ref: d1d4bffe2f0171481693d17fe3ebad3e82e5d911
dir: /src/autofit/afcjk.c/
/***************************************************************************/
/* */
/* afcjk.c */
/* */
/* Auto-fitter hinting routines for CJK script (body). */
/* */
/* Copyright 2006 by */
/* David Turner, Robert Wilhelm, and Werner Lemberg. */
/* */
/* This file is part of the FreeType project, and may only be used, */
/* modified, and distributed under the terms of the FreeType project */
/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
/* this file you indicate that you have read the license and */
/* understand and accept it fully. */
/* */
/***************************************************************************/
/*
* The algorithm is based on akito's autohint patch, available here:
*
* http://www.kde.gr.jp/~akito/patch/freetype2/
*
*/
#define xxAF_MOD_CJK
#ifdef AF_MOD_CJK
#include "afcjk.h"
#include "aferrors.h"
#ifdef AF_USE_WARPER
#include "afwarp.h"
#endif
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** C J K G L O B A L M E T R I C S *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
static FT_Error
af_cjk_metrics_init( AF_LatinMetrics metrics,
FT_Face face )
{
FT_CharMap oldmap = face->charmap;
metrics->units_per_em = face->units_per_EM;
/* TODO are there blues? */
if ( FT_Select_Charmap( face, FT_ENCODING_UNICODE ) )
{
FT_Pos threshold = 50 * metrics->units_per_em / 2048;
metrics->axis[0].edge_distance_threshold = threshold / 5;
metrics->axis[1].edge_distance_threshold = threshold / 5;
}
else
af_latin_metrics_init_widths( metrics, face, 0x7530 );
FT_Set_Charmap( face, oldmap );
return AF_Err_Ok;
}
static void
af_cjk_metrics_scale_dim( AF_LatinMetrics metrics,
AF_Scaler scaler,
AF_Dimension dim )
{
AF_LatinAxis axis;
axis = &metrics->axis[dim];
if ( dim == AF_DIMENSION_HORZ )
{
axis->scale = scaler->x_scale;
axis->delta = scaler->x_delta;
}
else
{
axis->scale = scaler->y_scale;
axis->delta = scaler->y_delta;
}
}
static void
af_cjk_metrics_scale( AF_LatinMetrics metrics,
AF_Scaler scaler )
{
metrics->root.scaler = *scaler;
af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ );
af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT );
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** C J K G L Y P H A N A L Y S I S *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
static FT_Error
af_cjk_hints_compute_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;
FT_Error error;
AF_Segment seg;
error = af_latin_hints_compute_segments( hints, dim );
if ( error )
return error;
/* a segment is round if it doesn't have successive */
/* on-curve points. */
for ( seg = segments; seg < segment_limit; seg++ )
{
AF_Point pt = seg->first;
AF_Point last = seg->last;
AF_Flags f0 = pt->flags & AF_FLAG_CONTROL;
AF_Flags f1;
seg->flags &= ~AF_EDGE_ROUND;
for ( ; pt != last; f0 = f1 )
{
pt = pt->next;
f1 = pt->flags & AF_FLAG_CONTROL;
if ( !f0 && !f1 )
break;
if ( pt == last )
seg->flags |= AF_EDGE_ROUND;
}
}
return AF_Err_Ok;
}
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_UShort len_threshold;
FT_Pos dist_threshold;
len_threshold = ( (AF_LatinMetrics)hints->metrics )->units_per_em;
len_threshold = ( len_threshold * 8 ) / 2048;
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--;
}
}
}
}
static FT_Error
af_cjk_hints_compute_edges( AF_GlyphHints hints,
AF_Dimension dim )
{
AF_AxisHints axis = &hints->axis[dim];
FT_Error error = AF_Err_Ok;
FT_Memory memory = hints->memory;
AF_LatinAxis laxis = &((AF_LatinMetrics)hints->metrics)->axis[dim];
AF_Segment segments = axis->segments;
AF_Segment segment_limit = segments + axis->num_segments;
AF_Segment seg;
AF_Direction up_dir;
FT_Fixed scale;
FT_Pos edge_distance_threshold;
axis->num_edges = 0;
scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
: hints->y_scale;
up_dir = ( dim == AF_DIMENSION_HORZ ) ? AF_DIR_UP
: AF_DIR_RIGHT;
/*********************************************************************/
/* */
/* We begin by generating a sorted table of edges for the current */
/* direction. To do so, we simply scan each segment and try to find */
/* an edge in our table that corresponds to its position. */
/* */
/* If no edge is found, we create and insert a new edge in the */
/* sorted table. Otherwise, we simply add the segment to the edge's */
/* list which is then processed in the second step to compute the */
/* edge's properties. */
/* */
/* Note that the edges table is sorted along the segment/edge */
/* position. */
/* */
/*********************************************************************/
edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold,
scale );
if ( edge_distance_threshold > 64 / 4 )
{
edge_distance_threshold = 64 / 4;
edge_distance_threshold = FT_DivFix( edge_distance_threshold,
scale );
}
else
edge_distance_threshold = laxis->edge_distance_threshold;
for ( seg = segments; seg < segment_limit; seg++ )
{
AF_Edge found = 0;
FT_Pos best = 0xFFFFU;
FT_Int ee;
/* look for an edge corresponding to the segment */
for ( ee = 0; ee < axis->num_edges; ee++ )
{
AF_Edge edge = axis->edges + ee;
FT_Pos dist;
if ( edge->dir != seg->dir )
continue;
dist = seg->pos - edge->fpos;
if ( dist < 0 )
dist = -dist;
if ( dist < edge_distance_threshold && dist < best )
{
AF_Segment link = seg->link;
/* check whether all linked segments of the candidate edge */
/* can make a single edge. */
if ( link )
{
AF_Segment seg1 = edge->first;
AF_Segment link1;
FT_Pos dist2 = 0;
do
{
link1 = seg1->link;
if ( link1 )
{
dist2 = AF_SEGMENT_DIST( link, link1 );
if ( dist2 >= edge_distance_threshold )
break;
}
} while ( ( seg1 = seg1->edge_next ) != edge->first );
if ( dist2 >= edge_distance_threshold )
continue;
}
best = dist;
found = edge;
}
}
if ( !found )
{
AF_Edge edge;
/* insert a new edge in the list and */
/* sort according to the position */
error = af_axis_hints_new_edge( axis, seg->pos, memory, &edge );
if ( error )
goto Exit;
/* add the segment to the new edge's list */
FT_ZERO( edge );
edge->first = seg;
edge->last = seg;
edge->fpos = seg->pos;
edge->opos = edge->pos = FT_MulFix( seg->pos, scale );
seg->edge_next = seg;
edge->dir = seg->dir;
}
else
{
/* if an edge was found, simply add the segment to the edge's */
/* list */
seg->edge_next = found->first;
found->last->edge_next = seg;
found->last = seg;
}
}
/*********************************************************************/
/* */
/* Good, we now compute each edge's properties according to segments */
/* found on its position. Basically, these are as follows. */
/* */
/* - edge's main direction */
/* - stem edge, serif edge or both (which defaults to stem then) */
/* - rounded edge, straight or both (which defaults to straight) */
/* - link for edge */
/* */
/*********************************************************************/
/* first of all, set the `edge' field in each segment -- this is */
/* required in order to compute edge links */
/* */
/* Note that removing this loop and setting the `edge' field of each */
/* segment directly in the code above slows down execution speed for */
/* some reasons on platforms like the Sun. */
{
AF_Edge edges = axis->edges;
AF_Edge edge_limit = edges + axis->num_edges;
AF_Edge edge;
for ( edge = edges; edge < edge_limit; edge++ )
{
seg = edge->first;
if ( seg )
do
{
seg->edge = edge;
seg = seg->edge_next;
} while ( seg != edge->first );
}
/* now compute each edge properties */
for ( edge = edges; edge < edge_limit; edge++ )
{
FT_Int is_round = 0; /* does it contain round segments? */
FT_Int is_straight = 0; /* does it contain straight segments? */
seg = edge->first;
do
{
FT_Bool is_serif;
/* check for roundness of segment */
if ( seg->flags & AF_EDGE_ROUND )
is_round++;
else
is_straight++;
/* check for links -- if seg->serif is set, then seg->link must */
/* be ignored */
is_serif = (FT_Bool)( seg->serif && seg->serif->edge != edge );
if ( seg->link || is_serif )
{
AF_Edge edge2;
AF_Segment seg2;
edge2 = edge->link;
seg2 = seg->link;
if ( is_serif )
{
seg2 = seg->serif;
edge2 = edge->serif;
}
if ( edge2 )
{
FT_Pos edge_delta;
FT_Pos seg_delta;
edge_delta = edge->fpos - edge2->fpos;
if ( edge_delta < 0 )
edge_delta = -edge_delta;
seg_delta = AF_SEGMENT_DIST( seg, seg2 );
if ( seg_delta < edge_delta )
edge2 = seg2->edge;
}
else
edge2 = seg2->edge;
if ( is_serif )
{
edge->serif = edge2;
edge2->flags |= AF_EDGE_SERIF;
}
else
edge->link = edge2;
}
seg = seg->edge_next;
} while ( seg != edge->first );
/* set the round/straight flags */
edge->flags = AF_EDGE_NORMAL;
if ( is_round > 0 && is_round >= is_straight )
edge->flags |= AF_EDGE_ROUND;
/* get rid of serifs if link is set */
/* XXX: This gets rid of many unpleasant artefacts! */
/* Example: the `c' in cour.pfa at size 13 */
if ( edge->serif && edge->link )
edge->serif = 0;
}
}
Exit:
return error;
}
static FT_Error
af_cjk_hints_detect_features( AF_GlyphHints hints,
AF_Dimension dim )
{
FT_Error error;
error = af_cjk_hints_compute_segments( hints, dim );
if ( !error )
{
af_cjk_hints_link_segments( hints, dim );
error = af_cjk_hints_compute_edges( hints, dim );
}
return error;
}
static FT_Error
af_cjk_hints_init( AF_GlyphHints hints,
AF_LatinMetrics metrics )
{
FT_Render_Mode mode;
FT_UInt32 scaler_flags, other_flags;
af_glyph_hints_rescale( hints, (AF_ScriptMetrics)metrics );
/*
* correct x_scale and y_scale when needed, since they may have
* been modified af_cjk_scale_dim above
*/
hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale;
hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta;
hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale;
hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta;
/* compute flags depending on render mode, etc. */
mode = metrics->root.scaler.render_mode;
#ifdef AF_USE_WARPER
if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V )
metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL;
#endif
scaler_flags = hints->scaler_flags;
other_flags = 0;
/*
* We snap the width of vertical stems for the monochrome and
* horizontal LCD rendering targets only.
*/
if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD )
other_flags |= AF_LATIN_HINTS_HORZ_SNAP;
/*
* We snap the width of horizontal stems for the monochrome and
* vertical LCD rendering targets only.
*/
if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V )
other_flags |= AF_LATIN_HINTS_VERT_SNAP;
/*
* We adjust stems to full pixels only if we don't use the `light' mode.
*/
if ( mode != FT_RENDER_MODE_LIGHT )
other_flags |= AF_LATIN_HINTS_STEM_ADJUST;
if ( mode == FT_RENDER_MODE_MONO )
other_flags |= AF_LATIN_HINTS_MONO;
scaler_flags |= AF_SCALER_FLAG_NO_ADVANCE;
hints->scaler_flags = scaler_flags;
hints->other_flags = other_flags;
return 0;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** C J K G L Y P H G R I D - F I T T I N G *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* snap a given width in scaled coordinates to one of the */
/* current standard widths */
static FT_Pos
af_cjk_snap_width( AF_Width widths,
FT_Int count,
FT_Pos width )
{
int n;
FT_Pos best = 64 + 32 + 2;
FT_Pos reference = width;
FT_Pos scaled;
for ( n = 0; n < count; n++ )
{
FT_Pos w;
FT_Pos dist;
w = widths[n].cur;
dist = width - w;
if ( dist < 0 )
dist = -dist;
if ( dist < best )
{
best = dist;
reference = w;
}
}
scaled = FT_PIX_ROUND( reference );
if ( width >= reference )
{
if ( width < scaled + 48 )
width = reference;
}
else
{
if ( width > scaled - 48 )
width = reference;
}
return width;
}
/* compute the snapped width of a given stem */
static FT_Pos
af_cjk_compute_stem_width( AF_GlyphHints hints,
AF_Dimension dim,
FT_Pos width,
AF_Edge_Flags base_flags,
AF_Edge_Flags stem_flags )
{
AF_LatinMetrics metrics = (AF_LatinMetrics) hints->metrics;
AF_LatinAxis axis = & metrics->axis[dim];
FT_Pos dist = width;
FT_Int sign = 0;
FT_Int vertical = ( dim == AF_DIMENSION_VERT );
FT_UNUSED( base_flags );
FT_UNUSED( stem_flags );
if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
return width;
if ( dist < 0 )
{
dist = -width;
sign = 1;
}
if ( ( vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) ||
( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) )
{
/* smooth hinting process: very lightly quantize the stem width */
if ( axis->width_count > 0 )
{
if ( FT_ABS( dist - axis->widths[0].cur ) < 40 )
{
dist = axis->widths[0].cur;
if ( dist < 48 )
dist = 48;
goto Done_Width;
}
}
if ( dist < 54 )
dist += ( 54 - dist ) / 2 ;
else if ( dist < 3 * 64 )
{
FT_Pos delta;
delta = dist & 63;
dist &= -64;
if ( delta < 10 )
dist += delta;
else if ( delta < 22 )
dist += 10;
else if ( delta < 42 )
dist += delta;
else if ( delta < 54 )
dist += 54;
else
dist += delta;
}
}
else
{
/* strong hinting process: snap the stem width to integer pixels */
dist = af_cjk_snap_width( axis->widths, axis->width_count, dist );
if ( vertical )
{
/* in the case of vertical hinting, always round */
/* the stem heights to integer pixels */
if ( dist >= 64 )
dist = ( dist + 16 ) & ~63;
else
dist = 64;
}
else
{
if ( AF_LATIN_HINTS_DO_MONO( hints ) )
{
/* monochrome horizontal hinting: snap widths to integer pixels */
/* with a different threshold */
if ( dist < 64 )
dist = 64;
else
dist = ( dist + 32 ) & ~63;
}
else
{
/* for horizontal anti-aliased hinting, we adopt a more subtle */
/* approach: we strengthen small stems, round stems whose size */
/* is between 1 and 2 pixels to an integer, otherwise nothing */
if ( dist < 48 )
dist = ( dist + 64 ) >> 1;
else if ( dist < 128 )
dist = ( dist + 22 ) & ~63;
else
/* round otherwise to prevent color fringes in LCD mode */
dist = ( dist + 32 ) & ~63;
}
}
}
Done_Width:
if ( sign )
dist = -dist;
return dist;
}
/* align one stem edge relative to the previous stem edge */
static void
af_cjk_align_linked_edge( AF_GlyphHints hints,
AF_Dimension dim,
AF_Edge base_edge,
AF_Edge stem_edge )
{
FT_Pos dist = stem_edge->opos - base_edge->opos;
FT_Pos fitted_width = af_cjk_compute_stem_width(
hints, dim, dist,
(AF_Edge_Flags)base_edge->flags,
(AF_Edge_Flags)stem_edge->flags );
stem_edge->pos = base_edge->pos + fitted_width;
}
static void
af_cjk_align_serif_edge( AF_GlyphHints hints,
AF_Edge base,
AF_Edge serif )
{
FT_UNUSED( hints );
serif->pos = base->pos + ( serif->opos - base->opos );
}
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/**** ****/
/**** E D G E H I N T I N G ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
#define AF_LIGHT_MODE_MAX_HORZ_GAP 9
#define AF_LIGHT_MODE_MAX_VERT_GAP 15
#define AF_LIGHT_MODE_MAX_DELTA_ABS 14
static FT_Pos
af_hint_normal_stem( AF_GlyphHints hints,
AF_Edge edge,
AF_Edge edge2,
FT_Pos anchor,
AF_Dimension dim )
{
FT_Pos org_len, cur_len, org_center;
FT_Pos cur_pos1, cur_pos2;
FT_Pos d_off1, u_off1, d_off2, u_off2, delta;
FT_Pos offset;
FT_Pos threshold = 64;
if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
{
if ( ( edge->flags & AF_EDGE_ROUND ) &&
( edge2->flags & AF_EDGE_ROUND ) )
{
if ( dim == AF_DIMENSION_VERT )
threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP;
else
threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP;
}
else
{
if ( dim == AF_DIMENSION_VERT )
threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP / 3;
else
threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP / 3;
}
}
org_len = edge2->opos - edge->opos;
cur_len = af_cjk_compute_stem_width( hints, dim, org_len,
edge->flags, edge2->flags );
org_center = ( edge->opos + edge2->opos ) / 2 + anchor;
cur_pos1 = org_center - cur_len / 2;
cur_pos2 = cur_pos1 + cur_len;
d_off1 = cur_pos1 - FT_PIX_FLOOR( cur_pos1 );
d_off2 = cur_pos2 - FT_PIX_FLOOR( cur_pos2 );
u_off1 = 64 - d_off1;
u_off2 = 64 - d_off2;
delta = 0;
if ( d_off1 == 0 || d_off2 == 0 )
goto Exit;
if ( cur_len <= threshold )
{
if ( d_off2 < cur_len )
{
if ( u_off1 <= d_off2 )
delta = u_off1;
else
delta = -d_off2;
}
goto Exit;
}
if ( threshold < 64 )
{
if ( d_off1 >= threshold || u_off1 >= threshold ||
d_off2 >= threshold || u_off2 >= threshold )
goto Exit;
}
offset = cur_len % 64;
if ( offset < 32 )
{
if ( u_off1 <= offset || d_off2 <= offset )
goto Exit;
}
else
offset = 64 - threshold;
d_off1 = threshold - u_off1;
u_off1 = u_off1 - offset;
u_off2 = threshold - d_off2;
d_off2 = d_off2 - offset;
if ( d_off1 <= u_off1 )
u_off1 = -d_off1;
if ( d_off2 <= u_off2 )
u_off2 = -d_off2;
if ( FT_ABS( u_off1 ) <= FT_ABS( u_off2 ) )
delta = u_off1;
else
delta = u_off2;
Exit:
#if 1
if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
{
if ( delta > AF_LIGHT_MODE_MAX_DELTA_ABS )
delta = AF_LIGHT_MODE_MAX_DELTA_ABS;
else if ( delta < -AF_LIGHT_MODE_MAX_DELTA_ABS )
delta = -AF_LIGHT_MODE_MAX_DELTA_ABS;
}
#endif
cur_pos1 += delta;
if ( edge->opos < edge2->opos )
{
edge->pos = cur_pos1;
edge2->pos = cur_pos1 + cur_len;
}
else
{
edge->pos = cur_pos1 + cur_len;
edge2->pos = cur_pos1;
}
return delta;
}
static void
af_cjk_hint_edges( AF_GlyphHints hints,
AF_Dimension dim )
{
AF_AxisHints axis = &hints->axis[dim];
AF_Edge edges = axis->edges;
AF_Edge edge_limit = edges + axis->num_edges;
FT_Int n_edges;
AF_Edge edge;
AF_Edge anchor = 0;
FT_Pos delta = 0;
FT_Int skipped = 0;
/* now we align all stem edges. */
for ( edge = edges; edge < edge_limit; edge++ )
{
AF_Edge edge2;
if ( edge->flags & AF_EDGE_DONE )
continue;
/* skip all non-stem edges */
edge2 = edge->link;
if ( !edge2 )
{
skipped++;
continue;
}
/* now align the stem */
if ( edge2 < edge )
{
af_cjk_align_linked_edge( hints, dim, edge2, edge );
edge->flags |= AF_EDGE_DONE;
continue;
}
if ( dim != AF_DIMENSION_VERT && !anchor )
{
#if 0
if ( fixedpitch )
{
AF_Edge left = edge;
AF_Edge right = edge_limit - 1;
AF_EdgeRec left1, left2, right1, right2;
FT_Pos target, center1, center2;
FT_Pos delta1, delta2, d1, d2;
while ( right > left && !right->link )
right--;
left1 = *left;
left2 = *left->link;
right1 = *right->link;
right2 = *right;
delta = ( ( ( hinter->pp2.x + 32 ) & -64 ) - hinter->pp2.x ) / 2;
target = left->opos + ( right->opos - left->opos ) / 2 + delta - 16;
delta1 = delta;
delta1 += af_hint_normal_stem( hints, left, left->link,
delta1, 0 );
if ( left->link != right )
af_hint_normal_stem( hints, right->link, right, delta1, 0 );
center1 = left->pos + ( right->pos - left->pos ) / 2;
if ( center1 >= target )
delta2 = delta - 32;
else
delta2 = delta + 32;
delta2 += af_hint_normal_stem( hints, &left1, &left2, delta2, 0 );
if ( delta1 != delta2 )
{
if ( left->link != right )
af_hint_normal_stem( hints, &right1, &right2, delta2, 0 );
center2 = left1.pos + ( right2.pos - left1.pos ) / 2;
d1 = center1 - target;
d2 = center2 - target;
if ( FT_ABS( d2 ) < FT_ABS( d1 ) )
{
left->pos = left1.pos;
left->link->pos = left2.pos;
if ( left->link != right )
{
right->link->pos = right1.pos;
right->pos = right2.pos;
}
delta1 = delta2;
}
}
delta = delta1;
right->link->flags |= AF_EDGE_DONE;
right->flags |= AF_EDGE_DONE;
}
else
#endif /* 0 */
delta = af_hint_normal_stem( hints, edge, edge2, 0, 0 );
}
else
af_hint_normal_stem( hints, edge, edge2, delta, dim );
#if 0
printf( "stem (%d,%d) adjusted (%.1f,%.1f)\n",
edge - edges, edge2 - edges,
( edge->pos - edge->opos ) / 64.0,
( edge2->pos - edge2->opos ) / 64.0 );
#endif
anchor = edge;
edge->flags |= AF_EDGE_DONE;
edge2->flags |= AF_EDGE_DONE;
}
/* make sure that lowercase m's maintain their symmetry */
/* In general, lowercase m's have six vertical edges if they are sans */
/* serif, or twelve if they are with serifs. This implementation is */
/* based on that assumption, and seems to work very well with most */
/* faces. However, if for a certain face this assumption is not */
/* true, the m is just rendered like before. In addition, any stem */
/* correction will only be applied to symmetrical glyphs (even if the */
/* glyph is not an m), so the potential for unwanted distortion is */
/* relatively low. */
/* We don't handle horizontal edges since we can't easily assure that */
/* the third (lowest) stem aligns with the base line; it might end up */
/* one pixel higher or lower. */
n_edges = edge_limit - edges;
if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) )
{
AF_Edge edge1, edge2, edge3;
FT_Pos dist1, dist2, span;
if ( n_edges == 6 )
{
edge1 = edges;
edge2 = edges + 2;
edge3 = edges + 4;
}
else
{
edge1 = edges + 1;
edge2 = edges + 5;
edge3 = edges + 9;
}
dist1 = edge2->opos - edge1->opos;
dist2 = edge3->opos - edge2->opos;
span = dist1 - dist2;
if ( span < 0 )
span = -span;
if ( edge1->link == edge1 + 1 &&
edge2->link == edge2 + 1 &&
edge3->link == edge3 + 1 && span < 8 )
{
delta = edge3->pos - ( 2 * edge2->pos - edge1->pos );
edge3->pos -= delta;
if ( edge3->link )
edge3->link->pos -= delta;
/* move the serifs along with the stem */
if ( n_edges == 12 )
{
( edges + 8 )->pos -= delta;
( edges + 11 )->pos -= delta;
}
edge3->flags |= AF_EDGE_DONE;
if ( edge3->link )
edge3->link->flags |= AF_EDGE_DONE;
}
}
if ( !skipped )
return;
/*
* now hint the remaining edges (serifs and single) in order
* to complete our processing
*/
for ( edge = edges; edge < edge_limit; edge++ )
{
if ( edge->flags & AF_EDGE_DONE )
continue;
if ( edge->serif )
{
af_cjk_align_serif_edge( hints, edge->serif, edge );
edge->flags |= AF_EDGE_DONE;
skipped--;
}
}
if ( !skipped )
return;
for ( edge = edges; edge < edge_limit; edge++ )
{
AF_Edge before, after;
if ( edge->flags & AF_EDGE_DONE )
continue;
before = after = edge;
while ( --before >= edges )
if ( before->flags & AF_EDGE_DONE )
break;
while ( ++after < edge_limit )
if ( after->flags & AF_EDGE_DONE )
break;
if ( before >= edges || after < edge_limit )
{
if ( before < edges )
af_cjk_align_serif_edge( hints, after, edge );
else if ( after >= edge_limit )
af_cjk_align_serif_edge( hints, before, edge );
else
edge->pos = before->pos +
FT_MulDiv( edge->fpos - before->fpos,
after->pos - before->pos,
after->fpos - before->fpos );
}
}
}
static void
af_cjk_align_edge_points( AF_GlyphHints hints,
AF_Dimension dim )
{
AF_AxisHints axis = & hints->axis[dim];
AF_Edge edges = axis->edges;
AF_Edge edge_limit = edges + axis->num_edges;
AF_Edge edge;
FT_Bool snapping;
snapping = ( ( dim == AF_DIMENSION_HORZ &&
AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) ||
( dim == AF_DIMENSION_VERT &&
AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) );
for ( edge = edges; edge < edge_limit; edge++ )
{
/* move the points of each segment */
/* in each edge to the edge's position */
AF_Segment seg = edge->first;
if ( snapping )
{
do
{
AF_Point point = seg->first;
for (;;)
{
if ( dim == AF_DIMENSION_HORZ )
{
point->x = edge->pos;
point->flags |= AF_FLAG_TOUCH_X;
}
else
{
point->y = edge->pos;
point->flags |= AF_FLAG_TOUCH_Y;
}
if ( point == seg->last )
break;
point = point->next;
}
seg = seg->edge_next;
} while ( seg != edge->first );
}
else
{
FT_Pos delta = edge->pos - edge->opos;
do
{
AF_Point point = seg->first;
for (;;)
{
if ( dim == AF_DIMENSION_HORZ )
{
point->x += delta;
point->flags |= AF_FLAG_TOUCH_X;
}
else
{
point->y += delta;
point->flags |= AF_FLAG_TOUCH_Y;
}
if ( point == seg->last )
break;
point = point->next;
}
seg = seg->edge_next;
} while ( seg != edge->first );
}
}
}
static FT_Error
af_cjk_hints_apply( AF_GlyphHints hints,
FT_Outline* outline,
AF_LatinMetrics metrics )
{
FT_Error error;
int dim;
FT_UNUSED( metrics );
error = af_glyph_hints_reload( hints, outline );
if ( error )
goto Exit;
/* analyze glyph outline */
if ( AF_HINTS_DO_HORIZONTAL( hints ) )
{
error = af_cjk_hints_detect_features( hints, AF_DIMENSION_HORZ );
if ( error )
goto Exit;
}
if ( AF_HINTS_DO_VERTICAL( hints ) )
{
error = af_cjk_hints_detect_features( hints, AF_DIMENSION_VERT );
if ( error )
goto Exit;
}
/* grid-fit the outline */
for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
{
if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) ||
( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) ) )
{
#ifdef AF_USE_WARPER
if ( dim == AF_DIMENSION_HORZ &&
metrics->root.scaler.render_mode == FT_RENDER_MODE_NORMAL )
{
AF_WarperRec warper;
FT_Fixed scale;
FT_Pos delta;
af_warper_compute( &warper, hints, dim, &scale, &delta );
af_glyph_hints_scale_dim( hints, dim, scale, delta );
continue;
}
#endif /* AF_USE_WARPER */
af_cjk_hint_edges( hints, (AF_Dimension)dim );
af_cjk_align_edge_points( hints, (AF_Dimension)dim );
af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim );
af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim );
}
}
#if 0
af_glyph_hints_dump_points( hints );
af_glyph_hints_dump_segments( hints );
af_glyph_hints_dump_edges( hints );
#endif
af_glyph_hints_save( hints, outline );
Exit:
return error;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** C J K S C R I P T C L A S S *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
static const AF_Script_UniRangeRec af_cjk_uniranges[] =
{
{ 0x0100, 0xFFFF },
{ 0x2E80, 0x2EFF }, /* CJK Radicals Supplement */
{ 0x2F00, 0x2FDF }, /* Kangxi Radicals */
{ 0x3000, 0x303F }, /* CJK Symbols and Punctuation */
{ 0x3040, 0x309F }, /* Hiragana */
{ 0x30A0, 0x30FF }, /* Katakana */
{ 0x3100, 0x312F }, /* Bopomofo */
{ 0x3130, 0x318F }, /* Hangul Compatibility Jamo */
{ 0x31A0, 0x31BF }, /* Bopomofo Extended */
{ 0x31C0, 0x31EF }, /* CJK Strokes */
{ 0x31F0, 0x31FF }, /* Katakana Phonetic Extensions */
{ 0x3200, 0x32FF }, /* Enclosed CJK Letters and Months */
{ 0x3300, 0x33FF }, /* CJK Compatibility */
{ 0x3400, 0x4DBF }, /* CJK Unified Ideographs Extension A */
{ 0x4DC0, 0x4DFF }, /* Yijing Hexagram Symbols */
{ 0x4E00, 0x9FFF }, /* CJK Unified Ideographs */
{ 0xF900, 0xFAFF }, /* CJK Compatibility Ideographs */
{ 0xFE30, 0xFE4F }, /* CJK Compatibility Forms */
{ 0xFF00, 0xFFEF }, /* Halfwidth and Fullwidth Forms */
{ 0x20000, 0x2A6DF }, /* CJK Unified Ideographs Extension B */
{ 0x2F800, 0x2FA1F }, /* CJK Compatibility Ideographs Supplement */
{ 0, 0 }
};
FT_CALLBACK_TABLE_DEF const AF_ScriptClassRec
af_cjk_script_class =
{
AF_SCRIPT_CJK,
af_cjk_uniranges,
sizeof( AF_LatinMetricsRec ),
(AF_Script_InitMetricsFunc) af_cjk_metrics_init,
(AF_Script_ScaleMetricsFunc)af_cjk_metrics_scale,
(AF_Script_DoneMetricsFunc) NULL,
(AF_Script_InitHintsFunc) af_cjk_hints_init,
(AF_Script_ApplyHintsFunc) af_cjk_hints_apply
};
#else /* !AF_MOD_CJK */
static const AF_Script_UniRangeRec af_cjk_uniranges[] =
{
{ 0, 0 }
};
FT_CALLBACK_TABLE_DEF const AF_ScriptClassRec
af_cjk_script_class =
{
AF_SCRIPT_CJK,
af_cjk_uniranges,
sizeof( AF_LatinMetricsRec ),
(AF_Script_InitMetricsFunc) NULL,
(AF_Script_ScaleMetricsFunc)NULL,
(AF_Script_DoneMetricsFunc) NULL,
(AF_Script_InitHintsFunc) NULL,
(AF_Script_ApplyHintsFunc) NULL
};
#endif /* !AF_MOD_CJK */
/* END */