ttgload.c
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ttgload.c
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	/***************************************************************************/
	/* */
	/* ttgload.c */
	/* */
	/* TrueType Glyph Loader (body). */
	/* */
	/* Copyright 1996-2011 */
	/* 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_CALC_H
	#include FT_INTERNAL_STREAM_H
	#include FT_INTERNAL_SFNT_H
	#include FT_TRUETYPE_TAGS_H
	#include FT_OUTLINE_H

	#include "ttgload.h"
	#include "ttpload.h"

	#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
	#include "ttgxvar.h"
	#endif

	#include "tterrors.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_ttgload


	/*************************************************************************/
	/* */
	/* Composite glyph flags. */
	/* */
	#define ARGS_ARE_WORDS 0x0001
	#define ARGS_ARE_XY_VALUES 0x0002
	#define ROUND_XY_TO_GRID 0x0004
	#define WE_HAVE_A_SCALE 0x0008
	/* reserved 0x0010 */
	#define MORE_COMPONENTS 0x0020
	#define WE_HAVE_AN_XY_SCALE 0x0040
	#define WE_HAVE_A_2X2 0x0080
	#define WE_HAVE_INSTR 0x0100
	#define USE_MY_METRICS 0x0200
	#define OVERLAP_COMPOUND 0x0400
	#define SCALED_COMPONENT_OFFSET 0x0800
	#define UNSCALED_COMPONENT_OFFSET 0x1000


	/*************************************************************************/
	/* */
	/* Return the horizontal metrics in font units for a given glyph. */
	/* */
	FT_LOCAL_DEF( void )
	TT_Get_HMetrics( TT_Face face,
	FT_UInt idx,
	FT_Short* lsb,
	FT_UShort* aw )
	{
	( (SFNT_Service)face->sfnt )->get_metrics( face, 0, idx, lsb, aw );

	FT_TRACE5(( " advance width (font units): %d\n", *aw ));
	FT_TRACE5(( " left side bearing (font units): %d\n", *lsb ));
	}


	/*************************************************************************/
	/* */
	/* Return the vertical metrics in font units for a given glyph. */
	/* Greg Hitchcock from Microsoft told us that if there were no `vmtx' */
	/* table, typoAscender/Descender from the `OS/2' table would be used */
	/* instead, and if there were no `OS/2' table, use ascender/descender */
	/* from the `hhea' table. But that is not what Microsoft's rasterizer */
	/* apparently does: It uses the ppem value as the advance height, and */
	/* sets the top side bearing to be zero. */
	/* */
	FT_LOCAL_DEF( void )
	TT_Get_VMetrics( TT_Face face,
	FT_UInt idx,
	FT_Short* tsb,
	FT_UShort* ah )
	{
	if ( face->vertical_info )
	( (SFNT_Service)face->sfnt )->get_metrics( face, 1, idx, tsb, ah );

	#if 1 /* Empirically determined, at variance with what MS said */

	else
	{
	*tsb = 0;
	*ah = face->root.units_per_EM;
	}

	#else /* This is what MS said to do. It isn't what they do, however. */

	else if ( face->os2.version != 0xFFFFU )
	{
	*tsb = face->os2.sTypoAscender;
	*ah = face->os2.sTypoAscender - face->os2.sTypoDescender;
	}
	else
	{
	*tsb = face->horizontal.Ascender;
	*ah = face->horizontal.Ascender - face->horizontal.Descender;
	}

	#endif

	FT_TRACE5(( " advance height (font units): %d\n", *ah ));
	FT_TRACE5(( " top side bearing (font units): %d\n", *tsb ));
	}


	static void
	tt_get_metrics( TT_Loader loader,
	FT_UInt glyph_index )
	{
	TT_Face face = (TT_Face)loader->face;

	FT_Short left_bearing = 0, top_bearing = 0;
	FT_UShort advance_width = 0, advance_height = 0;


	TT_Get_HMetrics( face, glyph_index,
	&left_bearing,
	&advance_width );
	TT_Get_VMetrics( face, glyph_index,
	&top_bearing,
	&advance_height );

	loader->left_bearing = left_bearing;
	loader->advance = advance_width;
	loader->top_bearing = top_bearing;
	loader->vadvance = advance_height;

	if ( !loader->linear_def )
	{
	loader->linear_def = 1;
	loader->linear = advance_width;
	}
	}


	#ifdef FT_CONFIG_OPTION_INCREMENTAL

	static void
	tt_get_metrics_incr_overrides( TT_Loader loader,
	FT_UInt glyph_index )
	{
	TT_Face face = (TT_Face)loader->face;

	FT_Short left_bearing = 0, top_bearing = 0;
	FT_UShort advance_width = 0, advance_height = 0;


	/* If this is an incrementally loaded font check whether there are */
	/* overriding metrics for this glyph. */
	if ( face->root.internal->incremental_interface &&
	face->root.internal->incremental_interface->funcs->get_glyph_metrics )
	{
	FT_Incremental_MetricsRec metrics;
	FT_Error error;


	metrics.bearing_x = loader->left_bearing;
	metrics.bearing_y = 0;
	metrics.advance = loader->advance;
	metrics.advance_v = 0;

	error = face->root.internal->incremental_interface->funcs->get_glyph_metrics(
	face->root.internal->incremental_interface->object,
	glyph_index, FALSE, &metrics );
	if ( error )
	goto Exit;

	left_bearing = (FT_Short)metrics.bearing_x;
	advance_width = (FT_UShort)metrics.advance;

	#if 0

	/* GWW: Do I do the same for vertical metrics? */
	metrics.bearing_x = 0;
	metrics.bearing_y = loader->top_bearing;
	metrics.advance = loader->vadvance;

	error = face->root.internal->incremental_interface->funcs->get_glyph_metrics(
	face->root.internal->incremental_interface->object,
	glyph_index, TRUE, &metrics );
	if ( error )
	goto Exit;

	top_bearing = (FT_Short)metrics.bearing_y;
	advance_height = (FT_UShort)metrics.advance;

	#endif /* 0 */

	loader->left_bearing = left_bearing;
	loader->advance = advance_width;
	loader->top_bearing = top_bearing;
	loader->vadvance = advance_height;

	if ( !loader->linear_def )
	{
	loader->linear_def = 1;
	loader->linear = advance_width;
	}
	}

	Exit:
	return;
	}

	#endif /* FT_CONFIG_OPTION_INCREMENTAL */


	/*************************************************************************/
	/* */
	/* Translates an array of coordinates. */
	/* */
	static void
	translate_array( FT_UInt n,
	FT_Vector* coords,
	FT_Pos delta_x,
	FT_Pos delta_y )
	{
	FT_UInt k;


	if ( delta_x )
	for ( k = 0; k < n; k++ )
	coords[k].x += delta_x;

	if ( delta_y )
	for ( k = 0; k < n; k++ )
	coords[k].y += delta_y;
	}


	#undef IS_HINTED
	#define IS_HINTED( flags ) ( ( flags & FT_LOAD_NO_HINTING ) == 0 )


	/*************************************************************************/
	/* */
	/* The following functions are used by default with TrueType fonts. */
	/* However, they can be replaced by alternatives if we need to support */
	/* TrueType-compressed formats (like MicroType) in the future. */
	/* */
	/*************************************************************************/

	FT_CALLBACK_DEF( FT_Error )
	TT_Access_Glyph_Frame( TT_Loader loader,
	FT_UInt glyph_index,
	FT_ULong offset,
	FT_UInt byte_count )
	{
	FT_Error error;
	FT_Stream stream = loader->stream;

	/* for non-debug mode */
	FT_UNUSED( glyph_index );


	FT_TRACE4(( "Glyph %ld\n", glyph_index ));

	/* the following line sets the `error' variable through macros! */
	if ( FT_STREAM_SEEK( offset ) \|\| FT_FRAME_ENTER( byte_count ) )
	return error;

	loader->cursor = stream->cursor;
	loader->limit = stream->limit;

	return TT_Err_Ok;
	}


	FT_CALLBACK_DEF( void )
	TT_Forget_Glyph_Frame( TT_Loader loader )
	{
	FT_Stream stream = loader->stream;


	FT_FRAME_EXIT();
	}


	FT_CALLBACK_DEF( FT_Error )
	TT_Load_Glyph_Header( TT_Loader loader )
	{
	FT_Byte* p = loader->cursor;
	FT_Byte* limit = loader->limit;


	if ( p + 10 > limit )
	return TT_Err_Invalid_Outline;

	loader->n_contours = FT_NEXT_SHORT( p );

	loader->bbox.xMin = FT_NEXT_SHORT( p );
	loader->bbox.yMin = FT_NEXT_SHORT( p );
	loader->bbox.xMax = FT_NEXT_SHORT( p );
	loader->bbox.yMax = FT_NEXT_SHORT( p );

	FT_TRACE5(( " # of contours: %d\n", loader->n_contours ));
	FT_TRACE5(( " xMin: %4d xMax: %4d\n", loader->bbox.xMin,
	loader->bbox.xMax ));
	FT_TRACE5(( " yMin: %4d yMax: %4d\n", loader->bbox.yMin,
	loader->bbox.yMax ));
	loader->cursor = p;

	return TT_Err_Ok;
	}


	FT_CALLBACK_DEF( FT_Error )
	TT_Load_Simple_Glyph( TT_Loader load )
	{
	FT_Error error;
	FT_Byte* p = load->cursor;
	FT_Byte* limit = load->limit;
	FT_GlyphLoader gloader = load->gloader;
	FT_Int n_contours = load->n_contours;
	FT_Outline* outline;
	TT_Face face = (TT_Face)load->face;
	FT_UShort n_ins;
	FT_Int n_points;

	FT_Byte flag, flag_limit;
	FT_Byte c, count;
	FT_Vector vec, vec_limit;
	FT_Pos x;
	FT_Short cont, cont_limit, prev_cont;
	FT_Int xy_size = 0;


	/* check that we can add the contours to the glyph */
	error = FT_GLYPHLOADER_CHECK_POINTS( gloader, 0, n_contours );
	if ( error )
	goto Fail;

	/* reading the contours' endpoints & number of points */
	cont = gloader->current.outline.contours;
	cont_limit = cont + n_contours;

	/* check space for contours array + instructions count */
	if ( n_contours >= 0xFFF \|\| p + ( n_contours + 1 ) * 2 > limit )
	goto Invalid_Outline;

	prev_cont = FT_NEXT_USHORT( p );

	if ( n_contours > 0 )
	cont[0] = prev_cont;

	for ( cont++; cont < cont_limit; cont++ )
	{
	cont[0] = FT_NEXT_USHORT( p );
	if ( cont[0] <= prev_cont )
	{
	/* unordered contours: this is invalid */
	error = TT_Err_Invalid_Table;
	goto Fail;
	}
	prev_cont = cont[0];
	}

	n_points = 0;
	if ( n_contours > 0 )
	{
	n_points = cont[-1] + 1;
	if ( n_points < 0 )
	goto Invalid_Outline;
	}

	/* note that we will add four phantom points later */
	error = FT_GLYPHLOADER_CHECK_POINTS( gloader, n_points + 4, 0 );
	if ( error )
	goto Fail;

	/* we'd better check the contours table right now */
	outline = &gloader->current.outline;

	for ( cont = outline->contours + 1; cont < cont_limit; cont++ )
	if ( cont[-1] >= cont[0] )
	goto Invalid_Outline;

	/* reading the bytecode instructions */
	load->glyph->control_len = 0;
	load->glyph->control_data = 0;

	if ( p + 2 > limit )
	goto Invalid_Outline;

	n_ins = FT_NEXT_USHORT( p );

	FT_TRACE5(( " Instructions size: %u\n", n_ins ));

	if ( n_ins > face->max_profile.maxSizeOfInstructions )
	{
	FT_TRACE0(( "TT_Load_Simple_Glyph: too many instructions (%d)\n",
	n_ins ));
	error = TT_Err_Too_Many_Hints;
	goto Fail;
	}

	if ( ( limit - p ) < n_ins )
	{
	FT_TRACE0(( "TT_Load_Simple_Glyph: instruction count mismatch\n" ));
	error = TT_Err_Too_Many_Hints;
	goto Fail;
	}

	#ifdef TT_USE_BYTECODE_INTERPRETER

	if ( IS_HINTED( load->load_flags ) )
	{
	load->glyph->control_len = n_ins;
	load->glyph->control_data = load->exec->glyphIns;

	FT_MEM_COPY( load->exec->glyphIns, p, (FT_Long)n_ins );
	}

	#endif /* TT_USE_BYTECODE_INTERPRETER */

	p += n_ins;

	/* reading the point tags */
	flag = (FT_Byte*)outline->tags;
	flag_limit = flag + n_points;

	FT_ASSERT( flag != NULL );

	while ( flag < flag_limit )
	{
	if ( p + 1 > limit )
	goto Invalid_Outline;

	*flag++ = c = FT_NEXT_BYTE( p );
	if ( c & 8 )
	{
	if ( p + 1 > limit )
	goto Invalid_Outline;

	count = FT_NEXT_BYTE( p );
	if ( flag + (FT_Int)count > flag_limit )
	goto Invalid_Outline;

	for ( ; count > 0; count-- )
	*flag++ = c;
	}
	}

	/* reading the X coordinates */

	vec = outline->points;
	vec_limit = vec + n_points;
	flag = (FT_Byte*)outline->tags;
	x = 0;

	if ( p + xy_size > limit )
	goto Invalid_Outline;

	for ( ; vec < vec_limit; vec++, flag++ )
	{
	FT_Pos y = 0;
	FT_Byte f = *flag;


	if ( f & 2 )
	{
	if ( p + 1 > limit )
	goto Invalid_Outline;

	y = (FT_Pos)FT_NEXT_BYTE( p );
	if ( ( f & 16 ) == 0 )
	y = -y;
	}
	else if ( ( f & 16 ) == 0 )
	{
	if ( p + 2 > limit )
	goto Invalid_Outline;

	y = (FT_Pos)FT_NEXT_SHORT( p );
	}

	x += y;
	vec->x = x;
	/* the cast is for stupid compilers */
	*flag = (FT_Byte)( f & ~( 2 \| 16 ) );
	}

	/* reading the Y coordinates */

	vec = gloader->current.outline.points;
	vec_limit = vec + n_points;
	flag = (FT_Byte*)outline->tags;
	x = 0;

	for ( ; vec < vec_limit; vec++, flag++ )
	{
	FT_Pos y = 0;
	FT_Byte f = *flag;


	if ( f & 4 )
	{
	if ( p + 1 > limit )
	goto Invalid_Outline;

	y = (FT_Pos)FT_NEXT_BYTE( p );
	if ( ( f & 32 ) == 0 )
	y = -y;
	}
	else if ( ( f & 32 ) == 0 )
	{
	if ( p + 2 > limit )
	goto Invalid_Outline;

	y = (FT_Pos)FT_NEXT_SHORT( p );
	}

	x += y;
	vec->y = x;
	/* the cast is for stupid compilers */
	*flag = (FT_Byte)( f & FT_CURVE_TAG_ON );
	}

	outline->n_points = (FT_UShort)n_points;
	outline->n_contours = (FT_Short) n_contours;

	load->cursor = p;

	Fail:
	return error;

	Invalid_Outline:
	error = TT_Err_Invalid_Outline;
	goto Fail;
	}


	FT_CALLBACK_DEF( FT_Error )
	TT_Load_Composite_Glyph( TT_Loader loader )
	{
	FT_Error error;
	FT_Byte* p = loader->cursor;
	FT_Byte* limit = loader->limit;
	FT_GlyphLoader gloader = loader->gloader;
	FT_SubGlyph subglyph;
	FT_UInt num_subglyphs;


	num_subglyphs = 0;

	do
	{
	FT_Fixed xx, xy, yy, yx;
	FT_UInt count;


	/* check that we can load a new subglyph */
	error = FT_GlyphLoader_CheckSubGlyphs( gloader, num_subglyphs + 1 );
	if ( error )
	goto Fail;

	/* check space */
	if ( p + 4 > limit )
	goto Invalid_Composite;

	subglyph = gloader->current.subglyphs + num_subglyphs;

	subglyph->arg1 = subglyph->arg2 = 0;

	subglyph->flags = FT_NEXT_USHORT( p );
	subglyph->index = FT_NEXT_USHORT( p );

	/* check space */
	count = 2;
	if ( subglyph->flags & ARGS_ARE_WORDS )
	count += 2;
	if ( subglyph->flags & WE_HAVE_A_SCALE )
	count += 2;
	else if ( subglyph->flags & WE_HAVE_AN_XY_SCALE )
	count += 4;
	else if ( subglyph->flags & WE_HAVE_A_2X2 )
	count += 8;

	if ( p + count > limit )
	goto Invalid_Composite;

	/* read arguments */
	if ( subglyph->flags & ARGS_ARE_WORDS )
	{
	subglyph->arg1 = FT_NEXT_SHORT( p );
	subglyph->arg2 = FT_NEXT_SHORT( p );
	}
	else
	{
	subglyph->arg1 = FT_NEXT_CHAR( p );
	subglyph->arg2 = FT_NEXT_CHAR( p );
	}

	/* read transform */
	xx = yy = 0x10000L;
	xy = yx = 0;

	if ( subglyph->flags & WE_HAVE_A_SCALE )
	{
	xx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
	yy = xx;
	}
	else if ( subglyph->flags & WE_HAVE_AN_XY_SCALE )
	{
	xx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
	yy = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
	}
	else if ( subglyph->flags & WE_HAVE_A_2X2 )
	{
	xx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
	yx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
	xy = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
	yy = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
	}

	subglyph->transform.xx = xx;
	subglyph->transform.xy = xy;
	subglyph->transform.yx = yx;
	subglyph->transform.yy = yy;

	num_subglyphs++;

	} while ( subglyph->flags & MORE_COMPONENTS );

	gloader->current.num_subglyphs = num_subglyphs;

	#ifdef TT_USE_BYTECODE_INTERPRETER

	{
	FT_Stream stream = loader->stream;


	/* we must undo the FT_FRAME_ENTER in order to point */
	/* to the composite instructions, if we find some. */
	/* We will process them later. */
	/* */
	loader->ins_pos = (FT_ULong)( FT_STREAM_POS() +
	p - limit );
	}

	#endif

	loader->cursor = p;

	Fail:
	return error;

	Invalid_Composite:
	error = TT_Err_Invalid_Composite;
	goto Fail;
	}


	FT_LOCAL_DEF( void )
	TT_Init_Glyph_Loading( TT_Face face )
	{
	face->access_glyph_frame = TT_Access_Glyph_Frame;
	face->read_glyph_header = TT_Load_Glyph_Header;
	face->read_simple_glyph = TT_Load_Simple_Glyph;
	face->read_composite_glyph = TT_Load_Composite_Glyph;
	face->forget_glyph_frame = TT_Forget_Glyph_Frame;
	}


	static void
	tt_prepare_zone( TT_GlyphZone zone,
	FT_GlyphLoad load,
	FT_UInt start_point,
	FT_UInt start_contour )
	{
	zone->n_points = (FT_UShort)( load->outline.n_points - start_point );
	zone->n_contours = (FT_Short) ( load->outline.n_contours -
	start_contour );
	zone->org = load->extra_points + start_point;
	zone->cur = load->outline.points + start_point;
	zone->orus = load->extra_points2 + start_point;
	zone->tags = (FT_Byte*)load->outline.tags + start_point;
	zone->contours = (FT_UShort*)load->outline.contours + start_contour;
	zone->first_point = (FT_UShort)start_point;
	}


	/*************************************************************************/
	/* */
	/* <Function> */
	/* TT_Hint_Glyph */
	/* */
	/* <Description> */
	/* Hint the glyph using the zone prepared by the caller. Note that */
	/* the zone is supposed to include four phantom points. */
	/* */
	static FT_Error
	TT_Hint_Glyph( TT_Loader loader,
	FT_Bool is_composite )
	{
	TT_GlyphZone zone = &loader->zone;
	FT_Pos origin;

	#ifdef TT_USE_BYTECODE_INTERPRETER
	FT_UInt n_ins;
	#else
	FT_UNUSED( is_composite );
	#endif


	#ifdef TT_USE_BYTECODE_INTERPRETER
	if ( loader->glyph->control_len > 0xFFFFL )
	{
	FT_TRACE1(( "TT_Hint_Glyph: too long instructions " ));
	FT_TRACE1(( "(0x%lx byte) is truncated\n",
	loader->glyph->control_len ));
	}
	n_ins = (FT_UInt)( loader->glyph->control_len );
	#endif

	origin = zone->cur[zone->n_points - 4].x;
	origin = FT_PIX_ROUND( origin ) - origin;
	if ( origin )
	translate_array( zone->n_points, zone->cur, origin, 0 );

	#ifdef TT_USE_BYTECODE_INTERPRETER
	/* save original point position in org */
	if ( n_ins > 0 )
	FT_ARRAY_COPY( zone->org, zone->cur, zone->n_points );

	/* Reset graphics state. */
	loader->exec->GS = ((TT_Size)loader->size)->GS;

	/* XXX: UNDOCUMENTED! Hinting instructions of a composite glyph */
	/* completely refer to the (already) hinted subglyphs. */
	if ( is_composite )
	{
	loader->exec->metrics.x_scale = 1 << 16;
	loader->exec->metrics.y_scale = 1 << 16;

	FT_ARRAY_COPY( zone->orus, zone->cur, zone->n_points );
	}
	else
	{
	loader->exec->metrics.x_scale =
	((TT_Size)loader->size)->metrics.x_scale;
	loader->exec->metrics.y_scale =
	((TT_Size)loader->size)->metrics.y_scale;
	}
	#endif

	/* round pp2 and pp4 */
	zone->cur[zone->n_points - 3].x =
	FT_PIX_ROUND( zone->cur[zone->n_points - 3].x );
	zone->cur[zone->n_points - 1].y =
	FT_PIX_ROUND( zone->cur[zone->n_points - 1].y );

	#ifdef TT_USE_BYTECODE_INTERPRETER

	if ( n_ins > 0 )
	{
	FT_Bool debug;
	FT_Error error;

	FT_GlyphLoader gloader = loader->gloader;
	FT_Outline current_outline = gloader->current.outline;


	error = TT_Set_CodeRange( loader->exec, tt_coderange_glyph,
	loader->exec->glyphIns, n_ins );
	if ( error )
	return error;

	loader->exec->is_composite = is_composite;
	loader->exec->pts = *zone;

	debug = FT_BOOL( !( loader->load_flags & FT_LOAD_NO_SCALE ) &&
	((TT_Size)loader->size)->debug );

	error = TT_Run_Context( loader->exec, debug );
	if ( error && loader->exec->pedantic_hinting )
	return error;

	/* store drop-out mode in bits 5-7; set bit 2 also as a marker */
	current_outline.tags[0] \|=
	( loader->exec->GS.scan_type << 5 ) \| FT_CURVE_TAG_HAS_SCANMODE;
	}

	#endif

	/* save glyph phantom points */
	if ( !loader->preserve_pps )
	{
	loader->pp1 = zone->cur[zone->n_points - 4];
	loader->pp2 = zone->cur[zone->n_points - 3];
	loader->pp3 = zone->cur[zone->n_points - 2];
	loader->pp4 = zone->cur[zone->n_points - 1];
	}

	return TT_Err_Ok;
	}


	/*************************************************************************/
	/* */
	/* <Function> */
	/* TT_Process_Simple_Glyph */
	/* */
	/* <Description> */
	/* Once a simple glyph has been loaded, it needs to be processed. */
	/* Usually, this means scaling and hinting through bytecode */
	/* interpretation. */
	/* */
	static FT_Error
	TT_Process_Simple_Glyph( TT_Loader loader )
	{
	FT_GlyphLoader gloader = loader->gloader;
	FT_Error error = TT_Err_Ok;
	FT_Outline* outline;
	FT_Int n_points;


	outline = &gloader->current.outline;
	n_points = outline->n_points;

	/* set phantom points */

	outline->points[n_points ] = loader->pp1;
	outline->points[n_points + 1] = loader->pp2;
	outline->points[n_points + 2] = loader->pp3;
	outline->points[n_points + 3] = loader->pp4;

	outline->tags[n_points ] = 0;
	outline->tags[n_points + 1] = 0;
	outline->tags[n_points + 2] = 0;
	outline->tags[n_points + 3] = 0;

	n_points += 4;

	#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT

	if ( ((TT_Face)loader->face)->doblend )
	{
	/* Deltas apply to the unscaled data. */
	FT_Vector* deltas;
	FT_Memory memory = loader->face->memory;
	FT_Int i;


	error = TT_Vary_Get_Glyph_Deltas( (TT_Face)(loader->face),
	loader->glyph_index,
	&deltas,
	n_points );
	if ( error )
	return error;

	for ( i = 0; i < n_points; ++i )
	{
	outline->points[i].x += deltas[i].x;
	outline->points[i].y += deltas[i].y;
	}

	FT_FREE( deltas );
	}

	#endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */

	if ( IS_HINTED( loader->load_flags ) )
	{
	tt_prepare_zone( &loader->zone, &gloader->current, 0, 0 );

	FT_ARRAY_COPY( loader->zone.orus, loader->zone.cur,
	loader->zone.n_points + 4 );
	}

	/* scale the glyph */
	if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
	{
	FT_Vector* vec = outline->points;
	FT_Vector* limit = outline->points + n_points;
	FT_Fixed x_scale = ((TT_Size)loader->size)->metrics.x_scale;
	FT_Fixed y_scale = ((TT_Size)loader->size)->metrics.y_scale;


	for ( ; vec < limit; vec++ )
	{
	vec->x = FT_MulFix( vec->x, x_scale );
	vec->y = FT_MulFix( vec->y, y_scale );
	}

	loader->pp1 = outline->points[n_points - 4];
	loader->pp2 = outline->points[n_points - 3];
	loader->pp3 = outline->points[n_points - 2];
	loader->pp4 = outline->points[n_points - 1];
	}

	if ( IS_HINTED( loader->load_flags ) )
	{
	loader->zone.n_points += 4;

	error = TT_Hint_Glyph( loader, 0 );
	}

	return error;
	}


	/*************************************************************************/
	/* */
	/* <Function> */
	/* TT_Process_Composite_Component */
	/* */
	/* <Description> */
	/* Once a composite component has been loaded, it needs to be */
	/* processed. Usually, this means transforming and translating. */
	/* */
	static FT_Error
	TT_Process_Composite_Component( TT_Loader loader,
	FT_SubGlyph subglyph,
	FT_UInt start_point,
	FT_UInt num_base_points )
	{
	FT_GlyphLoader gloader = loader->gloader;
	FT_Vector* base_vec = gloader->base.outline.points;
	FT_UInt num_points = gloader->base.outline.n_points;
	FT_Bool have_scale;
	FT_Pos x, y;


	have_scale = FT_BOOL( subglyph->flags & ( WE_HAVE_A_SCALE \|
	WE_HAVE_AN_XY_SCALE \|
	WE_HAVE_A_2X2 ) );

	/* perform the transform required for this subglyph */
	if ( have_scale )
	{
	FT_UInt i;


	for ( i = num_base_points; i < num_points; i++ )
	FT_Vector_Transform( base_vec + i, &subglyph->transform );
	}

	/* get offset */
	if ( !( subglyph->flags & ARGS_ARE_XY_VALUES ) )
	{
	FT_UInt k = subglyph->arg1;
	FT_UInt l = subglyph->arg2;
	FT_Vector* p1;
	FT_Vector* p2;


	/* match l-th point of the newly loaded component to the k-th point */
	/* of the previously loaded components. */

	/* change to the point numbers used by our outline */
	k += start_point;
	l += num_base_points;
	if ( k >= num_base_points \|\|
	l >= num_points )
	return TT_Err_Invalid_Composite;

	p1 = gloader->base.outline.points + k;
	p2 = gloader->base.outline.points + l;

	x = p1->x - p2->x;
	y = p1->y - p2->y;
	}
	else
	{
	x = subglyph->arg1;
	y = subglyph->arg2;

	if ( !x && !y )
	return TT_Err_Ok;

	/* Use a default value dependent on */
	/* TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED. This is useful for old TT */
	/* fonts which don't set the xxx_COMPONENT_OFFSET bit. */

	if ( have_scale &&
	#ifdef TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED
	!( subglyph->flags & UNSCALED_COMPONENT_OFFSET ) )
	#else
	( subglyph->flags & SCALED_COMPONENT_OFFSET ) )
	#endif
	{

	#if 0

	/*************************************************************************/
	/* */
	/* This algorithm is what Apple documents. But it doesn't work. */
	/* */
	int a = subglyph->transform.xx > 0 ? subglyph->transform.xx
	: -subglyph->transform.xx;
	int b = subglyph->transform.yx > 0 ? subglyph->transform.yx
	: -subglyph->transform.yx;
	int c = subglyph->transform.xy > 0 ? subglyph->transform.xy
	: -subglyph->transform.xy;
	int d = subglyph->transform.yy > 0 ? subglyph->transform.yy
	: -subglyph->transform.yy;
	int m = a > b ? a : b;
	int n = c > d ? c : d;


	if ( a - b <= 33 && a - b >= -33 )
	m *= 2;
	if ( c - d <= 33 && c - d >= -33 )
	n *= 2;
	x = FT_MulFix( x, m );
	y = FT_MulFix( y, n );

	#else /* 0 */

	/*************************************************************************/
	/* */
	/* This algorithm is a guess and works much better than the above. */
	/* */
	FT_Fixed mac_xscale = FT_SqrtFixed(
	(FT_Int32)FT_MulFix( subglyph->transform.xx,
	subglyph->transform.xx ) +
	(FT_Int32)FT_MulFix( subglyph->transform.xy,
	subglyph->transform.xy ) );
	FT_Fixed mac_yscale = FT_SqrtFixed(
	(FT_Int32)FT_MulFix( subglyph->transform.yy,
	subglyph->transform.yy ) +
	(FT_Int32)FT_MulFix( subglyph->transform.yx,
	subglyph->transform.yx ) );


	x = FT_MulFix( x, mac_xscale );
	y = FT_MulFix( y, mac_yscale );

	#endif /* 0 */

	}

	if ( !( loader->load_flags & FT_LOAD_NO_SCALE ) )
	{
	FT_Fixed x_scale = ((TT_Size)loader->size)->metrics.x_scale;
	FT_Fixed y_scale = ((TT_Size)loader->size)->metrics.y_scale;


	x = FT_MulFix( x, x_scale );
	y = FT_MulFix( y, y_scale );

	if ( subglyph->flags & ROUND_XY_TO_GRID )
	{
	x = FT_PIX_ROUND( x );
	y = FT_PIX_ROUND( y );
	}
	}
	}

	if ( x \|\| y )
	translate_array( num_points - num_base_points,
	base_vec + num_base_points,
	x, y );

	return TT_Err_Ok;
	}


	/*************************************************************************/
	/* */
	/* <Function> */
	/* TT_Process_Composite_Glyph */
	/* */
	/* <Description> */
	/* This is slightly different from TT_Process_Simple_Glyph, in that */
	/* its sole purpose is to hint the glyph. Thus this function is */
	/* only available when bytecode interpreter is enabled. */
	/* */
	static FT_Error
	TT_Process_Composite_Glyph( TT_Loader loader,
	FT_UInt start_point,
	FT_UInt start_contour )
	{
	FT_Error error;
	FT_Outline* outline;
	FT_UInt i;


	outline = &loader->gloader->base.outline;

	/* make room for phantom points */
	error = FT_GLYPHLOADER_CHECK_POINTS( loader->gloader,
	outline->n_points + 4,
	0 );
	if ( error )
	return error;

	outline->points[outline->n_points ] = loader->pp1;
	outline->points[outline->n_points + 1] = loader->pp2;
	outline->points[outline->n_points + 2] = loader->pp3;
	outline->points[outline->n_points + 3] = loader->pp4;

	outline->tags[outline->n_points ] = 0;
	outline->tags[outline->n_points + 1] = 0;
	outline->tags[outline->n_points + 2] = 0;
	outline->tags[outline->n_points + 3] = 0;

	#ifdef TT_USE_BYTECODE_INTERPRETER

	{
	FT_Stream stream = loader->stream;
	FT_UShort n_ins, max_ins;
	FT_ULong tmp;


	/* TT_Load_Composite_Glyph only gives us the offset of instructions */
	/* so we read them here */
	if ( FT_STREAM_SEEK( loader->ins_pos ) \|\|
	FT_READ_USHORT( n_ins ) )
	return error;

	FT_TRACE5(( " Instructions size = %d\n", n_ins ));

	/* check it */
	max_ins = ((TT_Face)loader->face)->max_profile.maxSizeOfInstructions;
	if ( n_ins > max_ins )
	{
	/* acroread ignores this field, so we only do a rough safety check */
	if ( (FT_Int)n_ins > loader->byte_len )
	{
	FT_TRACE1(( "TT_Process_Composite_Glyph: "
	"too many instructions (%d) for glyph with length %d\n",
	n_ins, loader->byte_len ));
	return TT_Err_Too_Many_Hints;
	}

	tmp = loader->exec->glyphSize;
	error = Update_Max( loader->exec->memory,
	&tmp,
	sizeof ( FT_Byte ),
	(void*)&loader->exec->glyphIns,
	n_ins );
	loader->exec->glyphSize = (FT_UShort)tmp;
	if ( error )
	return error;
	}
	else if ( n_ins == 0 )
	return TT_Err_Ok;

	if ( FT_STREAM_READ( loader->exec->glyphIns, n_ins ) )
	return error;

	loader->glyph->control_data = loader->exec->glyphIns;
	loader->glyph->control_len = n_ins;
	}

	#endif

	tt_prepare_zone( &loader->zone, &loader->gloader->base,
	start_point, start_contour );

	/* Some points are likely touched during execution of */
	/* instructions on components. So let's untouch them. */
	for ( i = start_point; i < loader->zone.n_points; i++ )
	loader->zone.tags[i] &= ~FT_CURVE_TAG_TOUCH_BOTH;

	loader->zone.n_points += 4;

	return TT_Hint_Glyph( loader, 1 );
	}


	/* Calculate the four phantom points. */
	/* The first two stand for horizontal origin and advance. */
	/* The last two stand for vertical origin and advance. */
	#define TT_LOADER_SET_PP( loader ) \
	do { \
	(loader)->pp1.x = (loader)->bbox.xMin - (loader)->left_bearing; \
	(loader)->pp1.y = 0; \
	(loader)->pp2.x = (loader)->pp1.x + (loader)->advance; \
	(loader)->pp2.y = 0; \
	(loader)->pp3.x = 0; \
	(loader)->pp3.y = (loader)->top_bearing + (loader)->bbox.yMax; \
	(loader)->pp4.x = 0; \
	(loader)->pp4.y = (loader)->pp3.y - (loader)->vadvance; \
	} while ( 0 )


	/*************************************************************************/
	/* */
	/* <Function> */
	/* load_truetype_glyph */
	/* */
	/* <Description> */
	/* Loads a given truetype glyph. Handles composites and uses a */
	/* TT_Loader object. */
	/* */
	static FT_Error
	load_truetype_glyph( TT_Loader loader,
	FT_UInt glyph_index,
	FT_UInt recurse_count,
	FT_Bool header_only )
	{
	FT_Error error = TT_Err_Ok;
	FT_Fixed x_scale, y_scale;
	FT_ULong offset;
	TT_Face face = (TT_Face)loader->face;
	FT_GlyphLoader gloader = loader->gloader;
	FT_Bool opened_frame = 0;

	#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
	FT_Vector* deltas = NULL;
	#endif

	#ifdef FT_CONFIG_OPTION_INCREMENTAL
	FT_StreamRec inc_stream;
	FT_Data glyph_data;
	FT_Bool glyph_data_loaded = 0;
	#endif


	/* some fonts have an incorrect value of `maxComponentDepth', */
	/* thus we allow depth 1 to catch the majority of them */
	if ( recurse_count > 1 &&
	recurse_count > face->max_profile.maxComponentDepth )
	{
	error = TT_Err_Invalid_Composite;
	goto Exit;
	}

	/* check glyph index */
	if ( glyph_index >= (FT_UInt)face->root.num_glyphs )
	{
	error = TT_Err_Invalid_Glyph_Index;
	goto Exit;
	}

	loader->glyph_index = glyph_index;

	if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
	{
	x_scale = ((TT_Size)loader->size)->metrics.x_scale;
	y_scale = ((TT_Size)loader->size)->metrics.y_scale;
	}
	else
	{
	x_scale = 0x10000L;
	y_scale = 0x10000L;
	}

	tt_get_metrics( loader, glyph_index );

	/* Set `offset' to the start of the glyph relative to the start of */
	/* the `glyf' table, and `byte_len' to the length of the glyph in */
	/* bytes. */

	#ifdef FT_CONFIG_OPTION_INCREMENTAL

	/* If we are loading glyph data via the incremental interface, set */
	/* the loader stream to a memory stream reading the data returned */
	/* by the interface. */
	if ( face->root.internal->incremental_interface )
	{
	error = face->root.internal->incremental_interface->funcs->get_glyph_data(
	face->root.internal->incremental_interface->object,
	glyph_index, &glyph_data );
	if ( error )
	goto Exit;

	glyph_data_loaded = 1;
	offset = 0;
	loader->byte_len = glyph_data.length;

	FT_MEM_ZERO( &inc_stream, sizeof ( inc_stream ) );
	FT_Stream_OpenMemory( &inc_stream,
	glyph_data.pointer, glyph_data.length );

	loader->stream = &inc_stream;
	}
	else

	#endif /* FT_CONFIG_OPTION_INCREMENTAL */

	offset = tt_face_get_location( face, glyph_index,
	(FT_UInt*)&loader->byte_len );

	if ( loader->byte_len > 0 )
	{
	#ifdef FT_CONFIG_OPTION_INCREMENTAL
	/* for the incremental interface, `glyf_offset' is always zero */
	if ( !loader->glyf_offset &&
	!face->root.internal->incremental_interface )
	#else
	if ( !loader->glyf_offset )
	#endif /* FT_CONFIG_OPTION_INCREMENTAL */
	{
	FT_TRACE2(( "no `glyf' table but non-zero `loca' entry\n" ));
	error = TT_Err_Invalid_Table;
	goto Exit;
	}

	error = face->access_glyph_frame( loader, glyph_index,
	loader->glyf_offset + offset,
	loader->byte_len );
	if ( error )
	goto Exit;

	opened_frame = 1;

	/* read glyph header first */
	error = face->read_glyph_header( loader );
	if ( error \|\| header_only )
	goto Exit;
	}

	if ( loader->byte_len == 0 \|\| loader->n_contours == 0 )
	{
	loader->bbox.xMin = 0;
	loader->bbox.xMax = 0;
	loader->bbox.yMin = 0;
	loader->bbox.yMax = 0;

	if ( header_only )
	goto Exit;

	/* must initialize points before (possibly) overriding */
	/* glyph metrics from the incremental interface */
	TT_LOADER_SET_PP( loader );

	#ifdef FT_CONFIG_OPTION_INCREMENTAL
	tt_get_metrics_incr_overrides( loader, glyph_index );
	#endif

	#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT

	if ( ((TT_Face)(loader->face))->doblend )
	{
	/* this must be done before scaling */
	FT_Memory memory = loader->face->memory;


	error = TT_Vary_Get_Glyph_Deltas( (TT_Face)(loader->face),
	glyph_index, &deltas, 4 );
	if ( error )
	goto Exit;

	loader->pp1.x += deltas[0].x; loader->pp1.y += deltas[0].y;
	loader->pp2.x += deltas[1].x; loader->pp2.y += deltas[1].y;
	loader->pp3.x += deltas[2].x; loader->pp3.y += deltas[2].y;
	loader->pp4.x += deltas[3].x; loader->pp4.y += deltas[3].y;

	FT_FREE( deltas );
	}

	#endif

	if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
	{
	loader->pp1.x = FT_MulFix( loader->pp1.x, x_scale );
	loader->pp2.x = FT_MulFix( loader->pp2.x, x_scale );
	loader->pp3.y = FT_MulFix( loader->pp3.y, y_scale );
	loader->pp4.y = FT_MulFix( loader->pp4.y, y_scale );
	}

	error = TT_Err_Ok;
	goto Exit;
	}

	/* must initialize points before (possibly) overriding */
	/* glyph metrics from the incremental interface */
	TT_LOADER_SET_PP( loader );

	#ifdef FT_CONFIG_OPTION_INCREMENTAL
	tt_get_metrics_incr_overrides( loader, glyph_index );
	#endif

	/***********************************************************************/
	/***********************************************************************/
	/***********************************************************************/

	/* if it is a simple glyph, load it */

	if ( loader->n_contours > 0 )
	{
	error = face->read_simple_glyph( loader );
	if ( error )
	goto Exit;

	/* all data have been read */
	face->forget_glyph_frame( loader );
	opened_frame = 0;

	error = TT_Process_Simple_Glyph( loader );
	if ( error )
	goto Exit;

	FT_GlyphLoader_Add( gloader );
	}

	/***********************************************************************/
	/***********************************************************************/
	/***********************************************************************/

	/* otherwise, load a composite! */
	else if ( loader->n_contours == -1 )
	{
	FT_UInt start_point;
	FT_UInt start_contour;
	FT_ULong ins_pos; /* position of composite instructions, if any */


	start_point = gloader->base.outline.n_points;
	start_contour = gloader->base.outline.n_contours;

	/* for each subglyph, read composite header */
	error = face->read_composite_glyph( loader );
	if ( error )
	goto Exit;

	/* store the offset of instructions */
	ins_pos = loader->ins_pos;

	/* all data we need are read */
	face->forget_glyph_frame( loader );
	opened_frame = 0;

	#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT

	if ( face->doblend )
	{
	FT_Int i, limit;
	FT_SubGlyph subglyph;
	FT_Memory memory = face->root.memory;


	/* this provides additional offsets */
	/* for each component's translation */

	if ( ( error = TT_Vary_Get_Glyph_Deltas(
	face,
	glyph_index,
	&deltas,
	gloader->current.num_subglyphs + 4 )) != 0 )
	goto Exit;

	subglyph = gloader->current.subglyphs + gloader->base.num_subglyphs;
	limit = gloader->current.num_subglyphs;

	for ( i = 0; i < limit; ++i, ++subglyph )
	{
	if ( subglyph->flags & ARGS_ARE_XY_VALUES )
	{
	/* XXX: overflow check for subglyph->{arg1,arg2}. */
	/* deltas[i].{x,y} must be within signed 16-bit, */
	/* but the restriction of summed delta is not clear */
	subglyph->arg1 += (FT_Int16)deltas[i].x;
	subglyph->arg2 += (FT_Int16)deltas[i].y;
	}
	}

	loader->pp1.x += deltas[i + 0].x; loader->pp1.y += deltas[i + 0].y;
	loader->pp2.x += deltas[i + 1].x; loader->pp2.y += deltas[i + 1].y;
	loader->pp3.x += deltas[i + 2].x; loader->pp3.y += deltas[i + 2].y;
	loader->pp4.x += deltas[i + 3].x; loader->pp4.y += deltas[i + 3].y;

	FT_FREE( deltas );
	}

	#endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */

	if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
	{
	loader->pp1.x = FT_MulFix( loader->pp1.x, x_scale );
	loader->pp2.x = FT_MulFix( loader->pp2.x, x_scale );
	loader->pp3.y = FT_MulFix( loader->pp3.y, y_scale );
	loader->pp4.y = FT_MulFix( loader->pp4.y, y_scale );
	}

	/* if the flag FT_LOAD_NO_RECURSE is set, we return the subglyph */
	/* `as is' in the glyph slot (the client application will be */
	/* responsible for interpreting these data)... */
	if ( loader->load_flags & FT_LOAD_NO_RECURSE )
	{
	FT_GlyphLoader_Add( gloader );
	loader->glyph->format = FT_GLYPH_FORMAT_COMPOSITE;

	goto Exit;
	}

	/*********************************************************************/
	/*********************************************************************/
	/*********************************************************************/

	{
	FT_UInt n, num_base_points;
	FT_SubGlyph subglyph = 0;

	FT_UInt num_points = start_point;
	FT_UInt num_subglyphs = gloader->current.num_subglyphs;
	FT_UInt num_base_subgs = gloader->base.num_subglyphs;

	FT_Stream old_stream = loader->stream;
	FT_Int old_byte_len = loader->byte_len;


	FT_GlyphLoader_Add( gloader );

	/* read each subglyph independently */
	for ( n = 0; n < num_subglyphs; n++ )
	{
	FT_Vector pp[4];


	/* Each time we call load_truetype_glyph in this loop, the */
	/* value of `gloader.base.subglyphs' can change due to table */
	/* reallocations. We thus need to recompute the subglyph */
	/* pointer on each iteration. */
	subglyph = gloader->base.subglyphs + num_base_subgs + n;

	pp[0] = loader->pp1;
	pp[1] = loader->pp2;
	pp[2] = loader->pp3;
	pp[3] = loader->pp4;

	num_base_points = gloader->base.outline.n_points;

	error = load_truetype_glyph( loader, subglyph->index,
	recurse_count + 1, FALSE );
	if ( error )
	goto Exit;

	/* restore subglyph pointer */
	subglyph = gloader->base.subglyphs + num_base_subgs + n;

	if ( !( subglyph->flags & USE_MY_METRICS ) )
	{
	loader->pp1 = pp[0];
	loader->pp2 = pp[1];
	loader->pp3 = pp[2];
	loader->pp4 = pp[3];
	}

	num_points = gloader->base.outline.n_points;

	if ( num_points == num_base_points )
	continue;

	/* gloader->base.outline consists of three parts: */
	/* 0 -(1)-> start_point -(2)-> num_base_points -(3)-> n_points. */
	/* */
	/* (1): exists from the beginning */
	/* (2): components that have been loaded so far */
	/* (3): the newly loaded component */
	TT_Process_Composite_Component( loader, subglyph, start_point,
	num_base_points );
	}

	loader->stream = old_stream;
	loader->byte_len = old_byte_len;

	/* process the glyph */
	loader->ins_pos = ins_pos;
	if ( IS_HINTED( loader->load_flags ) &&

	#ifdef TT_USE_BYTECODE_INTERPRETER

	subglyph->flags & WE_HAVE_INSTR &&

	#endif

	num_points > start_point )
	TT_Process_Composite_Glyph( loader, start_point, start_contour );

	}
	}
	else
	{
	/* invalid composite count (negative but not -1) */
	error = TT_Err_Invalid_Outline;
	goto Exit;
	}

	/***********************************************************************/
	/***********************************************************************/
	/***********************************************************************/

	Exit:

	if ( opened_frame )
	face->forget_glyph_frame( loader );

	#ifdef FT_CONFIG_OPTION_INCREMENTAL

	if ( glyph_data_loaded )
	face->root.internal->incremental_interface->funcs->free_glyph_data(
	face->root.internal->incremental_interface->object,
	&glyph_data );

	#endif

	return error;
	}


	static FT_Error
	compute_glyph_metrics( TT_Loader loader,
	FT_UInt glyph_index )
	{
	FT_BBox bbox;
	TT_Face face = (TT_Face)loader->face;
	FT_Fixed y_scale;
	TT_GlyphSlot glyph = loader->glyph;
	TT_Size size = (TT_Size)loader->size;


	y_scale = 0x10000L;
	if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
	y_scale = size->root.metrics.y_scale;

	if ( glyph->format != FT_GLYPH_FORMAT_COMPOSITE )
	FT_Outline_Get_CBox( &glyph->outline, &bbox );
	else
	bbox = loader->bbox;

	/* get the device-independent horizontal advance; it is scaled later */
	/* by the base layer. */
	glyph->linearHoriAdvance = loader->linear;

	glyph->metrics.horiBearingX = bbox.xMin;
	glyph->metrics.horiBearingY = bbox.yMax;
	glyph->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;

	/* adjust advance width to the value contained in the hdmx table */
	if ( !face->postscript.isFixedPitch &&
	IS_HINTED( loader->load_flags ) )
	{
	FT_Byte* widthp;


	widthp = tt_face_get_device_metrics( face,
	size->root.metrics.x_ppem,
	glyph_index );

	if ( widthp )
	glyph->metrics.horiAdvance = *widthp << 6;
	}

	/* set glyph dimensions */
	glyph->metrics.width = bbox.xMax - bbox.xMin;
	glyph->metrics.height = bbox.yMax - bbox.yMin;

	/* Now take care of vertical metrics. In the case where there is */
	/* no vertical information within the font (relatively common), */
	/* create some metrics manually */
	{
	FT_Pos top; /* scaled vertical top side bearing */
	FT_Pos advance; /* scaled vertical advance height */


	/* Get the unscaled top bearing and advance height. */
	if ( face->vertical_info &&
	face->vertical.number_Of_VMetrics > 0 )
	{
	top = (FT_Short)FT_DivFix( loader->pp3.y - bbox.yMax,
	y_scale );

	if ( loader->pp3.y <= loader->pp4.y )
	advance = 0;
	else
	advance = (FT_UShort)FT_DivFix( loader->pp3.y - loader->pp4.y,
	y_scale );
	}
	else
	{
	FT_Pos height;


	/* XXX Compute top side bearing and advance height in */
	/* Get_VMetrics instead of here. */

	/* NOTE: The OS/2 values are the only `portable' ones, */
	/* which is why we use them, if there is an OS/2 */
	/* table in the font. Otherwise, we use the */
	/* values defined in the horizontal header. */

	height = (FT_Short)FT_DivFix( bbox.yMax - bbox.yMin,
	y_scale );
	if ( face->os2.version != 0xFFFFU )
	advance = (FT_Pos)( face->os2.sTypoAscender -
	face->os2.sTypoDescender );
	else
	advance = (FT_Pos)( face->horizontal.Ascender -
	face->horizontal.Descender );

	top = ( advance - height ) / 2;
	}

	#ifdef FT_CONFIG_OPTION_INCREMENTAL
	{
	FT_Incremental_InterfaceRec* incr;
	FT_Incremental_MetricsRec metrics;
	FT_Error error;


	incr = face->root.internal->incremental_interface;

	/* If this is an incrementally loaded font see if there are */
	/* overriding metrics for this glyph. */
	if ( incr && incr->funcs->get_glyph_metrics )
	{
	metrics.bearing_x = 0;
	metrics.bearing_y = top;
	metrics.advance = advance;

	error = incr->funcs->get_glyph_metrics( incr->object,
	glyph_index,
	TRUE,
	&metrics );
	if ( error )
	return error;

	top = metrics.bearing_y;
	advance = metrics.advance;
	}
	}

	/* GWW: Do vertical metrics get loaded incrementally too? */

	#endif /* FT_CONFIG_OPTION_INCREMENTAL */

	glyph->linearVertAdvance = advance;

	/* scale the metrics */
	if ( !( loader->load_flags & FT_LOAD_NO_SCALE ) )
	{
	top = FT_MulFix( top, y_scale );
	advance = FT_MulFix( advance, y_scale );
	}

	/* XXX: for now, we have no better algorithm for the lsb, but it */
	/* should work fine. */
	/* */
	glyph->metrics.vertBearingX = glyph->metrics.horiBearingX -
	glyph->metrics.horiAdvance / 2;
	glyph->metrics.vertBearingY = top;
	glyph->metrics.vertAdvance = advance;
	}

	return 0;
	}


	#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS

	static FT_Error
	load_sbit_image( TT_Size size,
	TT_GlyphSlot glyph,
	FT_UInt glyph_index,
	FT_Int32 load_flags )
	{
	TT_Face face;
	SFNT_Service sfnt;
	FT_Stream stream;
	FT_Error error;
	TT_SBit_MetricsRec metrics;


	face = (TT_Face)glyph->face;
	sfnt = (SFNT_Service)face->sfnt;
	stream = face->root.stream;

	error = sfnt->load_sbit_image( face,
	size->strike_index,
	glyph_index,
	(FT_Int)load_flags,
	stream,
	&glyph->bitmap,
	&metrics );
	if ( !error )
	{
	glyph->outline.n_points = 0;
	glyph->outline.n_contours = 0;

	glyph->metrics.width = (FT_Pos)metrics.width << 6;
	glyph->metrics.height = (FT_Pos)metrics.height << 6;

	glyph->metrics.horiBearingX = (FT_Pos)metrics.horiBearingX << 6;
	glyph->metrics.horiBearingY = (FT_Pos)metrics.horiBearingY << 6;
	glyph->metrics.horiAdvance = (FT_Pos)metrics.horiAdvance << 6;

	glyph->metrics.vertBearingX = (FT_Pos)metrics.vertBearingX << 6;
	glyph->metrics.vertBearingY = (FT_Pos)metrics.vertBearingY << 6;
	glyph->metrics.vertAdvance = (FT_Pos)metrics.vertAdvance << 6;

	glyph->format = FT_GLYPH_FORMAT_BITMAP;

	if ( load_flags & FT_LOAD_VERTICAL_LAYOUT )
	{
	glyph->bitmap_left = metrics.vertBearingX;
	glyph->bitmap_top = metrics.vertBearingY;
	}
	else
	{
	glyph->bitmap_left = metrics.horiBearingX;
	glyph->bitmap_top = metrics.horiBearingY;
	}
	}

	return error;
	}

	#endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */


	static FT_Error
	tt_loader_init( TT_Loader loader,
	TT_Size size,
	TT_GlyphSlot glyph,
	FT_Int32 load_flags,
	FT_Bool glyf_table_only )
	{
	TT_Face face;
	FT_Stream stream;
	FT_Bool pedantic = FT_BOOL( load_flags & FT_LOAD_PEDANTIC );


	face = (TT_Face)glyph->face;
	stream = face->root.stream;

	FT_MEM_ZERO( loader, sizeof ( TT_LoaderRec ) );

	#ifdef TT_USE_BYTECODE_INTERPRETER

	/* load execution context */
	if ( IS_HINTED( load_flags ) && !glyf_table_only )
	{
	TT_ExecContext exec;
	FT_Bool grayscale;


	if ( !size->cvt_ready )
	{
	FT_Error error = tt_size_ready_bytecode( size, pedantic );


	if ( error )
	return error;
	}

	/* query new execution context */
	exec = size->debug ? size->context
	: ( (TT_Driver)FT_FACE_DRIVER( face ) )->context;
	if ( !exec )
	return TT_Err_Could_Not_Find_Context;

	grayscale =
	FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) != FT_RENDER_MODE_MONO );

	TT_Load_Context( exec, face, size );

	/* a change from mono to grayscale rendering (and vice versa) */
	/* requires a re-execution of the CVT program */
	if ( grayscale != exec->grayscale )
	{
	FT_UInt i;


	FT_TRACE4(( "tt_loader_init: grayscale change,"
	" re-executing `prep' table\n" ));

	exec->grayscale = grayscale;

	for ( i = 0; i < size->cvt_size; i++ )
	size->cvt[i] = FT_MulFix( face->cvt[i], size->ttmetrics.scale );
	tt_size_run_prep( size, pedantic );
	}

	/* see whether the cvt program has disabled hinting */
	if ( exec->GS.instruct_control & 1 )
	load_flags \|= FT_LOAD_NO_HINTING;

	/* load default graphics state -- if needed */
	if ( exec->GS.instruct_control & 2 )
	exec->GS = tt_default_graphics_state;

	exec->pedantic_hinting = FT_BOOL( load_flags & FT_LOAD_PEDANTIC );
	loader->exec = exec;
	loader->instructions = exec->glyphIns;
	}

	#endif /* TT_USE_BYTECODE_INTERPRETER */

	/* seek to the beginning of the glyph table -- for Type 42 fonts */
	/* the table might be accessed from a Postscript stream or something */
	/* else... */

	#ifdef FT_CONFIG_OPTION_INCREMENTAL

	if ( face->root.internal->incremental_interface )
	loader->glyf_offset = 0;
	else

	#endif

	{
	FT_Error error = face->goto_table( face, TTAG_glyf, stream, 0 );


	if ( error == TT_Err_Table_Missing )
	loader->glyf_offset = 0;
	else if ( error )
	{
	FT_ERROR(( "tt_loader_init: could not access glyph table\n" ));
	return error;
	}
	else
	loader->glyf_offset = FT_STREAM_POS();
	}

	/* get face's glyph loader */
	if ( !glyf_table_only )
	{
	FT_GlyphLoader gloader = glyph->internal->loader;


	FT_GlyphLoader_Rewind( gloader );
	loader->gloader = gloader;
	}

	loader->load_flags = load_flags;

	loader->face = (FT_Face)face;
	loader->size = (FT_Size)size;
	loader->glyph = (FT_GlyphSlot)glyph;
	loader->stream = stream;

	return TT_Err_Ok;
	}


	/*************************************************************************/
	/* */
	/* <Function> */
	/* TT_Load_Glyph */
	/* */
	/* <Description> */
	/* A function used to load a single glyph within a given glyph slot, */
	/* for a given size. */
	/* */
	/* <Input> */
	/* glyph :: A handle to a target slot object where the glyph */
	/* will be loaded. */
	/* */
	/* size :: A handle to the source face size at which the glyph */
	/* must be scaled/loaded. */
	/* */
	/* glyph_index :: The index of the glyph in the font file. */
	/* */
	/* load_flags :: A flag indicating what to load for this glyph. The */
	/* FT_LOAD_XXX constants can be used to control the */
	/* glyph loading process (e.g., whether the outline */
	/* should be scaled, whether to load bitmaps or not, */
	/* whether to hint the outline, etc). */
	/* */
	/* <Return> */
	/* FreeType error code. 0 means success. */
	/* */
	FT_LOCAL_DEF( FT_Error )
	TT_Load_Glyph( TT_Size size,
	TT_GlyphSlot glyph,
	FT_UInt glyph_index,
	FT_Int32 load_flags )
	{
	TT_Face face;
	FT_Error error;
	TT_LoaderRec loader;


	face = (TT_Face)glyph->face;
	error = TT_Err_Ok;

	#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS

	/* try to load embedded bitmap if any */
	/* */
	/* XXX: The convention should be emphasized in */
	/* the documents because it can be confusing. */
	if ( size->strike_index != 0xFFFFFFFFUL &&
	( load_flags & FT_LOAD_NO_BITMAP ) == 0 )
	{
	error = load_sbit_image( size, glyph, glyph_index, load_flags );
	if ( !error )
	{
	FT_Face root = &face->root;


	if ( FT_IS_SCALABLE( root ) )
	{
	/* for the bbox we need the header only */
	(void)tt_loader_init( &loader, size, glyph, load_flags, TRUE );
	(void)load_truetype_glyph( &loader, glyph_index, 0, TRUE );
	glyph->linearHoriAdvance = loader.linear;
	glyph->linearVertAdvance = loader.top_bearing + loader.bbox.yMax -
	loader.vadvance;
	}

	return TT_Err_Ok;
	}
	}

	#endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */

	/* if FT_LOAD_NO_SCALE is not set, `ttmetrics' must be valid */
	if ( !( load_flags & FT_LOAD_NO_SCALE ) && !size->ttmetrics.valid )
	return TT_Err_Invalid_Size_Handle;

	if ( load_flags & FT_LOAD_SBITS_ONLY )
	return TT_Err_Invalid_Argument;

	error = tt_loader_init( &loader, size, glyph, load_flags, FALSE );
	if ( error )
	return error;

	glyph->format = FT_GLYPH_FORMAT_OUTLINE;
	glyph->num_subglyphs = 0;
	glyph->outline.flags = 0;

	/* main loading loop */
	error = load_truetype_glyph( &loader, glyph_index, 0, FALSE );
	if ( !error )
	{
	if ( glyph->format == FT_GLYPH_FORMAT_COMPOSITE )
	{
	glyph->num_subglyphs = loader.gloader->base.num_subglyphs;
	glyph->subglyphs = loader.gloader->base.subglyphs;
	}
	else
	{
	glyph->outline = loader.gloader->base.outline;
	glyph->outline.flags &= ~FT_OUTLINE_SINGLE_PASS;

	/* Translate array so that (0,0) is the glyph's origin. Note */
	/* that this behaviour is independent on the value of bit 1 of */
	/* the `flags' field in the `head' table -- at least major */
	/* applications like Acroread indicate that. */
	if ( loader.pp1.x )
	FT_Outline_Translate( &glyph->outline, -loader.pp1.x, 0 );
	}

	#ifdef TT_USE_BYTECODE_INTERPRETER

	if ( IS_HINTED( load_flags ) )
	{
	if ( loader.exec->GS.scan_control )
	{
	/* convert scan conversion mode to FT_OUTLINE_XXX flags */
	switch ( loader.exec->GS.scan_type )
	{
	case 0: /* simple drop-outs including stubs */
	glyph->outline.flags \|= FT_OUTLINE_INCLUDE_STUBS;
	break;
	case 1: /* simple drop-outs excluding stubs */
	/* nothing; it's the default rendering mode */
	break;
	case 4: /* smart drop-outs including stubs */
	glyph->outline.flags \|= FT_OUTLINE_SMART_DROPOUTS \|
	FT_OUTLINE_INCLUDE_STUBS;
	break;
	case 5: /* smart drop-outs excluding stubs */
	glyph->outline.flags \|= FT_OUTLINE_SMART_DROPOUTS;
	break;

	default: /* no drop-out control */
	glyph->outline.flags \|= FT_OUTLINE_IGNORE_DROPOUTS;
	break;
	}
	}
	else
	glyph->outline.flags \|= FT_OUTLINE_IGNORE_DROPOUTS;
	}

	#endif /* TT_USE_BYTECODE_INTERPRETER */

	compute_glyph_metrics( &loader, glyph_index );
	}

	/* Set the `high precision' bit flag. */
	/* This is _critical_ to get correct output for monochrome */
	/* TrueType glyphs at all sizes using the bytecode interpreter. */
	/* */
	if ( !( load_flags & FT_LOAD_NO_SCALE ) &&
	size->root.metrics.y_ppem < 24 )
	glyph->outline.flags \|= FT_OUTLINE_HIGH_PRECISION;

	return error;
	}


	/* END */

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