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Diffstat (limited to 'src/freetype/aflatin.c')
| -rw-r--r-- | src/freetype/aflatin.c | 3572 |
1 files changed, 3572 insertions, 0 deletions
diff --git a/src/freetype/aflatin.c b/src/freetype/aflatin.c new file mode 100644 index 0000000..bcf4c23 --- /dev/null +++ b/src/freetype/aflatin.c @@ -0,0 +1,3572 @@ +/***************************************************************************/ +/* */ +/* aflatin.c */ +/* */ +/* Auto-fitter hinting routines for latin writing system (body). */ +/* */ +/* Copyright 2003-2018 by */ +/* David Turner, Robert Wilhelm, and Werner Lemberg. */ +/* */ +/* This file is part of the FreeType project, and may only be used, */ +/* modified, and distributed under the terms of the FreeType project */ +/* license, LICENSE.TXT. By continuing to use, modify, or distribute */ +/* this file you indicate that you have read the license and */ +/* understand and accept it fully. */ +/* */ +/***************************************************************************/ + + +#include "ft2build.h" +#include FT_ADVANCES_H +#include FT_INTERNAL_DEBUG_H + +#include "afglobal.h" +#include "aflatin.h" +#include "aferrors.h" + + +#ifdef AF_CONFIG_OPTION_USE_WARPER +#include "afwarp.h" +#endif + + + /*************************************************************************/ + /* */ + /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ + /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ + /* messages during execution. */ + /* */ +#undef FT_COMPONENT +#define FT_COMPONENT trace_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" + "latin 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_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]; + + void* shaper_buf; + const char* p; + +#ifdef FT_DEBUG_LEVEL_TRACE + FT_ULong ch = 0; +#endif + + p = script_class->standard_charstring; + shaper_buf = af_shaper_buf_create( face ); + + /* + * 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 ) + 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_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 = 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(( " %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 ); + } + + + 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 void + 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 ); + + void* shaper_buf; + + + /* 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" + "============================\n" + "\n" )); + + shaper_buf = af_shaper_buf_create( face ); + + 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" + " overshoot = %ld\n", + *blue_ref, *blue_shoot )); + + } /* end for loop */ + + af_shaper_buf_destroy( face, shaper_buf ); + + /* we finally check whether blue zones are ordered; */ + /* `ref' and `shoot' values of two blue zones must not overlap */ + if ( axis->blue_count ) + { + 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 %d to %ld\n", + a_is_top ? "overshoot" : "reference", + blue_sorted[i] - axis->blues, + *a )); + } + } + } + + FT_TRACE5(( "\n" )); + + return; + } + + + /* 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; + + void* shaper_buf; + + /* 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; + shaper_buf = af_shaper_buf_create( face ); + + 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_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 ); + af_latin_metrics_init_blues( metrics, face ); + af_latin_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_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" + " " + " vertical scaling changed from %.5f to %.5f (by %d%%)\n" + "\n", + af_style_names[metrics->root.style_class->style], + scale / 65536.0, + new_scale / 65536.0, + ( fitted - scaled ) * 100 / scaled )); + + scale = new_scale; + } +#ifdef FT_DEBUG_LEVEL_TRACE + else + { + FT_TRACE5(( + "af_latin_metrics_scale_dim:" + " x height alignment (style `%s'):\n" + " " + " excessive vertical scaling abandoned\n" + "\n", + af_style_names[metrics->root.style_class->style] )); + } +#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(( " %d 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" + "\n", + af_style_names[metrics->root.style_class->style] )); +#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: %d scaled to %.2f%s\n" + " overshoot %d: %d scaled to %.2f%s\n", + nn, + blue->ref.org, + blue->ref.fit / 64.0, + blue->flags & AF_LATIN_BLUE_ACTIVE ? "" + : " (inactive)", + 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 ) ) + { + /* 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 = 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 = 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. + * + * o The less overlapping along the main axis, the worse it + * is, causing a larger demerit. + * + * o 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 = 0; + 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 = 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 = 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 = 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 ) + 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 ) + 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 ) + 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 || + ( face->style_flags & FT_STYLE_FLAG_ITALIC ) != 0 ) + scaler_flags |= AF_SCALER_FLAG_NO_HORIZONTAL; + +#ifdef AF_CONFIG_OPTION_USE_WARPER + /* get (global) warper flag */ + if ( !metrics->root.globals->module->warping ) + scaler_flags |= AF_SCALER_FLAG_NO_WARPER; +#endif + + hints->scaler_flags = scaler_flags; + hints->other_flags = other_flags; + + return 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 %d (opos=%.2f) linked to %.2f," + " dist was %.2f, now %.2f\n", + stem_edge - hints->axis[dim].edges, stem_edge->opos / 64.0, + stem_edge->pos / 64.0, dist / 64.0, fitted_width / 64.0 )); + } + + + /* 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 = 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 %d (opos=%.2f) snapped to %.2f," + " was %.2f (anchor=edge %d)\n", + edge1 - edges, edge1->opos / 64.0, blue->fit / 64.0, + edge1->pos / 64.0, edge - edges )); + else + FT_TRACE5(( " BLUE: edge %d (opos=%.2f) snapped to %.2f," + " was %.2f\n", + edge1 - edges, edge1->opos / 64.0, blue->fit / 64.0, + edge1->pos / 64.0 )); + + 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 %d\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 %d (opos=%.2f) and %d (opos=%.2f)" + " snapped to %.2f and %.2f\n", + edge - edges, edge->opos / 64.0, + edge2 - edges, edge2->opos / 64.0, + edge->pos / 64.0, edge2->pos / 64.0 )); + + 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 %d (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 ) + { + FT_Pos u_off, d_off; + + + cur_pos1 = FT_PIX_ROUND( org_center ); + + if ( cur_len <= 64 ) + { + u_off = 32; + d_off = 32; + } + else + { + u_off = 38; + d_off = 26; + } + + delta1 = org_center - ( cur_pos1 - u_off ); + if ( delta1 < 0 ) + delta1 = -delta1; + + delta2 = org_center - ( cur_pos1 + d_off ); + if ( delta2 < 0 ) + delta2 = -delta2; + + if ( delta1 < delta2 ) + cur_pos1 -= u_off; + else + cur_pos1 += d_off; + + edge->pos = cur_pos1 - cur_len / 2; + edge2->pos = cur_pos1 + cur_len / 2; + + FT_TRACE5(( " STEM: edge %d (opos=%.2f) linked to %d (opos=%.2f)" + " snapped to %.2f and %.2f\n", + edge - edges, edge->opos / 64.0, + edge2 - edges, edge2->opos / 64.0, + edge->pos / 64.0, edge2->pos / 64.0 )); + } + + else + { + org_pos = anchor->pos + ( edge->opos - anchor->opos ); + org_len = edge2->opos - edge->opos; + org_center = org_pos + ( org_len >> 1 ); + + cur_len = af_latin_compute_stem_width( hints, dim, + org_len, 0, + edge->flags, + edge2->flags ); + + cur_pos1 = FT_PIX_ROUND( org_pos ); + delta1 = cur_pos1 + ( cur_len >> 1 ) - org_center; + if ( delta1 < 0 ) + delta1 = -delta1; + + cur_pos2 = FT_PIX_ROUND( org_pos + org_len ) - cur_len; + delta2 = cur_pos2 + ( cur_len >> 1 ) - org_center; + if ( delta2 < 0 ) + delta2 = -delta2; + + edge->pos = ( delta1 < delta2 ) ? cur_pos1 : cur_pos2; + edge2->pos = edge->pos + cur_len; + + FT_TRACE5(( " STEM: edge %d (opos=%.2f) linked to %d (opos=%.2f)" + " snapped to %.2f and %.2f\n", + edge - edges, edge->opos / 64.0, + edge2 - edges, edge2->opos / 64.0, + edge->pos / 64.0, edge2->pos / 64.0 )); + } + +#ifdef FT_DEBUG_LEVEL_TRACE + num_actions++; +#endif + + edge->flags |= AF_EDGE_DONE; + edge2->flags |= AF_EDGE_DONE; + + if ( edge > edges && + ( top_to_bottom_hinting ? ( edge->pos > edge[-1].pos ) + : ( edge->pos < edge[-1].pos ) ) ) + { + /* don't move if stem would (almost) disappear otherwise; */ + /* the ad-hoc value 16 corresponds to 1/4px */ + if ( edge->link && FT_ABS( edge->link->pos - edge[-1].pos ) > 16 ) + { +#ifdef FT_DEBUG_LEVEL_TRACE + FT_TRACE5(( " BOUND: edge %d (pos=%.2f) moved to %.2f\n", + edge - edges, + edge->pos / 64.0, + edge[-1].pos / 64.0 )); + + num_actions++; +#endif + + edge->pos = edge[-1].pos; + } + } + } + } + + /* make sure that lowercase m's maintain their symmetry */ + + /* In general, lowercase m's have six vertical edges if they are sans */ + /* serif, or twelve if they are with serifs. This implementation is */ + /* based on that assumption, and seems to work very well with most */ + /* faces. However, if for a certain face this assumption is not */ + /* true, the m is just rendered like before. In addition, any stem */ + /* correction will only be applied to symmetrical glyphs (even if the */ + /* glyph is not an m), so the potential for unwanted distortion is */ + /* relatively low. */ + + /* We don't handle horizontal edges since we can't easily assure that */ + /* the third (lowest) stem aligns with the base line; it might end up */ + /* one pixel higher or lower. */ + + n_edges = edge_limit - edges; + if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) ) + { + AF_Edge edge1, edge2, edge3; + FT_Pos dist1, dist2, span, delta; + + + if ( n_edges == 6 ) + { + edge1 = edges; + edge2 = edges + 2; + edge3 = edges + 4; + } + else + { + edge1 = edges + 1; + edge2 = edges + 5; + edge3 = edges + 9; + } + + dist1 = edge2->opos - edge1->opos; + dist2 = edge3->opos - edge2->opos; + + span = dist1 - dist2; + if ( span < 0 ) + span = -span; + + if ( span < 8 ) + { + delta = edge3->pos - ( 2 * edge2->pos - edge1->pos ); + edge3->pos -= delta; + if ( edge3->link ) + edge3->link->pos -= delta; + + /* move the serifs along with the stem */ + if ( n_edges == 12 ) + { + ( edges + 8 )->pos -= delta; + ( edges + 11 )->pos -= delta; + } + + edge3->flags |= AF_EDGE_DONE; + if ( edge3->link ) + edge3->link->flags |= AF_EDGE_DONE; + } + } + + if ( has_serifs || !anchor ) + { + /* + * now hint the remaining edges (serifs and single) in order + * to complete our processing + */ + for ( edge = edges; edge < edge_limit; edge++ ) + { + FT_Pos delta; + + + if ( edge->flags & AF_EDGE_DONE ) + continue; + + delta = 1000; + + if ( edge->serif ) + { + delta = edge->serif->opos - edge->opos; + if ( delta < 0 ) + delta = -delta; + } + + if ( delta < 64 + 16 ) + { + af_latin_align_serif_edge( hints, edge->serif, edge ); + FT_TRACE5(( " SERIF: edge %d (opos=%.2f) serif to %d (opos=%.2f)" + " aligned to %.2f\n", + edge - edges, edge->opos / 64.0, + edge->serif - edges, edge->serif->opos / 64.0, + edge->pos / 64.0 )); + } + else if ( !anchor ) + { + edge->pos = FT_PIX_ROUND( edge->opos ); + anchor = edge; + FT_TRACE5(( " SERIF_ANCHOR: edge %d (opos=%.2f)" + " snapped to %.2f\n", + edge-edges, edge->opos / 64.0, edge->pos / 64.0 )); + } + else + { + AF_Edge before, after; + + + for ( before = edge - 1; before >= edges; before-- ) + if ( before->flags & AF_EDGE_DONE ) + break; + + for ( after = edge + 1; after < edge_limit; after++ ) + if ( after->flags & AF_EDGE_DONE ) + break; + + if ( before >= edges && before < edge && + after < edge_limit && after > edge ) + { + if ( after->opos == before->opos ) + edge->pos = before->pos; + else + edge->pos = before->pos + + FT_MulDiv( edge->opos - before->opos, + after->pos - before->pos, + after->opos - before->opos ); + + FT_TRACE5(( " SERIF_LINK1: edge %d (opos=%.2f) snapped to %.2f" + " from %d (opos=%.2f)\n", + edge - edges, edge->opos / 64.0, + edge->pos / 64.0, + before - edges, before->opos / 64.0 )); + } + else + { + edge->pos = anchor->pos + + ( ( edge->opos - anchor->opos + 16 ) & ~31 ); + FT_TRACE5(( " SERIF_LINK2: edge %d (opos=%.2f)" + " snapped to %.2f\n", + edge - edges, edge->opos / 64.0, edge->pos / 64.0 )); + } + } + +#ifdef FT_DEBUG_LEVEL_TRACE + num_actions++; +#endif + edge->flags |= AF_EDGE_DONE; + + if ( edge > edges && + ( top_to_bottom_hinting ? ( edge->pos > edge[-1].pos ) + : ( edge->pos < edge[-1].pos ) ) ) + { + /* don't move if stem would (almost) disappear otherwise; */ + /* the ad-hoc value 16 corresponds to 1/4px */ + if ( edge->link && FT_ABS( edge->link->pos - edge[-1].pos ) > 16 ) + { +#ifdef FT_DEBUG_LEVEL_TRACE + FT_TRACE5(( " BOUND: edge %d (pos=%.2f) moved to %.2f\n", + edge - edges, + edge->pos / 64.0, + edge[-1].pos / 64.0 )); + + num_actions++; +#endif + edge->pos = edge[-1].pos; + } + } + + if ( edge + 1 < edge_limit && + edge[1].flags & AF_EDGE_DONE && + ( top_to_bottom_hinting ? ( edge->pos < edge[1].pos ) + : ( edge->pos > edge[1].pos ) ) ) + { + /* don't move if stem would (almost) disappear otherwise; */ + /* the ad-hoc value 16 corresponds to 1/4px */ + if ( edge->link && FT_ABS( edge->link->pos - edge[-1].pos ) > 16 ) + { +#ifdef FT_DEBUG_LEVEL_TRACE + FT_TRACE5(( " BOUND: edge %d (pos=%.2f) moved to %.2f\n", + edge - edges, + edge->pos / 64.0, + edge[1].pos / 64.0 )); + + num_actions++; +#endif + + edge->pos = edge[1].pos; + } + } + } + } + +#ifdef FT_DEBUG_LEVEL_TRACE + if ( !num_actions ) + FT_TRACE5(( " (none)\n" )); + FT_TRACE5(( "\n" )); +#endif + } + + + /* Apply the complete hinting algorithm to a latin glyph. */ + + static FT_Error + af_latin_hints_apply( FT_UInt glyph_index, + AF_GlyphHints hints, + FT_Outline* outline, + AF_LatinMetrics metrics ) + { + FT_Error error; + int dim; + + AF_LatinAxis axis; + + + error = af_glyph_hints_reload( hints, outline ); + if ( error ) + goto Exit; + + /* analyze glyph outline */ + if ( AF_HINTS_DO_HORIZONTAL( hints ) ) + { + axis = &metrics->axis[AF_DIMENSION_HORZ]; + error = af_latin_hints_detect_features( hints, + axis->width_count, + axis->widths, + AF_DIMENSION_HORZ ); + if ( error ) + goto Exit; + } + + if ( AF_HINTS_DO_VERTICAL( hints ) ) + { + axis = &metrics->axis[AF_DIMENSION_VERT]; + error = af_latin_hints_detect_features( hints, + axis->width_count, + axis->widths, + AF_DIMENSION_VERT ); + if ( error ) + goto Exit; + + /* apply blue zones to base characters only */ + if ( !( metrics->root.globals->glyph_styles[glyph_index] & AF_NONBASE ) ) + af_latin_hints_compute_blue_edges( hints, metrics ); + } + + /* grid-fit the outline */ + for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) + { +#ifdef AF_CONFIG_OPTION_USE_WARPER + if ( dim == AF_DIMENSION_HORZ && + metrics->root.scaler.render_mode == FT_RENDER_MODE_NORMAL && + AF_HINTS_DO_WARP( hints ) ) + { + AF_WarperRec warper; + FT_Fixed scale; + FT_Pos delta; + + + af_warper_compute( &warper, hints, (AF_Dimension)dim, + &scale, &delta ); + af_glyph_hints_scale_dim( hints, (AF_Dimension)dim, + scale, delta ); + continue; + } +#endif /* AF_CONFIG_OPTION_USE_WARPER */ + + if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) || + ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) ) ) + { + af_latin_hint_edges( hints, (AF_Dimension)dim ); + af_glyph_hints_align_edge_points( hints, (AF_Dimension)dim ); + af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim ); + af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim ); + } + } + + af_glyph_hints_save( hints, outline ); + + Exit: + return error; + } + + + /*************************************************************************/ + /*************************************************************************/ + /***** *****/ + /***** L A T I N S C R I P T C L A S S *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + + + AF_DEFINE_WRITING_SYSTEM_CLASS( + af_latin_writing_system_class, + + AF_WRITING_SYSTEM_LATIN, + + sizeof ( AF_LatinMetricsRec ), + + (AF_WritingSystem_InitMetricsFunc) af_latin_metrics_init, /* style_metrics_init */ + (AF_WritingSystem_ScaleMetricsFunc)af_latin_metrics_scale, /* style_metrics_scale */ + (AF_WritingSystem_DoneMetricsFunc) NULL, /* style_metrics_done */ + (AF_WritingSystem_GetStdWidthsFunc)af_latin_get_standard_widths, /* style_metrics_getstdw */ + + (AF_WritingSystem_InitHintsFunc) af_latin_hints_init, /* style_hints_init */ + (AF_WritingSystem_ApplyHintsFunc) af_latin_hints_apply /* style_hints_apply */ + ) + + +/* END */ |