ref: 71d289da3b6372e1d7c844060c44d3ba1cfefa04
dir: /src/sfnt/ttmtx.c/
/***************************************************************************/
/* */
/* ttmtx.c */
/* */
/* Load the metrics tables common to TTF and OTF fonts (body). */
/* */
/* Copyright 2006-2017 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
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
#include FT_SERVICE_METRICS_VARIATIONS_H
#endif
#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;
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
FT_Service_MetricsVariations var =
(FT_Service_MetricsVariations)face->var;
#endif
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;
}
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
if ( var )
{
FT_Face f = FT_FACE( face );
FT_Int a = (FT_Int)*aadvance;
FT_Int b = (FT_Int)*abearing;
if ( vertical )
{
if ( var->vadvance_adjust )
var->vadvance_adjust( f, gindex, &a );
if ( var->tsb_adjust )
var->tsb_adjust( f, gindex, &b );
}
else
{
if ( var->hadvance_adjust )
var->hadvance_adjust( f, gindex, &a );
if ( var->lsb_adjust )
var->lsb_adjust( f, gindex, &b );
}
*aadvance = (FT_UShort)a;
*abearing = (FT_Short)b;
}
#endif
}
/* END */