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kc3-lang/freetype/src/autofit/afcjk.c
Werner Lemberg
- src/autofit/afcjk.c
-
/**************************************************************************** * * afcjk.c * * Auto-fitter hinting routines for CJK writing system (body). * * Copyright (C) 2006-2020 by * David Turner, Robert Wilhelm, and Werner Lemberg. * * This file is part of the FreeType project, and may only be used, * modified, and distributed under the terms of the FreeType project * license, LICENSE.TXT. By continuing to use, modify, or distribute * this file you indicate that you have read the license and * understand and accept it fully. * */ /* * 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" #ifdef AF_CONFIG_OPTION_USE_WARPER #include "afwarp.h" #endif /************************************************************************** * * The macro FT_COMPONENT is used in trace mode. It is an implicit * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log * messages during execution. */ #undef FT_COMPONENT #define FT_COMPONENT 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" "cjk standard widths computation (style `%s')\n" "===================================================\n" "\n", af_style_names[metrics->root.style_class->style] )); af_glyph_hints_init( hints, face->memory ); metrics->axis[AF_DIMENSION_HORZ].width_count = 0; metrics->axis[AF_DIMENSION_VERT].width_count = 0; { FT_Error error; FT_ULong glyph_index; 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 %d)\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(( " %d (standard)", axis->standard_width )); for ( i = 1; i < axis->width_count; i++ ) FT_TRACE5(( " %d", axis->widths[i].org )); FT_TRACE5(( "\n" )); } #endif } } FT_TRACE5(( "\n" )); af_glyph_hints_done( hints ); } /* Find all blue zones. */ 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" "==========================\n" "\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" " overshoot = %ld\n", *blue_ref, *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 ); } FT_Set_Charmap( face, oldmap ); return FT_Err_Ok; } /* Adjust scaling value, then scale and shift widths */ /* and blue zones (if applicable) for given dimension. */ static void af_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: %d", 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(( "/%d\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" " ref: cur=%.2f fit=%.2f\n" " shoot: cur=%.2f fit=%.2f\n", ( dim == AF_DIMENSION_HORZ ) ? 'H' : 'V', nn, blue->ref.org, blue->shoot.org, blue->ref.cur / 64.0, blue->ref.fit / 64.0, blue->shoot.cur / 64.0, blue->shoot.fit / 64.0 )); 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 = 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 = 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_Int 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 = 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 = 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; #if 0 /* AF_CONFIG_OPTION_USE_WARPER */ if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V ) metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL; #endif scaler_flags = hints->scaler_flags; other_flags = 0; /* * We snap the width of vertical stems for the monochrome and * horizontal LCD rendering targets only. */ if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD ) other_flags |= AF_LATIN_HINTS_HORZ_SNAP; /* * We snap the width of horizontal stems for the monochrome and * vertical LCD rendering targets only. */ if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V ) other_flags |= AF_LATIN_HINTS_VERT_SNAP; /* * We adjust stems to full pixels unless in `light' or `lcd' mode. */ if ( mode != FT_RENDER_MODE_LIGHT && mode != FT_RENDER_MODE_LCD ) other_flags |= AF_LATIN_HINTS_STEM_ADJUST; if ( mode == FT_RENDER_MODE_MONO ) other_flags |= AF_LATIN_HINTS_MONO; scaler_flags |= AF_SCALER_FLAG_NO_ADVANCE; #ifdef AF_CONFIG_OPTION_USE_WARPER /* get (global) warper flag */ if ( !metrics->root.globals->module->warping ) scaler_flags |= AF_SCALER_FLAG_NO_WARPER; #endif hints->scaler_flags = scaler_flags; hints->other_flags = other_flags; return FT_Err_Ok; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** 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 %d @%d (opos=%.2f) linked to %.2f," " dist was %.2f, now %.2f\n", stem_edge - hints->axis[dim].edges, stem_edge->fpos, stem_edge->opos / 64.0, stem_edge->pos / 64.0, dist / 64.0, fitted_width / 64.0 )); } /* Shift the coordinates of the `serif' edge by the same amount */ /* as the corresponding `base' edge has been moved already. */ static void af_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 = 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 %d @%d (opos=%.2f) snapped to %.2f," " was %.2f\n", edge1 - edges, edge1->fpos, edge1->opos / 64.0, blue->fit / 64.0, edge1->pos / 64.0 )); num_actions++; #endif edge1->pos = blue->fit; edge1->flags |= AF_EDGE_DONE; if ( edge2 && !edge2->blue_edge ) { af_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 %d\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, ( edge->pos - edge->opos ) / 64.0, ( edge2->pos - edge2->opos ) / 64.0 ); #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 = 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 ) ) ) { #ifdef AF_CONFIG_OPTION_USE_WARPER if ( dim == AF_DIMENSION_HORZ && metrics->root.scaler.render_mode == FT_RENDER_MODE_NORMAL && AF_HINTS_DO_WARP( hints ) ) { AF_WarperRec warper; FT_Fixed scale; FT_Pos delta; af_warper_compute( &warper, hints, (AF_Dimension)dim, &scale, &delta ); af_glyph_hints_scale_dim( hints, (AF_Dimension)dim, scale, delta ); continue; } #endif /* AF_CONFIG_OPTION_USE_WARPER */ 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 */