diff options
Diffstat (limited to 'src/type1/t1afm.c')
| -rw-r--r-- | src/type1/t1afm.c | 385 |
1 files changed, 385 insertions, 0 deletions
diff --git a/src/type1/t1afm.c b/src/type1/t1afm.c new file mode 100644 index 0000000..b81a8df --- /dev/null +++ b/src/type1/t1afm.c @@ -0,0 +1,385 @@ +/***************************************************************************/ +/* */ +/* t1afm.c */ +/* */ +/* AFM support for Type 1 fonts (body). */ +/* */ +/* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007 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 "t1afm.h" +#include "t1errors.h" +#include FT_INTERNAL_STREAM_H +#include FT_INTERNAL_POSTSCRIPT_AUX_H + + + /*************************************************************************/ + /* */ + /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ + /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ + /* messages during execution. */ + /* */ +#undef FT_COMPONENT +#define FT_COMPONENT trace_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_UInt len, + void* user_data ) + { + T1_Font type1 = (T1_Font)user_data; + FT_Int n; + + + 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_CALLBACK_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 ); + + + return (int)( index1 - index2 ); + } + + + /* 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 = T1_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; + p = start; + + /* 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 = T1_Err_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 = T1_Err_Unknown_File_Format; + goto Exit; + } + + fi->NumKernPair = FT_PEEK_USHORT_LE( p ); + p += 2; + if ( p + 4 * fi->NumKernPair > limit ) + { + error = T1_Err_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; + charmap = NULL; + + for ( n = 0; n < t1_face->num_charmaps; n++ ) + { + charmap = t1_face->charmaps[n]; + /* check against PostScript pseudo platform */ + if ( charmap->platform_id == 7 ) + { + error = FT_Set_Charmap( t1_face, charmap ); + if ( error ) + goto Exit; + 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++; + } + + if ( oldcharmap != NULL ) + error = FT_Set_Charmap( t1_face, oldcharmap ); + if ( error ) + goto Exit; + + /* 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; + FT_Error error = T1_Err_Unknown_File_Format; + T1_Font t1_font = &( (T1_Face)t1_face )->type1; + + + 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)( (T1_Face)t1_face )->psaux; + if ( psaux && 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 ( error == T1_Err_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; + t1_face->bbox.xMax = ( fi->FontBBox.xMax + 0xFFFFU ) >> 16; + t1_face->bbox.yMax = ( fi->FontBBox.yMax + 0xFFFFU ) >> 16; + + t1_face->ascender = (FT_Short)( ( fi->Ascender + 0x8000U ) >> 16 ); + t1_face->descender = (FT_Short)( ( fi->Descender + 0x8000U ) >> 16 ); + + if ( fi->NumKernPair ) + { + t1_face->face_flags |= FT_FACE_FLAG_KERNING; + ( (T1_Face)t1_face )->afm_data = fi; + fi = NULL; + } + } + + FT_FRAME_EXIT(); + + Exit: + if ( fi != NULL ) + 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_Int i; + + + if ( !fi ) + return T1_Err_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 T1_Err_Ok; + } + + +/* END */ |