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Diffstat (limited to 'nx-X11/extras/freetype2/src/autohint/ahglobal.c')
| -rw-r--r-- | nx-X11/extras/freetype2/src/autohint/ahglobal.c | 402 |
1 files changed, 402 insertions, 0 deletions
diff --git a/nx-X11/extras/freetype2/src/autohint/ahglobal.c b/nx-X11/extras/freetype2/src/autohint/ahglobal.c new file mode 100644 index 000000000..e157014b5 --- /dev/null +++ b/nx-X11/extras/freetype2/src/autohint/ahglobal.c @@ -0,0 +1,402 @@ +/***************************************************************************/ +/* */ +/* ahglobal.c */ +/* */ +/* Routines used to compute global metrics automatically (body). */ +/* */ +/* Copyright 2000-2001, 2002, 2003, 2004 Catharon Productions Inc. */ +/* Author: David Turner */ +/* */ +/* This file is part of the Catharon Typography Project and shall only */ +/* be used, modified, and distributed under the terms of the Catharon */ +/* Open Source License that should come with this file under the name */ +/* `CatharonLicense.txt'. By continuing to use, modify, or distribute */ +/* this file you indicate that you have read the license and */ +/* understand and accept it fully. */ +/* */ +/* Note that this license is compatible with the FreeType license. */ +/* */ +/***************************************************************************/ + + +#include <ft2build.h> +#include FT_INTERNAL_DEBUG_H +#include "ahglobal.h" +#include "ahglyph.h" + + +#define MAX_TEST_CHARACTERS 12 + + /* cf. AH_BLUE_XXX constants in ahtypes.h */ + + static + const char* const blue_chars[AH_BLUE_MAX] = + { + "THEZOCQS", + "HEZLOCUS", +#ifdef FT_CONFIG_CHESTER_SMALL_F + "fijkdbh", +#endif + "xzroesc", + "xzroesc", + "pqgjy" + }; + + + /* simple insertion sort */ + static void + sort_values( FT_Int count, + FT_Pos* table ) + { + FT_Int i, j; + FT_Pos swap; + + + for ( i = 1; i < count; i++ ) + { + for ( j = i; j > 0; j-- ) + { + if ( table[j] > table[j - 1] ) + break; + + swap = table[j]; + table[j] = table[j - 1]; + table[j - 1] = swap; + } + } + } + + + static FT_Error + ah_hinter_compute_blues( AH_Hinter hinter ) + { + AH_Blue blue; + AH_Globals globals = &hinter->globals->design; + FT_Pos flats [MAX_TEST_CHARACTERS]; + FT_Pos rounds[MAX_TEST_CHARACTERS]; + FT_Int num_flats; + FT_Int num_rounds; + + FT_Face face; + FT_GlyphSlot glyph; + FT_Error error; + FT_CharMap charmap; + + + face = hinter->face; + glyph = face->glyph; + + /* save current charmap */ + charmap = face->charmap; + + /* do we have a Unicode charmap in there? */ + error = FT_Select_Charmap( face, FT_ENCODING_UNICODE ); + if ( error ) + goto Exit; + + /* we compute the blues simply by loading each character from the */ + /* `blue_chars[blues]' string, then compute its top-most or */ + /* bottom-most points (depending on `AH_IS_TOP_BLUE') */ + + AH_LOG(( "blue zones computation\n" )); + AH_LOG(( "------------------------------------------------\n" )); + + for ( blue = AH_BLUE_CAPITAL_TOP; blue < AH_BLUE_MAX; blue++ ) + { + const char* p = blue_chars[blue]; + const char* limit = p + MAX_TEST_CHARACTERS; + + FT_Pos *blue_ref, *blue_shoot; + + + AH_LOG(( "blue %3d: ", blue )); + + num_flats = 0; + num_rounds = 0; + + for ( ; p < limit; p++ ) + { + FT_UInt glyph_index; + FT_Vector* extremum; + FT_Vector* points; + FT_Vector* point_limit; + FT_Vector* point; + FT_Bool round; + + + /* exit if we reach the end of the string */ + if ( !*p ) + break; + + AH_LOG(( "`%c'", *p )); + + /* load the character in the face -- skip unknown or empty ones */ + glyph_index = FT_Get_Char_Index( face, (FT_UInt)*p ); + if ( glyph_index == 0 ) + continue; + + error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); + if ( error || glyph->outline.n_points <= 0 ) + continue; + + /* now compute min or max point indices and coordinates */ + points = glyph->outline.points; + point_limit = points + glyph->outline.n_points; + point = points; + extremum = point; + point++; + + if ( AH_IS_TOP_BLUE( blue ) ) + { + for ( ; point < point_limit; point++ ) + if ( point->y > extremum->y ) + extremum = point; + } + else + { + for ( ; point < point_limit; point++ ) + if ( point->y < extremum->y ) + extremum = point; + } + + AH_LOG(( "%5d", (int)extremum->y )); + + /* now, check whether the point belongs to a straight or round */ + /* segment; we first need to find in which contour the extremum */ + /* lies, then see its previous and next points */ + { + FT_Int idx = (FT_Int)( extremum - points ); + FT_Int n; + FT_Int first, last, prev, next, end; + FT_Pos dist; + + + last = -1; + first = 0; + + for ( n = 0; n < glyph->outline.n_contours; n++ ) + { + end = glyph->outline.contours[n]; + if ( end >= idx ) + { + last = end; + break; + } + first = end + 1; + } + + /* XXX: should never happen! */ + if ( last < 0 ) + continue; + + /* now look for the previous and next points that are not on the */ + /* same Y coordinate. Threshold the `closeness'... */ + + prev = idx; + next = prev; + + do + { + if ( prev > first ) + prev--; + else + prev = last; + + dist = points[prev].y - extremum->y; + if ( dist < -5 || dist > 5 ) + break; + + } while ( prev != idx ); + + do + { + if ( next < last ) + next++; + else + next = first; + + dist = points[next].y - extremum->y; + if ( dist < -5 || dist > 5 ) + break; + + } while ( next != idx ); + + /* now, set the `round' flag depending on the segment's kind */ + round = FT_BOOL( + FT_CURVE_TAG( glyph->outline.tags[prev] ) != FT_CURVE_TAG_ON || + FT_CURVE_TAG( glyph->outline.tags[next] ) != FT_CURVE_TAG_ON ); + + AH_LOG(( "%c ", round ? 'r' : 'f' )); + } + + if ( round ) + rounds[num_rounds++] = extremum->y; + else + flats[num_flats++] = extremum->y; + } + + AH_LOG(( "\n" )); + + /* 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 */ + sort_values( num_rounds, rounds ); + sort_values( num_flats, flats ); + + blue_ref = globals->blue_refs + blue; + blue_shoot = globals->blue_shoots + blue; + if ( num_flats == 0 && num_rounds == 0 ) + { + *blue_ref = -10000; + *blue_shoot = -10000; + } + else 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 ( AH_IS_TOP_BLUE( blue ) ^ over_ref ) + *blue_shoot = *blue_ref = ( shoot + ref ) / 2; + } + + AH_LOG(( "-- ref = %ld, shoot = %ld\n", *blue_ref, *blue_shoot )); + } + + /* reset original face charmap */ + FT_Set_Charmap( face, charmap ); + error = 0; + + Exit: + return error; + } + + + static FT_Error + ah_hinter_compute_widths( AH_Hinter hinter ) + { + /* scan the array of segments in each direction */ + AH_Outline outline = hinter->glyph; + AH_Segment segments; + AH_Segment limit; + AH_Globals globals = &hinter->globals->design; + FT_Pos* widths; + FT_Int dimension; + FT_Int* p_num_widths; + FT_Error error = 0; + FT_Pos edge_distance_threshold = 32000; + + + globals->num_widths = 0; + globals->num_heights = 0; + + /* For now, compute the standard width and height from the `o' */ + /* character. I started computing the stem width of the `i' and the */ + /* stem height of the "-", but it wasn't too good. Moreover, we now */ + /* have a single character that gives us standard width and height. */ + { + FT_UInt glyph_index; + + + glyph_index = FT_Get_Char_Index( hinter->face, 'o' ); + if ( glyph_index == 0 ) + return 0; + + error = FT_Load_Glyph( hinter->face, glyph_index, FT_LOAD_NO_SCALE ); + if ( error ) + goto Exit; + + error = ah_outline_load( hinter->glyph, 0x10000L, 0x10000L, + hinter->face ); + if ( error ) + goto Exit; + + ah_outline_compute_segments( hinter->glyph ); + ah_outline_link_segments( hinter->glyph ); + } + + segments = outline->horz_segments; + limit = segments + outline->num_hsegments; + widths = globals->heights; + p_num_widths = &globals->num_heights; + + for ( dimension = 1; dimension >= 0; dimension-- ) + { + AH_Segment seg = segments; + AH_Segment link; + FT_Int num_widths = 0; + + + 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 < AH_MAX_WIDTHS ) + widths[num_widths++] = dist; + } + } + + sort_values( num_widths, widths ); + *p_num_widths = num_widths; + + /* we will now try to find the smallest width */ + if ( num_widths > 0 && widths[0] < edge_distance_threshold ) + edge_distance_threshold = widths[0]; + + segments = outline->vert_segments; + limit = segments + outline->num_vsegments; + widths = globals->widths; + p_num_widths = &globals->num_widths; + } + + /* Now, compute the edge distance threshold as a fraction of the */ + /* smallest width in the font. Set it in `hinter->glyph' too! */ + if ( edge_distance_threshold == 32000 ) + edge_distance_threshold = 50; + + /* let's try 20% */ + hinter->glyph->edge_distance_threshold = edge_distance_threshold / 5; + + Exit: + return error; + } + + + FT_LOCAL_DEF( FT_Error ) + ah_hinter_compute_globals( AH_Hinter hinter ) + { + return ah_hinter_compute_widths( hinter ) || + ah_hinter_compute_blues ( hinter ); + } + + +/* END */ |