| /**************************************************************************** |
| * |
| * aflatin.c |
| * |
| * Auto-fitter hinting routines for latin writing system (body). |
| * |
| * Copyright (C) 2003-2022 by |
| * David Turner, Robert Wilhelm, and Werner Lemberg. |
| * |
| * This file is part of the FreeType project, and may only be used, |
| * modified, and distributed under the terms of the FreeType project |
| * license, LICENSE.TXT. By continuing to use, modify, or distribute |
| * this file you indicate that you have read the license and |
| * understand and accept it fully. |
| * |
| */ |
| |
| |
| #include <freetype/ftadvanc.h> |
| #include <freetype/internal/ftdebug.h> |
| |
| #include "afglobal.h" |
| #include "aflatin.h" |
| #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 aflatin |
| |
| |
| /* needed for computation of round vs. flat segments */ |
| #define FLAT_THRESHOLD( x ) ( x / 14 ) |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /***** *****/ |
| /***** L A T I N G L O B A L M E T R I C S *****/ |
| /***** *****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| /* Find segments and links, compute all stem widths, and initialize */ |
| /* standard width and height for the glyph with given charcode. */ |
| |
| FT_LOCAL_DEF( void ) |
| af_latin_metrics_init_widths( AF_LatinMetrics metrics, |
| FT_Face face ) |
| { |
| /* scan the array of segments in each direction */ |
| AF_GlyphHintsRec hints[1]; |
| |
| |
| FT_TRACE5(( "\n" )); |
| FT_TRACE5(( "latin 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_LatinMetricsRec 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 to catch features like |
| * `c2sc' (small caps from caps) that don't contain lowercase letters |
| * by definition, or other features that mainly operate on numerals. |
| * 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 ) |
| { |
| FT_TRACE5(( "standard character missing;" |
| " using fallback stem widths\n" )); |
| 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_LatinAxis axis = &metrics->axis[dim]; |
| AF_AxisHints axhints = &hints->axis[dim]; |
| AF_Segment seg, limit, link; |
| FT_UInt num_widths = 0; |
| |
| |
| error = af_latin_hints_compute_segments( hints, |
| (AF_Dimension)dim ); |
| if ( error ) |
| goto Exit; |
| |
| /* |
| * We assume that the glyphs selected for the stem width |
| * computation are `featureless' enough so that the linking |
| * algorithm works fine without adjustments of its scoring |
| * function. |
| */ |
| af_latin_hints_link_segments( hints, |
| 0, |
| NULL, |
| (AF_Dimension)dim ); |
| |
| seg = axhints->segments; |
| limit = FT_OFFSET( seg, axhints->num_segments ); |
| |
| for ( ; seg < limit; seg++ ) |
| { |
| link = seg->link; |
| |
| /* we only consider stem segments there! */ |
| if ( link && link->link == seg && link > seg ) |
| { |
| FT_Pos dist; |
| |
| |
| dist = seg->pos - link->pos; |
| if ( dist < 0 ) |
| dist = -dist; |
| |
| if ( num_widths < AF_LATIN_MAX_WIDTHS ) |
| axis->widths[num_widths++].org = dist; |
| } |
| } |
| |
| /* this also replaces multiple almost identical stem widths */ |
| /* with a single one (the value 100 is heuristic) */ |
| af_sort_and_quantize_widths( &num_widths, axis->widths, |
| dummy->units_per_em / 100 ); |
| axis->width_count = num_widths; |
| } |
| |
| Exit: |
| for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) |
| { |
| AF_LatinAxis axis = &metrics->axis[dim]; |
| FT_Pos stdw; |
| |
| |
| stdw = ( axis->width_count > 0 ) ? axis->widths[0].org |
| : AF_LATIN_CONSTANT( metrics, 50 ); |
| |
| /* let's try 20% of the smallest width */ |
| axis->edge_distance_threshold = stdw / 5; |
| axis->standard_width = stdw; |
| axis->extra_light = 0; |
| |
| #ifdef FT_DEBUG_LEVEL_TRACE |
| { |
| FT_UInt i; |
| |
| |
| FT_TRACE5(( "%s widths:\n", |
| dim == AF_DIMENSION_VERT ? "horizontal" |
| : "vertical" )); |
| |
| FT_TRACE5(( " %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 ); |
| } |
| |
| |
| static void |
| af_latin_sort_blue( FT_UInt count, |
| AF_LatinBlue* table ) |
| { |
| FT_UInt i, j; |
| AF_LatinBlue swap; |
| |
| |
| /* we sort from bottom to top */ |
| for ( i = 1; i < count; i++ ) |
| { |
| for ( j = i; j > 0; j-- ) |
| { |
| FT_Pos a, b; |
| |
| |
| if ( table[j - 1]->flags & ( AF_LATIN_BLUE_TOP | |
| AF_LATIN_BLUE_SUB_TOP ) ) |
| a = table[j - 1]->ref.org; |
| else |
| a = table[j - 1]->shoot.org; |
| |
| if ( table[j]->flags & ( AF_LATIN_BLUE_TOP | |
| AF_LATIN_BLUE_SUB_TOP ) ) |
| b = table[j]->ref.org; |
| else |
| b = table[j]->shoot.org; |
| |
| if ( b >= a ) |
| break; |
| |
| swap = table[j]; |
| table[j] = table[j - 1]; |
| table[j - 1] = swap; |
| } |
| } |
| } |
| |
| |
| /* Find all blue zones. Flat segments give the reference points, */ |
| /* round segments the overshoot positions. */ |
| |
| static int |
| af_latin_metrics_init_blues( AF_LatinMetrics metrics, |
| FT_Face face ) |
| { |
| FT_Pos flats [AF_BLUE_STRING_MAX_LEN]; |
| FT_Pos rounds[AF_BLUE_STRING_MAX_LEN]; |
| |
| FT_UInt num_flats; |
| FT_UInt num_rounds; |
| |
| AF_LatinBlue blue; |
| FT_Error error; |
| AF_LatinAxis axis = &metrics->axis[AF_DIMENSION_VERT]; |
| FT_Outline outline; |
| |
| AF_StyleClass sc = metrics->root.style_class; |
| |
| AF_Blue_Stringset bss = sc->blue_stringset; |
| const AF_Blue_StringRec* bs = &af_blue_stringsets[bss]; |
| |
| FT_Pos flat_threshold = FLAT_THRESHOLD( metrics->units_per_em ); |
| |
| /* 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 */ |
| |
| FT_TRACE5(( "latin 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; |
| FT_Pos ascender; |
| FT_Pos descender; |
| |
| |
| #ifdef FT_DEBUG_LEVEL_TRACE |
| { |
| FT_Bool have_flag = 0; |
| |
| |
| FT_TRACE5(( "blue zone %d", axis->blue_count )); |
| |
| if ( bs->properties ) |
| { |
| FT_TRACE5(( " (" )); |
| |
| if ( AF_LATIN_IS_TOP_BLUE( bs ) ) |
| { |
| FT_TRACE5(( "top" )); |
| have_flag = 1; |
| } |
| else if ( AF_LATIN_IS_SUB_TOP_BLUE( bs ) ) |
| { |
| FT_TRACE5(( "sub top" )); |
| have_flag = 1; |
| } |
| |
| if ( AF_LATIN_IS_NEUTRAL_BLUE( bs ) ) |
| { |
| if ( have_flag ) |
| FT_TRACE5(( ", " )); |
| FT_TRACE5(( "neutral" )); |
| have_flag = 1; |
| } |
| |
| if ( AF_LATIN_IS_X_HEIGHT_BLUE( bs ) ) |
| { |
| if ( have_flag ) |
| FT_TRACE5(( ", " )); |
| FT_TRACE5(( "small top" )); |
| have_flag = 1; |
| } |
| |
| if ( AF_LATIN_IS_LONG_BLUE( bs ) ) |
| { |
| if ( have_flag ) |
| FT_TRACE5(( ", " )); |
| FT_TRACE5(( "long" )); |
| } |
| |
| FT_TRACE5(( ")" )); |
| } |
| |
| FT_TRACE5(( ":\n" )); |
| } |
| #endif /* FT_DEBUG_LEVEL_TRACE */ |
| |
| num_flats = 0; |
| num_rounds = 0; |
| ascender = 0; |
| descender = 0; |
| |
| while ( *p ) |
| { |
| FT_ULong glyph_index; |
| FT_Long y_offset; |
| FT_Int best_point, best_contour_first, best_contour_last; |
| FT_Vector* points; |
| |
| FT_Pos best_y_extremum; /* same as points.y */ |
| FT_Bool best_round = 0; |
| |
| unsigned int i, 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 |
| |
| p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx ); |
| |
| if ( !num_idx ) |
| { |
| FT_TRACE5(( " U+%04lX unavailable\n", ch )); |
| continue; |
| } |
| |
| if ( AF_LATIN_IS_TOP_BLUE( bs ) ) |
| best_y_extremum = FT_INT_MIN; |
| else |
| best_y_extremum = FT_INT_MAX; |
| |
| /* iterate over all glyph elements of the character cluster */ |
| /* and get the data of the `biggest' one */ |
| for ( i = 0; i < num_idx; i++ ) |
| { |
| FT_Pos best_y; |
| FT_Bool round = 0; |
| |
| |
| /* load the character in the face -- skip unknown or empty ones */ |
| glyph_index = af_shaper_get_elem( &metrics->root, |
| shaper_buf, |
| i, |
| NULL, |
| &y_offset ); |
| if ( glyph_index == 0 ) |
| { |
| FT_TRACE5(( " U+%04lX unavailable\n", ch )); |
| continue; |
| } |
| |
| error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); |
| outline = face->glyph->outline; |
| /* reject glyphs that don't produce any rendering */ |
| if ( error || outline.n_points <= 2 ) |
| { |
| #ifdef FT_DEBUG_LEVEL_TRACE |
| if ( num_idx == 1 ) |
| FT_TRACE5(( " U+%04lX contains no (usable) outlines\n", ch )); |
| else |
| FT_TRACE5(( " component %d of cluster starting with U+%04lX" |
| " contains no (usable) outlines\n", i, ch )); |
| #endif |
| continue; |
| } |
| |
| /* now compute min or max point indices and coordinates */ |
| points = outline.points; |
| best_point = -1; |
| best_y = 0; /* make compiler happy */ |
| best_contour_first = 0; /* ditto */ |
| best_contour_last = 0; /* ditto */ |
| |
| { |
| FT_Int nn; |
| FT_Int first = 0; |
| FT_Int last = -1; |
| |
| |
| for ( nn = 0; nn < outline.n_contours; first = last + 1, nn++ ) |
| { |
| FT_Int old_best_point = best_point; |
| FT_Int pp; |
| |
| |
| last = outline.contours[nn]; |
| |
| /* Avoid single-point contours since they are never */ |
| /* rasterized. In some fonts, they correspond to mark */ |
| /* attachment points that are way outside of the glyph's */ |
| /* real outline. */ |
| if ( last <= first ) |
| continue; |
| |
| if ( AF_LATIN_IS_TOP_BLUE( bs ) || |
| AF_LATIN_IS_SUB_TOP_BLUE( bs ) ) |
| { |
| for ( pp = first; pp <= last; pp++ ) |
| { |
| if ( best_point < 0 || points[pp].y > best_y ) |
| { |
| best_point = pp; |
| best_y = points[pp].y; |
| ascender = FT_MAX( ascender, best_y + y_offset ); |
| } |
| else |
| descender = FT_MIN( descender, points[pp].y + y_offset ); |
| } |
| } |
| else |
| { |
| for ( pp = first; pp <= last; pp++ ) |
| { |
| if ( best_point < 0 || points[pp].y < best_y ) |
| { |
| best_point = pp; |
| best_y = points[pp].y; |
| descender = FT_MIN( descender, best_y + y_offset ); |
| } |
| else |
| ascender = FT_MAX( ascender, points[pp].y + y_offset ); |
| } |
| } |
| |
| if ( best_point != old_best_point ) |
| { |
| best_contour_first = first; |
| best_contour_last = last; |
| } |
| } |
| } |
| |
| /* now check whether the point belongs to a straight or round */ |
| /* segment; we first need to find in which contour the extremum */ |
| /* lies, then inspect its previous and next points */ |
| if ( best_point >= 0 ) |
| { |
| FT_Pos best_x = points[best_point].x; |
| FT_Int prev, next; |
| FT_Int best_segment_first, best_segment_last; |
| FT_Int best_on_point_first, best_on_point_last; |
| FT_Pos dist; |
| |
| |
| best_segment_first = best_point; |
| best_segment_last = best_point; |
| |
| if ( FT_CURVE_TAG( outline.tags[best_point] ) == FT_CURVE_TAG_ON ) |
| { |
| best_on_point_first = best_point; |
| best_on_point_last = best_point; |
| } |
| else |
| { |
| best_on_point_first = -1; |
| best_on_point_last = -1; |
| } |
| |
| /* look for the previous and next points on the contour */ |
| /* that are not on the same Y coordinate, then threshold */ |
| /* the `closeness'... */ |
| prev = best_point; |
| next = prev; |
| |
| do |
| { |
| if ( prev > best_contour_first ) |
| prev--; |
| else |
| prev = best_contour_last; |
| |
| dist = FT_ABS( points[prev].y - best_y ); |
| /* accept a small distance or a small angle (both values are */ |
| /* heuristic; value 20 corresponds to approx. 2.9 degrees) */ |
| if ( dist > 5 ) |
| if ( FT_ABS( points[prev].x - best_x ) <= 20 * dist ) |
| break; |
| |
| best_segment_first = prev; |
| |
| if ( FT_CURVE_TAG( outline.tags[prev] ) == FT_CURVE_TAG_ON ) |
| { |
| best_on_point_first = prev; |
| if ( best_on_point_last < 0 ) |
| best_on_point_last = prev; |
| } |
| |
| } while ( prev != best_point ); |
| |
| do |
| { |
| if ( next < best_contour_last ) |
| next++; |
| else |
| next = best_contour_first; |
| |
| dist = FT_ABS( points[next].y - best_y ); |
| if ( dist > 5 ) |
| if ( FT_ABS( points[next].x - best_x ) <= 20 * dist ) |
| break; |
| |
| best_segment_last = next; |
| |
| if ( FT_CURVE_TAG( outline.tags[next] ) == FT_CURVE_TAG_ON ) |
| { |
| best_on_point_last = next; |
| if ( best_on_point_first < 0 ) |
| best_on_point_first = next; |
| } |
| |
| } while ( next != best_point ); |
| |
| if ( AF_LATIN_IS_LONG_BLUE( bs ) ) |
| { |
| /* If this flag is set, we have an additional constraint to */ |
| /* get the blue zone distance: Find a segment of the topmost */ |
| /* (or bottommost) contour that is longer than a heuristic */ |
| /* threshold. This ensures that small bumps in the outline */ |
| /* are ignored (for example, the `vertical serifs' found in */ |
| /* many Hebrew glyph designs). */ |
| |
| /* If this segment is long enough, we are done. Otherwise, */ |
| /* search the segment next to the extremum that is long */ |
| /* enough, has the same direction, and a not too large */ |
| /* vertical distance from the extremum. Note that the */ |
| /* algorithm doesn't check whether the found segment is */ |
| /* actually the one (vertically) nearest to the extremum. */ |
| |
| /* heuristic threshold value */ |
| FT_Pos length_threshold = metrics->units_per_em / 25; |
| |
| |
| dist = FT_ABS( points[best_segment_last].x - |
| points[best_segment_first].x ); |
| |
| if ( dist < length_threshold && |
| best_segment_last - best_segment_first + 2 <= |
| best_contour_last - best_contour_first ) |
| { |
| /* heuristic threshold value */ |
| FT_Pos height_threshold = metrics->units_per_em / 4; |
| |
| FT_Int first; |
| FT_Int last; |
| FT_Bool hit; |
| |
| /* we intentionally declare these two variables */ |
| /* outside of the loop since various compilers emit */ |
| /* incorrect warning messages otherwise, talking about */ |
| /* `possibly uninitialized variables' */ |
| FT_Int p_first = 0; /* make compiler happy */ |
| FT_Int p_last = 0; |
| |
| FT_Bool left2right; |
| |
| |
| /* compute direction */ |
| prev = best_point; |
| |
| do |
| { |
| if ( prev > best_contour_first ) |
| prev--; |
| else |
| prev = best_contour_last; |
| |
| if ( points[prev].x != best_x ) |
| break; |
| |
| } while ( prev != best_point ); |
| |
| /* skip glyph for the degenerate case */ |
| if ( prev == best_point ) |
| continue; |
| |
| left2right = FT_BOOL( points[prev].x < points[best_point].x ); |
| |
| first = best_segment_last; |
| last = first; |
| hit = 0; |
| |
| do |
| { |
| FT_Bool l2r; |
| FT_Pos d; |
| |
| |
| if ( !hit ) |
| { |
| /* no hit; adjust first point */ |
| first = last; |
| |
| /* also adjust first and last on point */ |
| if ( FT_CURVE_TAG( outline.tags[first] ) == |
| FT_CURVE_TAG_ON ) |
| { |
| p_first = first; |
| p_last = first; |
| } |
| else |
| { |
| p_first = -1; |
| p_last = -1; |
| } |
| |
| hit = 1; |
| } |
| |
| if ( last < best_contour_last ) |
| last++; |
| else |
| last = best_contour_first; |
| |
| if ( FT_ABS( best_y - points[first].y ) > height_threshold ) |
| { |
| /* vertical distance too large */ |
| hit = 0; |
| continue; |
| } |
| |
| /* same test as above */ |
| dist = FT_ABS( points[last].y - points[first].y ); |
| if ( dist > 5 ) |
| if ( FT_ABS( points[last].x - points[first].x ) <= |
| 20 * dist ) |
| { |
| hit = 0; |
| continue; |
| } |
| |
| if ( FT_CURVE_TAG( outline.tags[last] ) == FT_CURVE_TAG_ON ) |
| { |
| p_last = last; |
| if ( p_first < 0 ) |
| p_first = last; |
| } |
| |
| l2r = FT_BOOL( points[first].x < points[last].x ); |
| d = FT_ABS( points[last].x - points[first].x ); |
| |
| if ( l2r == left2right && |
| d >= length_threshold ) |
| { |
| /* all constraints are met; update segment after */ |
| /* finding its end */ |
| do |
| { |
| if ( last < best_contour_last ) |
| last++; |
| else |
| last = best_contour_first; |
| |
| d = FT_ABS( points[last].y - points[first].y ); |
| if ( d > 5 ) |
| if ( FT_ABS( points[next].x - points[first].x ) <= |
| 20 * dist ) |
| { |
| if ( last > best_contour_first ) |
| last--; |
| else |
| last = best_contour_last; |
| break; |
| } |
| |
| p_last = last; |
| |
| if ( FT_CURVE_TAG( outline.tags[last] ) == |
| FT_CURVE_TAG_ON ) |
| { |
| p_last = last; |
| if ( p_first < 0 ) |
| p_first = last; |
| } |
| |
| } while ( last != best_segment_first ); |
| |
| best_y = points[first].y; |
| |
| best_segment_first = first; |
| best_segment_last = last; |
| |
| best_on_point_first = p_first; |
| best_on_point_last = p_last; |
| |
| break; |
| } |
| |
| } while ( last != best_segment_first ); |
| } |
| } |
| |
| /* for computing blue zones, we add the y offset as returned */ |
| /* by the currently used OpenType feature -- for example, */ |
| /* superscript glyphs might be identical to subscript glyphs */ |
| /* with a vertical shift */ |
| best_y += y_offset; |
| |
| #ifdef FT_DEBUG_LEVEL_TRACE |
| if ( num_idx == 1 ) |
| FT_TRACE5(( " U+%04lX: best_y = %5ld", ch, best_y )); |
| else |
| FT_TRACE5(( " component %d of cluster starting with U+%04lX:" |
| " best_y = %5ld", i, ch, best_y )); |
| #endif |
| |
| /* now set the `round' flag depending on the segment's kind: */ |
| /* */ |
| /* - if the horizontal distance between the first and last */ |
| /* `on' point is larger than a heuristic threshold */ |
| /* we have a flat segment */ |
| /* - if either the first or the last point of the segment is */ |
| /* an `off' point, the segment is round, otherwise it is */ |
| /* flat */ |
| if ( best_on_point_first >= 0 && |
| best_on_point_last >= 0 && |
| ( FT_ABS( points[best_on_point_last].x - |
| points[best_on_point_first].x ) ) > |
| flat_threshold ) |
| round = 0; |
| else |
| round = FT_BOOL( |
| FT_CURVE_TAG( outline.tags[best_segment_first] ) != |
| FT_CURVE_TAG_ON || |
| FT_CURVE_TAG( outline.tags[best_segment_last] ) != |
| FT_CURVE_TAG_ON ); |
| |
| if ( round && AF_LATIN_IS_NEUTRAL_BLUE( bs ) ) |
| { |
| /* only use flat segments for a neutral blue zone */ |
| FT_TRACE5(( " (round, skipped)\n" )); |
| continue; |
| } |
| |
| FT_TRACE5(( " (%s)\n", round ? "round" : "flat" )); |
| } |
| |
| if ( AF_LATIN_IS_TOP_BLUE( bs ) ) |
| { |
| if ( best_y > best_y_extremum ) |
| { |
| best_y_extremum = best_y; |
| best_round = round; |
| } |
| } |
| else |
| { |
| if ( best_y < best_y_extremum ) |
| { |
| best_y_extremum = best_y; |
| best_round = round; |
| } |
| } |
| |
| } /* end for loop */ |
| |
| if ( !( best_y_extremum == FT_INT_MIN || |
| best_y_extremum == FT_INT_MAX ) ) |
| { |
| if ( best_round ) |
| rounds[num_rounds++] = best_y_extremum; |
| else |
| flats[num_flats++] = best_y_extremum; |
| } |
| |
| } /* end while loop */ |
| |
| if ( num_flats == 0 && num_rounds == 0 ) |
| { |
| /* |
| * we couldn't find a single glyph to compute this blue zone, |
| * we will simply ignore it then |
| */ |
| FT_TRACE5(( " empty\n" )); |
| continue; |
| } |
| |
| /* we have computed the contents of the `rounds' and `flats' tables, */ |
| /* now determine the reference and overshoot position of the blue -- */ |
| /* we simply take the median value after a simple sort */ |
| af_sort_pos( num_rounds, rounds ); |
| af_sort_pos( num_flats, flats ); |
| |
| blue = &axis->blues[axis->blue_count]; |
| blue_ref = &blue->ref.org; |
| blue_shoot = &blue->shoot.org; |
| |
| axis->blue_count++; |
| |
| if ( num_flats == 0 ) |
| { |
| *blue_ref = |
| *blue_shoot = rounds[num_rounds / 2]; |
| } |
| else if ( num_rounds == 0 ) |
| { |
| *blue_ref = |
| *blue_shoot = flats[num_flats / 2]; |
| } |
| else |
| { |
| *blue_ref = flats [num_flats / 2]; |
| *blue_shoot = rounds[num_rounds / 2]; |
| } |
| |
| /* there are sometimes problems: if the overshoot position of top */ |
| /* zones is under its reference position, or the opposite for bottom */ |
| /* zones. We must thus check everything there and correct the errors */ |
| if ( *blue_shoot != *blue_ref ) |
| { |
| FT_Pos ref = *blue_ref; |
| FT_Pos shoot = *blue_shoot; |
| FT_Bool over_ref = FT_BOOL( shoot > ref ); |
| |
| |
| if ( ( AF_LATIN_IS_TOP_BLUE( bs ) || |
| AF_LATIN_IS_SUB_TOP_BLUE( bs) ) ^ over_ref ) |
| { |
| *blue_ref = |
| *blue_shoot = ( shoot + ref ) / 2; |
| |
| FT_TRACE5(( " [overshoot smaller than reference," |
| " taking mean value]\n" )); |
| } |
| } |
| |
| blue->ascender = ascender; |
| blue->descender = descender; |
| |
| blue->flags = 0; |
| if ( AF_LATIN_IS_TOP_BLUE( bs ) ) |
| blue->flags |= AF_LATIN_BLUE_TOP; |
| if ( AF_LATIN_IS_SUB_TOP_BLUE( bs ) ) |
| blue->flags |= AF_LATIN_BLUE_SUB_TOP; |
| if ( AF_LATIN_IS_NEUTRAL_BLUE( bs ) ) |
| blue->flags |= AF_LATIN_BLUE_NEUTRAL; |
| |
| /* |
| * The following flag is used later to adjust the y and x scales |
| * in order to optimize the pixel grid alignment of the top of small |
| * letters. |
| */ |
| if ( AF_LATIN_IS_X_HEIGHT_BLUE( bs ) ) |
| blue->flags |= AF_LATIN_BLUE_ADJUSTMENT; |
| |
| FT_TRACE5(( " -> reference = %ld\n", *blue_ref )); |
| FT_TRACE5(( " overshoot = %ld\n", *blue_shoot )); |
| |
| } /* end for loop */ |
| |
| af_shaper_buf_destroy( face, shaper_buf ); |
| |
| if ( axis->blue_count ) |
| { |
| /* we finally check whether blue zones are ordered; */ |
| /* `ref' and `shoot' values of two blue zones must not overlap */ |
| |
| FT_UInt i; |
| AF_LatinBlue blue_sorted[AF_BLUE_STRINGSET_MAX_LEN + 2]; |
| |
| |
| for ( i = 0; i < axis->blue_count; i++ ) |
| blue_sorted[i] = &axis->blues[i]; |
| |
| /* sort bottoms of blue zones... */ |
| af_latin_sort_blue( axis->blue_count, blue_sorted ); |
| |
| /* ...and adjust top values if necessary */ |
| for ( i = 0; i < axis->blue_count - 1; i++ ) |
| { |
| FT_Pos* a; |
| FT_Pos* b; |
| |
| #ifdef FT_DEBUG_LEVEL_TRACE |
| FT_Bool a_is_top = 0; |
| #endif |
| |
| |
| if ( blue_sorted[i]->flags & ( AF_LATIN_BLUE_TOP | |
| AF_LATIN_BLUE_SUB_TOP ) ) |
| { |
| a = &blue_sorted[i]->shoot.org; |
| #ifdef FT_DEBUG_LEVEL_TRACE |
| a_is_top = 1; |
| #endif |
| } |
| else |
| a = &blue_sorted[i]->ref.org; |
| |
| if ( blue_sorted[i + 1]->flags & ( AF_LATIN_BLUE_TOP | |
| AF_LATIN_BLUE_SUB_TOP ) ) |
| b = &blue_sorted[i + 1]->shoot.org; |
| else |
| b = &blue_sorted[i + 1]->ref.org; |
| |
| if ( *a > *b ) |
| { |
| *a = *b; |
| FT_TRACE5(( "blue zone overlap:" |
| " adjusting %s %ld to %ld\n", |
| a_is_top ? "overshoot" : "reference", |
| blue_sorted[i] - axis->blues, |
| *a )); |
| } |
| } |
| |
| FT_TRACE5(( "\n" )); |
| |
| return 0; |
| } |
| else |
| { |
| /* disable hinting for the current style if there are no blue zones */ |
| |
| AF_FaceGlobals globals = metrics->root.globals; |
| FT_UShort* gstyles = globals->glyph_styles; |
| |
| FT_Long i; |
| |
| |
| FT_TRACE5(( "no blue zones found:" |
| " hinting disabled for this style\n" )); |
| |
| for ( i = 0; i < globals->glyph_count; i++ ) |
| { |
| if ( ( gstyles[i] & AF_STYLE_MASK ) == sc->style ) |
| gstyles[i] = AF_STYLE_NONE_DFLT; |
| } |
| |
| FT_TRACE5(( "\n" )); |
| |
| return 1; |
| } |
| } |
| |
| |
| /* Check whether all ASCII digits have the same advance width. */ |
| |
| FT_LOCAL_DEF( void ) |
| af_latin_metrics_check_digits( AF_LatinMetrics metrics, |
| FT_Face face ) |
| { |
| FT_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_latin_metrics_init( AF_LatinMetrics metrics, |
| FT_Face face ) |
| { |
| FT_Error error = FT_Err_Ok; |
| |
| FT_CharMap oldmap = face->charmap; |
| |
| |
| metrics->units_per_em = face->units_per_EM; |
| |
| if ( !FT_Select_Charmap( face, FT_ENCODING_UNICODE ) ) |
| { |
| af_latin_metrics_init_widths( metrics, face ); |
| if ( af_latin_metrics_init_blues( metrics, face ) ) |
| { |
| /* use internal error code to indicate missing blue zones */ |
| error = -1; |
| goto Exit; |
| } |
| af_latin_metrics_check_digits( metrics, face ); |
| } |
| |
| Exit: |
| FT_Set_Charmap( face, oldmap ); |
| return error; |
| } |
| |
| |
| /* Adjust scaling value, then scale and shift widths */ |
| /* and blue zones (if applicable) for given dimension. */ |
| |
| static void |
| af_latin_metrics_scale_dim( AF_LatinMetrics metrics, |
| AF_Scaler scaler, |
| AF_Dimension dim ) |
| { |
| FT_Fixed scale; |
| FT_Pos delta; |
| AF_LatinAxis axis; |
| FT_UInt nn; |
| |
| |
| if ( dim == AF_DIMENSION_HORZ ) |
| { |
| scale = scaler->x_scale; |
| delta = scaler->x_delta; |
| } |
| else |
| { |
| scale = scaler->y_scale; |
| delta = scaler->y_delta; |
| } |
| |
| axis = &metrics->axis[dim]; |
| |
| if ( axis->org_scale == scale && axis->org_delta == delta ) |
| return; |
| |
| axis->org_scale = scale; |
| axis->org_delta = delta; |
| |
| /* |
| * correct X and Y scale to optimize the alignment of the top of small |
| * letters to the pixel grid |
| */ |
| { |
| AF_LatinAxis Axis = &metrics->axis[AF_DIMENSION_VERT]; |
| AF_LatinBlue blue = NULL; |
| |
| |
| for ( nn = 0; nn < Axis->blue_count; nn++ ) |
| { |
| if ( Axis->blues[nn].flags & AF_LATIN_BLUE_ADJUSTMENT ) |
| { |
| blue = &Axis->blues[nn]; |
| break; |
| } |
| } |
| |
| if ( blue ) |
| { |
| FT_Pos scaled; |
| FT_Pos threshold; |
| FT_Pos fitted; |
| FT_UInt limit; |
| FT_UInt ppem; |
| |
| |
| scaled = FT_MulFix( blue->shoot.org, scale ); |
| ppem = metrics->root.scaler.face->size->metrics.x_ppem; |
| limit = metrics->root.globals->increase_x_height; |
| threshold = 40; |
| |
| /* if the `increase-x-height' property is active, */ |
| /* we round up much more often */ |
| if ( limit && |
| ppem <= limit && |
| ppem >= AF_PROP_INCREASE_X_HEIGHT_MIN ) |
| threshold = 52; |
| |
| fitted = ( scaled + threshold ) & ~63; |
| |
| if ( scaled != fitted ) |
| { |
| #if 0 |
| if ( dim == AF_DIMENSION_HORZ ) |
| { |
| if ( fitted < scaled ) |
| scale -= scale / 50; /* scale *= 0.98 */ |
| } |
| else |
| #endif |
| if ( dim == AF_DIMENSION_VERT ) |
| { |
| FT_Pos max_height; |
| FT_Pos dist; |
| FT_Fixed new_scale; |
| |
| |
| new_scale = FT_MulDiv( scale, fitted, scaled ); |
| |
| /* the scaling should not change the result by more than two pixels */ |
| max_height = metrics->units_per_em; |
| |
| for ( nn = 0; nn < Axis->blue_count; nn++ ) |
| { |
| max_height = FT_MAX( max_height, Axis->blues[nn].ascender ); |
| max_height = FT_MAX( max_height, -Axis->blues[nn].descender ); |
| } |
| |
| dist = FT_ABS( FT_MulFix( max_height, new_scale - scale ) ); |
| dist &= ~127; |
| |
| if ( dist == 0 ) |
| { |
| FT_TRACE5(( "af_latin_metrics_scale_dim:" |
| " x height alignment (style `%s'):\n", |
| af_style_names[metrics->root.style_class->style] )); |
| FT_TRACE5(( " " |
| " vertical scaling changed" |
| " from %.5f to %.5f (by %ld%%)\n", |
| scale / 65536.0, |
| new_scale / 65536.0, |
| ( fitted - scaled ) * 100 / scaled )); |
| FT_TRACE5(( "\n" )); |
| |
| scale = new_scale; |
| } |
| #ifdef FT_DEBUG_LEVEL_TRACE |
| else |
| { |
| FT_TRACE5(( "af_latin_metrics_scale_dim:" |
| " x height alignment (style `%s'):\n", |
| af_style_names[metrics->root.style_class->style] )); |
| FT_TRACE5(( " " |
| " excessive vertical scaling abandoned\n" )); |
| FT_TRACE5(( "\n" )); |
| } |
| #endif |
| } |
| } |
| } |
| } |
| |
| axis->scale = scale; |
| axis->delta = delta; |
| |
| if ( dim == AF_DIMENSION_HORZ ) |
| { |
| metrics->root.scaler.x_scale = scale; |
| metrics->root.scaler.x_delta = delta; |
| } |
| else |
| { |
| metrics->root.scaler.y_scale = scale; |
| metrics->root.scaler.y_delta = delta; |
| } |
| |
| FT_TRACE5(( "%s widths (style `%s')\n", |
| dim == AF_DIMENSION_HORZ ? "horizontal" : "vertical", |
| af_style_names[metrics->root.style_class->style] )); |
| |
| /* scale the widths */ |
| for ( nn = 0; nn < axis->width_count; nn++ ) |
| { |
| AF_Width width = axis->widths + nn; |
| |
| |
| width->cur = FT_MulFix( width->org, scale ); |
| width->fit = width->cur; |
| |
| FT_TRACE5(( " %ld scaled to %.2f\n", |
| width->org, |
| width->cur / 64.0 )); |
| } |
| |
| FT_TRACE5(( "\n" )); |
| |
| /* an extra-light axis corresponds to a standard width that is */ |
| /* smaller than 5/8 pixels */ |
| axis->extra_light = |
| FT_BOOL( FT_MulFix( axis->standard_width, scale ) < 32 + 8 ); |
| |
| #ifdef FT_DEBUG_LEVEL_TRACE |
| if ( axis->extra_light ) |
| { |
| FT_TRACE5(( "`%s' style is extra light (at current resolution)\n", |
| af_style_names[metrics->root.style_class->style] )); |
| FT_TRACE5(( "\n" )); |
| } |
| #endif |
| |
| if ( dim == AF_DIMENSION_VERT ) |
| { |
| #ifdef FT_DEBUG_LEVEL_TRACE |
| if ( axis->blue_count ) |
| FT_TRACE5(( "blue zones (style `%s')\n", |
| af_style_names[metrics->root.style_class->style] )); |
| #endif |
| |
| /* scale the blue zones */ |
| for ( nn = 0; nn < axis->blue_count; nn++ ) |
| { |
| AF_LatinBlue blue = &axis->blues[nn]; |
| FT_Pos dist; |
| |
| |
| blue->ref.cur = FT_MulFix( blue->ref.org, scale ) + delta; |
| blue->ref.fit = blue->ref.cur; |
| blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta; |
| blue->shoot.fit = blue->shoot.cur; |
| blue->flags &= ~AF_LATIN_BLUE_ACTIVE; |
| |
| /* a blue zone is only active if it is less than 3/4 pixels tall */ |
| dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale ); |
| if ( dist <= 48 && dist >= -48 ) |
| { |
| #if 0 |
| FT_Pos delta1; |
| #endif |
| FT_Pos delta2; |
| |
| |
| /* use discrete values for blue zone widths */ |
| |
| #if 0 |
| |
| /* generic, original code */ |
| delta1 = blue->shoot.org - blue->ref.org; |
| delta2 = delta1; |
| if ( delta1 < 0 ) |
| delta2 = -delta2; |
| |
| delta2 = FT_MulFix( delta2, scale ); |
| |
| if ( delta2 < 32 ) |
| delta2 = 0; |
| else if ( delta2 < 64 ) |
| delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 ); |
| else |
| delta2 = FT_PIX_ROUND( delta2 ); |
| |
| if ( delta1 < 0 ) |
| delta2 = -delta2; |
| |
| blue->ref.fit = FT_PIX_ROUND( blue->ref.cur ); |
| blue->shoot.fit = blue->ref.fit + delta2; |
| |
| #else |
| |
| /* simplified version due to abs(dist) <= 48 */ |
| delta2 = dist; |
| if ( dist < 0 ) |
| delta2 = -delta2; |
| |
| if ( delta2 < 32 ) |
| delta2 = 0; |
| else if ( delta2 < 48 ) |
| delta2 = 32; |
| else |
| delta2 = 64; |
| |
| if ( dist < 0 ) |
| delta2 = -delta2; |
| |
| blue->ref.fit = FT_PIX_ROUND( blue->ref.cur ); |
| blue->shoot.fit = blue->ref.fit - delta2; |
| |
| #endif |
| |
| blue->flags |= AF_LATIN_BLUE_ACTIVE; |
| } |
| } |
| |
| /* use sub-top blue zone only if it doesn't overlap with */ |
| /* another (non-sup-top) blue zone; otherwise, the */ |
| /* effect would be similar to a neutral blue zone, which */ |
| /* is not desired here */ |
| for ( nn = 0; nn < axis->blue_count; nn++ ) |
| { |
| AF_LatinBlue blue = &axis->blues[nn]; |
| FT_UInt i; |
| |
| |
| if ( !( blue->flags & AF_LATIN_BLUE_SUB_TOP ) ) |
| continue; |
| if ( !( blue->flags & AF_LATIN_BLUE_ACTIVE ) ) |
| continue; |
| |
| for ( i = 0; i < axis->blue_count; i++ ) |
| { |
| AF_LatinBlue b = &axis->blues[i]; |
| |
| |
| if ( b->flags & AF_LATIN_BLUE_SUB_TOP ) |
| continue; |
| if ( !( b->flags & AF_LATIN_BLUE_ACTIVE ) ) |
| continue; |
| |
| if ( b->ref.fit <= blue->shoot.fit && |
| b->shoot.fit >= blue->ref.fit ) |
| { |
| blue->flags &= ~AF_LATIN_BLUE_ACTIVE; |
| break; |
| } |
| } |
| } |
| |
| #ifdef FT_DEBUG_LEVEL_TRACE |
| for ( nn = 0; nn < axis->blue_count; nn++ ) |
| { |
| AF_LatinBlue blue = &axis->blues[nn]; |
| |
| |
| FT_TRACE5(( " reference %d: %ld scaled to %.2f%s\n", |
| nn, |
| blue->ref.org, |
| blue->ref.fit / 64.0, |
| ( blue->flags & AF_LATIN_BLUE_ACTIVE ) ? "" |
| : " (inactive)" )); |
| FT_TRACE5(( " overshoot %d: %ld scaled to %.2f%s\n", |
| nn, |
| blue->shoot.org, |
| blue->shoot.fit / 64.0, |
| ( blue->flags & AF_LATIN_BLUE_ACTIVE ) ? "" |
| : " (inactive)" )); |
| } |
| #endif |
| } |
| } |
| |
| |
| /* Scale global values in both directions. */ |
| |
| FT_LOCAL_DEF( void ) |
| af_latin_metrics_scale( AF_LatinMetrics metrics, |
| AF_Scaler scaler ) |
| { |
| metrics->root.scaler.render_mode = scaler->render_mode; |
| metrics->root.scaler.face = scaler->face; |
| metrics->root.scaler.flags = scaler->flags; |
| |
| af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ ); |
| af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT ); |
| } |
| |
| |
| /* Extract standard_width from writing system/script specific */ |
| /* metrics class. */ |
| |
| FT_LOCAL_DEF( void ) |
| af_latin_get_standard_widths( AF_LatinMetrics metrics, |
| FT_Pos* stdHW, |
| FT_Pos* stdVW ) |
| { |
| if ( stdHW ) |
| *stdHW = metrics->axis[AF_DIMENSION_VERT].standard_width; |
| |
| if ( stdVW ) |
| *stdVW = metrics->axis[AF_DIMENSION_HORZ].standard_width; |
| } |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /***** *****/ |
| /***** L A T I N G L Y P H A N A L Y S I S *****/ |
| /***** *****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| /* Walk over all contours and compute its segments. */ |
| |
| FT_LOCAL_DEF( FT_Error ) |
| af_latin_hints_compute_segments( AF_GlyphHints hints, |
| AF_Dimension dim ) |
| { |
| AF_LatinMetrics metrics = (AF_LatinMetrics)hints->metrics; |
| AF_AxisHints axis = &hints->axis[dim]; |
| FT_Memory memory = hints->memory; |
| FT_Error error = FT_Err_Ok; |
| AF_Segment segment = NULL; |
| AF_SegmentRec seg0; |
| AF_Point* contour = hints->contours; |
| AF_Point* contour_limit = contour + hints->num_contours; |
| AF_Direction major_dir, segment_dir; |
| |
| FT_Pos flat_threshold = FLAT_THRESHOLD( metrics->units_per_em ); |
| |
| |
| FT_ZERO( &seg0 ); |
| seg0.score = 32000; |
| seg0.flags = AF_EDGE_NORMAL; |
| |
| major_dir = (AF_Direction)FT_ABS( axis->major_dir ); |
| segment_dir = major_dir; |
| |
| axis->num_segments = 0; |
| |
| /* set up (u,v) in each point */ |
| if ( dim == AF_DIMENSION_HORZ ) |
| { |
| AF_Point point = hints->points; |
| AF_Point limit = point + hints->num_points; |
| |
| |
| for ( ; point < limit; point++ ) |
| { |
| point->u = point->fx; |
| point->v = point->fy; |
| } |
| } |
| else |
| { |
| AF_Point point = hints->points; |
| AF_Point limit = point + hints->num_points; |
| |
| |
| for ( ; point < limit; point++ ) |
| { |
| point->u = point->fy; |
| point->v = point->fx; |
| } |
| } |
| |
| /* do each contour separately */ |
| for ( ; contour < contour_limit; contour++ ) |
| { |
| AF_Point point = contour[0]; |
| AF_Point last = point->prev; |
| int on_edge = 0; |
| |
| /* we call values measured along a segment (point->v) */ |
| /* `coordinates', and values orthogonal to it (point->u) */ |
| /* `positions' */ |
| FT_Pos min_pos = 32000; |
| FT_Pos max_pos = -32000; |
| FT_Pos min_coord = 32000; |
| FT_Pos max_coord = -32000; |
| FT_UShort min_flags = AF_FLAG_NONE; |
| FT_UShort max_flags = AF_FLAG_NONE; |
| FT_Pos min_on_coord = 32000; |
| FT_Pos max_on_coord = -32000; |
| |
| FT_Bool passed; |
| |
| AF_Segment prev_segment = NULL; |
| |
| FT_Pos prev_min_pos = min_pos; |
| FT_Pos prev_max_pos = max_pos; |
| FT_Pos prev_min_coord = min_coord; |
| FT_Pos prev_max_coord = max_coord; |
| FT_UShort prev_min_flags = min_flags; |
| FT_UShort prev_max_flags = max_flags; |
| FT_Pos prev_min_on_coord = min_on_coord; |
| FT_Pos prev_max_on_coord = max_on_coord; |
| |
| |
| if ( FT_ABS( last->out_dir ) == major_dir && |
| FT_ABS( point->out_dir ) == major_dir ) |
| { |
| /* we are already on an edge, try to locate its start */ |
| last = point; |
| |
| for (;;) |
| { |
| point = point->prev; |
| if ( FT_ABS( point->out_dir ) != major_dir ) |
| { |
| point = point->next; |
| break; |
| } |
| if ( point == last ) |
| break; |
| } |
| } |
| |
| last = point; |
| passed = 0; |
| |
| for (;;) |
| { |
| FT_Pos u, v; |
| |
| |
| if ( on_edge ) |
| { |
| /* get minimum and maximum position */ |
| u = point->u; |
| if ( u < min_pos ) |
| min_pos = u; |
| if ( u > max_pos ) |
| max_pos = u; |
| |
| /* get minimum and maximum coordinate together with flags */ |
| v = point->v; |
| if ( v < min_coord ) |
| { |
| min_coord = v; |
| min_flags = point->flags; |
| } |
| if ( v > max_coord ) |
| { |
| max_coord = v; |
| max_flags = point->flags; |
| } |
| |
| /* get minimum and maximum coordinate of `on' points */ |
| if ( !( point->flags & AF_FLAG_CONTROL ) ) |
| { |
| v = point->v; |
| if ( v < min_on_coord ) |
| min_on_coord = v; |
| if ( v > max_on_coord ) |
| max_on_coord = v; |
| } |
| |
| if ( point->out_dir != segment_dir || point == last ) |
| { |
| /* check whether the new segment's start point is identical to */ |
| /* the previous segment's end point; for example, this might */ |
| /* happen for spikes */ |
| |
| if ( !prev_segment || segment->first != prev_segment->last ) |
| { |
| /* points are different: we are just leaving an edge, thus */ |
| /* record a new segment */ |
| |
| segment->last = point; |
| segment->pos = (FT_Short)( ( min_pos + max_pos ) >> 1 ); |
| segment->delta = (FT_Short)( ( max_pos - min_pos ) >> 1 ); |
| |
| /* a segment is round if either its first or last point */ |
| /* is a control point, and the length of the on points */ |
| /* inbetween doesn't exceed a heuristic limit */ |
| if ( ( min_flags | max_flags ) & AF_FLAG_CONTROL && |
| ( max_on_coord - min_on_coord ) < flat_threshold ) |
| segment->flags |= AF_EDGE_ROUND; |
| |
| segment->min_coord = (FT_Short)min_coord; |
| segment->max_coord = (FT_Short)max_coord; |
| segment->height = segment->max_coord - segment->min_coord; |
| |
| prev_segment = segment; |
| prev_min_pos = min_pos; |
| prev_max_pos = max_pos; |
| prev_min_coord = min_coord; |
| prev_max_coord = max_coord; |
| prev_min_flags = min_flags; |
| prev_max_flags = max_flags; |
| prev_min_on_coord = min_on_coord; |
| prev_max_on_coord = max_on_coord; |
| } |
| else |
| { |
| /* points are the same: we don't create a new segment but */ |
| /* merge the current segment with the previous one */ |
| |
| if ( prev_segment->last->in_dir == point->in_dir ) |
| { |
| /* we have identical directions (this can happen for */ |
| /* degenerate outlines that move zig-zag along the main */ |
| /* axis without changing the coordinate value of the other */ |
| /* axis, and where the segments have just been merged): */ |
| /* unify segments */ |
| |
| /* update constraints */ |
| |
| if ( prev_min_pos < min_pos ) |
| min_pos = prev_min_pos; |
| if ( prev_max_pos > max_pos ) |
| max_pos = prev_max_pos; |
| |
| if ( prev_min_coord < min_coord ) |
| { |
| min_coord = prev_min_coord; |
| min_flags = prev_min_flags; |
| } |
| if ( prev_max_coord > max_coord ) |
| { |
| max_coord = prev_max_coord; |
| max_flags = prev_max_flags; |
| } |
| |
| if ( prev_min_on_coord < min_on_coord ) |
| min_on_coord = prev_min_on_coord; |
| if ( prev_max_on_coord > max_on_coord ) |
| max_on_coord = prev_max_on_coord; |
| |
| prev_segment->last = point; |
| prev_segment->pos = (FT_Short)( ( min_pos + |
| max_pos ) >> 1 ); |
| prev_segment->delta = (FT_Short)( ( max_pos - |
| min_pos ) >> 1 ); |
| |
| if ( ( min_flags | max_flags ) & AF_FLAG_CONTROL && |
| ( max_on_coord - min_on_coord ) < flat_threshold ) |
| prev_segment->flags |= AF_EDGE_ROUND; |
| else |
| prev_segment->flags &= ~AF_EDGE_ROUND; |
| |
| prev_segment->min_coord = (FT_Short)min_coord; |
| prev_segment->max_coord = (FT_Short)max_coord; |
| prev_segment->height = prev_segment->max_coord - |
| prev_segment->min_coord; |
| } |
| else |
| { |
| /* we have different directions; use the properties of the */ |
| /* longer segment and discard the other one */ |
| |
| if ( FT_ABS( prev_max_coord - prev_min_coord ) > |
| FT_ABS( max_coord - min_coord ) ) |
| { |
| /* discard current segment */ |
| |
| if ( min_pos < prev_min_pos ) |
| prev_min_pos = min_pos; |
| if ( max_pos > prev_max_pos ) |
| prev_max_pos = max_pos; |
| |
| prev_segment->last = point; |
| prev_segment->pos = (FT_Short)( ( prev_min_pos + |
| prev_max_pos ) >> 1 ); |
| prev_segment->delta = (FT_Short)( ( prev_max_pos - |
| prev_min_pos ) >> 1 ); |
| } |
| else |
| { |
| /* discard previous segment */ |
| |
| if ( prev_min_pos < min_pos ) |
| min_pos = prev_min_pos; |
| if ( prev_max_pos > max_pos ) |
| max_pos = prev_max_pos; |
| |
| segment->last = point; |
| segment->pos = (FT_Short)( ( min_pos + max_pos ) >> 1 ); |
| segment->delta = (FT_Short)( ( max_pos - min_pos ) >> 1 ); |
| |
| if ( ( min_flags | max_flags ) & AF_FLAG_CONTROL && |
| ( max_on_coord - min_on_coord ) < flat_threshold ) |
| segment->flags |= AF_EDGE_ROUND; |
| |
| segment->min_coord = (FT_Short)min_coord; |
| segment->max_coord = (FT_Short)max_coord; |
| segment->height = segment->max_coord - |
| segment->min_coord; |
| |
| *prev_segment = *segment; |
| |
| prev_min_pos = min_pos; |
| prev_max_pos = max_pos; |
| prev_min_coord = min_coord; |
| prev_max_coord = max_coord; |
| prev_min_flags = min_flags; |
| prev_max_flags = max_flags; |
| prev_min_on_coord = min_on_coord; |
| prev_max_on_coord = max_on_coord; |
| } |
| } |
| |
| axis->num_segments--; |
| } |
| |
| on_edge = 0; |
| segment = NULL; |
| |
| /* fall through */ |
| } |
| } |
| |
| /* now exit if we are at the start/end point */ |
| if ( point == last ) |
| { |
| if ( passed ) |
| break; |
| passed = 1; |
| } |
| |
| /* if we are not on an edge, check whether the major direction */ |
| /* coincides with the current point's `out' direction, or */ |
| /* whether we have a single-point contour */ |
| if ( !on_edge && |
| ( FT_ABS( point->out_dir ) == major_dir || |
| point == point->prev ) ) |
| { |
| /* |
| * For efficiency, we restrict the number of segments to 1000, |
| * which is a heuristic value: it is very unlikely that a glyph |
| * with so many segments can be hinted in a sensible way. |
| * Reasons: |
| * |
| * - The glyph has really 1000 segments; this implies that it has |
| * at least 2000 outline points. Assuming 'normal' fonts that |
| * have superfluous points optimized away, viewing such a glyph |
| * only makes sense at large magnifications where hinting |
| * isn't applied anyway. |
| * |
| * - We have a broken glyph. Hinting doesn't make sense in this |
| * case either. |
| */ |
| if ( axis->num_segments > 1000 ) |
| { |
| FT_TRACE0(( "af_latin_hints_compute_segments:" |
| " more than 1000 segments in this glyph;\n" )); |
| FT_TRACE0(( " " |
| " hinting is suppressed\n" )); |
| axis->num_segments = 0; |
| return FT_Err_Ok; |
| } |
| |
| /* this is the start of a new segment! */ |
| segment_dir = (AF_Direction)point->out_dir; |
| |
| error = af_axis_hints_new_segment( axis, memory, &segment ); |
| if ( error ) |
| goto Exit; |
| |
| /* clear all segment fields */ |
| segment[0] = seg0; |
| |
| segment->dir = (FT_Char)segment_dir; |
| segment->first = point; |
| segment->last = point; |
| |
| /* `af_axis_hints_new_segment' reallocates memory, */ |
| /* thus we have to refresh the `prev_segment' pointer */ |
| if ( prev_segment ) |
| prev_segment = segment - 1; |
| |
| min_pos = max_pos = point->u; |
| min_coord = max_coord = point->v; |
| min_flags = max_flags = point->flags; |
| |
| if ( point->flags & AF_FLAG_CONTROL ) |
| { |
| min_on_coord = 32000; |
| max_on_coord = -32000; |
| } |
| else |
| min_on_coord = max_on_coord = point->v; |
| |
| on_edge = 1; |
| |
| if ( point == point->prev ) |
| { |
| /* we have a one-point segment: this is a one-point */ |
| /* contour with `in' and `out' direction set to */ |
| /* AF_DIR_NONE */ |
| segment->pos = (FT_Short)min_pos; |
| |
| if (point->flags & AF_FLAG_CONTROL) |
| segment->flags |= AF_EDGE_ROUND; |
| |
| segment->min_coord = (FT_Short)point->v; |
| segment->max_coord = (FT_Short)point->v; |
| segment->height = 0; |
| |
| on_edge = 0; |
| segment = NULL; |
| } |
| } |
| |
| point = point->next; |
| } |
| |
| } /* contours */ |
| |
| |
| /* now slightly increase the height of segments if this makes */ |
| /* sense -- this is used to better detect and ignore serifs */ |
| { |
| AF_Segment segments = axis->segments; |
| AF_Segment segments_end = FT_OFFSET( segments, axis->num_segments ); |
| |
| |
| for ( segment = segments; segment < segments_end; segment++ ) |
| { |
| AF_Point first = segment->first; |
| AF_Point last = segment->last; |
| FT_Pos first_v = first->v; |
| FT_Pos last_v = last->v; |
| |
| |
| if ( first_v < last_v ) |
| { |
| AF_Point p; |
| |
| |
| p = first->prev; |
| if ( p->v < first_v ) |
| segment->height = (FT_Short)( segment->height + |
| ( ( first_v - p->v ) >> 1 ) ); |
| |
| p = last->next; |
| if ( p->v > last_v ) |
| segment->height = (FT_Short)( segment->height + |
| ( ( p->v - last_v ) >> 1 ) ); |
| } |
| else |
| { |
| AF_Point p; |
| |
| |
| p = first->prev; |
| if ( p->v > first_v ) |
| segment->height = (FT_Short)( segment->height + |
| ( ( p->v - first_v ) >> 1 ) ); |
| |
| p = last->next; |
| if ( p->v < last_v ) |
| segment->height = (FT_Short)( segment->height + |
| ( ( last_v - p->v ) >> 1 ) ); |
| } |
| } |
| } |
| |
| Exit: |
| return error; |
| } |
| |
| |
| /* Link segments to form stems and serifs. If `width_count' and */ |
| /* `widths' are non-zero, use them to fine-tune the scoring function. */ |
| |
| FT_LOCAL_DEF( void ) |
| af_latin_hints_link_segments( AF_GlyphHints hints, |
| FT_UInt width_count, |
| AF_WidthRec* widths, |
| AF_Dimension dim ) |
| { |
| AF_AxisHints axis = &hints->axis[dim]; |
| AF_Segment segments = axis->segments; |
| AF_Segment segment_limit = FT_OFFSET( segments, axis->num_segments ); |
| FT_Pos len_threshold, len_score, dist_score, max_width; |
| AF_Segment seg1, seg2; |
| |
| |
| if ( width_count ) |
| max_width = widths[width_count - 1].org; |
| else |
| max_width = 0; |
| |
| /* a heuristic value to set up a minimum value for overlapping */ |
| len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 ); |
| if ( len_threshold == 0 ) |
| len_threshold = 1; |
| |
| /* a heuristic value to weight lengths */ |
| len_score = AF_LATIN_CONSTANT( hints->metrics, 6000 ); |
| |
| /* a heuristic value to weight distances (no call to */ |
| /* AF_LATIN_CONSTANT needed, since we work on multiples */ |
| /* of the stem width) */ |
| dist_score = 3000; |
| |
| /* now compare each segment to the others */ |
| for ( seg1 = segments; seg1 < segment_limit; seg1++ ) |
| { |
| if ( seg1->dir != axis->major_dir ) |
| continue; |
| |
| /* search for stems having opposite directions, */ |
| /* with seg1 to the `left' of seg2 */ |
| for ( seg2 = segments; seg2 < segment_limit; seg2++ ) |
| { |
| FT_Pos pos1 = seg1->pos; |
| FT_Pos pos2 = seg2->pos; |
| |
| |
| if ( seg1->dir + seg2->dir == 0 && pos2 > pos1 ) |
| { |
| /* compute distance between the two segments */ |
| FT_Pos min = seg1->min_coord; |
| FT_Pos max = seg1->max_coord; |
| FT_Pos len; |
| |
| |
| if ( min < seg2->min_coord ) |
| min = seg2->min_coord; |
| |
| if ( max > seg2->max_coord ) |
| max = seg2->max_coord; |
| |
| /* compute maximum coordinate difference of the two segments */ |
| /* (this is, how much they overlap) */ |
| len = max - min; |
| if ( len >= len_threshold ) |
| { |
| /* |
| * The score is the sum of two demerits indicating the |
| * `badness' of a fit, measured along the segments' main axis |
| * and orthogonal to it, respectively. |
| * |
| * - The less overlapping along the main axis, the worse it |
| * is, causing a larger demerit. |
| * |
| * - The nearer the orthogonal distance to a stem width, the |
| * better it is, causing a smaller demerit. For simplicity, |
| * however, we only increase the demerit for values that |
| * exceed the largest stem width. |
| */ |
| |
| FT_Pos dist = pos2 - pos1; |
| |
| FT_Pos dist_demerit, score; |
| |
| |
| if ( max_width ) |
| { |
| /* distance demerits are based on multiples of `max_width'; */ |
| /* we scale by 1024 for getting more precision */ |
| FT_Pos delta = ( dist << 10 ) / max_width - ( 1 << 10 ); |
| |
| |
| if ( delta > 10000 ) |
| dist_demerit = 32000; |
| else if ( delta > 0 ) |
| dist_demerit = delta * delta / dist_score; |
| else |
| dist_demerit = 0; |
| } |
| else |
| dist_demerit = dist; /* default if no widths available */ |
| |
| score = dist_demerit + len_score / len; |
| |
| /* and we search for the smallest score */ |
| if ( score < seg1->score ) |
| { |
| seg1->score = score; |
| seg1->link = seg2; |
| } |
| |
| if ( score < seg2->score ) |
| { |
| seg2->score = score; |
| seg2->link = seg1; |
| } |
| } |
| } |
| } |
| } |
| |
| /* now compute the `serif' segments, cf. explanations in `afhints.h' */ |
| for ( seg1 = segments; seg1 < segment_limit; seg1++ ) |
| { |
| seg2 = seg1->link; |
| |
| if ( seg2 ) |
| { |
| if ( seg2->link != seg1 ) |
| { |
| seg1->link = NULL; |
| seg1->serif = seg2->link; |
| } |
| } |
| } |
| } |
| |
| |
| /* Link segments to edges, using feature analysis for selection. */ |
| |
| FT_LOCAL_DEF( FT_Error ) |
| af_latin_hints_compute_edges( AF_GlyphHints hints, |
| AF_Dimension dim ) |
| { |
| AF_AxisHints axis = &hints->axis[dim]; |
| FT_Error error = FT_Err_Ok; |
| FT_Memory memory = hints->memory; |
| AF_LatinAxis laxis = &((AF_LatinMetrics)hints->metrics)->axis[dim]; |
| |
| AF_StyleClass style_class = hints->metrics->style_class; |
| AF_ScriptClass script_class = af_script_classes[style_class->script]; |
| |
| FT_Bool top_to_bottom_hinting = 0; |
| |
| AF_Segment segments = axis->segments; |
| AF_Segment segment_limit = FT_OFFSET( segments, axis->num_segments ); |
| AF_Segment seg; |
| |
| #if 0 |
| AF_Direction up_dir; |
| #endif |
| FT_Fixed scale; |
| FT_Pos edge_distance_threshold; |
| FT_Pos segment_length_threshold; |
| FT_Pos segment_width_threshold; |
| |
| |
| axis->num_edges = 0; |
| |
| scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale |
| : hints->y_scale; |
| |
| #if 0 |
| up_dir = ( dim == AF_DIMENSION_HORZ ) ? AF_DIR_UP |
| : AF_DIR_RIGHT; |
| #endif |
| |
| if ( dim == AF_DIMENSION_VERT ) |
| top_to_bottom_hinting = script_class->top_to_bottom_hinting; |
| |
| /* |
| * We ignore all segments that are less than 1 pixel in length |
| * to avoid many problems with serif fonts. We compute the |
| * corresponding threshold in font units. |
| */ |
| if ( dim == AF_DIMENSION_HORZ ) |
| segment_length_threshold = FT_DivFix( 64, hints->y_scale ); |
| else |
| segment_length_threshold = 0; |
| |
| /* |
| * Similarly, we ignore segments that have a width delta |
| * larger than 0.5px (i.e., a width larger than 1px). |
| */ |
| segment_width_threshold = FT_DivFix( 32, 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 gets processed in the second step to compute the |
| * edge's properties. |
| * |
| * Note that the table of edges is sorted along the segment/edge |
| * position. |
| * |
| */ |
| |
| /* assure that edge distance threshold is at most 0.25px */ |
| edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold, |
| scale ); |
| if ( edge_distance_threshold > 64 / 4 ) |
| edge_distance_threshold = 64 / 4; |
| |
| edge_distance_threshold = FT_DivFix( edge_distance_threshold, |
| scale ); |
| |
| for ( seg = segments; seg < segment_limit; seg++ ) |
| { |
| AF_Edge found = NULL; |
| FT_Int ee; |
| |
| |
| /* ignore too short segments, too wide ones, and, in this loop, */ |
| /* one-point segments without a direction */ |
| if ( seg->height < segment_length_threshold || |
| seg->delta > segment_width_threshold || |
| seg->dir == AF_DIR_NONE ) |
| continue; |
| |
| /* A special case for serif edges: If they are smaller than */ |
| /* 1.5 pixels we ignore them. */ |
| if ( seg->serif && |
| 2 * seg->height < 3 * segment_length_threshold ) |
| continue; |
| |
| /* look for an edge corresponding to the segment */ |
| for ( ee = 0; ee < axis->num_edges; ee++ ) |
| { |
| AF_Edge edge = axis->edges + ee; |
| FT_Pos dist; |
| |
| |
| dist = seg->pos - edge->fpos; |
| if ( dist < 0 ) |
| dist = -dist; |
| |
| if ( dist < edge_distance_threshold && edge->dir == seg->dir ) |
| { |
| found = edge; |
| break; |
| } |
| } |
| |
| if ( !found ) |
| { |
| AF_Edge edge; |
| |
| |
| /* insert a new edge in the list and */ |
| /* sort according to the position */ |
| error = af_axis_hints_new_edge( axis, seg->pos, |
| (AF_Direction)seg->dir, |
| top_to_bottom_hinting, |
| 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; |
| } |
| } |
| |
| /* we loop again over all segments to catch one-point segments */ |
| /* without a direction: if possible, link them to existing edges */ |
| for ( seg = segments; seg < segment_limit; seg++ ) |
| { |
| AF_Edge found = NULL; |
| FT_Int ee; |
| |
| |
| if ( seg->dir != AF_DIR_NONE ) |
| continue; |
| |
| /* look for an edge corresponding to the segment */ |
| for ( ee = 0; ee < axis->num_edges; ee++ ) |
| { |
| AF_Edge edge = axis->edges + ee; |
| FT_Pos dist; |
| |
| |
| dist = seg->pos - edge->fpos; |
| if ( dist < 0 ) |
| dist = -dist; |
| |
| if ( dist < edge_distance_threshold ) |
| { |
| found = edge; |
| break; |
| } |
| } |
| |
| /* one-point segments without a match are ignored */ |
| if ( found ) |
| { |
| 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? */ |
| #if 0 |
| FT_Pos ups = 0; /* number of upwards segments */ |
| FT_Pos downs = 0; /* number of downwards segments */ |
| #endif |
| |
| |
| seg = edge->first; |
| |
| do |
| { |
| FT_Bool is_serif; |
| |
| |
| /* check for roundness of segment */ |
| if ( seg->flags & AF_EDGE_ROUND ) |
| is_round++; |
| else |
| is_straight++; |
| |
| #if 0 |
| /* check for segment direction */ |
| if ( seg->dir == up_dir ) |
| ups += seg->max_coord - seg->min_coord; |
| else |
| downs += seg->max_coord - seg->min_coord; |
| #endif |
| |
| /* check for links -- if seg->serif is set, then seg->link must */ |
| /* be ignored */ |
| is_serif = FT_BOOL( seg->serif && |
| seg->serif->edge && |
| seg->serif->edge != edge ); |
| |
| if ( ( seg->link && seg->link->edge ) || is_serif ) |
| { |
| AF_Edge edge2; |
| AF_Segment seg2; |
| |
| |
| edge2 = edge->link; |
| seg2 = seg->link; |
| |
| if ( is_serif ) |
| { |
| seg2 = seg->serif; |
| edge2 = edge->serif; |
| } |
| |
| if ( edge2 ) |
| { |
| FT_Pos edge_delta; |
| FT_Pos seg_delta; |
| |
| |
| edge_delta = edge->fpos - edge2->fpos; |
| if ( edge_delta < 0 ) |
| edge_delta = -edge_delta; |
| |
| seg_delta = seg->pos - seg2->pos; |
| if ( seg_delta < 0 ) |
| seg_delta = -seg_delta; |
| |
| if ( seg_delta < edge_delta ) |
| edge2 = seg2->edge; |
| } |
| else |
| edge2 = seg2->edge; |
| |
| if ( is_serif ) |
| { |
| edge->serif = edge2; |
| edge2->flags |= AF_EDGE_SERIF; |
| } |
| else |
| edge->link = edge2; |
| } |
| |
| seg = seg->edge_next; |
| |
| } while ( seg != edge->first ); |
| |
| /* set the round/straight flags */ |
| edge->flags = AF_EDGE_NORMAL; |
| |
| if ( is_round > 0 && is_round >= is_straight ) |
| edge->flags |= AF_EDGE_ROUND; |
| |
| #if 0 |
| /* set the edge's main direction */ |
| edge->dir = AF_DIR_NONE; |
| |
| if ( ups > downs ) |
| edge->dir = (FT_Char)up_dir; |
| |
| else if ( ups < downs ) |
| edge->dir = (FT_Char)-up_dir; |
| |
| else if ( ups == downs ) |
| edge->dir = 0; /* both up and down! */ |
| #endif |
| |
| /* get rid of serifs if link is set */ |
| /* XXX: This gets rid of many unpleasant artefacts! */ |
| /* Example: the `c' in cour.pfa at size 13 */ |
| |
| if ( edge->serif && edge->link ) |
| edge->serif = NULL; |
| } |
| } |
| |
| Exit: |
| return error; |
| } |
| |
| |
| /* Detect segments and edges for given dimension. */ |
| |
| FT_LOCAL_DEF( FT_Error ) |
| af_latin_hints_detect_features( AF_GlyphHints hints, |
| FT_UInt width_count, |
| AF_WidthRec* widths, |
| AF_Dimension dim ) |
| { |
| FT_Error error; |
| |
| |
| error = af_latin_hints_compute_segments( hints, dim ); |
| if ( !error ) |
| { |
| af_latin_hints_link_segments( hints, width_count, widths, dim ); |
| |
| error = af_latin_hints_compute_edges( hints, dim ); |
| } |
| |
| return error; |
| } |
| |
| |
| /* Compute all edges which lie within blue zones. */ |
| |
| static void |
| af_latin_hints_compute_blue_edges( AF_GlyphHints hints, |
| AF_LatinMetrics metrics ) |
| { |
| AF_AxisHints axis = &hints->axis[AF_DIMENSION_VERT]; |
| AF_Edge edge = axis->edges; |
| AF_Edge edge_limit = FT_OFFSET( edge, axis->num_edges ); |
| AF_LatinAxis latin = &metrics->axis[AF_DIMENSION_VERT]; |
| FT_Fixed scale = latin->scale; |
| |
| |
| /* compute which blue zones are active, i.e. have their scaled */ |
| /* size < 3/4 pixels */ |
| |
| /* for each horizontal edge search the blue zone which is closest */ |
| for ( ; edge < edge_limit; edge++ ) |
| { |
| FT_UInt bb; |
| AF_Width best_blue = NULL; |
| FT_Bool best_blue_is_neutral = 0; |
| FT_Pos best_dist; /* initial threshold */ |
| |
| |
| /* compute the initial threshold as a fraction of the EM size */ |
| /* (the value 40 is heuristic) */ |
| best_dist = FT_MulFix( metrics->units_per_em / 40, scale ); |
| |
| /* assure a minimum distance of 0.5px */ |
| if ( best_dist > 64 / 2 ) |
| best_dist = 64 / 2; |
| |
| for ( bb = 0; bb < latin->blue_count; bb++ ) |
| { |
| AF_LatinBlue blue = latin->blues + bb; |
| FT_Bool is_top_blue, is_neutral_blue, is_major_dir; |
| |
| |
| /* skip inactive blue zones (i.e., those that are too large) */ |
| if ( !( blue->flags & AF_LATIN_BLUE_ACTIVE ) ) |
| continue; |
| |
| /* if it is a top zone, check for right edges (against the major */ |
| /* direction); if it is a bottom zone, check for left edges (in */ |
| /* the major direction) -- this assumes the TrueType convention */ |
| /* for the orientation of contours */ |
| is_top_blue = |
| (FT_Byte)( ( blue->flags & ( AF_LATIN_BLUE_TOP | |
| AF_LATIN_BLUE_SUB_TOP ) ) != 0 ); |
| is_neutral_blue = |
| (FT_Byte)( ( blue->flags & AF_LATIN_BLUE_NEUTRAL ) != 0); |
| is_major_dir = |
| FT_BOOL( edge->dir == axis->major_dir ); |
| |
| /* neutral blue zones are handled for both directions */ |
| if ( is_top_blue ^ is_major_dir || is_neutral_blue ) |
| { |
| FT_Pos dist; |
| |
| |
| /* first of all, compare it to the reference position */ |
| dist = edge->fpos - blue->ref.org; |
| if ( dist < 0 ) |
| dist = -dist; |
| |
| dist = FT_MulFix( dist, scale ); |
| if ( dist < best_dist ) |
| { |
| best_dist = dist; |
| best_blue = &blue->ref; |
| best_blue_is_neutral = is_neutral_blue; |
| } |
| |
| /* now compare it to the overshoot position and check whether */ |
| /* the edge is rounded, and whether the edge is over the */ |
| /* reference position of a top zone, or under the reference */ |
| /* position of a bottom zone (provided we don't have a */ |
| /* neutral blue zone) */ |
| if ( edge->flags & AF_EDGE_ROUND && |
| dist != 0 && |
| !is_neutral_blue ) |
| { |
| FT_Bool is_under_ref = FT_BOOL( edge->fpos < blue->ref.org ); |
| |
| |
| if ( is_top_blue ^ is_under_ref ) |
| { |
| dist = edge->fpos - blue->shoot.org; |
| if ( dist < 0 ) |
| dist = -dist; |
| |
| dist = FT_MulFix( dist, scale ); |
| if ( dist < best_dist ) |
| { |
| best_dist = dist; |
| best_blue = &blue->shoot; |
| best_blue_is_neutral = is_neutral_blue; |
| } |
| } |
| } |
| } |
| } |
| |
| if ( best_blue ) |
| { |
| edge->blue_edge = best_blue; |
| if ( best_blue_is_neutral ) |
| edge->flags |= AF_EDGE_NEUTRAL; |
| } |
| } |
| } |
| |
| |
| /* Initalize hinting engine. */ |
| |
| static FT_Error |
| af_latin_hints_init( AF_GlyphHints hints, |
| AF_LatinMetrics metrics ) |
| { |
| FT_Render_Mode mode; |
| FT_UInt32 scaler_flags, other_flags; |
| FT_Face face = metrics->root.scaler.face; |
| |
| |
| af_glyph_hints_rescale( hints, (AF_StyleMetrics)metrics ); |
| |
| /* |
| * correct x_scale and y_scale if needed, since they may have |
| * been modified by `af_latin_metrics_scale_dim' above |
| */ |
| hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale; |
| hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta; |
| hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale; |
| hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta; |
| |
| /* compute flags depending on render mode, etc. */ |
| mode = metrics->root.scaler.render_mode; |
| |
| scaler_flags = hints->scaler_flags; |
| other_flags = 0; |
| |
| /* |
| * We snap the width of vertical stems for the monochrome and |
| * horizontal LCD rendering targets only. |
| */ |
| if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD ) |
| other_flags |= AF_LATIN_HINTS_HORZ_SNAP; |
| |
| /* |
| * We snap the width of horizontal stems for the monochrome and |
| * vertical LCD rendering targets only. |
| */ |
| if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V ) |
| other_flags |= AF_LATIN_HINTS_VERT_SNAP; |
| |
| /* |
| * We adjust stems to full pixels unless in `light' or `lcd' mode. |
| */ |
| if ( mode != FT_RENDER_MODE_LIGHT && mode != FT_RENDER_MODE_LCD ) |
| other_flags |= AF_LATIN_HINTS_STEM_ADJUST; |
| |
| if ( mode == FT_RENDER_MODE_MONO ) |
| other_flags |= AF_LATIN_HINTS_MONO; |
| |
| /* |
| * In `light' or `lcd' mode we disable horizontal hinting completely. |
| * We also do it if the face is italic. |
| * |
| * However, if warping is enabled (which only works in `light' hinting |
| * mode), advance widths get adjusted, too. |
| */ |
| if ( mode == FT_RENDER_MODE_LIGHT || mode == FT_RENDER_MODE_LCD || |
| ( face->style_flags & FT_STYLE_FLAG_ITALIC ) != 0 ) |
| scaler_flags |= AF_SCALER_FLAG_NO_HORIZONTAL; |
| |
| hints->scaler_flags = scaler_flags; |
| hints->other_flags = other_flags; |
| |
| return FT_Err_Ok; |
| } |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /***** *****/ |
| /***** L A T I N G L Y P H G R I D - F I T T I N G *****/ |
| /***** *****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| /* Snap a given width in scaled coordinates to one of the */ |
| /* current standard widths. */ |
| |
| static FT_Pos |
| af_latin_snap_width( AF_Width widths, |
| FT_UInt count, |
| FT_Pos width ) |
| { |
| FT_UInt n; |
| FT_Pos best = 64 + 32 + 2; |
| FT_Pos reference = width; |
| FT_Pos scaled; |
| |
| |
| for ( n = 0; n < count; n++ ) |
| { |
| FT_Pos w; |
| FT_Pos dist; |
| |
| |
| w = widths[n].cur; |
| dist = width - w; |
| if ( dist < 0 ) |
| dist = -dist; |
| if ( dist < best ) |
| { |
| best = dist; |
| reference = w; |
| } |
| } |
| |
| scaled = FT_PIX_ROUND( reference ); |
| |
| if ( width >= reference ) |
| { |
| if ( width < scaled + 48 ) |
| width = reference; |
| } |
| else |
| { |
| if ( width > scaled - 48 ) |
| width = reference; |
| } |
| |
| return width; |
| } |
| |
| |
| /* Compute the snapped width of a given stem, ignoring very thin ones. */ |
| /* There is a lot of voodoo in this function; changing the hard-coded */ |
| /* parameters influence the whole hinting process. */ |
| |
| static FT_Pos |
| af_latin_compute_stem_width( AF_GlyphHints hints, |
| AF_Dimension dim, |
| FT_Pos width, |
| FT_Pos base_delta, |
| FT_UInt base_flags, |
| FT_UInt stem_flags ) |
| { |
| AF_LatinMetrics metrics = (AF_LatinMetrics)hints->metrics; |
| AF_LatinAxis axis = &metrics->axis[dim]; |
| FT_Pos dist = width; |
| FT_Int sign = 0; |
| FT_Int vertical = ( dim == AF_DIMENSION_VERT ); |
| |
| |
| if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) || |
| axis->extra_light ) |
| return width; |
| |
| if ( dist < 0 ) |
| { |
| dist = -width; |
| sign = 1; |
| } |
| |
| if ( ( vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) || |
| ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) ) |
| { |
| /* smooth hinting process: very lightly quantize the stem width */ |
| |
| /* leave the widths of serifs alone */ |
| if ( ( stem_flags & AF_EDGE_SERIF ) && |
| vertical && |
| ( dist < 3 * 64 ) ) |
| goto Done_Width; |
| |
| else if ( base_flags & AF_EDGE_ROUND ) |
| { |
| if ( dist < 80 ) |
| dist = 64; |
| } |
| else if ( dist < 56 ) |
| dist = 56; |
| |
| if ( axis->width_count > 0 ) |
| { |
| FT_Pos delta; |
| |
| |
| /* compare to standard width */ |
| delta = dist - axis->widths[0].cur; |
| |
| if ( delta < 0 ) |
| delta = -delta; |
| |
| if ( delta < 40 ) |
| { |
| dist = axis->widths[0].cur; |
| if ( dist < 48 ) |
| dist = 48; |
| |
| goto Done_Width; |
| } |
| |
| if ( dist < 3 * 64 ) |
| { |
| delta = dist & 63; |
| dist &= -64; |
| |
| if ( delta < 10 ) |
| dist += delta; |
| |
| else if ( delta < 32 ) |
| dist += 10; |
| |
| else if ( delta < 54 ) |
| dist += 54; |
| |
| else |
| dist += delta; |
| } |
| else |
| { |
| /* A stem's end position depends on two values: the start */ |
| /* position and the stem length. The former gets usually */ |
| /* rounded to the grid, while the latter gets rounded also if it */ |
| /* exceeds a certain length (see below in this function). This */ |
| /* `double rounding' can lead to a great difference to the */ |
| /* original, unhinted position; this normally doesn't matter for */ |
| /* large PPEM values, but for small sizes it can easily make */ |
| /* outlines collide. For this reason, we adjust the stem length */ |
| /* by a small amount depending on the PPEM value in case the */ |
| /* former and latter rounding both point into the same */ |
| /* direction. */ |
| |
| FT_Pos bdelta = 0; |
| |
| |
| if ( ( ( width > 0 ) && ( base_delta > 0 ) ) || |
| ( ( width < 0 ) && ( base_delta < 0 ) ) ) |
| { |
| FT_UInt ppem = metrics->root.scaler.face->size->metrics.x_ppem; |
| |
| |
| if ( ppem < 10 ) |
| bdelta = base_delta; |
| else if ( ppem < 30 ) |
| bdelta = ( base_delta * (FT_Pos)( 30 - ppem ) ) / 20; |
| |
| if ( bdelta < 0 ) |
| bdelta = -bdelta; |
| } |
| |
| dist = ( dist - bdelta + 32 ) & ~63; |
| } |
| } |
| } |
| else |
| { |
| /* strong hinting process: snap the stem width to integer pixels */ |
| |
| FT_Pos org_dist = dist; |
| |
| |
| dist = af_latin_snap_width( axis->widths, axis->width_count, dist ); |
| |
| if ( vertical ) |
| { |
| /* in the case of vertical hinting, always round */ |
| /* the stem heights to integer pixels */ |
| |
| if ( dist >= 64 ) |
| dist = ( dist + 16 ) & ~63; |
| else |
| dist = 64; |
| } |
| else |
| { |
| if ( AF_LATIN_HINTS_DO_MONO( hints ) ) |
| { |
| /* monochrome horizontal hinting: snap widths to integer pixels */ |
| /* with a different threshold */ |
| |
| if ( dist < 64 ) |
| dist = 64; |
| else |
| dist = ( dist + 32 ) & ~63; |
| } |
| else |
| { |
| /* for horizontal anti-aliased hinting, we adopt a more subtle */ |
| /* approach: we strengthen small stems, round stems whose size */ |
| /* is between 1 and 2 pixels to an integer, otherwise nothing */ |
| |
| if ( dist < 48 ) |
| dist = ( dist + 64 ) >> 1; |
| |
| else if ( dist < 128 ) |
| { |
| /* We only round to an integer width if the corresponding */ |
| /* distortion is less than 1/4 pixel. Otherwise this */ |
| /* makes everything worse since the diagonals, which are */ |
| /* not hinted, appear a lot bolder or thinner than the */ |
| /* vertical stems. */ |
| |
| FT_Pos delta; |
| |
| |
| dist = ( dist + 22 ) & ~63; |
| delta = dist - org_dist; |
| if ( delta < 0 ) |
| delta = -delta; |
| |
| if ( delta >= 16 ) |
| { |
| dist = org_dist; |
| if ( dist < 48 ) |
| dist = ( dist + 64 ) >> 1; |
| } |
| } |
| else |
| /* round otherwise to prevent color fringes in LCD mode */ |
| dist = ( dist + 32 ) & ~63; |
| } |
| } |
| } |
| |
| Done_Width: |
| if ( sign ) |
| dist = -dist; |
| |
| return dist; |
| } |
| |
| |
| /* Align one stem edge relative to the previous stem edge. */ |
| |
| static void |
| af_latin_align_linked_edge( AF_GlyphHints hints, |
| AF_Dimension dim, |
| AF_Edge base_edge, |
| AF_Edge stem_edge ) |
| { |
| FT_Pos dist, base_delta; |
| FT_Pos fitted_width; |
| |
| |
| dist = stem_edge->opos - base_edge->opos; |
| base_delta = base_edge->pos - base_edge->opos; |
| |
| fitted_width = af_latin_compute_stem_width( hints, dim, |
| dist, base_delta, |
| base_edge->flags, |
| stem_edge->flags ); |
| |
| |
| stem_edge->pos = base_edge->pos + fitted_width; |
| |
| FT_TRACE5(( " LINK: edge %ld (opos=%.2f) linked to %.2f," |
| " dist was %.2f, now %.2f\n", |
| stem_edge - hints->axis[dim].edges, stem_edge->opos / 64.0, |
| stem_edge->pos / 64.0, dist / 64.0, fitted_width / 64.0 )); |
| } |
| |
| |
| /* Shift the coordinates of the `serif' edge by the same amount */ |
| /* as the corresponding `base' edge has been moved already. */ |
| |
| static void |
| af_latin_align_serif_edge( AF_GlyphHints hints, |
| AF_Edge base, |
| AF_Edge serif ) |
| { |
| FT_UNUSED( hints ); |
| |
| serif->pos = base->pos + ( serif->opos - base->opos ); |
| } |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /**** ****/ |
| /**** E D G E H I N T I N G ****/ |
| /**** ****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| /* The main grid-fitting routine. */ |
| |
| static void |
| af_latin_hint_edges( AF_GlyphHints hints, |
| AF_Dimension dim ) |
| { |
| AF_AxisHints axis = &hints->axis[dim]; |
| AF_Edge edges = axis->edges; |
| AF_Edge edge_limit = FT_OFFSET( edges, axis->num_edges ); |
| FT_PtrDist n_edges; |
| AF_Edge edge; |
| AF_Edge anchor = NULL; |
| FT_Int has_serifs = 0; |
| |
| AF_StyleClass style_class = hints->metrics->style_class; |
| AF_ScriptClass script_class = af_script_classes[style_class->script]; |
| |
| FT_Bool top_to_bottom_hinting = 0; |
| |
| #ifdef FT_DEBUG_LEVEL_TRACE |
| FT_UInt num_actions = 0; |
| #endif |
| |
| |
| FT_TRACE5(( "latin %s edge hinting (style `%s')\n", |
| dim == AF_DIMENSION_VERT ? "horizontal" : "vertical", |
| af_style_names[hints->metrics->style_class->style] )); |
| |
| if ( dim == AF_DIMENSION_VERT ) |
| top_to_bottom_hinting = script_class->top_to_bottom_hinting; |
| |
| /* we begin by aligning all stems relative to the blue zone */ |
| /* if needed -- that's only for horizontal edges */ |
| |
| if ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_BLUES( hints ) ) |
| { |
| for ( edge = edges; edge < edge_limit; edge++ ) |
| { |
| AF_Width blue; |
| AF_Edge edge1, edge2; /* these edges form the stem to check */ |
| |
| |
| if ( edge->flags & AF_EDGE_DONE ) |
| continue; |
| |
| edge1 = NULL; |
| edge2 = edge->link; |
| |
| /* |
| * If a stem contains both a neutral and a non-neutral blue zone, |
| * skip the neutral one. Otherwise, outlines with different |
| * directions might be incorrectly aligned at the same vertical |
| * position. |
| * |
| * If we have two neutral blue zones, skip one of them. |
| * |
| */ |
| if ( edge->blue_edge && edge2 && edge2->blue_edge ) |
| { |
| FT_Byte neutral = edge->flags & AF_EDGE_NEUTRAL; |
| FT_Byte neutral2 = edge2->flags & AF_EDGE_NEUTRAL; |
| |
| |
| if ( neutral2 ) |
| { |
| edge2->blue_edge = NULL; |
| edge2->flags &= ~AF_EDGE_NEUTRAL; |
| } |
| else if ( neutral ) |
| { |
| edge->blue_edge = NULL; |
| edge->flags &= ~AF_EDGE_NEUTRAL; |
| } |
| } |
| |
| blue = edge->blue_edge; |
| if ( blue ) |
| edge1 = edge; |
| |
| /* flip edges if the other edge is aligned to a blue zone */ |
| else if ( edge2 && edge2->blue_edge ) |
| { |
| blue = edge2->blue_edge; |
| edge1 = edge2; |
| edge2 = edge; |
| } |
| |
| if ( !edge1 ) |
| continue; |
| |
| #ifdef FT_DEBUG_LEVEL_TRACE |
| if ( !anchor ) |
| FT_TRACE5(( " BLUE_ANCHOR: edge %ld (opos=%.2f) snapped to %.2f," |
| " was %.2f (anchor=edge %ld)\n", |
| edge1 - edges, edge1->opos / 64.0, blue->fit / 64.0, |
| edge1->pos / 64.0, edge - edges )); |
| else |
| FT_TRACE5(( " BLUE: edge %ld (opos=%.2f) snapped to %.2f," |
| " was %.2f\n", |
| edge1 - edges, edge1->opos / 64.0, blue->fit / 64.0, |
| edge1->pos / 64.0 )); |
| |
| num_actions++; |
| #endif |
| |
| edge1->pos = blue->fit; |
| edge1->flags |= AF_EDGE_DONE; |
| |
| if ( edge2 && !edge2->blue_edge ) |
| { |
| af_latin_align_linked_edge( hints, dim, edge1, edge2 ); |
| edge2->flags |= AF_EDGE_DONE; |
| |
| #ifdef FT_DEBUG_LEVEL_TRACE |
| num_actions++; |
| #endif |
| } |
| |
| if ( !anchor ) |
| anchor = edge; |
| } |
| } |
| |
| /* now we align all other stem edges, trying to maintain the */ |
| /* relative order of stems in the glyph */ |
| for ( edge = edges; edge < edge_limit; edge++ ) |
| { |
| AF_Edge edge2; |
| |
| |
| if ( edge->flags & AF_EDGE_DONE ) |
| continue; |
| |
| /* skip all non-stem edges */ |
| edge2 = edge->link; |
| if ( !edge2 ) |
| { |
| has_serifs++; |
| continue; |
| } |
| |
| /* now align the stem */ |
| |
| /* this should not happen, but it's better to be safe */ |
| if ( edge2->blue_edge ) |
| { |
| FT_TRACE5(( " ASSERTION FAILED for edge %ld\n", edge2 - edges )); |
| |
| af_latin_align_linked_edge( hints, dim, edge2, edge ); |
| edge->flags |= AF_EDGE_DONE; |
| |
| #ifdef FT_DEBUG_LEVEL_TRACE |
| num_actions++; |
| #endif |
| continue; |
| } |
| |
| if ( !anchor ) |
| { |
| /* if we reach this if clause, no stem has been aligned yet */ |
| |
| FT_Pos org_len, org_center, cur_len; |
| FT_Pos cur_pos1, error1, error2, u_off, d_off; |
| |
| |
| org_len = edge2->opos - edge->opos; |
| cur_len = af_latin_compute_stem_width( hints, dim, |
| org_len, 0, |
| edge->flags, |
| edge2->flags ); |
| |
| /* some voodoo to specially round edges for small stem widths; */ |
| /* the idea is to align the center of a stem, then shifting */ |
| /* the stem edges to suitable positions */ |
| if ( cur_len <= 64 ) |
| { |
| /* width <= 1px */ |
| u_off = 32; |
| d_off = 32; |
| } |
| else |
| { |
| /* 1px < width < 1.5px */ |
| u_off = 38; |
| d_off = 26; |
| } |
| |
| if ( cur_len < 96 ) |
| { |
| org_center = edge->opos + ( org_len >> 1 ); |
| cur_pos1 = FT_PIX_ROUND( org_center ); |
| |
| error1 = org_center - ( cur_pos1 - u_off ); |
| if ( error1 < 0 ) |
| error1 = -error1; |
| |
| error2 = org_center - ( cur_pos1 + d_off ); |
| if ( error2 < 0 ) |
| error2 = -error2; |
| |
| if ( error1 < error2 ) |
| cur_pos1 -= u_off; |
| else |
| cur_pos1 += d_off; |
| |
| edge->pos = cur_pos1 - cur_len / 2; |
| edge2->pos = edge->pos + cur_len; |
| } |
| else |
| edge->pos = FT_PIX_ROUND( edge->opos ); |
| |
| anchor = edge; |
| edge->flags |= AF_EDGE_DONE; |
| |
| FT_TRACE5(( " ANCHOR: edge %ld (opos=%.2f) and %ld (opos=%.2f)" |
| " snapped to %.2f and %.2f\n", |
| edge - edges, edge->opos / 64.0, |
| edge2 - edges, edge2->opos / 64.0, |
| edge->pos / 64.0, edge2->pos / 64.0 )); |
| |
| af_latin_align_linked_edge( hints, dim, edge, edge2 ); |
| |
| #ifdef FT_DEBUG_LEVEL_TRACE |
| num_actions += 2; |
| #endif |
| } |
| else |
| { |
| FT_Pos org_pos, org_len, org_center, cur_len; |
| FT_Pos cur_pos1, cur_pos2, delta1, delta2; |
| |
| |
| org_pos = anchor->pos + ( edge->opos - anchor->opos ); |
| org_len = edge2->opos - edge->opos; |
| org_center = org_pos + ( org_len >> 1 ); |
| |
| cur_len = af_latin_compute_stem_width( hints, dim, |
| org_len, 0, |
| edge->flags, |
| edge2->flags ); |
| |
| if ( edge2->flags & AF_EDGE_DONE ) |
| { |
| FT_TRACE5(( " ADJUST: edge %ld (pos=%.2f) moved to %.2f\n", |
| edge - edges, edge->pos / 64.0, |
| ( edge2->pos - cur_len ) / 64.0 )); |
| |
| edge->pos = edge2->pos - cur_len; |
| } |
| |
| else if ( cur_len < 96 ) |
| { |
|
|