axis
->widths
+ nn
;
590 width
->cur
= FT_MulFix(width
->org
, scale
);
591 width
->fit
= width
->cur
;
594 /* an extra-light axis corresponds to a standard width that is */
595 /* smaller than 5/8 pixels */
597 (FT_Bool
)(FT_MulFix(axis
->standard_width
, scale
) < 32 + 8);
599 if (dim
== TA_DIMENSION_VERT
)
601 /* scale the blue zones */
602 for (nn
= 0; nn
< axis
->blue_count
; nn
++)
604 TA_LatinBlue blue
= &axis
->blues
[nn
];
608 blue
->ref
.cur
= FT_MulFix(blue
->ref
.org
, scale
) + delta
;
609 blue
->ref
.fit
= blue
->ref
.cur
;
610 blue
->shoot
.cur
= FT_MulFix(blue
->shoot
.org
, scale
) + delta
;
611 blue
->shoot
.fit
= blue
->shoot
.cur
;
612 blue
->flags
&= ~TA_LATIN_BLUE_ACTIVE
;
614 /* a blue zone is only active if it is less than 3/4 pixels tall */
615 dist
= FT_MulFix(blue
->ref
.org
- blue
->shoot
.org
, scale
);
616 if (dist
<= 48 && dist
>= -48)
624 /* use discrete values for blue zone widths */
627 /* generic, original code */
628 delta1
= blue
->shoot
.org
- blue
->ref
.org
;
633 delta2
= FT_MulFix(delta2
, scale
);
637 else if (delta2
< 64)
638 delta2
= 32 + (((delta2
- 32) + 16) & ~31);
640 delta2
= TA_PIX_ROUND(delta2
);
645 blue
->ref
.fit
= TA_PIX_ROUND(blue
->ref
.cur
);
646 blue
->shoot
.fit
= blue
->ref
.fit
+ delta2
;
648 /* simplified version due to abs(dist) <= 48 */
663 blue
->ref
.fit
= TA_PIX_ROUND(blue
->ref
.cur
);
664 blue
->shoot
.fit
= blue
->ref
.fit
- delta2
;
667 blue
->flags
|= TA_LATIN_BLUE_ACTIVE
;
674 /* scale global values in both directions */
677 ta_latin_metrics_scale(TA_LatinMetrics metrics
,
680 metrics
->root
.scaler
.render_mode
= scaler
->render_mode
;
681 metrics
->root
.scaler
.face
= scaler
->face
;
683 ta_latin_metrics_scale_dim(metrics
, scaler
, TA_DIMENSION_HORZ
);
684 ta_latin_metrics_scale_dim(metrics
, scaler
, TA_DIMENSION_VERT
);
688 /* walk over all contours and compute its segments */
691 ta_latin_hints_compute_segments(TA_GlyphHints hints
,
694 TA_AxisHints axis
= &hints
->axis
[dim
];
695 FT_Error error
= FT_Err_Ok
;
697 TA_Segment segment
= NULL
;
700 TA_Point
* contour
= hints
->contours
;
701 TA_Point
* contour_limit
= contour
+ hints
->num_contours
;
702 TA_Direction major_dir
, segment_dir
;
705 memset(&seg0
, 0, sizeof (TA_SegmentRec
));
707 seg0
.flags
= TA_EDGE_NORMAL
;
709 major_dir
= (TA_Direction
)TA_ABS(axis
->major_dir
);
710 segment_dir
= major_dir
;
712 axis
->num_segments
= 0;
714 /* set up (u,v) in each point */
715 if (dim
== TA_DIMENSION_HORZ
)
717 TA_Point point
= hints
->points
;
718 TA_Point limit
= point
+ hints
->num_points
;
721 for (; point
< limit
; point
++)
723 point
->u
= point
->fx
;
724 point
->v
= point
->fy
;
729 TA_Point point
= hints
->points
;
730 TA_Point limit
= point
+ hints
->num_points
;
733 for (; point
< limit
; point
++)
735 point
->u
= point
->fy
;
736 point
->v
= point
->fx
;
740 /* do each contour separately */
741 for (; contour
< contour_limit
; contour
++)
743 TA_Point point
= contour
[0];
744 TA_Point last
= point
->prev
;
748 FT_Pos min_pos
= 32000; /* minimum segment pos != min_coord */
749 FT_Pos max_pos
= -32000; /* maximum segment pos != max_coord */
753 if (point
== last
) /* skip singletons -- just in case */
756 if (TA_ABS(last
->out_dir
) == major_dir
757 && TA_ABS(point
->out_dir
) == major_dir
)
759 /* we are already on an edge, try to locate its start */
765 if (TA_ABS(point
->out_dir
) != major_dir
)
791 if (point
->out_dir
!= segment_dir
794 /* we are just leaving an edge; record a new segment! */
795 segment
->last
= point
;
796 segment
->pos
= (FT_Short
)((min_pos
+ max_pos
) >> 1);
798 /* a segment is round if either its first or last point */
799 /* is a control point */
800 if ((segment
->first
->flags
| point
->flags
) & TA_FLAG_CONTROL
)
801 segment
->flags
|= TA_EDGE_ROUND
;
803 /* compute segment size */
804 min_pos
= max_pos
= point
->v
;
806 v
= segment
->first
->v
;
812 segment
->min_coord
= (FT_Short
)min_pos
;
813 segment
->max_coord
= (FT_Short
)max_pos
;
814 segment
->height
= (FT_Short
)(segment
->max_coord
-
823 /* now exit if we are at the start/end point */
832 && TA_ABS(point
->out_dir
) == major_dir
)
834 /* this is the start of a new segment! */
835 segment_dir
= (TA_Direction
)point
->out_dir
;
837 /* clear all segment fields */
838 error
= ta_axis_hints_new_segment(axis
, &segment
);
843 segment
->dir
= (FT_Char
)segment_dir
;
844 min_pos
= max_pos
= point
->u
;
845 segment
->first
= point
;
846 segment
->last
= point
;
855 /* now slightly increase the height of segments if this makes sense -- */
856 /* this is used to better detect and ignore serifs */
858 TA_Segment segments
= axis
->segments
;
859 TA_Segment segments_end
= segments
+ axis
->num_segments
;
862 for (segment
= segments
; segment
< segments_end
; segment
++)
864 TA_Point first
= segment
->first
;
865 TA_Point last
= segment
->last
;
867 FT_Pos first_v
= first
->v
;
868 FT_Pos last_v
= last
->v
;
874 if (first_v
< last_v
)
881 segment
->height
= (FT_Short
)(segment
->height
+
882 ((first_v
- p
->v
) >> 1));
886 segment
->height
= (FT_Short
)(segment
->height
+
887 ((p
->v
- last_v
) >> 1));
896 segment
->height
= (FT_Short
)(segment
->height
+
897 ((p
->v
- first_v
) >> 1));
901 segment
->height
= (FT_Short
)(segment
->height
+
902 ((last_v
- p
->v
) >> 1));
912 /* link segments to form stems and serifs */
915 ta_latin_hints_link_segments(TA_GlyphHints hints
,
918 TA_AxisHints axis
= &hints
->axis
[dim
];
920 TA_Segment segments
= axis
->segments
;
921 TA_Segment segment_limit
= segments
+ axis
->num_segments
;
923 FT_Pos len_threshold
, len_score
;
924 TA_Segment seg1
, seg2
;
927 len_threshold
= TA_LATIN_CONSTANT(hints
->metrics
, 8);
928 if (len_threshold
== 0)
931 len_score
= TA_LATIN_CONSTANT(hints
->metrics
, 6000);
933 /* now compare each segment to the others */
934 for (seg1
= segments
; seg1
< segment_limit
; seg1
++)
936 /* the fake segments are introduced to hint the metrics -- */
937 /* we must never link them to anything */
938 if (seg1
->dir
!= axis
->major_dir
939 || seg1
->first
== seg1
->last
)
942 /* search for stems having opposite directions, */
943 /* with seg1 to the `left' of seg2 */
944 for (seg2
= segments
; seg2
< segment_limit
; seg2
++)
946 FT_Pos pos1
= seg1
->pos
;
947 FT_Pos pos2
= seg2
->pos
;
950 if (seg1
->dir
+ seg2
->dir
== 0
953 /* compute distance between the two segments */
954 FT_Pos dist
= pos2
- pos1
;
955 FT_Pos min
= seg1
->min_coord
;
956 FT_Pos max
= seg1
->max_coord
;
960 if (min
< seg2
->min_coord
)
961 min
= seg2
->min_coord
;
962 if (max
> seg2
->max_coord
)
963 max
= seg2
->max_coord
;
965 /* compute maximum coordinate difference of the two segments */
967 if (len
>= len_threshold
)
969 /* small coordinate differences cause a higher score, and */
970 /* segments with a greater distance cause a higher score also */
971 score
= dist
+ len_score
/ len
;
973 /* and we search for the smallest score */
974 /* of the sum of the two values */
975 if (score
< seg1
->score
)
981 if (score
< seg2
->score
)
991 /* now compute the `serif' segments, cf. explanations in `tahints.h' */
992 for (seg1
= segments
; seg1
< segment_limit
; seg1
++)
998 if (seg2
->link
!= seg1
)
1001 seg1
->serif
= seg2
->link
;
1008 /* link segments to edges, using feature analysis for selection */
1011 ta_latin_hints_compute_edges(TA_GlyphHints hints
,
1014 TA_AxisHints axis
= &hints
->axis
[dim
];
1015 FT_Error error
= FT_Err_Ok
;
1016 TA_LatinAxis laxis
= &((TA_LatinMetrics
)hints
->metrics
)->axis
[dim
];
1018 TA_Segment segments
= axis
->segments
;
1019 TA_Segment segment_limit
= segments
+ axis
->num_segments
;
1023 TA_Direction up_dir
;
1026 FT_Pos edge_distance_threshold
;
1027 FT_Pos segment_length_threshold
;
1030 axis
->num_edges
= 0;
1032 scale
= (dim
== TA_DIMENSION_HORZ
) ? hints
->x_scale
1036 up_dir
= (dim
== TA_DIMENSION_HORZ
) ? TA_DIR_UP
1040 /* we ignore all segments that are less than 1 pixel in length */
1041 /* to avoid many problems with serif fonts */
1042 /* (the corresponding threshold is computed in font units) */
1043 if (dim
== TA_DIMENSION_HORZ
)
1044 segment_length_threshold
= FT_DivFix(64, hints
->y_scale
);
1046 segment_length_threshold
= 0;
1048 /********************************************************************/
1050 /* We begin by generating a sorted table of edges for the current */
1051 /* direction. To do so, we simply scan each segment and try to find */
1052 /* an edge in our table that corresponds to its position. */
1054 /* If no edge is found, we create and insert a new edge in the */
1055 /* sorted table. Otherwise, we simply add the segment to the edge's */
1056 /* list which gets processed in the second step to compute the */
1057 /* edge's properties. */
1059 /* Note that the table of edges is sorted along the segment/edge */
1062 /********************************************************************/
1064 /* assure that edge distance threshold is at most 0.25px */
1065 edge_distance_threshold
= FT_MulFix(laxis
->edge_distance_threshold
,
1067 if (edge_distance_threshold
> 64 / 4)
1068 edge_distance_threshold
= 64 / 4;
1070 edge_distance_threshold
= FT_DivFix(edge_distance_threshold
,
1073 for (seg
= segments
; seg
< segment_limit
; seg
++)
1075 TA_Edge found
= NULL
;
1079 if (seg
->height
< segment_length_threshold
)
1082 /* a special case for serif edges: */
1083 /* if they are smaller than 1.5 pixels we ignore them */
1085 && 2 * seg
->height
< 3 * segment_length_threshold
)
1088 /* look for an edge corresponding to the segment */
1089 for (ee
= 0; ee
< axis
->num_edges
; ee
++)
1091 TA_Edge edge
= axis
->edges
+ ee
;
1095 dist
= seg
->pos
- edge
->fpos
;
1099 if (dist
< edge_distance_threshold
&& edge
->dir
== seg
->dir
)
1111 /* insert a new edge in the list and sort according to the position */
1112 error
= ta_axis_hints_new_edge(axis
, seg
->pos
,
1113 (TA_Direction
)seg
->dir
,
1118 /* add the segment to the new edge's list */
1119 memset(edge
, 0, sizeof (TA_EdgeRec
));
1122 edge
->dir
= seg
->dir
;
1123 edge
->fpos
= seg
->pos
;
1124 edge
->opos
= FT_MulFix(seg
->pos
, scale
);
1125 edge
->pos
= edge
->opos
;
1126 seg
->edge_next
= seg
;
1130 /* if an edge was found, simply add the segment to the edge's list */
1131 seg
->edge_next
= found
->first
;
1132 found
->last
->edge_next
= seg
;
1137 /*****************************************************************/
1139 /* Good, we now compute each edge's properties according to */
1140 /* the segments found on its position. Basically, these are */
1142 /* - the edge's main direction */
1143 /* - stem edge, serif edge or both (which defaults to stem then) */
1144 /* - rounded edge, straight or both (which defaults to straight) */
1145 /* - link for edge */
1147 /*****************************************************************/
1149 /* first of all, set the `edge' field in each segment -- this is */
1150 /* required in order to compute edge links */
1152 /* note that removing this loop and setting the `edge' field of each */
1153 /* segment directly in the code above slows down execution speed for */
1154 /* some reasons on platforms like the Sun */
1156 TA_Edge edges
= axis
->edges
;
1157 TA_Edge edge_limit
= edges
+ axis
->num_edges
;
1161 for (edge
= edges
; edge
< edge_limit
; edge
++)
1168 seg
= seg
->edge_next
;
1169 } while (seg
!= edge
->first
);
1172 /* now compute each edge properties */
1173 for (edge
= edges
; edge
< edge_limit
; edge
++)
1175 FT_Int is_round
= 0; /* does it contain round segments? */
1176 FT_Int is_straight
= 0; /* does it contain straight segments? */
1178 FT_Pos ups
= 0; /* number of upwards segments */
1179 FT_Pos downs
= 0; /* number of downwards segments */
1190 /* check for roundness of segment */
1191 if (seg
->flags
& TA_EDGE_ROUND
)
1197 /* check for segment direction */
1198 if (seg
->dir
== up_dir
)
1199 ups
+= seg
->max_coord
- seg
->min_coord
;
1201 downs
+= seg
->max_coord
- seg
->min_coord
;
1204 /* check for links -- */
1205 /* if seg->serif is set, then seg->link must be ignored */
1206 is_serif
= (FT_Bool
)(seg
->serif
1208 && seg
->serif
->edge
!= edge
);
1210 if ((seg
->link
&& seg
->link
->edge
!= NULL
)
1223 edge2
= edge
->serif
;
1232 edge_delta
= edge
->fpos
- edge2
->fpos
;
1234 edge_delta
= -edge_delta
;
1236 seg_delta
= seg
->pos
- seg2
->pos
;
1238 seg_delta
= -seg_delta
;
1240 if (seg_delta
< edge_delta
)
1248 edge
->serif
= edge2
;
1249 edge2
->flags
|= TA_EDGE_SERIF
;
1255 seg
= seg
->edge_next
;
1256 } while (seg
!= edge
->first
);
1258 /* set the round/straight flags */
1259 edge
->flags
= TA_EDGE_NORMAL
;
1262 && is_round
>= is_straight
)
1263 edge
->flags
|= TA_EDGE_ROUND
;
1266 /* set the edge's main direction */
1267 edge
->dir
= TA_DIR_NONE
;
1270 edge
->dir
= (FT_Char
)up_dir
;
1272 else if (ups
< downs
)
1273 edge
->dir
= (FT_Char
)-up_dir
;
1275 else if (ups
== downs
)
1276 edge
->dir
= 0; /* both up and down! */
1279 /* get rid of serifs if link is set */
1280 /* XXX: this gets rid of many unpleasant artefacts! */
1281 /* example: the `c' in cour.pfa at size 13 */
1283 if (edge
->serif
&& edge
->link
)
1293 /* detect segments and edges for given dimension */
1296 ta_latin_hints_detect_features(TA_GlyphHints hints
,
1302 error
= ta_latin_hints_compute_segments(hints
, dim
);
1305 ta_latin_hints_link_segments(hints
, dim
);
1307 error
= ta_latin_hints_compute_edges(hints
, dim
);
1314 /* compute all edges which lie within blue zones */
1317 ta_latin_hints_compute_blue_edges(TA_GlyphHints hints
,
1318 TA_LatinMetrics metrics
)
1320 TA_AxisHints axis
= &hints
->axis
[TA_DIMENSION_VERT
];
1322 TA_Edge edge
= axis
->edges
;
1323 TA_Edge edge_limit
= edge
+ axis
->num_edges
;
1325 TA_LatinAxis latin
= &metrics
->axis
[TA_DIMENSION_VERT
];
1326 FT_Fixed scale
= latin
->scale
;
1329 /* compute which blue zones are active, */
1330 /* i.e. have their scaled size < 3/4 pixels */
1332 /* for each horizontal edge search the blue zone which is closest */
1333 for (; edge
< edge_limit
; edge
++)
1336 TA_Width best_blue
= NULL
;
1337 FT_Pos best_dist
; /* initial threshold */
1339 FT_UInt best_blue_idx
= 0;
1340 FT_Bool best_blue_is_shoot
= 0;
1343 /* compute the initial threshold as a fraction of the EM size */
1344 /* (the value 40 is heuristic) */
1345 best_dist
= FT_MulFix(metrics
->units_per_em
/ 40, scale
);
1347 /* assure a minimum distance of 0.5px */
1348 if (best_dist
> 64 / 2)
1351 for (bb
= 0; bb
< TA_LATIN_BLUE_MAX
; bb
++)
1353 TA_LatinBlue blue
= latin
->blues
+ bb
;
1354 FT_Bool is_top_blue
, is_major_dir
;
1357 /* skip inactive blue zones (i.e., those that are too large) */
1358 if (!(blue
->flags
& TA_LATIN_BLUE_ACTIVE
))
1361 /* if it is a top zone, check for right edges -- */
1362 /* if it is a bottom zone, check for left edges */
1363 is_top_blue
= (FT_Byte
)((blue
->flags
& TA_LATIN_BLUE_TOP
) != 0);
1364 is_major_dir
= FT_BOOL(edge
->dir
== axis
->major_dir
);
1366 /* if it is a top zone, the edge must be against the major */
1367 /* direction; if it is a bottom zone, it must be in the major */
1369 if (is_top_blue
^ is_major_dir
)
1374 /* first of all, compare it to the reference position */
1375 dist
= edge
->fpos
- blue
->ref
.org
;
1379 dist
= FT_MulFix(dist
, scale
);
1380 if (dist
< best_dist
)
1383 best_blue
= &blue
->ref
;
1386 best_blue_is_shoot
= 0;
1389 /* now compare it to the overshoot position and check whether */
1390 /* the edge is rounded, and whether the edge is over the */
1391 /* reference position of a top zone, or under the reference */
1392 /* position of a bottom zone */
1393 if (edge
->flags
& TA_EDGE_ROUND
1396 FT_Bool is_under_ref
= FT_BOOL(edge
->fpos
< blue
->ref
.org
);
1399 if (is_top_blue
^ is_under_ref
)
1401 dist
= edge
->fpos
- blue
->shoot
.org
;
1405 dist
= FT_MulFix(dist
, scale
);
1406 if (dist
< best_dist
)
1409 best_blue
= &blue
->shoot
;
1412 best_blue_is_shoot
= 1;
1421 edge
->blue_edge
= best_blue
;
1422 edge
->best_blue_idx
= best_blue_idx
;
1423 edge
->best_blue_is_shoot
= best_blue_is_shoot
;
1429 /* initalize hinting engine */
1432 ta_latin_hints_init(TA_GlyphHints hints
,
1433 TA_LatinMetrics metrics
)
1435 FT_Render_Mode mode
;
1436 FT_UInt32 scaler_flags
, other_flags
;
1437 FT_Face face
= metrics
->root
.scaler
.face
;
1440 ta_glyph_hints_rescale(hints
, (TA_ScriptMetrics
)metrics
);
1442 /* correct x_scale and y_scale if needed, since they may have */
1443 /* been modified by `ta_latin_metrics_scale_dim' above */
1444 hints
->x_scale
= metrics
->axis
[TA_DIMENSION_HORZ
].scale
;
1445 hints
->x_delta
= metrics
->axis
[TA_DIMENSION_HORZ
].delta
;
1446 hints
->y_scale
= metrics
->axis
[TA_DIMENSION_VERT
].scale
;
1447 hints
->y_delta
= metrics
->axis
[TA_DIMENSION_VERT
].delta
;
1449 /* compute flags depending on render mode, etc. */
1450 mode
= metrics
->root
.scaler
.render_mode
;
1452 #if 0 /* #ifdef TA_CONFIG_OPTION_USE_WARPER */
1453 if (mode
== FT_RENDER_MODE_LCD
1454 || mode
== FT_RENDER_MODE_LCD_V
)
1455 metrics
->root
.scaler
.render_mode
=
1456 mode
= FT_RENDER_MODE_NORMAL
;
1459 scaler_flags
= hints
->scaler_flags
;
1462 /* we snap the width of vertical stems for the monochrome */
1463 /* and horizontal LCD rendering targets only */
1464 if (mode
== FT_RENDER_MODE_MONO
1465 || mode
== FT_RENDER_MODE_LCD
)
1466 other_flags
|= TA_LATIN_HINTS_HORZ_SNAP
;
1468 /* we snap the width of horizontal stems for the monochrome */
1469 /* and vertical LCD rendering targets only */
1470 if (mode
== FT_RENDER_MODE_MONO
1471 || mode
== FT_RENDER_MODE_LCD_V
)
1472 other_flags
|= TA_LATIN_HINTS_VERT_SNAP
;
1474 /* we adjust stems to full pixels only if we don't use the `light' mode */
1475 if (mode
!= FT_RENDER_MODE_LIGHT
)
1476 other_flags
|= TA_LATIN_HINTS_STEM_ADJUST
;
1478 if (mode
== FT_RENDER_MODE_MONO
)
1479 other_flags
|= TA_LATIN_HINTS_MONO
;
1481 /* in `light' hinting mode we disable horizontal hinting completely; */
1482 /* we also do it if the face is italic */
1483 if (mode
== FT_RENDER_MODE_LIGHT
1484 || (face
->style_flags
& FT_STYLE_FLAG_ITALIC
) != 0)
1485 scaler_flags
|= TA_SCALER_FLAG_NO_HORIZONTAL
;
1487 hints
->scaler_flags
= scaler_flags
;
1488 hints
->other_flags
= other_flags
;
1494 /* snap a given width in scaled coordinates to */
1495 /* one of the current standard widths */
1498 ta_latin_snap_width(TA_Width widths
,
1503 FT_Pos best
= 64 + 32 + 2;
1504 FT_Pos reference
= width
;
1508 for (n
= 0; n
< count
; n
++)
1525 scaled
= TA_PIX_ROUND(reference
);
1527 if (width
>= reference
)
1529 if (width
< scaled
+ 48)
1534 if (width
> scaled
- 48)
1542 /* compute the snapped width of a given stem, ignoring very thin ones */
1544 /* there is a lot of voodoo in this function; changing the hard-coded */
1545 /* parameters influence the whole hinting process */
1548 ta_latin_compute_stem_width(TA_GlyphHints hints
,
1554 TA_LatinMetrics metrics
= (TA_LatinMetrics
) hints
->metrics
;
1555 TA_LatinAxis axis
= &metrics
->axis
[dim
];
1557 FT_Pos dist
= width
;
1559 FT_Int vertical
= (dim
== TA_DIMENSION_VERT
);
1562 if (!TA_LATIN_HINTS_DO_STEM_ADJUST(hints
)
1563 || axis
->extra_light
)
1572 if ((vertical
&& !TA_LATIN_HINTS_DO_VERT_SNAP(hints
))
1573 || (!vertical
&& !TA_LATIN_HINTS_DO_HORZ_SNAP(hints
)))
1575 /* smooth hinting process: very lightly quantize the stem width */
1577 /* leave the widths of serifs alone */
1578 if ((stem_flags
& TA_EDGE_SERIF
)
1582 else if (base_flags
& TA_EDGE_ROUND
)
1590 if (axis
->width_count
> 0)
1595 /* compare to standard width */
1596 delta
= dist
- axis
->widths
[0].cur
;
1603 dist
= axis
->widths
[0].cur
;
1617 else if (delta
< 32)
1619 else if (delta
< 54)
1625 dist
= (dist
+ 32) & ~63;
1630 /* strong hinting process: snap the stem width to integer pixels */
1632 FT_Pos org_dist
= dist
;
1635 dist
= ta_latin_snap_width(axis
->widths
, axis
->width_count
, dist
);
1639 /* in the case of vertical hinting, */
1640 /* always round the stem heights to integer pixels */
1643 dist
= (dist
+ 16) & ~63;
1649 if (TA_LATIN_HINTS_DO_MONO(hints
))
1651 /* monochrome horizontal hinting: */
1652 /* snap widths to integer pixels with a different threshold */
1657 dist
= (dist
+ 32) & ~63;
1661 /* for horizontal anti-aliased hinting, we adopt a more subtle */
1662 /* approach: we strengthen small stems, round stems whose size */
1663 /* is between 1 and 2 pixels to an integer, otherwise nothing */
1666 dist
= (dist
+ 64) >> 1;
1668 else if (dist
< 128)
1670 /* we only round to an integer width if the corresponding */
1671 /* distortion is less than 1/4 pixel -- otherwise, this */
1672 /* makes everything worse since the diagonals, which are */
1673 /* not hinted, appear a lot bolder or thinner than the */
1674 /* vertical stems */
1679 dist
= (dist
+ 22) & ~63;
1680 delta
= dist
- org_dist
;
1688 dist
= (dist
+ 64) >> 1;
1692 /* round otherwise to prevent color fringes in LCD mode */
1693 dist
= (dist
+ 32) & ~63;
1706 /* align one stem edge relative to the previous stem edge */
1709 ta_latin_align_linked_edge(TA_GlyphHints hints
,
1714 FT_Pos dist
= stem_edge
->opos
- base_edge
->opos
;
1716 FT_Pos fitted_width
= ta_latin_compute_stem_width(
1722 stem_edge
->pos
= base_edge
->pos
+ fitted_width
;
1724 TA_LOG((" LINK: edge %d (opos=%.2f) linked to %.2f,"
1725 " dist was %.2f, now %.2f\n",
1726 stem_edge
- hints
->axis
[dim
].edges
, stem_edge
->opos
/ 64.0,
1727 stem_edge
->pos
/ 64.0, dist
/ 64.0, fitted_width
/ 64.0));
1729 if (hints
->recorder
)
1730 hints
->recorder(ta_link
, hints
, dim
,
1731 base_edge
, stem_edge
, NULL
, NULL
, NULL
);
1735 /* shift the coordinates of the `serif' edge by the same amount */
1736 /* as the corresponding `base' edge has been moved already */
1739 ta_latin_align_serif_edge(TA_GlyphHints hints
,
1745 serif
->pos
= base
->pos
+ (serif
->opos
- base
->opos
);
1749 /* the main grid-fitting routine */
1752 ta_latin_hint_edges(TA_GlyphHints hints
,
1755 TA_AxisHints axis
= &hints
->axis
[dim
];
1757 TA_Edge edges
= axis
->edges
;
1758 TA_Edge edge_limit
= edges
+ axis
->num_edges
;
1762 TA_Edge anchor
= NULL
;
1763 FT_Int has_serifs
= 0;
1766 TA_LOG(("%s edge hinting\n", dim
== TA_DIMENSION_VERT
? "horizontal"
1769 /* we begin by aligning all stems relative to the blue zone if needed -- */
1770 /* that's only for horizontal edges */
1772 if (dim
== TA_DIMENSION_VERT
1773 && TA_HINTS_DO_BLUES(hints
))
1775 for (edge
= edges
; edge
< edge_limit
; edge
++)
1778 TA_Edge edge1
, edge2
; /* these edges form the stem to check */
1781 if (edge
->flags
& TA_EDGE_DONE
)
1784 blue
= edge
->blue_edge
;
1791 /* flip edges if the other stem is aligned to a blue zone */
1792 else if (edge2
&& edge2
->blue_edge
)
1794 blue
= edge2
->blue_edge
;
1803 TA_LOG((" BLUE_ANCHOR: edge %d (opos=%.2f) snapped to %.2f,"
1804 " was %.2f (anchor=edge %d)\n",
1805 edge1
- edges
, edge1
->opos
/ 64.0, blue
->fit
/ 64.0,
1806 edge1
->pos
/ 64.0, edge
- edges
));
1808 TA_LOG((" BLUE: edge %d (opos=%.2f) snapped to %.2f, was %.2f\n",
1809 edge1
- edges
, edge1
->opos
/ 64.0, blue
->fit
/ 64.0,
1810 edge1
->pos
/ 64.0));
1812 edge1
->pos
= blue
->fit
;
1813 edge1
->flags
|= TA_EDGE_DONE
;
1815 if (hints
->recorder
)
1818 hints
->recorder(ta_blue_anchor
, hints
, dim
,
1819 edge1
, edge
, NULL
, NULL
, NULL
);
1821 hints
->recorder(ta_blue
, hints
, dim
,
1822 edge1
, NULL
, NULL
, NULL
, NULL
);
1825 if (edge2
&& !edge2
->blue_edge
)
1827 ta_latin_align_linked_edge(hints
, dim
, edge1
, edge2
);
1828 edge2
->flags
|= TA_EDGE_DONE
;
1836 /* now we align all other stem edges, */
1837 /* trying to maintain the relative order of stems in the glyph */
1838 for (edge
= edges
; edge
< edge_limit
; edge
++)
1843 if (edge
->flags
& TA_EDGE_DONE
)
1846 /* skip all non-stem edges */
1854 /* now align the stem */
1856 /* this should not happen, but it's better to be safe */
1857 if (edge2
->blue_edge
)
1859 TA_LOG((" ASSERTION FAILED for edge %d\n", edge2
-edges
));
1861 ta_latin_align_linked_edge(hints
, dim
, edge2
, edge
);
1862 edge
->flags
|= TA_EDGE_DONE
;
1868 /* if we reach this if clause, no stem has been aligned yet */
1870 FT_Pos org_len
, org_center
, cur_len
;
1871 FT_Pos cur_pos1
, error1
, error2
, u_off
, d_off
;
1874 org_len
= edge2
->opos
- edge
->opos
;
1875 cur_len
= ta_latin_compute_stem_width(hints
, dim
, org_len
,
1876 edge
->flags
, edge2
->flags
);
1878 /* some voodoo to specially round edges for small stem widths; */
1879 /* the idea is to align the center of a stem, */
1880 /* then shifting the stem edges to suitable positions */
1889 /* 1px < width < 1.5px */
1896 org_center
= edge
->opos
+ (org_len
>> 1);
1897 cur_pos1
= TA_PIX_ROUND(org_center
);
1899 error1
= org_center
- (cur_pos1
- u_off
);
1903 error2
= org_center
- (cur_pos1
+ d_off
);
1907 if (error1
< error2
)
1912 edge
->pos
= cur_pos1
- cur_len
/ 2;
1913 edge2
->pos
= edge
->pos
+ cur_len
;
1916 edge
->pos
= TA_PIX_ROUND(edge
->opos
);
1919 edge
->flags
|= TA_EDGE_DONE
;
1921 TA_LOG((" ANCHOR: edge %d (opos=%.2f) and %d (opos=%.2f)"
1922 " snapped to %.2f and %.2f\n",
1923 edge
- edges
, edge
->opos
/ 64.0,
1924 edge2
- edges
, edge2
->opos
/ 64.0,
1925 edge
->pos
/ 64.0, edge2
->pos
/ 64.0));
1927 if (hints
->recorder
)
1928 hints
->recorder(ta_anchor
, hints
, dim
,
1929 edge
, edge2
, NULL
, NULL
, NULL
);
1931 ta_latin_align_linked_edge(hints
, dim
, edge
, edge2
);
1935 FT_Pos org_pos
, org_len
, org_center
, cur_len
;
1936 FT_Pos cur_pos1
, cur_pos2
, delta1
, delta2
;
1939 org_pos
= anchor
->pos
+ (edge
->opos
- anchor
->opos
);
1940 org_len
= edge2
->opos
- edge
->opos
;
1941 org_center
= org_pos
+ (org_len
>> 1);
1943 cur_len
= ta_latin_compute_stem_width(hints
, dim
, org_len
,
1944 edge
->flags
, edge2
->flags
);
1946 if (edge2
->flags
& TA_EDGE_DONE
)
1948 TA_LOG((" ADJUST: edge %d (pos=%.2f) moved to %.2f\n",
1949 edge
- edges
, edge
->pos
/ 64.0,
1950 (edge2
->pos
- cur_len
) / 64.0));
1952 edge
->pos
= edge2
->pos
- cur_len
;
1954 if (hints
->recorder
)
1956 TA_Edge bound
= NULL
;
1962 hints
->recorder(ta_adjust
, hints
, dim
,
1963 edge
, edge2
, NULL
, bound
, NULL
);
1967 else if (cur_len
< 96)
1969 FT_Pos u_off
, d_off
;
1972 cur_pos1
= TA_PIX_ROUND(org_center
);
1985 delta1
= org_center
- (cur_pos1
- u_off
);
1989 delta2
= org_center
- (cur_pos1
+ d_off
);
1993 if (delta1
< delta2
)
1998 edge
->pos
= cur_pos1
- cur_len
/ 2;
1999 edge2
->pos
= cur_pos1
+ cur_len
/ 2;
2001 TA_LOG((" STEM: edge %d (opos=%.2f) linked to %d (opos=%.2f)"
2002 " snapped to %.2f and %.2f\n",
2003 edge
- edges
, edge
->opos
/ 64.0,
2004 edge2
- edges
, edge2
->opos
/ 64.0,
2005 edge
->pos
/ 64.0, edge2
->pos
/ 64.0));
2007 if (hints
->recorder
)
2009 TA_Edge bound
= NULL
;
2015 hints
->recorder(ta_stem
, hints
, dim
,
2016 edge
, edge2
, NULL
, bound
, NULL
);
2022 org_pos
= anchor
->pos
+ (edge
->opos
- anchor
->opos
);
2023 org_len
= edge2
->opos
- edge
->opos
;
2024 org_center
= org_pos
+ (org_len
>> 1);
2026 cur_len
= ta_latin_compute_stem_width(hints
, dim
, org_len
,
2027 edge
->flags
, edge2
->flags
);
2029 cur_pos1
= TA_PIX_ROUND(org_pos
);
2030 delta1
= cur_pos1
+ (cur_len
>> 1) - org_center
;
2034 cur_pos2
= TA_PIX_ROUND(org_pos
+ org_len
) - cur_len
;
2035 delta2
= cur_pos2
+ (cur_len
>> 1) - org_center
;
2039 edge
->pos
= (delta1
< delta2
) ? cur_pos1
: cur_pos2
;
2040 edge2
->pos
= edge
->pos
+ cur_len
;
2042 TA_LOG((" STEM: edge %d (opos=%.2f) linked to %d (opos=%.2f)"
2043 " snapped to %.2f and %.2f\n",
2044 edge
- edges
, edge
->opos
/ 64.0,
2045 edge2
- edges
, edge2
->opos
/ 64.0,
2046 edge
->pos
/ 64.0, edge2
->pos
/ 64.0));
2048 if (hints
->recorder
)
2050 TA_Edge bound
= NULL
;
2056 hints
->recorder(ta_stem
, hints
, dim
,
2057 edge
, edge2
, NULL
, bound
, NULL
);
2061 edge
->flags
|= TA_EDGE_DONE
;
2062 edge2
->flags
|= TA_EDGE_DONE
;
2065 && edge
->pos
< edge
[-1].pos
)
2067 TA_LOG((" BOUND: edge %d (pos=%.2f) moved to %.2f\n",
2068 edge
- edges
, edge
->pos
/ 64.0, edge
[-1].pos
/ 64.0));
2070 edge
->pos
= edge
[-1].pos
;
2072 if (hints
->recorder
)
2073 hints
->recorder(ta_bound
, hints
, dim
,
2074 edge
, &edge
[-1], NULL
, NULL
, NULL
);
2079 /* make sure that lowercase m's maintain their symmetry */
2081 /* In general, lowercase m's have six vertical edges if they are sans */
2082 /* serif, or twelve if they are with serifs. This implementation is */
2083 /* based on that assumption, and seems to work very well with most */
2084 /* faces. However, if for a certain face this assumption is not */
2085 /* true, the m is just rendered like before. In addition, any stem */
2086 /* correction will only be applied to symmetrical glyphs (even if the */
2087 /* glyph is not an m), so the potential for unwanted distortion is */
2088 /* relatively low. */
2090 /* we don't handle horizontal edges since we can't easily assure that */
2091 /* the third (lowest) stem aligns with the base line; it might end up */
2092 /* one pixel higher or lower */
2094 n_edges
= edge_limit
- edges
;
2095 if (dim
== TA_DIMENSION_HORZ
2096 && (n_edges
== 6 || n_edges
== 12))
2098 TA_Edge edge1
, edge2
, edge3
;
2099 FT_Pos dist1
, dist2
, span
, delta
;
2115 dist1
= edge2
->opos
- edge1
->opos
;
2116 dist2
= edge3
->opos
- edge2
->opos
;
2118 span
= dist1
- dist2
;
2124 delta
= edge3
->pos
- (2 * edge2
->pos
- edge1
->pos
);
2125 edge3
->pos
-= delta
;
2127 edge3
->link
->pos
-= delta
;
2129 /* move the serifs along with the stem */
2132 (edges
+ 8)->pos
-= delta
;
2133 (edges
+ 11)->pos
-= delta
;
2136 edge3
->flags
|= TA_EDGE_DONE
;
2138 edge3
->link
->flags
|= TA_EDGE_DONE
;
2142 if (has_serifs
|| !anchor
)
2144 /* now hint the remaining edges (serifs and single) */
2145 /* in order to complete our processing */
2146 for (edge
= edges
; edge
< edge_limit
; edge
++)
2148 TA_Edge lower_bound
= NULL
;
2149 TA_Edge upper_bound
= NULL
;
2154 if (edge
->flags
& TA_EDGE_DONE
)
2161 delta
= edge
->serif
->opos
- edge
->opos
;
2167 lower_bound
= &edge
[-1];
2169 if (edge
+ 1 < edge_limit
2170 && edge
[1].flags
& TA_EDGE_DONE
)
2171 upper_bound
= &edge
[1];
2174 if (delta
< 64 + 16)
2176 ta_latin_align_serif_edge(hints
, edge
->serif
, edge
);
2178 TA_LOG((" SERIF: edge %d (opos=%.2f) serif to %d (opos=%.2f)"
2179 " aligned to %.2f\n",
2180 edge
- edges
, edge
->opos
/ 64.0,
2181 edge
->serif
- edges
, edge
->serif
->opos
/ 64.0,
2184 if (hints
->recorder
)
2185 hints
->recorder(ta_serif
, hints
, dim
,
2186 edge
, NULL
, NULL
, lower_bound
, upper_bound
);
2190 edge
->pos
= TA_PIX_ROUND(edge
->opos
);
2193 TA_LOG((" SERIF_ANCHOR: edge %d (opos=%.2f) snapped to %.2f\n",
2194 edge
- edges
, edge
->opos
/ 64.0, edge
->pos
/ 64.0));
2196 if (hints
->recorder
)
2197 hints
->recorder(ta_serif_anchor
, hints
, dim
,
2198 edge
, NULL
, NULL
, lower_bound
, upper_bound
);
2202 TA_Edge before
, after
;
2205 for (before
= edge
- 1; before
>= edges
; before
--)
2206 if (before
->flags
& TA_EDGE_DONE
)
2209 for (after
= edge
+ 1; after
< edge_limit
; after
++)
2210 if (after
->flags
& TA_EDGE_DONE
)
2213 if (before
>= edges
&& before
< edge
2214 && after
< edge_limit
&& after
> edge
)
2216 if (after
->opos
== before
->opos
)
2217 edge
->pos
= before
->pos
;
2219 edge
->pos
= before
->pos
+ FT_MulDiv(edge
->opos
- before
->opos
,
2220 after
->pos
- before
->pos
,
2221 after
->opos
- before
->opos
);
2223 TA_LOG((" SERIF_LINK1: edge %d (opos=%.2f) snapped to %.2f"
2224 " from %d (opos=%.2f)\n",
2225 edge
- edges
, edge
->opos
/ 64.0,
2227 before
- edges
, before
->opos
/ 64.0));
2229 if (hints
->recorder
)
2230 hints
->recorder(ta_serif_link1
, hints
, dim
,
2231 edge
, before
, after
, lower_bound
, upper_bound
);
2235 edge
->pos
= anchor
->pos
+ ((edge
->opos
- anchor
->opos
+ 16) & ~31);
2237 TA_LOG((" SERIF_LINK2: edge %d (opos=%.2f) snapped to %.2f\n",
2238 edge
- edges
, edge
->opos
/ 64.0, edge
->pos
/ 64.0));
2240 if (hints
->recorder
)
2241 hints
->recorder(ta_serif_link2
, hints
, dim
,
2242 edge
, NULL
, NULL
, lower_bound
, upper_bound
);
2246 edge
->flags
|= TA_EDGE_DONE
;
2249 && edge
->pos
< edge
[-1].pos
)
2251 TA_LOG((" BOUND: edge %d (pos=%.2f) moved to %.2f\n",
2252 edge
- edges
, edge
->pos
/ 64.0, edge
[-1].pos
/ 64.0));
2254 edge
->pos
= edge
[-1].pos
;
2256 if (hints
->recorder
)
2257 hints
->recorder(ta_bound
, hints
, dim
,
2258 edge
, &edge
[-1], NULL
, NULL
, NULL
);
2261 if (edge
+ 1 < edge_limit
2262 && edge
[1].flags
& TA_EDGE_DONE
2263 && edge
->pos
> edge
[1].pos
)
2265 TA_LOG((" BOUND: edge %d (pos=%.2f) moved to %.2f\n",
2266 edge
- edges
, edge
->pos
/ 64.0, edge
[1].pos
/ 64.0));
2268 edge
->pos
= edge
[1].pos
;
2270 if (hints
->recorder
)
2271 hints
->recorder(ta_bound
, hints
, dim
,
2272 edge
, &edge
[1], NULL
, NULL
, NULL
);
2281 /* apply the complete hinting algorithm to a latin glyph */
2284 ta_latin_hints_apply(TA_GlyphHints hints
,
2285 FT_Outline
* outline
,
2286 TA_LatinMetrics metrics
)
2292 error
= ta_glyph_hints_reload(hints
, outline
);
2296 /* analyze glyph outline */
2297 #ifdef TA_CONFIG_OPTION_USE_WARPER
2298 if (metrics
->root
.scaler
.render_mode
== FT_RENDER_MODE_LIGHT
2299 || TA_HINTS_DO_HORIZONTAL(hints
))
2301 if (TA_HINTS_DO_HORIZONTAL(hints
))
2304 error
= ta_latin_hints_detect_features(hints
, TA_DIMENSION_HORZ
);
2309 if (TA_HINTS_DO_VERTICAL(hints
))
2311 error
= ta_latin_hints_detect_features(hints
, TA_DIMENSION_VERT
);
2315 ta_latin_hints_compute_blue_edges(hints
, metrics
);
2318 /* grid-fit the outline */
2319 for (dim
= 0; dim
< TA_DIMENSION_MAX
; dim
++)
2321 #ifdef TA_CONFIG_OPTION_USE_WARPER
2322 if (dim
== TA_DIMENSION_HORZ
2323 && metrics
->root
.scaler
.render_mode
== FT_RENDER_MODE_LIGHT
)
2325 TA_WarperRec warper
;
2330 ta_warper_compute(&warper
, hints
, (TA_Dimension
)dim
, &scale
, &delta
);
2331 ta_glyph_hints_scale_dim(hints
, (TA_Dimension
)dim
, scale
, delta
);
2337 if ((dim
== TA_DIMENSION_HORZ
&& TA_HINTS_DO_HORIZONTAL(hints
))
2338 || (dim
== TA_DIMENSION_VERT
&& TA_HINTS_DO_VERTICAL(hints
)))
2340 ta_latin_hint_edges(hints
, (TA_Dimension
)dim
);
2341 ta_glyph_hints_align_edge_points(hints
, (TA_Dimension
)dim
);
2342 ta_glyph_hints_align_strong_points(hints
, (TA_Dimension
)dim
);
2343 ta_glyph_hints_align_weak_points(hints
, (TA_Dimension
)dim
);
2346 ta_glyph_hints_save(hints
, outline
);
2353 /* XXX: this should probably fine tuned to differentiate better between */
2356 static const TA_Script_UniRangeRec ta_latin_uniranges
[] =
2358 TA_UNIRANGE_REC(0x0020UL
, 0x007FUL
), /* Basic Latin (no control chars) */
2359 TA_UNIRANGE_REC(0x00A0UL
, 0x00FFUL
), /* Latin-1 Supplement (no control chars) */
2360 TA_UNIRANGE_REC(0x0100UL
, 0x017FUL
), /* Latin Extended-A */
2361 TA_UNIRANGE_REC(0x0180UL
, 0x024FUL
), /* Latin Extended-B */
2362 TA_UNIRANGE_REC(0x0250UL
, 0x02AFUL
), /* IPA Extensions */
2363 TA_UNIRANGE_REC(0x02B0UL
, 0x02FFUL
), /* Spacing Modifier Letters */
2364 TA_UNIRANGE_REC(0x0300UL
, 0x036FUL
), /* Combining Diacritical Marks */
2365 TA_UNIRANGE_REC(0x0370UL
, 0x03FFUL
), /* Greek and Coptic */
2366 TA_UNIRANGE_REC(0x0400UL
, 0x04FFUL
), /* Cyrillic */
2367 TA_UNIRANGE_REC(0x0500UL
, 0x052FUL
), /* Cyrillic Supplement */
2368 TA_UNIRANGE_REC(0x1D00UL
, 0x1D7FUL
), /* Phonetic Extensions */
2369 TA_UNIRANGE_REC(0x1D80UL
, 0x1DBFUL
), /* Phonetic Extensions Supplement */
2370 TA_UNIRANGE_REC(0x1DC0UL
, 0x1DFFUL
), /* Combining Diacritical Marks Supplement */
2371 TA_UNIRANGE_REC(0x1E00UL
, 0x1EFFUL
), /* Latin Extended Additional */
2372 TA_UNIRANGE_REC(0x1F00UL
, 0x1FFFUL
), /* Greek Extended */
2373 TA_UNIRANGE_REC(0x2000UL
, 0x206FUL
), /* General Punctuation */
2374 TA_UNIRANGE_REC(0x2070UL
, 0x209FUL
), /* Superscripts and Subscripts */
2375 TA_UNIRANGE_REC(0x20A0UL
, 0x20CFUL
), /* Currency Symbols */
2376 TA_UNIRANGE_REC(0x2150UL
, 0x218FUL
), /* Number Forms */
2377 TA_UNIRANGE_REC(0x2460UL
, 0x24FFUL
), /* Enclosed Alphanumerics */
2378 TA_UNIRANGE_REC(0x2C60UL
, 0x2C7FUL
), /* Latin Extended-C */
2379 TA_UNIRANGE_REC(0x2DE0UL
, 0x2DFFUL
), /* Cyrillic Extended-A */
2380 TA_UNIRANGE_REC(0xA640UL
, 0xA69FUL
), /* Cyrillic Extended-B */
2381 TA_UNIRANGE_REC(0xA720UL
, 0xA7FFUL
), /* Latin Extended-D */
2382 TA_UNIRANGE_REC(0xFB00UL
, 0xFB06UL
), /* Alphab. Present. Forms (Latin Ligs) */
2383 TA_UNIRANGE_REC(0x1D400UL
, 0x1D7FFUL
), /* Mathematical Alphanumeric Symbols */
2384 TA_UNIRANGE_REC(0UL, 0UL)
2388 const TA_ScriptClassRec ta_latin_script_class
=
2393 sizeof (TA_LatinMetricsRec
),
2395 (TA_Script_InitMetricsFunc
)ta_latin_metrics_init
,
2396 (TA_Script_ScaleMetricsFunc
)ta_latin_metrics_scale
,
2397 (TA_Script_DoneMetricsFunc
)NULL
,
2399 (TA_Script_InitHintsFunc
)ta_latin_hints_init
,
2400 (TA_Script_ApplyHintsFunc
)ta_latin_hints_apply
2403 /* end of talatin.c */