/***************************************************************************/ /* */ /* ttmtx.c */ /* */ /* Load the metrics tables common to TTF and OTF fonts (body). */ /* */ /* Copyright 2006 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 #include FT_INTERNAL_DEBUG_H #include FT_INTERNAL_STREAM_H #include FT_TRUETYPE_TAGS_H #include "ttmtx.h" #include "sferrors.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_ttmtx /*************************************************************************/ /* */ /* */ /* tt_face_load_hmtx */ /* */ /* */ /* Load the `hmtx' or `vmtx' table into a face object. */ /* */ /* */ /* face :: A handle to the target face object. */ /* */ /* stream :: The input stream. */ /* */ /* vertical :: A boolean flag. If set, load `vmtx'. */ /* */ /* */ /* FreeType error code. 0 means success. */ /* */ #ifdef FT_OPTIMIZE_MEMORY static FT_Error tt_face_load_hmtx( TT_Face face, FT_Stream stream, FT_Bool vertical ) { FT_Error error; FT_ULong table_size; FT_Byte** ptable; FT_ULong* ptable_size; FT_TRACE2(( "TT_Load_%s_Metrics: %08p\n", vertical ? "Vertical" : "Horizontal", face )); if ( vertical ) { ptable = &face->vert_metrics; ptable_size = &face->vert_metrics_size; /* The table is optional, quit silently if it wasn't found. */ /* */ /* XXX: Some fonts have a valid vertical header with a non-null */ /* `number_of_VMetrics' fields, but no corresponding `vmtx' */ /* table to get the metrics from (e.g. mingliu). */ /* */ /* For safety, we set the field to 0! */ /* */ error = face->goto_table( face, TTAG_vmtx, stream, &table_size ); if ( error ) { /* Set number_Of_VMetrics to 0! */ FT_TRACE2(( " no vertical header in file.\n" )); error = SFNT_Err_Ok; goto Exit; } } else { ptable = &face->horz_metrics; ptable_size = &face->horz_metrics_size; error = face->goto_table( face, TTAG_hmtx, stream, &table_size ); if ( error ) { #ifdef FT_CONFIG_OPTION_INCREMENTAL /* If this is an incrementally loaded font and there are */ /* overriding metrics, tolerate a missing `hmtx' table. */ if ( face->root.internal->incremental_interface && face->root.internal->incremental_interface->funcs-> get_glyph_metrics ) { face->horizontal.number_Of_HMetrics = 0; error = SFNT_Err_Ok; goto Exit; } #endif FT_ERROR(( " no horizontal metrics in file!\n" )); error = SFNT_Err_Hmtx_Table_Missing; goto Exit; } } if ( FT_FRAME_EXTRACT( table_size, *ptable ) ) goto Exit; *ptable_size = table_size; Exit: return error; } #else /* !OPTIMIZE_MEMORY */ static FT_Error tt_face_load_hmtx( TT_Face face, FT_Stream stream, FT_Bool vertical ) { FT_Error error; FT_Memory memory = stream->memory; FT_ULong table_len; FT_Long num_shorts, num_longs, num_shorts_checked; TT_LongMetrics * longs; TT_ShortMetrics** shorts; FT_TRACE2(( "TT_Load_%s_Metrics: %08p\n", vertical ? "Vertical" : "Horizontal", face )); if ( vertical ) { /* The table is optional, quit silently if it wasn't found. */ /* */ /* XXX: Some fonts have a valid vertical header with a non-null */ /* `number_of_VMetrics' fields, but no corresponding `vmtx' */ /* table to get the metrics from (e.g. mingliu). */ /* */ /* For safety, we set the field to 0! */ /* */ error = face->goto_table( face, TTAG_vmtx, stream, &table_len ); if ( error ) { /* Set number_Of_VMetrics to 0! */ FT_TRACE2(( " no vertical header in file.\n" )); face->vertical.number_Of_VMetrics = 0; error = SFNT_Err_Ok; goto Exit; } num_longs = face->vertical.number_Of_VMetrics; longs = (TT_LongMetrics *)&face->vertical.long_metrics; shorts = (TT_ShortMetrics**)&face->vertical.short_metrics; } else { error = face->goto_table( face, TTAG_hmtx, stream, &table_len ); if ( error ) { #ifdef FT_CONFIG_OPTION_INCREMENTAL /* If this is an incrementally loaded font and there are */ /* overriding metrics, tolerate a missing `hmtx' table. */ if ( face->root.internal->incremental_interface && face->root.internal->incremental_interface->funcs-> get_glyph_metrics ) { face->horizontal.number_Of_HMetrics = 0; error = SFNT_Err_Ok; goto Exit; } #endif FT_ERROR(( " no horizontal metrics in file!\n" )); error = SFNT_Err_Hmtx_Table_Missing; goto Exit; } num_longs = face->horizontal.number_Of_HMetrics; longs = (TT_LongMetrics *)&face->horizontal.long_metrics; shorts = (TT_ShortMetrics**)&face->horizontal.short_metrics; } /* never trust derived values */ num_shorts = face->max_profile.numGlyphs - num_longs; num_shorts_checked = ( table_len - num_longs * 4L ) / 2; if ( num_shorts < 0 ) { FT_ERROR(( "TT_Load_%s_Metrics: more metrics than glyphs!\n", vertical ? "Vertical" : "Horizontal" )); /* Adobe simply ignores this problem. So we shall do the same. */ #if 0 error = vertical ? SFNT_Err_Invalid_Vert_Metrics : SFNT_Err_Invalid_Horiz_Metrics; goto Exit; #else num_shorts = 0; #endif } if ( FT_QNEW_ARRAY( *longs, num_longs ) || FT_QNEW_ARRAY( *shorts, num_shorts ) ) goto Exit; if ( FT_FRAME_ENTER( table_len ) ) goto Exit; { TT_LongMetrics cur = *longs; TT_LongMetrics limit = cur + num_longs; for ( ; cur < limit; cur++ ) { cur->advance = FT_GET_USHORT(); cur->bearing = FT_GET_SHORT(); } } /* do we have an inconsistent number of metric values? */ { TT_ShortMetrics* cur = *shorts; TT_ShortMetrics* limit = cur + FT_MIN( num_shorts, num_shorts_checked ); for ( ; cur < limit; cur++ ) *cur = FT_GET_SHORT(); /* We fill up the missing left side bearings with the */ /* last valid value. Since this will occur for buggy CJK */ /* fonts usually only, nothing serious will happen. */ if ( num_shorts > num_shorts_checked && num_shorts_checked > 0 ) { FT_Short val = (*shorts)[num_shorts_checked - 1]; limit = *shorts + num_shorts; for ( ; cur < limit; cur++ ) *cur = val; } } FT_FRAME_EXIT(); FT_TRACE2(( "loaded\n" )); Exit: return error; } #endif /* !FT_OPTIMIZE_METRICS */ /*************************************************************************/ /* */ /* */ /* tt_face_load_hhea */ /* */ /* */ /* Load the `hhea' or 'vhea' table into a face object. */ /* */ /* */ /* face :: A handle to the target face object. */ /* */ /* stream :: The input stream. */ /* */ /* vertical :: A boolean flag. If set, load `vhea'. */ /* */ /* */ /* FreeType error code. 0 means success. */ /* */ FT_LOCAL_DEF( FT_Error ) tt_face_load_hhea( TT_Face face, FT_Stream stream, FT_Bool vertical ) { FT_Error error; TT_HoriHeader* header; const FT_Frame_Field metrics_header_fields[] = { #undef FT_STRUCTURE #define FT_STRUCTURE TT_HoriHeader FT_FRAME_START( 36 ), FT_FRAME_ULONG ( Version ), FT_FRAME_SHORT ( Ascender ), FT_FRAME_SHORT ( Descender ), FT_FRAME_SHORT ( Line_Gap ), FT_FRAME_USHORT( advance_Width_Max ), FT_FRAME_SHORT ( min_Left_Side_Bearing ), FT_FRAME_SHORT ( min_Right_Side_Bearing ), FT_FRAME_SHORT ( xMax_Extent ), FT_FRAME_SHORT ( caret_Slope_Rise ), FT_FRAME_SHORT ( caret_Slope_Run ), FT_FRAME_SHORT ( caret_Offset ), FT_FRAME_SHORT ( Reserved[0] ), FT_FRAME_SHORT ( Reserved[1] ), FT_FRAME_SHORT ( Reserved[2] ), FT_FRAME_SHORT ( Reserved[3] ), FT_FRAME_SHORT ( metric_Data_Format ), FT_FRAME_USHORT( number_Of_HMetrics ), FT_FRAME_END }; FT_TRACE2(( vertical ? "Vertical header " : "Horizontal header " )); if ( vertical ) { face->vertical_info = 0; /* The vertical header table is optional, so return quietly if */ /* we don't find it. */ error = face->goto_table( face, TTAG_vhea, stream, 0 ); if ( error ) { error = SFNT_Err_Ok; goto Exit; } face->vertical_info = 1; header = (TT_HoriHeader*)&face->vertical; } else { /* The horizontal header is mandatory for most fonts; return */ /* an error if we don't find it. */ error = face->goto_table( face, TTAG_hhea, stream, 0 ); if ( error ) { error = SFNT_Err_Horiz_Header_Missing; /* No `hhea' table necessary for SFNT Mac fonts. */ if ( face->format_tag == TTAG_true ) { FT_TRACE2(( "missing. This is an SFNT Mac font.\n")); error = SFNT_Err_Ok; } goto Exit; } header = &face->horizontal; } if ( FT_STREAM_READ_FIELDS( metrics_header_fields, header ) ) goto Exit; header->long_metrics = NULL; header->short_metrics = NULL; FT_TRACE2(( "loaded\n" )); /* Now try to load the corresponding metrics */ error = tt_face_load_hmtx( face, stream, vertical ); Exit: return error; } /*************************************************************************/ /* */ /* */ /* tt_face_get_metrics */ /* */ /* */ /* Returns the horizontal or vertical metrics in font units for a */ /* given glyph. The metrics are the left side bearing (resp. top */ /* side bearing) and advance width (resp. advance height). */ /* */ /* */ /* header :: A pointer to either the horizontal or vertical metrics */ /* structure. */ /* */ /* idx :: The glyph index. */ /* */ /* */ /* bearing :: The bearing, either left side or top side. */ /* */ /* advance :: The advance width resp. advance height. */ /* */ /* */ /* This function will much probably move to another component in the */ /* near future, but I haven't decided which yet. */ /* */ #ifdef FT_OPTIMIZE_MEMORY FT_LOCAL_DEF( FT_Error ) tt_face_get_metrics( TT_Face face, FT_Bool vertical, FT_UInt gindex, FT_Short *abearing, FT_UShort *aadvance ) { TT_HoriHeader* header; FT_Byte* p; FT_Byte* limit; FT_UShort k; if ( vertical ) { header = (TT_HoriHeader*)&face->vertical; p = face->vert_metrics; limit = p + face->vert_metrics_size; } else { header = &face->horizontal; p = face->horz_metrics; limit = p + face->horz_metrics_size; } k = header->number_Of_HMetrics; if ( k > 0 ) { if ( gindex < (FT_UInt)k ) { p += 4 * gindex; if ( p + 4 > limit ) goto NoData; *aadvance = FT_NEXT_USHORT( p ); *abearing = FT_NEXT_SHORT( p ); } else { p += 4 * ( k - 1 ); if ( p + 4 > limit ) goto NoData; *aadvance = FT_NEXT_USHORT( p ); p += 2 + 2 * ( gindex - k ); if ( p + 2 > limit ) *abearing = 0; else *abearing = FT_PEEK_SHORT( p ); } } else { NoData: *abearing = 0; *aadvance = 0; } return SFNT_Err_Ok; } #else /* !FT_OPTIMIZE_MEMORY */ FT_LOCAL_DEF( FT_Error ) tt_face_get_metrics( TT_Face face, FT_Bool vertical, FT_UInt gindex, FT_Short* abearing, FT_UShort* aadvance ) { TT_HoriHeader* header = vertical ? (TT_HoriHeader*)&face->vertical : &face->horizontal; TT_LongMetrics longs_m; FT_UShort k = header->number_Of_HMetrics; if ( k == 0 ) { *abearing = *aadvance = 0; return SFNT_Err_Ok; } if ( gindex < (FT_UInt)k ) { longs_m = (TT_LongMetrics)header->long_metrics + gindex; *abearing = longs_m->bearing; *aadvance = longs_m->advance; } else { *abearing = ((TT_ShortMetrics*)header->short_metrics)[gindex - k]; *aadvance = ((TT_LongMetrics)header->long_metrics)[k - 1].advance; } return SFNT_Err_Ok; } #endif /* !FT_OPTIMIZE_MEMORY */ /* END */