ref: 8d463a53d115c45237431965365e5ca03509b4bb
dir: /src/sfnt/ttmtx.c/
/***************************************************************************/
/* */
/* ttmtx.c */
/* */
/* Load the metrics tables common to TTF and OTF fonts (body). */
/* */
/* Copyright 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 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. */
/* */
#if !defined 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 /* !OPTIMIZE_MEMORY || 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 )
{
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 *)&face->vertical.long_metrics;
shorts = (TT_ShortMetrics**)&face->vertical.short_metrics;
}
else
{
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 *)&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(( "%cmtx has more metrics than glyphs.\n" ));
/* 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 /* !OPTIMIZE_MEMORY || 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 )
{
error = face->goto_table( face, TTAG_vhea, stream, 0 );
if ( error )
goto Fail;
header = (TT_HoriHeader*)&face->vertical;
}
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. */
/* */
#if !defined 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 )
{
header = (TT_HoriHeader*)&face->vertical;
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 /* 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 )
{
TT_HoriHeader* header = vertical ? (TT_HoriHeader*)&face->vertical
: &face->horizontal;
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 /* !OPTIMIZE_MEMORY || OLD_INTERNALS */
/* END */