tt_face_load_any( TT_Face face,
FT_ULong tag,
FT_Long offset,
FT_Byte* buffer,
FT_ULong* length )
{
FT_Error error;
FT_Stream stream;
TT_Table table;
FT_ULong size;
if ( tag != 0 )
{
/* look for tag in font directory */
table = tt_face_lookup_table( face, tag );
if ( !table )
{
error = SFNT_Err_Table_Missing;
goto Exit;
}
offset += table->Offset;
size = table->Length;
}
else
/* tag == 0 -- the user wants to access the font file directly */
size = face->root.stream->size;
if ( length && *length == 0 )
{
*length = size;
return SFNT_Err_Ok;
}
if ( length )
size = *length;
stream = face->root.stream;
/* the `if' is syntactic sugar for picky compilers */
if ( FT_STREAM_READ_AT( offset, buffer, size ) )
goto Exit;
Exit:
return error;
}
tt_face_goto_table( TT_Face face,
FT_ULong tag,
FT_Stream stream,
FT_ULong* length )
{
TT_Table table;
FT_Error error;
table = tt_face_lookup_table( face, tag );
if ( table )
{
if ( length )
*length = table->Length;
if ( FT_STREAM_SEEK( table->Offset ) )
goto Exit;
}
else
error = SFNT_Err_Table_Missing;
Exit:
return error;
}
sfnt_load_face(FT_Stream stream,
TT_Face face,
FT_Int face_index,
FT_Int num_params,
FT_Parameter * params)
{
FT_Error error;
#ifdef TT_CONFIG_OPTION_POSTSCRIPT_NAMES
FT_Error psnames_error;
#endif
FT_Bool has_outline;
FT_Bool is_apple_sbit;
FT_Bool ignore_preferred_family = FALSE;
FT_Bool ignore_preferred_subfamily = FALSE;
SFNT_Service sfnt = (SFNT_Service)face->sfnt;
FT_UNUSED(face_index);
/* Check parameters */
{
FT_Int i;
for (i = 0; i < num_params; i++)
{
if (params[i].tag == FT_PARAM_TAG_IGNORE_PREFERRED_FAMILY)
ignore_preferred_family = TRUE;
else if (params[i].tag == FT_PARAM_TAG_IGNORE_PREFERRED_SUBFAMILY)
ignore_preferred_subfamily = TRUE;
}
}
/* Load tables */
/* We now support two SFNT-based bitmapped font formats. They */
/* are recognized easily as they do not include a `glyf' */
/* table. */
/* */
/* The first format comes from Apple, and uses a table named */
/* `bhed' instead of `head' to store the font header (using */
/* the same format). It also doesn't include horizontal and */
/* vertical metrics tables (i.e. `hhea' and `vhea' tables are */
/* missing). */
/* */
/* The other format comes from Microsoft, and is used with */
/* WinCE/PocketPC. It looks like a standard TTF, except that */
/* it doesn't contain outlines. */
/* */
FT_TRACE2(("sfnt_load_face: %08p\n\n", face));
/* do we have outlines in there? */
#ifdef FT_CONFIG_OPTION_INCREMENTAL
has_outline = FT_BOOL(face->root.internal->incremental_interface != 0 ||
tt_face_lookup_table(face, TTAG_glyf) != 0 ||
tt_face_lookup_table(face, TTAG_CFF) != 0);
#else
has_outline = FT_BOOL(tt_face_lookup_table(face, TTAG_glyf) != 0 ||
tt_face_lookup_table(face, TTAG_CFF) != 0);
#endif
is_apple_sbit = 0;
/* if this font doesn't contain outlines, we try to load */
/* a `bhed' table */
if (!has_outline && sfnt->load_bhed)
{
LOAD_(bhed);
is_apple_sbit = FT_BOOL(!error);
}
/* load the font header (`head' table) if this isn't an Apple */
/* sbit font file */
if (!is_apple_sbit)
{
LOAD_(head);
if (error)
goto Exit;
}
if (face->header.Units_Per_EM == 0)
{
error = SFNT_Err_Invalid_Table;
goto Exit;
}
/* the following tables are often not present in embedded TrueType */
/* fonts within PDF documents, so don't check for them. */
LOAD_(maxp);
LOAD_(cmap);
/* the following tables are optional in PCL fonts -- */
/* don't check for errors */
LOAD_(name);
LOAD_(post);
#ifdef TT_CONFIG_OPTION_POSTSCRIPT_NAMES
psnames_error = error;
#endif
/* do not load the metrics headers and tables if this is an Apple */
/* sbit font file */
if (!is_apple_sbit)
{
/* load the `hhea' and `hmtx' tables */
LOADM_(hhea, 0);
if (!error)
{
LOADM_(hmtx, 0);
if (error == SFNT_Err_Table_Missing)
{
error = SFNT_Err_Hmtx_Table_Missing;
#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;
}
#endif
}
}
else if (error == SFNT_Err_Table_Missing)
{
/* No `hhea' table necessary for SFNT Mac fonts. */
if (face->format_tag == TTAG_true)
{
FT_TRACE2(("This is an SFNT Mac font.\n"));
has_outline = 0;
error = SFNT_Err_Ok;
}
else
{
error = SFNT_Err_Horiz_Header_Missing;
#ifdef FT_CONFIG_OPTION_INCREMENTAL
/* If this is an incrementally loaded font and there are */
/* overriding metrics, tolerate a missing `hhea' 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;
}
#endif
}
}
if (error)
goto Exit;
/* try to load the `vhea' and `vmtx' tables */
LOADM_(hhea, 1);
if (!error)
{
LOADM_(hmtx, 1);
if (!error)
face->vertical_info = 1;
}
if (error && error != SFNT_Err_Table_Missing)
goto Exit;
LOAD_(os2);
if (error)
{
if (error != SFNT_Err_Table_Missing)
goto Exit;
face->os2.version = 0xFFFFU;
}
}
/* the optional tables */
/* embedded bitmap support */
if (sfnt->load_eblc)
{
LOAD_(eblc);
if (error)
{
/* a font which contains neither bitmaps nor outlines is */
/* still valid (although rather useless in most cases); */
/* however, you can find such stripped fonts in PDFs */
if (error == SFNT_Err_Table_Missing)
error = SFNT_Err_Ok;
else
goto Exit;
}
}
LOAD_(pclt);
if (error)
{
if (error != SFNT_Err_Table_Missing)
goto Exit;
face->pclt.Version = 0;
}
/* consider the kerning and gasp tables as optional */
LOAD_(gasp);
LOAD_(kern);
face->root.num_glyphs = face->max_profile.numGlyphs;
/* Bit 8 of the `fsSelection' field in the `OS/2' table denotes */
/* a WWS-only font face. `WWS' stands for `weight', width', and */
/* `slope', a term used by Microsoft's Windows Presentation */
/* Foundation (WPF). This flag has been introduced in version */
/* 1.5 of the OpenType specification (May 2008). */
face->root.family_name = NULL;
face->root.style_name = NULL;
if (face->os2.version != 0xFFFFU && face->os2.fsSelection & 256)
{
if (!ignore_preferred_family)
GET_NAME(PREFERRED_FAMILY, &face->root.family_name);
if (!face->root.family_name)
GET_NAME(FONT_FAMILY, &face->root.family_name);
if (!ignore_preferred_subfamily)
GET_NAME(PREFERRED_SUBFAMILY, &face->root.style_name);
if (!face->root.style_name)
GET_NAME(FONT_SUBFAMILY, &face->root.style_name);
}
else
{
GET_NAME(WWS_FAMILY, &face->root.family_name);
if (!face->root.family_name && !ignore_preferred_family)
GET_NAME(PREFERRED_FAMILY, &face->root.family_name);
if (!face->root.family_name)
GET_NAME(FONT_FAMILY, &face->root.family_name);
GET_NAME(WWS_SUBFAMILY, &face->root.style_name);
if (!face->root.style_name && !ignore_preferred_subfamily)
GET_NAME(PREFERRED_SUBFAMILY, &face->root.style_name);
if (!face->root.style_name)
GET_NAME(FONT_SUBFAMILY, &face->root.style_name);
}
/* now set up root fields */
{
FT_Face root = &face->root;
FT_Long flags = root->face_flags;
/*********************************************************************/
/* */
/* Compute face flags. */
/* */
if (has_outline == TRUE)
flags |= FT_FACE_FLAG_SCALABLE; /* scalable outlines */
/* The sfnt driver only supports bitmap fonts natively, thus we */
/* don't set FT_FACE_FLAG_HINTER. */
flags |= FT_FACE_FLAG_SFNT | /* SFNT file format */
FT_FACE_FLAG_HORIZONTAL; /* horizontal data */
#ifdef TT_CONFIG_OPTION_POSTSCRIPT_NAMES
if (psnames_error == SFNT_Err_Ok &&
face->postscript.FormatType != 0x00030000L)
flags |= FT_FACE_FLAG_GLYPH_NAMES;
#endif
/* fixed width font? */
if (face->postscript.isFixedPitch)
flags |= FT_FACE_FLAG_FIXED_WIDTH;
/* vertical information? */
if (face->vertical_info)
flags |= FT_FACE_FLAG_VERTICAL;
/* kerning available ? */
if (TT_FACE_HAS_KERNING(face))
flags |= FT_FACE_FLAG_KERNING;
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
/* Don't bother to load the tables unless somebody asks for them. */
/* No need to do work which will (probably) not be used. */
if (tt_face_lookup_table(face, TTAG_glyf) != 0 &&
tt_face_lookup_table(face, TTAG_fvar) != 0 &&
tt_face_lookup_table(face, TTAG_gvar) != 0)
flags |= FT_FACE_FLAG_MULTIPLE_MASTERS;
#endif
root->face_flags = flags;
/*********************************************************************/
/* */
/* Compute style flags. */
/* */
flags = 0;
if (has_outline == TRUE && face->os2.version != 0xFFFFU)
{
/* We have an OS/2 table; use the `fsSelection' field. Bit 9 */
/* indicates an oblique font face. This flag has been */
/* introduced in version 1.5 of the OpenType specification. */
if (face->os2.fsSelection & 512) /* bit 9 */
flags |= FT_STYLE_FLAG_ITALIC;
else if (face->os2.fsSelection & 1) /* bit 0 */
flags |= FT_STYLE_FLAG_ITALIC;
if (face->os2.fsSelection & 32) /* bit 5 */
flags |= FT_STYLE_FLAG_BOLD;
}
else
{
/* this is an old Mac font, use the header field */
if (face->header.Mac_Style & 1)
flags |= FT_STYLE_FLAG_BOLD;
if (face->header.Mac_Style & 2)
flags |= FT_STYLE_FLAG_ITALIC;
}
root->style_flags = flags;
/*********************************************************************/
/* */
/* Polish the charmaps. */
/* */
/* Try to set the charmap encoding according to the platform & */
/* encoding ID of each charmap. */
/* */
tt_face_build_cmaps(face); /* ignore errors */
/* set the encoding fields */
{
FT_Int m;
for (m = 0; m < root->num_charmaps; m++)
{
FT_CharMap charmap = root->charmaps[m];
charmap->encoding = sfnt_find_encoding(charmap->platform_id,
charmap->encoding_id);
#if 0
if (root->charmap == NULL &&
charmap->encoding == FT_ENCODING_UNICODE)
{
/* set 'root->charmap' to the first Unicode encoding we find */
root->charmap = charmap;
}
#endif
}
}
#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
/*
* Now allocate the root array of FT_Bitmap_Size records and
* populate them. Unfortunately, it isn't possible to indicate bit
* depths in the FT_Bitmap_Size record. This is a design error.
*/
{
FT_UInt i, count;
#ifndef FT_CONFIG_OPTION_OLD_INTERNALS
count = face->sbit_num_strikes;
#else
count = (FT_UInt)face->num_sbit_strikes;
#endif
if (count > 0)
{
FT_Memory memory = face->root.stream->memory;
FT_UShort em_size = face->header.Units_Per_EM;
FT_Short avgwidth = face->os2.xAvgCharWidth;
FT_Size_Metrics metrics;
if (em_size == 0 || face->os2.version == 0xFFFFU)
{
avgwidth = 0;
em_size = 1;
}
if (FT_NEW_ARRAY(root->available_sizes, count))
goto Exit;
for (i = 0; i < count; i++)
{
FT_Bitmap_Size *bsize = root->available_sizes + i;
error = sfnt->load_strike_metrics(face, i, &metrics);
if (error)
goto Exit;
bsize->height = (FT_Short)(metrics.height >> 6);
bsize->width = (FT_Short)(
(avgwidth * metrics.x_ppem + em_size / 2) / em_size);
bsize->x_ppem = metrics.x_ppem << 6;
bsize->y_ppem = metrics.y_ppem << 6;
/* assume 72dpi */
bsize->size = metrics.y_ppem << 6;
}
root->face_flags |= FT_FACE_FLAG_FIXED_SIZES;
root->num_fixed_sizes = (FT_Int)count;
}
}
#endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
/* a font with no bitmaps and no outlines is scalable; */
/* it has only empty glyphs then */
if (!FT_HAS_FIXED_SIZES(root) && !FT_IS_SCALABLE(root))
root->face_flags |= FT_FACE_FLAG_SCALABLE;
/*********************************************************************/
/* */
/* Set up metrics. */
/* */
if (FT_IS_SCALABLE(root))
{
/* XXX What about if outline header is missing */
/* (e.g. sfnt wrapped bitmap)? */
root->bbox.xMin = face->header.xMin;
root->bbox.yMin = face->header.yMin;
root->bbox.xMax = face->header.xMax;
root->bbox.yMax = face->header.yMax;
root->units_per_EM = face->header.Units_Per_EM;
/* XXX: Computing the ascender/descender/height is very different */
/* from what the specification tells you. Apparently, we */
/* must be careful because */
/* */
/* - not all fonts have an OS/2 table; in this case, we take */
/* the values in the horizontal header. However, these */
/* values very often are not reliable. */
/* */
/* - otherwise, the correct typographic values are in the */
/* sTypoAscender, sTypoDescender & sTypoLineGap fields. */
/* */
/* However, certain fonts have these fields set to 0. */
/* Rather, they have usWinAscent & usWinDescent correctly */
/* set (but with different values). */
/* */
/* As an example, Arial Narrow is implemented through four */
/* files ARIALN.TTF, ARIALNI.TTF, ARIALNB.TTF & ARIALNBI.TTF */
/* */
/* Strangely, all fonts have the same values in their */
/* sTypoXXX fields, except ARIALNB which sets them to 0. */
/* */
/* On the other hand, they all have different */
/* usWinAscent/Descent values -- as a conclusion, the OS/2 */
/* table cannot be used to compute the text height reliably! */
/* */
/* The ascender/descender/height are computed from the OS/2 table */
/* when found. Otherwise, they're taken from the horizontal */
/* header. */
/* */
root->ascender = face->horizontal.Ascender;
root->descender = face->horizontal.Descender;
root->height = (FT_Short)(root->ascender - root->descender +
face->horizontal.Line_Gap);
#if 0
/* if the line_gap is 0, we add an extra 15% to the text height -- */
/* this computation is based on various versions of Times New Roman */
if (face->horizontal.Line_Gap == 0)
root->height = (FT_Short)((root->height * 115 + 50) / 100);
#endif /* 0 */
#if 0
/* some fonts have the OS/2 "sTypoAscender", "sTypoDescender" & */
/* "sTypoLineGap" fields set to 0, like ARIALNB.TTF */
if (face->os2.version != 0xFFFFU && root->ascender)
{
FT_Int height;
root->ascender = face->os2.sTypoAscender;
root->descender = -face->os2.sTypoDescender;
height = root->ascender + root->descender + face->os2.sTypoLineGap;
if (height > root->height)
root->height = height;
}
#endif /* 0 */
root->max_advance_width = face->horizontal.advance_Width_Max;
root->max_advance_height = (FT_Short)(face->vertical_info
? face->vertical.advance_Height_Max
: root->height);
/* See http://www.microsoft.com/OpenType/OTSpec/post.htm -- */
/* Adjust underline position from top edge to centre of */
/* stroke to convert TrueType meaning to FreeType meaning. */
root->underline_position = face->postscript.underlinePosition -
face->postscript.underlineThickness / 2;
root->underline_thickness = face->postscript.underlineThickness;
}
}
sfnt_load_face( FT_Stream stream,
TT_Face face,
FT_Int face_index,
FT_Int num_params,
FT_Parameter* params )
{
FT_Error error, psnames_error;
FT_Bool has_outline;
FT_Bool is_apple_sbit;
SFNT_Service sfnt = (SFNT_Service)face->sfnt;
FT_UNUSED( face_index );
FT_UNUSED( num_params );
FT_UNUSED( params );
/* Load tables */
/* We now support two SFNT-based bitmapped font formats. They */
/* are recognized easily as they do not include a `glyf' */
/* table. */
/* */
/* The first format comes from Apple, and uses a table named */
/* `bhed' instead of `head' to store the font header (using */
/* the same format). It also doesn't include horizontal and */
/* vertical metrics tables (i.e. `hhea' and `vhea' tables are */
/* missing). */
/* */
/* The other format comes from Microsoft, and is used with */
/* WinCE/PocketPC. It looks like a standard TTF, except that */
/* it doesn't contain outlines. */
/* */
/* do we have outlines in there? */
#ifdef FT_CONFIG_OPTION_INCREMENTAL
has_outline = FT_BOOL( face->root.internal->incremental_interface != 0 ||
tt_face_lookup_table( face, TTAG_glyf ) != 0 ||
tt_face_lookup_table( face, TTAG_CFF ) != 0 );
#else
has_outline = FT_BOOL( tt_face_lookup_table( face, TTAG_glyf ) != 0 ||
tt_face_lookup_table( face, TTAG_CFF ) != 0 );
#endif
is_apple_sbit = 0;
#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
/* if this font doesn't contain outlines, we try to load */
/* a `bhed' table */
if ( !has_outline )
is_apple_sbit = FT_BOOL( !LOAD_( bitmap_header ) );
#endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
/* load the font header (`head' table) if this isn't an Apple */
/* sbit font file */
if ( !is_apple_sbit && LOAD_( header ) )
goto Exit;
/* the following tables are often not present in embedded TrueType */
/* fonts within PDF documents, so don't check for them. */
(void)LOAD_( max_profile );
(void)LOAD_( charmaps );
/* the following tables are optional in PCL fonts -- */
/* don't check for errors */
(void)LOAD_( names );
psnames_error = LOAD_( psnames );
/* do not load the metrics headers and tables if this is an Apple */
/* sbit font file */
if ( !is_apple_sbit )
{
/* load the `hhea' and `hmtx' tables at once */
error = sfnt->load_metrics( face, stream, 0 );
if ( error )
goto Exit;
/* try to load the `vhea' and `vmtx' tables at once */
error = sfnt->load_metrics( face, stream, 1 );
if ( error )
goto Exit;
if ( LOAD_( os2 ) )
goto Exit;
}
/* the optional tables */
#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
/* embedded bitmap support. */
if ( sfnt->load_sbits && LOAD_( sbits ) )
{
/* return an error if this font file has no outlines */
if ( error == SFNT_Err_Table_Missing && has_outline )
error = SFNT_Err_Ok;
else
goto Exit;
}
#endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
if ( LOAD_( hdmx ) ||
LOAD_( pclt ) )
goto Exit;
/* consider the kerning and gasp tables as optional */
(void)LOAD_( gasp );
(void)LOAD_( kerning );
error = SFNT_Err_Ok;
face->root.family_name = tt_face_get_name( face,
TT_NAME_ID_PREFERRED_FAMILY );
if ( !face->root.family_name )
face->root.family_name = tt_face_get_name( face,
TT_NAME_ID_FONT_FAMILY );
face->root.style_name = tt_face_get_name( face,
TT_NAME_ID_PREFERRED_SUBFAMILY );
if ( !face->root.style_name )
face->root.style_name = tt_face_get_name( face,
TT_NAME_ID_FONT_SUBFAMILY );
/* now set up root fields */
{
FT_Face root = &face->root;
FT_Int32 flags = root->face_flags;
/*********************************************************************/
/* */
/* Compute face flags. */
/* */
if ( has_outline == TRUE )
flags |= FT_FACE_FLAG_SCALABLE; /* scalable outlines */
flags |= FT_FACE_FLAG_SFNT | /* SFNT file format */
FT_FACE_FLAG_HORIZONTAL; /* horizontal data */
#ifdef TT_CONFIG_OPTION_POSTSCRIPT_NAMES
if ( psnames_error == SFNT_Err_Ok &&
face->postscript.FormatType != 0x00030000L )
flags |= FT_FACE_FLAG_GLYPH_NAMES;
#endif
/* fixed width font? */
if ( face->postscript.isFixedPitch )
flags |= FT_FACE_FLAG_FIXED_WIDTH;
/* vertical information? */
if ( face->vertical_info )
flags |= FT_FACE_FLAG_VERTICAL;
#if 0
/* kerning available ? */
if ( TT_FACE_HAS_KERNING( face ) )
flags |= FT_FACE_FLAG_KERNING;
#endif
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
/* Don't bother to load the tables unless somebody asks for them. */
/* No need to do work which will (probably) not be used. */
if ( tt_face_lookup_table( face, TTAG_glyf ) != 0 &&
tt_face_lookup_table( face, TTAG_fvar ) != 0 &&
tt_face_lookup_table( face, TTAG_gvar ) != 0 )
flags |= FT_FACE_FLAG_MULTIPLE_MASTERS;
#endif
root->face_flags = flags;
/*********************************************************************/
/* */
/* Compute style flags. */
/* */
flags = 0;
if ( has_outline == TRUE && face->os2.version != 0xFFFFU )
{
/* we have an OS/2 table; use the `fsSelection' field */
if ( face->os2.fsSelection & 1 )
flags |= FT_STYLE_FLAG_ITALIC;
if ( face->os2.fsSelection & 32 )
flags |= FT_STYLE_FLAG_BOLD;
}
else
{
/* this is an old Mac font, use the header field */
if ( face->header.Mac_Style & 1 )
flags |= FT_STYLE_FLAG_BOLD;
if ( face->header.Mac_Style & 2 )
flags |= FT_STYLE_FLAG_ITALIC;
}
root->style_flags = flags;
/*********************************************************************/
/* */
/* Polish the charmaps. */
/* */
/* Try to set the charmap encoding according to the platform & */
/* encoding ID of each charmap. */
/* */
tt_face_build_cmaps( face ); /* ignore errors */
/* set the encoding fields */
{
FT_Int m;
for ( m = 0; m < root->num_charmaps; m++ )
{
FT_CharMap charmap = root->charmaps[m];
charmap->encoding = sfnt_find_encoding( charmap->platform_id,
charmap->encoding_id );
#if 0
if ( root->charmap == NULL &&
charmap->encoding == FT_ENCODING_UNICODE )
{
/* set 'root->charmap' to the first Unicode encoding we find */
root->charmap = charmap;
}
#endif
}
}
/*********************************************************************/
/* */
/* Set up metrics. */
/* */
if ( has_outline == TRUE )
{
/* XXX What about if outline header is missing */
/* (e.g. sfnt wrapped bitmap)? */
root->bbox.xMin = face->header.xMin;
root->bbox.yMin = face->header.yMin;
root->bbox.xMax = face->header.xMax;
root->bbox.yMax = face->header.yMax;
root->units_per_EM = face->header.Units_Per_EM;
/* XXX: Computing the ascender/descender/height is very different */
/* from what the specification tells you. Apparently, we */
/* must be careful because */
/* */
/* - not all fonts have an OS/2 table; in this case, we take */
/* the values in the horizontal header. However, these */
/* values very often are not reliable. */
/* */
/* - otherwise, the correct typographic values are in the */
/* sTypoAscender, sTypoDescender & sTypoLineGap fields. */
/* */
/* However, certains fonts have these fields set to 0. */
/* Rather, they have usWinAscent & usWinDescent correctly */
/* set (but with different values). */
/* */
/* As an example, Arial Narrow is implemented through four */
/* files ARIALN.TTF, ARIALNI.TTF, ARIALNB.TTF & ARIALNBI.TTF */
/* */
/* Strangely, all fonts have the same values in their */
/* sTypoXXX fields, except ARIALNB which sets them to 0. */
/* */
/* On the other hand, they all have different */
/* usWinAscent/Descent values -- as a conclusion, the OS/2 */
/* table cannot be used to compute the text height reliably! */
/* */
/* The ascender/descender/height are computed from the OS/2 table */
/* when found. Otherwise, they're taken from the horizontal */
/* header. */
/* */
root->ascender = face->horizontal.Ascender;
root->descender = face->horizontal.Descender;
root->height = (FT_Short)( root->ascender - root->descender +
face->horizontal.Line_Gap );
#if 0
/* if the line_gap is 0, we add an extra 15% to the text height -- */
/* this computation is based on various versions of Times New Roman */
if ( face->horizontal.Line_Gap == 0 )
root->height = (FT_Short)( ( root->height * 115 + 50 ) / 100 );
#endif
#if 0
/* some fonts have the OS/2 "sTypoAscender", "sTypoDescender" & */
/* "sTypoLineGap" fields set to 0, like ARIALNB.TTF */
if ( face->os2.version != 0xFFFFU && root->ascender )
{
FT_Int height;
root->ascender = face->os2.sTypoAscender;
root->descender = -face->os2.sTypoDescender;
height = root->ascender + root->descender + face->os2.sTypoLineGap;
if ( height > root->height )
root->height = height;
}
#endif /* 0 */
root->max_advance_width = face->horizontal.advance_Width_Max;
root->max_advance_height = (FT_Short)( face->vertical_info
? face->vertical.advance_Height_Max
: root->height );
root->underline_position = face->postscript.underlinePosition;
root->underline_thickness = face->postscript.underlineThickness;
/* root->max_points -- already set up */
/* root->max_contours -- already set up */
}
}
Exit:
return error;
}
