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kc3-lang/freetype/src/type1/t1afm.c
Werner Lemberg
- src/type1/t1afm.c
-
/**************************************************************************** * * t1afm.c * * AFM support for Type 1 fonts (body). * * Copyright (C) 1996-2023 by * David Turner, Robert Wilhelm, and Werner Lemberg. * * This file is part of the FreeType project, and may only be used, * modified, and distributed under the terms of the FreeType project * license, LICENSE.TXT. By continuing to use, modify, or distribute * this file you indicate that you have read the license and * understand and accept it fully. * */ #include "t1afm.h" #include <freetype/internal/ftdebug.h> #include <freetype/internal/ftstream.h> #include <freetype/internal/psaux.h> #include "t1errors.h" #ifndef T1_CONFIG_OPTION_NO_AFM /************************************************************************** * * 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 t1afm FT_LOCAL_DEF( void ) T1_Done_Metrics( FT_Memory memory, AFM_FontInfo fi ) { FT_FREE( fi->KernPairs ); fi->NumKernPair = 0; FT_FREE( fi->TrackKerns ); fi->NumTrackKern = 0; FT_FREE( fi ); } /* read a glyph name and return the equivalent glyph index */ static FT_Int t1_get_index( const char* name, FT_Offset len, void* user_data ) { T1_Font type1 = (T1_Font)user_data; FT_Int n; /* PS string/name length must be < 16-bit */ if ( len > 0xFFFFU ) return 0; for ( n = 0; n < type1->num_glyphs; n++ ) { char* gname = (char*)type1->glyph_names[n]; if ( gname && gname[0] == name[0] && ft_strlen( gname ) == len && ft_strncmp( gname, name, len ) == 0 ) return n; } return 0; } #undef KERN_INDEX #define KERN_INDEX( g1, g2 ) ( ( (FT_ULong)(g1) << 16 ) | (g2) ) /* compare two kerning pairs */ FT_COMPARE_DEF( int ) compare_kern_pairs( const void* a, const void* b ) { AFM_KernPair pair1 = (AFM_KernPair)a; AFM_KernPair pair2 = (AFM_KernPair)b; FT_ULong index1 = KERN_INDEX( pair1->index1, pair1->index2 ); FT_ULong index2 = KERN_INDEX( pair2->index1, pair2->index2 ); if ( index1 > index2 ) return 1; else if ( index1 < index2 ) return -1; else return 0; } /* parse a PFM file -- for now, only read the kerning pairs */ static FT_Error T1_Read_PFM( FT_Face t1_face, FT_Stream stream, AFM_FontInfo fi ) { FT_Error error = FT_Err_Ok; FT_Memory memory = stream->memory; FT_Byte* start; FT_Byte* limit; FT_Byte* p; AFM_KernPair kp; FT_Int width_table_length; FT_CharMap oldcharmap; FT_CharMap charmap; FT_Int n; start = (FT_Byte*)stream->cursor; limit = (FT_Byte*)stream->limit; /* Figure out how long the width table is. */ /* This info is a little-endian short at offset 99. */ p = start + 99; if ( p + 2 > limit ) { error = FT_THROW( Unknown_File_Format ); goto Exit; } width_table_length = FT_PEEK_USHORT_LE( p ); p += 18 + width_table_length; if ( p + 0x12 > limit || FT_PEEK_USHORT_LE( p ) < 0x12 ) /* extension table is probably optional */ goto Exit; /* Kerning offset is 14 bytes from start of extensions table. */ p += 14; p = start + FT_PEEK_ULONG_LE( p ); if ( p == start ) /* zero offset means no table */ goto Exit; if ( p + 2 > limit ) { error = FT_THROW( Unknown_File_Format ); goto Exit; } fi->NumKernPair = FT_PEEK_USHORT_LE( p ); p += 2; if ( p + 4 * fi->NumKernPair > limit ) { error = FT_THROW( Unknown_File_Format ); goto Exit; } /* Actually, kerning pairs are simply optional! */ if ( fi->NumKernPair == 0 ) goto Exit; /* allocate the pairs */ if ( FT_QNEW_ARRAY( fi->KernPairs, fi->NumKernPair ) ) goto Exit; /* now, read each kern pair */ kp = fi->KernPairs; limit = p + 4 * fi->NumKernPair; /* PFM kerning data are stored by encoding rather than glyph index, */ /* so find the PostScript charmap of this font and install it */ /* temporarily. If we find no PostScript charmap, then just use */ /* the default and hope it is the right one. */ oldcharmap = t1_face->charmap; for ( n = 0; n < t1_face->num_charmaps; n++ ) { charmap = t1_face->charmaps[n]; /* check against PostScript pseudo platform */ if ( charmap->platform_id == 7 ) { t1_face->charmap = charmap; break; } } /* Kerning info is stored as: */ /* */ /* encoding of first glyph (1 byte) */ /* encoding of second glyph (1 byte) */ /* offset (little-endian short) */ for ( ; p < limit; p += 4 ) { kp->index1 = FT_Get_Char_Index( t1_face, p[0] ); kp->index2 = FT_Get_Char_Index( t1_face, p[1] ); kp->x = (FT_Int)FT_PEEK_SHORT_LE( p + 2 ); kp->y = 0; kp++; } t1_face->charmap = oldcharmap; /* now, sort the kern pairs according to their glyph indices */ ft_qsort( fi->KernPairs, fi->NumKernPair, sizeof ( AFM_KernPairRec ), compare_kern_pairs ); Exit: if ( error ) { FT_FREE( fi->KernPairs ); fi->NumKernPair = 0; } return error; } /* parse a metrics file -- either AFM or PFM depending on what */ /* it turns out to be */ FT_LOCAL_DEF( FT_Error ) T1_Read_Metrics( FT_Face t1_face, FT_Stream stream ) { PSAux_Service psaux; FT_Memory memory = stream->memory; AFM_ParserRec parser; AFM_FontInfo fi = NULL; FT_Error error = FT_ERR( Unknown_File_Format ); T1_Face face = (T1_Face)t1_face; T1_Font t1_font = &face->type1; if ( face->afm_data ) { FT_TRACE1(( "T1_Read_Metrics:" " Freeing previously attached metrics data.\n" )); T1_Done_Metrics( memory, (AFM_FontInfo)face->afm_data ); face->afm_data = NULL; } if ( FT_NEW( fi ) || FT_FRAME_ENTER( stream->size ) ) goto Exit; fi->FontBBox = t1_font->font_bbox; fi->Ascender = t1_font->font_bbox.yMax; fi->Descender = t1_font->font_bbox.yMin; psaux = (PSAux_Service)face->psaux; if ( psaux->afm_parser_funcs ) { error = psaux->afm_parser_funcs->init( &parser, stream->memory, stream->cursor, stream->limit ); if ( !error ) { parser.FontInfo = fi; parser.get_index = t1_get_index; parser.user_data = t1_font; error = psaux->afm_parser_funcs->parse( &parser ); psaux->afm_parser_funcs->done( &parser ); } } if ( FT_ERR_EQ( error, Unknown_File_Format ) ) { FT_Byte* start = stream->cursor; /* MS Windows allows versions up to 0x3FF without complaining */ if ( stream->size > 6 && start[1] < 4 && FT_PEEK_ULONG_LE( start + 2 ) == stream->size ) error = T1_Read_PFM( t1_face, stream, fi ); } if ( !error ) { t1_font->font_bbox = fi->FontBBox; t1_face->bbox.xMin = fi->FontBBox.xMin >> 16; t1_face->bbox.yMin = fi->FontBBox.yMin >> 16; /* no `U' suffix here to 0xFFFF! */ t1_face->bbox.xMax = ( fi->FontBBox.xMax + 0xFFFF ) >> 16; t1_face->bbox.yMax = ( fi->FontBBox.yMax + 0xFFFF ) >> 16; /* ascender and descender are optional and could both be zero */ /* check if values are meaningful before overriding defaults */ if ( fi->Ascender > fi->Descender ) { /* no `U' suffix here to 0x8000! */ t1_face->ascender = (FT_Short)( ( fi->Ascender + 0x8000 ) >> 16 ); t1_face->descender = (FT_Short)( ( fi->Descender + 0x8000 ) >> 16 ); } if ( fi->NumKernPair ) { t1_face->face_flags |= FT_FACE_FLAG_KERNING; face->afm_data = fi; fi = NULL; } } FT_FRAME_EXIT(); Exit: if ( fi ) T1_Done_Metrics( memory, fi ); return error; } /* find the kerning for a given glyph pair */ FT_LOCAL_DEF( void ) T1_Get_Kerning( AFM_FontInfo fi, FT_UInt glyph1, FT_UInt glyph2, FT_Vector* kerning ) { AFM_KernPair min, mid, max; FT_ULong idx = KERN_INDEX( glyph1, glyph2 ); /* simple binary search */ min = fi->KernPairs; max = min + fi->NumKernPair - 1; while ( min <= max ) { FT_ULong midi; mid = min + ( max - min ) / 2; midi = KERN_INDEX( mid->index1, mid->index2 ); if ( midi == idx ) { kerning->x = mid->x; kerning->y = mid->y; return; } if ( midi < idx ) min = mid + 1; else max = mid - 1; } kerning->x = 0; kerning->y = 0; } FT_LOCAL_DEF( FT_Error ) T1_Get_Track_Kerning( FT_Face face, FT_Fixed ptsize, FT_Int degree, FT_Fixed* kerning ) { AFM_FontInfo fi = (AFM_FontInfo)( (T1_Face)face )->afm_data; FT_UInt i; if ( !fi ) return FT_THROW( Invalid_Argument ); for ( i = 0; i < fi->NumTrackKern; i++ ) { AFM_TrackKern tk = fi->TrackKerns + i; if ( tk->degree != degree ) continue; if ( ptsize < tk->min_ptsize ) *kerning = tk->min_kern; else if ( ptsize > tk->max_ptsize ) *kerning = tk->max_kern; else { *kerning = FT_MulDiv( ptsize - tk->min_ptsize, tk->max_kern - tk->min_kern, tk->max_ptsize - tk->min_ptsize ) + tk->min_kern; } } return FT_Err_Ok; } #else /* T1_CONFIG_OPTION_NO_AFM */ /* ANSI C doesn't like empty source files */ typedef int t1_afm_dummy_; #endif /* T1_CONFIG_OPTION_NO_AFM */ /* END */