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kc3-lang/freetype/src/autofit/aflatin2.c
Werner Lemberg
- src/autofit/aflatin2.c
-
/* ATTENTION: This file doesn't compile. It is only here as a reference */ /* of an alternative latin hinting algorithm that was always */ /* marked as experimental. */ /**************************************************************************** * * aflatin2.c * * Auto-fitter hinting routines for latin writing system (body). * * Copyright (C) 2003-2020 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 <freetype/ftadvanc.h> #ifdef FT_OPTION_AUTOFIT2 #include "afglobal.h" #include "aflatin.h" #include "aflatin2.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 aflatin2 FT_LOCAL_DEF( FT_Error ) af_latin2_hints_compute_segments( AF_GlyphHints hints, AF_Dimension dim ); FT_LOCAL_DEF( void ) af_latin2_hints_link_segments( AF_GlyphHints hints, AF_Dimension dim ); /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** L A T I N G L O B A L M E T R I C S *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ FT_LOCAL_DEF( void ) af_latin2_metrics_init_widths( AF_LatinMetrics metrics, FT_Face face ) { /* 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, metrics->root.style_class->standard_char ); if ( glyph_index == 0 ) goto Exit; error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); if ( error || face->glyph->outline.n_points <= 0 ) goto Exit; FT_ZERO( dummy ); dummy->units_per_em = metrics->units_per_em; scaler->x_scale = scaler->y_scale = 0x10000L; scaler->x_delta = scaler->y_delta = 0; scaler->face = face; scaler->render_mode = FT_RENDER_MODE_NORMAL; scaler->flags = 0; af_glyph_hints_rescale( hints, (AF_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_latin2_hints_compute_segments( hints, (AF_Dimension)dim ); if ( error ) goto Exit; af_latin2_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_latin2_blue_chars[AF_LATIN_MAX_BLUES] [AF_LATIN_MAX_TEST_CHARACTERS+1] = { "THEZOCQS", "HEZLOCUS", "fijkdbh", "xzroesc", "xzroesc", "pqgjy" }; static void af_latin2_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_latin2_blue_chars[blues]' string, then compute its top-most or */ /* bottom-most points (depending on `AF_IS_TOP_BLUE') */ FT_TRACE5(( "blue zones computation\n" "======================\n\n" )); for ( bb = 0; bb < AF_LATIN_BLUE_MAX; bb++ ) { const char* p = af_latin2_blue_chars[bb]; const char* limit = p + AF_LATIN_MAX_TEST_CHARACTERS; FT_Pos* blue_ref; FT_Pos* blue_shoot; FT_TRACE5(( "blue zone %d:\n", bb )); num_flats = 0; num_rounds = 0; for ( ; p < limit && *p; p++ ) { FT_UInt glyph_index; FT_Int best_point, best_y, best_first, best_last; FT_Vector* points; FT_Bool round; /* 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(( " %c %d", *p, 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_Pos best_x = points[best_point].x; FT_Int start, end, prev, next; FT_Pos dist; /* now look for the previous and next points that are not on the */ /* same Y coordinate. Threshold the `closeness'... */ start = end = best_point; do { prev = start - 1; if ( prev < best_first ) prev = best_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; start = prev; } while ( start != best_point ); do { next = end + 1; if ( next > best_last ) next = best_first; dist = FT_ABS( points[next].y - best_y ); if ( dist > 5 ) if ( FT_ABS( points[next].x - best_x ) <= 20 * dist ) break; end = next; } while ( end != best_point ); /* now, set the `round' flag depending on the segment's kind */ round = FT_BOOL( FT_CURVE_TAG( glyph->outline.tags[start] ) != FT_CURVE_TAG_ON || FT_CURVE_TAG( glyph->outline.tags[ end ] ) != FT_CURVE_TAG_ON ); 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( bb ) ^ over_ref ) { *blue_ref = *blue_shoot = ( shoot + ref ) / 2; FT_TRACE5(( " [overshoot smaller than reference," " taking mean value]\n" )); } } 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 ( AF_LATIN_IS_X_HEIGHT_BLUE( bb ) ) blue->flags |= AF_LATIN_BLUE_ADJUSTMENT; FT_TRACE5(( " -> reference = %ld\n" " overshoot = %ld\n", *blue_ref, *blue_shoot )); } return; } FT_LOCAL_DEF( void ) af_latin2_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; /* check whether all ASCII digits have the same advance width; */ /* 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; } FT_LOCAL_DEF( FT_Error ) af_latin2_metrics_init( AF_LatinMetrics metrics, FT_Face face ) { FT_Error error = FT_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 ) { af_latin2_metrics_init_widths( metrics, face ); af_latin2_metrics_init_blues( metrics, face ); af_latin2_metrics_check_digits( metrics, face ); } FT_Set_Charmap( face, oldmap ); return FT_Err_Ok; } static void af_latin2_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 Y scale to optimize the alignment of the top of small * letters to the pixel grid */ if ( dim == AF_DIMENSION_VERT ) { AF_LatinAxis vaxis = &metrics->axis[AF_DIMENSION_VERT]; AF_LatinBlue blue = NULL; for ( nn = 0; nn < vaxis->blue_count; nn++ ) { if ( vaxis->blues[nn].flags & AF_LATIN_BLUE_ADJUSTMENT ) { blue = &vaxis->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 1 if ( scaled != fitted ) { scale = FT_MulDiv( scale, fitted, scaled ); FT_TRACE5(( "== scaled x-top = %.2g" " fitted = %.2g, scaling = %.4g\n", scaled / 64.0, fitted / 64.0, ( fitted * 1.0 ) / scaled )); } #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; } /* scale the standard 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 5/8 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; FT_TRACE5(( ">> activating blue zone %d:" " ref.cur=%.2g ref.fit=%.2g" " shoot.cur=%.2g shoot.fit=%.2g\n", nn, blue->ref.cur / 64.0, blue->ref.fit / 64.0, blue->shoot.cur / 64.0, blue->shoot.fit / 64.0 )); blue->flags |= AF_LATIN_BLUE_ACTIVE; } } } } FT_LOCAL_DEF( void ) af_latin2_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_latin2_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ ); af_latin2_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT ); } /* Extract standard_width from writing system/script specific */ /* metrics class. */ FT_LOCAL_DEF( void ) af_latin2_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 *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ #define SORT_SEGMENTS FT_LOCAL_DEF( FT_Error ) af_latin2_hints_compute_segments( AF_GlyphHints hints, AF_Dimension dim ) { 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_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 start = point; AF_Point last = point->prev; if ( point == last ) /* skip singletons -- just in case */ continue; /* already on an edge ?, backtrack to find its start */ if ( FT_ABS( point->in_dir ) == major_dir ) { point = point->prev; while ( point->in_dir == start->in_dir ) point = point->prev; } else /* otherwise, find first segment start, if any */ { while ( FT_ABS( point->out_dir ) != major_dir ) { point = point->next; if ( point == start ) goto NextContour; } } start = point; for (;;) { AF_Point first; FT_Pos min_u, min_v, max_u, max_v; /* we're at the start of a new segment */ FT_ASSERT( FT_ABS( point->out_dir ) == major_dir && point->in_dir != point->out_dir ); first = point; min_u = max_u = point->u; min_v = max_v = point->v; point = point->next; while ( point->out_dir == first->out_dir ) { point = point->next; if ( point->u < min_u ) min_u = point->u; if ( point->u > max_u ) max_u = point->u; } if ( point->v < min_v ) min_v = point->v; if ( point->v > max_v ) max_v = point->v; /* record new segment */ error = af_axis_hints_new_segment( axis, memory, &segment ); if ( error ) goto Exit; segment[0] = seg0; segment->dir = first->out_dir; segment->first = first; segment->last = point; segment->pos = (FT_Short)( ( min_u + max_u ) >> 1 ); segment->min_coord = (FT_Short) min_v; segment->max_coord = (FT_Short) max_v; segment->height = (FT_Short)( max_v - min_v ); /* a segment is round if it doesn't have successive */ /* on-curve points. */ { AF_Point pt = first; AF_Point last = point; FT_UInt f0 = pt->flags & AF_FLAG_CONTROL; FT_UInt f1; segment->flags &= ~AF_EDGE_ROUND; for ( ; pt != last; f0 = f1 ) { pt = pt->next; f1 = pt->flags & AF_FLAG_CONTROL; if ( !f0 && !f1 ) break; if ( pt == last ) segment->flags |= AF_EDGE_ROUND; } } /* this can happen in the case of a degenerate contour * e.g. a 2-point vertical contour */ if ( point == start ) break; /* jump to the start of the next segment, if any */ while ( FT_ABS( point->out_dir ) != major_dir ) { point = point->next; if ( point == start ) goto NextContour; } } NextContour: ; } /* 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; AF_Point p; FT_Pos first_v = first->v; FT_Pos last_v = last->v; if ( first_v < last_v ) { 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 { 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 ) ); } } } #ifdef AF_SORT_SEGMENTS /* place all segments with a negative direction to the start * of the array, used to speed up segment linking later... */ { AF_Segment segments = axis->segments; FT_UInt count = axis->num_segments; FT_UInt ii, jj; for ( ii = 0; ii < count; ii++ ) { if ( segments[ii].dir > 0 ) { for ( jj = ii + 1; jj < count; jj++ ) { if ( segments[jj].dir < 0 ) { AF_SegmentRec tmp; tmp = segments[ii]; segments[ii] = segments[jj]; segments[jj] = tmp; break; } } if ( jj == count ) break; } } axis->mid_segments = ii; } #endif Exit: return error; } FT_LOCAL_DEF( void ) af_latin2_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; #ifdef AF_SORT_SEGMENTS AF_Segment segment_mid = segments + axis->mid_segments; #endif 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 ); #ifdef AF_SORT_SEGMENTS for ( seg1 = segments; seg1 < segment_mid; seg1++ ) { if ( seg1->dir != axis->major_dir ) continue; for ( seg2 = segment_mid; seg2 < segment_limit; seg2++ ) #else /* now compare each segment to the others */ for ( seg1 = segments; seg1 < segment_limit; seg1++ ) { if ( seg1->dir != axis->major_dir ) continue; for ( seg2 = segments; seg2 < segment_limit; seg2++ ) if ( seg1->dir + seg2->dir == 0 && seg2->pos > seg1->pos ) #endif { FT_Pos pos1 = seg1->pos; FT_Pos pos2 = seg2->pos; FT_Pos dist = pos2 - pos1; if ( dist < 0 ) continue; { 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; len = max - min; if ( len >= len_threshold ) { score = dist + len_score / len; if ( score < seg1->score ) { seg1->score = score; seg1->link = seg2; } if ( score < seg2->score ) { seg2->score = score; seg2->link = seg1; } } } } } #if 0 } #endif /* now, compute the `serif' segments */ for ( seg1 = segments; seg1 < segment_limit; seg1++ ) { seg2 = seg1->link; if ( seg2 ) { if ( seg2->link != seg1 ) { seg1->link = NULL; seg1->serif = seg2->link; } } } } FT_LOCAL_DEF( FT_Error ) af_latin2_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; 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 want to ignore very small (mostly serif) segments, we do that * by ignoring those that whose length is less than a given fraction * of the standard width. If there is no standard width, we ignore * those that are less than a given size in pixels * * also, unlink serif segments that are linked to segments farther * than 50% of the standard width */ if ( dim == AF_DIMENSION_HORZ ) { if ( laxis->width_count > 0 ) segment_length_threshold = ( laxis->standard_width * 10 ) >> 4; else segment_length_threshold = FT_DivFix( 64, hints->y_scale ); } else segment_length_threshold = 0; /********************************************************************** * * We will 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 will be processed in the second step to compute the * edge's properties. * * Note that the edges table is sorted along the segment/edge * position. * */ edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold, scale ); if ( edge_distance_threshold > 64 / 4 ) edge_distance_threshold = 64 / 4; edge_distance_threshold = FT_DivFix( edge_distance_threshold, scale ); 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 ) { FT_Pos dist = seg->serif->pos - seg->pos; if ( dist < 0 ) dist = -dist; if ( dist >= laxis->standard_width >> 1 ) { /* unlink this serif, it is too distant from its reference stem */ seg->serif = NULL; } else if ( 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, seg->dir, 0, memory, &edge ); if ( error ) goto Exit; /* add the segment to the new edge's list */ FT_ZERO( edge ); edge->first = seg; edge->last = seg; edge->dir = seg->dir; edge->fpos = seg->pos; edge->opos = FT_MulFix( seg->pos, scale ); edge->pos = edge->opos; seg->edge_next = seg; } else { /* if an edge was found, simply add the segment to the edge's */ /* list */ seg->edge_next = found->first; found->last->edge_next = seg; found->last = seg; } } /********************************************************************** * * Good, we will now compute each edge's properties according to * segments found on its position. Basically, these are: * * - 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 ) || 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 /* gets 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; } FT_LOCAL_DEF( FT_Error ) af_latin2_hints_detect_features( AF_GlyphHints hints, AF_Dimension dim ) { FT_Error error; error = af_latin2_hints_compute_segments( hints, dim ); if ( !error ) { af_latin2_hints_link_segments( hints, dim ); error = af_latin2_hints_compute_edges( hints, dim ); } return error; } static void af_latin2_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; FT_Pos best_dist0; /* initial threshold */ /* compute the initial threshold as a fraction of the EM size */ best_dist0 = FT_MulFix( metrics->units_per_em / 40, scale ); if ( best_dist0 > 64 / 2 ) best_dist0 = 64 / 2; /* 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 = best_dist0; 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 small) */ 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; AF_Width compare; /* if it's a rounded edge, compare it to the overshoot position */ /* if it's a flat edge, compare it to the reference position */ if ( edge->flags & AF_EDGE_ROUND ) compare = &blue->shoot; else compare = &blue->ref; dist = edge->fpos - compare->org; if ( dist < 0 ) dist = -dist; dist = FT_MulFix( dist, scale ); if ( dist < best_dist ) { best_dist = dist; best_blue = compare; } #if 0 /* now, compare it to the overshoot position if the edge is */ /* rounded, and if 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 ) { blue = latin->blues + bb; 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; } } } #endif } } if ( best_blue ) edge->blue_edge = best_blue; } } static FT_Error af_latin2_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 `af_latin2_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 unless in `light' or `lcd' mode. */ if ( mode != FT_RENDER_MODE_LIGHT && mode != FT_RENDER_MODE_LCD ) other_flags |= AF_LATIN_HINTS_STEM_ADJUST; if ( mode == FT_RENDER_MODE_MONO ) other_flags |= AF_LATIN_HINTS_MONO; /* * In `light' or `lcd' mode we disable horizontal hinting completely. * We also do it if the face is italic. */ if ( mode == FT_RENDER_MODE_LIGHT || mode == FT_RENDER_MODE_LCD || ( 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 0; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** 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_latin2_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 */ static FT_Pos af_latin2_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 ); FT_UNUSED( base_flags ); 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; #if 0 else if ( ( base_flags & AF_EDGE_ROUND ) ) { if ( dist < 80 ) dist = 64; } else if ( dist < 56 ) dist = 56; #endif if ( axis->width_count > 0 ) { FT_Pos delta; /* compare to standard width */ if ( axis->width_count > 0 ) { 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_latin2_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_Int 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_latin2_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_latin2_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 )); } static void af_latin2_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 ****/ /**** ****/ /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ static void af_latin2_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; AF_Edge edge; AF_Edge anchor = NULL; FT_Int has_serifs = 0; FT_Pos anchor_drift = 0; FT_TRACE5(( "==== hinting %s edges =====\n", dim == AF_DIMENSION_HORZ ? "vertical" : "horizontal" )); /* 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_latin2_align_linked_edge( hints, dim, edge1, edge2 ); edge2->flags |= AF_EDGE_DONE; } if ( !anchor ) { anchor = edge; anchor_drift = ( anchor->pos - anchor->opos ); if ( edge2 ) anchor_drift = ( anchor_drift + ( edge2->pos - edge2->opos ) ) >> 1; } } } /* now we will 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_latin2_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_latin2_compute_stem_width( hints, dim, org_len, edge->flags, edge2->flags ); if ( cur_len <= 64 ) u_off = 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_latin2_align_linked_edge( hints, dim, edge, edge2 ); edge2->flags |= AF_EDGE_DONE; anchor_drift = ( ( anchor->pos - anchor->opos ) + ( edge2->pos - edge2->opos ) ) >> 1; FT_TRACE5(( "DRIFT: %.2f\n", anchor_drift/64.0 )); } else { FT_Pos org_pos, org_len, org_center, cur_center, cur_len; FT_Pos org_left, org_right; org_pos = edge->opos + anchor_drift; org_len = edge2->opos - edge->opos; org_center = org_pos + ( org_len >> 1 ); cur_len = af_latin2_compute_stem_width( hints, dim, org_len, edge->flags, edge2->flags ); org_left = org_pos + ( ( org_len - cur_len ) >> 1 ); org_right = org_pos + ( ( org_len + cur_len ) >> 1 ); FT_TRACE5(( "ALIGN: left=%.2f right=%.2f ", org_left / 64.0, org_right / 64.0 )); cur_center = org_center; if ( edge2->flags & AF_EDGE_DONE ) { FT_TRACE5(( "\n" )); edge->pos = edge2->pos - cur_len; } else { /* we want to compare several displacement, and choose * the one that increases fitness while minimizing * distortion as well */ FT_Pos displacements[6], scores[6], org, fit, delta; FT_UInt count = 0; /* note: don't even try to fit tiny stems */ if ( cur_len < 32 ) { FT_TRACE5(( "tiny stem\n" )); goto AlignStem; } /* if the span is within a single pixel, don't touch it */ if ( FT_PIX_FLOOR( org_left ) == FT_PIX_CEIL( org_right ) ) { FT_TRACE5(( "single pixel stem\n" )); goto AlignStem; } if ( cur_len <= 96 ) { /* we want to avoid the absolute worst case which is * when the left and right edges of the span each represent * about 50% of the gray. we'd better want to change this * to 25/75%, since this is much more pleasant to the eye with * very acceptable distortion */ FT_Pos frac_left = org_left & 63; FT_Pos frac_right = org_right & 63; if ( frac_left >= 22 && frac_left <= 42 && frac_right >= 22 && frac_right <= 42 ) { org = frac_left; fit = ( org <= 32 ) ? 16 : 48; delta = FT_ABS( fit - org ); displacements[count] = fit - org; scores[count++] = delta; FT_TRACE5(( "dispA=%.2f (%d) ", ( fit - org ) / 64.0, delta )); org = frac_right; fit = ( org <= 32 ) ? 16 : 48; delta = FT_ABS( fit - org ); displacements[count] = fit - org; scores[count++] = delta; FT_TRACE5(( "dispB=%.2f (%d) ", ( fit - org ) / 64.0, delta )); } } /* snapping the left edge to the grid */ org = org_left; fit = FT_PIX_ROUND( org ); delta = FT_ABS( fit - org ); displacements[count] = fit - org; scores[count++] = delta; FT_TRACE5(( "dispC=%.2f (%d) ", ( fit - org ) / 64.0, delta )); /* snapping the right edge to the grid */ org = org_right; fit = FT_PIX_ROUND( org ); delta = FT_ABS( fit - org ); displacements[count] = fit - org; scores[count++] = delta; FT_TRACE5(( "dispD=%.2f (%d) ", ( fit - org ) / 64.0, delta )); /* now find the best displacement */ { FT_Pos best_score = scores[0]; FT_Pos best_disp = displacements[0]; FT_UInt nn; for ( nn = 1; nn < count; nn++ ) { if ( scores[nn] < best_score ) { best_score = scores[nn]; best_disp = displacements[nn]; } } cur_center = org_center + best_disp; } FT_TRACE5(( "\n" )); } AlignStem: edge->pos = cur_center - ( cur_len >> 1 ); edge2->pos = edge->pos + cur_len; FT_TRACE5(( "STEM1: %d (opos=%.2f) to %d (opos=%.2f)" " snapped to (%.2f) and (%.2f)," " org_len=%.2f cur_len=%.2f\n", edge-edges, edge->opos / 64.0, edge2-edges, edge2->opos / 64.0, edge->pos / 64.0, edge2->pos / 64.0, org_len / 64.0, cur_len / 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. */ #if 0 { FT_Int 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; } } } #endif 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_latin2_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; } } } static FT_Error af_latin2_hints_apply( FT_UInt glyph_index, AF_GlyphHints hints, FT_Outline* outline, AF_LatinMetrics metrics ) { FT_Error error; int dim; FT_UNUSED( glyph_index ); error = af_glyph_hints_reload( hints, outline ); if ( error ) goto Exit; /* analyze glyph outline */ if ( AF_HINTS_DO_HORIZONTAL( hints ) ) { error = af_latin2_hints_detect_features( hints, AF_DIMENSION_HORZ ); if ( error ) goto Exit; } if ( AF_HINTS_DO_VERTICAL( hints ) ) { error = af_latin2_hints_detect_features( hints, AF_DIMENSION_VERT ); if ( error ) goto Exit; af_latin2_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_NORMAL && AF_HINTS_DO_WARP( hints ) ) { AF_WarperRec warper; FT_Fixed scale; FT_Pos delta; af_warper_compute( &warper, hints, dim, &scale, &delta ); af_glyph_hints_scale_dim( hints, dim, scale, delta ); continue; } #endif /* AF_CONFIG_OPTION_USE_WARPER */ if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) || ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) ) ) { af_latin2_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_latin2_writing_system_class, AF_WRITING_SYSTEM_LATIN2, sizeof ( AF_LatinMetricsRec ), (AF_WritingSystem_InitMetricsFunc) af_latin2_metrics_init, /* style_metrics_init */ (AF_WritingSystem_ScaleMetricsFunc)af_latin2_metrics_scale, /* style_metrics_scale */ (AF_WritingSystem_DoneMetricsFunc) NULL, /* style_metrics_done */ (AF_WritingSystem_GetStdWidthsFunc)af_latin2_get_standard_widths, /* style_metrics_getstdw */ (AF_WritingSystem_InitHintsFunc) af_latin2_hints_init, /* style_hints_init */ (AF_WritingSystem_ApplyHintsFunc) af_latin2_hints_apply /* style_hints_apply */ ) #else /* !FT_OPTION_AUTOFIT2 */ /* ANSI C doesn't like empty source files */ typedef int _af_latin2_dummy; #endif /* !FT_OPTION_AUTOFIT2 */ /* END */