| /***************************************************************************/ |
| /* */ |
| /* aflatin.c */ |
| /* */ |
| /* Auto-fitter hinting routines for latin script (body). */ |
| /* */ |
| /* Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 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 "aflatin.h" |
| #include "aferrors.h" |
| |
| |
| #ifdef AF_USE_WARPER |
| #include "afwarp.h" |
| #endif |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /***** *****/ |
| /***** L A T I N G L O B A L M E T R I C S *****/ |
| /***** *****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| FT_LOCAL_DEF( void ) |
| af_latin_metrics_init_widths( AF_LatinMetrics metrics, |
| FT_Face face, |
| FT_ULong charcode ) |
| { |
| /* scan the array of segments in each direction */ |
| AF_GlyphHintsRec hints[1]; |
| |
| |
| af_glyph_hints_init( hints, face->memory ); |
| |
| metrics->axis[AF_DIMENSION_HORZ].width_count = 0; |
| metrics->axis[AF_DIMENSION_VERT].width_count = 0; |
| |
| { |
| FT_Error error; |
| FT_UInt glyph_index; |
| int dim; |
| AF_LatinMetricsRec dummy[1]; |
| AF_Scaler scaler = &dummy->root.scaler; |
| |
| |
| glyph_index = FT_Get_Char_Index( face, charcode ); |
| if ( glyph_index == 0 ) |
| goto Exit; |
| |
| error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); |
| if ( error || face->glyph->outline.n_points <= 0 ) |
| goto Exit; |
| |
| FT_ZERO( dummy ); |
| |
| dummy->units_per_em = metrics->units_per_em; |
| scaler->x_scale = 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_ScriptMetrics)dummy ); |
| |
| error = af_glyph_hints_reload( hints, &face->glyph->outline ); |
| if ( error ) |
| goto Exit; |
| |
| for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) |
| { |
| AF_LatinAxis axis = &metrics->axis[dim]; |
| AF_AxisHints axhints = &hints->axis[dim]; |
| AF_Segment seg, limit, link; |
| FT_UInt num_widths = 0; |
| |
| |
| error = af_latin_hints_compute_segments( hints, |
| (AF_Dimension)dim ); |
| if ( error ) |
| goto Exit; |
| |
| af_latin_hints_link_segments( hints, |
| (AF_Dimension)dim ); |
| |
| seg = axhints->segments; |
| limit = seg + axhints->num_segments; |
| |
| for ( ; seg < limit; seg++ ) |
| { |
| link = seg->link; |
| |
| /* we only consider stem segments there! */ |
| if ( link && link->link == seg && link > seg ) |
| { |
| FT_Pos dist; |
| |
| |
| dist = seg->pos - link->pos; |
| if ( dist < 0 ) |
| dist = -dist; |
| |
| if ( num_widths < AF_LATIN_MAX_WIDTHS ) |
| axis->widths[ num_widths++ ].org = dist; |
| } |
| } |
| |
| af_sort_widths( num_widths, axis->widths ); |
| axis->width_count = num_widths; |
| } |
| |
| Exit: |
| for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) |
| { |
| AF_LatinAxis axis = &metrics->axis[dim]; |
| FT_Pos stdw; |
| |
| |
| stdw = ( axis->width_count > 0 ) |
| ? axis->widths[0].org |
| : AF_LATIN_CONSTANT( metrics, 50 ); |
| |
| /* let's try 20% of the smallest width */ |
| axis->edge_distance_threshold = stdw / 5; |
| axis->standard_width = stdw; |
| axis->extra_light = 0; |
| } |
| } |
| |
| af_glyph_hints_done( hints ); |
| } |
| |
| |
| |
| #define AF_LATIN_MAX_TEST_CHARACTERS 12 |
| |
| |
| static const char af_latin_blue_chars[AF_LATIN_MAX_BLUES] |
| [AF_LATIN_MAX_TEST_CHARACTERS + 1] = |
| { |
| "THEZOCQS", |
| "HEZLOCUS", |
| "fijkdbh", |
| "xzroesc", |
| "xzroesc", |
| "pqgjy" |
| }; |
| |
| |
| static void |
| af_latin_metrics_init_blues( AF_LatinMetrics metrics, |
| FT_Face face ) |
| { |
| FT_Pos flats [AF_LATIN_MAX_TEST_CHARACTERS]; |
| FT_Pos rounds[AF_LATIN_MAX_TEST_CHARACTERS]; |
| FT_Int num_flats; |
| FT_Int num_rounds; |
| FT_Int bb; |
| AF_LatinBlue blue; |
| FT_Error error; |
| AF_LatinAxis axis = &metrics->axis[AF_DIMENSION_VERT]; |
| FT_GlyphSlot glyph = face->glyph; |
| |
| |
| /* we compute the blues simply by loading each character from the */ |
| /* 'af_latin_blue_chars[blues]' string, then compute its top-most or */ |
| /* bottom-most points (depending on `AF_IS_TOP_BLUE') */ |
| |
| AF_LOG(( "blue zones computation\n" )); |
| AF_LOG(( "------------------------------------------------\n" )); |
| |
| for ( bb = 0; bb < AF_LATIN_BLUE_MAX; bb++ ) |
| { |
| const char* p = af_latin_blue_chars[bb]; |
| const char* limit = p + AF_LATIN_MAX_TEST_CHARACTERS; |
| FT_Pos* blue_ref; |
| FT_Pos* blue_shoot; |
| |
| |
| AF_LOG(( "blue %3d: ", bb )); |
| |
| num_flats = 0; |
| num_rounds = 0; |
| |
| for ( ; p < limit && *p; p++ ) |
| { |
| FT_UInt glyph_index; |
| FT_Pos best_y; /* same as points.y */ |
| FT_Int best_point, best_first, best_last; |
| FT_Vector* points; |
| FT_Bool round = 0; |
| |
| |
| AF_LOG(( "'%c'", *p )); |
| |
| /* load the character in the face -- skip unknown or empty ones */ |
| glyph_index = FT_Get_Char_Index( face, (FT_UInt)*p ); |
| if ( glyph_index == 0 ) |
| continue; |
| |
| error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); |
| if ( error || glyph->outline.n_points <= 0 ) |
| continue; |
| |
| /* now compute min or max point indices and coordinates */ |
| points = glyph->outline.points; |
| best_point = -1; |
| best_y = 0; /* make compiler happy */ |
| best_first = 0; /* ditto */ |
| best_last = 0; /* ditto */ |
| |
| { |
| FT_Int nn; |
| FT_Int first = 0; |
| FT_Int last = -1; |
| |
| |
| for ( nn = 0; nn < glyph->outline.n_contours; first = last+1, nn++ ) |
| { |
| FT_Int old_best_point = best_point; |
| FT_Int pp; |
| |
| |
| last = glyph->outline.contours[nn]; |
| |
| /* Avoid single-point contours since they are never rasterized. */ |
| /* In some fonts, they correspond to mark attachment points */ |
| /* which are way outside of the glyph's real outline. */ |
| if ( last <= first ) |
| continue; |
| |
| if ( AF_LATIN_IS_TOP_BLUE( bb ) ) |
| { |
| for ( pp = first; pp <= last; pp++ ) |
| if ( best_point < 0 || points[pp].y > best_y ) |
| { |
| best_point = pp; |
| best_y = points[pp].y; |
| } |
| } |
| else |
| { |
| for ( pp = first; pp <= last; pp++ ) |
| if ( best_point < 0 || points[pp].y < best_y ) |
| { |
| best_point = pp; |
| best_y = points[pp].y; |
| } |
| } |
| |
| if ( best_point != old_best_point ) |
| { |
| best_first = first; |
| best_last = last; |
| } |
| } |
| AF_LOG(( "%5d", best_y )); |
| } |
| |
| /* now check whether the point belongs to a straight or round */ |
| /* segment; we first need to find in which contour the extremum */ |
| /* lies, then inspect its previous and next points */ |
| if ( best_point >= 0 ) |
| { |
| FT_Int prev, next; |
| FT_Pos dist; |
| |
| |
| /* now look for the previous and next points that are not on the */ |
| /* same Y coordinate. Threshold the `closeness'... */ |
| prev = best_point; |
| next = prev; |
| |
| do |
| { |
| if ( prev > best_first ) |
| prev--; |
| else |
| prev = best_last; |
| |
| dist = points[prev].y - best_y; |
| if ( dist < -5 || dist > 5 ) |
| break; |
| |
| } while ( prev != best_point ); |
| |
| do |
| { |
| if ( next < best_last ) |
| next++; |
| else |
| next = best_first; |
| |
| dist = points[next].y - best_y; |
| if ( dist < -5 || dist > 5 ) |
| break; |
| |
| } while ( next != best_point ); |
| |
| /* now, set the `round' flag depending on the segment's kind */ |
| round = FT_BOOL( |
| FT_CURVE_TAG( glyph->outline.tags[prev] ) != FT_CURVE_TAG_ON || |
| FT_CURVE_TAG( glyph->outline.tags[next] ) != FT_CURVE_TAG_ON ); |
| |
| AF_LOG(( "%c ", round ? 'r' : 'f' )); |
| } |
| |
| if ( round ) |
| rounds[num_rounds++] = best_y; |
| else |
| flats[num_flats++] = best_y; |
| } |
| |
| AF_LOG(( "\n" )); |
| |
| if ( num_flats == 0 && num_rounds == 0 ) |
| { |
| /* |
| * we couldn't find a single glyph to compute this blue zone, |
| * we will simply ignore it then |
| */ |
| AF_LOG(( "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_shoot = *blue_ref = ( shoot + ref ) / 2; |
| } |
| |
| blue->flags = 0; |
| if ( AF_LATIN_IS_TOP_BLUE( bb ) ) |
| blue->flags |= AF_LATIN_BLUE_TOP; |
| |
| /* |
| * The following flag is used later to adjust the y and x scales |
| * in order to optimize the pixel grid alignment of the top of small |
| * letters. |
| */ |
| if ( bb == AF_LATIN_BLUE_SMALL_TOP ) |
| blue->flags |= AF_LATIN_BLUE_ADJUSTMENT; |
| |
| AF_LOG(( "-- ref = %ld, shoot = %ld\n", *blue_ref, *blue_shoot )); |
| } |
| |
| return; |
| } |
| |
| |
| 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; |
| |
| |
| /* 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_latin_metrics_init( AF_LatinMetrics metrics, |
| FT_Face face ) |
| { |
| FT_Error error = AF_Err_Ok; |
| FT_CharMap oldmap = face->charmap; |
| FT_UInt ee; |
| |
| static const FT_Encoding latin_encodings[] = |
| { |
| FT_ENCODING_UNICODE, |
| FT_ENCODING_APPLE_ROMAN, |
| FT_ENCODING_ADOBE_STANDARD, |
| FT_ENCODING_ADOBE_LATIN_1, |
| FT_ENCODING_NONE /* end of list */ |
| }; |
| |
| |
| metrics->units_per_em = face->units_per_EM; |
| |
| /* do we have a latin charmap in there? */ |
| for ( ee = 0; latin_encodings[ee] != FT_ENCODING_NONE; ee++ ) |
| { |
| error = FT_Select_Charmap( face, latin_encodings[ee] ); |
| if ( !error ) |
| break; |
| } |
| |
| if ( !error ) |
| { |
| /* For now, compute the standard width and height from the `o'. */ |
| af_latin_metrics_init_widths( metrics, face, 'o' ); |
| af_latin_metrics_init_blues( metrics, face ); |
| af_latin_metrics_check_digits( metrics, face ); |
| } |
| |
| FT_Set_Charmap( face, oldmap ); |
| return AF_Err_Ok; |
| } |
| |
| |
| static void |
| af_latin_metrics_scale_dim( AF_LatinMetrics metrics, |
| AF_Scaler scaler, |
| AF_Dimension dim ) |
| { |
| FT_Fixed scale; |
| FT_Pos delta; |
| AF_LatinAxis axis; |
| FT_UInt nn; |
| |
| |
| if ( dim == AF_DIMENSION_HORZ ) |
| { |
| scale = scaler->x_scale; |
| delta = scaler->x_delta; |
| } |
| else |
| { |
| scale = scaler->y_scale; |
| delta = scaler->y_delta; |
| } |
| |
| axis = &metrics->axis[dim]; |
| |
| if ( axis->org_scale == scale && axis->org_delta == delta ) |
| return; |
| |
| axis->org_scale = scale; |
| axis->org_delta = delta; |
| |
| /* |
| * correct X and Y scale to optimize the alignment of the top of small |
| * letters to the pixel grid |
| */ |
| { |
| AF_LatinAxis Axis = &metrics->axis[AF_DIMENSION_VERT]; |
| AF_LatinBlue blue = NULL; |
| |
| |
| for ( nn = 0; nn < Axis->blue_count; nn++ ) |
| { |
| if ( Axis->blues[nn].flags & AF_LATIN_BLUE_ADJUSTMENT ) |
| { |
| blue = &Axis->blues[nn]; |
| break; |
| } |
| } |
| |
| if ( blue ) |
| { |
| FT_Pos scaled = FT_MulFix( blue->shoot.org, scaler->y_scale ); |
| FT_Pos fitted = ( scaled + 40 ) & ~63; |
| |
| |
| if ( scaled != fitted ) |
| { |
| #if 0 |
| if ( dim == AF_DIMENSION_HORZ ) |
| { |
| if ( fitted < scaled ) |
| scale -= scale / 50; /* scale *= 0.98 */ |
| } |
| else |
| #endif |
| if ( dim == AF_DIMENSION_VERT ) |
| { |
| scale = FT_MulDiv( scale, fitted, scaled ); |
| } |
| } |
| } |
| } |
| |
| axis->scale = scale; |
| axis->delta = delta; |
| |
| if ( dim == AF_DIMENSION_HORZ ) |
| { |
| metrics->root.scaler.x_scale = scale; |
| metrics->root.scaler.x_delta = delta; |
| } |
| else |
| { |
| metrics->root.scaler.y_scale = scale; |
| metrics->root.scaler.y_delta = delta; |
| } |
| |
| /* scale the 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 0.75 pixels */ |
| axis->extra_light = |
| (FT_Bool)( FT_MulFix( axis->standard_width, scale ) < 32 + 8 ); |
| |
| if ( dim == AF_DIMENSION_VERT ) |
| { |
| /* scale the blue zones */ |
| for ( nn = 0; nn < axis->blue_count; nn++ ) |
| { |
| AF_LatinBlue blue = &axis->blues[nn]; |
| FT_Pos dist; |
| |
| |
| blue->ref.cur = FT_MulFix( blue->ref.org, scale ) + delta; |
| blue->ref.fit = blue->ref.cur; |
| blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta; |
| blue->shoot.fit = blue->shoot.cur; |
| blue->flags &= ~AF_LATIN_BLUE_ACTIVE; |
| |
| /* a blue zone is only active if it is less than 3/4 pixels tall */ |
| dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale ); |
| if ( dist <= 48 && dist >= -48 ) |
| { |
| FT_Pos delta1, delta2; |
| |
| |
| delta1 = blue->shoot.org - blue->ref.org; |
| delta2 = delta1; |
| if ( delta1 < 0 ) |
| delta2 = -delta2; |
| |
| delta2 = FT_MulFix( delta2, scale ); |
| |
| if ( delta2 < 32 ) |
| delta2 = 0; |
| else if ( delta2 < 64 ) |
| delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 ); |
| else |
| delta2 = FT_PIX_ROUND( delta2 ); |
| |
| if ( delta1 < 0 ) |
| delta2 = -delta2; |
| |
| blue->ref.fit = FT_PIX_ROUND( blue->ref.cur ); |
| blue->shoot.fit = blue->ref.fit + delta2; |
| |
| blue->flags |= AF_LATIN_BLUE_ACTIVE; |
| } |
| } |
| } |
| } |
| |
| |
| FT_LOCAL_DEF( void ) |
| af_latin_metrics_scale( AF_LatinMetrics metrics, |
| AF_Scaler scaler ) |
| { |
| metrics->root.scaler.render_mode = scaler->render_mode; |
| metrics->root.scaler.face = scaler->face; |
| |
| af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ ); |
| af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT ); |
| } |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /***** *****/ |
| /***** L A T I N G L Y P H A N A L Y S I S *****/ |
| /***** *****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| FT_LOCAL_DEF( FT_Error ) |
| af_latin_hints_compute_segments( AF_GlyphHints hints, |
| AF_Dimension dim ) |
| { |
| AF_AxisHints axis = &hints->axis[dim]; |
| FT_Memory memory = hints->memory; |
| FT_Error error = AF_Err_Ok; |
| AF_Segment segment = NULL; |
| AF_SegmentRec seg0; |
| AF_Point* contour = hints->contours; |
| AF_Point* contour_limit = contour + hints->num_contours; |
| AF_Direction major_dir, segment_dir; |
| |
| |
| FT_ZERO( &seg0 ); |
| seg0.score = 32000; |
| seg0.flags = AF_EDGE_NORMAL; |
| |
| major_dir = (AF_Direction)FT_ABS( axis->major_dir ); |
| segment_dir = major_dir; |
| |
| axis->num_segments = 0; |
| |
| /* set up (u,v) in each point */ |
| if ( dim == AF_DIMENSION_HORZ ) |
| { |
| AF_Point point = hints->points; |
| AF_Point limit = point + hints->num_points; |
| |
| |
| for ( ; point < limit; point++ ) |
| { |
| point->u = point->fx; |
| point->v = point->fy; |
| } |
| } |
| else |
| { |
| AF_Point point = hints->points; |
| AF_Point limit = point + hints->num_points; |
| |
| |
| for ( ; point < limit; point++ ) |
| { |
| point->u = point->fy; |
| point->v = point->fx; |
| } |
| } |
| |
| /* do each contour separately */ |
| for ( ; contour < contour_limit; contour++ ) |
| { |
| AF_Point point = contour[0]; |
| AF_Point last = point->prev; |
| int on_edge = 0; |
| FT_Pos min_pos = 32000; /* minimum segment pos != min_coord */ |
| FT_Pos max_pos = -32000; /* maximum segment pos != max_coord */ |
| FT_Bool passed; |
| |
| |
| if ( point == last ) /* skip singletons -- just in case */ |
| continue; |
| |
| if ( FT_ABS( last->out_dir ) == major_dir && |
| FT_ABS( point->out_dir ) == major_dir ) |
| { |
| /* we are already on an edge, try to locate its start */ |
| last = point; |
| |
| for (;;) |
| { |
| point = point->prev; |
| if ( FT_ABS( point->out_dir ) != major_dir ) |
| { |
| point = point->next; |
| break; |
| } |
| if ( point == last ) |
| break; |
| } |
| } |
| |
| last = point; |
| passed = 0; |
| |
| for (;;) |
| { |
| FT_Pos u, v; |
| |
| |
| if ( on_edge ) |
| { |
| u = point->u; |
| if ( u < min_pos ) |
| min_pos = u; |
| if ( u > max_pos ) |
| max_pos = u; |
| |
| if ( point->out_dir != segment_dir || point == last ) |
| { |
| /* we are just leaving an edge; record a new segment! */ |
| segment->last = point; |
| segment->pos = (FT_Short)( ( min_pos + max_pos ) >> 1 ); |
| |
| /* a segment is round if either its first or last point */ |
| /* is a control point */ |
| if ( ( segment->first->flags | point->flags ) & |
| AF_FLAG_CONTROL ) |
| segment->flags |= AF_EDGE_ROUND; |
| |
| /* compute segment size */ |
| min_pos = max_pos = point->v; |
| |
| v = segment->first->v; |
| if ( v < min_pos ) |
| min_pos = v; |
| if ( v > max_pos ) |
| max_pos = v; |
| |
| segment->min_coord = (FT_Short)min_pos; |
| segment->max_coord = (FT_Short)max_pos; |
| segment->height = (FT_Short)( segment->max_coord - |
| segment->min_coord ); |
| |
| on_edge = 0; |
| segment = NULL; |
| /* fallthrough */ |
| } |
| } |
| |
| /* now exit if we are at the start/end point */ |
| if ( point == last ) |
| { |
| if ( passed ) |
| break; |
| passed = 1; |
| } |
| |
| if ( !on_edge && FT_ABS( point->out_dir ) == major_dir ) |
| { |
| /* this is the start of a new segment! */ |
| segment_dir = (AF_Direction)point->out_dir; |
| |
| /* clear all segment fields */ |
| error = af_axis_hints_new_segment( axis, memory, &segment ); |
| if ( error ) |
| goto Exit; |
| |
| segment[0] = seg0; |
| segment->dir = (FT_Char)segment_dir; |
| min_pos = max_pos = point->u; |
| segment->first = point; |
| segment->last = point; |
| segment->contour = contour; |
| on_edge = 1; |
| } |
| |
| point = point->next; |
| } |
| |
| } /* contours */ |
| |
| |
| /* now slightly increase the height of segments when this makes */ |
| /* sense -- this is used to better detect and ignore serifs */ |
| { |
| AF_Segment segments = axis->segments; |
| AF_Segment segments_end = segments + axis->num_segments; |
| |
| |
| for ( segment = segments; segment < segments_end; segment++ ) |
| { |
| AF_Point first = segment->first; |
| AF_Point last = segment->last; |
| FT_Pos first_v = first->v; |
| FT_Pos last_v = last->v; |
| |
| |
| if ( first == last ) |
| continue; |
| |
| if ( first_v < last_v ) |
| { |
| AF_Point p; |
| |
| |
| p = first->prev; |
| if ( p->v < first_v ) |
| segment->height = (FT_Short)( segment->height + |
| ( ( first_v - p->v ) >> 1 ) ); |
| |
| p = last->next; |
| if ( p->v > last_v ) |
| segment->height = (FT_Short)( segment->height + |
| ( ( p->v - last_v ) >> 1 ) ); |
| } |
| else |
| { |
| AF_Point p; |
| |
| |
| p = first->prev; |
| if ( p->v > first_v ) |
| segment->height = (FT_Short)( segment->height + |
| ( ( p->v - first_v ) >> 1 ) ); |
| |
| p = last->next; |
| if ( p->v < last_v ) |
| segment->height = (FT_Short)( segment->height + |
| ( ( last_v - p->v ) >> 1 ) ); |
| } |
| } |
| } |
| |
| Exit: |
| return error; |
| } |
| |
| |
| FT_LOCAL_DEF( void ) |
| af_latin_hints_link_segments( AF_GlyphHints hints, |
| AF_Dimension dim ) |
| { |
| AF_AxisHints axis = &hints->axis[dim]; |
| AF_Segment segments = axis->segments; |
| AF_Segment segment_limit = segments + axis->num_segments; |
| FT_Pos len_threshold, len_score; |
| AF_Segment seg1, seg2; |
| |
| |
| len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 ); |
| if ( len_threshold == 0 ) |
| len_threshold = 1; |
| |
| len_score = AF_LATIN_CONSTANT( hints->metrics, 6000 ); |
| |
| /* now compare each segment to the others */ |
| for ( seg1 = segments; seg1 < segment_limit; seg1++ ) |
| { |
| /* the fake segments are introduced to hint the metrics -- */ |
| /* we must never link them to anything */ |
| if ( seg1->dir != axis->major_dir || seg1->first == seg1->last ) |
| continue; |
| |
| for ( seg2 = segments; seg2 < segment_limit; seg2++ ) |
| if ( seg1->dir + seg2->dir == 0 && seg2->pos > seg1->pos ) |
| { |
| FT_Pos pos1 = seg1->pos; |
| FT_Pos pos2 = seg2->pos; |
| FT_Pos dist = pos2 - pos1; |
| |
| |
| if ( dist < 0 ) |
| dist = -dist; |
| |
| { |
| 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; |
| } |
| } |
| } |
| } |
| } |
| |
| /* now, compute the `serif' segments */ |
| for ( seg1 = segments; seg1 < segment_limit; seg1++ ) |
| { |
| seg2 = seg1->link; |
| |
| if ( seg2 ) |
| { |
| if ( seg2->link != seg1 ) |
| { |
| seg1->link = 0; |
| seg1->serif = seg2->link; |
| } |
| } |
| } |
| } |
| |
| |
| FT_LOCAL_DEF( FT_Error ) |
| af_latin_hints_compute_edges( AF_GlyphHints hints, |
| AF_Dimension dim ) |
| { |
| AF_AxisHints axis = &hints->axis[dim]; |
| FT_Error error = AF_Err_Ok; |
| FT_Memory memory = hints->memory; |
| AF_LatinAxis laxis = &((AF_LatinMetrics)hints->metrics)->axis[dim]; |
| |
| AF_Segment segments = axis->segments; |
| AF_Segment segment_limit = segments + axis->num_segments; |
| AF_Segment seg; |
| |
| AF_Direction up_dir; |
| FT_Fixed scale; |
| FT_Pos edge_distance_threshold; |
| FT_Pos segment_length_threshold; |
| |
| |
| axis->num_edges = 0; |
| |
| scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale |
| : hints->y_scale; |
| |
| up_dir = ( dim == AF_DIMENSION_HORZ ) ? AF_DIR_UP |
| : AF_DIR_RIGHT; |
| |
| /* |
| * We ignore all segments that are less than 1 pixels 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 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 = 0; |
| 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->fpos = seg->pos; |
| edge->dir = seg->dir; |
| edge->opos = edge->pos = FT_MulFix( seg->pos, scale ); |
| 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? */ |
| FT_Pos ups = 0; /* number of upwards segments */ |
| FT_Pos downs = 0; /* number of downwards segments */ |
| |
| |
| seg = edge->first; |
| |
| do |
| { |
| FT_Bool is_serif; |
| |
| |
| /* check for roundness of segment */ |
| if ( seg->flags & AF_EDGE_ROUND ) |
| is_round++; |
| else |
| is_straight++; |
| |
| /* check for segment direction */ |
| if ( seg->dir == up_dir ) |
| ups += seg->max_coord-seg->min_coord; |
| else |
| downs += seg->max_coord-seg->min_coord; |
| |
| /* 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 |
| |
| /* 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 = 0; |
| } |
| } |
| |
| Exit: |
| return error; |
| } |
| |
| |
| FT_LOCAL_DEF( FT_Error ) |
| af_latin_hints_detect_features( AF_GlyphHints hints, |
| AF_Dimension dim ) |
| { |
| FT_Error error; |
| |
| |
| error = af_latin_hints_compute_segments( hints, dim ); |
| if ( !error ) |
| { |
| af_latin_hints_link_segments( hints, dim ); |
| |
| error = af_latin_hints_compute_edges( hints, dim ); |
| } |
| return error; |
| } |
| |
| |
| FT_LOCAL_DEF( void ) |
| af_latin_hints_compute_blue_edges( AF_GlyphHints hints, |
| AF_LatinMetrics metrics ) |
| { |
| AF_AxisHints axis = &hints->axis[ AF_DIMENSION_VERT ]; |
| AF_Edge edge = axis->edges; |
| AF_Edge edge_limit = edge + axis->num_edges; |
| AF_LatinAxis latin = &metrics->axis[ AF_DIMENSION_VERT ]; |
| FT_Fixed scale = latin->scale; |
| |
| |
| /* compute which blue zones are active, i.e. have their scaled */ |
| /* size < 3/4 pixels */ |
| |
| /* for each horizontal edge search the blue zone which is closest */ |
| for ( ; edge < edge_limit; edge++ ) |
| { |
| FT_Int bb; |
| AF_Width best_blue = NULL; |
| FT_Pos best_dist; /* initial threshold */ |
| |
| |
| /* compute the initial threshold as a fraction of the EM size */ |
| best_dist = FT_MulFix( metrics->units_per_em / 40, scale ); |
| |
| if ( best_dist > 64 / 2 ) |
| best_dist = 64 / 2; |
| |
| for ( bb = 0; bb < AF_LATIN_BLUE_MAX; bb++ ) |
| { |
| AF_LatinBlue blue = latin->blues + bb; |
| FT_Bool is_top_blue, is_major_dir; |
| |
| |
| /* skip inactive blue zones (i.e., those that are too 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; |
| |
| |
| /* first of all, compare it to the reference position */ |
| dist = edge->fpos - blue->ref.org; |
| if ( dist < 0 ) |
| dist = -dist; |
| |
| dist = FT_MulFix( dist, scale ); |
| if ( dist < best_dist ) |
| { |
| best_dist = dist; |
| best_blue = & blue->ref; |
| } |
| |
| /* now, compare it to the overshoot position 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; |
| } |
| } |
| } |
| } |
| } |
| |
| if ( best_blue ) |
| edge->blue_edge = best_blue; |
| } |
| } |
| |
| |
| static FT_Error |
| af_latin_hints_init( AF_GlyphHints hints, |
| AF_LatinMetrics metrics ) |
| { |
| FT_Render_Mode mode; |
| FT_UInt32 scaler_flags, other_flags; |
| FT_Face face = metrics->root.scaler.face; |
| |
| |
| af_glyph_hints_rescale( hints, (AF_ScriptMetrics)metrics ); |
| |
| /* |
| * correct x_scale and y_scale if needed, since they may have |
| * been modified `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_USE_WARPER */ |
| if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V ) |
| { |
| metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL; |
| } |
| #endif |
| |
| scaler_flags = hints->scaler_flags; |
| other_flags = 0; |
| |
| /* |
| * We snap the width of vertical stems for the monochrome and |
| * horizontal LCD rendering targets only. |
| */ |
| if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD ) |
| other_flags |= AF_LATIN_HINTS_HORZ_SNAP; |
| |
| /* |
| * We snap the width of horizontal stems for the monochrome and |
| * vertical LCD rendering targets only. |
| */ |
| if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V ) |
| other_flags |= AF_LATIN_HINTS_VERT_SNAP; |
| |
| /* |
| * We adjust stems to full pixels only if we don't use the `light' mode. |
| */ |
| if ( mode != FT_RENDER_MODE_LIGHT ) |
| other_flags |= AF_LATIN_HINTS_STEM_ADJUST; |
| |
| if ( mode == FT_RENDER_MODE_MONO ) |
| other_flags |= AF_LATIN_HINTS_MONO; |
| |
| /* |
| * In `light' hinting mode we disable horizontal hinting completely. |
| * We also do it if the face is italic. |
| */ |
| if ( mode == FT_RENDER_MODE_LIGHT || |
| (face->style_flags & FT_STYLE_FLAG_ITALIC) != 0 ) |
| scaler_flags |= AF_SCALER_FLAG_NO_HORIZONTAL; |
| |
| hints->scaler_flags = scaler_flags; |
| hints->other_flags = other_flags; |
| |
| return 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_latin_snap_width( AF_Width widths, |
| FT_Int count, |
| FT_Pos width ) |
| { |
| int n; |
| FT_Pos best = 64 + 32 + 2; |
| FT_Pos reference = width; |
| FT_Pos scaled; |
| |
| |
| for ( n = 0; n < count; n++ ) |
| { |
| FT_Pos w; |
| FT_Pos dist; |
| |
| |
| w = widths[n].cur; |
| dist = width - w; |
| if ( dist < 0 ) |
| dist = -dist; |
| if ( dist < best ) |
| { |
| best = dist; |
| reference = w; |
| } |
| } |
| |
| scaled = FT_PIX_ROUND( reference ); |
| |
| if ( width >= reference ) |
| { |
| if ( width < scaled + 48 ) |
| width = reference; |
| } |
| else |
| { |
| if ( width > scaled - 48 ) |
| width = reference; |
| } |
| |
| return width; |
| } |
| |
| |
| /* compute the snapped width of a given stem */ |
| |
| static FT_Pos |
| af_latin_compute_stem_width( AF_GlyphHints hints, |
| AF_Dimension dim, |
| FT_Pos width, |
| AF_Edge_Flags base_flags, |
| AF_Edge_Flags stem_flags ) |
| { |
| AF_LatinMetrics metrics = (AF_LatinMetrics) hints->metrics; |
| AF_LatinAxis axis = & metrics->axis[dim]; |
| FT_Pos dist = width; |
| FT_Int sign = 0; |
| FT_Int vertical = ( dim == AF_DIMENSION_VERT ); |
| |
| |
| if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) || |
| axis->extra_light ) |
| return width; |
| |
| if ( dist < 0 ) |
| { |
| dist = -width; |
| sign = 1; |
| } |
| |
| if ( ( vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) || |
| ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) ) |
| { |
| /* smooth hinting process: very lightly quantize the stem width */ |
| |
| /* leave the widths of serifs alone */ |
| |
| if ( ( stem_flags & AF_EDGE_SERIF ) && vertical && ( dist < 3 * 64 ) ) |
| goto Done_Width; |
| |
| else if ( ( base_flags & AF_EDGE_ROUND ) ) |
| { |
| if ( dist < 80 ) |
| dist = 64; |
| } |
| else if ( dist < 56 ) |
| dist = 56; |
| |
| if ( axis->width_count > 0 ) |
| { |
| FT_Pos delta; |
| |
| |
| /* compare to standard width */ |
| 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_latin_snap_width( axis->widths, axis->width_count, dist ); |
| |
| if ( vertical ) |
| { |
| /* in the case of vertical hinting, always round */ |
| /* the stem heights to integer pixels */ |
| |
| if ( dist >= 64 ) |
| dist = ( dist + 16 ) & ~63; |
| else |
| dist = 64; |
| } |
| else |
| { |
| if ( AF_LATIN_HINTS_DO_MONO( hints ) ) |
| { |
| /* monochrome horizontal hinting: snap widths to integer pixels */ |
| /* with a different threshold */ |
| |
| if ( dist < 64 ) |
| dist = 64; |
| else |
| dist = ( dist + 32 ) & ~63; |
| } |
| else |
| { |
| /* for horizontal anti-aliased hinting, we adopt a more subtle */ |
| /* approach: we strengthen small stems, round stems whose size */ |
| /* is between 1 and 2 pixels to an integer, otherwise nothing */ |
| |
| if ( dist < 48 ) |
| dist = ( dist + 64 ) >> 1; |
| |
| else if ( dist < 128 ) |
| { |
| /* We only round to an integer width if the corresponding */ |
| /* distortion is less than 1/4 pixel. Otherwise this */ |
| /* makes everything worse since the diagonals, which are */ |
| /* not hinted, appear a lot bolder or thinner than the */ |
| /* vertical stems. */ |
| |
| FT_Pos delta; |
| |
| |
| dist = ( dist + 22 ) & ~63; |
| delta = dist - org_dist; |
| if ( delta < 0 ) |
| delta = -delta; |
| |
| if (delta >= 16) |
| { |
| dist = org_dist; |
| if ( dist < 48 ) |
| dist = ( dist + 64 ) >> 1; |
| } |
| } |
| else |
| /* round otherwise to prevent color fringes in LCD mode */ |
| dist = ( dist + 32 ) & ~63; |
| } |
| } |
| } |
| |
| Done_Width: |
| if ( sign ) |
| dist = -dist; |
| |
| return dist; |
| } |
| |
| |
| /* align one stem edge relative to the previous stem edge */ |
| |
| static void |
| af_latin_align_linked_edge( AF_GlyphHints hints, |
| AF_Dimension dim, |
| AF_Edge base_edge, |
| AF_Edge stem_edge ) |
| { |
| FT_Pos dist = stem_edge->opos - base_edge->opos; |
| |
| FT_Pos fitted_width = af_latin_compute_stem_width( |
| hints, dim, dist, |
| (AF_Edge_Flags)base_edge->flags, |
| (AF_Edge_Flags)stem_edge->flags ); |
| |
| |
| stem_edge->pos = base_edge->pos + fitted_width; |
| |
| AF_LOG(( "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_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 ****/ |
| /**** ****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| FT_LOCAL_DEF( void ) |
| af_latin_hint_edges( AF_GlyphHints hints, |
| AF_Dimension dim ) |
| { |
| AF_AxisHints axis = &hints->axis[dim]; |
| AF_Edge edges = axis->edges; |
| AF_Edge edge_limit = edges + axis->num_edges; |
| FT_PtrDist n_edges; |
| AF_Edge edge; |
| AF_Edge anchor = 0; |
| FT_Int has_serifs = 0; |
| |
| |
| /* we begin by aligning all stems relative to the blue zone */ |
| /* if needed -- that's only for horizontal edges */ |
| |
| if ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_BLUES( hints ) ) |
| { |
| for ( edge = edges; edge < edge_limit; edge++ ) |
| { |
| AF_Width blue; |
| AF_Edge edge1, edge2; |
| |
| |
| if ( edge->flags & AF_EDGE_DONE ) |
| continue; |
| |
| blue = edge->blue_edge; |
| edge1 = NULL; |
| edge2 = edge->link; |
| |
| if ( blue ) |
| { |
| edge1 = edge; |
| } |
| else if ( edge2 && edge2->blue_edge ) |
| { |
| blue = edge2->blue_edge; |
| edge1 = edge2; |
| edge2 = edge; |
| } |
| |
| if ( !edge1 ) |
| continue; |
| |
| AF_LOG(( "BLUE: edge %d (opos=%.2f) snapped to (%.2f), " |
| "was (%.2f)\n", |
| edge1-edges, edge1->opos / 64.0, blue->fit / 64.0, |
| edge1->pos / 64.0 )); |
| |
| edge1->pos = blue->fit; |
| edge1->flags |= AF_EDGE_DONE; |
| |
| if ( edge2 && !edge2->blue_edge ) |
| { |
| af_latin_align_linked_edge( hints, dim, edge1, edge2 ); |
| edge2->flags |= AF_EDGE_DONE; |
| } |
| |
| if ( !anchor ) |
| anchor = edge; |
| } |
| } |
| |
| /* now we 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 ) |
| { |
| AF_LOG(( "ASSERTION FAILED for edge %d\n", edge2-edges )); |
| |
| af_latin_align_linked_edge( hints, dim, edge2, edge ); |
| edge->flags |= AF_EDGE_DONE; |
| continue; |
| } |
| |
| if ( !anchor ) |
| { |
| FT_Pos org_len, org_center, cur_len; |
| FT_Pos cur_pos1, error1, error2, u_off, d_off; |
| |
| |
| org_len = edge2->opos - edge->opos; |
| cur_len = af_latin_compute_stem_width( |
| hints, dim, org_len, |
| (AF_Edge_Flags)edge->flags, |
| (AF_Edge_Flags)edge2->flags ); |
| 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 ); |
| |
| AF_LOG(( "ANCHOR: edge %d (opos=%.2f) and %d (opos=%.2f) " |
| "snapped to (%.2f) (%.2f)\n", |
| edge-edges, edge->opos / 64.0, |
| edge2-edges, edge2->opos / 64.0, |
| edge->pos / 64.0, edge2->pos / 64.0 )); |
| anchor = edge; |
| |
| edge->flags |= AF_EDGE_DONE; |
| |
| af_latin_align_linked_edge( hints, dim, edge, edge2 ); |
| } |
| else |
| { |
| FT_Pos org_pos, org_len, org_center, cur_len; |
| FT_Pos cur_pos1, cur_pos2, delta1, delta2; |
| |
| |
| org_pos = anchor->pos + ( edge->opos - anchor->opos ); |
| org_len = edge2->opos - edge->opos; |
| org_center = org_pos + ( org_len >> 1 ); |
| |
| cur_len = af_latin_compute_stem_width( |
| hints, dim, org_len, |
| (AF_Edge_Flags)edge->flags, |
| (AF_Edge_Flags)edge2->flags ); |
| |
| if ( edge2->flags & AF_EDGE_DONE ) |
| edge->pos = edge2->pos - cur_len; |
| |
| else if ( cur_len < 96 ) |
| { |
| FT_Pos u_off, d_off; |
| |
| |
| cur_pos1 = FT_PIX_ROUND( org_center ); |
| |
| if (cur_len <= 64 ) |
| u_off = 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; |
| |
| AF_LOG(( "STEM: %d (opos=%.2f) to %d (opos=%.2f) " |
| "snapped to (%.2f) and (%.2f)\n", |
| edge-edges, edge->opos / 64.0, |
| edge2-edges, edge2->opos / 64.0, |
| edge->pos / 64.0, edge2->pos / 64.0 )); |
| } |
| else |
| { |
| org_pos = anchor->pos + ( edge->opos - anchor->opos ); |
| org_len = edge2->opos - edge->opos; |
| org_center = org_pos + ( org_len >> 1 ); |
| |
| cur_len = af_latin_compute_stem_width( |
| hints, dim, org_len, |
| (AF_Edge_Flags)edge->flags, |
| (AF_Edge_Flags)edge2->flags ); |
| |
| cur_pos1 = FT_PIX_ROUND( org_pos ); |
| delta1 = cur_pos1 + ( cur_len >> 1 ) - org_center; |
| if ( delta1 < 0 ) |
| delta1 = -delta1; |
| |
| cur_pos2 = FT_PIX_ROUND( org_pos + org_len ) - cur_len; |
| delta2 = cur_pos2 + ( cur_len >> 1 ) - org_center; |
| if ( delta2 < 0 ) |
| delta2 = -delta2; |
| |
| edge->pos = ( delta1 < delta2 ) ? cur_pos1 : cur_pos2; |
| edge2->pos = edge->pos + cur_len; |
| |
| AF_LOG(( "STEM: %d (opos=%.2f) to %d (opos=%.2f) " |
| "snapped to (%.2f) and (%.2f)\n", |
| edge-edges, edge->opos / 64.0, |
| edge2-edges, edge2->opos / 64.0, |
| edge->pos / 64.0, edge2->pos / 64.0 )); |
| } |
| |
| edge->flags |= AF_EDGE_DONE; |
| edge2->flags |= AF_EDGE_DONE; |
| |
| if ( edge > edges && edge->pos < edge[-1].pos ) |
| { |
| AF_LOG(( "BOUND: %d (pos=%.2f) to (%.2f)\n", |
| edge-edges, edge->pos / 64.0, edge[-1].pos / 64.0 )); |
| edge->pos = edge[-1].pos; |
| } |
| } |
| } |
| |
| /* make sure that lowercase m's maintain their symmetry */ |
| |
| /* In general, lowercase m's have six vertical edges if they are sans */ |
| /* serif, or twelve if they are with serifs. This implementation is */ |
| /* based on that assumption, and seems to work very well with most */ |
| /* faces. However, if for a certain face this assumption is not */ |
| /* true, the m is just rendered like before. In addition, any stem */ |
| /* correction will only be applied to symmetrical glyphs (even if the */ |
| /* glyph is not an m), so the potential for unwanted distortion is */ |
| /* relatively low. */ |
| |
| /* We don't handle horizontal edges since we can't easily assure that */ |
| /* the third (lowest) stem aligns with the base line; it might end up */ |
| /* one pixel higher or lower. */ |
| |
| n_edges = edge_limit - edges; |
| if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) ) |
| { |
| AF_Edge edge1, edge2, edge3; |
| FT_Pos dist1, dist2, span, delta; |
| |
| |
| if ( n_edges == 6 ) |
| { |
| edge1 = edges; |
| edge2 = edges + 2; |
| edge3 = edges + 4; |
| } |
| else |
| { |
| edge1 = edges + 1; |
| edge2 = edges + 5; |
| edge3 = edges + 9; |
| } |
| |
| dist1 = edge2->opos - edge1->opos; |
| dist2 = edge3->opos - edge2->opos; |
| |
| span = dist1 - dist2; |
| if ( span < 0 ) |
| span = -span; |
| |
| if ( span < 8 ) |
| { |
| delta = edge3->pos - ( 2 * edge2->pos - edge1->pos ); |
| edge3->pos -= delta; |
| if ( edge3->link ) |
| edge3->link->pos -= delta; |
| |
| /* move the serifs along with the stem */ |
| if ( n_edges == 12 ) |
| { |
| ( edges + 8 )->pos -= delta; |
| ( edges + 11 )->pos -= delta; |
| } |
| |
| edge3->flags |= AF_EDGE_DONE; |
| if ( edge3->link ) |
| edge3->link->flags |= AF_EDGE_DONE; |
| } |
| } |
| |
| if ( has_serifs || !anchor ) |
| { |
| /* |
| * now hint the remaining edges (serifs and single) in order |
| * to complete our processing |
| */ |
| for ( edge = edges; edge < edge_limit; edge++ ) |
| { |
| FT_Pos delta; |
| |
| |
| if ( edge->flags & AF_EDGE_DONE ) |
| continue; |
| |
| delta = 1000; |
| |
| if ( edge->serif ) |
| { |
| delta = edge->serif->opos - edge->opos; |
| if ( delta < 0 ) |
| delta = -delta; |
| } |
| |
| if ( delta < 64 + 16 ) |
| { |
| af_latin_align_serif_edge( hints, edge->serif, edge ); |
| AF_LOG(( "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 ) |
| { |
| AF_LOG(( "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 ); |
| AF_LOG(( "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 ); |
| AF_LOG(( "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_latin_hints_apply( AF_GlyphHints hints, |
| FT_Outline* outline, |
| AF_LatinMetrics metrics ) |
| { |
| FT_Error error; |
| int dim; |
| |
| |
| error = af_glyph_hints_reload( hints, outline ); |
| if ( error ) |
| goto Exit; |
| |
| /* analyze glyph outline */ |
| #ifdef AF_USE_WARPER |
| if ( metrics->root.scaler.render_mode == FT_RENDER_MODE_LIGHT || |
| AF_HINTS_DO_HORIZONTAL( hints ) ) |
| #else |
| if ( AF_HINTS_DO_HORIZONTAL( hints ) ) |
| #endif |
| { |
| error = af_latin_hints_detect_features( hints, AF_DIMENSION_HORZ ); |
| if ( error ) |
| goto Exit; |
| } |
| |
| if ( AF_HINTS_DO_VERTICAL( hints ) ) |
| { |
| error = af_latin_hints_detect_features( hints, AF_DIMENSION_VERT ); |
| if ( error ) |
| goto Exit; |
| |
| af_latin_hints_compute_blue_edges( hints, metrics ); |
| } |
| |
| /* grid-fit the outline */ |
| for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) |
| { |
| #ifdef AF_USE_WARPER |
| if ( ( dim == AF_DIMENSION_HORZ && |
| metrics->root.scaler.render_mode == FT_RENDER_MODE_LIGHT ) ) |
| { |
| AF_WarperRec warper; |
| FT_Fixed scale; |
| FT_Pos delta; |
| |
| |
| af_warper_compute( &warper, hints, dim, &scale, &delta ); |
| af_glyph_hints_scale_dim( hints, dim, scale, delta ); |
| continue; |
| } |
| #endif |
| |
| if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) || |
| ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) ) ) |
| { |
| af_latin_hint_edges( hints, (AF_Dimension)dim ); |
| af_glyph_hints_align_edge_points( hints, (AF_Dimension)dim ); |
| af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim ); |
| af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim ); |
| } |
| } |
| af_glyph_hints_save( hints, outline ); |
| |
| Exit: |
| return error; |
| } |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /***** *****/ |
| /***** L A T I N S C R I P T C L A S S *****/ |
| /***** *****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| /* XXX: this should probably fine tuned to differentiate better between */ |
| /* scripts... */ |
| |
| static const AF_Script_UniRangeRec af_latin_uniranges[] = |
| { |
| AF_UNIRANGE_REC( 0x0020UL, 0x007FUL ), /* Basic Latin (no control chars) */ |
| AF_UNIRANGE_REC( 0x00A0UL, 0x00FFUL ), /* Latin-1 Supplement (no control chars) */ |
| AF_UNIRANGE_REC( 0x0100UL, 0x017FUL ), /* Latin Extended-A */ |
| AF_UNIRANGE_REC( 0x0180UL, 0x024FUL ), /* Latin Extended-B */ |
| AF_UNIRANGE_REC( 0x0250UL, 0x02AFUL ), /* IPA Extensions */ |
| AF_UNIRANGE_REC( 0x02B0UL, 0x02FFUL ), /* Spacing Modifier Letters */ |
| AF_UNIRANGE_REC( 0x0300UL, 0x036FUL ), /* Combining Diacritical Marks */ |
| AF_UNIRANGE_REC( 0x0370UL, 0x03FFUL ), /* Greek and Coptic */ |
| AF_UNIRANGE_REC( 0x0400UL, 0x04FFUL ), /* Cyrillic */ |
| AF_UNIRANGE_REC( 0x0500UL, 0x052FUL ), /* Cyrillic Supplement */ |
| AF_UNIRANGE_REC( 0x1D00UL, 0x1D7FUL ), /* Phonetic Extensions */ |
| AF_UNIRANGE_REC( 0x1D80UL, 0x1DBFUL ), /* Phonetic Extensions Supplement */ |
| AF_UNIRANGE_REC( 0x1DC0UL, 0x1DFFUL ), /* Combining Diacritical Marks Supplement */ |
| AF_UNIRANGE_REC( 0x1E00UL, 0x1EFFUL ), /* Latin Extended Additional */ |
| AF_UNIRANGE_REC( 0x1F00UL, 0x1FFFUL ), /* Greek Extended */ |
| AF_UNIRANGE_REC( 0x2000UL, 0x206FUL ), /* General Punctuation */ |
| AF_UNIRANGE_REC( 0x2070UL, 0x209FUL ), /* Superscripts and Subscripts */ |
| AF_UNIRANGE_REC( 0x20A0UL, 0x20CFUL ), /* Currency Symbols */ |
| AF_UNIRANGE_REC( 0x2150UL, 0x218FUL ), /* Number Forms */ |
| AF_UNIRANGE_REC( 0x2460UL, 0x24FFUL ), /* Enclosed Alphanumerics */ |
| AF_UNIRANGE_REC( 0x2C60UL, 0x2C7FUL ), /* Latin Extended-C */ |
| AF_UNIRANGE_REC( 0x2DE0UL, 0x2DFFUL ), /* Cyrillic Extended-A */ |
| AF_UNIRANGE_REC( 0xA640UL, 0xA69FUL ), /* Cyrillic Extended-B */ |
| AF_UNIRANGE_REC( 0xA720UL, 0xA7FFUL ), /* Latin Extended-D */ |
| AF_UNIRANGE_REC( 0xFB00UL, 0xFB06UL ), /* Alphab. Present. Forms (Latin Ligs) */ |
| AF_UNIRANGE_REC( 0x1D400UL, 0x1D7FFUL ), /* Mathematical Alphanumeric Symbols */ |
| AF_UNIRANGE_REC( 0UL, 0UL ) |
| }; |
| |
| |
| AF_DEFINE_SCRIPT_CLASS(af_latin_script_class, |
| AF_SCRIPT_LATIN, |
| af_latin_uniranges, |
| |
| sizeof( AF_LatinMetricsRec ), |
| |
| (AF_Script_InitMetricsFunc) af_latin_metrics_init, |
| (AF_Script_ScaleMetricsFunc)af_latin_metrics_scale, |
| (AF_Script_DoneMetricsFunc) NULL, |
| |
| (AF_Script_InitHintsFunc) af_latin_hints_init, |
| (AF_Script_ApplyHintsFunc) af_latin_hints_apply |
| ) |
| |
| |
| /* END */ |