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Diffstat (limited to 'modules/freetype2/src/autofit/afcjk.c')
| -rw-r--r-- | modules/freetype2/src/autofit/afcjk.c | 2375 |
1 files changed, 2375 insertions, 0 deletions
diff --git a/modules/freetype2/src/autofit/afcjk.c b/modules/freetype2/src/autofit/afcjk.c new file mode 100644 index 0000000000..5daefff359 --- /dev/null +++ b/modules/freetype2/src/autofit/afcjk.c @@ -0,0 +1,2375 @@ +/**************************************************************************** + * + * afcjk.c + * + * Auto-fitter hinting routines for CJK writing system (body). + * + * Copyright (C) 2006-2023 by + * David Turner, Robert Wilhelm, and Werner Lemberg. + * + * This file is part of the FreeType project, and may only be used, + * modified, and distributed under the terms of the FreeType project + * license, LICENSE.TXT. By continuing to use, modify, or distribute + * this file you indicate that you have read the license and + * understand and accept it fully. + * + */ + + /* + * The algorithm is based on akito's autohint patch, archived at + * + * https://web.archive.org/web/20051219160454/http://www.kde.gr.jp:80/~akito/patch/freetype2/2.1.7/ + * + */ + +#include <freetype/ftadvanc.h> +#include <freetype/internal/ftdebug.h> + +#include "afglobal.h" +#include "aflatin.h" +#include "afcjk.h" + + +#ifdef AF_CONFIG_OPTION_CJK + +#undef AF_CONFIG_OPTION_CJK_BLUE_HANI_VERT + +#include "aferrors.h" + + + /************************************************************************** + * + * The macro FT_COMPONENT is used in trace mode. It is an implicit + * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log + * messages during execution. + */ +#undef FT_COMPONENT +#define FT_COMPONENT afcjk + + + /*************************************************************************/ + /*************************************************************************/ + /***** *****/ + /***** C J K G L O B A L M E T R I C S *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + + + /* Basically the Latin version with AF_CJKMetrics */ + /* to replace AF_LatinMetrics. */ + + FT_LOCAL_DEF( void ) + af_cjk_metrics_init_widths( AF_CJKMetrics metrics, + FT_Face face ) + { + /* scan the array of segments in each direction */ + AF_GlyphHintsRec hints[1]; + + + FT_TRACE5(( "\n" )); + FT_TRACE5(( "cjk standard widths computation (style `%s')\n", + af_style_names[metrics->root.style_class->style] )); + FT_TRACE5(( "===================================================\n" )); + FT_TRACE5(( "\n" )); + + af_glyph_hints_init( hints, face->memory ); + + metrics->axis[AF_DIMENSION_HORZ].width_count = 0; + metrics->axis[AF_DIMENSION_VERT].width_count = 0; + + { + FT_Error error; + FT_ULong glyph_index; + int dim; + AF_CJKMetricsRec dummy[1]; + AF_Scaler scaler = &dummy->root.scaler; + + AF_StyleClass style_class = metrics->root.style_class; + AF_ScriptClass script_class = af_script_classes[style_class->script]; + + /* If HarfBuzz is not available, we need a pointer to a single */ + /* unsigned long value. */ +#ifdef FT_CONFIG_OPTION_USE_HARFBUZZ + void* shaper_buf; +#else + FT_ULong shaper_buf_; + void* shaper_buf = &shaper_buf_; +#endif + + const char* p; + +#ifdef FT_DEBUG_LEVEL_TRACE + FT_ULong ch = 0; +#endif + + p = script_class->standard_charstring; + +#ifdef FT_CONFIG_OPTION_USE_HARFBUZZ + shaper_buf = af_shaper_buf_create( face ); +#endif + + /* We check a list of standard characters. The first match wins. */ + + glyph_index = 0; + while ( *p ) + { + unsigned int num_idx; + +#ifdef FT_DEBUG_LEVEL_TRACE + const char* p_old; +#endif + + + while ( *p == ' ' ) + p++; + +#ifdef FT_DEBUG_LEVEL_TRACE + p_old = p; + GET_UTF8_CHAR( ch, p_old ); +#endif + + /* reject input that maps to more than a single glyph */ + p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx ); + if ( num_idx > 1 ) + continue; + + /* otherwise exit loop if we have a result */ + glyph_index = af_shaper_get_elem( &metrics->root, + shaper_buf, + 0, + NULL, + NULL ); + if ( glyph_index ) + break; + } + + af_shaper_buf_destroy( face, shaper_buf ); + + if ( !glyph_index ) + goto Exit; + + if ( !glyph_index ) + goto Exit; + + FT_TRACE5(( "standard character: U+%04lX (glyph index %ld)\n", + ch, glyph_index )); + + error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); + if ( error || face->glyph->outline.n_points <= 0 ) + goto Exit; + + FT_ZERO( dummy ); + + dummy->units_per_em = metrics->units_per_em; + + scaler->x_scale = 0x10000L; + scaler->y_scale = 0x10000L; + scaler->x_delta = 0; + scaler->y_delta = 0; + + scaler->face = face; + scaler->render_mode = FT_RENDER_MODE_NORMAL; + scaler->flags = 0; + + af_glyph_hints_rescale( hints, (AF_StyleMetrics)dummy ); + + error = af_glyph_hints_reload( hints, &face->glyph->outline ); + if ( error ) + goto Exit; + + for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) + { + AF_CJKAxis axis = &metrics->axis[dim]; + AF_AxisHints axhints = &hints->axis[dim]; + AF_Segment seg, limit, link; + FT_UInt num_widths = 0; + + + error = af_latin_hints_compute_segments( hints, + (AF_Dimension)dim ); + if ( error ) + goto Exit; + + /* + * We assume that the glyphs selected for the stem width + * computation are `featureless' enough so that the linking + * algorithm works fine without adjustments of its scoring + * function. + */ + af_latin_hints_link_segments( hints, + 0, + NULL, + (AF_Dimension)dim ); + + seg = axhints->segments; + limit = seg + axhints->num_segments; + + for ( ; seg < limit; seg++ ) + { + link = seg->link; + + /* we only consider stem segments there! */ + if ( link && link->link == seg && link > seg ) + { + FT_Pos dist; + + + dist = seg->pos - link->pos; + if ( dist < 0 ) + dist = -dist; + + if ( num_widths < AF_CJK_MAX_WIDTHS ) + axis->widths[num_widths++].org = dist; + } + } + + /* this also replaces multiple almost identical stem widths */ + /* with a single one (the value 100 is heuristic) */ + af_sort_and_quantize_widths( &num_widths, axis->widths, + dummy->units_per_em / 100 ); + axis->width_count = num_widths; + } + + Exit: + for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) + { + AF_CJKAxis axis = &metrics->axis[dim]; + FT_Pos stdw; + + + stdw = ( axis->width_count > 0 ) ? axis->widths[0].org + : AF_LATIN_CONSTANT( metrics, 50 ); + + /* let's try 20% of the smallest width */ + axis->edge_distance_threshold = stdw / 5; + axis->standard_width = stdw; + axis->extra_light = 0; + +#ifdef FT_DEBUG_LEVEL_TRACE + { + FT_UInt i; + + + FT_TRACE5(( "%s widths:\n", + dim == AF_DIMENSION_VERT ? "horizontal" + : "vertical" )); + + FT_TRACE5(( " %ld (standard)", axis->standard_width )); + for ( i = 1; i < axis->width_count; i++ ) + FT_TRACE5(( " %ld", axis->widths[i].org )); + + FT_TRACE5(( "\n" )); + } +#endif + } + } + + FT_TRACE5(( "\n" )); + + af_glyph_hints_done( hints ); + } + + + /* Find all blue zones. */ + + static void + af_cjk_metrics_init_blues( AF_CJKMetrics metrics, + FT_Face face ) + { + FT_Pos fills[AF_BLUE_STRING_MAX_LEN]; + FT_Pos flats[AF_BLUE_STRING_MAX_LEN]; + + FT_UInt num_fills; + FT_UInt num_flats; + + FT_Bool fill; + + AF_CJKBlue blue; + FT_Error error; + AF_CJKAxis axis; + FT_Outline outline; + + AF_StyleClass sc = metrics->root.style_class; + + AF_Blue_Stringset bss = sc->blue_stringset; + const AF_Blue_StringRec* bs = &af_blue_stringsets[bss]; + + /* If HarfBuzz is not available, we need a pointer to a single */ + /* unsigned long value. */ +#ifdef FT_CONFIG_OPTION_USE_HARFBUZZ + void* shaper_buf; +#else + FT_ULong shaper_buf_; + void* shaper_buf = &shaper_buf_; +#endif + + + /* we walk over the blue character strings as specified in the */ + /* style's entry in the `af_blue_stringset' array, computing its */ + /* extremum points (depending on the string properties) */ + + FT_TRACE5(( "cjk blue zones computation\n" )); + FT_TRACE5(( "==========================\n" )); + FT_TRACE5(( "\n" )); + +#ifdef FT_CONFIG_OPTION_USE_HARFBUZZ + shaper_buf = af_shaper_buf_create( face ); +#endif + + for ( ; bs->string != AF_BLUE_STRING_MAX; bs++ ) + { + const char* p = &af_blue_strings[bs->string]; + FT_Pos* blue_ref; + FT_Pos* blue_shoot; + + + if ( AF_CJK_IS_HORIZ_BLUE( bs ) ) + axis = &metrics->axis[AF_DIMENSION_HORZ]; + else + axis = &metrics->axis[AF_DIMENSION_VERT]; + +#ifdef FT_DEBUG_LEVEL_TRACE + { + FT_String* cjk_blue_name[4] = + { + (FT_String*)"bottom", /* -- , -- */ + (FT_String*)"top", /* -- , TOP */ + (FT_String*)"left", /* HORIZ, -- */ + (FT_String*)"right" /* HORIZ, TOP */ + }; + + + FT_TRACE5(( "blue zone %d (%s):\n", + axis->blue_count, + cjk_blue_name[AF_CJK_IS_HORIZ_BLUE( bs ) | + AF_CJK_IS_TOP_BLUE( bs ) ] )); + } +#endif /* FT_DEBUG_LEVEL_TRACE */ + + num_fills = 0; + num_flats = 0; + + fill = 1; /* start with characters that define fill values */ + FT_TRACE5(( " [overshoot values]\n" )); + + while ( *p ) + { + FT_ULong glyph_index; + FT_Pos best_pos; /* same as points.y or points.x, resp. */ + FT_Int best_point; + FT_Vector* points; + + unsigned int num_idx; + +#ifdef FT_DEBUG_LEVEL_TRACE + const char* p_old; + FT_ULong ch; +#endif + + + while ( *p == ' ' ) + p++; + +#ifdef FT_DEBUG_LEVEL_TRACE + p_old = p; + GET_UTF8_CHAR( ch, p_old ); +#endif + + /* switch to characters that define flat values */ + if ( *p == '|' ) + { + fill = 0; + FT_TRACE5(( " [reference values]\n" )); + p++; + continue; + } + + /* reject input that maps to more than a single glyph */ + p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx ); + if ( num_idx > 1 ) + continue; + + /* load the character in the face -- skip unknown or empty ones */ + glyph_index = af_shaper_get_elem( &metrics->root, + shaper_buf, + 0, + NULL, + NULL ); + if ( glyph_index == 0 ) + { + FT_TRACE5(( " U+%04lX unavailable\n", ch )); + continue; + } + + error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); + outline = face->glyph->outline; + if ( error || outline.n_points <= 2 ) + { + FT_TRACE5(( " U+%04lX contains no (usable) outlines\n", ch )); + continue; + } + + /* now compute min or max point indices and coordinates */ + points = outline.points; + best_point = -1; + best_pos = 0; /* make compiler happy */ + + { + FT_Int nn; + FT_Int first = 0; + FT_Int last = -1; + + + for ( nn = 0; nn < outline.n_contours; first = last + 1, nn++ ) + { + FT_Int pp; + + + last = outline.contours[nn]; + + /* Avoid single-point contours since they are never rasterized. */ + /* In some fonts, they correspond to mark attachment points */ + /* which are way outside of the glyph's real outline. */ + if ( last <= first ) + continue; + + if ( AF_CJK_IS_HORIZ_BLUE( bs ) ) + { + if ( AF_CJK_IS_RIGHT_BLUE( bs ) ) + { + for ( pp = first; pp <= last; pp++ ) + if ( best_point < 0 || points[pp].x > best_pos ) + { + best_point = pp; + best_pos = points[pp].x; + } + } + else + { + for ( pp = first; pp <= last; pp++ ) + if ( best_point < 0 || points[pp].x < best_pos ) + { + best_point = pp; + best_pos = points[pp].x; + } + } + } + else + { + if ( AF_CJK_IS_TOP_BLUE( bs ) ) + { + for ( pp = first; pp <= last; pp++ ) + if ( best_point < 0 || points[pp].y > best_pos ) + { + best_point = pp; + best_pos = points[pp].y; + } + } + else + { + for ( pp = first; pp <= last; pp++ ) + if ( best_point < 0 || points[pp].y < best_pos ) + { + best_point = pp; + best_pos = points[pp].y; + } + } + } + } + + FT_TRACE5(( " U+%04lX: best_pos = %5ld\n", ch, best_pos )); + } + + if ( fill ) + fills[num_fills++] = best_pos; + else + flats[num_flats++] = best_pos; + + } /* end while loop */ + + if ( num_flats == 0 && num_fills == 0 ) + { + /* + * we couldn't find a single glyph to compute this blue zone, + * we will simply ignore it then + */ + FT_TRACE5(( " empty\n" )); + continue; + } + + /* we have computed the contents of the `fill' and `flats' tables, */ + /* now determine the reference and overshoot position of the blue -- */ + /* we simply take the median value after a simple sort */ + af_sort_pos( num_fills, fills ); + af_sort_pos( num_flats, flats ); + + blue = &axis->blues[axis->blue_count]; + blue_ref = &blue->ref.org; + blue_shoot = &blue->shoot.org; + + axis->blue_count++; + + if ( num_flats == 0 ) + { + *blue_ref = + *blue_shoot = fills[num_fills / 2]; + } + else if ( num_fills == 0 ) + { + *blue_ref = + *blue_shoot = flats[num_flats / 2]; + } + else + { + *blue_ref = fills[num_fills / 2]; + *blue_shoot = flats[num_flats / 2]; + } + + /* make sure blue_ref >= blue_shoot for top/right or */ + /* vice versa for bottom/left */ + if ( *blue_shoot != *blue_ref ) + { + FT_Pos ref = *blue_ref; + FT_Pos shoot = *blue_shoot; + FT_Bool under_ref = FT_BOOL( shoot < ref ); + + + /* AF_CJK_IS_TOP_BLUE covers `right' and `top' */ + if ( AF_CJK_IS_TOP_BLUE( bs ) ^ under_ref ) + { + *blue_ref = + *blue_shoot = ( shoot + ref ) / 2; + + FT_TRACE5(( " [reference smaller than overshoot," + " taking mean value]\n" )); + } + } + + blue->flags = 0; + if ( AF_CJK_IS_TOP_BLUE( bs ) ) + blue->flags |= AF_CJK_BLUE_TOP; + + FT_TRACE5(( " -> reference = %ld\n", *blue_ref )); + FT_TRACE5(( " overshoot = %ld\n", *blue_shoot )); + + } /* end for loop */ + + af_shaper_buf_destroy( face, shaper_buf ); + + FT_TRACE5(( "\n" )); + + return; + } + + + /* Basically the Latin version with type AF_CJKMetrics for metrics. */ + + FT_LOCAL_DEF( void ) + af_cjk_metrics_check_digits( AF_CJKMetrics metrics, + FT_Face face ) + { + FT_Bool started = 0, same_width = 1; + FT_Fixed advance = 0, old_advance = 0; + + /* If HarfBuzz is not available, we need a pointer to a single */ + /* unsigned long value. */ +#ifdef FT_CONFIG_OPTION_USE_HARFBUZZ + void* shaper_buf; +#else + FT_ULong shaper_buf_; + void* shaper_buf = &shaper_buf_; +#endif + + /* in all supported charmaps, digits have character codes 0x30-0x39 */ + const char digits[] = "0 1 2 3 4 5 6 7 8 9"; + const char* p; + + + p = digits; + +#ifdef FT_CONFIG_OPTION_USE_HARFBUZZ + shaper_buf = af_shaper_buf_create( face ); +#endif + + while ( *p ) + { + FT_ULong glyph_index; + unsigned int num_idx; + + + /* reject input that maps to more than a single glyph */ + p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx ); + if ( num_idx > 1 ) + continue; + + glyph_index = af_shaper_get_elem( &metrics->root, + shaper_buf, + 0, + &advance, + NULL ); + if ( !glyph_index ) + continue; + + if ( started ) + { + if ( advance != old_advance ) + { + same_width = 0; + break; + } + } + else + { + old_advance = advance; + started = 1; + } + } + + af_shaper_buf_destroy( face, shaper_buf ); + + metrics->root.digits_have_same_width = same_width; + } + + + /* Initialize global metrics. */ + + FT_LOCAL_DEF( FT_Error ) + af_cjk_metrics_init( AF_CJKMetrics metrics, + FT_Face face ) + { + FT_CharMap oldmap = face->charmap; + + + metrics->units_per_em = face->units_per_EM; + + if ( !FT_Select_Charmap( face, FT_ENCODING_UNICODE ) ) + { + af_cjk_metrics_init_widths( metrics, face ); + af_cjk_metrics_init_blues( metrics, face ); + af_cjk_metrics_check_digits( metrics, face ); + } + + face->charmap = oldmap; + return FT_Err_Ok; + } + + + /* Adjust scaling value, then scale and shift widths */ + /* and blue zones (if applicable) for given dimension. */ + + static void + af_cjk_metrics_scale_dim( AF_CJKMetrics metrics, + AF_Scaler scaler, + AF_Dimension dim ) + { + FT_Fixed scale; + FT_Pos delta; + AF_CJKAxis axis; + FT_UInt nn; + + + if ( dim == AF_DIMENSION_HORZ ) + { + scale = scaler->x_scale; + delta = scaler->x_delta; + } + else + { + scale = scaler->y_scale; + delta = scaler->y_delta; + } + + axis = &metrics->axis[dim]; + + if ( axis->org_scale == scale && axis->org_delta == delta ) + return; + + axis->org_scale = scale; + axis->org_delta = delta; + + axis->scale = scale; + axis->delta = delta; + + /* scale the blue zones */ + for ( nn = 0; nn < axis->blue_count; nn++ ) + { + AF_CJKBlue blue = &axis->blues[nn]; + FT_Pos dist; + + + blue->ref.cur = FT_MulFix( blue->ref.org, scale ) + delta; + blue->ref.fit = blue->ref.cur; + blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta; + blue->shoot.fit = blue->shoot.cur; + blue->flags &= ~AF_CJK_BLUE_ACTIVE; + + /* a blue zone is only active if it is less than 3/4 pixels tall */ + dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale ); + if ( dist <= 48 && dist >= -48 ) + { + FT_Pos delta1, delta2; + + + blue->ref.fit = FT_PIX_ROUND( blue->ref.cur ); + + /* shoot is under shoot for cjk */ + delta1 = FT_DivFix( blue->ref.fit, scale ) - blue->shoot.org; + delta2 = delta1; + if ( delta1 < 0 ) + delta2 = -delta2; + + delta2 = FT_MulFix( delta2, scale ); + + FT_TRACE5(( "delta: %ld", delta1 )); + if ( delta2 < 32 ) + delta2 = 0; +#if 0 + else if ( delta2 < 64 ) + delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 ); +#endif + else + delta2 = FT_PIX_ROUND( delta2 ); + FT_TRACE5(( "/%ld\n", delta2 )); + + if ( delta1 < 0 ) + delta2 = -delta2; + + blue->shoot.fit = blue->ref.fit - delta2; + + FT_TRACE5(( ">> active cjk blue zone %c%d[%ld/%ld]:\n", + ( dim == AF_DIMENSION_HORZ ) ? 'H' : 'V', + nn, blue->ref.org, blue->shoot.org )); + FT_TRACE5(( " ref: cur=%.2f fit=%.2f\n", + (double)blue->ref.cur / 64, + (double)blue->ref.fit / 64 )); + FT_TRACE5(( " shoot: cur=%.2f fit=%.2f\n", + (double)blue->shoot.cur / 64, + (double)blue->shoot.fit / 64 )); + + blue->flags |= AF_CJK_BLUE_ACTIVE; + } + } + } + + + /* Scale global values in both directions. */ + + FT_LOCAL_DEF( void ) + af_cjk_metrics_scale( AF_CJKMetrics metrics, + AF_Scaler scaler ) + { + /* we copy the whole structure since the x and y scaling values */ + /* are not modified, contrary to e.g. the `latin' auto-hinter */ + metrics->root.scaler = *scaler; + + af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ ); + af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT ); + } + + + /* Extract standard_width from writing system/script specific */ + /* metrics class. */ + + FT_LOCAL_DEF( void ) + af_cjk_get_standard_widths( AF_CJKMetrics 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; + } + + + /*************************************************************************/ + /*************************************************************************/ + /***** *****/ + /***** C J K G L Y P H A N A L Y S I S *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + + + /* Walk over all contours and compute its segments. */ + + static FT_Error + af_cjk_hints_compute_segments( AF_GlyphHints hints, + AF_Dimension dim ) + { + AF_AxisHints axis = &hints->axis[dim]; + AF_Segment segments = axis->segments; + AF_Segment segment_limit = FT_OFFSET( segments, axis->num_segments ); + FT_Error error; + AF_Segment seg; + + + error = af_latin_hints_compute_segments( hints, dim ); + if ( error ) + return error; + + /* a segment is round if it doesn't have successive */ + /* on-curve points. */ + for ( seg = segments; seg < segment_limit; seg++ ) + { + AF_Point pt = seg->first; + AF_Point last = seg->last; + FT_UInt f0 = pt->flags & AF_FLAG_CONTROL; + FT_UInt f1; + + + seg->flags &= ~AF_EDGE_ROUND; + + for ( ; pt != last; f0 = f1 ) + { + pt = pt->next; + f1 = pt->flags & AF_FLAG_CONTROL; + + if ( !f0 && !f1 ) + break; + + if ( pt == last ) + seg->flags |= AF_EDGE_ROUND; + } + } + + return FT_Err_Ok; + } + + + static void + af_cjk_hints_link_segments( AF_GlyphHints hints, + AF_Dimension dim ) + { + AF_AxisHints axis = &hints->axis[dim]; + AF_Segment segments = axis->segments; + AF_Segment segment_limit = FT_OFFSET( segments, axis->num_segments ); + AF_Direction major_dir = axis->major_dir; + AF_Segment seg1, seg2; + FT_Pos len_threshold; + FT_Pos dist_threshold; + + + len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 ); + + dist_threshold = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale + : hints->y_scale; + dist_threshold = FT_DivFix( 64 * 3, dist_threshold ); + + /* now compare each segment to the others */ + for ( seg1 = segments; seg1 < segment_limit; seg1++ ) + { + if ( seg1->dir != major_dir ) + continue; + + for ( seg2 = segments; seg2 < segment_limit; seg2++ ) + if ( seg2 != seg1 && seg1->dir + seg2->dir == 0 ) + { + FT_Pos dist = seg2->pos - seg1->pos; + + + if ( dist < 0 ) + continue; + + { + FT_Pos min = seg1->min_coord; + FT_Pos max = seg1->max_coord; + FT_Pos len; + + + if ( min < seg2->min_coord ) + min = seg2->min_coord; + + if ( max > seg2->max_coord ) + max = seg2->max_coord; + + len = max - min; + if ( len >= len_threshold ) + { + if ( dist * 8 < seg1->score * 9 && + ( dist * 8 < seg1->score * 7 || seg1->len < len ) ) + { + seg1->score = dist; + seg1->len = len; + seg1->link = seg2; + } + + if ( dist * 8 < seg2->score * 9 && + ( dist * 8 < seg2->score * 7 || seg2->len < len ) ) + { + seg2->score = dist; + seg2->len = len; + seg2->link = seg1; + } + } + } + } + } + + /* + * now compute the `serif' segments + * + * In Hanzi, some strokes are wider on one or both of the ends. + * We either identify the stems on the ends as serifs or remove + * the linkage, depending on the length of the stems. + * + */ + + { + AF_Segment link1, link2; + + + for ( seg1 = segments; seg1 < segment_limit; seg1++ ) + { + link1 = seg1->link; + if ( !link1 || link1->link != seg1 || link1->pos <= seg1->pos ) + continue; + + if ( seg1->score >= dist_threshold ) + continue; + + for ( seg2 = segments; seg2 < segment_limit; seg2++ ) + { + if ( seg2->pos > seg1->pos || seg1 == seg2 ) + continue; + + link2 = seg2->link; + if ( !link2 || link2->link != seg2 || link2->pos < link1->pos ) + continue; + + if ( seg1->pos == seg2->pos && link1->pos == link2->pos ) + continue; + + if ( seg2->score <= seg1->score || seg1->score * 4 <= seg2->score ) + continue; + + /* seg2 < seg1 < link1 < link2 */ + + if ( seg1->len >= seg2->len * 3 ) + { + AF_Segment seg; + + + for ( seg = segments; seg < segment_limit; seg++ ) + { + AF_Segment link = seg->link; + + + if ( link == seg2 ) + { + seg->link = NULL; + seg->serif = link1; + } + else if ( link == link2 ) + { + seg->link = NULL; + seg->serif = seg1; + } + } + } + else + { + seg1->link = link1->link = NULL; + + break; + } + } + } + } + + for ( seg1 = segments; seg1 < segment_limit; seg1++ ) + { + seg2 = seg1->link; + + if ( seg2 ) + { + if ( seg2->link != seg1 ) + { + seg1->link = NULL; + + if ( seg2->score < dist_threshold || seg1->score < seg2->score * 4 ) + seg1->serif = seg2->link; + } + } + } + } + + + static FT_Error + af_cjk_hints_compute_edges( AF_GlyphHints hints, + AF_Dimension dim ) + { + AF_AxisHints axis = &hints->axis[dim]; + FT_Error error = FT_Err_Ok; + FT_Memory memory = hints->memory; + AF_CJKAxis laxis = &((AF_CJKMetrics)hints->metrics)->axis[dim]; + + AF_Segment segments = axis->segments; + AF_Segment segment_limit = FT_OFFSET( segments, axis->num_segments ); + AF_Segment seg; + + FT_Fixed scale; + FT_Pos edge_distance_threshold; + + + axis->num_edges = 0; + + scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale + : hints->y_scale; + + /********************************************************************** + * + * We begin by generating a sorted table of edges for the current + * direction. To do so, we simply scan each segment and try to find + * an edge in our table that corresponds to its position. + * + * If no edge is found, we create and insert a new edge in the + * sorted table. Otherwise, we simply add the segment to the edge's + * list which is then processed in the second step to compute the + * edge's properties. + * + * Note that the edges table is sorted along the segment/edge + * position. + * + */ + + edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold, + scale ); + if ( edge_distance_threshold > 64 / 4 ) + edge_distance_threshold = FT_DivFix( 64 / 4, scale ); + else + edge_distance_threshold = laxis->edge_distance_threshold; + + for ( seg = segments; seg < segment_limit; seg++ ) + { + AF_Edge found = NULL; + FT_Pos best = 0xFFFFU; + FT_UInt ee; + + + /* look for an edge corresponding to the segment */ + for ( ee = 0; ee < axis->num_edges; ee++ ) + { + AF_Edge edge = axis->edges + ee; + FT_Pos dist; + + + if ( edge->dir != seg->dir ) + continue; + + dist = seg->pos - edge->fpos; + if ( dist < 0 ) + dist = -dist; + + if ( dist < edge_distance_threshold && dist < best ) + { + AF_Segment link = seg->link; + + + /* check whether all linked segments of the candidate edge */ + /* can make a single edge. */ + if ( link ) + { + AF_Segment seg1 = edge->first; + FT_Pos dist2 = 0; + + + do + { + AF_Segment link1 = seg1->link; + + + if ( link1 ) + { + dist2 = AF_SEGMENT_DIST( link, link1 ); + if ( dist2 >= edge_distance_threshold ) + break; + } + + } while ( ( seg1 = seg1->edge_next ) != edge->first ); + + if ( dist2 >= edge_distance_threshold ) + continue; + } + + best = dist; + found = edge; + } + } + + if ( !found ) + { + AF_Edge edge; + + + /* insert a new edge in the list and */ + /* sort according to the position */ + error = af_axis_hints_new_edge( axis, seg->pos, + (AF_Direction)seg->dir, 0, + memory, &edge ); + if ( error ) + goto Exit; + + /* add the segment to the new edge's list */ + FT_ZERO( edge ); + + edge->first = seg; + edge->last = seg; + edge->dir = seg->dir; + edge->fpos = seg->pos; + edge->opos = FT_MulFix( seg->pos, scale ); + edge->pos = edge->opos; + seg->edge_next = seg; + } + else + { + /* if an edge was found, simply add the segment to the edge's */ + /* list */ + seg->edge_next = found->first; + found->last->edge_next = seg; + found->last = seg; + } + } + + /******************************************************************* + * + * Good, we now compute each edge's properties according to the + * segments found on its position. Basically, these are + * + * - the edge's main direction + * - stem edge, serif edge or both (which defaults to stem then) + * - rounded edge, straight or both (which defaults to straight) + * - link for edge + * + */ + + /* first of all, set the `edge' field in each segment -- this is */ + /* required in order to compute edge links */ + + /* + * Note that removing this loop and setting the `edge' field of each + * segment directly in the code above slows down execution speed for + * some reasons on platforms like the Sun. + */ + { + AF_Edge edges = axis->edges; + AF_Edge edge_limit = FT_OFFSET( edges, axis->num_edges ); + AF_Edge edge; + + + for ( edge = edges; edge < edge_limit; edge++ ) + { + seg = edge->first; + if ( seg ) + do + { + seg->edge = edge; + seg = seg->edge_next; + + } while ( seg != edge->first ); + } + + /* now compute each edge properties */ + for ( edge = edges; edge < edge_limit; edge++ ) + { + FT_Int is_round = 0; /* does it contain round segments? */ + FT_Int is_straight = 0; /* does it contain straight segments? */ + + + seg = edge->first; + if ( !seg ) + goto Skip_Loop; + + do + { + FT_Bool is_serif; + + + /* check for roundness of segment */ + if ( seg->flags & AF_EDGE_ROUND ) + is_round++; + else + is_straight++; + + /* check for links -- if seg->serif is set, then seg->link must */ + /* be ignored */ + is_serif = FT_BOOL( seg->serif && seg->serif->edge != edge ); + + if ( seg->link || is_serif ) + { + AF_Edge edge2; + AF_Segment seg2; + + + edge2 = edge->link; + seg2 = seg->link; + + if ( is_serif ) + { + seg2 = seg->serif; + edge2 = edge->serif; + } + + if ( edge2 ) + { + FT_Pos edge_delta; + FT_Pos seg_delta; + + + edge_delta = edge->fpos - edge2->fpos; + if ( edge_delta < 0 ) + edge_delta = -edge_delta; + + seg_delta = AF_SEGMENT_DIST( seg, seg2 ); + + if ( seg_delta < edge_delta ) + edge2 = seg2->edge; + } + else + edge2 = seg2->edge; + + if ( is_serif ) + { + edge->serif = edge2; + edge2->flags |= AF_EDGE_SERIF; + } + else + edge->link = edge2; + } + + seg = seg->edge_next; + + } while ( seg != edge->first ); + + Skip_Loop: + /* set the round/straight flags */ + edge->flags = AF_EDGE_NORMAL; + + if ( is_round > 0 && is_round >= is_straight ) + edge->flags |= AF_EDGE_ROUND; + + /* get rid of serifs if link is set */ + /* XXX: This gets rid of many unpleasant artefacts! */ + /* Example: the `c' in cour.pfa at size 13 */ + + if ( edge->serif && edge->link ) + edge->serif = NULL; + } + } + + Exit: + return error; + } + + + /* Detect segments and edges for given dimension. */ + + static FT_Error + af_cjk_hints_detect_features( AF_GlyphHints hints, + AF_Dimension dim ) + { + FT_Error error; + + + error = af_cjk_hints_compute_segments( hints, dim ); + if ( !error ) + { + af_cjk_hints_link_segments( hints, dim ); + + error = af_cjk_hints_compute_edges( hints, dim ); + } + return error; + } + + + /* Compute all edges which lie within blue zones. */ + + static void + af_cjk_hints_compute_blue_edges( AF_GlyphHints hints, + AF_CJKMetrics metrics, + AF_Dimension dim ) + { + AF_AxisHints axis = &hints->axis[dim]; + AF_Edge edge = axis->edges; + AF_Edge edge_limit = FT_OFFSET( edge, axis->num_edges ); + AF_CJKAxis cjk = &metrics->axis[dim]; + FT_Fixed scale = cjk->scale; + FT_Pos best_dist0; /* initial threshold */ + + + /* compute the initial threshold as a fraction of the EM size */ + best_dist0 = FT_MulFix( metrics->units_per_em / 40, scale ); + + if ( best_dist0 > 64 / 2 ) /* maximum 1/2 pixel */ + best_dist0 = 64 / 2; + + /* compute which blue zones are active, i.e. have their scaled */ + /* size < 3/4 pixels */ + + /* If the distant between an edge and a blue zone is shorter than */ + /* best_dist0, set the blue zone for the edge. Then search for */ + /* the blue zone with the smallest best_dist to the edge. */ + + for ( ; edge < edge_limit; edge++ ) + { + FT_UInt bb; + AF_Width best_blue = NULL; + FT_Pos best_dist = best_dist0; + + + for ( bb = 0; bb < cjk->blue_count; bb++ ) + { + AF_CJKBlue blue = cjk->blues + bb; + FT_Bool is_top_right_blue, is_major_dir; + + + /* skip inactive blue zones (i.e., those that are too small) */ + if ( !( blue->flags & AF_CJK_BLUE_ACTIVE ) ) + continue; + + /* if it is a top zone, check for right edges -- if it is a bottom */ + /* zone, check for left edges */ + /* */ + /* of course, that's for TrueType */ + is_top_right_blue = + (FT_Byte)( ( blue->flags & AF_CJK_BLUE_TOP ) != 0 ); + is_major_dir = + FT_BOOL( edge->dir == axis->major_dir ); + + /* if it is a top zone, the edge must be against the major */ + /* direction; if it is a bottom zone, it must be in the major */ + /* direction */ + if ( is_top_right_blue ^ is_major_dir ) + { + FT_Pos dist; + AF_Width compare; + + + /* Compare the edge to the closest blue zone type */ + if ( FT_ABS( edge->fpos - blue->ref.org ) > + FT_ABS( edge->fpos - blue->shoot.org ) ) + compare = &blue->shoot; + else + compare = &blue->ref; + + dist = edge->fpos - compare->org; + if ( dist < 0 ) + dist = -dist; + + dist = FT_MulFix( dist, scale ); + if ( dist < best_dist ) + { + best_dist = dist; + best_blue = compare; + } + } + } + + if ( best_blue ) + edge->blue_edge = best_blue; + } + } + + + /* Initalize hinting engine. */ + + FT_LOCAL_DEF( FT_Error ) + af_cjk_hints_init( AF_GlyphHints hints, + AF_CJKMetrics metrics ) + { + FT_Render_Mode mode; + FT_UInt32 scaler_flags, other_flags; + + + af_glyph_hints_rescale( hints, (AF_StyleMetrics)metrics ); + + /* + * correct x_scale and y_scale when needed, since they may have + * been modified af_cjk_scale_dim above + */ + hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale; + hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta; + hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale; + hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta; + + /* compute flags depending on render mode, etc. */ + mode = metrics->root.scaler.render_mode; + + scaler_flags = hints->scaler_flags; + other_flags = 0; + + /* + * We snap the width of vertical stems for the monochrome and + * horizontal LCD rendering targets only. + */ + if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD ) + other_flags |= AF_LATIN_HINTS_HORZ_SNAP; + + /* + * We snap the width of horizontal stems for the monochrome and + * vertical LCD rendering targets only. + */ + if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V ) + other_flags |= AF_LATIN_HINTS_VERT_SNAP; + + /* + * We adjust stems to full pixels unless in `light' or `lcd' mode. + */ + if ( mode != FT_RENDER_MODE_LIGHT && mode != FT_RENDER_MODE_LCD ) + other_flags |= AF_LATIN_HINTS_STEM_ADJUST; + + if ( mode == FT_RENDER_MODE_MONO ) + other_flags |= AF_LATIN_HINTS_MONO; + + scaler_flags |= AF_SCALER_FLAG_NO_ADVANCE; + + hints->scaler_flags = scaler_flags; + hints->other_flags = other_flags; + + return FT_Err_Ok; + } + + + /*************************************************************************/ + /*************************************************************************/ + /***** *****/ + /***** C J K G L Y P H G R I D - F I T T I N G *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + + /* Snap a given width in scaled coordinates to one of the */ + /* current standard widths. */ + + static FT_Pos + af_cjk_snap_width( AF_Width widths, + FT_UInt count, + FT_Pos width ) + { + FT_UInt n; + FT_Pos best = 64 + 32 + 2; + FT_Pos reference = width; + FT_Pos scaled; + + + for ( n = 0; n < count; n++ ) + { + FT_Pos w; + FT_Pos dist; + + + w = widths[n].cur; + dist = width - w; + if ( dist < 0 ) + dist = -dist; + if ( dist < best ) + { + best = dist; + reference = w; + } + } + + scaled = FT_PIX_ROUND( reference ); + + if ( width >= reference ) + { + if ( width < scaled + 48 ) + width = reference; + } + else + { + if ( width > scaled - 48 ) + width = reference; + } + + return width; + } + + + /* Compute the snapped width of a given stem. */ + /* There is a lot of voodoo in this function; changing the hard-coded */ + /* parameters influence the whole hinting process. */ + + static FT_Pos + af_cjk_compute_stem_width( AF_GlyphHints hints, + AF_Dimension dim, + FT_Pos width, + FT_UInt base_flags, + FT_UInt stem_flags ) + { + AF_CJKMetrics metrics = (AF_CJKMetrics)hints->metrics; + AF_CJKAxis axis = &metrics->axis[dim]; + FT_Pos dist = width; + FT_Int sign = 0; + FT_Bool vertical = FT_BOOL( dim == AF_DIMENSION_VERT ); + + FT_UNUSED( base_flags ); + FT_UNUSED( stem_flags ); + + + if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) ) + return width; + + if ( dist < 0 ) + { + dist = -width; + sign = 1; + } + + if ( ( vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) || + ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) ) + { + /* smooth hinting process: very lightly quantize the stem width */ + + if ( axis->width_count > 0 ) + { + if ( FT_ABS( dist - axis->widths[0].cur ) < 40 ) + { + dist = axis->widths[0].cur; + if ( dist < 48 ) + dist = 48; + + goto Done_Width; + } + } + + if ( dist < 54 ) + dist += ( 54 - dist ) / 2; + else if ( dist < 3 * 64 ) + { + FT_Pos delta; + + + delta = dist & 63; + dist &= -64; + + if ( delta < 10 ) + dist += delta; + else if ( delta < 22 ) + dist += 10; + else if ( delta < 42 ) + dist += delta; + else if ( delta < 54 ) + dist += 54; + else + dist += delta; + } + } + else + { + /* strong hinting process: snap the stem width to integer pixels */ + + dist = af_cjk_snap_width( axis->widths, axis->width_count, dist ); + + if ( vertical ) + { + /* in the case of vertical hinting, always round */ + /* the stem heights to integer pixels */ + + if ( dist >= 64 ) + dist = ( dist + 16 ) & ~63; + else + dist = 64; + } + else + { + if ( AF_LATIN_HINTS_DO_MONO( hints ) ) + { + /* monochrome horizontal hinting: snap widths to integer pixels */ + /* with a different threshold */ + + if ( dist < 64 ) + dist = 64; + else + dist = ( dist + 32 ) & ~63; + } + else + { + /* for horizontal anti-aliased hinting, we adopt a more subtle */ + /* approach: we strengthen small stems, round stems whose size */ + /* is between 1 and 2 pixels to an integer, otherwise nothing */ + + if ( dist < 48 ) + dist = ( dist + 64 ) >> 1; + + else if ( dist < 128 ) + dist = ( dist + 22 ) & ~63; + else + /* round otherwise to prevent color fringes in LCD mode */ + dist = ( dist + 32 ) & ~63; + } + } + } + + Done_Width: + if ( sign ) + dist = -dist; + + return dist; + } + + + /* Align one stem edge relative to the previous stem edge. */ + + static void + af_cjk_align_linked_edge( AF_GlyphHints hints, + AF_Dimension dim, + AF_Edge base_edge, + AF_Edge stem_edge ) + { + FT_Pos dist = stem_edge->opos - base_edge->opos; + + FT_Pos fitted_width = af_cjk_compute_stem_width( hints, dim, dist, + base_edge->flags, + stem_edge->flags ); + + + stem_edge->pos = base_edge->pos + fitted_width; + + FT_TRACE5(( " CJKLINK: edge %ld @%d (opos=%.2f) linked to %.2f," + " dist was %.2f, now %.2f\n", + stem_edge - hints->axis[dim].edges, stem_edge->fpos, + (double)stem_edge->opos / 64, + (double)stem_edge->pos / 64, + (double)dist / 64, + (double)fitted_width / 64 )); + } + + + /* Shift the coordinates of the `serif' edge by the same amount */ + /* as the corresponding `base' edge has been moved already. */ + + static void + af_cjk_align_serif_edge( AF_GlyphHints hints, + AF_Edge base, + AF_Edge serif ) + { + FT_UNUSED( hints ); + + serif->pos = base->pos + ( serif->opos - base->opos ); + } + + + /*************************************************************************/ + /*************************************************************************/ + /*************************************************************************/ + /**** ****/ + /**** E D G E H I N T I N G ****/ + /**** ****/ + /*************************************************************************/ + /*************************************************************************/ + /*************************************************************************/ + + +#define AF_LIGHT_MODE_MAX_HORZ_GAP 9 +#define AF_LIGHT_MODE_MAX_VERT_GAP 15 +#define AF_LIGHT_MODE_MAX_DELTA_ABS 14 + + + static FT_Pos + af_hint_normal_stem( AF_GlyphHints hints, + AF_Edge edge, + AF_Edge edge2, + FT_Pos anchor, + AF_Dimension dim ) + { + FT_Pos org_len, cur_len, org_center; + FT_Pos cur_pos1, cur_pos2; + FT_Pos d_off1, u_off1, d_off2, u_off2, delta; + FT_Pos offset; + FT_Pos threshold = 64; + + + if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) ) + { + if ( ( edge->flags & AF_EDGE_ROUND ) && + ( edge2->flags & AF_EDGE_ROUND ) ) + { + if ( dim == AF_DIMENSION_VERT ) + threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP; + else + threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP; + } + else + { + if ( dim == AF_DIMENSION_VERT ) + threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP / 3; + else + threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP / 3; + } + } + + org_len = edge2->opos - edge->opos; + cur_len = af_cjk_compute_stem_width( hints, dim, org_len, + edge->flags, + edge2->flags ); + + org_center = ( edge->opos + edge2->opos ) / 2 + anchor; + cur_pos1 = org_center - cur_len / 2; + cur_pos2 = cur_pos1 + cur_len; + d_off1 = cur_pos1 - FT_PIX_FLOOR( cur_pos1 ); + d_off2 = cur_pos2 - FT_PIX_FLOOR( cur_pos2 ); + u_off1 = 64 - d_off1; + u_off2 = 64 - d_off2; + delta = 0; + + + if ( d_off1 == 0 || d_off2 == 0 ) + goto Exit; + + if ( cur_len <= threshold ) + { + if ( d_off2 < cur_len ) + { + if ( u_off1 <= d_off2 ) + delta = u_off1; + else + delta = -d_off2; + } + + goto Exit; + } + + if ( threshold < 64 ) + { + if ( d_off1 >= threshold || u_off1 >= threshold || + d_off2 >= threshold || u_off2 >= threshold ) + goto Exit; + } + + offset = cur_len & 63; + + if ( offset < 32 ) + { + if ( u_off1 <= offset || d_off2 <= offset ) + goto Exit; + } + else + offset = 64 - threshold; + + d_off1 = threshold - u_off1; + u_off1 = u_off1 - offset; + u_off2 = threshold - d_off2; + d_off2 = d_off2 - offset; + + if ( d_off1 <= u_off1 ) + u_off1 = -d_off1; + + if ( d_off2 <= u_off2 ) + u_off2 = -d_off2; + + if ( FT_ABS( u_off1 ) <= FT_ABS( u_off2 ) ) + delta = u_off1; + else + delta = u_off2; + + Exit: + +#if 1 + if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) ) + { + if ( delta > AF_LIGHT_MODE_MAX_DELTA_ABS ) + delta = AF_LIGHT_MODE_MAX_DELTA_ABS; + else if ( delta < -AF_LIGHT_MODE_MAX_DELTA_ABS ) + delta = -AF_LIGHT_MODE_MAX_DELTA_ABS; + } +#endif + + cur_pos1 += delta; + + if ( edge->opos < edge2->opos ) + { + edge->pos = cur_pos1; + edge2->pos = cur_pos1 + cur_len; + } + else + { + edge->pos = cur_pos1 + cur_len; + edge2->pos = cur_pos1; + } + + return delta; + } + + + /* The main grid-fitting routine. */ + + static void + af_cjk_hint_edges( AF_GlyphHints hints, + AF_Dimension dim ) + { + AF_AxisHints axis = &hints->axis[dim]; + AF_Edge edges = axis->edges; + AF_Edge edge_limit = FT_OFFSET( edges, axis->num_edges ); + FT_PtrDist n_edges; + AF_Edge edge; + AF_Edge anchor = NULL; + FT_Pos delta = 0; + FT_Int skipped = 0; + FT_Bool has_last_stem = FALSE; + FT_Pos last_stem_pos = 0; + +#ifdef FT_DEBUG_LEVEL_TRACE + FT_UInt num_actions = 0; +#endif + + + FT_TRACE5(( "cjk %s edge hinting (style `%s')\n", + dim == AF_DIMENSION_VERT ? "horizontal" : "vertical", + af_style_names[hints->metrics->style_class->style] )); + + /* we begin by aligning all stems relative to the blue zone */ + + if ( AF_HINTS_DO_BLUES( hints ) ) + { + for ( edge = edges; edge < edge_limit; edge++ ) + { + AF_Width blue; + AF_Edge edge1, edge2; + + + if ( edge->flags & AF_EDGE_DONE ) + continue; + + blue = edge->blue_edge; + edge1 = NULL; + edge2 = edge->link; + + if ( blue ) + { + edge1 = edge; + } + else if ( edge2 && edge2->blue_edge ) + { + blue = edge2->blue_edge; + edge1 = edge2; + edge2 = edge; + } + + if ( !edge1 ) + continue; + +#ifdef FT_DEBUG_LEVEL_TRACE + FT_TRACE5(( " CJKBLUE: edge %ld @%d (opos=%.2f) snapped to %.2f," + " was %.2f\n", + edge1 - edges, edge1->fpos, (double)edge1->opos / 64, + (double)blue->fit / 64, (double)edge1->pos / 64 )); + + num_actions++; +#endif + + edge1->pos = blue->fit; + edge1->flags |= AF_EDGE_DONE; + + if ( edge2 && !edge2->blue_edge ) + { + af_cjk_align_linked_edge( hints, dim, edge1, edge2 ); + edge2->flags |= AF_EDGE_DONE; + +#ifdef FT_DEBUG_LEVEL_TRACE + num_actions++; +#endif + } + + if ( !anchor ) + anchor = edge; + } + } + + /* now we align all stem edges. */ + for ( edge = edges; edge < edge_limit; edge++ ) + { + AF_Edge edge2; + + + if ( edge->flags & AF_EDGE_DONE ) + continue; + + /* skip all non-stem edges */ + edge2 = edge->link; + if ( !edge2 ) + { + skipped++; + continue; + } + + /* Some CJK characters have so many stems that + * the hinter is likely to merge two adjacent ones. + * To solve this problem, if either edge of a stem + * is too close to the previous one, we avoid + * aligning the two edges, but rather interpolate + * their locations at the end of this function in + * order to preserve the space between the stems. + */ + if ( has_last_stem && + ( edge->pos < last_stem_pos + 64 || + edge2->pos < last_stem_pos + 64 ) ) + { + skipped++; + continue; + } + + /* now align the stem */ + + /* this should not happen, but it's better to be safe */ + if ( edge2->blue_edge ) + { + FT_TRACE5(( "ASSERTION FAILED for edge %ld\n", edge2-edges )); + + af_cjk_align_linked_edge( hints, dim, edge2, edge ); + edge->flags |= AF_EDGE_DONE; + +#ifdef FT_DEBUG_LEVEL_TRACE + num_actions++; +#endif + + continue; + } + + if ( edge2 < edge ) + { + af_cjk_align_linked_edge( hints, dim, edge2, edge ); + edge->flags |= AF_EDGE_DONE; + +#ifdef FT_DEBUG_LEVEL_TRACE + num_actions++; +#endif + + /* We rarely reaches here it seems; + * usually the two edges belonging + * to one stem are marked as DONE together + */ + has_last_stem = TRUE; + last_stem_pos = edge->pos; + continue; + } + + if ( dim != AF_DIMENSION_VERT && !anchor ) + { + +#if 0 + if ( fixedpitch ) + { + AF_Edge left = edge; + AF_Edge right = edge_limit - 1; + AF_EdgeRec left1, left2, right1, right2; + FT_Pos target, center1, center2; + FT_Pos delta1, delta2, d1, d2; + + + while ( right > left && !right->link ) + right--; + + left1 = *left; + left2 = *left->link; + right1 = *right->link; + right2 = *right; + + delta = ( ( ( hinter->pp2.x + 32 ) & -64 ) - hinter->pp2.x ) / 2; + target = left->opos + ( right->opos - left->opos ) / 2 + delta - 16; + + delta1 = delta; + delta1 += af_hint_normal_stem( hints, left, left->link, + delta1, 0 ); + + if ( left->link != right ) + af_hint_normal_stem( hints, right->link, right, delta1, 0 ); + + center1 = left->pos + ( right->pos - left->pos ) / 2; + + if ( center1 >= target ) + delta2 = delta - 32; + else + delta2 = delta + 32; + + delta2 += af_hint_normal_stem( hints, &left1, &left2, delta2, 0 ); + + if ( delta1 != delta2 ) + { + if ( left->link != right ) + af_hint_normal_stem( hints, &right1, &right2, delta2, 0 ); + + center2 = left1.pos + ( right2.pos - left1.pos ) / 2; + + d1 = center1 - target; + d2 = center2 - target; + + if ( FT_ABS( d2 ) < FT_ABS( d1 ) ) + { + left->pos = left1.pos; + left->link->pos = left2.pos; + + if ( left->link != right ) + { + right->link->pos = right1.pos; + right->pos = right2.pos; + } + + delta1 = delta2; + } + } + + delta = delta1; + right->link->flags |= AF_EDGE_DONE; + right->flags |= AF_EDGE_DONE; + } + else + +#endif /* 0 */ + + delta = af_hint_normal_stem( hints, edge, edge2, 0, + AF_DIMENSION_HORZ ); + } + else + af_hint_normal_stem( hints, edge, edge2, delta, dim ); + +#if 0 + printf( "stem (%d,%d) adjusted (%.1f,%.1f)\n", + edge - edges, edge2 - edges, + (double)( edge->pos - edge->opos ) / 64, + (double)( edge2->pos - edge2->opos ) / 64 ); +#endif + + anchor = edge; + edge->flags |= AF_EDGE_DONE; + edge2->flags |= AF_EDGE_DONE; + has_last_stem = TRUE; + last_stem_pos = edge2->pos; + } + + /* make sure that lowercase m's maintain their symmetry */ + + /* In general, lowercase m's have six vertical edges if they are sans */ + /* serif, or twelve if they are with serifs. This implementation is */ + /* based on that assumption, and seems to work very well with most */ + /* faces. However, if for a certain face this assumption is not */ + /* true, the m is just rendered like before. In addition, any stem */ + /* correction will only be applied to symmetrical glyphs (even if the */ + /* glyph is not an m), so the potential for unwanted distortion is */ + /* relatively low. */ + + /* We don't handle horizontal edges since we can't easily assure that */ + /* the third (lowest) stem aligns with the base line; it might end up */ + /* one pixel higher or lower. */ + + n_edges = edge_limit - edges; + if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) ) + { + AF_Edge edge1, edge2, edge3; + FT_Pos dist1, dist2, span; + + + if ( n_edges == 6 ) + { + edge1 = edges; + edge2 = edges + 2; + edge3 = edges + 4; + } + else + { + edge1 = edges + 1; + edge2 = edges + 5; + edge3 = edges + 9; + } + + dist1 = edge2->opos - edge1->opos; + dist2 = edge3->opos - edge2->opos; + + span = dist1 - dist2; + if ( span < 0 ) + span = -span; + + if ( edge1->link == edge1 + 1 && + edge2->link == edge2 + 1 && + edge3->link == edge3 + 1 && span < 8 ) + { + delta = edge3->pos - ( 2 * edge2->pos - edge1->pos ); + edge3->pos -= delta; + if ( edge3->link ) + edge3->link->pos -= delta; + + /* move the serifs along with the stem */ + if ( n_edges == 12 ) + { + ( edges + 8 )->pos -= delta; + ( edges + 11 )->pos -= delta; + } + + edge3->flags |= AF_EDGE_DONE; + if ( edge3->link ) + edge3->link->flags |= AF_EDGE_DONE; + } + } + + if ( !skipped ) + goto Exit; + + /* + * now hint the remaining edges (serifs and single) in order + * to complete our processing + */ + for ( edge = edges; edge < edge_limit; edge++ ) + { + if ( edge->flags & AF_EDGE_DONE ) + continue; + + if ( edge->serif ) + { + af_cjk_align_serif_edge( hints, edge->serif, edge ); + edge->flags |= AF_EDGE_DONE; + skipped--; + } + } + + if ( !skipped ) + goto Exit; + + for ( edge = edges; edge < edge_limit; edge++ ) + { + AF_Edge before, after; + + + if ( edge->flags & AF_EDGE_DONE ) + continue; + + before = after = edge; + + while ( --before >= edges ) + if ( before->flags & AF_EDGE_DONE ) + break; + + while ( ++after < edge_limit ) + if ( after->flags & AF_EDGE_DONE ) + break; + + if ( before >= edges || after < edge_limit ) + { + if ( before < edges ) + af_cjk_align_serif_edge( hints, after, edge ); + else if ( after >= edge_limit ) + af_cjk_align_serif_edge( hints, before, edge ); + else + { + if ( after->fpos == before->fpos ) + edge->pos = before->pos; + else + edge->pos = before->pos + + FT_MulDiv( edge->fpos - before->fpos, + after->pos - before->pos, + after->fpos - before->fpos ); + } + } + } + + Exit: + +#ifdef FT_DEBUG_LEVEL_TRACE + if ( !num_actions ) + FT_TRACE5(( " (none)\n" )); + FT_TRACE5(( "\n" )); +#endif + + return; + } + + + static void + af_cjk_align_edge_points( AF_GlyphHints hints, + AF_Dimension dim ) + { + AF_AxisHints axis = & hints->axis[dim]; + AF_Edge edges = axis->edges; + AF_Edge edge_limit = FT_OFFSET( edges, axis->num_edges ); + AF_Edge edge; + FT_Bool snapping; + + + snapping = FT_BOOL( ( dim == AF_DIMENSION_HORZ && + AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) || + ( dim == AF_DIMENSION_VERT && + AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) ); + + for ( edge = edges; edge < edge_limit; edge++ ) + { + /* move the points of each segment */ + /* in each edge to the edge's position */ + AF_Segment seg = edge->first; + + + if ( snapping ) + { + do + { + AF_Point point = seg->first; + + + for (;;) + { + if ( dim == AF_DIMENSION_HORZ ) + { + point->x = edge->pos; + point->flags |= AF_FLAG_TOUCH_X; + } + else + { + point->y = edge->pos; + point->flags |= AF_FLAG_TOUCH_Y; + } + + if ( point == seg->last ) + break; + + point = point->next; + } + + seg = seg->edge_next; + + } while ( seg != edge->first ); + } + else + { + FT_Pos delta = edge->pos - edge->opos; + + + do + { + AF_Point point = seg->first; + + + for (;;) + { + if ( dim == AF_DIMENSION_HORZ ) + { + point->x += delta; + point->flags |= AF_FLAG_TOUCH_X; + } + else + { + point->y += delta; + point->flags |= AF_FLAG_TOUCH_Y; + } + + if ( point == seg->last ) + break; + + point = point->next; + } + + seg = seg->edge_next; + + } while ( seg != edge->first ); + } + } + } + + + /* Apply the complete hinting algorithm to a CJK glyph. */ + + FT_LOCAL_DEF( FT_Error ) + af_cjk_hints_apply( FT_UInt glyph_index, + AF_GlyphHints hints, + FT_Outline* outline, + AF_CJKMetrics metrics ) + { + FT_Error error; + int dim; + + FT_UNUSED( metrics ); + FT_UNUSED( glyph_index ); + + + error = af_glyph_hints_reload( hints, outline ); + if ( error ) + goto Exit; + + /* analyze glyph outline */ + if ( AF_HINTS_DO_HORIZONTAL( hints ) ) + { + error = af_cjk_hints_detect_features( hints, AF_DIMENSION_HORZ ); + if ( error ) + goto Exit; + + af_cjk_hints_compute_blue_edges( hints, metrics, AF_DIMENSION_HORZ ); + } + + if ( AF_HINTS_DO_VERTICAL( hints ) ) + { + error = af_cjk_hints_detect_features( hints, AF_DIMENSION_VERT ); + if ( error ) + goto Exit; + + af_cjk_hints_compute_blue_edges( hints, metrics, AF_DIMENSION_VERT ); + } + + /* grid-fit the outline */ + for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) + { + if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) || + ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) ) ) + { + af_cjk_hint_edges( hints, (AF_Dimension)dim ); + af_cjk_align_edge_points( hints, (AF_Dimension)dim ); + af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim ); + af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim ); + } + } + + af_glyph_hints_save( hints, outline ); + + Exit: + return error; + } + + + /*************************************************************************/ + /*************************************************************************/ + /***** *****/ + /***** C J K S C R I P T C L A S S *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + + + AF_DEFINE_WRITING_SYSTEM_CLASS( + af_cjk_writing_system_class, + + AF_WRITING_SYSTEM_CJK, + + sizeof ( AF_CJKMetricsRec ), + + (AF_WritingSystem_InitMetricsFunc) af_cjk_metrics_init, /* style_metrics_init */ + (AF_WritingSystem_ScaleMetricsFunc)af_cjk_metrics_scale, /* style_metrics_scale */ + (AF_WritingSystem_DoneMetricsFunc) NULL, /* style_metrics_done */ + (AF_WritingSystem_GetStdWidthsFunc)af_cjk_get_standard_widths, /* style_metrics_getstdw */ + + (AF_WritingSystem_InitHintsFunc) af_cjk_hints_init, /* style_hints_init */ + (AF_WritingSystem_ApplyHintsFunc) af_cjk_hints_apply /* style_hints_apply */ + ) + + +#else /* !AF_CONFIG_OPTION_CJK */ + + + AF_DEFINE_WRITING_SYSTEM_CLASS( + af_cjk_writing_system_class, + + AF_WRITING_SYSTEM_CJK, + + sizeof ( AF_CJKMetricsRec ), + + (AF_WritingSystem_InitMetricsFunc) NULL, /* style_metrics_init */ + (AF_WritingSystem_ScaleMetricsFunc)NULL, /* style_metrics_scale */ + (AF_WritingSystem_DoneMetricsFunc) NULL, /* style_metrics_done */ + (AF_WritingSystem_GetStdWidthsFunc)NULL, /* style_metrics_getstdw */ + + (AF_WritingSystem_InitHintsFunc) NULL, /* style_hints_init */ + (AF_WritingSystem_ApplyHintsFunc) NULL /* style_hints_apply */ + ) + + +#endif /* !AF_CONFIG_OPTION_CJK */ + + +/* END */ |