ref: 6c2ab0977cd6d443fe845f88c9846bda2944622a
dir: /src/truetype/ttgload.c/
/***************************************************************************/
/* */
/* ttgload.c */
/* */
/* TrueType Glyph Loader (body). */
/* */
/* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007 by */
/* David Turner, Robert Wilhelm, and Werner Lemberg. */
/* */
/* This file is part of the FreeType project, and may only be used, */
/* modified, and distributed under the terms of the FreeType project */
/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
/* this file you indicate that you have read the license and */
/* understand and accept it fully. */
/* */
/***************************************************************************/
#include <ft2build.h>
#include FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_CALC_H
#include FT_INTERNAL_STREAM_H
#include FT_INTERNAL_SFNT_H
#include FT_TRUETYPE_TAGS_H
#include FT_OUTLINE_H
#include "ttgload.h"
#include "ttpload.h"
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
#include "ttgxvar.h"
#endif
#include "tterrors.h"
/*************************************************************************/
/* */
/* The macro FT_COMPONENT is used in trace mode. It is an implicit */
/* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */
/* messages during execution. */
/* */
#undef FT_COMPONENT
#define FT_COMPONENT trace_ttgload
/*************************************************************************/
/* */
/* Composite font flags. */
/* */
#define ARGS_ARE_WORDS 0x0001
#define ARGS_ARE_XY_VALUES 0x0002
#define ROUND_XY_TO_GRID 0x0004
#define WE_HAVE_A_SCALE 0x0008
/* reserved 0x0010 */
#define MORE_COMPONENTS 0x0020
#define WE_HAVE_AN_XY_SCALE 0x0040
#define WE_HAVE_A_2X2 0x0080
#define WE_HAVE_INSTR 0x0100
#define USE_MY_METRICS 0x0200
#define OVERLAP_COMPOUND 0x0400
#define SCALED_COMPONENT_OFFSET 0x0800
#define UNSCALED_COMPONENT_OFFSET 0x1000
/*************************************************************************/
/* */
/* Returns the horizontal metrics in font units for a given glyph. If */
/* `check' is true, take care of monospaced fonts by returning the */
/* advance width maximum. */
/* */
static void
Get_HMetrics( TT_Face face,
FT_UInt idx,
FT_Bool check,
FT_Short* lsb,
FT_UShort* aw )
{
( (SFNT_Service)face->sfnt )->get_metrics( face, 0, idx, lsb, aw );
if ( check && face->postscript.isFixedPitch )
*aw = face->horizontal.advance_Width_Max;
}
/*************************************************************************/
/* */
/* Returns the vertical metrics in font units for a given glyph. */
/* Greg Hitchcock from Microsoft told us that if there were no `vmtx' */
/* table, typoAscender/Descender from the `OS/2' table would be used */
/* instead, and if there were no `OS/2' table, use ascender/descender */
/* from the `hhea' table. But that is not what Microsoft's rasterizer */
/* apparently does: It uses the ppem value as the advance height, and */
/* sets the top side bearing to be zero. */
/* */
/* The monospace `check' is probably not meaningful here, but we leave */
/* it in for a consistent interface. */
/* */
static void
Get_VMetrics( TT_Face face,
FT_UInt idx,
FT_Bool check,
FT_Short* tsb,
FT_UShort* ah )
{
FT_UNUSED( check );
if ( face->vertical_info )
( (SFNT_Service)face->sfnt )->get_metrics( face, 1, idx, tsb, ah );
#if 1 /* Empirically determined, at variance with what MS said */
else
{
*tsb = 0;
*ah = face->root.units_per_EM;
}
#else /* This is what MS said to do. It isn't what they do, however. */
else if ( face->os2.version != 0xFFFFU )
{
*tsb = face->os2.sTypoAscender;
*ah = face->os2.sTypoAscender - face->os2.sTypoDescender;
}
else
{
*tsb = face->horizontal.Ascender;
*ah = face->horizontal.Ascender - face->horizontal.Descender;
}
#endif
}
/*************************************************************************/
/* */
/* Translates an array of coordinates. */
/* */
static void
translate_array( FT_UInt n,
FT_Vector* coords,
FT_Pos delta_x,
FT_Pos delta_y )
{
FT_UInt k;
if ( delta_x )
for ( k = 0; k < n; k++ )
coords[k].x += delta_x;
if ( delta_y )
for ( k = 0; k < n; k++ )
coords[k].y += delta_y;
}
#undef IS_HINTED
#define IS_HINTED( flags ) ( ( flags & FT_LOAD_NO_HINTING ) == 0 )
/*************************************************************************/
/* */
/* The following functions are used by default with TrueType fonts. */
/* However, they can be replaced by alternatives if we need to support */
/* TrueType-compressed formats (like MicroType) in the future. */
/* */
/*************************************************************************/
FT_CALLBACK_DEF( FT_Error )
TT_Access_Glyph_Frame( TT_Loader loader,
FT_UInt glyph_index,
FT_ULong offset,
FT_UInt byte_count )
{
FT_Error error;
FT_Stream stream = loader->stream;
/* for non-debug mode */
FT_UNUSED( glyph_index );
FT_TRACE5(( "Glyph %ld\n", glyph_index ));
/* the following line sets the `error' variable through macros! */
if ( FT_STREAM_SEEK( offset ) || FT_FRAME_ENTER( byte_count ) )
return error;
loader->cursor = stream->cursor;
loader->limit = stream->limit;
return TT_Err_Ok;
}
FT_CALLBACK_DEF( void )
TT_Forget_Glyph_Frame( TT_Loader loader )
{
FT_Stream stream = loader->stream;
FT_FRAME_EXIT();
}
FT_CALLBACK_DEF( FT_Error )
TT_Load_Glyph_Header( TT_Loader loader )
{
FT_Byte* p = loader->cursor;
FT_Byte* limit = loader->limit;
if ( p + 10 > limit )
return TT_Err_Invalid_Outline;
loader->n_contours = FT_NEXT_SHORT( p );
loader->bbox.xMin = FT_NEXT_SHORT( p );
loader->bbox.yMin = FT_NEXT_SHORT( p );
loader->bbox.xMax = FT_NEXT_SHORT( p );
loader->bbox.yMax = FT_NEXT_SHORT( p );
FT_TRACE5(( " # of contours: %d\n", loader->n_contours ));
FT_TRACE5(( " xMin: %4d xMax: %4d\n", loader->bbox.xMin,
loader->bbox.xMax ));
FT_TRACE5(( " yMin: %4d yMax: %4d\n", loader->bbox.yMin,
loader->bbox.yMax ));
loader->cursor = p;
return TT_Err_Ok;
}
FT_CALLBACK_DEF( FT_Error )
TT_Load_Simple_Glyph( TT_Loader load )
{
FT_Error error;
FT_Byte* p = load->cursor;
FT_Byte* limit = load->limit;
FT_GlyphLoader gloader = load->gloader;
FT_Int n_contours = load->n_contours;
FT_Outline* outline;
TT_Face face = (TT_Face)load->face;
FT_UShort n_ins;
FT_Int n_points;
FT_Byte *flag, *flag_limit;
FT_Byte c, count;
FT_Vector *vec, *vec_limit;
FT_Pos x;
FT_Short *cont, *cont_limit;
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;
for ( ; cont < cont_limit; cont++ )
cont[0] = FT_NEXT_USHORT( p );
n_points = 0;
if ( n_contours > 0 )
{
n_points = cont[-1] + 1;
if ( n_points < 0 )
goto Invalid_Outline;
}
/* note that we will add four phantom points later */
error = FT_GLYPHLOADER_CHECK_POINTS( gloader, n_points + 4, 0 );
if ( error )
goto Fail;
/* we'd better check the contours table right now */
outline = &gloader->current.outline;
for ( cont = outline->contours + 1; cont < cont_limit; cont++ )
if ( cont[-1] >= cont[0] )
goto Invalid_Outline;
/* reading the bytecode instructions */
load->glyph->control_len = 0;
load->glyph->control_data = 0;
if ( p + 2 > limit )
goto Invalid_Outline;
n_ins = FT_NEXT_USHORT( p );
FT_TRACE5(( " Instructions size: %u\n", n_ins ));
if ( n_ins > face->max_profile.maxSizeOfInstructions )
{
FT_TRACE0(( "TT_Load_Simple_Glyph: Too many instructions (%d)\n",
n_ins ));
error = TT_Err_Too_Many_Hints;
goto Fail;
}
if ( ( limit - p ) < n_ins )
{
FT_TRACE0(( "TT_Load_Simple_Glyph: Instruction count mismatch!\n" ));
error = TT_Err_Too_Many_Hints;
goto Fail;
}
#ifdef TT_USE_BYTECODE_INTERPRETER
if ( IS_HINTED( load->load_flags ) )
{
load->glyph->control_len = n_ins;
load->glyph->control_data = load->exec->glyphIns;
FT_MEM_COPY( load->exec->glyphIns, p, (FT_Long)n_ins );
}
#endif /* TT_USE_BYTECODE_INTERPRETER */
p += n_ins;
/* reading the point tags */
flag = (FT_Byte*)outline->tags;
flag_limit = flag + n_points;
FT_ASSERT( flag != NULL );
while ( flag < flag_limit )
{
if ( p + 1 > limit )
goto Invalid_Outline;
*flag++ = c = FT_NEXT_BYTE( p );
if ( c & 8 )
{
if ( p + 1 > limit )
goto Invalid_Outline;
count = FT_NEXT_BYTE( p );
if ( flag + (FT_Int)count > flag_limit )
goto Invalid_Outline;
for ( ; count > 0; count-- )
*flag++ = c;
}
}
/* reading the X coordinates */
vec = outline->points;
vec_limit = vec + n_points;
flag = (FT_Byte*)outline->tags;
x = 0;
if ( p + xy_size > limit )
goto Invalid_Outline;
for ( ; vec < vec_limit; vec++, flag++ )
{
FT_Pos y = 0;
FT_Byte f = *flag;
if ( f & 2 )
{
if ( p + 1 > limit )
goto Invalid_Outline;
y = (FT_Pos)FT_NEXT_BYTE( p );
if ( ( f & 16 ) == 0 )
y = -y;
}
else if ( ( f & 16 ) == 0 )
{
if ( p + 2 > limit )
goto Invalid_Outline;
y = (FT_Pos)FT_NEXT_SHORT( p );
}
x += y;
vec->x = x;
*flag = f & ~( 2 | 16 );
}
/* reading the Y coordinates */
vec = gloader->current.outline.points;
vec_limit = vec + n_points;
flag = (FT_Byte*)outline->tags;
x = 0;
for ( ; vec < vec_limit; vec++, flag++ )
{
FT_Pos y = 0;
FT_Byte f = *flag;
if ( f & 4 )
{
if ( p + 1 > limit )
goto Invalid_Outline;
y = (FT_Pos)FT_NEXT_BYTE( p );
if ( ( f & 32 ) == 0 )
y = -y;
}
else if ( ( f & 32 ) == 0 )
{
if ( p + 2 > limit )
goto Invalid_Outline;
y = (FT_Pos)FT_NEXT_SHORT( p );
}
x += y;
vec->y = x;
*flag = f & ~( 4 | 32 );
}
outline->n_points = (FT_UShort)n_points;
outline->n_contours = (FT_Short) n_contours;
load->cursor = p;
Fail:
return error;
Invalid_Outline:
error = TT_Err_Invalid_Outline;
goto Fail;
}
FT_CALLBACK_DEF( FT_Error )
TT_Load_Composite_Glyph( TT_Loader loader )
{
FT_Error error;
FT_Byte* p = loader->cursor;
FT_Byte* limit = loader->limit;
FT_GlyphLoader gloader = loader->gloader;
FT_SubGlyph subglyph;
FT_UInt num_subglyphs;
num_subglyphs = 0;
do
{
FT_Fixed xx, xy, yy, yx;
FT_UInt count;
/* check that we can load a new subglyph */
error = FT_GlyphLoader_CheckSubGlyphs( gloader, num_subglyphs + 1 );
if ( error )
goto Fail;
/* check space */
if ( p + 4 > limit )
goto Invalid_Composite;
subglyph = gloader->current.subglyphs + num_subglyphs;
subglyph->arg1 = subglyph->arg2 = 0;
subglyph->flags = FT_NEXT_USHORT( p );
subglyph->index = FT_NEXT_USHORT( p );
/* check space */
count = 2;
if ( subglyph->flags & ARGS_ARE_WORDS )
count += 2;
if ( subglyph->flags & WE_HAVE_A_SCALE )
count += 2;
else if ( subglyph->flags & WE_HAVE_AN_XY_SCALE )
count += 4;
else if ( subglyph->flags & WE_HAVE_A_2X2 )
count += 8;
if ( p + count > limit )
goto Invalid_Composite;
/* read arguments */
if ( subglyph->flags & ARGS_ARE_WORDS )
{
subglyph->arg1 = FT_NEXT_SHORT( p );
subglyph->arg2 = FT_NEXT_SHORT( p );
}
else
{
subglyph->arg1 = FT_NEXT_CHAR( p );
subglyph->arg2 = FT_NEXT_CHAR( p );
}
/* read transform */
xx = yy = 0x10000L;
xy = yx = 0;
if ( subglyph->flags & WE_HAVE_A_SCALE )
{
xx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
yy = xx;
}
else if ( subglyph->flags & WE_HAVE_AN_XY_SCALE )
{
xx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
yy = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
}
else if ( subglyph->flags & WE_HAVE_A_2X2 )
{
xx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
yx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
xy = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
yy = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
}
subglyph->transform.xx = xx;
subglyph->transform.xy = xy;
subglyph->transform.yx = yx;
subglyph->transform.yy = yy;
num_subglyphs++;
} while ( subglyph->flags & MORE_COMPONENTS );
gloader->current.num_subglyphs = num_subglyphs;
#ifdef TT_USE_BYTECODE_INTERPRETER
{
FT_Stream stream = loader->stream;
/* we must undo the FT_FRAME_ENTER in order to point to the */
/* composite instructions, if we find some. */
/* we will process them later... */
/* */
loader->ins_pos = (FT_ULong)( FT_STREAM_POS() +
p - limit );
}
#endif
loader->cursor = p;
Fail:
return error;
Invalid_Composite:
error = TT_Err_Invalid_Composite;
goto Fail;
}
FT_LOCAL_DEF( void )
TT_Init_Glyph_Loading( TT_Face face )
{
face->access_glyph_frame = TT_Access_Glyph_Frame;
face->read_glyph_header = TT_Load_Glyph_Header;
face->read_simple_glyph = TT_Load_Simple_Glyph;
face->read_composite_glyph = TT_Load_Composite_Glyph;
face->forget_glyph_frame = TT_Forget_Glyph_Frame;
}
static void
tt_prepare_zone( TT_GlyphZone zone,
FT_GlyphLoad load,
FT_UInt start_point,
FT_UInt start_contour )
{
zone->n_points = (FT_UShort)( load->outline.n_points - start_point );
zone->n_contours = (FT_Short) ( load->outline.n_contours - start_contour );
zone->org = load->extra_points + start_point;
zone->cur = load->outline.points + start_point;
zone->orus = load->extra_points2 + start_point;
zone->tags = (FT_Byte*)load->outline.tags + start_point;
zone->contours = (FT_UShort*)load->outline.contours + start_contour;
zone->first_point = (FT_UShort)start_point;
}
/*************************************************************************/
/* */
/* <Function> */
/* TT_Hint_Glyph */
/* */
/* <Description> */
/* Hint the glyph using the zone prepared by the caller. Note that */
/* the zone is supposed to include four phantom points. */
/* */
static FT_Error
TT_Hint_Glyph( TT_Loader loader,
FT_Bool is_composite )
{
TT_GlyphZone zone = &loader->zone;
FT_Pos origin;
#ifdef TT_USE_BYTECODE_INTERPRETER
FT_UInt n_ins;
#else
FT_UNUSED( is_composite );
#endif
#ifdef TT_USE_BYTECODE_INTERPRETER
n_ins = loader->glyph->control_len;
#endif
origin = zone->cur[zone->n_points - 4].x;
origin = FT_PIX_ROUND( origin ) - origin;
if ( origin )
translate_array( zone->n_points, zone->cur, origin, 0 );
#ifdef TT_USE_BYTECODE_INTERPRETER
/* save original point position in org */
if ( n_ins > 0 )
FT_ARRAY_COPY( zone->org, zone->cur, zone->n_points );
#endif
/* round pp2 and pp4 */
zone->cur[zone->n_points - 3].x =
FT_PIX_ROUND( zone->cur[zone->n_points - 3].x );
zone->cur[zone->n_points - 1].y =
FT_PIX_ROUND( zone->cur[zone->n_points - 1].y );
#ifdef TT_USE_BYTECODE_INTERPRETER
if ( n_ins > 0 )
{
FT_Bool debug;
FT_Error error;
error = TT_Set_CodeRange( loader->exec, tt_coderange_glyph,
loader->exec->glyphIns, n_ins );
if ( error )
return error;
loader->exec->is_composite = is_composite;
loader->exec->pts = *zone;
debug = FT_BOOL( !( loader->load_flags & FT_LOAD_NO_SCALE ) &&
((TT_Size)loader->size)->debug );
error = TT_Run_Context( loader->exec, debug );
if ( error && loader->exec->pedantic_hinting )
return error;
}
#endif
/* save glyph phantom points */
if ( !loader->preserve_pps )
{
loader->pp1 = zone->cur[zone->n_points - 4];
loader->pp2 = zone->cur[zone->n_points - 3];
loader->pp3 = zone->cur[zone->n_points - 2];
loader->pp4 = zone->cur[zone->n_points - 1];
}
return TT_Err_Ok;
}
/*************************************************************************/
/* */
/* <Function> */
/* TT_Process_Simple_Glyph */
/* */
/* <Description> */
/* Once a simple glyph has been loaded, it needs to be processed. */
/* Usually, this means scaling and hinting through bytecode */
/* interpretation. */
/* */
static FT_Error
TT_Process_Simple_Glyph( TT_Loader loader )
{
FT_GlyphLoader gloader = loader->gloader;
FT_Error error = TT_Err_Ok;
FT_Outline* outline;
FT_UInt n_points;
outline = &gloader->current.outline;
n_points = outline->n_points;
/* set phantom points */
outline->points[n_points ] = loader->pp1;
outline->points[n_points + 1] = loader->pp2;
outline->points[n_points + 2] = loader->pp3;
outline->points[n_points + 3] = loader->pp4;
outline->tags[n_points ] = 0;
outline->tags[n_points + 1] = 0;
outline->tags[n_points + 2] = 0;
outline->tags[n_points + 3] = 0;
n_points += 4;
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
if ( ((TT_Face)loader->face)->doblend )
{
/* Deltas apply to the unscaled data. */
FT_Vector* deltas;
FT_Memory memory = loader->face->memory;
FT_UInt i;
error = TT_Vary_Get_Glyph_Deltas( (TT_Face)(loader->face),
loader->glyph_index,
&deltas,
n_points );
if ( error )
return error;
for ( i = 0; i < n_points; ++i )
{
outline->points[i].x += deltas[i].x;
outline->points[i].y += deltas[i].y;
}
FT_FREE( deltas );
}
#endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */
if ( IS_HINTED( loader->load_flags ) )
{
tt_prepare_zone( &loader->zone, &gloader->current, 0, 0 );
FT_ARRAY_COPY( loader->zone.orus, loader->zone.cur,
loader->zone.n_points + 4 );
}
/* scale the glyph */
if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
{
FT_Vector* vec = outline->points;
FT_Vector* limit = outline->points + n_points;
FT_Fixed x_scale = ((TT_Size)loader->size)->metrics.x_scale;
FT_Fixed y_scale = ((TT_Size)loader->size)->metrics.y_scale;
for ( ; vec < limit; vec++ )
{
vec->x = FT_MulFix( vec->x, x_scale );
vec->y = FT_MulFix( vec->y, y_scale );
}
loader->pp1 = outline->points[n_points - 4];
loader->pp2 = outline->points[n_points - 3];
loader->pp3 = outline->points[n_points - 2];
loader->pp4 = outline->points[n_points - 1];
}
if ( IS_HINTED( loader->load_flags ) )
{
loader->zone.n_points += 4;
error = TT_Hint_Glyph( loader, 0 );
}
return error;
}
/*************************************************************************/
/* */
/* <Function> */
/* TT_Process_Composite_Component */
/* */
/* <Description> */
/* Once a composite component has been loaded, it needs to be */
/* processed. Usually, this means transforming and translating. */
/* */
static FT_Error
TT_Process_Composite_Component( TT_Loader loader,
FT_SubGlyph subglyph,
FT_UInt start_point,
FT_UInt num_base_points )
{
FT_GlyphLoader gloader = loader->gloader;
FT_Vector* base_vec = gloader->base.outline.points;
FT_UInt num_points = gloader->base.outline.n_points;
FT_Bool have_scale;
FT_Pos x, y;
have_scale = FT_BOOL( subglyph->flags & ( WE_HAVE_A_SCALE |
WE_HAVE_AN_XY_SCALE |
WE_HAVE_A_2X2 ) );
/* perform the transform required for this subglyph */
if ( have_scale )
{
FT_UInt i;
for ( i = num_base_points; i < num_points; i++ )
FT_Vector_Transform( base_vec + i, &subglyph->transform );
}
/* get offset */
if ( !( subglyph->flags & ARGS_ARE_XY_VALUES ) )
{
FT_UInt k = subglyph->arg1;
FT_UInt l = subglyph->arg2;
FT_Vector* p1;
FT_Vector* p2;
/* match l-th point of the newly loaded component to the k-th point */
/* of the previously loaded components. */
/* change to the point numbers used by our outline */
k += start_point;
l += num_base_points;
if ( k >= num_base_points ||
l >= num_points )
return TT_Err_Invalid_Composite;
p1 = gloader->base.outline.points + k;
p2 = gloader->base.outline.points + l;
x = p1->x - p2->x;
y = p1->y - p2->y;
}
else
{
x = subglyph->arg1;
y = subglyph->arg2;
if ( !x && !y )
return TT_Err_Ok;
/* Use a default value dependent on */
/* TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED. This is useful for old TT */
/* fonts which don't set the xxx_COMPONENT_OFFSET bit. */
if ( have_scale &&
#ifdef TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED
!( subglyph->flags & UNSCALED_COMPONENT_OFFSET ) )
#else
( subglyph->flags & SCALED_COMPONENT_OFFSET ) )
#endif
{
#if 0
/*************************************************************************/
/* */
/* This algorithm is what Apple documents. But it doesn't work. */
/* */
int a = subglyph->transform.xx > 0 ? subglyph->transform.xx
: -subglyph->transform.xx;
int b = subglyph->transform.yx > 0 ? subglyph->transform.yx
: -subglyph->transform.yx;
int c = subglyph->transform.xy > 0 ? subglyph->transform.xy
: -subglyph->transform.xy;
int d = subglyph->transform.yy > 0 ? subglyph->transform.yy
: -subglyph->transform.yy;
int m = a > b ? a : b;
int n = c > d ? c : d;
if ( a - b <= 33 && a - b >= -33 )
m *= 2;
if ( c - d <= 33 && c - d >= -33 )
n *= 2;
x = FT_MulFix( x, m );
y = FT_MulFix( y, n );
#else /* 0 */
/*************************************************************************/
/* */
/* This algorithm is a guess and works much better than the above. */
/* */
FT_Fixed mac_xscale = FT_SqrtFixed(
FT_MulFix( subglyph->transform.xx,
subglyph->transform.xx ) +
FT_MulFix( subglyph->transform.xy,
subglyph->transform.xy ) );
FT_Fixed mac_yscale = FT_SqrtFixed(
FT_MulFix( subglyph->transform.yy,
subglyph->transform.yy ) +
FT_MulFix( subglyph->transform.yx,
subglyph->transform.yx ) );
x = FT_MulFix( x, mac_xscale );
y = FT_MulFix( y, mac_yscale );
#endif /* 0 */
}
if ( !( loader->load_flags & FT_LOAD_NO_SCALE ) )
{
FT_Fixed x_scale = ((TT_Size)loader->size)->metrics.x_scale;
FT_Fixed y_scale = ((TT_Size)loader->size)->metrics.y_scale;
x = FT_MulFix( x, x_scale );
y = FT_MulFix( y, y_scale );
if ( subglyph->flags & ROUND_XY_TO_GRID )
{
x = FT_PIX_ROUND( x );
y = FT_PIX_ROUND( y );
}
}
}
if ( x || y )
translate_array( num_points - num_base_points,
base_vec + num_base_points,
x, y );
return TT_Err_Ok;
}
/*************************************************************************/
/* */
/* <Function> */
/* TT_Process_Composite_Glyph */
/* */
/* <Description> */
/* This is slightly different from TT_Process_Simple_Glyph, in that */
/* its sole purpose is to hint the glyph. Thus this function is */
/* only available when bytecode interpreter is enabled. */
/* */
static FT_Error
TT_Process_Composite_Glyph( TT_Loader loader,
FT_UInt start_point,
FT_UInt start_contour )
{
FT_Error error;
FT_Outline* outline;
FT_UInt i;
outline = &loader->gloader->base.outline;
/* make room for phantom points */
error = FT_GLYPHLOADER_CHECK_POINTS( loader->gloader,
outline->n_points + 4,
0 );
if ( error )
return error;
outline->points[outline->n_points ] = loader->pp1;
outline->points[outline->n_points + 1] = loader->pp2;
outline->points[outline->n_points + 2] = loader->pp3;
outline->points[outline->n_points + 3] = loader->pp4;
outline->tags[outline->n_points ] = 0;
outline->tags[outline->n_points + 1] = 0;
outline->tags[outline->n_points + 2] = 0;
outline->tags[outline->n_points + 3] = 0;
#ifdef TT_USE_BYTECODE_INTERPRETER
{
FT_Stream stream = loader->stream;
FT_UShort n_ins;
/* 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 */
if ( n_ins > ((TT_Face)loader->face)->max_profile.maxSizeOfInstructions )
{
FT_TRACE0(( "TT_Process_Composite_Glyph: Too many instructions (%d)\n",
n_ins ));
return TT_Err_Too_Many_Hints;
}
else if ( n_ins == 0 )
return TT_Err_Ok;
if ( FT_STREAM_READ( loader->exec->glyphIns, n_ins ) )
return error;
loader->glyph->control_data = loader->exec->glyphIns;
loader->glyph->control_len = n_ins;
}
#endif
tt_prepare_zone( &loader->zone, &loader->gloader->base,
start_point, start_contour );
/* Some points are likely touched during execution of */
/* instructions on components. So let's untouch them. */
for ( i = start_point; i < loader->zone.n_points; i++ )
loader->zone.tags[i] &= ~( FT_CURVE_TAG_TOUCH_X |
FT_CURVE_TAG_TOUCH_Y );
loader->zone.n_points += 4;
return TT_Hint_Glyph( loader, 1 );
}
/* Calculate the four phantom points. */
/* The first two stand for horizontal origin and advance. */
/* The last two stand for vertical origin and advance. */
#define TT_LOADER_SET_PP( loader ) \
do { \
(loader)->pp1.x = (loader)->bbox.xMin - (loader)->left_bearing; \
(loader)->pp1.y = 0; \
(loader)->pp2.x = (loader)->pp1.x + (loader)->advance; \
(loader)->pp2.y = 0; \
(loader)->pp3.x = 0; \
(loader)->pp3.y = (loader)->top_bearing + (loader)->bbox.yMax; \
(loader)->pp4.x = 0; \
(loader)->pp4.y = (loader)->pp3.y - (loader)->vadvance; \
} while ( 0 )
/*************************************************************************/
/* */
/* <Function> */
/* load_truetype_glyph */
/* */
/* <Description> */
/* Loads a given truetype glyph. Handles composites and uses a */
/* TT_Loader object. */
/* */
static FT_Error
load_truetype_glyph( TT_Loader loader,
FT_UInt glyph_index,
FT_UInt recurse_count )
{
FT_Error error;
FT_Fixed x_scale, y_scale;
FT_ULong offset;
TT_Face face = (TT_Face)loader->face;
FT_GlyphLoader gloader = loader->gloader;
FT_Bool opened_frame = 0;
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
FT_Vector* deltas = NULL;
#endif
#ifdef FT_CONFIG_OPTION_INCREMENTAL
FT_StreamRec inc_stream;
FT_Data glyph_data;
FT_Bool glyph_data_loaded = 0;
#endif
if ( recurse_count > face->max_profile.maxComponentDepth )
{
error = TT_Err_Invalid_Composite;
goto Exit;
}
/* check glyph index */
if ( glyph_index >= (FT_UInt)face->root.num_glyphs )
{
error = TT_Err_Invalid_Glyph_Index;
goto Exit;
}
loader->glyph_index = glyph_index;
if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
{
x_scale = ((TT_Size)loader->size)->metrics.x_scale;
y_scale = ((TT_Size)loader->size)->metrics.y_scale;
}
else
{
x_scale = 0x10000L;
y_scale = 0x10000L;
}
/* get metrics, horizontal and vertical */
{
FT_Short left_bearing = 0, top_bearing = 0;
FT_UShort advance_width = 0, advance_height = 0;
Get_HMetrics( face, glyph_index,
(FT_Bool)!( loader->load_flags &
FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH ),
&left_bearing,
&advance_width );
Get_VMetrics( face, glyph_index,
(FT_Bool)!( loader->load_flags &
FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH ),
&top_bearing,
&advance_height );
#ifdef FT_CONFIG_OPTION_INCREMENTAL
/* If this is an incrementally loaded font see if there are */
/* overriding metrics for this glyph. */
if ( face->root.internal->incremental_interface &&
face->root.internal->incremental_interface->funcs->get_glyph_metrics )
{
FT_Incremental_MetricsRec metrics;
metrics.bearing_x = left_bearing;
metrics.bearing_y = 0;
metrics.advance = advance_width;
error = face->root.internal->incremental_interface->funcs->get_glyph_metrics(
face->root.internal->incremental_interface->object,
glyph_index, FALSE, &metrics );
if ( error )
goto Exit;
left_bearing = (FT_Short)metrics.bearing_x;
advance_width = (FT_UShort)metrics.advance;
#if 0
/* GWW: Do I do the same for vertical metrics? */
metrics.bearing_x = 0;
metrics.bearing_y = top_bearing;
metrics.advance = advance_height;
error = face->root.internal->incremental_interface->funcs->get_glyph_metrics(
face->root.internal->incremental_interface->object,
glyph_index, TRUE, &metrics );
if ( error )
goto Exit;
top_bearing = (FT_Short)metrics.bearing_y;
advance_height = (FT_UShort)metrics.advance;
#endif /* 0 */
}
#endif /* FT_CONFIG_OPTION_INCREMENTAL */
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;
}
}
/* Set `offset' to the start of the glyph relative to the start of */
/* the `glyf' table, and `byte_len' to the length of the glyph in */
/* bytes. */
#ifdef FT_CONFIG_OPTION_INCREMENTAL
/* If we are loading glyph data via the incremental interface, set */
/* the loader stream to a memory stream reading the data returned */
/* by the interface. */
if ( face->root.internal->incremental_interface )
{
error = face->root.internal->incremental_interface->funcs->get_glyph_data(
face->root.internal->incremental_interface->object,
glyph_index, &glyph_data );
if ( error )
goto Exit;
glyph_data_loaded = 1;
offset = 0;
loader->byte_len = glyph_data.length;
FT_MEM_ZERO( &inc_stream, sizeof ( inc_stream ) );
FT_Stream_OpenMemory( &inc_stream,
glyph_data.pointer, glyph_data.length );
loader->stream = &inc_stream;
}
else
#endif /* FT_CONFIG_OPTION_INCREMENTAL */
offset = tt_face_get_location( face, glyph_index,
(FT_UInt*)&loader->byte_len );
if ( loader->byte_len == 0 )
{
/* as described by Frederic Loyer, these are spaces or */
/* the unknown glyph. */
loader->bbox.xMin = 0;
loader->bbox.xMax = 0;
loader->bbox.yMin = 0;
loader->bbox.yMax = 0;
TT_LOADER_SET_PP( loader );
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
if ( ((TT_Face)(loader->face))->doblend )
{
/* this must be done before scaling */
FT_Memory memory = loader->face->memory;
error = TT_Vary_Get_Glyph_Deltas( (TT_Face)(loader->face),
glyph_index, &deltas, 4 );
if ( error )
goto Exit;
loader->pp1.x += deltas[0].x; loader->pp1.y += deltas[0].y;
loader->pp2.x += deltas[1].x; loader->pp2.y += deltas[1].y;
loader->pp3.x += deltas[2].x; loader->pp3.y += deltas[2].y;
loader->pp4.x += deltas[3].x; loader->pp4.y += deltas[3].y;
FT_FREE( deltas );
}
#endif
if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
{
loader->pp1.x = FT_MulFix( loader->pp1.x, x_scale );
loader->pp2.x = FT_MulFix( loader->pp2.x, x_scale );
loader->pp3.y = FT_MulFix( loader->pp3.y, y_scale );
loader->pp4.y = FT_MulFix( loader->pp4.y, y_scale );
}
error = TT_Err_Ok;
goto Exit;
}
error = face->access_glyph_frame( loader, glyph_index,
loader->glyf_offset + offset,
loader->byte_len );
if ( error )
goto Exit;
opened_frame = 1;
/* read first glyph header */
error = face->read_glyph_header( loader );
if ( error )
goto Exit;
TT_LOADER_SET_PP( loader );
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
/* if it is a simple glyph, load it */
if ( loader->n_contours >= 0 )
{
error = face->read_simple_glyph( loader );
if ( error )
goto Exit;
/* all data have been read */
face->forget_glyph_frame( loader );
opened_frame = 0;
error = TT_Process_Simple_Glyph( loader );
if ( error )
goto Exit;
FT_GlyphLoader_Add( gloader );
}
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
/* otherwise, load a composite! */
else if ( loader->n_contours == -1 )
{
FT_UInt start_point;
FT_UInt start_contour;
FT_ULong ins_pos; /* position of composite instructions, if any */
start_point = gloader->base.outline.n_points;
start_contour = gloader->base.outline.n_contours;
/* for each subglyph, read composite header */
error = face->read_composite_glyph( loader );
if ( error )
goto Exit;
/* store the offset of instructions */
ins_pos = loader->ins_pos;
/* all data we need are read */
face->forget_glyph_frame( loader );
opened_frame = 0;
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
if ( face->doblend )
{
FT_Int i, limit;
FT_SubGlyph subglyph;
FT_Memory memory = face->root.memory;
/* this provides additional offsets */
/* for each component's translation */
if ( (error = TT_Vary_Get_Glyph_Deltas(
face,
glyph_index,
&deltas,
gloader->current.num_subglyphs + 4 )) != 0 )
goto Exit;
subglyph = gloader->current.subglyphs + gloader->base.num_subglyphs;
limit = gloader->current.num_subglyphs;
for ( i = 0; i < limit; ++i, ++subglyph )
{
if ( subglyph->flags & ARGS_ARE_XY_VALUES )
{
subglyph->arg1 += deltas[i].x;
subglyph->arg2 += deltas[i].y;
}
}
loader->pp1.x += deltas[i + 0].x; loader->pp1.y += deltas[i + 0].y;
loader->pp2.x += deltas[i + 1].x; loader->pp2.y += deltas[i + 1].y;
loader->pp3.x += deltas[i + 2].x; loader->pp3.y += deltas[i + 2].y;
loader->pp4.x += deltas[i + 3].x; loader->pp4.y += deltas[i + 3].y;
FT_FREE( deltas );
}
#endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */
if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
{
loader->pp1.x = FT_MulFix( loader->pp1.x, x_scale );
loader->pp2.x = FT_MulFix( loader->pp2.x, x_scale );
loader->pp3.y = FT_MulFix( loader->pp3.y, y_scale );
loader->pp4.y = FT_MulFix( loader->pp4.y, y_scale );
}
/* if the flag FT_LOAD_NO_RECURSE is set, we return the subglyph */
/* `as is' in the glyph slot (the client application will be */
/* responsible for interpreting these data)... */
if ( loader->load_flags & FT_LOAD_NO_RECURSE )
{
FT_GlyphLoader_Add( gloader );
loader->glyph->format = FT_GLYPH_FORMAT_COMPOSITE;
goto Exit;
}
/*********************************************************************/
/*********************************************************************/
/*********************************************************************/
{
FT_UInt n, num_base_points;
FT_SubGlyph subglyph = 0;
FT_UInt num_points = start_point;
FT_UInt num_subglyphs = gloader->current.num_subglyphs;
FT_UInt num_base_subgs = gloader->base.num_subglyphs;
FT_Stream old_stream = loader->stream;
TT_GraphicsState saved_GS;
if ( loader->exec )
saved_GS = loader->exec->GS;
FT_GlyphLoader_Add( gloader );
/* read each subglyph independently */
for ( n = 0; n < num_subglyphs; n++ )
{
FT_Vector pp[4];
/* reinitialize graphics state */
if ( loader->exec )
loader->exec->GS = saved_GS;
/* Each time we call load_truetype_glyph in this loop, the */
/* value of `gloader.base.subglyphs' can change due to table */
/* reallocations. We thus need to recompute the subglyph */
/* pointer on each iteration. */
subglyph = gloader->base.subglyphs + num_base_subgs + n;
pp[0] = loader->pp1;
pp[1] = loader->pp2;
pp[2] = loader->pp3;
pp[3] = loader->pp4;
num_base_points = gloader->base.outline.n_points;
error = load_truetype_glyph( loader, subglyph->index,
recurse_count + 1 );
if ( error )
goto Exit;
/* restore subglyph pointer */
subglyph = gloader->base.subglyphs + num_base_subgs + n;
if ( !( subglyph->flags & USE_MY_METRICS ) )
{
loader->pp1 = pp[0];
loader->pp2 = pp[1];
loader->pp3 = pp[2];
loader->pp4 = pp[3];
}
num_points = gloader->base.outline.n_points;
if ( num_points == num_base_points )
continue;
/* gloader->base.outline consists of three parts: */
/* 0 -(1)-> start_point -(2)-> num_base_points -(3)-> n_points. */
/* */
/* (1): exists from the beginning */
/* (2): components that have been loaded so far */
/* (3): the newly loaded component */
TT_Process_Composite_Component( loader, subglyph, start_point,
num_base_points );
}
loader->stream = old_stream;
/* process the glyph */
loader->ins_pos = ins_pos;
if ( IS_HINTED( loader->load_flags ) &&
#ifdef TT_USE_BYTECODE_INTERPRETER
subglyph->flags & WE_HAVE_INSTR &&
#endif
num_points > start_point )
TT_Process_Composite_Glyph( loader, start_point, start_contour );
}
}
else
{
/* invalid composite count (negative but not -1) */
error = TT_Err_Invalid_Outline;
goto Exit;
}
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
Exit:
if ( opened_frame )
face->forget_glyph_frame( loader );
#ifdef FT_CONFIG_OPTION_INCREMENTAL
if ( glyph_data_loaded )
face->root.internal->incremental_interface->funcs->free_glyph_data(
face->root.internal->incremental_interface->object,
&glyph_data );
#endif
return error;
}
static FT_Error
compute_glyph_metrics( TT_Loader loader,
FT_UInt glyph_index )
{
FT_BBox bbox;
TT_Face face = (TT_Face)loader->face;
FT_Fixed y_scale;
TT_GlyphSlot glyph = loader->glyph;
TT_Size size = (TT_Size)loader->size;
y_scale = 0x10000L;
if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
y_scale = size->root.metrics.y_scale;
if ( glyph->format != FT_GLYPH_FORMAT_COMPOSITE )
FT_Outline_Get_CBox( &glyph->outline, &bbox );
else
bbox = loader->bbox;
/* get the device-independent horizontal advance; it is scaled later */
/* by the base layer. */
{
FT_Pos advance = loader->linear;
/* the flag FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH was introduced to */
/* correctly support DynaLab fonts, which have an incorrect */
/* `advance_Width_Max' field! It is used, to my knowledge, */
/* exclusively in the X-TrueType font server. */
/* */
if ( face->postscript.isFixedPitch &&
( loader->load_flags & FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH ) == 0 )
advance = face->horizontal.advance_Width_Max;
/* we need to return the advance in font units in linearHoriAdvance, */
/* it will be scaled later by the base layer. */
glyph->linearHoriAdvance = advance;
}
glyph->metrics.horiBearingX = bbox.xMin;
glyph->metrics.horiBearingY = bbox.yMax;
glyph->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
/* Now take care of vertical metrics. In the case where there is */
/* no vertical information within the font (relatively common), make */
/* up some metrics by `hand'... */
{
FT_Pos top; /* scaled vertical top side bearing */
FT_Pos advance; /* scaled vertical advance height */
/* Get the unscaled top bearing and advance height. */
if ( face->vertical_info &&
face->vertical.number_Of_VMetrics > 0 )
{
top = (FT_Short)FT_DivFix( loader->pp3.y - bbox.yMax,
y_scale );
if ( loader->pp3.y <= loader->pp4.y )
advance = 0;
else
advance = (FT_UShort)FT_DivFix( loader->pp3.y - loader->pp4.y,
y_scale );
}
else
{
FT_Pos height;
/* XXX Compute top side bearing and advance height in */
/* Get_VMetrics instead of here. */
/* NOTE: The OS/2 values are the only `portable' ones, */
/* which is why we use them, if there is an OS/2 */
/* table in the font. Otherwise, we use the */
/* values defined in the horizontal header. */
height = (FT_Short)FT_DivFix( bbox.yMax - bbox.yMin,
y_scale );
if ( face->os2.version != 0xFFFFU )
advance = (FT_Pos)( face->os2.sTypoAscender -
face->os2.sTypoDescender );
else
advance = (FT_Pos)( face->horizontal.Ascender -
face->horizontal.Descender );
top = ( advance - height ) / 2;
}
#ifdef FT_CONFIG_OPTION_INCREMENTAL
{
FT_Incremental_InterfaceRec* incr;
FT_Incremental_MetricsRec metrics;
FT_Error error;
incr = face->root.internal->incremental_interface;
/* If this is an incrementally loaded font see if there are */
/* overriding metrics for this glyph. */
if ( incr && incr->funcs->get_glyph_metrics )
{
metrics.bearing_x = 0;
metrics.bearing_y = top;
metrics.advance = advance;
error = incr->funcs->get_glyph_metrics( incr->object,
glyph_index,
TRUE,
&metrics );
if ( error )
return error;
top = metrics.bearing_y;
advance = metrics.advance;
}
}
/* GWW: Do vertical metrics get loaded incrementally too? */
#endif /* FT_CONFIG_OPTION_INCREMENTAL */
glyph->linearVertAdvance = advance;
/* scale the metrics */
if ( !( loader->load_flags & FT_LOAD_NO_SCALE ) )
{
top = FT_MulFix( top, y_scale );
advance = FT_MulFix( advance, y_scale );
}
/* XXX: for now, we have no better algorithm for the lsb, but it */
/* should work fine. */
/* */
glyph->metrics.vertBearingX = ( bbox.xMin - bbox.xMax ) / 2;
glyph->metrics.vertBearingY = top;
glyph->metrics.vertAdvance = advance;
}
/* adjust advance width to the value contained in the hdmx table */
if ( !face->postscript.isFixedPitch &&
IS_HINTED( loader->load_flags ) )
{
FT_Byte* widthp;
widthp = tt_face_get_device_metrics( face,
size->root.metrics.x_ppem,
glyph_index );
if ( widthp )
glyph->metrics.horiAdvance = *widthp << 6;
}
/* set glyph dimensions */
glyph->metrics.width = bbox.xMax - bbox.xMin;
glyph->metrics.height = bbox.yMax - bbox.yMin;
return 0;
}
#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
static FT_Error
load_sbit_image( TT_Size size,
TT_GlyphSlot glyph,
FT_UInt glyph_index,
FT_Int32 load_flags )
{
TT_Face face;
SFNT_Service sfnt;
FT_Stream stream;
FT_Error error;
TT_SBit_MetricsRec metrics;
face = (TT_Face)glyph->face;
sfnt = (SFNT_Service)face->sfnt;
stream = face->root.stream;
error = sfnt->load_sbit_image( face,
size->strike_index,
glyph_index,
(FT_Int)load_flags,
stream,
&glyph->bitmap,
&metrics );
if ( !error )
{
glyph->outline.n_points = 0;
glyph->outline.n_contours = 0;
glyph->metrics.width = (FT_Pos)metrics.width << 6;
glyph->metrics.height = (FT_Pos)metrics.height << 6;
glyph->metrics.horiBearingX = (FT_Pos)metrics.horiBearingX << 6;
glyph->metrics.horiBearingY = (FT_Pos)metrics.horiBearingY << 6;
glyph->metrics.horiAdvance = (FT_Pos)metrics.horiAdvance << 6;
glyph->metrics.vertBearingX = (FT_Pos)metrics.vertBearingX << 6;
glyph->metrics.vertBearingY = (FT_Pos)metrics.vertBearingY << 6;
glyph->metrics.vertAdvance = (FT_Pos)metrics.vertAdvance << 6;
glyph->format = FT_GLYPH_FORMAT_BITMAP;
if ( load_flags & FT_LOAD_VERTICAL_LAYOUT )
{
glyph->bitmap_left = metrics.vertBearingX;
glyph->bitmap_top = metrics.vertBearingY;
}
else
{
glyph->bitmap_left = metrics.horiBearingX;
glyph->bitmap_top = metrics.horiBearingY;
}
}
return error;
}
#endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
static FT_Error
tt_loader_init( TT_Loader loader,
TT_Size size,
TT_GlyphSlot glyph,
FT_Int32 load_flags )
{
TT_Face face;
FT_Stream stream;
face = (TT_Face)glyph->face;
stream = face->root.stream;
FT_MEM_ZERO( loader, sizeof ( TT_LoaderRec ) );
#ifdef TT_USE_BYTECODE_INTERPRETER
/* load execution context */
if ( IS_HINTED( load_flags ) )
{
TT_ExecContext exec;
FT_Bool grayscale;
if ( !size->cvt_ready )
{
FT_Error error = tt_size_ready_bytecode( size );
if ( error )
return error;
}
/* query new execution context */
exec = size->debug ? size->context
: ( (TT_Driver)FT_FACE_DRIVER( face ) )->context;
if ( !exec )
return TT_Err_Could_Not_Find_Context;
grayscale =
FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) != FT_RENDER_MODE_MONO );
TT_Load_Context( exec, face, size );
/* a change from mono to grayscale rendering (and vice versa) */
/* requires a re-execution of the CVT program */
if ( grayscale != exec->grayscale )
{
FT_UInt i;
exec->grayscale = grayscale;
for ( i = 0; i < size->cvt_size; i++ )
size->cvt[i] = FT_MulFix( face->cvt[i], size->ttmetrics.scale );
tt_size_run_prep( size );
}
/* see whether the cvt program has disabled hinting */
if ( exec->GS.instruct_control & 1 )
load_flags |= FT_LOAD_NO_HINTING;
/* load default graphics state -- if needed */
if ( exec->GS.instruct_control & 2 )
exec->GS = tt_default_graphics_state;
exec->pedantic_hinting = FT_BOOL( load_flags & FT_LOAD_PEDANTIC );
loader->exec = exec;
loader->instructions = exec->glyphIns;
}
#endif /* TT_USE_BYTECODE_INTERPRETER */
/* seek to the beginning of the glyph table -- for Type 42 fonts */
/* the table might be accessed from a Postscript stream or something */
/* else... */
#ifdef FT_CONFIG_OPTION_INCREMENTAL
if ( face->root.internal->incremental_interface )
loader->glyf_offset = 0;
else
#endif
{
FT_Error error = face->goto_table( face, TTAG_glyf, stream, 0 );
if ( error )
{
FT_ERROR(( "TT_Load_Glyph: could not access glyph table\n" ));
return error;
}
loader->glyf_offset = FT_STREAM_POS();
}
/* get face's glyph loader */
{
FT_GlyphLoader gloader = glyph->internal->loader;
FT_GlyphLoader_Rewind( gloader );
loader->gloader = gloader;
}
loader->load_flags = load_flags;
loader->face = (FT_Face)face;
loader->size = (FT_Size)size;
loader->glyph = (FT_GlyphSlot)glyph;
loader->stream = stream;
return TT_Err_Ok;
}
/*************************************************************************/
/* */
/* <Function> */
/* TT_Load_Glyph */
/* */
/* <Description> */
/* A function used to load a single glyph within a given glyph slot, */
/* for a given size. */
/* */
/* <Input> */
/* glyph :: A handle to a target slot object where the glyph */
/* will be loaded. */
/* */
/* size :: A handle to the source face size at which the glyph */
/* must be scaled/loaded. */
/* */
/* glyph_index :: The index of the glyph in the font file. */
/* */
/* load_flags :: A flag indicating what to load for this glyph. The */
/* FT_LOAD_XXX constants can be used to control the */
/* glyph loading process (e.g., whether the outline */
/* should be scaled, whether to load bitmaps or not, */
/* whether to hint the outline, etc). */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
FT_LOCAL_DEF( FT_Error )
TT_Load_Glyph( TT_Size size,
TT_GlyphSlot glyph,
FT_UInt glyph_index,
FT_Int32 load_flags )
{
TT_Face face;
FT_Error error;
TT_LoaderRec loader;
face = (TT_Face)glyph->face;
error = TT_Err_Ok;
#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
/* try to load embedded bitmap if any */
/* */
/* XXX: The convention should be emphasized in */
/* the documents because it can be confusing. */
if ( size->strike_index != 0xFFFFFFFFUL &&
( load_flags & FT_LOAD_NO_BITMAP ) == 0 )
{
error = load_sbit_image( size, glyph, glyph_index, load_flags );
if ( !error )
return TT_Err_Ok;
}
#endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
/* if FT_LOAD_NO_SCALE is not set, `ttmetrics' must be valid */
if ( !( load_flags & FT_LOAD_NO_SCALE ) && !size->ttmetrics.valid )
return TT_Err_Invalid_Size_Handle;
if ( load_flags & FT_LOAD_SBITS_ONLY )
return TT_Err_Invalid_Argument;
error = tt_loader_init( &loader, size, glyph, load_flags );
if ( error )
return error;
glyph->format = FT_GLYPH_FORMAT_OUTLINE;
glyph->num_subglyphs = 0;
glyph->outline.flags = 0;
/* main loading loop */
error = load_truetype_glyph( &loader, glyph_index, 0 );
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;
/* In case bit 1 of the `flags' field in the `head' table isn't */
/* set, translate array so that (0,0) is the glyph's origin. */
if ( ( face->header.Flags & 2 ) == 0 && loader.pp1.x )
FT_Outline_Translate( &glyph->outline, -loader.pp1.x, 0 );
}
compute_glyph_metrics( &loader, glyph_index );
}
/* Set the `high precision' bit flag. */
/* This is _critical_ to get correct output for monochrome */
/* TrueType glyphs at all sizes using the bytecode interpreter. */
/* */
if ( !( load_flags & FT_LOAD_NO_SCALE ) &&
size->root.metrics.y_ppem < 24 )
glyph->outline.flags |= FT_OUTLINE_HIGH_PRECISION;
return error;
}
/* END */