diff options
Diffstat (limited to 'src/freetype/ttmtx.c')
| -rw-r--r-- | src/freetype/ttmtx.c | 289 |
1 files changed, 289 insertions, 0 deletions
diff --git a/src/freetype/ttmtx.c b/src/freetype/ttmtx.c new file mode 100644 index 0000000..7eaeba8 --- /dev/null +++ b/src/freetype/ttmtx.c @@ -0,0 +1,289 @@ +/***************************************************************************/ +/* */ +/* ttmtx.c */ +/* */ +/* Load the metrics tables common to TTF and OTF fonts (body). */ +/* */ +/* Copyright 2006-2018 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" + + + /* IMPORTANT: The TT_HoriHeader and TT_VertHeader structures should */ + /* be identical except for the names of their fields, */ + /* which are different. */ + /* */ + /* This ensures that `tt_face_load_hmtx' is able to read */ + /* both the horizontal and vertical headers. */ + + + /*************************************************************************/ + /* */ + /* 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 + + + /*************************************************************************/ + /* */ + /* <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. */ + /* */ + 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; + } + + + /*************************************************************************/ + /* */ + /* <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; + + static 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> */ + /* Return the horizontal or vertical metrics in font units for a */ + /* given glyph. The values are the left side bearing (top side */ + /* bearing for vertical metrics) and advance width (advance height */ + /* for vertical metrics). */ + /* */ + /* <Input> */ + /* face :: A pointer to the TrueType face structure. */ + /* */ + /* vertical :: If set to TRUE, get vertical metrics. */ + /* */ + /* gindex :: The glyph index. */ + /* */ + /* <Output> */ + /* abearing :: The bearing, either left side or top side. */ + /* */ + /* aadvance :: The advance width or advance height, depending on */ + /* the `vertical' flag. */ + /* */ + FT_LOCAL_DEF( void ) + 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; + } + } + + +/* END */ |