ref: bf9b1ef90564987856a42461147435f143e9e7cd
dir: /src/truetype/ttgload.c/
/****************************************************************************
*
* 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( ¤t, &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( ¤t, 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 = %hu\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 ( n_ins > loader->byte_len )
{
FT_TRACE1(( "TT_Process_Composite_Glyph:"
" too many instructions (%hu) for glyph with length %u\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,
glyph_data.length );
loader->stream = &inc_stream;
}
else
#endif /* FT_CONFIG_OPTION_INCREMENTAL */
offset = tt_face_get_location( face, glyph_index, &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,
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,
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*)-1;
/* 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_QNEW( 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_UInt 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;
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;
if ( loader->widthp )
glyph->metrics.horiAdvance = loader->widthp[glyph_index] * 64;
else
glyph->metrics.horiAdvance = SUB_LONG(loader->pp2.x, loader->pp1.x);
/* 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;
error = TT_Load_Context( exec, face, size );
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 = FALSE;
#endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
/*
* Toggle backward compatibility according to what font wants, except
* when
*
* 1) we have a `tricky' font that heavily relies on the interpreter to
* render glyphs correctly, for example DFKai-SB, or
* 2) FT_RENDER_MODE_MONO (i.e, monochome rendering) is requested.
*
* In those cases, backward compatibility needs to be turned off to get
* correct rendering. The rendering is then completely up to the
* font's programming.
*
*/
if ( driver->interpreter_version == TT_INTERPRETER_VERSION_40 &&
subpixel_hinting_lean &&
!FT_IS_TRICKY( glyph->face ) )
exec->backward_compatibility = !( exec->GS.instruct_control & 4 );
else
exec->backward_compatibility = FALSE;
#endif /* TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL */
exec->pedantic_hinting = FT_BOOL( load_flags & FT_LOAD_PEDANTIC );
loader->exec = exec;
loader->instructions = exec->glyphIns;
/* Use the hdmx table if any unless FT_LOAD_COMPUTE_METRICS */
/* is set or backward compatibility mode of the v38 or v40 */
/* interpreters is active. See `ttinterp.h' for details on */
/* backward compatibility mode. */
if ( IS_HINTED( loader->load_flags ) &&
!( loader->load_flags & FT_LOAD_COMPUTE_METRICS ) &&
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
!( driver->interpreter_version == TT_INTERPRETER_VERSION_40 &&
exec->backward_compatibility ) &&
#endif
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
!( driver->interpreter_version == TT_INTERPRETER_VERSION_38 &&
!SPH_OPTION_BITMAP_WIDTHS &&
FT_LOAD_TARGET_MODE( loader->load_flags ) !=
FT_RENDER_MODE_MONO &&
exec->compatible_widths ) &&
#endif
!face->postscript.isFixedPitch )
{
loader->widthp = size->widthp;
}
else
loader->widthp = NULL;
}
#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;
/* done if we are only interested in the `hdmx` advance */
if ( load_flags & FT_LOAD_ADVANCE_ONLY &&
!( load_flags & FT_LOAD_VERTICAL_LAYOUT ) &&
loader.widthp )
{
glyph->metrics.horiAdvance = loader.widthp[glyph_index] * 64;
goto Done;
}
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 ));
Done:
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 */