static void
af_cjk_hints_link_segments( AF_GlyphHints hints,
AF_Dimension dim )
{
AF_AxisHints axis = &hints->axis[dim];
AF_Segment segments = axis->segments;
AF_Segment segment_limit = segments + axis->num_segments;
AF_Direction major_dir = axis->major_dir;
AF_Segment seg1, seg2;
FT_Pos len_threshold;
FT_Pos dist_threshold;
len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 );
dist_threshold = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
: hints->y_scale;
dist_threshold = FT_DivFix( 64 * 3, dist_threshold );
/* now compare each segment to the others */
for ( seg1 = segments; seg1 < segment_limit; seg1++ )
{
/* the fake segments are for metrics hinting only */
if ( seg1->first == seg1->last )
continue;
if ( seg1->dir != major_dir )
continue;
for ( seg2 = segments; seg2 < segment_limit; seg2++ )
if ( seg2 != seg1 && seg1->dir + seg2->dir == 0 )
{
FT_Pos dist = seg2->pos - seg1->pos;
if ( dist < 0 )
continue;
{
FT_Pos min = seg1->min_coord;
FT_Pos max = seg1->max_coord;
FT_Pos len;
if ( min < seg2->min_coord )
min = seg2->min_coord;
if ( max > seg2->max_coord )
max = seg2->max_coord;
len = max - min;
if ( len >= len_threshold )
{
if ( dist * 8 < seg1->score * 9 &&
( dist * 8 < seg1->score * 7 || seg1->len < len ) )
{
seg1->score = dist;
seg1->len = len;
seg1->link = seg2;
}
if ( dist * 8 < seg2->score * 9 &&
( dist * 8 < seg2->score * 7 || seg2->len < len ) )
{
seg2->score = dist;
seg2->len = len;
seg2->link = seg1;
}
}
}
}
}
/*
* now compute the `serif' segments
*
* In Hanzi, some strokes are wider on one or both of the ends.
* We either identify the stems on the ends as serifs or remove
* the linkage, depending on the length of the stems.
*
*/
{
AF_Segment link1, link2;
for ( seg1 = segments; seg1 < segment_limit; seg1++ )
{
link1 = seg1->link;
if ( !link1 || link1->link != seg1 || link1->pos <= seg1->pos )
continue;
if ( seg1->score >= dist_threshold )
continue;
for ( seg2 = segments; seg2 < segment_limit; seg2++ )
{
if ( seg2->pos > seg1->pos || seg1 == seg2 )
continue;
link2 = seg2->link;
if ( !link2 || link2->link != seg2 || link2->pos < link1->pos )
continue;
if ( seg1->pos == seg2->pos && link1->pos == link2->pos )
continue;
if ( seg2->score <= seg1->score || seg1->score * 4 <= seg2->score )
continue;
/* seg2 < seg1 < link1 < link2 */
if ( seg1->len >= seg2->len * 3 )
{
AF_Segment seg;
for ( seg = segments; seg < segment_limit; seg++ )
{
AF_Segment link = seg->link;
if ( link == seg2 )
{
seg->link = 0;
seg->serif = link1;
}
else if ( link == link2 )
{
seg->link = 0;
seg->serif = seg1;
}
}
}
else
{
seg1->link = link1->link = 0;
break;
}
}
}
}
for ( seg1 = segments; seg1 < segment_limit; seg1++ )
{
seg2 = seg1->link;
if ( seg2 )
{
seg2->num_linked++;
if ( seg2->link != seg1 )
{
seg1->link = 0;
if ( seg2->score < dist_threshold || seg1->score < seg2->score * 4 )
seg1->serif = seg2->link;
else
seg2->num_linked--;
}
}
}
}
af_latin_metrics_init_widths( AF_LatinMetrics metrics,
FT_Face face,
FT_ULong charcode )
{
/* scan the array of segments in each direction */
AF_GlyphHintsRec hints[1];
af_glyph_hints_init( hints, face->memory );
metrics->axis[AF_DIMENSION_HORZ].width_count = 0;
metrics->axis[AF_DIMENSION_VERT].width_count = 0;
{
FT_Error error;
FT_UInt glyph_index;
int dim;
AF_LatinMetricsRec dummy[1];
AF_Scaler scaler = &dummy->root.scaler;
glyph_index = FT_Get_Char_Index( face, charcode );
if ( glyph_index == 0 )
goto Exit;
error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
if ( error || face->glyph->outline.n_points <= 0 )
goto Exit;
FT_ZERO( dummy );
dummy->units_per_em = metrics->units_per_em;
scaler->x_scale = scaler->y_scale = 0x10000L;
scaler->x_delta = scaler->y_delta = 0;
scaler->face = face;
scaler->render_mode = FT_RENDER_MODE_NORMAL;
scaler->flags = 0;
af_glyph_hints_rescale( hints, (AF_ScriptMetrics)dummy );
error = af_glyph_hints_reload( hints, &face->glyph->outline, 0 );
if ( error )
goto Exit;
for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
{
AF_LatinAxis axis = &metrics->axis[dim];
AF_AxisHints axhints = &hints->axis[dim];
AF_Segment seg, limit, link;
FT_UInt num_widths = 0;
error = af_latin_hints_compute_segments( hints,
(AF_Dimension)dim );
if ( error )
goto Exit;
af_latin_hints_link_segments( hints,
(AF_Dimension)dim );
seg = axhints->segments;
limit = seg + axhints->num_segments;
for ( ; seg < limit; seg++ )
{
link = seg->link;
/* we only consider stem segments there! */
if ( link && link->link == seg && link > seg )
{
FT_Pos dist;
dist = seg->pos - link->pos;
if ( dist < 0 )
dist = -dist;
if ( num_widths < AF_LATIN_MAX_WIDTHS )
axis->widths[ num_widths++ ].org = dist;
}
}
af_sort_widths( num_widths, axis->widths );
axis->width_count = num_widths;
}
Exit:
for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
{
AF_LatinAxis axis = &metrics->axis[dim];
FT_Pos stdw;
stdw = ( axis->width_count > 0 )
? axis->widths[0].org
: AF_LATIN_CONSTANT( metrics, 50 );
/* let's try 20% of the smallest width */
axis->edge_distance_threshold = stdw / 5;
axis->standard_width = stdw;
axis->extra_light = 0;
}
}
af_glyph_hints_done( hints );
}