/***************************************************************************/ | |
/* */ | |
/* aflatin.c */ | |
/* */ | |
/* Auto-fitter hinting routines for latin writing system (body). */ | |
/* */ | |
/* Copyright 2003-2015 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 "afglobal.h" | |
#include "afpic.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 | |
/* needed for computation of round vs. flat segments */ | |
#define FLAT_THRESHOLD( x ) ( x / 14 ) | |
/*************************************************************************/ | |
/*************************************************************************/ | |
/***** *****/ | |
/***** 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 ) | |
{ | |
/* scan the array of segments in each direction */ | |
AF_GlyphHintsRec hints[1]; | |
FT_TRACE5(( "\n" | |
"latin standard widths computation (style `%s')\n" | |
"=====================================================\n" | |
"\n", | |
af_style_names[metrics->root.style_class->style] )); | |
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; | |
FT_Long y_offset; | |
int dim; | |
AF_LatinMetricsRec dummy[1]; | |
AF_Scaler scaler = &dummy->root.scaler; | |
#ifdef FT_CONFIG_OPTION_PIC | |
AF_FaceGlobals globals = metrics->root.globals; | |
#endif | |
AF_StyleClass style_class = metrics->root.style_class; | |
AF_ScriptClass script_class = AF_SCRIPT_CLASSES_GET | |
[style_class->script]; | |
FT_UInt32 standard_char; | |
/* | |
* We check more than a single standard character to catch features | |
* like `c2sc' (small caps from caps) that don't contain lowercase | |
* letters by definition, or other features that mainly operate on | |
* numerals. | |
*/ | |
standard_char = script_class->standard_char1; | |
af_get_char_index( &metrics->root, | |
standard_char, | |
&glyph_index, | |
&y_offset ); | |
if ( !glyph_index ) | |
{ | |
if ( script_class->standard_char2 ) | |
{ | |
standard_char = script_class->standard_char2; | |
af_get_char_index( &metrics->root, | |
standard_char, | |
&glyph_index, | |
&y_offset ); | |
if ( !glyph_index ) | |
{ | |
if ( script_class->standard_char3 ) | |
{ | |
standard_char = script_class->standard_char3; | |
af_get_char_index( &metrics->root, | |
standard_char, | |
&glyph_index, | |
&y_offset ); | |
if ( !glyph_index ) | |
goto Exit; | |
} | |
else | |
goto Exit; | |
} | |
} | |
else | |
goto Exit; | |
} | |
FT_TRACE5(( "standard character: U+%04lX (glyph index %d)\n", | |
standard_char, 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_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; | |
/* | |
* 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_LATIN_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_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; | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
{ | |
FT_UInt i; | |
FT_TRACE5(( "%s widths:\n", | |
dim == AF_DIMENSION_VERT ? "horizontal" | |
: "vertical" )); | |
FT_TRACE5(( " %d (standard)", axis->standard_width )); | |
for ( i = 1; i < axis->width_count; i++ ) | |
FT_TRACE5(( " %d", axis->widths[i].org )); | |
FT_TRACE5(( "\n" )); | |
} | |
#endif | |
} | |
} | |
FT_TRACE5(( "\n" )); | |
af_glyph_hints_done( hints ); | |
} | |
/* 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_BLUE_STRING_MAX_LEN]; | |
FT_Pos rounds[AF_BLUE_STRING_MAX_LEN]; | |
FT_UInt num_flats; | |
FT_UInt num_rounds; | |
AF_LatinBlue blue; | |
FT_Error error; | |
AF_LatinAxis axis = &metrics->axis[AF_DIMENSION_VERT]; | |
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]; | |
FT_Pos flat_threshold = FLAT_THRESHOLD( metrics->units_per_em ); | |
/* we walk over the blue character strings as specified in the */ | |
/* style's entry in the `af_blue_stringset' array */ | |
FT_TRACE5(( "latin blue zones computation\n" | |
"============================\n" | |
"\n" )); | |
for ( ; bs->string != AF_BLUE_STRING_MAX; bs++ ) | |
{ | |
const char* p = &af_blue_strings[bs->string]; | |
FT_Pos* blue_ref; | |
FT_Pos* blue_shoot; | |
FT_Pos ascender; | |
FT_Pos descender; | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
{ | |
FT_Bool have_flag = 0; | |
FT_TRACE5(( "blue zone %d", axis->blue_count )); | |
if ( bs->properties ) | |
{ | |
FT_TRACE5(( " (" )); | |
if ( AF_LATIN_IS_TOP_BLUE( bs ) ) | |
{ | |
FT_TRACE5(( "top" )); | |
have_flag = 1; | |
} | |
if ( AF_LATIN_IS_NEUTRAL_BLUE( bs ) ) | |
{ | |
if ( have_flag ) | |
FT_TRACE5(( ", " )); | |
FT_TRACE5(( "neutral" )); | |
have_flag = 1; | |
} | |
if ( AF_LATIN_IS_X_HEIGHT_BLUE( bs ) ) | |
{ | |
if ( have_flag ) | |
FT_TRACE5(( ", " )); | |
FT_TRACE5(( "small top" )); | |
have_flag = 1; | |
} | |
if ( AF_LATIN_IS_LONG_BLUE( bs ) ) | |
{ | |
if ( have_flag ) | |
FT_TRACE5(( ", " )); | |
FT_TRACE5(( "long" )); | |
} | |
FT_TRACE5(( ")" )); | |
} | |
FT_TRACE5(( ":\n" )); | |
} | |
#endif /* FT_DEBUG_LEVEL_TRACE */ | |
num_flats = 0; | |
num_rounds = 0; | |
ascender = 0; | |
descender = 0; | |
while ( *p ) | |
{ | |
FT_ULong ch; | |
FT_ULong glyph_index; | |
FT_Long y_offset; | |
FT_Pos best_y; /* same as points.y */ | |
FT_Int best_point, best_contour_first, best_contour_last; | |
FT_Vector* points; | |
FT_Bool round = 0; | |
GET_UTF8_CHAR( ch, p ); | |
/* load the character in the face -- skip unknown or empty ones */ | |
af_get_char_index( &metrics->root, ch, &glyph_index, &y_offset ); | |
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; | |
/* reject glyphs that don't produce any rendering */ | |
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_y = 0; /* make compiler happy */ | |
best_contour_first = 0; /* ditto */ | |
best_contour_last = 0; /* ditto */ | |
{ | |
FT_Int nn; | |
FT_Int first = 0; | |
FT_Int last = -1; | |
for ( nn = 0; nn < outline.n_contours; first = last + 1, nn++ ) | |
{ | |
FT_Int old_best_point = best_point; | |
FT_Int pp; | |
last = outline.contours[nn]; | |
/* Avoid single-point contours since they are never rasterized. */ | |
/* In some fonts, they correspond to mark attachment points */ | |
/* that are way outside of the glyph's real outline. */ | |
if ( last <= first ) | |
continue; | |
if ( AF_LATIN_IS_TOP_BLUE( bs ) ) | |
{ | |
for ( pp = first; pp <= last; pp++ ) | |
{ | |
if ( best_point < 0 || points[pp].y > best_y ) | |
{ | |
best_point = pp; | |
best_y = points[pp].y; | |
ascender = FT_MAX( ascender, best_y + y_offset ); | |
} | |
else | |
descender = FT_MIN( descender, points[pp].y + y_offset ); | |
} | |
} | |
else | |
{ | |
for ( pp = first; pp <= last; pp++ ) | |
{ | |
if ( best_point < 0 || points[pp].y < best_y ) | |
{ | |
best_point = pp; | |
best_y = points[pp].y; | |
descender = FT_MIN( descender, best_y + y_offset ); | |
} | |
else | |
ascender = FT_MAX( ascender, points[pp].y + y_offset ); | |
} | |
} | |
if ( best_point != old_best_point ) | |
{ | |
best_contour_first = first; | |
best_contour_last = last; | |
} | |
} | |
} | |
/* 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_Pos best_x = points[best_point].x; | |
FT_Int prev, next; | |
FT_Int best_segment_first, best_segment_last; | |
FT_Int best_on_point_first, best_on_point_last; | |
FT_Pos dist; | |
best_segment_first = best_point; | |
best_segment_last = best_point; | |
if ( FT_CURVE_TAG( outline.tags[best_point] ) == FT_CURVE_TAG_ON ) | |
{ | |
best_on_point_first = best_point; | |
best_on_point_last = best_point; | |
} | |
else | |
{ | |
best_on_point_first = -1; | |
best_on_point_last = -1; | |
} | |
/* look for the previous and next points on the contour */ | |
/* that are not on the same Y coordinate, then threshold */ | |
/* the `closeness'... */ | |
prev = best_point; | |
next = prev; | |
do | |
{ | |
if ( prev > best_contour_first ) | |
prev--; | |
else | |
prev = best_contour_last; | |
dist = FT_ABS( points[prev].y - best_y ); | |
/* accept a small distance or a small angle (both values are */ | |
/* heuristic; value 20 corresponds to approx. 2.9 degrees) */ | |
if ( dist > 5 ) | |
if ( FT_ABS( points[prev].x - best_x ) <= 20 * dist ) | |
break; | |
best_segment_first = prev; | |
if ( FT_CURVE_TAG( outline.tags[prev] ) == FT_CURVE_TAG_ON ) | |
{ | |
best_on_point_first = prev; | |
if ( best_on_point_last < 0 ) | |
best_on_point_last = prev; | |
} | |
} while ( prev != best_point ); | |
do | |
{ | |
if ( next < best_contour_last ) | |
next++; | |
else | |
next = best_contour_first; | |
dist = FT_ABS( points[next].y - best_y ); | |
if ( dist > 5 ) | |
if ( FT_ABS( points[next].x - best_x ) <= 20 * dist ) | |
break; | |
best_segment_last = next; | |
if ( FT_CURVE_TAG( outline.tags[next] ) == FT_CURVE_TAG_ON ) | |
{ | |
best_on_point_last = next; | |
if ( best_on_point_first < 0 ) | |
best_on_point_first = next; | |
} | |
} while ( next != best_point ); | |
if ( AF_LATIN_IS_LONG_BLUE( bs ) ) | |
{ | |
/* If this flag is set, we have an additional constraint to */ | |
/* get the blue zone distance: Find a segment of the topmost */ | |
/* (or bottommost) contour that is longer than a heuristic */ | |
/* threshold. This ensures that small bumps in the outline */ | |
/* are ignored (for example, the `vertical serifs' found in */ | |
/* many Hebrew glyph designs). */ | |
/* If this segment is long enough, we are done. Otherwise, */ | |
/* search the segment next to the extremum that is long */ | |
/* enough, has the same direction, and a not too large */ | |
/* vertical distance from the extremum. Note that the */ | |
/* algorithm doesn't check whether the found segment is */ | |
/* actually the one (vertically) nearest to the extremum. */ | |
/* heuristic threshold value */ | |
FT_Pos length_threshold = metrics->units_per_em / 25; | |
dist = FT_ABS( points[best_segment_last].x - | |
points[best_segment_first].x ); | |
if ( dist < length_threshold && | |
best_segment_last - best_segment_first + 2 <= | |
best_contour_last - best_contour_first ) | |
{ | |
/* heuristic threshold value */ | |
FT_Pos height_threshold = metrics->units_per_em / 4; | |
FT_Int first; | |
FT_Int last; | |
FT_Bool hit; | |
/* we intentionally declare these two variables */ | |
/* outside of the loop since various compilers emit */ | |
/* incorrect warning messages otherwise, talking about */ | |
/* `possibly uninitialized variables' */ | |
FT_Int p_first = 0; /* make compiler happy */ | |
FT_Int p_last = 0; | |
FT_Bool left2right; | |
/* compute direction */ | |
prev = best_point; | |
do | |
{ | |
if ( prev > best_contour_first ) | |
prev--; | |
else | |
prev = best_contour_last; | |
if ( points[prev].x != best_x ) | |
break; | |
} while ( prev != best_point ); | |
/* skip glyph for the degenerate case */ | |
if ( prev == best_point ) | |
continue; | |
left2right = FT_BOOL( points[prev].x < points[best_point].x ); | |
first = best_segment_last; | |
last = first; | |
hit = 0; | |
do | |
{ | |
FT_Bool l2r; | |
FT_Pos d; | |
if ( !hit ) | |
{ | |
/* no hit; adjust first point */ | |
first = last; | |
/* also adjust first and last on point */ | |
if ( FT_CURVE_TAG( outline.tags[first] ) == | |
FT_CURVE_TAG_ON ) | |
{ | |
p_first = first; | |
p_last = first; | |
} | |
else | |
{ | |
p_first = -1; | |
p_last = -1; | |
} | |
hit = 1; | |
} | |
if ( last < best_contour_last ) | |
last++; | |
else | |
last = best_contour_first; | |
if ( FT_ABS( best_y - points[first].y ) > height_threshold ) | |
{ | |
/* vertical distance too large */ | |
hit = 0; | |
continue; | |
} | |
/* same test as above */ | |
dist = FT_ABS( points[last].y - points[first].y ); | |
if ( dist > 5 ) | |
if ( FT_ABS( points[last].x - points[first].x ) <= | |
20 * dist ) | |
{ | |
hit = 0; | |
continue; | |
} | |
if ( FT_CURVE_TAG( outline.tags[last] ) == FT_CURVE_TAG_ON ) | |
{ | |
p_last = last; | |
if ( p_first < 0 ) | |
p_first = last; | |
} | |
l2r = FT_BOOL( points[first].x < points[last].x ); | |
d = FT_ABS( points[last].x - points[first].x ); | |
if ( l2r == left2right && | |
d >= length_threshold ) | |
{ | |
/* all constraints are met; update segment after finding */ | |
/* its end */ | |
do | |
{ | |
if ( last < best_contour_last ) | |
last++; | |
else | |
last = best_contour_first; | |
d = FT_ABS( points[last].y - points[first].y ); | |
if ( d > 5 ) | |
if ( FT_ABS( points[next].x - points[first].x ) <= | |
20 * dist ) | |
{ | |
if ( last > best_contour_first ) | |
last--; | |
else | |
last = best_contour_last; | |
break; | |
} | |
p_last = last; | |
if ( FT_CURVE_TAG( outline.tags[last] ) == | |
FT_CURVE_TAG_ON ) | |
{ | |
p_last = last; | |
if ( p_first < 0 ) | |
p_first = last; | |
} | |
} while ( last != best_segment_first ); | |
best_y = points[first].y; | |
best_segment_first = first; | |
best_segment_last = last; | |
best_on_point_first = p_first; | |
best_on_point_last = p_last; | |
break; | |
} | |
} while ( last != best_segment_first ); | |
} | |
} | |
/* for computing blue zones, we add the y offset as returned */ | |
/* by the currently used OpenType feature -- for example, */ | |
/* superscript glyphs might be identical to subscript glyphs */ | |
/* with a vertical shift */ | |
best_y += y_offset; | |
FT_TRACE5(( " U+%04lX: best_y = %5ld", ch, best_y )); | |
/* now set the `round' flag depending on the segment's kind: */ | |
/* */ | |
/* - if the horizontal distance between the first and last */ | |
/* `on' point is larger than a heuristic threshold */ | |
/* we have a flat segment */ | |
/* - if either the first or the last point of the segment is */ | |
/* an `off' point, the segment is round, otherwise it is */ | |
/* flat */ | |
if ( best_on_point_first >= 0 && | |
best_on_point_last >= 0 && | |
( FT_ABS( points[best_on_point_last].x - | |
points[best_on_point_first].x ) ) > | |
flat_threshold ) | |
round = 0; | |
else | |
round = FT_BOOL( | |
FT_CURVE_TAG( outline.tags[best_segment_first] ) != | |
FT_CURVE_TAG_ON || | |
FT_CURVE_TAG( outline.tags[best_segment_last] ) != | |
FT_CURVE_TAG_ON ); | |
if ( round && AF_LATIN_IS_NEUTRAL_BLUE( bs ) ) | |
{ | |
/* only use flat segments for a neutral blue zone */ | |
FT_TRACE5(( " (round, skipped)\n" )); | |
continue; | |
} | |
FT_TRACE5(( " (%s)\n", round ? "round" : "flat" )); | |
} | |
if ( round ) | |
rounds[num_rounds++] = best_y; | |
else | |
flats[num_flats++] = best_y; | |
} | |
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( bs ) ^ over_ref ) | |
{ | |
*blue_ref = | |
*blue_shoot = ( shoot + ref ) / 2; | |
FT_TRACE5(( " [overshoot smaller than reference," | |
" taking mean value]\n" )); | |
} | |
} | |
blue->ascender = ascender; | |
blue->descender = descender; | |
blue->flags = 0; | |
if ( AF_LATIN_IS_TOP_BLUE( bs ) ) | |
blue->flags |= AF_LATIN_BLUE_TOP; | |
if ( AF_LATIN_IS_NEUTRAL_BLUE( bs ) ) | |
blue->flags |= AF_LATIN_BLUE_NEUTRAL; | |
/* | |
* 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 ( AF_LATIN_IS_X_HEIGHT_BLUE( bs ) ) | |
blue->flags |= AF_LATIN_BLUE_ADJUSTMENT; | |
FT_TRACE5(( " -> reference = %ld\n" | |
" overshoot = %ld\n", | |
*blue_ref, *blue_shoot )); | |
} | |
FT_TRACE5(( "\n" )); | |
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_ULong glyph_index; | |
FT_Long y_offset; | |
af_get_char_index( &metrics->root, i, &glyph_index, &y_offset ); | |
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_CharMap oldmap = face->charmap; | |
metrics->units_per_em = face->units_per_EM; | |
if ( !FT_Select_Charmap( face, FT_ENCODING_UNICODE ) ) | |
{ | |
af_latin_metrics_init_widths( metrics, face ); | |
af_latin_metrics_init_blues( metrics, face ); | |
af_latin_metrics_check_digits( metrics, face ); | |
} | |
FT_Set_Charmap( face, oldmap ); | |
return FT_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_Pos threshold; | |
FT_Pos fitted; | |
FT_UInt limit; | |
FT_UInt ppem; | |
scaled = FT_MulFix( blue->shoot.org, scaler->y_scale ); | |
ppem = metrics->root.scaler.face->size->metrics.x_ppem; | |
limit = metrics->root.globals->increase_x_height; | |
threshold = 40; | |
/* if the `increase-x-height' property is active, */ | |
/* we round up much more often */ | |
if ( limit && | |
ppem <= limit && | |
ppem >= AF_PROP_INCREASE_X_HEIGHT_MIN ) | |
threshold = 52; | |
fitted = ( scaled + threshold ) & ~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 ) | |
{ | |
FT_Pos max_height; | |
FT_Pos dist; | |
FT_Fixed new_scale; | |
new_scale = FT_MulDiv( scale, fitted, scaled ); | |
/* the scaling should not change the result by more than two pixels */ | |
max_height = metrics->units_per_em; | |
for ( nn = 0; nn < Axis->blue_count; nn++ ) | |
{ | |
max_height = FT_MAX( max_height, Axis->blues[nn].ascender ); | |
max_height = FT_MAX( max_height, -Axis->blues[nn].descender ); | |
} | |
dist = FT_ABS( FT_MulFix( max_height, new_scale - scale ) ); | |
dist &= ~127; | |
if ( dist == 0 ) | |
{ | |
scale = new_scale; | |
FT_TRACE5(( | |
"af_latin_metrics_scale_dim:" | |
" x height alignment (style `%s'):\n" | |
" " | |
" vertical scaling changed from %.4f to %.4f (by %d%%)\n" | |
"\n", | |
af_style_names[metrics->root.style_class->style], | |
axis->org_scale / 65536.0, | |
scale / 65536.0, | |
( fitted - scaled ) * 100 / scaled )); | |
} | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
else | |
{ | |
FT_TRACE5(( | |
"af_latin_metrics_scale_dim:" | |
" x height alignment (style `%s'):\n" | |
" " | |
" excessive vertical scaling abandoned\n" | |
"\n", | |
af_style_names[metrics->root.style_class->style] )); | |
} | |
#endif | |
} | |
} | |
} | |
} | |
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; | |
} | |
FT_TRACE5(( "%s widths (style `%s')\n", | |
dim == AF_DIMENSION_HORZ ? "horizontal" : "vertical", | |
af_style_names[metrics->root.style_class->style] )); | |
/* 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; | |
FT_TRACE5(( " %d scaled to %.2f\n", | |
width->org, | |
width->cur / 64.0 )); | |
} | |
FT_TRACE5(( "\n" )); | |
/* an extra-light axis corresponds to a standard width that is */ | |
/* smaller than 5/8 pixels */ | |
axis->extra_light = | |
(FT_Bool)( FT_MulFix( axis->standard_width, scale ) < 32 + 8 ); | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
if ( axis->extra_light ) | |
FT_TRACE5(( "`%s' style is extra light (at current resolution)\n" | |
"\n", | |
af_style_names[metrics->root.style_class->style] )); | |
#endif | |
if ( dim == AF_DIMENSION_VERT ) | |
{ | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
if ( axis->blue_count ) | |
FT_TRACE5(( "blue zones (style `%s')\n", | |
af_style_names[metrics->root.style_class->style] )); | |
#endif | |
/* 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 ) | |
{ | |
#if 0 | |
FT_Pos delta1; | |
#endif | |
FT_Pos delta2; | |
/* use discrete values for blue zone widths */ | |
#if 0 | |
/* generic, original code */ | |
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; | |
#else | |
/* simplified version due to abs(dist) <= 48 */ | |
delta2 = dist; | |
if ( dist < 0 ) | |
delta2 = -delta2; | |
if ( delta2 < 32 ) | |
delta2 = 0; | |
else if ( delta2 < 48 ) | |
delta2 = 32; | |
else | |
delta2 = 64; | |
if ( dist < 0 ) | |
delta2 = -delta2; | |
blue->ref.fit = FT_PIX_ROUND( blue->ref.cur ); | |
blue->shoot.fit = blue->ref.fit - delta2; | |
#endif | |
blue->flags |= AF_LATIN_BLUE_ACTIVE; | |
FT_TRACE5(( " reference %d: %d scaled to %.2f%s\n" | |
" overshoot %d: %d scaled to %.2f%s\n", | |
nn, | |
blue->ref.org, | |
blue->ref.fit / 64.0, | |
blue->flags & AF_LATIN_BLUE_ACTIVE ? "" | |
: " (inactive)", | |
nn, | |
blue->shoot.org, | |
blue->shoot.fit / 64.0, | |
blue->flags & AF_LATIN_BLUE_ACTIVE ? "" | |
: " (inactive)" )); | |
} | |
} | |
} | |
} | |
/* 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; | |
metrics->root.scaler.flags = scaler->flags; | |
af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ ); | |
af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT ); | |
} | |
/* Extract standard_width from writing system/script specific */ | |
/* metrics class. */ | |
FT_LOCAL_DEF( void ) | |
af_latin_get_standard_widths( AF_LatinMetrics metrics, | |
FT_Pos* stdHW, | |
FT_Pos* stdVW ) | |
{ | |
if ( stdHW ) | |
*stdHW = metrics->axis[AF_DIMENSION_VERT].standard_width; | |
if ( stdVW ) | |
*stdVW = metrics->axis[AF_DIMENSION_HORZ].standard_width; | |
} | |
/*************************************************************************/ | |
/*************************************************************************/ | |
/***** *****/ | |
/***** 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_LatinMetrics metrics = (AF_LatinMetrics)hints->metrics; | |
AF_AxisHints axis = &hints->axis[dim]; | |
FT_Memory memory = hints->memory; | |
FT_Error error = FT_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_Pos flat_threshold = FLAT_THRESHOLD( metrics->units_per_em ); | |
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_Pos min_on_pos = 32000; | |
FT_Pos max_on_pos = -32000; | |
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; | |
/* get minimum and maximum coordinate of on points */ | |
if ( !( point->flags & AF_FLAG_CONTROL ) ) | |
{ | |
v = point->v; | |
if ( v < min_on_pos ) | |
min_on_pos = v; | |
if ( v > max_on_pos ) | |
max_on_pos = v; | |
} | |
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, and the length of the on points */ | |
/* inbetween doesn't exceed a heuristic limit */ | |
if ( ( segment->first->flags | point->flags ) & AF_FLAG_CONTROL && | |
( max_on_pos - min_on_pos ) < flat_threshold ) | |
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; | |
/* fall through */ | |
} | |
} | |
/* 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; | |
error = af_axis_hints_new_segment( axis, memory, &segment ); | |
if ( error ) | |
goto Exit; | |
/* clear all segment fields */ | |
segment[0] = seg0; | |
segment->dir = (FT_Char)segment_dir; | |
segment->first = point; | |
segment->last = point; | |
min_pos = max_pos = point->u; | |
if ( point->flags & AF_FLAG_CONTROL ) | |
{ | |
min_on_pos = 32000; | |
max_on_pos = -32000; | |
} | |
else | |
min_on_pos = max_on_pos = point->v; | |
on_edge = 1; | |
} | |
point = point->next; | |
} | |
} /* contours */ | |
/* now slightly increase the height of segments if 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_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. If `width_count' and */ | |
/* `widths' are non-zero, use them to fine-tune the scoring function. */ | |
FT_LOCAL_DEF( void ) | |
af_latin_hints_link_segments( AF_GlyphHints hints, | |
FT_UInt width_count, | |
AF_WidthRec* widths, | |
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, dist_score, max_width; | |
AF_Segment seg1, seg2; | |
if ( width_count ) | |
max_width = widths[width_count - 1].org; | |
else | |
max_width = 0; | |
/* a heuristic value to set up a minimum value for overlapping */ | |
len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 ); | |
if ( len_threshold == 0 ) | |
len_threshold = 1; | |
/* a heuristic value to weight lengths */ | |
len_score = AF_LATIN_CONSTANT( hints->metrics, 6000 ); | |
/* a heuristic value to weight distances (no call to */ | |
/* AF_LATIN_CONSTANT needed, since we work on multiples */ | |
/* of the stem width) */ | |
dist_score = 3000; | |
/* now compare each segment to the others */ | |
for ( seg1 = segments; seg1 < segment_limit; seg1++ ) | |
{ | |
if ( seg1->dir != axis->major_dir ) | |
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 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; | |
/* compute maximum coordinate difference of the two segments */ | |
/* (this is, how much they overlap) */ | |
len = max - min; | |
if ( len >= len_threshold ) | |
{ | |
/* | |
* The score is the sum of two demerits indicating the | |
* `badness' of a fit, measured along the segments' main axis | |
* and orthogonal to it, respectively. | |
* | |
* o The less overlapping along the main axis, the worse it | |
* is, causing a larger demerit. | |
* | |
* o The nearer the orthogonal distance to a stem width, the | |
* better it is, causing a smaller demerit. For simplicity, | |
* however, we only increase the demerit for values that | |
* exceed the largest stem width. | |
*/ | |
FT_Pos dist = pos2 - pos1; | |
FT_Pos dist_demerit, score; | |
if ( max_width ) | |
{ | |
/* distance demerits are based on multiples of `max_width'; */ | |
/* we scale by 1024 for getting more precision */ | |
FT_Pos delta = ( dist << 10 ) / max_width - ( 1 << 10 ); | |
if ( delta > 10000 ) | |
dist_demerit = 32000; | |
else if ( delta > 0 ) | |
dist_demerit = delta * delta / dist_score; | |
else | |
dist_demerit = 0; | |
} | |
else | |
dist_demerit = dist; /* default if no widths available */ | |
score = dist_demerit + len_score / len; | |
/* and we search for the smallest score */ | |
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 = FT_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; | |
#if 0 | |
AF_Direction up_dir; | |
#endif | |
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; | |
#if 0 | |
up_dir = ( dim == AF_DIMENSION_HORZ ) ? AF_DIR_UP | |
: AF_DIR_RIGHT; | |
#endif | |
/* | |
* 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 most 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 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 = NULL; | |
} | |
} | |
Exit: | |
return error; | |
} | |
/* Detect segments and edges for given dimension. */ | |
FT_LOCAL_DEF( FT_Error ) | |
af_latin_hints_detect_features( AF_GlyphHints hints, | |
FT_UInt width_count, | |
AF_WidthRec* widths, | |
AF_Dimension dim ) | |
{ | |
FT_Error error; | |
error = af_latin_hints_compute_segments( hints, dim ); | |
if ( !error ) | |
{ | |
af_latin_hints_link_segments( hints, width_count, widths, dim ); | |
error = af_latin_hints_compute_edges( hints, dim ); | |
} | |
return error; | |
} | |
/* Compute all edges which lie within blue zones. */ | |
static 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_UInt bb; | |
AF_Width best_blue = NULL; | |
FT_Bool best_blue_is_neutral = 0; | |
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 < latin->blue_count; bb++ ) | |
{ | |
AF_LatinBlue blue = latin->blues + bb; | |
FT_Bool is_top_blue, is_neutral_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 (against the major */ | |
/* direction); if it is a bottom zone, check for left edges (in */ | |
/* the major direction) -- this assumes the TrueType convention */ | |
/* for the orientation of contours */ | |
is_top_blue = | |
(FT_Byte)( ( blue->flags & AF_LATIN_BLUE_TOP ) != 0 ); | |
is_neutral_blue = | |
(FT_Byte)( ( blue->flags & AF_LATIN_BLUE_NEUTRAL ) != 0); | |
is_major_dir = | |
FT_BOOL( edge->dir == axis->major_dir ); | |
/* neutral blue zones are handled for both directions */ | |
if ( is_top_blue ^ is_major_dir || is_neutral_blue ) | |
{ | |
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; | |
best_blue_is_neutral = is_neutral_blue; | |
} | |
/* 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 (provided we don't have a */ | |
/* neutral blue zone) */ | |
if ( edge->flags & AF_EDGE_ROUND && | |
dist != 0 && | |
!is_neutral_blue ) | |
{ | |
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; | |
best_blue_is_neutral = is_neutral_blue; | |
} | |
} | |
} | |
} | |
} | |
if ( best_blue ) | |
{ | |
edge->blue_edge = best_blue; | |
if ( best_blue_is_neutral ) | |
edge->flags |= AF_EDGE_NEUTRAL; | |
} | |
} | |
} | |
/* 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_StyleMetrics)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. | |
* | |
* However, if warping is enabled (which only works in `light' hinting | |
* mode), advance widths get adjusted, too. | |
*/ | |
if ( mode == FT_RENDER_MODE_LIGHT || | |
( face->style_flags & FT_STYLE_FLAG_ITALIC ) != 0 ) | |
scaler_flags |= AF_SCALER_FLAG_NO_HORIZONTAL; | |
#ifdef AF_CONFIG_OPTION_USE_WARPER | |
/* get (global) warper flag */ | |
if ( !metrics->root.globals->module->warping ) | |
scaler_flags |= AF_SCALER_FLAG_NO_WARPER; | |
#endif | |
hints->scaler_flags = scaler_flags; | |
hints->other_flags = other_flags; | |
return FT_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_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, 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, | |
FT_UInt base_flags, | |
FT_UInt 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, | |
base_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. */ | |
static 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; | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
FT_UInt num_actions = 0; | |
#endif | |
FT_TRACE5(( "latin %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 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; /* these edges form the stem to check */ | |
if ( edge->flags & AF_EDGE_DONE ) | |
continue; | |
edge1 = NULL; | |
edge2 = edge->link; | |
/* | |
* If a stem contains both a neutral and a non-neutral blue zone, | |
* skip the neutral one. Otherwise, outlines with different | |
* directions might be incorrectly aligned at the same vertical | |
* position. | |
* | |
* If we have two neutral blue zones, skip one of them. | |
* | |
*/ | |
if ( edge->blue_edge && edge2 && edge2->blue_edge ) | |
{ | |
FT_Byte neutral = edge->flags & AF_EDGE_NEUTRAL; | |
FT_Byte neutral2 = edge2->flags & AF_EDGE_NEUTRAL; | |
if ( neutral2 ) | |
{ | |
edge2->blue_edge = NULL; | |
edge2->flags &= ~AF_EDGE_NEUTRAL; | |
} | |
else if ( neutral ) | |
{ | |
edge->blue_edge = NULL; | |
edge->flags &= ~AF_EDGE_NEUTRAL; | |
} | |
} | |
blue = edge->blue_edge; | |
if ( blue ) | |
edge1 = edge; | |
/* flip edges if the other edge is aligned to a blue zone */ | |
else if ( edge2 && edge2->blue_edge ) | |
{ | |
blue = edge2->blue_edge; | |
edge1 = edge2; | |
edge2 = edge; | |
} | |
if ( !edge1 ) | |
continue; | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
if ( !anchor ) | |
FT_TRACE5(( " BLUE_ANCHOR: edge %d (opos=%.2f) snapped to %.2f," | |
" was %.2f (anchor=edge %d)\n", | |
edge1 - edges, edge1->opos / 64.0, blue->fit / 64.0, | |
edge1->pos / 64.0, edge - edges )); | |
else | |
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 )); | |
num_actions++; | |
#endif | |
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; | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
num_actions++; | |
#endif | |
} | |
if ( !anchor ) | |
anchor = edge; | |
} | |
} | |
/* now we align all other 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; | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
num_actions++; | |
#endif | |
continue; | |
} | |
if ( !anchor ) | |
{ | |
/* if we reach this if clause, no stem has been aligned yet */ | |
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, | |
edge->flags, | |
edge2->flags ); | |
/* some voodoo to specially round edges for small stem widths; */ | |
/* the idea is to align the center of a stem, then shifting */ | |
/* the stem edges to suitable positions */ | |
if ( cur_len <= 64 ) | |
{ | |
/* width <= 1px */ | |
u_off = 32; | |
d_off = 32; | |
} | |
else | |
{ | |
/* 1px < width < 1.5px */ | |
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 ); | |
anchor = edge; | |
edge->flags |= AF_EDGE_DONE; | |
FT_TRACE5(( " ANCHOR: edge %d (opos=%.2f) and %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 )); | |
af_latin_align_linked_edge( hints, dim, edge, edge2 ); | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
num_actions += 2; | |
#endif | |
} | |
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, | |
edge->flags, | |
edge2->flags ); | |
if ( edge2->flags & AF_EDGE_DONE ) | |
{ | |
FT_TRACE5(( " ADJUST: edge %d (pos=%.2f) moved to %.2f\n", | |
edge - edges, edge->pos / 64.0, | |
( edge2->pos - cur_len ) / 64.0 )); | |
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: edge %d (opos=%.2f) linked 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, | |
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: edge %d (opos=%.2f) linked 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 )); | |
} | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
num_actions++; | |
#endif | |
edge->flags |= AF_EDGE_DONE; | |
edge2->flags |= AF_EDGE_DONE; | |
if ( edge > edges && edge->pos < edge[-1].pos ) | |
{ | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
FT_TRACE5(( " BOUND: edge %d (pos=%.2f) moved to %.2f\n", | |
edge - edges, edge->pos / 64.0, edge[-1].pos / 64.0 )); | |
num_actions++; | |
#endif | |
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 ) | |
{ | |
edge->pos = FT_PIX_ROUND( edge->opos ); | |
anchor = edge; | |
FT_TRACE5(( " SERIF_ANCHOR: edge %d (opos=%.2f)" | |
" snapped to %.2f\n", | |
edge-edges, edge->opos / 64.0, edge->pos / 64.0 )); | |
} | |
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 )); | |
} | |
} | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
num_actions++; | |
#endif | |
edge->flags |= AF_EDGE_DONE; | |
if ( edge > edges && edge->pos < edge[-1].pos ) | |
{ | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
FT_TRACE5(( " BOUND: edge %d (pos=%.2f) moved to %.2f\n", | |
edge - edges, edge->pos / 64.0, edge[-1].pos / 64.0 )); | |
num_actions++; | |
#endif | |
edge->pos = edge[-1].pos; | |
} | |
if ( edge + 1 < edge_limit && | |
edge[1].flags & AF_EDGE_DONE && | |
edge->pos > edge[1].pos ) | |
{ | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
FT_TRACE5(( " BOUND: edge %d (pos=%.2f) moved to %.2f\n", | |
edge - edges, edge->pos / 64.0, edge[1].pos / 64.0 )); | |
num_actions++; | |
#endif | |
edge->pos = edge[1].pos; | |
} | |
} | |
} | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
if ( !num_actions ) | |
FT_TRACE5(( " (none)\n" )); | |
FT_TRACE5(( "\n" )); | |
#endif | |
} | |
/* Apply the complete hinting algorithm to a latin glyph. */ | |
static FT_Error | |
af_latin_hints_apply( FT_UInt glyph_index, | |
AF_GlyphHints hints, | |
FT_Outline* outline, | |
AF_LatinMetrics metrics ) | |
{ | |
FT_Error error; | |
int dim; | |
AF_LatinAxis axis; | |
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_WARP( hints ) ) || | |
AF_HINTS_DO_HORIZONTAL( hints ) ) | |
#else | |
if ( AF_HINTS_DO_HORIZONTAL( hints ) ) | |
#endif | |
{ | |
axis = &metrics->axis[AF_DIMENSION_HORZ]; | |
error = af_latin_hints_detect_features( hints, | |
axis->width_count, | |
axis->widths, | |
AF_DIMENSION_HORZ ); | |
if ( error ) | |
goto Exit; | |
} | |
if ( AF_HINTS_DO_VERTICAL( hints ) ) | |
{ | |
axis = &metrics->axis[AF_DIMENSION_VERT]; | |
error = af_latin_hints_detect_features( hints, | |
axis->width_count, | |
axis->widths, | |
AF_DIMENSION_VERT ); | |
if ( error ) | |
goto Exit; | |
/* apply blue zones to base characters only */ | |
if ( !( metrics->root.globals->glyph_styles[glyph_index] & AF_NONBASE ) ) | |
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_HINTS_DO_WARP( hints ) ) | |
{ | |
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 /* AF_CONFIG_OPTION_USE_WARPER */ | |
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 *****/ | |
/***** *****/ | |
/*************************************************************************/ | |
/*************************************************************************/ | |
AF_DEFINE_WRITING_SYSTEM_CLASS( | |
af_latin_writing_system_class, | |
AF_WRITING_SYSTEM_LATIN, | |
sizeof ( AF_LatinMetricsRec ), | |
(AF_WritingSystem_InitMetricsFunc) af_latin_metrics_init, | |
(AF_WritingSystem_ScaleMetricsFunc)af_latin_metrics_scale, | |
(AF_WritingSystem_DoneMetricsFunc) NULL, | |
(AF_WritingSystem_GetStdWidthsFunc)af_latin_get_standard_widths, | |
(AF_WritingSystem_InitHintsFunc) af_latin_hints_init, | |
(AF_WritingSystem_ApplyHintsFunc) af_latin_hints_apply | |
) | |
/* END */ |