Edit
kc3-lang/freetype/src/sfnt/ttmtx.c
Werner Lemberg
- src/sfnt/ttmtx.c
-
/***************************************************************************/ /* */ /* ttmtx.c */ /* */ /* Load the metrics tables common to TTF and OTF fonts (body). */ /* */ /* Copyright 2006-2009, 2011 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_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 /* * Unfortunately, we can't enable our memory optimizations if * FT_CONFIG_OPTION_OLD_INTERNALS is defined. This is because at least * one rogue client (libXfont in the X.Org XServer) is directly accessing * the metrics. */ /*************************************************************************/ /* */ /* <Function> */ /* tt_face_load_hmtx */ /* */ /* <Description> */ /* Load the `hmtx' or `vmtx' table into a face object. */ /* */ /* <Input> */ /* face :: A handle to the target face object. */ /* */ /* stream :: The input stream. */ /* */ /* vertical :: A boolean flag. If set, load `vmtx'. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ #ifndef FT_CONFIG_OPTION_OLD_INTERNALS FT_LOCAL_DEF( FT_Error ) tt_face_load_hmtx( TT_Face face, FT_Stream stream, FT_Bool vertical ) { FT_Error error; FT_ULong tag, table_size; FT_ULong* ptable_offset; FT_ULong* ptable_size; if ( vertical ) { tag = TTAG_vmtx; ptable_offset = &face->vert_metrics_offset; ptable_size = &face->vert_metrics_size; } else { tag = TTAG_hmtx; ptable_offset = &face->horz_metrics_offset; ptable_size = &face->horz_metrics_size; } error = face->goto_table( face, tag, stream, &table_size ); if ( error ) goto Fail; *ptable_size = table_size; *ptable_offset = FT_STREAM_POS(); Fail: return error; } #else /* !FT_CONFIG_OPTION_OLD_INTERNALS */ FT_LOCAL_DEF( 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_Byte* p; if ( vertical ) { void* lm = &face->vertical.long_metrics; void** sm = &face->vertical.short_metrics; error = face->goto_table( face, TTAG_vmtx, stream, &table_len ); if ( error ) goto Fail; num_longs = face->vertical.number_Of_VMetrics; if ( (FT_ULong)num_longs > table_len / 4 ) num_longs = (FT_Long)( table_len / 4 ); face->vertical.number_Of_VMetrics = 0; longs = (TT_LongMetrics*)lm; shorts = (TT_ShortMetrics**)sm; } else { void* lm = &face->horizontal.long_metrics; void** sm = &face->horizontal.short_metrics; error = face->goto_table( face, TTAG_hmtx, stream, &table_len ); if ( error ) goto Fail; num_longs = face->horizontal.number_Of_HMetrics; if ( (FT_ULong)num_longs > table_len / 4 ) num_longs = (FT_Long)( table_len / 4 ); face->horizontal.number_Of_HMetrics = 0; longs = (TT_LongMetrics*)lm; shorts = (TT_ShortMetrics**)sm; } /* 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_TRACE0(( "tt_face_load_hmtx:" " %cmtx has more metrics than glyphs.\n", vertical ? 'v' : 'h' )); /* 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 Fail; if ( FT_FRAME_ENTER( table_len ) ) goto Fail; p = stream->cursor; { TT_LongMetrics cur = *longs; TT_LongMetrics limit = cur + num_longs; for ( ; cur < limit; cur++ ) { cur->advance = FT_NEXT_USHORT( p ); cur->bearing = FT_NEXT_SHORT( p ); } } /* 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_NEXT_SHORT( p ); /* 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(); if ( vertical ) face->vertical.number_Of_VMetrics = (FT_UShort)num_longs; else face->horizontal.number_Of_HMetrics = (FT_UShort)num_longs; Fail: return error; } #endif /* !FT_CONFIG_OPTION_OLD_INTERNALS */ /*************************************************************************/ /* */ /* <Function> */ /* tt_face_load_hhea */ /* */ /* <Description> */ /* Load the `hhea' or 'vhea' table into a face object. */ /* */ /* <Input> */ /* face :: A handle to the target face object. */ /* */ /* stream :: The input stream. */ /* */ /* vertical :: A boolean flag. If set, load `vhea'. */ /* */ /* <Return> */ /* 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 }; if ( vertical ) { void *v = &face->vertical; error = face->goto_table( face, TTAG_vhea, stream, 0 ); if ( error ) goto Fail; header = (TT_HoriHeader*)v; } else { error = face->goto_table( face, TTAG_hhea, stream, 0 ); if ( error ) goto Fail; header = &face->horizontal; } if ( FT_STREAM_READ_FIELDS( metrics_header_fields, header ) ) goto Fail; FT_TRACE3(( "Ascender: %5d\n", header->Ascender )); FT_TRACE3(( "Descender: %5d\n", header->Descender )); FT_TRACE3(( "number_Of_Metrics: %5u\n", header->number_Of_HMetrics )); header->long_metrics = NULL; header->short_metrics = NULL; Fail: return error; } /*************************************************************************/ /* */ /* <Function> */ /* tt_face_get_metrics */ /* */ /* <Description> */ /* 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). */ /* */ /* <Input> */ /* header :: A pointer to either the horizontal or vertical metrics */ /* structure. */ /* */ /* idx :: The glyph index. */ /* */ /* <Output> */ /* bearing :: The bearing, either left side or top side. */ /* */ /* advance :: The advance width resp. advance height. */ /* */ #ifndef FT_CONFIG_OPTION_OLD_INTERNALS FT_LOCAL_DEF( FT_Error ) tt_face_get_metrics( TT_Face face, FT_Bool vertical, FT_UInt gindex, FT_Short *abearing, FT_UShort *aadvance ) { FT_Error error; FT_Stream stream = face->root.stream; TT_HoriHeader* header; FT_ULong table_pos, table_size, table_end; FT_UShort k; if ( vertical ) { void* v = &face->vertical; header = (TT_HoriHeader*)v; table_pos = face->vert_metrics_offset; table_size = face->vert_metrics_size; } else { header = &face->horizontal; table_pos = face->horz_metrics_offset; table_size = face->horz_metrics_size; } table_end = table_pos + table_size; k = header->number_Of_HMetrics; if ( k > 0 ) { if ( gindex < (FT_UInt)k ) { table_pos += 4 * gindex; if ( table_pos + 4 > table_end ) goto NoData; if ( FT_STREAM_SEEK( table_pos ) || FT_READ_USHORT( *aadvance ) || FT_READ_SHORT( *abearing ) ) goto NoData; } else { table_pos += 4 * ( k - 1 ); if ( table_pos + 4 > table_end ) goto NoData; if ( FT_STREAM_SEEK( table_pos ) || FT_READ_USHORT( *aadvance ) ) goto NoData; table_pos += 4 + 2 * ( gindex - k ); if ( table_pos + 2 > table_end ) *abearing = 0; else { if ( !FT_STREAM_SEEK( table_pos ) ) (void)FT_READ_SHORT( *abearing ); } } } else { NoData: *abearing = 0; *aadvance = 0; } return SFNT_Err_Ok; } #else /* !FT_CONFIG_OPTION_OLD_INTERNALS */ FT_LOCAL_DEF( FT_Error ) tt_face_get_metrics( TT_Face face, FT_Bool vertical, FT_UInt gindex, FT_Short* abearing, FT_UShort* aadvance ) { void* v = &face->vertical; void* h = &face->horizontal; TT_HoriHeader* header = vertical ? (TT_HoriHeader*)v : (TT_HoriHeader*)h; TT_LongMetrics longs_m; FT_UShort k = header->number_Of_HMetrics; if ( k == 0 || !header->long_metrics || gindex >= (FT_UInt)face->max_profile.numGlyphs ) { *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_CONFIG_OPTION_OLD_INTERNALS */ /* END */