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freetype2/src/autofit/afcjk.c

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/****************************************************************************
*
* afcjk.c
*
* Auto-fitter hinting routines for CJK writing system (body).
*
* Copyright (C) 2006-2023 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, archived at
*
* https://web.archive.org/web/20051219160454/http://www.kde.gr.jp:80/~akito/patch/freetype2/2.1.7/
*
*/
#include <freetype/ftadvanc.h>
#include <freetype/internal/ftdebug.h>
#include "afglobal.h"
#include "aflatin.h"
#include "afcjk.h"
#ifdef AF_CONFIG_OPTION_CJK
#undef AF_CONFIG_OPTION_CJK_BLUE_HANI_VERT
#include "aferrors.h"
/**************************************************************************
*
* The macro FT_COMPONENT is used in trace mode. It is an implicit
* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
* messages during execution.
*/
#undef FT_COMPONENT
#define FT_COMPONENT afcjk
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** C J K G L O B A L M E T R I C S *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* Basically the Latin version with AF_CJKMetrics */
/* to replace AF_LatinMetrics. */
FT_LOCAL_DEF( void )
af_cjk_metrics_init_widths( AF_CJKMetrics metrics,
FT_Face face )
{
/* scan the array of segments in each direction */
AF_GlyphHintsRec hints[1];
FT_TRACE5(( "\n" ));
FT_TRACE5(( "cjk standard widths computation (style `%s')\n",
af_style_names[metrics->root.style_class->style] ));
FT_TRACE5(( "===================================================\n" ));
FT_TRACE5(( "\n" ));
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_ULong glyph_index;
int dim;
AF_CJKMetricsRec dummy[1];
AF_Scaler scaler = &dummy->root.scaler;
AF_StyleClass style_class = metrics->root.style_class;
AF_ScriptClass script_class = af_script_classes[style_class->script];
/* If HarfBuzz is not available, we need a pointer to a single */
/* unsigned long value. */
#ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
void* shaper_buf;
#else
FT_ULong shaper_buf_;
void* shaper_buf = &shaper_buf_;
#endif
const char* p;
#ifdef FT_DEBUG_LEVEL_TRACE
FT_ULong ch = 0;
#endif
p = script_class->standard_charstring;
#ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
shaper_buf = af_shaper_buf_create( face );
#endif
/* We check a list of standard characters. The first match wins. */
glyph_index = 0;
while ( *p )
{
unsigned int num_idx;
#ifdef FT_DEBUG_LEVEL_TRACE
const char* p_old;
#endif
while ( *p == ' ' )
p++;
#ifdef FT_DEBUG_LEVEL_TRACE
p_old = p;
GET_UTF8_CHAR( ch, p_old );
#endif
/* reject input that maps to more than a single glyph */
p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx );
if ( num_idx > 1 )
continue;
/* otherwise exit loop if we have a result */
glyph_index = af_shaper_get_elem( &metrics->root,
shaper_buf,
0,
NULL,
NULL );
if ( glyph_index )
break;
}
af_shaper_buf_destroy( face, shaper_buf );
if ( !glyph_index )
goto Exit;
if ( !glyph_index )
goto Exit;
FT_TRACE5(( "standard character: U+%04lX (glyph index %ld)\n",
ch, glyph_index ));
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 = 0x10000L;
scaler->y_scale = 0x10000L;
scaler->x_delta = 0;
scaler->y_delta = 0;
scaler->face = face;
scaler->render_mode = FT_RENDER_MODE_NORMAL;
scaler->flags = 0;
af_glyph_hints_rescale( hints, (AF_StyleMetrics)dummy );
error = af_glyph_hints_reload( hints, &face->glyph->outline );
if ( error )
goto Exit;
for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
{
AF_CJKAxis 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;
/*
* We assume that the glyphs selected for the stem width
* computation are `featureless' enough so that the linking
* algorithm works fine without adjustments of its scoring
* function.
*/
af_latin_hints_link_segments( hints,
0,
NULL,
(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_CJK_MAX_WIDTHS )
axis->widths[num_widths++].org = dist;
}
}
/* this also replaces multiple almost identical stem widths */
/* with a single one (the value 100 is heuristic) */
af_sort_and_quantize_widths( &num_widths, axis->widths,
dummy->units_per_em / 100 );
axis->width_count = num_widths;
}
Exit:
for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
{
AF_CJKAxis 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;
#ifdef FT_DEBUG_LEVEL_TRACE
{
FT_UInt i;
FT_TRACE5(( "%s widths:\n",
dim == AF_DIMENSION_VERT ? "horizontal"
: "vertical" ));
FT_TRACE5(( " %ld (standard)", axis->standard_width ));
for ( i = 1; i < axis->width_count; i++ )
FT_TRACE5(( " %ld", axis->widths[i].org ));
FT_TRACE5(( "\n" ));
}
#endif
}
}
FT_TRACE5(( "\n" ));
af_glyph_hints_done( hints );
}
/* Find all blue zones. */
static void
af_cjk_metrics_init_blues( AF_CJKMetrics metrics,
FT_Face face )
{
FT_Pos fills[AF_BLUE_STRING_MAX_LEN];
FT_Pos flats[AF_BLUE_STRING_MAX_LEN];
FT_UInt num_fills;
FT_UInt num_flats;
FT_Bool fill;
AF_CJKBlue blue;
FT_Error error;
AF_CJKAxis axis;
FT_Outline outline;
AF_StyleClass sc = metrics->root.style_class;
AF_Blue_Stringset bss = sc->blue_stringset;
const AF_Blue_StringRec* bs = &af_blue_stringsets[bss];
/* If HarfBuzz is not available, we need a pointer to a single */
/* unsigned long value. */
#ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
void* shaper_buf;
#else
FT_ULong shaper_buf_;
void* shaper_buf = &shaper_buf_;
#endif
/* we walk over the blue character strings as specified in the */
/* style's entry in the `af_blue_stringset' array, computing its */
/* extremum points (depending on the string properties) */
FT_TRACE5(( "cjk blue zones computation\n" ));
FT_TRACE5(( "==========================\n" ));
FT_TRACE5(( "\n" ));
#ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
shaper_buf = af_shaper_buf_create( face );
#endif
for ( ; bs->string != AF_BLUE_STRING_MAX; bs++ )
{
const char* p = &af_blue_strings[bs->string];
FT_Pos* blue_ref;
FT_Pos* blue_shoot;
if ( AF_CJK_IS_HORIZ_BLUE( bs ) )
axis = &metrics->axis[AF_DIMENSION_HORZ];
else
axis = &metrics->axis[AF_DIMENSION_VERT];
#ifdef FT_DEBUG_LEVEL_TRACE
{
FT_String* cjk_blue_name[4] =
{
(FT_String*)"bottom", /* -- , -- */
(FT_String*)"top", /* -- , TOP */
(FT_String*)"left", /* HORIZ, -- */
(FT_String*)"right" /* HORIZ, TOP */
};
FT_TRACE5(( "blue zone %d (%s):\n",
axis->blue_count,
cjk_blue_name[AF_CJK_IS_HORIZ_BLUE( bs ) |
AF_CJK_IS_TOP_BLUE( bs ) ] ));
}
#endif /* FT_DEBUG_LEVEL_TRACE */
num_fills = 0;
num_flats = 0;
fill = 1; /* start with characters that define fill values */
FT_TRACE5(( " [overshoot values]\n" ));
while ( *p )
{
FT_ULong glyph_index;
FT_Pos best_pos; /* same as points.y or points.x, resp. */
FT_Int best_point;
FT_Vector* points;
unsigned int num_idx;
#ifdef FT_DEBUG_LEVEL_TRACE
const char* p_old;
FT_ULong ch;
#endif
while ( *p == ' ' )
p++;
#ifdef FT_DEBUG_LEVEL_TRACE
p_old = p;
GET_UTF8_CHAR( ch, p_old );
#endif
/* switch to characters that define flat values */
if ( *p == '|' )
{
fill = 0;
FT_TRACE5(( " [reference values]\n" ));
p++;
continue;
}
/* reject input that maps to more than a single glyph */
p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx );
if ( num_idx > 1 )
continue;
/* load the character in the face -- skip unknown or empty ones */
glyph_index = af_shaper_get_elem( &metrics->root,
shaper_buf,
0,
NULL,
NULL );
if ( glyph_index == 0 )
{
FT_TRACE5(( " U+%04lX unavailable\n", ch ));
continue;
}
error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
outline = face->glyph->outline;
if ( error || outline.n_points <= 2 )
{
FT_TRACE5(( " U+%04lX contains no (usable) outlines\n", ch ));
continue;
}
/* now compute min or max point indices and coordinates */
points = outline.points;
best_point = -1;
best_pos = 0; /* make compiler happy */
{
FT_Int nn;
FT_Int pp, first, last;
last = -1;
for ( nn = 0; nn < outline.n_contours; nn++ )
{
first = last + 1;
last = outline.contours[nn];
/* Avoid single-point contours since they are never rasterized. */
/* In some fonts, they correspond to mark attachment points */
/* which are way outside of the glyph's real outline. */
if ( last <= first )
continue;
if ( AF_CJK_IS_HORIZ_BLUE( bs ) )
{
if ( AF_CJK_IS_RIGHT_BLUE( bs ) )
{
for ( pp = first; pp <= last; pp++ )
if ( best_point < 0 || points[pp].x > best_pos )
{
best_point = pp;
best_pos = points[pp].x;
}
}
else
{
for ( pp = first; pp <= last; pp++ )
if ( best_point < 0 || points[pp].x < best_pos )
{
best_point = pp;
best_pos = points[pp].x;
}
}
}
else
{
if ( AF_CJK_IS_TOP_BLUE( bs ) )
{
for ( pp = first; pp <= last; pp++ )
if ( best_point < 0 || points[pp].y > best_pos )
{
best_point = pp;
best_pos = points[pp].y;
}
}
else
{
for ( pp = first; pp <= last; pp++ )
if ( best_point < 0 || points[pp].y < best_pos )
{
best_point = pp;
best_pos = points[pp].y;
}
}
}
}
FT_TRACE5(( " U+%04lX: best_pos = %5ld\n", ch, best_pos ));
}
if ( fill )
fills[num_fills++] = best_pos;
else
flats[num_flats++] = best_pos;
} /* end while loop */
if ( num_flats == 0 && num_fills == 0 )
{
/*
* we couldn't find a single glyph to compute this blue zone,
* we will simply ignore it then
*/
FT_TRACE5(( " empty\n" ));
continue;
}
/* we have computed the contents of the `fill' and `flats' tables, */
/* now determine the reference and overshoot position of the blue -- */
/* we simply take the median value after a simple sort */
af_sort_pos( num_fills, fills );
af_sort_pos( num_flats, flats );
blue = &axis->blues[axis->blue_count];
blue_ref = &blue->ref.org;
blue_shoot = &blue->shoot.org;
axis->blue_count++;
if ( num_flats == 0 )
{
*blue_ref =
*blue_shoot = fills[num_fills / 2];
}
else if ( num_fills == 0 )
{
*blue_ref =
*blue_shoot = flats[num_flats / 2];
}
else
{
*blue_ref = fills[num_fills / 2];
*blue_shoot = flats[num_flats / 2];
}
/* make sure blue_ref >= blue_shoot for top/right or */
/* vice versa for bottom/left */
if ( *blue_shoot != *blue_ref )
{
FT_Pos ref = *blue_ref;
FT_Pos shoot = *blue_shoot;
FT_Bool under_ref = FT_BOOL( shoot < ref );
/* AF_CJK_IS_TOP_BLUE covers `right' and `top' */
if ( AF_CJK_IS_TOP_BLUE( bs ) ^ under_ref )
{
*blue_ref =
*blue_shoot = ( shoot + ref ) / 2;
FT_TRACE5(( " [reference smaller than overshoot,"
" taking mean value]\n" ));
}
}
blue->flags = 0;
if ( AF_CJK_IS_TOP_BLUE( bs ) )
blue->flags |= AF_CJK_BLUE_TOP;
FT_TRACE5(( " -> reference = %ld\n", *blue_ref ));
FT_TRACE5(( " overshoot = %ld\n", *blue_shoot ));
} /* end for loop */
af_shaper_buf_destroy( face, shaper_buf );
FT_TRACE5(( "\n" ));
return;
}
/* Basically the Latin version with type AF_CJKMetrics for metrics. */
FT_LOCAL_DEF( void )
af_cjk_metrics_check_digits( AF_CJKMetrics metrics,
FT_Face face )
{
FT_Bool started = 0, same_width = 1;
FT_Long advance = 0, old_advance = 0;
/* If HarfBuzz is not available, we need a pointer to a single */
/* unsigned long value. */
#ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
void* shaper_buf;
#else
FT_ULong shaper_buf_;
void* shaper_buf = &shaper_buf_;
#endif
/* in all supported charmaps, digits have character codes 0x30-0x39 */
const char digits[] = "0 1 2 3 4 5 6 7 8 9";
const char* p;
p = digits;
#ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
shaper_buf = af_shaper_buf_create( face );
#endif
while ( *p )
{
FT_ULong glyph_index;
unsigned int num_idx;
/* reject input that maps to more than a single glyph */
p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx );
if ( num_idx > 1 )
continue;
glyph_index = af_shaper_get_elem( &metrics->root,
shaper_buf,
0,
&advance,
NULL );
if ( !glyph_index )
continue;
if ( started )
{
if ( advance != old_advance )
{
same_width = 0;
break;
}
}
else
{
old_advance = advance;
started = 1;
}
}
af_shaper_buf_destroy( face, shaper_buf );
metrics->root.digits_have_same_width = same_width;
}
/* Initialize global metrics. */
FT_LOCAL_DEF( FT_Error )
af_cjk_metrics_init( AF_StyleMetrics metrics_, /* AF_CJKMetrics */
FT_Face face )
{
AF_CJKMetrics metrics = (AF_CJKMetrics)metrics_;
FT_CharMap oldmap = face->charmap;
metrics->units_per_em = face->units_per_EM;
if ( !FT_Select_Charmap( face, FT_ENCODING_UNICODE ) )
{
af_cjk_metrics_init_widths( metrics, face );
af_cjk_metrics_init_blues( metrics, face );
af_cjk_metrics_check_digits( metrics, face );
}
face->charmap = oldmap;
return FT_Err_Ok;
}
/* Adjust scaling value, then scale and shift widths */
/* and blue zones (if applicable) for given dimension. */
static void
af_cjk_metrics_scale_dim( AF_CJKMetrics metrics,
AF_Scaler scaler,
AF_Dimension dim )
{
FT_Fixed scale;
FT_Pos delta;
AF_CJKAxis axis;
FT_UInt nn;
if ( dim == AF_DIMENSION_HORZ )
{
scale = scaler->x_scale;
delta = scaler->x_delta;
}
else
{
scale = scaler->y_scale;
delta = scaler->y_delta;
}
axis = &metrics->axis[dim];
if ( axis->org_scale == scale && axis->org_delta == delta )
return;
axis->org_scale = scale;
axis->org_delta = delta;
axis->scale = scale;
axis->delta = delta;
/* scale the blue zones */
for ( nn = 0; nn < axis->blue_count; nn++ )
{
AF_CJKBlue blue = &axis->blues[nn];
FT_Pos dist;
blue->ref.cur = FT_MulFix( blue->ref.org, scale ) + delta;
blue->ref.fit = blue->ref.cur;
blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta;
blue->shoot.fit = blue->shoot.cur;
blue->flags &= ~AF_CJK_BLUE_ACTIVE;
/* a blue zone is only active if it is less than 3/4 pixels tall */
dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale );
if ( dist <= 48 && dist >= -48 )
{
FT_Pos delta1, delta2;
blue->ref.fit = FT_PIX_ROUND( blue->ref.cur );
/* shoot is under shoot for cjk */
delta1 = FT_DivFix( blue->ref.fit, scale ) - blue->shoot.org;
delta2 = delta1;
if ( delta1 < 0 )
delta2 = -delta2;
delta2 = FT_MulFix( delta2, scale );
FT_TRACE5(( "delta: %ld", delta1 ));
if ( delta2 < 32 )
delta2 = 0;
#if 0
else if ( delta2 < 64 )
delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 );
#endif
else
delta2 = FT_PIX_ROUND( delta2 );
FT_TRACE5(( "/%ld\n", delta2 ));
if ( delta1 < 0 )
delta2 = -delta2;
blue->shoot.fit = blue->ref.fit - delta2;
FT_TRACE5(( ">> active cjk blue zone %c%d[%ld/%ld]:\n",
( dim == AF_DIMENSION_HORZ ) ? 'H' : 'V',
nn, blue->ref.org, blue->shoot.org ));
FT_TRACE5(( " ref: cur=%.2f fit=%.2f\n",
(double)blue->ref.cur / 64,
(double)blue->ref.fit / 64 ));
FT_TRACE5(( " shoot: cur=%.2f fit=%.2f\n",
(double)blue->shoot.cur / 64,
(double)blue->shoot.fit / 64 ));
blue->flags |= AF_CJK_BLUE_ACTIVE;
}
}
}
/* Scale global values in both directions. */
FT_LOCAL_DEF( void )
af_cjk_metrics_scale( AF_StyleMetrics metrics_, /* AF_CJKMetrics */
AF_Scaler scaler )
{
AF_CJKMetrics metrics = (AF_CJKMetrics)metrics_;
/* we copy the whole structure since the x and y scaling values */
/* are not modified, contrary to e.g. the `latin' auto-hinter */
metrics->root.scaler = *scaler;
af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ );
af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT );
}
/* Extract standard_width from writing system/script specific */
/* metrics class. */
FT_CALLBACK_DEF( void )
af_cjk_get_standard_widths( AF_StyleMetrics metrics_, /* AF_CJKMetrics */
FT_Pos* stdHW,
FT_Pos* stdVW )
{
AF_CJKMetrics metrics = (AF_CJKMetrics)metrics_;
if ( stdHW )
*stdHW = metrics->axis[AF_DIMENSION_VERT].standard_width;
if ( stdVW )
*stdVW = metrics->axis[AF_DIMENSION_HORZ].standard_width;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** C J K G L Y P H A N A L Y S I S *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* Walk over all contours and compute its segments. */
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 = FT_OFFSET( 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;
FT_UInt f0 = pt->flags & AF_FLAG_CONTROL;
FT_UInt 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 FT_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 = FT_OFFSET( 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++ )
{
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 = NULL;
seg->serif = link1;
}
else if ( link == link2 )
{
seg->link = NULL;
seg->serif = seg1;
}
}
}
else
{
seg1->link = link1->link = NULL;
break;
}
}
}
}
for ( seg1 = segments; seg1 < segment_limit; seg1++ )
{
seg2 = seg1->link;
if ( seg2 )
{
if ( seg2->link != seg1 )
{
seg1->link = NULL;
if ( seg2->score < dist_threshold || seg1->score < seg2->score * 4 )
seg1->serif = seg2->link;
}
}
}
}
static FT_Error
af_cjk_hints_compute_edges( AF_GlyphHints hints,
AF_Dimension dim )
{
AF_AxisHints axis = &hints->axis[dim];
FT_Error error = FT_Err_Ok;
FT_Memory memory = hints->memory;
AF_CJKAxis laxis = &((AF_CJKMetrics)hints->metrics)->axis[dim];
AF_Segment segments = axis->segments;
AF_Segment segment_limit = FT_OFFSET( segments, axis->num_segments );
AF_Segment seg;
FT_Fixed scale;
FT_Pos edge_distance_threshold;
axis->num_edges = 0;
scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
: hints->y_scale;
/**********************************************************************
*
* 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 = FT_DivFix( 64 / 4, scale );
else
edge_distance_threshold = laxis->edge_distance_threshold;
for ( seg = segments; seg < segment_limit; seg++ )
{
AF_Edge found = NULL;
FT_Pos best = 0xFFFFU;
FT_UInt 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;
FT_Pos dist2 = 0;
do
{
AF_Segment 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,
(AF_Direction)seg->dir, 0,
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->dir = seg->dir;
edge->fpos = seg->pos;
edge->opos = FT_MulFix( seg->pos, scale );
edge->pos = edge->opos;
seg->edge_next = seg;
}
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 the
* segments found on its position. Basically, these are
*
* - the 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 = FT_OFFSET( 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;
if ( !seg )
goto Skip_Loop;
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 );
Skip_Loop:
/* 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 = NULL;
}
}
Exit:
return error;
}
/* Detect segments and edges for given dimension. */
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;
}
/* Compute all edges which lie within blue zones. */
static void
af_cjk_hints_compute_blue_edges( AF_GlyphHints hints,
AF_CJKMetrics metrics,
AF_Dimension dim )
{
AF_AxisHints axis = &hints->axis[dim];
AF_Edge edge = axis->edges;
AF_Edge edge_limit = FT_OFFSET( edge, axis->num_edges );
AF_CJKAxis cjk = &metrics->axis[dim];
FT_Fixed scale = cjk->scale;
FT_Pos best_dist0; /* initial threshold */
/* compute the initial threshold as a fraction of the EM size */
best_dist0 = FT_MulFix( metrics->units_per_em / 40, scale );
if ( best_dist0 > 64 / 2 ) /* maximum 1/2 pixel */
best_dist0 = 64 / 2;
/* compute which blue zones are active, i.e. have their scaled */
/* size < 3/4 pixels */
/* If the distant between an edge and a blue zone is shorter than */
/* best_dist0, set the blue zone for the edge. Then search for */
/* the blue zone with the smallest best_dist to the edge. */
for ( ; edge < edge_limit; edge++ )
{
FT_UInt bb;
AF_Width best_blue = NULL;
FT_Pos best_dist = best_dist0;
for ( bb = 0; bb < cjk->blue_count; bb++ )
{
AF_CJKBlue blue = cjk->blues + bb;
FT_Bool is_top_right_blue, is_major_dir;
/* skip inactive blue zones (i.e., those that are too small) */
if ( !( blue->flags & AF_CJK_BLUE_ACTIVE ) )
continue;
/* if it is a top zone, check for right edges -- if it is a bottom */
/* zone, check for left edges */
/* */
/* of course, that's for TrueType */
is_top_right_blue =
(FT_Byte)( ( blue->flags & AF_CJK_BLUE_TOP ) != 0 );
is_major_dir =
FT_BOOL( edge->dir == axis->major_dir );
/* if it is a top zone, the edge must be against the major */
/* direction; if it is a bottom zone, it must be in the major */
/* direction */
if ( is_top_right_blue ^ is_major_dir )
{
FT_Pos dist;
AF_Width compare;
/* Compare the edge to the closest blue zone type */
if ( FT_ABS( edge->fpos - blue->ref.org ) >
FT_ABS( edge->fpos - blue->shoot.org ) )
compare = &blue->shoot;
else
compare = &blue->ref;
dist = edge->fpos - compare->org;
if ( dist < 0 )
dist = -dist;
dist = FT_MulFix( dist, scale );
if ( dist < best_dist )
{
best_dist = dist;
best_blue = compare;
}
}
}
if ( best_blue )
edge->blue_edge = best_blue;
}
}
/* Initalize hinting engine. */
FT_LOCAL_DEF( FT_Error )
af_cjk_hints_init( AF_GlyphHints hints,
AF_StyleMetrics metrics_ ) /* AF_CJKMetrics */
{
AF_CJKMetrics metrics = (AF_CJKMetrics)metrics_;
FT_Render_Mode mode;
FT_UInt32 scaler_flags, other_flags;
af_glyph_hints_rescale( hints, (AF_StyleMetrics)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;
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 unless in `light' or `lcd' mode.
*/
if ( mode != FT_RENDER_MODE_LIGHT && mode != FT_RENDER_MODE_LCD )
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 FT_Err_Ok;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** 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_UInt count,
FT_Pos width )
{
FT_UInt 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. */
/* There is a lot of voodoo in this function; changing the hard-coded */
/* parameters influence the whole hinting process. */
static FT_Pos
af_cjk_compute_stem_width( AF_GlyphHints hints,
AF_Dimension dim,
FT_Pos width,
FT_UInt base_flags,
FT_UInt stem_flags )
{
AF_CJKMetrics metrics = (AF_CJKMetrics)hints->metrics;
AF_CJKAxis axis = &metrics->axis[dim];
FT_Pos dist = width;
FT_Int sign = 0;
FT_Bool vertical = FT_BOOL( 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,
base_edge->flags,
stem_edge->flags );
stem_edge->pos = base_edge->pos + fitted_width;
FT_TRACE5(( " CJKLINK: edge %ld @%d (opos=%.2f) linked to %.2f,"
" dist was %.2f, now %.2f\n",
stem_edge - hints->axis[dim].edges, stem_edge->fpos,
(double)stem_edge->opos / 64,
(double)stem_edge->pos / 64,
(double)dist / 64,
(double)fitted_width / 64 ));
}
/* Shift the coordinates of the `serif' edge by the same amount */
/* as the corresponding `base' edge has been moved already. */
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 & 63;
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;
}
/* The main grid-fitting routine. */
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 = FT_OFFSET( edges, axis->num_edges );
FT_PtrDist n_edges;
AF_Edge edge;
AF_Edge anchor = NULL;
FT_Pos delta = 0;
FT_Int skipped = 0;
FT_Bool has_last_stem = FALSE;
FT_Pos last_stem_pos = 0;
#ifdef FT_DEBUG_LEVEL_TRACE
FT_UInt num_actions = 0;
#endif
FT_TRACE5(( "cjk %s edge hinting (style `%s')\n",
dim == AF_DIMENSION_VERT ? "horizontal" : "vertical",
af_style_names[hints->metrics->style_class->style] ));
/* we begin by aligning all stems relative to the blue zone */
if ( AF_HINTS_DO_BLUES( hints ) )
{
for ( edge = edges; edge < edge_limit; edge++ )
{
AF_Width blue;
AF_Edge edge1, edge2;
if ( edge->flags & AF_EDGE_DONE )
continue;
blue = edge->blue_edge;
edge1 = NULL;
edge2 = edge->link;
if ( blue )
{
edge1 = edge;
}
else if ( edge2 && edge2->blue_edge )
{
blue = edge2->blue_edge;
edge1 = edge2;
edge2 = edge;
}
if ( !edge1 )
continue;
#ifdef FT_DEBUG_LEVEL_TRACE
FT_TRACE5(( " CJKBLUE: edge %ld @%d (opos=%.2f) snapped to %.2f,"
" was %.2f\n",
edge1 - edges, edge1->fpos, (double)edge1->opos / 64,
(double)blue->fit / 64, (double)edge1->pos / 64 ));
num_actions++;
#endif
edge1->pos = blue->fit;
edge1->flags |= AF_EDGE_DONE;
if ( edge2 && !edge2->blue_edge )
{
af_cjk_align_linked_edge( hints, dim, edge1, edge2 );
edge2->flags |= AF_EDGE_DONE;
#ifdef FT_DEBUG_LEVEL_TRACE
num_actions++;
#endif
}
if ( !anchor )
anchor = edge;
}
}
/* 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;
}
/* Some CJK characters have so many stems that
* the hinter is likely to merge two adjacent ones.
* To solve this problem, if either edge of a stem
* is too close to the previous one, we avoid
* aligning the two edges, but rather interpolate
* their locations at the end of this function in
* order to preserve the space between the stems.
*/
if ( has_last_stem &&
( edge->pos < last_stem_pos + 64 ||
edge2->pos < last_stem_pos + 64 ) )
{
skipped++;
continue;
}
/* now align the stem */
/* this should not happen, but it's better to be safe */
if ( edge2->blue_edge )
{
FT_TRACE5(( "ASSERTION FAILED for edge %ld\n", edge2-edges ));
af_cjk_align_linked_edge( hints, dim, edge2, edge );
edge->flags |= AF_EDGE_DONE;
#ifdef FT_DEBUG_LEVEL_TRACE
num_actions++;
#endif
continue;
}
if ( edge2 < edge )
{
af_cjk_align_linked_edge( hints, dim, edge2, edge );
edge->flags |= AF_EDGE_DONE;
#ifdef FT_DEBUG_LEVEL_TRACE
num_actions++;
#endif
/* We rarely reaches here it seems;
* usually the two edges belonging
* to one stem are marked as DONE together
*/
has_last_stem = TRUE;
last_stem_pos = edge->pos;
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,
AF_DIMENSION_HORZ );
}
else
af_hint_normal_stem( hints, edge, edge2, delta, dim );
#if 0
printf( "stem (%d,%d) adjusted (%.1f,%.1f)\n",
edge - edges, edge2 - edges,
(double)( edge->pos - edge->opos ) / 64,
(double)( edge2->pos - edge2->opos ) / 64 );
#endif
anchor = edge;
edge->flags |= AF_EDGE_DONE;
edge2->flags |= AF_EDGE_DONE;
has_last_stem = TRUE;
last_stem_pos = edge2->pos;
}
/* 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 )
goto Exit;
/*
* 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 )
goto Exit;
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
{
if ( after->fpos == before->fpos )
edge->pos = before->pos;
else
edge->pos = before->pos +
FT_MulDiv( edge->fpos - before->fpos,
after->pos - before->pos,
after->fpos - before->fpos );
}
}
}
Exit:
#ifdef FT_DEBUG_LEVEL_TRACE
if ( !num_actions )
FT_TRACE5(( " (none)\n" ));
FT_TRACE5(( "\n" ));
#endif
return;
}
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 = FT_OFFSET( edges, axis->num_edges );
AF_Edge edge;
FT_Bool snapping;
snapping = FT_BOOL( ( 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 );
}
}
}
/* Apply the complete hinting algorithm to a CJK glyph. */
FT_LOCAL_DEF( FT_Error )
af_cjk_hints_apply( FT_UInt glyph_index,
AF_GlyphHints hints,
FT_Outline* outline,
AF_StyleMetrics metrics_ ) /* AF_CJKMetrics */
{
AF_CJKMetrics metrics = (AF_CJKMetrics)metrics_;
FT_Error error;
int dim;
FT_UNUSED( metrics );
FT_UNUSED( glyph_index );
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;
af_cjk_hints_compute_blue_edges( hints, metrics, AF_DIMENSION_HORZ );
}
if ( AF_HINTS_DO_VERTICAL( hints ) )
{
error = af_cjk_hints_detect_features( hints, AF_DIMENSION_VERT );
if ( error )
goto Exit;
af_cjk_hints_compute_blue_edges( hints, metrics, AF_DIMENSION_VERT );
}
/* 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 ) ) )
{
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 );
}
}
af_glyph_hints_save( hints, outline );
Exit:
return error;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** C J K S C R I P T C L A S S *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
AF_DEFINE_WRITING_SYSTEM_CLASS(
af_cjk_writing_system_class,
AF_WRITING_SYSTEM_CJK,
sizeof ( AF_CJKMetricsRec ),
(AF_WritingSystem_InitMetricsFunc) af_cjk_metrics_init, /* style_metrics_init */
(AF_WritingSystem_ScaleMetricsFunc)af_cjk_metrics_scale, /* style_metrics_scale */
(AF_WritingSystem_DoneMetricsFunc) NULL, /* style_metrics_done */
(AF_WritingSystem_GetStdWidthsFunc)af_cjk_get_standard_widths, /* style_metrics_getstdw */
(AF_WritingSystem_InitHintsFunc) af_cjk_hints_init, /* style_hints_init */
(AF_WritingSystem_ApplyHintsFunc) af_cjk_hints_apply /* style_hints_apply */
)
#else /* !AF_CONFIG_OPTION_CJK */
AF_DEFINE_WRITING_SYSTEM_CLASS(
af_cjk_writing_system_class,
AF_WRITING_SYSTEM_CJK,
sizeof ( AF_CJKMetricsRec ),
(AF_WritingSystem_InitMetricsFunc) NULL, /* style_metrics_init */
(AF_WritingSystem_ScaleMetricsFunc)NULL, /* style_metrics_scale */
(AF_WritingSystem_DoneMetricsFunc) NULL, /* style_metrics_done */
(AF_WritingSystem_GetStdWidthsFunc)NULL, /* style_metrics_getstdw */
(AF_WritingSystem_InitHintsFunc) NULL, /* style_hints_init */
(AF_WritingSystem_ApplyHintsFunc) NULL /* style_hints_apply */
)
#endif /* !AF_CONFIG_OPTION_CJK */
/* END */
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