- Implement AI land marks which only used to tracks visited areas on the map for now. Significantly reduces wasting of cpu time by AI checking same place several times (10x or even more in rare cases)
- More branching in walk algorythm which allows for better coverage of reachable places. Sometimes makes AI perform ridiculous jumping just to make a tiny step.
- Small fixes/adjustments
/***************************************************************************/
/* */
/* aflatin.c */
/* */
/* Auto-fitter hinting routines for latin script (body). */
/* */
/* Copyright 2003-2011 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. */
/* */
/***************************************************************************/
#include <ft2build.h>
#include FT_ADVANCES_H
#include FT_INTERNAL_DEBUG_H
#include "aflatin.h"
#include "aferrors.h"
#ifdef AF_CONFIG_OPTION_USE_WARPER
#include "afwarp.h"
#endif
/*************************************************************************/
/* */
/* 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 trace_aflatin
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** L A T I N G L O B A L M E T R I C S *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* Find segments and links, compute all stem widths, and initialize */
/* standard width and height for the glyph with given charcode. */
FT_LOCAL_DEF( void )
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 = 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_ScriptMetrics)dummy );
error = af_glyph_hints_reload( hints, &face->glyph->outline );
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 );
}
#define AF_LATIN_MAX_TEST_CHARACTERS 12
static const char af_latin_blue_chars[AF_LATIN_MAX_BLUES]
[AF_LATIN_MAX_TEST_CHARACTERS + 1] =
{
"THEZOCQS",
"HEZLOCUS",
"fijkdbh",
"xzroesc",
"xzroesc",
"pqgjy"
};
/* Find all blue zones. Flat segments give the reference points, */
/* round segments the overshoot positions. */
static void
af_latin_metrics_init_blues( AF_LatinMetrics metrics,
FT_Face face )
{
FT_Pos flats [AF_LATIN_MAX_TEST_CHARACTERS];
FT_Pos rounds[AF_LATIN_MAX_TEST_CHARACTERS];
FT_Int num_flats;
FT_Int num_rounds;
FT_Int bb;
AF_LatinBlue blue;
FT_Error error;
AF_LatinAxis axis = &metrics->axis[AF_DIMENSION_VERT];
FT_GlyphSlot glyph = face->glyph;
/* we compute the blues simply by loading each character from the */
/* `af_latin_blue_chars[blues]' string, then finding its top-most or */
/* bottom-most points (depending on `AF_IS_TOP_BLUE') */
FT_TRACE5(( "blue zones computation\n" ));
FT_TRACE5(( "------------------------------------------------\n" ));
for ( bb = 0; bb < AF_LATIN_BLUE_MAX; bb++ )
{
const char* p = af_latin_blue_chars[bb];
const char* limit = p + AF_LATIN_MAX_TEST_CHARACTERS;
FT_Pos* blue_ref;
FT_Pos* blue_shoot;
FT_TRACE5(( "blue %3d: ", bb ));
num_flats = 0;
num_rounds = 0;
for ( ; p < limit && *p; p++ )
{
FT_UInt glyph_index;
FT_Pos best_y; /* same as points.y */
FT_Int best_point, best_first, best_last;
FT_Vector* points;
FT_Bool round = 0;
FT_TRACE5(( "'%c'", *p ));
/* load the character in the face -- skip unknown or empty ones */
glyph_index = FT_Get_Char_Index( face, (FT_UInt)*p );
if ( glyph_index == 0 )
continue;
error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
if ( error || glyph->outline.n_points <= 0 )
continue;
/* now compute min or max point indices and coordinates */
points = glyph->outline.points;
best_point = -1;
best_y = 0; /* make compiler happy */
best_first = 0; /* ditto */
best_last = 0; /* ditto */
{
FT_Int nn;
FT_Int first = 0;
FT_Int last = -1;
for ( nn = 0;
nn < glyph->outline.n_contours;
first = last + 1, nn++ )
{
FT_Int old_best_point = best_point;
FT_Int pp;
last = glyph->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_LATIN_IS_TOP_BLUE( bb ) )
{
for ( pp = first; pp <= last; pp++ )
if ( best_point < 0 || points[pp].y > best_y )
{
best_point = pp;
best_y = points[pp].y;
}
}
else
{
for ( pp = first; pp <= last; pp++ )
if ( best_point < 0 || points[pp].y < best_y )
{
best_point = pp;
best_y = points[pp].y;
}
}
if ( best_point != old_best_point )
{
best_first = first;
best_last = last;
}
}
FT_TRACE5(( "%5d", best_y ));
}
/* now check whether the point belongs to a straight or round */
/* segment; we first need to find in which contour the extremum */
/* lies, then inspect its previous and next points */
if ( best_point >= 0 )
{
FT_Int prev, next;
FT_Pos dist;
/* now look for the previous and next points that are not on the */
/* same Y coordinate. Threshold the `closeness'... */
prev = best_point;
next = prev;
do
{
if ( prev > best_first )
prev--;
else
prev = best_last;
dist = points[prev].y - best_y;
if ( dist < -5 || dist > 5 )
break;
} while ( prev != best_point );
do
{
if ( next < best_last )
next++;
else
next = best_first;
dist = points[next].y - best_y;
if ( dist < -5 || dist > 5 )
break;
} while ( next != best_point );
/* now set the `round' flag depending on the segment's kind */
round = FT_BOOL(
FT_CURVE_TAG( glyph->outline.tags[prev] ) != FT_CURVE_TAG_ON ||
FT_CURVE_TAG( glyph->outline.tags[next] ) != FT_CURVE_TAG_ON );
FT_TRACE5(( "%c ", round ? 'r' : 'f' ));
}
if ( round )
rounds[num_rounds++] = best_y;
else
flats[num_flats++] = best_y;
}
FT_TRACE5(( "\n" ));
if ( num_flats == 0 && num_rounds == 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 `rounds' 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_rounds, rounds );
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 = rounds[num_rounds / 2];
}
else if ( num_rounds == 0 )
{
*blue_ref =
*blue_shoot = flats[num_flats / 2];
}
else
{
*blue_ref = flats[num_flats / 2];
*blue_shoot = rounds[num_rounds / 2];
}
/* there are sometimes problems: if the overshoot position of top */
/* zones is under its reference position, or the opposite for bottom */
/* zones. We must thus check everything there and correct the errors */
if ( *blue_shoot != *blue_ref )
{
FT_Pos ref = *blue_ref;
FT_Pos shoot = *blue_shoot;
FT_Bool over_ref = FT_BOOL( shoot > ref );
if ( AF_LATIN_IS_TOP_BLUE( bb ) ^ over_ref )
*blue_ref =
*blue_shoot = ( shoot + ref ) / 2;
}
blue->flags = 0;
if ( AF_LATIN_IS_TOP_BLUE( bb ) )
blue->flags |= AF_LATIN_BLUE_TOP;
/*
* The following flag is used later to adjust the y and x scales
* in order to optimize the pixel grid alignment of the top of small
* letters.
*/
if ( bb == AF_LATIN_BLUE_SMALL_TOP )
blue->flags |= AF_LATIN_BLUE_ADJUSTMENT;
FT_TRACE5(( "-- ref = %ld, shoot = %ld\n", *blue_ref, *blue_shoot ));
}
return;
}
/* Check whether all ASCII digits have the same advance width. */
FT_LOCAL_DEF( void )
af_latin_metrics_check_digits( AF_LatinMetrics metrics,
FT_Face face )
{
FT_UInt i;
FT_Bool started = 0, same_width = 1;
FT_Fixed advance, old_advance = 0;
/* digit `0' is 0x30 in all supported charmaps */
for ( i = 0x30; i <= 0x39; i++ )
{
FT_UInt glyph_index;
glyph_index = FT_Get_Char_Index( face, i );
if ( glyph_index == 0 )
continue;
if ( FT_Get_Advance( face, glyph_index,
FT_LOAD_NO_SCALE |
FT_LOAD_NO_HINTING |
FT_LOAD_IGNORE_TRANSFORM,
&advance ) )
continue;
if ( started )
{
if ( advance != old_advance )
{
same_width = 0;
break;
}
}
else
{
old_advance = advance;
started = 1;
}
}
metrics->root.digits_have_same_width = same_width;
}
/* Initialize global metrics. */
FT_LOCAL_DEF( FT_Error )
af_latin_metrics_init( AF_LatinMetrics metrics,
FT_Face face )
{
FT_Error error = AF_Err_Ok;
FT_CharMap oldmap = face->charmap;
FT_UInt ee;
static const FT_Encoding latin_encodings[] =
{
FT_ENCODING_UNICODE,
FT_ENCODING_APPLE_ROMAN,
FT_ENCODING_ADOBE_STANDARD,
FT_ENCODING_ADOBE_LATIN_1,
FT_ENCODING_NONE /* end of list */
};
metrics->units_per_em = face->units_per_EM;
/* do we have a latin charmap in there? */
for ( ee = 0; latin_encodings[ee] != FT_ENCODING_NONE; ee++ )
{
error = FT_Select_Charmap( face, latin_encodings[ee] );
if ( !error )
break;
}
if ( !error )
{
/* For now, compute the standard width and height from the `o'. */
af_latin_metrics_init_widths( metrics, face, 'o' );
af_latin_metrics_init_blues( metrics, face );
af_latin_metrics_check_digits( metrics, face );
}
FT_Set_Charmap( face, oldmap );
return AF_Err_Ok;
}
/* Adjust scaling value, then scale and shift widths */
/* and blue zones (if applicable) for given dimension. */
static void
af_latin_metrics_scale_dim( AF_LatinMetrics metrics,
AF_Scaler scaler,
AF_Dimension dim )
{
FT_Fixed scale;
FT_Pos delta;
AF_LatinAxis 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;
/*
* correct X and Y scale to optimize the alignment of the top of small
* letters to the pixel grid
*/
{
AF_LatinAxis Axis = &metrics->axis[AF_DIMENSION_VERT];
AF_LatinBlue blue = NULL;
for ( nn = 0; nn < Axis->blue_count; nn++ )
{
if ( Axis->blues[nn].flags & AF_LATIN_BLUE_ADJUSTMENT )
{
blue = &Axis->blues[nn];
break;
}
}
if ( blue )
{
FT_Pos scaled = FT_MulFix( blue->shoot.org, scaler->y_scale );
FT_Pos fitted = ( scaled + 40 ) & ~63;
if ( scaled != fitted )
{
#if 0
if ( dim == AF_DIMENSION_HORZ )
{
if ( fitted < scaled )
scale -= scale / 50; /* scale *= 0.98 */
}
else
#endif
if ( dim == AF_DIMENSION_VERT )
scale = FT_MulDiv( scale, fitted, scaled );
}
}
}
axis->scale = scale;
axis->delta = delta;
if ( dim == AF_DIMENSION_HORZ )
{
metrics->root.scaler.x_scale = scale;
metrics->root.scaler.x_delta = delta;
}
else
{
metrics->root.scaler.y_scale = scale;
metrics->root.scaler.y_delta = delta;
}
/* scale the widths */
for ( nn = 0; nn < axis->width_count; nn++ )
{
AF_Width width = axis->widths + nn;
width->cur = FT_MulFix( width->org, scale );
width->fit = width->cur;
}
/* an extra-light axis corresponds to a standard width that is */
/* smaller than 0.75 pixels */
axis->extra_light =
(FT_Bool)( FT_MulFix( axis->standard_width, scale ) < 32 + 8 );
if ( dim == AF_DIMENSION_VERT )
{
/* scale the blue zones */
for ( nn = 0; nn < axis->blue_count; nn++ )
{
AF_LatinBlue 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_LATIN_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;
delta1 = blue->shoot.org - blue->ref.org;
delta2 = delta1;
if ( delta1 < 0 )
delta2 = -delta2;
delta2 = FT_MulFix( delta2, scale );
if ( delta2 < 32 )
delta2 = 0;
else if ( delta2 < 64 )
delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 );
else
delta2 = FT_PIX_ROUND( delta2 );
if ( delta1 < 0 )
delta2 = -delta2;
blue->ref.fit = FT_PIX_ROUND( blue->ref.cur );
blue->shoot.fit = blue->ref.fit + delta2;
blue->flags |= AF_LATIN_BLUE_ACTIVE;
}
}
}
}
/* Scale global values in both directions. */
FT_LOCAL_DEF( void )
af_latin_metrics_scale( AF_LatinMetrics metrics,
AF_Scaler scaler )
{
metrics->root.scaler.render_mode = scaler->render_mode;
metrics->root.scaler.face = scaler->face;
af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ );
af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT );
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** L A T I N G L Y P H A N A L Y S I S *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* Walk over all contours and compute its segments. */
FT_LOCAL_DEF( FT_Error )
af_latin_hints_compute_segments( AF_GlyphHints hints,
AF_Dimension dim )
{
AF_AxisHints axis = &hints->axis[dim];
FT_Memory memory = hints->memory;
FT_Error error = AF_Err_Ok;
AF_Segment segment = NULL;
AF_SegmentRec seg0;
AF_Point* contour = hints->contours;
AF_Point* contour_limit = contour + hints->num_contours;
AF_Direction major_dir, segment_dir;
FT_ZERO( &seg0 );
seg0.score = 32000;
seg0.flags = AF_EDGE_NORMAL;
major_dir = (AF_Direction)FT_ABS( axis->major_dir );
segment_dir = major_dir;
axis->num_segments = 0;
/* set up (u,v) in each point */
if ( dim == AF_DIMENSION_HORZ )
{
AF_Point point = hints->points;
AF_Point limit = point + hints->num_points;
for ( ; point < limit; point++ )
{
point->u = point->fx;
point->v = point->fy;
}
}
else
{
AF_Point point = hints->points;
AF_Point limit = point + hints->num_points;
for ( ; point < limit; point++ )
{
point->u = point->fy;
point->v = point->fx;
}
}
/* do each contour separately */
for ( ; contour < contour_limit; contour++ )
{
AF_Point point = contour[0];
AF_Point last = point->prev;
int on_edge = 0;
FT_Pos min_pos = 32000; /* minimum segment pos != min_coord */
FT_Pos max_pos = -32000; /* maximum segment pos != max_coord */
FT_Bool passed;
if ( point == last ) /* skip singletons -- just in case */
continue;
if ( FT_ABS( last->out_dir ) == major_dir &&
FT_ABS( point->out_dir ) == major_dir )
{
/* we are already on an edge, try to locate its start */
last = point;
for (;;)
{
point = point->prev;
if ( FT_ABS( point->out_dir ) != major_dir )
{
point = point->next;
break;
}
if ( point == last )
break;
}
}
last = point;
passed = 0;
for (;;)
{
FT_Pos u, v;
if ( on_edge )
{
u = point->u;
if ( u < min_pos )
min_pos = u;
if ( u > max_pos )
max_pos = u;
if ( point->out_dir != segment_dir || point == last )
{
/* we are just leaving an edge; record a new segment! */
segment->last = point;
segment->pos = (FT_Short)( ( min_pos + max_pos ) >> 1 );
/* a segment is round if either its first or last point */
/* is a control point */
if ( ( segment->first->flags | point->flags ) &
AF_FLAG_CONTROL )
segment->flags |= AF_EDGE_ROUND;
/* compute segment size */
min_pos = max_pos = point->v;
v = segment->first->v;
if ( v < min_pos )
min_pos = v;
if ( v > max_pos )
max_pos = v;
segment->min_coord = (FT_Short)min_pos;
segment->max_coord = (FT_Short)max_pos;
segment->height = (FT_Short)( segment->max_coord -
segment->min_coord );
on_edge = 0;
segment = NULL;
/* fallthrough */
}
}
/* now exit if we are at the start/end point */
if ( point == last )
{
if ( passed )
break;
passed = 1;
}
if ( !on_edge && FT_ABS( point->out_dir ) == major_dir )
{
/* this is the start of a new segment! */
segment_dir = (AF_Direction)point->out_dir;
/* clear all segment fields */
error = af_axis_hints_new_segment( axis, memory, &segment );
if ( error )
goto Exit;
segment[0] = seg0;
segment->dir = (FT_Char)segment_dir;
min_pos = max_pos = point->u;
segment->first = point;
segment->last = point;
segment->contour = contour;
on_edge = 1;
}
point = point->next;
}
} /* contours */
/* now slightly increase the height of segments when this makes */
/* sense -- this is used to better detect and ignore serifs */
{
AF_Segment segments = axis->segments;
AF_Segment segments_end = segments + axis->num_segments;
for ( segment = segments; segment < segments_end; segment++ )
{
AF_Point first = segment->first;
AF_Point last = segment->last;
FT_Pos first_v = first->v;
FT_Pos last_v = last->v;
if ( first == last )
continue;
if ( first_v < last_v )
{
AF_Point p;
p = first->prev;
if ( p->v < first_v )
segment->height = (FT_Short)( segment->height +
( ( first_v - p->v ) >> 1 ) );
p = last->next;
if ( p->v > last_v )
segment->height = (FT_Short)( segment->height +
( ( p->v - last_v ) >> 1 ) );
}
else
{
AF_Point p;
p = first->prev;
if ( p->v > first_v )
segment->height = (FT_Short)( segment->height +
( ( p->v - first_v ) >> 1 ) );
p = last->next;
if ( p->v < last_v )
segment->height = (FT_Short)( segment->height +
( ( last_v - p->v ) >> 1 ) );
}
}
}
Exit:
return error;
}
/* Link segments to form stems and serifs. */
FT_LOCAL_DEF( void )
af_latin_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;
FT_Pos len_threshold, len_score;
AF_Segment seg1, seg2;
len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 );
if ( len_threshold == 0 )
len_threshold = 1;
len_score = AF_LATIN_CONSTANT( hints->metrics, 6000 );
/* now compare each segment to the others */
for ( seg1 = segments; seg1 < segment_limit; seg1++ )
{
/* the fake segments are introduced to hint the metrics -- */
/* we must never link them to anything */
if ( seg1->dir != axis->major_dir || seg1->first == seg1->last )
continue;
/* search for stems having opposite directions, */
/* with seg1 to the `left' of seg2 */
for ( seg2 = segments; seg2 < segment_limit; seg2++ )
{
FT_Pos pos1 = seg1->pos;
FT_Pos pos2 = seg2->pos;
if ( seg1->dir + seg2->dir == 0 && pos2 > pos1 )
{
/* compute distance between the two segments */
FT_Pos dist = pos2 - pos1;
FT_Pos min = seg1->min_coord;
FT_Pos max = seg1->max_coord;
FT_Pos len, score;
if ( min < seg2->min_coord )
min = seg2->min_coord;
if ( max > seg2->max_coord )
max = seg2->max_coord;
/* compute maximum coordinate difference of the two segments */
len = max - min;
if ( len >= len_threshold )
{
/* small coordinate differences cause a higher score, and */
/* segments with a greater distance cause a higher score also */
score = dist + len_score / len;
/* and we search for the smallest score */
/* of the sum of the two values */
if ( score < seg1->score )
{
seg1->score = score;
seg1->link = seg2;
}
if ( score < seg2->score )
{
seg2->score = score;
seg2->link = seg1;
}
}
}
}
}
/* now compute the `serif' segments, cf. explanations in `afhints.h' */
for ( seg1 = segments; seg1 < segment_limit; seg1++ )
{
seg2 = seg1->link;
if ( seg2 )
{
if ( seg2->link != seg1 )
{
seg1->link = 0;
seg1->serif = seg2->link;
}
}
}
}
/* Link segments to edges, using feature analysis for selection. */
FT_LOCAL_DEF( FT_Error )
af_latin_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;
FT_Pos segment_length_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 ignore all segments that are less than 1 pixel in length
* to avoid many problems with serif fonts. We compute the
* corresponding threshold in font units.
*/
if ( dim == AF_DIMENSION_HORZ )
segment_length_threshold = FT_DivFix( 64, hints->y_scale );
else
segment_length_threshold = 0;
/*********************************************************************/
/* */
/* 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 gets processed in the second step to compute the */
/* edge's properties. */
/* */
/* Note that the table of edges is sorted along the segment/edge */
/* position. */
/* */
/*********************************************************************/
/* assure that edge distance threshold is at least 0.25px */
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 );
for ( seg = segments; seg < segment_limit; seg++ )
{
AF_Edge found = NULL;
FT_Int ee;
if ( seg->height < segment_length_threshold )
continue;
/* A special case for serif edges: If they are smaller than */
/* 1.5 pixels we ignore them. */
if ( seg->serif &&
2 * seg->height < 3 * segment_length_threshold )
continue;
/* 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;
dist = seg->pos - edge->fpos;
if ( dist < 0 )
dist = -dist;
if ( dist < edge_distance_threshold && edge->dir == seg->dir )
{
found = edge;
break;
}
}
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,
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 will 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 = 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? */
#if 0
FT_Pos ups = 0; /* number of upwards segments */
FT_Pos downs = 0; /* number of downwards segments */
#endif
seg = edge->first;
do
{
FT_Bool is_serif;
/* check for roundness of segment */
if ( seg->flags & AF_EDGE_ROUND )
is_round++;
else
is_straight++;
#if 0
/* check for segment direction */
if ( seg->dir == up_dir )
ups += seg->max_coord - seg->min_coord;
else
downs += seg->max_coord - seg->min_coord;
#endif
/* check for links -- if seg->serif is set, then seg->link must */
/* be ignored */
is_serif = (FT_Bool)( seg->serif &&
seg->serif->edge &&
seg->serif->edge != edge );
if ( ( seg->link && seg->link->edge != NULL ) || 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 = seg->pos - seg2->pos;
if ( seg_delta < 0 )
seg_delta = -seg_delta;
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;
#if 0
/* set the edge's main direction */
edge->dir = AF_DIR_NONE;
if ( ups > downs )
edge->dir = (FT_Char)up_dir;
else if ( ups < downs )
edge->dir = (FT_Char)-up_dir;
else if ( ups == downs )
edge->dir = 0; /* both up and down! */
#endif
/* 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;
}
/* Detect segments and edges for given dimension. */
FT_LOCAL_DEF( FT_Error )
af_latin_hints_detect_features( AF_GlyphHints hints,
AF_Dimension dim )
{
FT_Error error;
error = af_latin_hints_compute_segments( hints, dim );
if ( !error )
{
af_latin_hints_link_segments( hints, dim );
error = af_latin_hints_compute_edges( hints, dim );
}
return error;
}
/* Compute all edges which lie within blue zones. */
FT_LOCAL_DEF( void )
af_latin_hints_compute_blue_edges( AF_GlyphHints hints,
AF_LatinMetrics metrics )
{
AF_AxisHints axis = &hints->axis[AF_DIMENSION_VERT];
AF_Edge edge = axis->edges;
AF_Edge edge_limit = edge + axis->num_edges;
AF_LatinAxis latin = &metrics->axis[AF_DIMENSION_VERT];
FT_Fixed scale = latin->scale;
/* compute which blue zones are active, i.e. have their scaled */
/* size < 3/4 pixels */
/* for each horizontal edge search the blue zone which is closest */
for ( ; edge < edge_limit; edge++ )
{
FT_Int bb;
AF_Width best_blue = NULL;
FT_Pos best_dist; /* initial threshold */
/* compute the initial threshold as a fraction of the EM size */
/* (the value 40 is heuristic) */
best_dist = FT_MulFix( metrics->units_per_em / 40, scale );
/* assure a minimum distance of 0.5px */
if ( best_dist > 64 / 2 )
best_dist = 64 / 2;
for ( bb = 0; bb < AF_LATIN_BLUE_MAX; bb++ )
{
AF_LatinBlue blue = latin->blues + bb;
FT_Bool is_top_blue, is_major_dir;
/* skip inactive blue zones (i.e., those that are too large) */
if ( !( blue->flags & AF_LATIN_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_blue = (FT_Byte)( ( blue->flags & AF_LATIN_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_blue ^ is_major_dir )
{
FT_Pos dist;
/* first of all, compare it to the reference position */
dist = edge->fpos - blue->ref.org;
if ( dist < 0 )
dist = -dist;
dist = FT_MulFix( dist, scale );
if ( dist < best_dist )
{
best_dist = dist;
best_blue = &blue->ref;
}
/* now compare it to the overshoot position and check whether */
/* the edge is rounded, and whether the edge is over the */
/* reference position of a top zone, or under the reference */
/* position of a bottom zone */
if ( edge->flags & AF_EDGE_ROUND && dist != 0 )
{
FT_Bool is_under_ref = FT_BOOL( edge->fpos < blue->ref.org );
if ( is_top_blue ^ is_under_ref )
{
dist = edge->fpos - blue->shoot.org;
if ( dist < 0 )
dist = -dist;
dist = FT_MulFix( dist, scale );
if ( dist < best_dist )
{
best_dist = dist;
best_blue = &blue->shoot;
}
}
}
}
}
if ( best_blue )
edge->blue_edge = best_blue;
}
}
/* Initalize hinting engine. */
static FT_Error
af_latin_hints_init( AF_GlyphHints hints,
AF_LatinMetrics metrics )
{
FT_Render_Mode mode;
FT_UInt32 scaler_flags, other_flags;
FT_Face face = metrics->root.scaler.face;
af_glyph_hints_rescale( hints, (AF_ScriptMetrics)metrics );
/*
* correct x_scale and y_scale if needed, since they may have
* been modified by `af_latin_metrics_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;
#if 0 /* #ifdef AF_CONFIG_OPTION_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;
/*
* In `light' hinting mode we disable horizontal hinting completely.
* We also do it if the face is italic.
*/
if ( mode == FT_RENDER_MODE_LIGHT ||
( face->style_flags & FT_STYLE_FLAG_ITALIC ) != 0 )
scaler_flags |= AF_SCALER_FLAG_NO_HORIZONTAL;
hints->scaler_flags = scaler_flags;
hints->other_flags = other_flags;
return AF_Err_Ok;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** L A T I N 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_latin_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, ignoring very thin ones. */
/* There is a lot of voodoo in this function; changing the hard-coded */
/* parameters influence the whole hinting process. */
static FT_Pos
af_latin_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 );
if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) ||
axis->extra_light )
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 */
/* leave the widths of serifs alone */
if ( ( stem_flags & AF_EDGE_SERIF ) &&
vertical &&
( dist < 3 * 64 ) )
goto Done_Width;
else if ( base_flags & AF_EDGE_ROUND )
{
if ( dist < 80 )
dist = 64;
}
else if ( dist < 56 )
dist = 56;
if ( axis->width_count > 0 )
{
FT_Pos delta;
/* compare to standard width */
delta = dist - axis->widths[0].cur;
if ( delta < 0 )
delta = -delta;
if ( delta < 40 )
{
dist = axis->widths[0].cur;
if ( dist < 48 )
dist = 48;
goto Done_Width;
}
if ( dist < 3 * 64 )
{
delta = dist & 63;
dist &= -64;
if ( delta < 10 )
dist += delta;
else if ( delta < 32 )
dist += 10;
else if ( delta < 54 )
dist += 54;
else
dist += delta;
}
else
dist = ( dist + 32 ) & ~63;
}
}
else
{
/* strong hinting process: snap the stem width to integer pixels */
FT_Pos org_dist = dist;
dist = af_latin_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 )
{
/* We only round to an integer width if the corresponding */
/* distortion is less than 1/4 pixel. Otherwise this */
/* makes everything worse since the diagonals, which are */
/* not hinted, appear a lot bolder or thinner than the */
/* vertical stems. */
FT_Pos delta;
dist = ( dist + 22 ) & ~63;
delta = dist - org_dist;
if ( delta < 0 )
delta = -delta;
if (delta >= 16)
{
dist = org_dist;
if ( dist < 48 )
dist = ( dist + 64 ) >> 1;
}
}
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_latin_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_latin_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;
FT_TRACE5(( "LINK: edge %d (opos=%.2f) linked to (%.2f),"
" dist was %.2f, now %.2f\n",
stem_edge-hints->axis[dim].edges, stem_edge->opos / 64.0,
stem_edge->pos / 64.0, dist / 64.0, fitted_width / 64.0 ));
}
/* Shift the coordinates of the `serif' edge by the same amount */
/* as the corresponding `base' edge has been moved already. */
static void
af_latin_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 ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/* The main grid-fitting routine. */
FT_LOCAL_DEF( void )
af_latin_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_PtrDist n_edges;
AF_Edge edge;
AF_Edge anchor = NULL;
FT_Int has_serifs = 0;
/* we begin by aligning all stems relative to the blue zone */
/* if needed -- that's only for horizontal edges */
if ( dim == AF_DIMENSION_VERT && 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;
FT_TRACE5(( "BLUE: edge %d (opos=%.2f) snapped to (%.2f),"
" was (%.2f)\n",
edge1 - edges, edge1->opos / 64.0, blue->fit / 64.0,
edge1->pos / 64.0 ));
edge1->pos = blue->fit;
edge1->flags |= AF_EDGE_DONE;
if ( edge2 && !edge2->blue_edge )
{
af_latin_align_linked_edge( hints, dim, edge1, edge2 );
edge2->flags |= AF_EDGE_DONE;
}
if ( !anchor )
anchor = edge;
}
}
/* now we align all stem edges, trying to maintain the */
/* relative order of stems in the glyph */
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 )
{
has_serifs++;
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 %d\n", edge2-edges ));
af_latin_align_linked_edge( hints, dim, edge2, edge );
edge->flags |= AF_EDGE_DONE;
continue;
}
if ( !anchor )
{
FT_Pos org_len, org_center, cur_len;
FT_Pos cur_pos1, error1, error2, u_off, d_off;
org_len = edge2->opos - edge->opos;
cur_len = af_latin_compute_stem_width(
hints, dim, org_len,
(AF_Edge_Flags)edge->flags,
(AF_Edge_Flags)edge2->flags );
/* some voodoo to specially round edges for small stem widths */
if ( cur_len <= 64 )
{
u_off = 32;
d_off = 32;
}
else
{
u_off = 38;
d_off = 26;
}
if ( cur_len < 96 )
{
org_center = edge->opos + ( org_len >> 1 );
cur_pos1 = FT_PIX_ROUND( org_center );
error1 = org_center - ( cur_pos1 - u_off );
if ( error1 < 0 )
error1 = -error1;
error2 = org_center - ( cur_pos1 + d_off );
if ( error2 < 0 )
error2 = -error2;
if ( error1 < error2 )
cur_pos1 -= u_off;
else
cur_pos1 += d_off;
edge->pos = cur_pos1 - cur_len / 2;
edge2->pos = edge->pos + cur_len;
}
else
edge->pos = FT_PIX_ROUND( edge->opos );
FT_TRACE5(( "ANCHOR: edge %d (opos=%.2f) and %d (opos=%.2f)"
" snapped to (%.2f) (%.2f)\n",
edge - edges, edge->opos / 64.0,
edge2 - edges, edge2->opos / 64.0,
edge->pos / 64.0, edge2->pos / 64.0 ));
anchor = edge;
edge->flags |= AF_EDGE_DONE;
af_latin_align_linked_edge( hints, dim, edge, edge2 );
}
else
{
FT_Pos org_pos, org_len, org_center, cur_len;
FT_Pos cur_pos1, cur_pos2, delta1, delta2;
org_pos = anchor->pos + ( edge->opos - anchor->opos );
org_len = edge2->opos - edge->opos;
org_center = org_pos + ( org_len >> 1 );
cur_len = af_latin_compute_stem_width(
hints, dim, org_len,
(AF_Edge_Flags)edge->flags,
(AF_Edge_Flags)edge2->flags );
if ( edge2->flags & AF_EDGE_DONE )
edge->pos = edge2->pos - cur_len;
else if ( cur_len < 96 )
{
FT_Pos u_off, d_off;
cur_pos1 = FT_PIX_ROUND( org_center );
if (cur_len <= 64 )
{
u_off = 32;
d_off = 32;
}
else
{
u_off = 38;
d_off = 26;
}
delta1 = org_center - ( cur_pos1 - u_off );
if ( delta1 < 0 )
delta1 = -delta1;
delta2 = org_center - ( cur_pos1 + d_off );
if ( delta2 < 0 )
delta2 = -delta2;
if ( delta1 < delta2 )
cur_pos1 -= u_off;
else
cur_pos1 += d_off;
edge->pos = cur_pos1 - cur_len / 2;
edge2->pos = cur_pos1 + cur_len / 2;
FT_TRACE5(( "STEM: %d (opos=%.2f) to %d (opos=%.2f)"
" snapped to (%.2f) and (%.2f)\n",
edge - edges, edge->opos / 64.0,
edge2 - edges, edge2->opos / 64.0,
edge->pos / 64.0, edge2->pos / 64.0 ));
}
else
{
org_pos = anchor->pos + ( edge->opos - anchor->opos );
org_len = edge2->opos - edge->opos;
org_center = org_pos + ( org_len >> 1 );
cur_len = af_latin_compute_stem_width(
hints, dim, org_len,
(AF_Edge_Flags)edge->flags,
(AF_Edge_Flags)edge2->flags );
cur_pos1 = FT_PIX_ROUND( org_pos );
delta1 = cur_pos1 + ( cur_len >> 1 ) - org_center;
if ( delta1 < 0 )
delta1 = -delta1;
cur_pos2 = FT_PIX_ROUND( org_pos + org_len ) - cur_len;
delta2 = cur_pos2 + ( cur_len >> 1 ) - org_center;
if ( delta2 < 0 )
delta2 = -delta2;
edge->pos = ( delta1 < delta2 ) ? cur_pos1 : cur_pos2;
edge2->pos = edge->pos + cur_len;
FT_TRACE5(( "STEM: %d (opos=%.2f) to %d (opos=%.2f)"
" snapped to (%.2f) and (%.2f)\n",
edge - edges, edge->opos / 64.0,
edge2 - edges, edge2->opos / 64.0,
edge->pos / 64.0, edge2->pos / 64.0 ));
}
edge->flags |= AF_EDGE_DONE;
edge2->flags |= AF_EDGE_DONE;
if ( edge > edges && edge->pos < edge[-1].pos )
{
FT_TRACE5(( "BOUND: %d (pos=%.2f) to (%.2f)\n",
edge - edges, edge->pos / 64.0, edge[-1].pos / 64.0 ));
edge->pos = edge[-1].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, delta;
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 ( 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 ( has_serifs || !anchor )
{
/*
* now hint the remaining edges (serifs and single) in order
* to complete our processing
*/
for ( edge = edges; edge < edge_limit; edge++ )
{
FT_Pos delta;
if ( edge->flags & AF_EDGE_DONE )
continue;
delta = 1000;
if ( edge->serif )
{
delta = edge->serif->opos - edge->opos;
if ( delta < 0 )
delta = -delta;
}
if ( delta < 64 + 16 )
{
af_latin_align_serif_edge( hints, edge->serif, edge );
FT_TRACE5(( "SERIF: edge %d (opos=%.2f) serif to %d (opos=%.2f)"
" aligned to (%.2f)\n",
edge - edges, edge->opos / 64.0,
edge->serif - edges, edge->serif->opos / 64.0,
edge->pos / 64.0 ));
}
else if ( !anchor )
{
FT_TRACE5(( "SERIF_ANCHOR: edge %d (opos=%.2f)"
" snapped to (%.2f)\n",
edge-edges, edge->opos / 64.0, edge->pos / 64.0 ));
edge->pos = FT_PIX_ROUND( edge->opos );
anchor = edge;
}
else
{
AF_Edge before, after;
for ( before = edge - 1; before >= edges; before-- )
if ( before->flags & AF_EDGE_DONE )
break;
for ( after = edge + 1; after < edge_limit; after++ )
if ( after->flags & AF_EDGE_DONE )
break;
if ( before >= edges && before < edge &&
after < edge_limit && after > edge )
{
if ( after->opos == before->opos )
edge->pos = before->pos;
else
edge->pos = before->pos +
FT_MulDiv( edge->opos - before->opos,
after->pos - before->pos,
after->opos - before->opos );
FT_TRACE5(( "SERIF_LINK1: edge %d (opos=%.2f) snapped to (%.2f)"
" from %d (opos=%.2f)\n",
edge - edges, edge->opos / 64.0,
edge->pos / 64.0,
before - edges, before->opos / 64.0 ));
}
else
{
edge->pos = anchor->pos +
( ( edge->opos - anchor->opos + 16 ) & ~31 );
FT_TRACE5(( "SERIF_LINK2: edge %d (opos=%.2f)"
" snapped to (%.2f)\n",
edge - edges, edge->opos / 64.0, edge->pos / 64.0 ));
}
}
edge->flags |= AF_EDGE_DONE;
if ( edge > edges && edge->pos < edge[-1].pos )
edge->pos = edge[-1].pos;
if ( edge + 1 < edge_limit &&
edge[1].flags & AF_EDGE_DONE &&
edge->pos > edge[1].pos )
edge->pos = edge[1].pos;
}
}
}
/* Apply the complete hinting algorithm to a latin glyph. */
static FT_Error
af_latin_hints_apply( AF_GlyphHints hints,
FT_Outline* outline,
AF_LatinMetrics metrics )
{
FT_Error error;
int dim;
error = af_glyph_hints_reload( hints, outline );
if ( error )
goto Exit;
/* analyze glyph outline */
#ifdef AF_CONFIG_OPTION_USE_WARPER
if ( metrics->root.scaler.render_mode == FT_RENDER_MODE_LIGHT ||
AF_HINTS_DO_HORIZONTAL( hints ) )
#else
if ( AF_HINTS_DO_HORIZONTAL( hints ) )
#endif
{
error = af_latin_hints_detect_features( hints, AF_DIMENSION_HORZ );
if ( error )
goto Exit;
}
if ( AF_HINTS_DO_VERTICAL( hints ) )
{
error = af_latin_hints_detect_features( hints, AF_DIMENSION_VERT );
if ( error )
goto Exit;
af_latin_hints_compute_blue_edges( hints, metrics );
}
/* grid-fit the outline */
for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
{
#ifdef AF_CONFIG_OPTION_USE_WARPER
if ( dim == AF_DIMENSION_HORZ &&
metrics->root.scaler.render_mode == FT_RENDER_MODE_LIGHT )
{
AF_WarperRec warper;
FT_Fixed scale;
FT_Pos delta;
af_warper_compute( &warper, hints, (AF_Dimension)dim,
&scale, &delta );
af_glyph_hints_scale_dim( hints, (AF_Dimension)dim,
scale, delta );
continue;
}
#endif
if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) ||
( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) ) )
{
af_latin_hint_edges( hints, (AF_Dimension)dim );
af_glyph_hints_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;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** L A T I N S C R I P T C L A S S *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* XXX: this should probably fine tuned to differentiate better between */
/* scripts... */
static const AF_Script_UniRangeRec af_latin_uniranges[] =
{
AF_UNIRANGE_REC( 0x0020UL, 0x007FUL ), /* Basic Latin (no control chars) */
AF_UNIRANGE_REC( 0x00A0UL, 0x00FFUL ), /* Latin-1 Supplement (no control chars) */
AF_UNIRANGE_REC( 0x0100UL, 0x017FUL ), /* Latin Extended-A */
AF_UNIRANGE_REC( 0x0180UL, 0x024FUL ), /* Latin Extended-B */
AF_UNIRANGE_REC( 0x0250UL, 0x02AFUL ), /* IPA Extensions */
AF_UNIRANGE_REC( 0x02B0UL, 0x02FFUL ), /* Spacing Modifier Letters */
AF_UNIRANGE_REC( 0x0300UL, 0x036FUL ), /* Combining Diacritical Marks */
AF_UNIRANGE_REC( 0x0370UL, 0x03FFUL ), /* Greek and Coptic */
AF_UNIRANGE_REC( 0x0400UL, 0x04FFUL ), /* Cyrillic */
AF_UNIRANGE_REC( 0x0500UL, 0x052FUL ), /* Cyrillic Supplement */
AF_UNIRANGE_REC( 0x1D00UL, 0x1D7FUL ), /* Phonetic Extensions */
AF_UNIRANGE_REC( 0x1D80UL, 0x1DBFUL ), /* Phonetic Extensions Supplement */
AF_UNIRANGE_REC( 0x1DC0UL, 0x1DFFUL ), /* Combining Diacritical Marks Supplement */
AF_UNIRANGE_REC( 0x1E00UL, 0x1EFFUL ), /* Latin Extended Additional */
AF_UNIRANGE_REC( 0x1F00UL, 0x1FFFUL ), /* Greek Extended */
AF_UNIRANGE_REC( 0x2000UL, 0x206FUL ), /* General Punctuation */
AF_UNIRANGE_REC( 0x2070UL, 0x209FUL ), /* Superscripts and Subscripts */
AF_UNIRANGE_REC( 0x20A0UL, 0x20CFUL ), /* Currency Symbols */
AF_UNIRANGE_REC( 0x2150UL, 0x218FUL ), /* Number Forms */
AF_UNIRANGE_REC( 0x2460UL, 0x24FFUL ), /* Enclosed Alphanumerics */
AF_UNIRANGE_REC( 0x2C60UL, 0x2C7FUL ), /* Latin Extended-C */
AF_UNIRANGE_REC( 0x2DE0UL, 0x2DFFUL ), /* Cyrillic Extended-A */
AF_UNIRANGE_REC( 0xA640UL, 0xA69FUL ), /* Cyrillic Extended-B */
AF_UNIRANGE_REC( 0xA720UL, 0xA7FFUL ), /* Latin Extended-D */
AF_UNIRANGE_REC( 0xFB00UL, 0xFB06UL ), /* Alphab. Present. Forms (Latin Ligs) */
AF_UNIRANGE_REC( 0x1D400UL, 0x1D7FFUL ), /* Mathematical Alphanumeric Symbols */
AF_UNIRANGE_REC( 0UL, 0UL )
};
AF_DEFINE_SCRIPT_CLASS(af_latin_script_class,
AF_SCRIPT_LATIN,
af_latin_uniranges,
sizeof( AF_LatinMetricsRec ),
(AF_Script_InitMetricsFunc) af_latin_metrics_init,
(AF_Script_ScaleMetricsFunc)af_latin_metrics_scale,
(AF_Script_DoneMetricsFunc) NULL,
(AF_Script_InitHintsFunc) af_latin_hints_init,
(AF_Script_ApplyHintsFunc) af_latin_hints_apply
)
/* END */