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freetype/src/truetype/ttgload.c
Ben Wagner 369d8be97f [truetype] Prevent glyph program state from persisting. 
`FDEF` instructions are specified as allowed only in 'prep' or
'fpgm'.  FreeType has attempted to prevent their use in the glyph
program, but they were still allowed in glyph programs if defined in
a function defined in 'prep' or 'fpgm' and called from the glyph
program.

Similarly, `IDEF` instructions are specified not to be able to
modify any existing instruction.  FreeType has attempted to prevent
their use in the glyph program, but they can still be used like
`FDEF`.

This change stores the initial bytecode range type and disallows the
use of `FDEF` and `IDEF` while running the glyph program.

Most other state is copied from the `TT_Size` into the execution
context.  However, it is possible for a glyph program to use `WS` to
write to the storage area or `WCVTP`, `WCVTF`, and `DELTAC[123]` to
write to the control value table.

Allowing any change to the global state from the glyph program is
problematic as the outlines of any given glyph may change based on
the order the glyphs are loaded or even how many times they are
loaded.  There exist fonts that write to the storage area or the
control value table in the glyph program, so their use should not be
an error.

Possible solutions to using these in the glyph program are

  * ignore the writes;
  * value-level copy on write, discard modified values when finished;
  * array-level copy on write, discard the copy when finished;
  * array-level copy up-front.

Ignoring the writes may break otherwise good uses.  A full copy
up-front was implemented, but was quite heavy as even well behaved
fonts required a full copy and the memory management that goes along
with it.  Value-level copy on write could use less memory but
requires a great deal more record keeping and complexity.  This
change implements array-level copy on write.  If any attempt is made
to write to the control value table or the storage area when the
initial bytecode range was in a glyph program, the relevant array
will be copied to a designated storage area and the copy used for
the rest of the glyph program's execution.

* src/truetype/ttinterp.h (TT_ExecContextRec): New fields
`iniRange`, `glyfCvtSize`, `glyfCvt`, `origCvt`, `glyfStoreSize`,
`glyfStorage`, and `origStorage`.

* src/truetype/ttinterp.c (Modify_CVT_Check): New function to handle
`exc->glyfCvt`.
(Write_CVT, Write_CVT_Stretched, Move_CVT, Move_CVT_Stretched): Use
it.
(Ins_WS): Handle `exc->glyfStorage`.
(Ins_FDEF, Ins_IDEF): Updated.
(TT_RunIns): Updated.
(TT_Done_Context): Free 'glyf' CVT working and storage area.
(TT_Load_Context): Fix/add casts.

* src/truetype/ttgload.c (TT_Load_Simple_Glyph): Fix cast.
2021-04-02 10:31:39 +02:00

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/****************************************************************************
*
* ttgload.c
*
* TrueType Glyph Loader (body).
*
* Copyright (C) 1996-2021 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 <freetype/internal/ftdebug.h>
#include FT_CONFIG_CONFIG_H
#include <freetype/internal/ftcalc.h>
#include <freetype/internal/ftstream.h>
#include <freetype/internal/sfnt.h>
#include <freetype/tttags.h>
#include <freetype/ftoutln.h>
#include <freetype/ftdriver.h>
#include <freetype/ftlist.h>
#include "ttgload.h"
#include "ttpload.h"
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
#include "ttgxvar.h"
#endif
#include "tterrors.h"
#include "ttsubpix.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 ttgload
/**************************************************************************
*
* Simple glyph flags.
*/
#define ON_CURVE_POINT 0x01 /* same value as FT_CURVE_TAG_ON */
#define X_SHORT_VECTOR 0x02
#define Y_SHORT_VECTOR 0x04
#define REPEAT_FLAG 0x08
#define X_POSITIVE 0x10 /* two meanings depending on X_SHORT_VECTOR */
#define SAME_X 0x10
#define Y_POSITIVE 0x20 /* two meanings depending on Y_SHORT_VECTOR */
#define SAME_Y 0x20
#define OVERLAP_SIMPLE 0x40 /* retained as FT_OUTLINE_OVERLAP */
/**************************************************************************
*
* 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 /* retained as FT_OUTLINE_OVERLAP */
#define SCALED_COMPONENT_OFFSET 0x0800
#define UNSCALED_COMPONENT_OFFSET 0x1000
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
#define IS_DEFAULT_INSTANCE( _face ) \
( !( FT_IS_NAMED_INSTANCE( _face ) || \
FT_IS_VARIATION( _face ) ) )
#else
#define IS_DEFAULT_INSTANCE( _face ) 1
#endif
/**************************************************************************
*
* 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.
* See function `tt_loader_set_pp' below for explanations.
*/
FT_LOCAL_DEF( void )
TT_Get_VMetrics( TT_Face face,
FT_UInt idx,
FT_Pos yMax,
FT_Short* tsb,
FT_UShort* ah )
{
if ( face->vertical_info )
( (SFNT_Service)face->sfnt )->get_metrics( face, 1, idx, tsb, ah );
else if ( face->os2.version != 0xFFFFU )
{
*tsb = (FT_Short)( face->os2.sTypoAscender - yMax );
*ah = (FT_UShort)FT_ABS( face->os2.sTypoAscender -
face->os2.sTypoDescender );
}
else
{
*tsb = (FT_Short)( face->horizontal.Ascender - yMax );
*ah = (FT_UShort)FT_ABS( face->horizontal.Ascender -
face->horizontal.Descender );
}
#ifdef FT_DEBUG_LEVEL_TRACE
if ( !face->vertical_info )
FT_TRACE5(( " [vertical metrics missing, computing values]\n" ));
#endif
FT_TRACE5(( " advance height (font units): %d\n", *ah ));
FT_TRACE5(( " top side bearing (font units): %d\n", *tsb ));
}
static FT_Error
tt_get_metrics( TT_Loader loader,
FT_UInt glyph_index )
{
TT_Face face = loader->face;
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
TT_Driver driver = (TT_Driver)FT_FACE_DRIVER( face );
#endif
FT_Error error;
FT_Stream stream = loader->stream;
FT_Short left_bearing = 0, top_bearing = 0;
FT_UShort advance_width = 0, advance_height = 0;
/* we must preserve the stream position */
/* (which gets altered by the metrics functions) */
FT_ULong pos = FT_STREAM_POS();
TT_Get_HMetrics( face, glyph_index,
&left_bearing,
&advance_width );
TT_Get_VMetrics( face, glyph_index,
loader->bbox.yMax,
&top_bearing,
&advance_height );
if ( FT_STREAM_SEEK( pos ) )
return error;
loader->left_bearing = left_bearing;
loader->advance = advance_width;
loader->top_bearing = top_bearing;
loader->vadvance = advance_height;
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 &&
loader->exec )
{
loader->exec->sph_tweak_flags = 0;
/* This may not be the right place for this, but it works... */
/* Note that we have to unconditionally load the tweaks since */
/* it is possible that glyphs individually switch ClearType's */
/* backward compatibility mode on and off. */
sph_set_tweaks( loader, glyph_index );
}
#endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */
#ifdef FT_CONFIG_OPTION_INCREMENTAL
/* With the incremental interface, these values are set by */
/* a call to `tt_get_metrics_incremental'. */
if ( face->root.internal->incremental_interface == NULL )
#endif
{
if ( !loader->linear_def )
{
loader->linear_def = 1;
loader->linear = advance_width;
}
}
return FT_Err_Ok;
}
#ifdef FT_CONFIG_OPTION_INCREMENTAL
static void
tt_get_metrics_incremental( TT_Loader loader,
FT_UInt glyph_index )
{
TT_Face 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 incr_metrics;
FT_Error error;
incr_metrics.bearing_x = loader->left_bearing;
incr_metrics.bearing_y = 0;
incr_metrics.advance = loader->advance;
incr_metrics.advance_v = 0;
error = face->root.internal->incremental_interface->funcs->get_glyph_metrics(
face->root.internal->incremental_interface->object,
glyph_index, FALSE, &incr_metrics );
if ( error )
goto Exit;
left_bearing = (FT_Short)incr_metrics.bearing_x;
advance_width = (FT_UShort)incr_metrics.advance;
#if 0
/* GWW: Do I do the same for vertical metrics? */
incr_metrics.bearing_x = 0;
incr_metrics.bearing_y = loader->top_bearing;
incr_metrics.advance = loader->vadvance;
error = face->root.internal->incremental_interface->funcs->get_glyph_metrics(
face->root.internal->incremental_interface->object,
glyph_index, TRUE, &incr_metrics );
if ( error )
goto Exit;
top_bearing = (FT_Short)incr_metrics.bearing_y;
advance_height = (FT_UShort)incr_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 */
/**************************************************************************
*
* 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;
FT_UNUSED( 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 FT_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 FT_THROW( 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: %4ld xMax: %4ld\n", loader->bbox.xMin,
loader->bbox.xMax ));
FT_TRACE5(( " yMin: %4ld yMax: %4ld\n", loader->bbox.yMin,
loader->bbox.yMax ));
loader->cursor = p;
return FT_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;
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, y;
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_SHORT( p );
if ( n_contours > 0 )
cont[0] = prev_cont;
if ( prev_cont < 0 )
goto Invalid_Outline;
for ( cont++; cont < cont_limit; cont++ )
{
cont[0] = FT_NEXT_SHORT( p );
if ( cont[0] <= prev_cont )
{
/* unordered contours: this is invalid */
goto Invalid_Outline;
}
prev_cont = cont[0];
}
n_points = 0;
if ( n_contours > 0 )
{
n_points = cont[-1] + 1;
if ( n_points < 0 )
goto Invalid_Outline;
}
FT_TRACE5(( " # of points: %d\n", n_points ));
/* note that we will add four phantom points later */
error = FT_GLYPHLOADER_CHECK_POINTS( gloader, n_points + 4, 0 );
if ( error )
goto Fail;
/* reading the bytecode instructions */
load->glyph->control_len = 0;
load->glyph->control_data = NULL;
if ( p + 2 > limit )
goto Invalid_Outline;
n_ins = FT_NEXT_USHORT( p );
FT_TRACE5(( " Instructions size: %u\n", n_ins ));
#ifdef TT_USE_BYTECODE_INTERPRETER
if ( IS_HINTED( load->load_flags ) )
{
FT_ULong tmp;
/* check instructions size */
if ( ( limit - p ) < n_ins )
{
FT_TRACE1(( "TT_Load_Simple_Glyph: instruction count mismatch\n" ));
error = FT_THROW( Too_Many_Hints );
goto Fail;
}
/* we don't trust `maxSizeOfInstructions' in the `maxp' table */
/* and thus update the bytecode array size by ourselves */
tmp = load->exec->glyphSize;
error = Update_Max( load->exec->memory,
&tmp,
sizeof ( FT_Byte ),
(void*)&load->exec->glyphIns,
n_ins );
load->exec->glyphSize = (FT_UInt)tmp;
if ( error )
return error;
load->glyph->control_len = n_ins;
load->glyph->control_data = load->exec->glyphIns;
if ( n_ins )
FT_MEM_COPY( load->exec->glyphIns, p, (FT_Long)n_ins );
}
#endif /* TT_USE_BYTECODE_INTERPRETER */
p += n_ins;
outline = &gloader->current.outline;
/* reading the point tags */
flag = (FT_Byte*)outline->tags;
flag_limit = flag + n_points;
FT_ASSERT( flag );
while ( flag < flag_limit )
{
if ( p + 1 > limit )
goto Invalid_Outline;
*flag++ = c = FT_NEXT_BYTE( p );
if ( c & REPEAT_FLAG )
{
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;
}
}
/* retain the overlap flag */
if ( n_points && outline->tags[0] & OVERLAP_SIMPLE )
gloader->base.outline.flags |= FT_OUTLINE_OVERLAP;
/* 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 delta = 0;
FT_Byte f = *flag;
if ( f & X_SHORT_VECTOR )
{
if ( p + 1 > limit )
goto Invalid_Outline;
delta = (FT_Pos)FT_NEXT_BYTE( p );
if ( !( f & X_POSITIVE ) )
delta = -delta;
}
else if ( !( f & SAME_X ) )
{
if ( p + 2 > limit )
goto Invalid_Outline;
delta = (FT_Pos)FT_NEXT_SHORT( p );
}
x += delta;
vec->x = x;
}
/* reading the Y coordinates */
vec = gloader->current.outline.points;
vec_limit = vec + n_points;
flag = (FT_Byte*)outline->tags;
y = 0;
for ( ; vec < vec_limit; vec++, flag++ )
{
FT_Pos delta = 0;
FT_Byte f = *flag;
if ( f & Y_SHORT_VECTOR )
{
if ( p + 1 > limit )
goto Invalid_Outline;
delta = (FT_Pos)FT_NEXT_BYTE( p );
if ( !( f & Y_POSITIVE ) )
delta = -delta;
}
else if ( !( f & SAME_Y ) )
{
if ( p + 2 > limit )
goto Invalid_Outline;
delta = (FT_Pos)FT_NEXT_SHORT( p );
}
y += delta;
vec->y = y;
/* the cast is for stupid compilers */
*flag = (FT_Byte)( f & ON_CURVE_POINT );
}
outline->n_points = (FT_Short)n_points;
outline->n_contours = (FT_Short)n_contours;
load->cursor = p;
Fail:
return error;
Invalid_Outline:
error = FT_THROW( 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_Long num_glyphs = loader->face->root.num_glyphs;
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 );
/* we reject composites that have components */
/* with invalid glyph indices */
if ( subglyph->index >= num_glyphs )
goto Invalid_Composite;
/* 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_XY_VALUES )
{
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 );
}
}
else
{
if ( subglyph->flags & ARGS_ARE_WORDS )
{
subglyph->arg1 = (FT_Int)FT_NEXT_USHORT( p );
subglyph->arg2 = (FT_Int)FT_NEXT_USHORT( p );
}
else
{
subglyph->arg1 = (FT_Int)FT_NEXT_BYTE( p );
subglyph->arg2 = (FT_Int)FT_NEXT_BYTE( p );
}
}
/* read transform */
xx = yy = 0x10000L;
xy = yx = 0;
if ( subglyph->flags & WE_HAVE_A_SCALE )
{
xx = (FT_Fixed)FT_NEXT_SHORT( p ) * 4;
yy = xx;
}
else if ( subglyph->flags & WE_HAVE_AN_XY_SCALE )
{
xx = (FT_Fixed)FT_NEXT_SHORT( p ) * 4;
yy = (FT_Fixed)FT_NEXT_SHORT( p ) * 4;
}
else if ( subglyph->flags & WE_HAVE_A_2X2 )
{
xx = (FT_Fixed)FT_NEXT_SHORT( p ) * 4;
yx = (FT_Fixed)FT_NEXT_SHORT( p ) * 4;
xy = (FT_Fixed)FT_NEXT_SHORT( p ) * 4;
yy = (FT_Fixed)FT_NEXT_SHORT( p ) * 4;
}
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;
FT_TRACE5(( " %d component%s\n",
num_subglyphs,
num_subglyphs > 1 ? "s" : "" ));
#ifdef FT_DEBUG_LEVEL_TRACE
{
FT_UInt i;
subglyph = gloader->current.subglyphs;
for ( i = 0; i < num_subglyphs; i++ )
{
if ( num_subglyphs > 1 )
FT_TRACE7(( " subglyph %d:\n", i ));
FT_TRACE7(( " glyph index: %d\n", subglyph->index ));
if ( subglyph->flags & ARGS_ARE_XY_VALUES )
FT_TRACE7(( " offset: x=%d, y=%d\n",
subglyph->arg1,
subglyph->arg2 ));
else
FT_TRACE7(( " matching points: base=%d, component=%d\n",
subglyph->arg1,
subglyph->arg2 ));
if ( subglyph->flags & WE_HAVE_A_SCALE )
FT_TRACE7(( " scaling: %f\n",
subglyph->transform.xx / 65536.0 ));
else if ( subglyph->flags & WE_HAVE_AN_XY_SCALE )
FT_TRACE7(( " scaling: x=%f, y=%f\n",
subglyph->transform.xx / 65536.0,
subglyph->transform.yy / 65536.0 ));
else if ( subglyph->flags & WE_HAVE_A_2X2 )
{
FT_TRACE7(( " scaling: xx=%f, yx=%f\n",
subglyph->transform.xx / 65536.0,
subglyph->transform.yx / 65536.0 ));
FT_TRACE7(( " xy=%f, yy=%f\n",
subglyph->transform.xy / 65536.0,
subglyph->transform.yy / 65536.0 ));
}
subglyph++;
}
}
#endif /* FT_DEBUG_LEVEL_TRACE */
#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 = FT_THROW( 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 -
(FT_UShort)start_point;
zone->n_contours = load->outline.n_contours -
(FT_Short)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 )
{
#if defined TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY || \
defined TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
TT_Face face = loader->face;
TT_Driver driver = (TT_Driver)FT_FACE_DRIVER( face );
#endif
TT_GlyphZone zone = &loader->zone;
#ifdef TT_USE_BYTECODE_INTERPRETER
FT_Long n_ins;
#else
FT_UNUSED( is_composite );
#endif
#ifdef TT_USE_BYTECODE_INTERPRETER
n_ins = loader->glyph->control_len;
/* save original point positions in `org' array */
if ( n_ins > 0 )
FT_ARRAY_COPY( zone->org, zone->cur, zone->n_points );
/* Reset graphics state. */
loader->exec->GS = 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 = loader->size->metrics->x_scale;
loader->exec->metrics.y_scale = loader->size->metrics->y_scale;
}
#endif
/* round phantom points */
zone->cur[zone->n_points - 4].x =
FT_PIX_ROUND( zone->cur[zone->n_points - 4].x );
zone->cur[zone->n_points - 3].x =
FT_PIX_ROUND( zone->cur[zone->n_points - 3].x );
zone->cur[zone->n_points - 2].y =
FT_PIX_ROUND( zone->cur[zone->n_points - 2].y );
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_Error error;
FT_GlyphLoader gloader = loader->gloader;
FT_Outline current_outline = gloader->current.outline;
TT_Set_CodeRange( loader->exec, tt_coderange_glyph,
loader->exec->glyphIns, n_ins );
loader->exec->is_composite = is_composite;
loader->exec->pts = *zone;
error = TT_Run_Context( loader->exec );
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
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
/* Save possibly modified glyph phantom points unless in v40 backward */
/* compatibility mode, where no movement on the x axis means no reason */
/* to change bearings or advance widths. */
if ( !( driver->interpreter_version == TT_INTERPRETER_VERSION_40 &&
loader->exec->backward_compatibility ) )
{
#endif
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];
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
}
#endif
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 )
{
if ( loader->exec->sph_tweak_flags & SPH_TWEAK_DEEMBOLDEN )
FT_Outline_EmboldenXY( &loader->gloader->current.outline, -24, 0 );
else if ( loader->exec->sph_tweak_flags & SPH_TWEAK_EMBOLDEN )
FT_Outline_EmboldenXY( &loader->gloader->current.outline, 24, 0 );
}
#endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */
return FT_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 = FT_Err_Ok;
FT_Outline* outline;
FT_Int n_points;
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
FT_Memory memory = loader->face->root.memory;
FT_Vector* unrounded = NULL;
#endif
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 ( !IS_DEFAULT_INSTANCE( FT_FACE( loader->face ) ) )
{
if ( FT_NEW_ARRAY( unrounded, n_points ) )
goto Exit;
/* Deltas apply to the unscaled data. */
error = TT_Vary_Apply_Glyph_Deltas( loader->face,
loader->glyph_index,
outline,
unrounded,
(FT_UInt)n_points );
/* recalculate linear horizontal and vertical advances */
/* if we don't have HVAR and VVAR, respectively */
/* XXX: change all FreeType modules to store `linear' and `vadvance' */
/* in 26.6 format before the `base' module scales them to 16.16 */
if ( !( loader->face->variation_support & TT_FACE_FLAG_VAR_HADVANCE ) )
loader->linear = FT_PIX_ROUND( unrounded[n_points - 3].x -
unrounded[n_points - 4].x ) / 64;
if ( !( loader->face->variation_support & TT_FACE_FLAG_VAR_VADVANCE ) )
loader->vadvance = FT_PIX_ROUND( unrounded[n_points - 1].x -
unrounded[n_points - 2].x ) / 64;
if ( error )
goto Exit;
}
#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 );
}
{
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
TT_Face face = loader->face;
TT_Driver driver = (TT_Driver)FT_FACE_DRIVER( face );
FT_String* family = face->root.family_name;
FT_UInt ppem = loader->size->metrics->x_ppem;
FT_String* style = face->root.style_name;
FT_UInt x_scale_factor = 1000;
#endif
FT_Vector* vec = outline->points;
FT_Vector* limit = outline->points + n_points;
FT_Fixed x_scale = 0; /* pacify compiler */
FT_Fixed y_scale = 0;
FT_Bool do_scale = FALSE;
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 )
{
/* scale, but only if enabled and only if TT hinting is being used */
if ( IS_HINTED( loader->load_flags ) )
x_scale_factor = sph_test_tweak_x_scaling( face,
family,
ppem,
style,
loader->glyph_index );
/* scale the glyph */
if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 ||
x_scale_factor != 1000 )
{
x_scale = FT_MulDiv( loader->size->metrics->x_scale,
(FT_Long)x_scale_factor, 1000 );
y_scale = loader->size->metrics->y_scale;
/* compensate for any scaling by de/emboldening; */
/* the amount was determined via experimentation */
if ( x_scale_factor != 1000 && ppem > 11 )
{
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
FT_Vector* orig_points = outline->points;
if ( !IS_DEFAULT_INSTANCE( FT_FACE( loader->face ) ) )
outline->points = unrounded;
#endif
FT_Outline_EmboldenXY( outline,
FT_MulFix( 1280 * ppem,
1000 - x_scale_factor ),
0 );
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
if ( !IS_DEFAULT_INSTANCE( FT_FACE( loader->face ) ) )
outline->points = orig_points;
#endif
}
do_scale = TRUE;
}
}
else
#endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */
{
/* scale the glyph */
if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
{
x_scale = loader->size->metrics->x_scale;
y_scale = loader->size->metrics->y_scale;
do_scale = TRUE;
}
}
if ( do_scale )
{
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
if ( !IS_DEFAULT_INSTANCE( FT_FACE( loader->face ) ) )
{
FT_Vector* u = unrounded;
for ( ; vec < limit; vec++, u++ )
{
vec->x = ( FT_MulFix( u->x, x_scale ) + 32 ) >> 6;
vec->y = ( FT_MulFix( u->y, y_scale ) + 32 ) >> 6;
}
}
else
#endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */
{
for ( ; vec < limit; vec++ )
{
vec->x = FT_MulFix( vec->x, x_scale );
vec->y = FT_MulFix( vec->y, y_scale );
}
}
}
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
/* if we have a HVAR table, `pp1' and/or `pp2' */
/* are already adjusted but unscaled */
if ( ( loader->face->variation_support & TT_FACE_FLAG_VAR_HADVANCE ) &&
IS_HINTED( loader->load_flags ) )
{
loader->pp1.x = FT_MulFix( loader->pp1.x, x_scale );
loader->pp2.x = FT_MulFix( loader->pp2.x, x_scale );
/* pp1.y and pp2.y are always zero */
}
else
#endif
{
loader->pp1 = outline->points[n_points - 4];
loader->pp2 = outline->points[n_points - 3];
}
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
/* if we have a VVAR table, `pp3' and/or `pp4' */
/* are already adjusted but unscaled */
if ( ( loader->face->variation_support & TT_FACE_FLAG_VAR_VADVANCE ) &&
IS_HINTED( loader->load_flags ) )
{
loader->pp3.x = FT_MulFix( loader->pp3.x, x_scale );
loader->pp3.y = FT_MulFix( loader->pp3.y, y_scale );
loader->pp4.x = FT_MulFix( loader->pp4.x, x_scale );
loader->pp4.y = FT_MulFix( loader->pp4.y, y_scale );
}
else
#endif
{
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 );
}
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
Exit:
FT_FREE( unrounded );
#endif
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_Outline current;
FT_Bool have_scale;
FT_Pos x, y;
current.points = gloader->base.outline.points +
num_base_points;
current.n_points = gloader->base.outline.n_points -
(short)num_base_points;
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_Outline_Transform( &current, &subglyph->transform );
/* get offset */
if ( !( subglyph->flags & ARGS_ARE_XY_VALUES ) )
{
FT_UInt num_points = (FT_UInt)gloader->base.outline.n_points;
FT_UInt k = (FT_UInt)subglyph->arg1;
FT_UInt l = (FT_UInt)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 FT_THROW( 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 FT_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 /* 1 */
/********************************************************************
*
* This algorithm is a guess and works much better than the above.
*/
FT_Fixed mac_xscale = FT_Hypot( subglyph->transform.xx,
subglyph->transform.xy );
FT_Fixed mac_yscale = FT_Hypot( subglyph->transform.yy,
subglyph->transform.yx );
x = FT_MulFix( x, mac_xscale );
y = FT_MulFix( y, mac_yscale );
#endif /* 1 */
}
if ( !( loader->load_flags & FT_LOAD_NO_SCALE ) )
{
FT_Fixed x_scale = loader->size->metrics->x_scale;
FT_Fixed y_scale = loader->size->metrics->y_scale;
x = FT_MulFix( x, x_scale );
y = FT_MulFix( y, y_scale );
if ( subglyph->flags & ROUND_XY_TO_GRID )
{
TT_Face face = loader->face;
TT_Driver driver = (TT_Driver)FT_FACE_DRIVER( face );
if ( IS_HINTED( loader->load_flags ) )
{
/*
* We round the horizontal offset only if there is hinting along
* the x axis; this corresponds to integer advance width values.
*
* Theoretically, a glyph's bytecode can toggle ClearType's
* `backward compatibility' mode, which would allow modification
* of the advance width. In reality, however, applications
* neither allow nor expect modified advance widths if subpixel
* rendering is active.
*
*/
if ( driver->interpreter_version == TT_INTERPRETER_VERSION_35 )
x = FT_PIX_ROUND( x );
y = FT_PIX_ROUND( y );
}
}
}
}
if ( x || y )
FT_Outline_Translate( &current, x, y );
return FT_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 = loader->face->max_profile.maxSizeOfInstructions;
if ( n_ins > max_ins )
{
/* don't trust `maxSizeOfInstructions'; */
/* 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 FT_THROW( 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 FT_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 = 0; 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 phantom points
*
* Defining the right side bearing (rsb) as
*
* rsb = aw - (lsb + xmax - xmin)
*
* (with `aw' the advance width, `lsb' the left side bearing, and `xmin'
* and `xmax' the glyph's minimum and maximum x value), the OpenType
* specification defines the initial position of horizontal phantom points
* as
*
* pp1 = (round(xmin - lsb), 0) ,
* pp2 = (round(pp1 + aw), 0) .
*
* Note that the rounding to the grid (in the device space) is not
* documented currently in the specification.
*
* However, the specification lacks the precise definition of vertical
* phantom points. Greg Hitchcock provided the following explanation.
*
* - a `vmtx' table is present
*
* For any glyph, the minimum and maximum y values (`ymin' and `ymax')
* are given in the `glyf' table, the top side bearing (tsb) and advance
* height (ah) are given in the `vmtx' table. The bottom side bearing
* (bsb) is then calculated as
*
* bsb = ah - (tsb + ymax - ymin) ,
*
* and the initial position of vertical phantom points is
*
* pp3 = (x, round(ymax + tsb)) ,
* pp4 = (x, round(pp3 - ah)) .
*
* See below for value `x'.
*
* - no `vmtx' table in the font
*
* If there is an `OS/2' table, we set
*
* DefaultAscender = sTypoAscender ,
* DefaultDescender = sTypoDescender ,
*
* otherwise we use data from the `hhea' table:
*
* DefaultAscender = Ascender ,
* DefaultDescender = Descender .
*
* With these two variables we can now set
*
* ah = DefaultAscender - sDefaultDescender ,
* tsb = DefaultAscender - yMax ,
*
* and proceed as if a `vmtx' table was present.
*
* Usually we have
*
* x = aw / 2 , (1)
*
* but there is one compatibility case where it can be set to
*
* x = -DefaultDescender -
* ((DefaultAscender - DefaultDescender - aw) / 2) . (2)
*
* and another one with
*
* x = 0 . (3)
*
* In Windows, the history of those values is quite complicated,
* depending on the hinting engine (that is, the graphics framework).
*
* framework from to formula
* ----------------------------------------------------------
* GDI Windows 98 current (1)
* (Windows 2000 for NT)
* GDI+ Windows XP Windows 7 (2)
* GDI+ Windows 8 current (3)
* DWrite Windows 7 current (3)
*
* For simplicity, FreeType uses (1) for grayscale subpixel hinting and
* (3) for everything else.
*
*/
static void
tt_loader_set_pp( TT_Loader loader )
{
FT_Bool subpixel_hinting = 0;
FT_Bool grayscale = 0;
FT_Bool use_aw_2 = 0;
#ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
TT_Driver driver = (TT_Driver)FT_FACE_DRIVER( loader->face );
#endif
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 )
{
subpixel_hinting = loader->exec ? loader->exec->subpixel_hinting
: 0;
grayscale = loader->exec ? loader->exec->grayscale
: 0;
}
#endif
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
if ( driver->interpreter_version == TT_INTERPRETER_VERSION_40 )
{
subpixel_hinting = loader->exec ? loader->exec->subpixel_hinting_lean
: 0;
grayscale = loader->exec ? loader->exec->grayscale_cleartype
: 0;
}
#endif
use_aw_2 = FT_BOOL( subpixel_hinting && grayscale );
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 = use_aw_2 ? loader->advance / 2 : 0;
loader->pp3.y = loader->bbox.yMax + loader->top_bearing;
loader->pp4.x = use_aw_2 ? loader->advance / 2 : 0;
loader->pp4.y = loader->pp3.y - loader->vadvance;
}
/* a utility function to retrieve i-th node from given FT_List */
static FT_ListNode
ft_list_get_node_at( FT_List list,
FT_UInt idx )
{
FT_ListNode cur;
if ( !list )
return NULL;
for ( cur = list->head; cur; cur = cur->next )
{
if ( !idx )
return cur;
idx--;
}
return NULL;
}
/**************************************************************************
*
* @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 = FT_Err_Ok;
FT_Fixed x_scale, y_scale;
FT_ULong offset;
TT_Face face = loader->face;
FT_GlyphLoader gloader = loader->gloader;
FT_Bool opened_frame = 0;
#ifdef FT_CONFIG_OPTION_INCREMENTAL
FT_StreamRec inc_stream;
FT_Data glyph_data;
FT_Bool glyph_data_loaded = 0;
#endif
#ifdef FT_DEBUG_LEVEL_TRACE
if ( recurse_count )
FT_TRACE5(( " nesting level: %d\n", recurse_count ));
#endif
/* some fonts have an incorrect value of `maxComponentDepth' */
if ( recurse_count > face->max_profile.maxComponentDepth )
{
FT_TRACE1(( "load_truetype_glyph: maxComponentDepth set to %d\n",
recurse_count ));
face->max_profile.maxComponentDepth = (FT_UShort)recurse_count;
}
#ifndef FT_CONFIG_OPTION_INCREMENTAL
/* check glyph index */
if ( glyph_index >= (FT_UInt)face->root.num_glyphs )
{
error = FT_THROW( Invalid_Glyph_Index );
goto Exit;
}
#endif
loader->glyph_index = glyph_index;
if ( loader->load_flags & FT_LOAD_NO_SCALE )
{
x_scale = 0x10000L;
y_scale = 0x10000L;
}
else
{
x_scale = loader->size->metrics->x_scale;
y_scale = loader->size->metrics->y_scale;
}
/* 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_ZERO( &inc_stream );
FT_Stream_OpenMemory( &inc_stream,
glyph_data.pointer,
(FT_ULong)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 ( !face->glyf_offset &&
!face->root.internal->incremental_interface )
#else
if ( !face->glyf_offset )
#endif /* FT_CONFIG_OPTION_INCREMENTAL */
{
FT_TRACE2(( "no `glyf' table but non-zero `loca' entry\n" ));
error = FT_THROW( Invalid_Table );
goto Exit;
}
error = face->access_glyph_frame( loader, glyph_index,
face->glyf_offset + offset,
(FT_UInt)loader->byte_len );
if ( error )
goto Exit;
/* read glyph header first */
error = face->read_glyph_header( loader );
face->forget_glyph_frame( loader );
if ( error )
goto Exit;
}
/* a space glyph */
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;
}
/* the metrics must be computed after loading the glyph header */
/* since we need the glyph's `yMax' value in case the vertical */
/* metrics must be emulated */
error = tt_get_metrics( loader, glyph_index );
if ( error )
goto Exit;
if ( header_only )
goto Exit;
if ( loader->byte_len == 0 || loader->n_contours == 0 )
{
#ifdef FT_CONFIG_OPTION_INCREMENTAL
tt_get_metrics_incremental( loader, glyph_index );
#endif
tt_loader_set_pp( loader );
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
if ( FT_IS_NAMED_INSTANCE( FT_FACE( face ) ) ||
FT_IS_VARIATION( FT_FACE( face ) ) )
{
/* a small outline structure with four elements for */
/* communication with `TT_Vary_Apply_Glyph_Deltas' */
FT_Vector points[4];
char tags[4] = { 1, 1, 1, 1 };
short contours[4] = { 0, 1, 2, 3 };
FT_Outline outline;
/* unrounded values */
FT_Vector unrounded[4] = { {0, 0}, {0, 0}, {0, 0}, {0, 0} };
points[0].x = loader->pp1.x;
points[0].y = loader->pp1.y;
points[1].x = loader->pp2.x;
points[1].y = loader->pp2.y;
points[2].x = loader->pp3.x;
points[2].y = loader->pp3.y;
points[3].x = loader->pp4.x;
points[3].y = loader->pp4.y;
outline.n_points = 4;
outline.n_contours = 4;
outline.points = points;
outline.tags = tags;
outline.contours = contours;
/* this must be done before scaling */
error = TT_Vary_Apply_Glyph_Deltas( loader->face,
glyph_index,
&outline,
unrounded,
(FT_UInt)outline.n_points );
if ( error )
goto Exit;
loader->pp1.x = points[0].x;
loader->pp1.y = points[0].y;
loader->pp2.x = points[1].x;
loader->pp2.y = points[1].y;
loader->pp3.x = points[2].x;
loader->pp3.y = points[2].y;
loader->pp4.x = points[3].x;
loader->pp4.y = points[3].y;
/* recalculate linear horizontal and vertical advances */
/* if we don't have HVAR and VVAR, respectively */
if ( !( loader->face->variation_support & TT_FACE_FLAG_VAR_HADVANCE ) )
loader->linear = FT_PIX_ROUND( unrounded[1].x -
unrounded[0].x ) / 64;
if ( !( loader->face->variation_support & TT_FACE_FLAG_VAR_VADVANCE ) )
loader->vadvance = FT_PIX_ROUND( unrounded[3].x -
unrounded[2].x ) / 64;
}
#endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */
/* scale phantom points, if necessary; */
/* they get rounded in `TT_Hint_Glyph' */
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 );
/* pp1.y and pp2.y are always zero */
loader->pp3.x = FT_MulFix( loader->pp3.x, x_scale );
loader->pp3.y = FT_MulFix( loader->pp3.y, y_scale );
loader->pp4.x = FT_MulFix( loader->pp4.x, x_scale );
loader->pp4.y = FT_MulFix( loader->pp4.y, y_scale );
}
error = FT_Err_Ok;
goto Exit;
}
#ifdef FT_CONFIG_OPTION_INCREMENTAL
tt_get_metrics_incremental( loader, glyph_index );
#endif
tt_loader_set_pp( loader );
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
/* we now open a frame again, right after the glyph header */
/* (which consists of 10 bytes) */
error = face->access_glyph_frame( loader, glyph_index,
face->glyf_offset + offset + 10,
(FT_UInt)loader->byte_len - 10 );
if ( error )
goto Exit;
opened_frame = 1;
/* 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 < 0 )
{
FT_Memory memory = face->root.memory;
FT_UInt start_point;
FT_UInt start_contour;
FT_ULong ins_pos; /* position of composite instructions, if any */
FT_ListNode node, node2;
/* normalize the `n_contours' value */
loader->n_contours = -1;
/*
* We store the glyph index directly in the `node->data' pointer,
* following the glib solution (cf. macro `GUINT_TO_POINTER') with a
* double cast to make this portable. Note, however, that this needs
* pointers with a width of at least 32 bits.
*/
/* clear the nodes filled by sibling chains */
node = ft_list_get_node_at( &loader->composites, recurse_count );
for ( node2 = node; node2; node2 = node2->next )
node2->data = (void*)FT_ULONG_MAX;
/* check whether we already have a composite glyph with this index */
if ( FT_List_Find( &loader->composites,
FT_UINT_TO_POINTER( glyph_index ) ) )
{
FT_TRACE1(( "TT_Load_Composite_Glyph:"
" infinite recursion detected\n" ));
error = FT_THROW( Invalid_Composite );
goto Exit;
}
else if ( node )
node->data = FT_UINT_TO_POINTER( glyph_index );
else
{
if ( FT_NEW( node ) )
goto Exit;
node->data = FT_UINT_TO_POINTER( glyph_index );
FT_List_Add( &loader->composites, node );
}
start_point = (FT_UInt)gloader->base.outline.n_points;
start_contour = (FT_UInt)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 ( FT_IS_NAMED_INSTANCE( FT_FACE( face ) ) ||
FT_IS_VARIATION( FT_FACE( face ) ) )
{
short i, limit;
FT_SubGlyph subglyph;
FT_Outline outline;
FT_Vector* points = NULL;
char* tags = NULL;
short* contours = NULL;
FT_Vector* unrounded = NULL;
limit = (short)gloader->current.num_subglyphs;
/* construct an outline structure for */
/* communication with `TT_Vary_Apply_Glyph_Deltas' */
outline.n_points = (short)( gloader->current.num_subglyphs + 4 );
outline.n_contours = outline.n_points;
outline.points = NULL;
outline.tags = NULL;
outline.contours = NULL;
if ( FT_NEW_ARRAY( points, outline.n_points ) ||
FT_NEW_ARRAY( tags, outline.n_points ) ||
FT_NEW_ARRAY( contours, outline.n_points ) ||
FT_NEW_ARRAY( unrounded, outline.n_points ) )
goto Exit1;
subglyph = gloader->current.subglyphs;
for ( i = 0; i < limit; i++, subglyph++ )
{
/* applying deltas for anchor points doesn't make sense, */
/* but we don't have to specially check this since */
/* unused delta values are zero anyways */
points[i].x = subglyph->arg1;
points[i].y = subglyph->arg2;
tags[i] = 1;
contours[i] = i;
}
points[i].x = loader->pp1.x;
points[i].y = loader->pp1.y;
tags[i] = 1;
contours[i] = i;
i++;
points[i].x = loader->pp2.x;
points[i].y = loader->pp2.y;
tags[i] = 1;
contours[i] = i;
i++;
points[i].x = loader->pp3.x;
points[i].y = loader->pp3.y;
tags[i] = 1;
contours[i] = i;
i++;
points[i].x = loader->pp4.x;
points[i].y = loader->pp4.y;
tags[i] = 1;
contours[i] = i;
outline.points = points;
outline.tags = tags;
outline.contours = contours;
/* this call provides additional offsets */
/* for each component's translation */
if ( FT_SET_ERROR( TT_Vary_Apply_Glyph_Deltas(
face,
glyph_index,
&outline,
unrounded,
(FT_UInt)outline.n_points ) ) )
goto Exit1;
subglyph = gloader->current.subglyphs;
for ( i = 0; i < limit; i++, subglyph++ )
{
if ( subglyph->flags & ARGS_ARE_XY_VALUES )
{
subglyph->arg1 = (FT_Int16)points[i].x;
subglyph->arg2 = (FT_Int16)points[i].y;
}
}
loader->pp1.x = points[i + 0].x;
loader->pp1.y = points[i + 0].y;
loader->pp2.x = points[i + 1].x;
loader->pp2.y = points[i + 1].y;
loader->pp3.x = points[i + 2].x;
loader->pp3.y = points[i + 2].y;
loader->pp4.x = points[i + 3].x;
loader->pp4.y = points[i + 3].y;
/* recalculate linear horizontal and vertical advances */
/* if we don't have HVAR and VVAR, respectively */
if ( !( face->variation_support & TT_FACE_FLAG_VAR_HADVANCE ) )
loader->linear =
FT_PIX_ROUND( unrounded[outline.n_points - 3].x -
unrounded[outline.n_points - 4].x ) / 64;
if ( !( face->variation_support & TT_FACE_FLAG_VAR_VADVANCE ) )
loader->vadvance =
FT_PIX_ROUND( unrounded[outline.n_points - 1].x -
unrounded[outline.n_points - 2].x ) / 64;
Exit1:
FT_FREE( outline.points );
FT_FREE( outline.tags );
FT_FREE( outline.contours );
FT_FREE( unrounded );
if ( error )
goto Exit;
}
#endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */
/* scale phantom points, if necessary; */
/* they get rounded in `TT_Hint_Glyph' */
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 );
/* pp1.y and pp2.y are always zero */
loader->pp3.x = FT_MulFix( loader->pp3.x, x_scale );
loader->pp3.y = FT_MulFix( loader->pp3.y, y_scale );
loader->pp4.x = FT_MulFix( loader->pp4.x, x_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 = NULL;
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];
FT_Int linear_hadvance;
FT_Int linear_vadvance;
/* 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;
linear_hadvance = loader->linear;
linear_vadvance = loader->vadvance;
num_base_points = (FT_UInt)gloader->base.outline.n_points;
error = load_truetype_glyph( loader,
(FT_UInt)subglyph->index,
recurse_count + 1,
FALSE );
if ( error )
goto Exit;
/* restore subglyph pointer */
subglyph = gloader->base.subglyphs + num_base_subgs + n;
/* restore phantom points if necessary */
if ( !( subglyph->flags & USE_MY_METRICS ) )
{
loader->pp1 = pp[0];
loader->pp2 = pp[1];
loader->pp3 = pp[2];
loader->pp4 = pp[3];
loader->linear = linear_hadvance;
loader->vadvance = linear_vadvance;
}
num_points = (FT_UInt)gloader->base.outline.n_points;
if ( num_points == num_base_points )
continue;
/* gloader->base.outline consists of three parts: */
/* */
/* 0 ----> start_point ----> num_base_points ----> n_points */
/* (1) (2) (3) */
/* */
/* (1) points that exist from the beginning */
/* (2) component points that have been loaded so far */
/* (3) points of the newly loaded component */
error = TT_Process_Composite_Component( loader,
subglyph,
start_point,
num_base_points );
if ( error )
goto Exit;
}
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 &&
subglyph->flags & WE_HAVE_INSTR &&
#endif
num_points > start_point )
{
error = TT_Process_Composite_Glyph( loader,
start_point,
start_contour );
if ( error )
goto Exit;
}
}
/* retain the overlap flag */
if ( gloader->base.num_subglyphs &&
gloader->base.subglyphs[0].flags & OVERLAP_COMPOUND )
gloader->base.outline.flags |= FT_OUTLINE_OVERLAP;
}
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
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 )
{
TT_Face face = loader->face;
#if defined TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY || \
defined TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
TT_Driver driver = (TT_Driver)FT_FACE_DRIVER( face );
#endif
FT_BBox bbox;
FT_Fixed y_scale;
TT_GlyphSlot glyph = loader->glyph;
TT_Size size = loader->size;
y_scale = 0x10000L;
if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
y_scale = size->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 = SUB_LONG(loader->pp2.x, loader->pp1.x);
/* Adjust advance width to the value contained in the hdmx table */
/* unless FT_LOAD_COMPUTE_METRICS is set or backward compatibility */
/* mode of the v40 interpreter is active. See `ttinterp.h' for */
/* details on backward compatibility mode. */
if (
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
!( driver->interpreter_version == TT_INTERPRETER_VERSION_40 &&
( loader->exec && loader->exec->backward_compatibility ) ) &&
#endif
!face->postscript.isFixedPitch &&
IS_HINTED( loader->load_flags ) &&
!( loader->load_flags & FT_LOAD_COMPUTE_METRICS ) )
{
FT_Byte* widthp;
widthp = tt_face_get_device_metrics( face,
size->metrics->x_ppem,
glyph_index );
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 )
{
FT_Bool ignore_x_mode;
ignore_x_mode = FT_BOOL( FT_LOAD_TARGET_MODE( loader->load_flags ) !=
FT_RENDER_MODE_MONO );
if ( widthp &&
( ( ignore_x_mode && loader->exec->compatible_widths ) ||
!ignore_x_mode ||
SPH_OPTION_BITMAP_WIDTHS ) )
glyph->metrics.horiAdvance = *widthp * 64;
}
else
#endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */
{
if ( widthp )
glyph->metrics.horiAdvance = *widthp * 64;
}
}
/* set glyph dimensions */
glyph->metrics.width = SUB_LONG( bbox.xMax, bbox.xMin );
glyph->metrics.height = SUB_LONG( 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( SUB_LONG( loader->pp3.y, bbox.yMax ),
y_scale );
if ( loader->pp3.y <= loader->pp4.y )
advance = 0;
else
advance = (FT_UShort)FT_DivFix( SUB_LONG( 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( SUB_LONG( 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 incr_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 )
{
incr_metrics.bearing_x = 0;
incr_metrics.bearing_y = top;
incr_metrics.advance = advance;
error = incr->funcs->get_glyph_metrics( incr->object,
glyph_index,
TRUE,
&incr_metrics );
if ( error )
return error;
top = incr_metrics.bearing_y;
advance = incr_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 = SUB_LONG( glyph->metrics.horiBearingX,
glyph->metrics.horiAdvance / 2 );
glyph->metrics.vertBearingY = top;
glyph->metrics.vertAdvance = advance;
}
return FT_Err_Ok;
}
#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 sbit_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_UInt)load_flags,
stream,
&glyph->bitmap,
&sbit_metrics );
if ( !error )
{
glyph->outline.n_points = 0;
glyph->outline.n_contours = 0;
glyph->metrics.width = (FT_Pos)sbit_metrics.width * 64;
glyph->metrics.height = (FT_Pos)sbit_metrics.height * 64;
glyph->metrics.horiBearingX = (FT_Pos)sbit_metrics.horiBearingX * 64;
glyph->metrics.horiBearingY = (FT_Pos)sbit_metrics.horiBearingY * 64;
glyph->metrics.horiAdvance = (FT_Pos)sbit_metrics.horiAdvance * 64;
glyph->metrics.vertBearingX = (FT_Pos)sbit_metrics.vertBearingX * 64;
glyph->metrics.vertBearingY = (FT_Pos)sbit_metrics.vertBearingY * 64;
glyph->metrics.vertAdvance = (FT_Pos)sbit_metrics.vertAdvance * 64;
glyph->format = FT_GLYPH_FORMAT_BITMAP;
if ( load_flags & FT_LOAD_VERTICAL_LAYOUT )
{
glyph->bitmap_left = sbit_metrics.vertBearingX;
glyph->bitmap_top = sbit_metrics.vertBearingY;
}
else
{
glyph->bitmap_left = sbit_metrics.horiBearingX;
glyph->bitmap_top = sbit_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;
#ifdef TT_USE_BYTECODE_INTERPRETER
FT_Error error;
FT_Bool pedantic = FT_BOOL( load_flags & FT_LOAD_PEDANTIC );
#if defined TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY || \
defined TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
TT_Driver driver = (TT_Driver)FT_FACE_DRIVER( (TT_Face)glyph->face );
#endif
#endif
face = (TT_Face)glyph->face;
stream = face->root.stream;
FT_ZERO( loader );
#ifdef TT_USE_BYTECODE_INTERPRETER
/* load execution context */
if ( IS_HINTED( load_flags ) && !glyf_table_only )
{
TT_ExecContext exec;
FT_Bool grayscale = TRUE;
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
FT_Bool subpixel_hinting_lean;
FT_Bool grayscale_cleartype;
#endif
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
FT_Bool subpixel_hinting = FALSE;
#if 0
/* not used yet */
FT_Bool compatible_widths;
FT_Bool symmetrical_smoothing;
FT_Bool bgr;
FT_Bool vertical_lcd;
FT_Bool subpixel_positioned;
FT_Bool gray_cleartype;
#endif
#endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */
FT_Bool reexecute = FALSE;
if ( size->bytecode_ready < 0 || size->cvt_ready < 0 )
{
error = tt_size_ready_bytecode( size, pedantic );
if ( error )
return error;
}
else if ( size->bytecode_ready )
return size->bytecode_ready;
else if ( size->cvt_ready )
return size->cvt_ready;
/* query new execution context */
exec = size->context;
if ( !exec )
return FT_THROW( Could_Not_Find_Context );
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
if ( driver->interpreter_version == TT_INTERPRETER_VERSION_40 )
{
subpixel_hinting_lean =
FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) !=
FT_RENDER_MODE_MONO );
grayscale_cleartype =
FT_BOOL( subpixel_hinting_lean &&
!( ( load_flags &
FT_LOAD_TARGET_LCD ) ||
( load_flags &
FT_LOAD_TARGET_LCD_V ) ) );
exec->vertical_lcd_lean =
FT_BOOL( subpixel_hinting_lean &&
( load_flags &
FT_LOAD_TARGET_LCD_V ) );
}
else
{
subpixel_hinting_lean = FALSE;
grayscale_cleartype = FALSE;
exec->vertical_lcd_lean = FALSE;
}
#endif
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 )
{
subpixel_hinting = FT_BOOL( ( FT_LOAD_TARGET_MODE( load_flags ) !=
FT_RENDER_MODE_MONO ) &&
SPH_OPTION_SET_SUBPIXEL );
if ( subpixel_hinting )
grayscale = FALSE;
else if ( SPH_OPTION_SET_GRAYSCALE )
{
grayscale = TRUE;
subpixel_hinting = FALSE;
}
else
grayscale = FALSE;
if ( FT_IS_TRICKY( glyph->face ) )
subpixel_hinting = FALSE;
exec->ignore_x_mode = subpixel_hinting || grayscale;
exec->rasterizer_version = SPH_OPTION_SET_RASTERIZER_VERSION;
if ( exec->sph_tweak_flags & SPH_TWEAK_RASTERIZER_35 )
exec->rasterizer_version = TT_INTERPRETER_VERSION_35;
#if 1
exec->compatible_widths = SPH_OPTION_SET_COMPATIBLE_WIDTHS;
exec->symmetrical_smoothing = TRUE;
exec->bgr = FALSE;
exec->vertical_lcd = FALSE;
exec->subpixel_positioned = TRUE;
exec->gray_cleartype = FALSE;
#else /* 0 */
exec->compatible_widths =
FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) !=
TT_LOAD_COMPATIBLE_WIDTHS );
exec->symmetrical_smoothing =
FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) !=
TT_LOAD_SYMMETRICAL_SMOOTHING );
exec->bgr =
FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) !=
TT_LOAD_BGR );
exec->vertical_lcd =
FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) !=
TT_LOAD_VERTICAL_LCD );
exec->subpixel_positioned =
FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) !=
TT_LOAD_SUBPIXEL_POSITIONED );
exec->gray_cleartype =
FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) !=
TT_LOAD_GRAY_CLEARTYPE );
#endif /* 0 */
}
else
#endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
if ( driver->interpreter_version == TT_INTERPRETER_VERSION_40 )
grayscale = FT_BOOL( !subpixel_hinting_lean &&
FT_LOAD_TARGET_MODE( load_flags ) !=
FT_RENDER_MODE_MONO );
else
#endif
grayscale = FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) !=
FT_RENDER_MODE_MONO );
error = TT_Load_Context( exec, face, size );
if ( error )
return error;
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 )
{
/* a change from mono to subpixel rendering (and vice versa) */
/* requires a re-execution of the CVT program */
if ( subpixel_hinting != exec->subpixel_hinting )
{
FT_TRACE4(( "tt_loader_init: subpixel hinting change,"
" re-executing `prep' table\n" ));
exec->subpixel_hinting = subpixel_hinting;
reexecute = TRUE;
}
/* a change from mono to grayscale rendering (and vice versa) */
/* requires a re-execution of the CVT program */
if ( grayscale != exec->grayscale )
{
FT_TRACE4(( "tt_loader_init: grayscale hinting change,"
" re-executing `prep' table\n" ));
exec->grayscale = grayscale;
reexecute = TRUE;
}
}
else
#endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */
{
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
if ( driver->interpreter_version == TT_INTERPRETER_VERSION_40 )
{
/* a change from mono to subpixel rendering (and vice versa) */
/* requires a re-execution of the CVT program */
if ( subpixel_hinting_lean != exec->subpixel_hinting_lean )
{
FT_TRACE4(( "tt_loader_init: subpixel hinting change,"
" re-executing `prep' table\n" ));
exec->subpixel_hinting_lean = subpixel_hinting_lean;
reexecute = TRUE;
}
/* a change from colored to grayscale subpixel rendering (and */
/* vice versa) requires a re-execution of the CVT program */
if ( grayscale_cleartype != exec->grayscale_cleartype )
{
FT_TRACE4(( "tt_loader_init: grayscale subpixel hinting change,"
" re-executing `prep' table\n" ));
exec->grayscale_cleartype = grayscale_cleartype;
reexecute = TRUE;
}
}
#endif
/* a change from mono to grayscale rendering (and vice versa) */
/* requires a re-execution of the CVT program */
if ( grayscale != exec->grayscale )
{
FT_TRACE4(( "tt_loader_init: grayscale hinting change,"
" re-executing `prep' table\n" ));
exec->grayscale = grayscale;
reexecute = TRUE;
}
}
if ( reexecute )
{
error = tt_size_run_prep( size, pedantic );
if ( error )
return error;
}
/* check 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;
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
/* check whether we have a font hinted for ClearType -- */
/* note that this flag can also be modified in a glyph's bytecode */
if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 &&
exec->GS.instruct_control & 4 )
exec->ignore_x_mode = 0;
#endif
exec->pedantic_hinting = FT_BOOL( load_flags & FT_LOAD_PEDANTIC );
loader->exec = exec;
loader->instructions = exec->glyphIns;
}
#endif /* TT_USE_BYTECODE_INTERPRETER */
/* 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 = (FT_ULong)load_flags;
loader->face = face;
loader->size = size;
loader->glyph = (FT_GlyphSlot)glyph;
loader->stream = stream;
loader->composites.head = NULL;
loader->composites.tail = NULL;
return FT_Err_Ok;
}
static void
tt_loader_done( TT_Loader loader )
{
FT_List_Finalize( &loader->composites,
NULL,
loader->face->root.memory,
NULL );
}
/**************************************************************************
*
* @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 )
{
FT_Error error;
TT_LoaderRec loader;
FT_TRACE1(( "TT_Load_Glyph: glyph index %d\n", glyph_index ));
#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
/* try to load embedded bitmap (if any) */
if ( size->strike_index != 0xFFFFFFFFUL &&
( load_flags & FT_LOAD_NO_BITMAP ) == 0 &&
IS_DEFAULT_INSTANCE( glyph->face ) )
{
FT_Fixed x_scale = size->root.metrics.x_scale;
FT_Fixed y_scale = size->root.metrics.y_scale;
error = load_sbit_image( size, glyph, glyph_index, load_flags );
if ( FT_ERR_EQ( error, Missing_Bitmap ) )
{
/* the bitmap strike is incomplete and misses the requested glyph; */
/* if we have a bitmap-only font, return an empty glyph */
if ( !FT_IS_SCALABLE( glyph->face ) )
{
TT_Face face = (TT_Face)glyph->face;
FT_Short left_bearing = 0;
FT_Short top_bearing = 0;
FT_UShort advance_width = 0;
FT_UShort advance_height = 0;
/* to return an empty glyph, however, we need metrics data */
/* from the `hmtx' (or `vmtx') table; the assumption is that */
/* empty glyphs are missing intentionally, representing */
/* whitespace - not having at least horizontal metrics is */
/* thus considered an error */
if ( !face->horz_metrics_size )
return error;
/* we now construct an empty bitmap glyph */
TT_Get_HMetrics( face, glyph_index,
&left_bearing,
&advance_width );
TT_Get_VMetrics( face, glyph_index,
0,
&top_bearing,
&advance_height );
glyph->outline.n_points = 0;
glyph->outline.n_contours = 0;
glyph->metrics.width = 0;
glyph->metrics.height = 0;
glyph->metrics.horiBearingX = FT_MulFix( left_bearing, x_scale );
glyph->metrics.horiBearingY = 0;
glyph->metrics.horiAdvance = FT_MulFix( advance_width, x_scale );
glyph->metrics.vertBearingX = 0;
glyph->metrics.vertBearingY = FT_MulFix( top_bearing, y_scale );
glyph->metrics.vertAdvance = FT_MulFix( advance_height, y_scale );
glyph->format = FT_GLYPH_FORMAT_BITMAP;
glyph->bitmap.pixel_mode = FT_PIXEL_MODE_MONO;
glyph->bitmap_left = 0;
glyph->bitmap_top = 0;
return FT_Err_Ok;
}
}
else if ( error )
{
/* return error if font is not scalable */
if ( !FT_IS_SCALABLE( glyph->face ) )
return error;
}
else
{
if ( FT_IS_SCALABLE( glyph->face ) )
{
/* 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 );
tt_loader_done( &loader );
glyph->linearHoriAdvance = loader.linear;
glyph->linearVertAdvance = loader.vadvance;
/* sanity checks: if `xxxAdvance' in the sbit metric */
/* structure isn't set, use `linearXXXAdvance' */
if ( !glyph->metrics.horiAdvance && glyph->linearHoriAdvance )
glyph->metrics.horiAdvance = FT_MulFix( glyph->linearHoriAdvance,
x_scale );
if ( !glyph->metrics.vertAdvance && glyph->linearVertAdvance )
glyph->metrics.vertAdvance = FT_MulFix( glyph->linearVertAdvance,
y_scale );
}
return FT_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 )
{
error = FT_THROW( Invalid_Size_Handle );
goto Exit;
}
if ( load_flags & FT_LOAD_SBITS_ONLY )
{
error = FT_THROW( Invalid_Argument );
goto Exit;
}
error = tt_loader_init( &loader, size, glyph, load_flags, FALSE );
if ( error )
goto Exit;
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 */
error = 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->metrics->y_ppem < 24 )
glyph->outline.flags |= FT_OUTLINE_HIGH_PRECISION;
FT_TRACE1(( " subglyphs = %u, contours = %hd, points = %hd,"
" flags = 0x%.3x\n",
loader.gloader->base.num_subglyphs,
glyph->outline.n_contours,
glyph->outline.n_points,
glyph->outline.flags ));
tt_loader_done( &loader );
Exit:
#ifdef FT_DEBUG_LEVEL_TRACE
if ( error )
FT_TRACE1(( " failed (error code 0x%x)\n",
error ));
#endif
return error;
}
/* END */
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