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baed3dd044
freetype/src/truetype/ttgload.c
Werner Lemberg baed3dd044 Oops! Undo private change.
2005-07-13 06:58:13 +00:00

2112 lines
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/***************************************************************************/
/* */
/* ttgload.c */
/* */
/* TrueType Glyph Loader (body). */
/* */
/* Copyright 1996-2001, 2002, 2003, 2004, 2005 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
/* Maximum recursion depth we allow for composite glyphs.
* The TrueType spec doesn't say anything about recursion,
* so it isn't clear that recursion is allowed at all. But
* we'll be generous.
*/
#define TT_MAX_COMPOSITE_RECURSE 5
/*************************************************************************/
/* */
/* <Function> */
/* tt_face_get_metrics */
/* */
/* <Description> */
/* Returns the horizontal or vertical metrics in font units for a */
/* given glyph. The metrics are the left side bearing (resp. top */
/* side bearing) and advance width (resp. advance height). */
/* */
/* <Input> */
/* header :: A pointer to either the horizontal or vertical metrics */
/* structure. */
/* */
/* idx :: The glyph index. */
/* */
/* <Output> */
/* bearing :: The bearing, either left side or top side. */
/* */
/* advance :: The advance width resp. advance height. */
/* */
/* <Note> */
/* This function will much probably move to another component in the */
/* near future, but I haven't decided which yet. */
/* */
#ifdef FT_OPTIMIZE_MEMORY
static void
tt_face_get_metrics( TT_Face face,
FT_Bool vertical,
FT_UInt idx,
FT_Short *abearing,
FT_UShort *aadvance )
{
TT_HoriHeader* header;
FT_Byte* p;
FT_Byte* limit;
FT_UShort k;
if ( vertical )
{
header = (TT_HoriHeader*)&face->vertical;
p = face->vert_metrics;
limit = p + face->vert_metrics_size;
}
else
{
header = &face->horizontal;
p = face->horz_metrics;
limit = p + face->horz_metrics_size;
}
k = header->number_Of_HMetrics;
if ( k > 0 )
{
if ( idx < (FT_UInt)k )
{
p += 4 * idx;
if ( p + 4 > limit )
goto NoData;
*aadvance = FT_NEXT_USHORT( p );
*abearing = FT_NEXT_SHORT( p );
}
else
{
p += 4 * ( k - 1 );
if ( p + 4 > limit )
goto NoData;
*aadvance = FT_NEXT_USHORT( p );
p += 2 + 2 * ( idx - k );
if ( p + 2 > limit )
*abearing = 0;
else
*abearing = FT_PEEK_SHORT( p );
}
}
else
{
NoData:
*abearing = 0;
*aadvance = 0;
}
}
#else /* !FT_OPTIMIZE_MEMORY */
static void
tt_face_get_metrics( TT_Face face,
FT_Bool vertical,
FT_UInt idx,
FT_Short *abearing,
FT_UShort *aadvance )
{
TT_HoriHeader* header = vertical ? (TT_HoriHeader*)&face->vertical
: &face->horizontal;
TT_LongMetrics longs_m;
FT_UShort k = header->number_Of_HMetrics;
if ( k == 0 )
{
*abearing = *aadvance = 0;
return;
}
if ( idx < (FT_UInt)k )
{
longs_m = (TT_LongMetrics)header->long_metrics + idx;
*abearing = longs_m->bearing;
*aadvance = longs_m->advance;
}
else
{
*abearing = ((TT_ShortMetrics*)header->short_metrics)[idx - k];
*aadvance = ((TT_LongMetrics)header->long_metrics)[k - 1].advance;
}
}
#endif /* !FT_OPTIMIZE_MEMORY */
/*************************************************************************/
/* */
/* 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 )
{
tt_face_get_metrics( face, 0, idx, lsb, aw );
if ( check && face->postscript.isFixedPitch )
*aw = face->horizontal.advance_Width_Max;
}
/*************************************************************************/
/* */
/* Returns the advance width table for a given pixel size if it is found */
/* in the font's `hdmx' table (if any). */
/* */
static FT_Byte*
Get_Advance_WidthPtr( TT_Face face,
FT_Int ppem,
FT_UInt gindex )
{
#ifdef FT_OPTIMIZE_MEMORY
FT_UInt nn;
FT_Byte* result = NULL;
FT_ULong record_size = face->hdmx_record_size;
FT_Byte* record = face->hdmx_table + 8;
for ( nn = 0; nn < face->hdmx_record_count; nn++ )
if ( face->hdmx_record_sizes[nn] == ppem )
{
gindex += 2;
if ( gindex < record_size )
result = record + gindex;
break;
}
return result;
#else
FT_UShort n;
for ( n = 0; n < face->hdmx.num_records; n++ )
if ( face->hdmx.records[n].ppem == ppem )
return &face->hdmx.records[n].widths[gindex];
return NULL;
#endif
}
/*************************************************************************/
/* */
/* 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 )
tt_face_get_metrics( face, 1, idx, tsb, ah );
#if 1 /* Emperically 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
}
#define cur_to_org( n, zone ) \
FT_ARRAY_COPY( (zone)->org, (zone)->cur, (n) )
#define org_to_cur( n, zone ) \
FT_ARRAY_COPY( (zone)->cur, (zone)->org, (n) )
/*************************************************************************/
/* */
/* 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;
}
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->tags = (FT_Byte*)load->outline.tags + start_point;
zone->contours = (FT_UShort*)load->outline.contours + start_contour;
}
#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;
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_Stream stream = loader->stream;
FT_Int byte_len = loader->byte_len - 10;
if ( byte_len < 0 )
return TT_Err_Invalid_Outline;
loader->n_contours = FT_GET_SHORT();
loader->bbox.xMin = FT_GET_SHORT();
loader->bbox.yMin = FT_GET_SHORT();
loader->bbox.xMax = FT_GET_SHORT();
loader->bbox.yMax = FT_GET_SHORT();
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->byte_len = byte_len;
return TT_Err_Ok;
}
FT_CALLBACK_DEF( FT_Error )
TT_Load_Simple_Glyph( TT_Loader load )
{
FT_Error error;
FT_Stream stream = load->stream;
FT_GlyphLoader gloader = load->gloader;
FT_Int n_contours = load->n_contours;
FT_Outline* outline;
TT_Face face = (TT_Face)load->face;
TT_GlyphSlot slot = (TT_GlyphSlot)load->glyph;
FT_UShort n_ins;
FT_Int n, n_points;
FT_Int byte_len = load->byte_len;
FT_Byte *flag, *flag_limit;
FT_Byte c, count;
FT_Vector *vec, *vec_limit;
FT_Pos x;
FT_Short *cont, *cont_limit;
/* reading the contours' endpoints & number of points */
cont = gloader->current.outline.contours;
cont_limit = cont + n_contours;
/* check space for contours array + instructions count */
byte_len -= 2 * ( n_contours + 1 );
if ( byte_len < 0 )
goto Invalid_Outline;
for ( ; cont < cont_limit; cont++ )
cont[0] = FT_GET_USHORT();
n_points = 0;
if ( n_contours > 0 )
n_points = cont[-1] + 1;
error = FT_GlyphLoader_CheckPoints( 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 */
slot->control_len = 0;
slot->control_data = 0;
n_ins = FT_GET_USHORT();
FT_TRACE5(( " Instructions size: %u\n", n_ins ));
if ( n_ins > face->max_profile.maxSizeOfInstructions )
{
FT_TRACE0(( "TT_Load_Simple_Glyph: Too many instructions!\n" ));
error = TT_Err_Too_Many_Hints;
goto Fail;
}
byte_len -= (FT_Int)n_ins;
if ( byte_len < 0 )
{
FT_TRACE0(( "TT_Load_Simple_Glyph: Instruction count mismatch!\n" ));
error = TT_Err_Too_Many_Hints;
goto Fail;
}
#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
if ( ( load->load_flags &
( FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING ) ) == 0 &&
load->instructions )
{
slot->control_len = n_ins;
slot->control_data = load->instructions;
FT_MEM_COPY( load->instructions, stream->cursor, (FT_Long)n_ins );
}
#endif /* TT_CONFIG_OPTION_BYTECODE_INTERPRETER */
stream->cursor += (FT_Int)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 ( --byte_len < 0 )
goto Invalid_Outline;
*flag++ = c = FT_GET_BYTE();
if ( c & 8 )
{
if ( --byte_len < 0 )
goto Invalid_Outline;
count = FT_GET_BYTE();
if ( flag + (FT_Int)count > flag_limit )
goto Invalid_Outline;
for ( ; count > 0; count-- )
*flag++ = c;
}
}
/* check that there is enough room to load the coordinates */
for ( flag = (FT_Byte*)outline->tags; flag < flag_limit; flag++ )
{
if ( *flag & 2 )
byte_len -= 1;
else if ( ( *flag & 16 ) == 0 )
byte_len -= 2;
if ( *flag & 4 )
byte_len -= 1;
else if ( ( *flag & 32 ) == 0 )
byte_len -= 2;
}
if ( byte_len < 0 )
goto Invalid_Outline;
/* reading the X coordinates */
vec = outline->points;
vec_limit = vec + n_points;
flag = (FT_Byte*)outline->tags;
x = 0;
for ( ; vec < vec_limit; vec++, flag++ )
{
FT_Pos y = 0;
if ( *flag & 2 )
{
y = (FT_Pos)FT_GET_BYTE();
if ( ( *flag & 16 ) == 0 )
y = -y;
}
else if ( ( *flag & 16 ) == 0 )
y = (FT_Pos)FT_GET_SHORT();
x += y;
vec->x = x;
}
/* 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;
if ( *flag & 4 )
{
y = (FT_Pos)FT_GET_BYTE();
if ( ( *flag & 32 ) == 0 )
y = -y;
}
else if ( ( *flag & 32 ) == 0 )
y = (FT_Pos)FT_GET_SHORT();
x += y;
vec->y = x;
}
/* clear the touch tags */
for ( n = 0; n < n_points; n++ )
outline->tags[n] &= FT_CURVE_TAG_ON;
outline->n_points = (FT_UShort)n_points;
outline->n_contours = (FT_Short) n_contours;
load->byte_len = byte_len;
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_Stream stream = loader->stream;
FT_GlyphLoader gloader = loader->gloader;
FT_SubGlyph subglyph;
FT_UInt num_subglyphs;
FT_Int byte_len = loader->byte_len;
num_subglyphs = 0;
do
{
FT_Fixed xx, xy, yy, yx;
/* check that we can load a new subglyph */
error = FT_GlyphLoader_CheckSubGlyphs( gloader, num_subglyphs + 1 );
if ( error )
goto Fail;
/* check space */
byte_len -= 4;
if ( byte_len < 0 )
goto Invalid_Composite;
subglyph = gloader->current.subglyphs + num_subglyphs;
subglyph->arg1 = subglyph->arg2 = 0;
subglyph->flags = FT_GET_USHORT();
subglyph->index = FT_GET_USHORT();
/* check space */
byte_len -= 2;
if ( subglyph->flags & ARGS_ARE_WORDS )
byte_len -= 2;
if ( subglyph->flags & WE_HAVE_A_SCALE )
byte_len -= 2;
else if ( subglyph->flags & WE_HAVE_AN_XY_SCALE )
byte_len -= 4;
else if ( subglyph->flags & WE_HAVE_A_2X2 )
byte_len -= 8;
if ( byte_len < 0 )
goto Invalid_Composite;
/* read arguments */
if ( subglyph->flags & ARGS_ARE_WORDS )
{
subglyph->arg1 = FT_GET_SHORT();
subglyph->arg2 = FT_GET_SHORT();
}
else
{
subglyph->arg1 = FT_GET_CHAR();
subglyph->arg2 = FT_GET_CHAR();
}
/* read transform */
xx = yy = 0x10000L;
xy = yx = 0;
if ( subglyph->flags & WE_HAVE_A_SCALE )
{
xx = (FT_Fixed)FT_GET_SHORT() << 2;
yy = xx;
}
else if ( subglyph->flags & WE_HAVE_AN_XY_SCALE )
{
xx = (FT_Fixed)FT_GET_SHORT() << 2;
yy = (FT_Fixed)FT_GET_SHORT() << 2;
}
else if ( subglyph->flags & WE_HAVE_A_2X2 )
{
xx = (FT_Fixed)FT_GET_SHORT() << 2;
yx = (FT_Fixed)FT_GET_SHORT() << 2;
xy = (FT_Fixed)FT_GET_SHORT() << 2;
yy = (FT_Fixed)FT_GET_SHORT() << 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_CONFIG_OPTION_BYTECODE_INTERPRETER
{
/* 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() +
stream->cursor - stream->limit );
}
#endif
loader->byte_len = byte_len;
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;
}
/*************************************************************************/
/* */
/* <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 load,
FT_Bool debug )
{
FT_GlyphLoader gloader = load->gloader;
FT_Outline* outline = &gloader->current.outline;
FT_UInt n_points = outline->n_points;
#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
FT_UInt n_ins;
#endif
TT_GlyphZone zone = &load->zone;
FT_Error error = TT_Err_Ok;
FT_UNUSED( debug ); /* used by truetype interpreter only */
#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
n_ins = load->glyph->control_len;
#endif
/* add shadow points */
/* Add two horizontal shadow points at n and n+1. */
/* We need the left side bearing and advance width. */
/* Add two vertical shadow points at n+2 and n+3. */
/* We need the top side bearing and advance height. */
{
FT_Vector* pp1;
FT_Vector* pp2;
FT_Vector* pp3;
FT_Vector* pp4;
/* pp1 = xMin - lsb */
pp1 = outline->points + n_points;
pp1->x = load->bbox.xMin - load->left_bearing;
pp1->y = 0;
/* pp2 = pp1 + aw */
pp2 = pp1 + 1;
pp2->x = pp1->x + load->advance;
pp2->y = 0;
/* pp3 = top side bearing */
pp3 = pp1 + 2;
pp3->x = 0;
pp3->y = load->top_bearing + load->bbox.yMax;
/* pp4 = pp3 - ah */
pp4 = pp1 + 3;
pp4->x = 0;
pp4->y = pp3->y - load->vadvance;
outline->tags[n_points ] = 0;
outline->tags[n_points + 1] = 0;
outline->tags[n_points + 2] = 0;
outline->tags[n_points + 3] = 0;
}
/* Note that we return four more points that are not */
/* part of the glyph outline. */
n_points += 4;
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
if ( ((TT_Face)load->face)->doblend )
{
/* Deltas apply to the unscaled data. */
FT_Vector* deltas;
FT_Memory memory = load->face->memory;
FT_StreamRec saved_stream = *(load->stream);
FT_UInt i;
/* TT_Vary_Get_Glyph_Deltas uses a frame, thus we have to save */
/* (and restore) the current one */
load->stream->cursor = 0;
load->stream->limit = 0;
error = TT_Vary_Get_Glyph_Deltas( (TT_Face)(load->face),
load->glyph_index,
&deltas,
n_points );
*(load->stream) = saved_stream;
if ( error )
goto Exit;
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 */
/* set up zone for hinting */
tt_prepare_zone( zone, &gloader->current, 0, 0 );
/* eventually scale the glyph */
if ( !( load->load_flags & FT_LOAD_NO_SCALE ) )
{
FT_Vector* vec = zone->cur;
FT_Vector* limit = vec + n_points;
FT_Fixed x_scale = ((TT_Size)load->size)->metrics.x_scale;
FT_Fixed y_scale = ((TT_Size)load->size)->metrics.y_scale;
/* first scale the glyph points */
for ( ; vec < limit; vec++ )
{
vec->x = FT_MulFix( vec->x, x_scale );
vec->y = FT_MulFix( vec->y, y_scale );
}
}
cur_to_org( n_points, zone );
/* eventually hint the glyph */
if ( IS_HINTED( load->load_flags ) )
{
FT_Pos x = zone->org[n_points-4].x;
x = FT_PIX_ROUND( x ) - x;
translate_array( n_points, zone->org, x, 0 );
org_to_cur( n_points, zone );
zone->cur[n_points - 3].x = FT_PIX_ROUND( zone->cur[n_points - 3].x );
zone->cur[n_points - 1].y = FT_PIX_ROUND( zone->cur[n_points - 1].y );
#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
/* now consider hinting */
if ( n_ins > 0 )
{
error = TT_Set_CodeRange( load->exec, tt_coderange_glyph,
load->exec->glyphIns, n_ins );
if ( error )
goto Exit;
load->exec->is_composite = FALSE;
load->exec->pts = *zone;
load->exec->pts.n_points += 4;
error = TT_Run_Context( load->exec, debug );
if ( error && load->exec->pedantic_hinting )
goto Exit;
error = TT_Err_Ok; /* ignore bytecode errors in non-pedantic mode */
}
#endif /* TT_CONFIG_OPTION_BYTECODE_INTERPRETER */
}
/* save glyph phantom points */
if ( !load->preserve_pps )
{
load->pp1 = zone->cur[n_points - 4];
load->pp2 = zone->cur[n_points - 3];
load->pp3 = zone->cur[n_points - 2];
load->pp4 = zone->cur[n_points - 1];
}
#if defined( TT_CONFIG_OPTION_BYTECODE_INTERPRETER ) || \
defined( TT_CONFIG_OPTION_GX_VAR_SUPPORT )
Exit:
#endif
return error;
}
/*************************************************************************/
/* */
/* <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 )
{
#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
FT_Stream stream = loader->stream;
#endif
FT_Error error;
TT_Face face = (TT_Face)loader->face;
FT_ULong offset;
FT_Int contours_count;
FT_UInt num_points, count;
FT_Fixed x_scale, y_scale;
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 TT_CONFIG_OPTION_GX_VAR_SUPPORT
FT_Vector *deltas;
#endif
if ( recurse_count >= TT_MAX_COMPOSITE_RECURSE )
{
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;
num_points = 0;
x_scale = 0x10000L;
y_scale = 0x10000L;
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;
}
/* 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 ??? */
if ( face->root.internal->incremental_interface &&
face->root.internal->incremental_interface->funcs->get_glyph_metrics )
{
FT_Incremental_MetricsRec 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
#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;
}
}
#ifdef FT_CONFIG_OPTION_INCREMENTAL
/* Set `offset' to the start of the glyph program relative to the */
/* start of the 'glyf' table, and `count' to the length of the */
/* glyph program in bytes. */
/* */
/* 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;
count = 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, &count );
if ( count == 0 )
{
/* as described by Frederic Loyer, these are spaces, and */
/* not the unknown glyph. */
loader->bbox.xMin = 0;
loader->bbox.xMax = 0;
loader->bbox.yMin = 0;
loader->bbox.yMax = 0;
loader->pp1.x = 0;
loader->pp2.x = loader->advance;
loader->pp3.y = 0;
loader->pp4.y = loader->pp3.y-loader->vadvance;
#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->pp2.x = FT_MulFix( loader->pp2.x, x_scale );
loader->pp4.y = FT_MulFix( loader->pp4.y, y_scale );
}
#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
if ( loader->exec )
loader->exec->glyphSize = 0;
#endif
error = TT_Err_Ok;
goto Exit;
}
loader->byte_len = (FT_Int)count;
offset = loader->glyf_offset + offset;
/* access glyph frame */
error = face->access_glyph_frame( loader, glyph_index, offset, count );
if ( error )
goto Exit;
opened_frame = 1;
/* read first glyph header */
error = face->read_glyph_header( loader );
if ( error )
goto Fail;
contours_count = loader->n_contours;
count -= 10;
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;
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
/* if it is a simple glyph, load it */
if ( contours_count >= 0 )
{
/* check that we can add the contours to the glyph */
error = FT_GlyphLoader_CheckPoints( gloader, 0, contours_count );
if ( error )
goto Fail;
error = face->read_simple_glyph( loader );
if ( error )
goto Fail;
#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
{
TT_Size size = (TT_Size)loader->size;
error = TT_Process_Simple_Glyph( loader,
(FT_Bool)( size && size->debug ) );
}
#else
error = TT_Process_Simple_Glyph( loader, 0 );
#endif
if ( error )
goto Fail;
FT_GlyphLoader_Add( gloader );
/* Note: We could have put the simple loader source there */
/* but the code is fat enough already :-) */
}
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
/* otherwise, load a composite! */
else if ( contours_count == -1 )
{
TT_GlyphSlot glyph = (TT_GlyphSlot)loader->glyph;
FT_UInt start_point;
#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
FT_UInt start_contour;
FT_ULong ins_pos; /* position of composite instructions, if any */
#endif
/* for each subglyph, read composite header */
start_point = gloader->base.outline.n_points;
#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
start_contour = gloader->base.outline.n_contours;
#endif
error = face->read_composite_glyph( loader );
if ( error )
goto Fail;
#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
ins_pos = loader->ins_pos;
#endif
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;
/* Note: No subglyph reallocation here, our pointers are stable. */
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 )
{
/* set up remaining glyph fields */
FT_GlyphLoader_Add( gloader );
glyph->num_subglyphs = gloader->base.num_subglyphs;
glyph->format = FT_GLYPH_FORMAT_COMPOSITE;
glyph->subglyphs = gloader->base.subglyphs;
goto Exit;
}
/*********************************************************************/
/*********************************************************************/
/*********************************************************************/
/* Now, read each subglyph independently. */
{
FT_Int n, num_base_points, num_new_points;
FT_SubGlyph subglyph = 0;
FT_UInt num_subglyphs = gloader->current.num_subglyphs;
FT_UInt num_base_subgs = gloader->base.num_subglyphs;
FT_GlyphLoader_Add( gloader );
for ( n = 0; n < (FT_Int)num_subglyphs; n++ )
{
FT_Vector pp1, pp2, pp3, pp4;
FT_Pos x, y;
/* 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;
pp1 = loader->pp1;
pp2 = loader->pp2;
pp3 = loader->pp3;
pp4 = loader->pp4;
num_base_points = gloader->base.outline.n_points;
error = load_truetype_glyph( loader, subglyph->index,
recurse_count + 1 );
if ( error )
goto Fail;
/* restore subglyph pointer */
subglyph = gloader->base.subglyphs + num_base_subgs + n;
if ( subglyph->flags & USE_MY_METRICS )
{
pp1 = loader->pp1;
pp2 = loader->pp2;
pp3 = loader->pp3;
pp4 = loader->pp4;
}
else
{
loader->pp1 = pp1;
loader->pp2 = pp2;
loader->pp3 = pp3;
loader->pp4 = pp4;
}
num_points = gloader->base.outline.n_points;
num_new_points = num_points - num_base_points;
/* now perform the transform required for this subglyph */
if ( subglyph->flags & ( WE_HAVE_A_SCALE |
WE_HAVE_AN_XY_SCALE |
WE_HAVE_A_2X2 ) )
{
FT_Vector* cur = gloader->base.outline.points +
num_base_points;
FT_Vector* org = gloader->base.extra_points +
num_base_points;
FT_Vector* limit = cur + num_new_points;
for ( ; cur < limit; cur++, org++ )
{
FT_Vector_Transform( cur, &subglyph->transform );
FT_Vector_Transform( org, &subglyph->transform );
}
}
/* apply offset */
if ( !( subglyph->flags & ARGS_ARE_XY_VALUES ) )
{
FT_UInt k = subglyph->arg1;
FT_UInt l = subglyph->arg2;
FT_Vector* p1;
FT_Vector* p2;
if ( start_point + k >= (FT_UInt)num_base_points ||
l >= (FT_UInt)num_new_points )
{
error = TT_Err_Invalid_Composite;
goto Fail;
}
l += num_base_points;
p1 = gloader->base.outline.points + start_point + k;
p2 = gloader->base.outline.points + start_point + l;
x = p1->x - p2->x;
y = p1->y - p2->y;
}
else
{
x = subglyph->arg1;
y = subglyph->arg2;
/* 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. */
#ifdef TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED
if ( !( subglyph->flags & UNSCALED_COMPONENT_OFFSET ) &&
#else
if ( ( subglyph->flags & SCALED_COMPONENT_OFFSET ) &&
#endif
( subglyph->flags & ( WE_HAVE_A_SCALE |
WE_HAVE_AN_XY_SCALE |
WE_HAVE_A_2X2 )) )
{
#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 ) )
{
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_new_points,
gloader->base.outline.points + num_base_points,
x, y );
translate_array( num_new_points,
gloader->base.extra_points + num_base_points,
x, y );
}
}
/*******************************************************************/
/*******************************************************************/
/*******************************************************************/
/* we have finished loading all sub-glyphs; now, look for */
/* instructions for this composite! */
#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
if ( num_subglyphs > 0 &&
loader->exec &&
ins_pos > 0 &&
subglyph->flags & WE_HAVE_INSTR )
{
FT_UShort n_ins;
TT_ExecContext exec = loader->exec;
TT_GlyphZone pts;
FT_Vector* pp1;
/* read size of instructions */
if ( FT_STREAM_SEEK( ins_pos ) ||
FT_READ_USHORT( n_ins ) )
goto Fail;
FT_TRACE5(( " Instructions size = %d\n", n_ins ));
/* in some fonts? */
if ( n_ins == 0xFFFFU )
n_ins = 0;
/* check it */
if ( n_ins > face->max_profile.maxSizeOfInstructions )
{
FT_TRACE0(( "Too many instructions (%d) in composite glyph %ld\n",
n_ins, subglyph->index ));
error = TT_Err_Too_Many_Hints;
goto Fail;
}
/* read the instructions */
if ( FT_STREAM_READ( exec->glyphIns, n_ins ) )
goto Fail;
glyph->control_data = exec->glyphIns;
glyph->control_len = n_ins;
error = TT_Set_CodeRange( exec,
tt_coderange_glyph,
exec->glyphIns,
n_ins );
if ( error )
goto Fail;
error = FT_GlyphLoader_CheckPoints( gloader, num_points + 4, 0 );
if ( error )
goto Fail;
/* prepare the execution context */
tt_prepare_zone( &exec->pts, &gloader->base,
start_point, start_contour );
pts = &exec->pts;
pts->n_points = (short)( num_points + 4 );
pts->n_contours = gloader->base.outline.n_contours;
/* add phantom points */
pp1 = pts->cur + num_points;
pp1[0] = loader->pp1;
pp1[1] = loader->pp2;
pp1[2] = loader->pp3;
pp1[3] = loader->pp4;
pts->tags[num_points ] = 0;
pts->tags[num_points + 1] = 0;
pts->tags[num_points + 2] = 0;
pts->tags[num_points + 3] = 0;
/* if hinting, round the phantom points */
if ( IS_HINTED( loader->load_flags ) )
{
pp1[0].x = FT_PIX_ROUND( loader->pp1.x );
pp1[1].x = FT_PIX_ROUND( loader->pp2.x );
pp1[2].y = FT_PIX_ROUND( loader->pp3.y );
pp1[3].y = FT_PIX_ROUND( loader->pp4.y );
}
{
FT_UInt k;
for ( k = 0; k < num_points; k++ )
pts->tags[k] &= FT_CURVE_TAG_ON;
}
cur_to_org( num_points + 4, pts );
/* now consider hinting */
if ( IS_HINTED( loader->load_flags ) && n_ins > 0 )
{
exec->is_composite = TRUE;
error = TT_Run_Context( exec, ((TT_Size)loader->size)->debug );
if ( error && exec->pedantic_hinting )
goto Fail;
}
/* save glyph origin and advance points */
loader->pp1 = pp1[0];
loader->pp2 = pp1[1];
loader->pp3 = pp1[2];
loader->pp4 = pp1[3];
}
#endif /* TT_CONFIG_OPTION_BYTECODE_INTERPRETER */
}
/* end of composite loading */
}
else
{
/* invalid composite count ( negative but not -1 ) */
error = TT_Err_Invalid_Outline;
goto Fail;
}
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
Fail:
if ( opened_frame )
face->forget_glyph_frame( loader );
Exit:
#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 )
{
glyph->outline.flags &= ~FT_OUTLINE_SINGLE_PASS;
/* copy outline to our glyph slot */
FT_GlyphLoader_CopyPoints( glyph->internal->loader, loader->gloader );
glyph->outline = glyph->internal->loader->base.outline;
/* translate array so that (0,0) is the glyph's origin */
FT_Outline_Translate( &glyph->outline, -loader->pp1.x, 0 );
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_Short top_bearing; /* vertical top side bearing (EM units) */
FT_UShort advance_height; /* vertical advance height (EM units) */
FT_Pos left; /* scaled vertical left side bearing */
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_bearing = (FT_Short)FT_DivFix( loader->pp3.y - bbox.yMax,
y_scale );
if ( loader->pp3.y <= loader->pp4.y )
advance_height = 0;
else
advance_height = (FT_UShort)FT_DivFix( loader->pp3.y - loader->pp4.y,
y_scale );
}
else
{
FT_Short max_height, 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 )
{
/* sTypoDescender is negative */
max_height = (FT_Short)(face->os2.sTypoAscender -
face->os2.sTypoDescender);
top_bearing = (FT_Short)( ( max_height - height ) / 2 );
advance_height = (FT_UShort)( max_height + face->os2.sTypoLineGap );
}
else
{
max_height = (FT_Short)(face->horizontal.Ascender +
face->horizontal.Descender);
top_bearing = (FT_Short)( ( max_height - height ) / 2 );
advance_height = (FT_UShort)( max_height +
face->horizontal.Line_Gap );
}
}
#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;
FT_Error error = TT_Err_Ok;
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 )
return error;
top_bearing = (FT_Short)metrics.bearing_y;
advance_height = (FT_UShort)metrics.advance;
}
/* GWW: Do vertical metrics get loaded incrementally too? */
#endif /* FT_CONFIG_OPTION_INCREMENTAL */
/* scale the metrics */
if ( !( loader->load_flags & FT_LOAD_NO_SCALE ) )
{
top = FT_MulFix( top_bearing, y_scale );
advance = FT_MulFix( advance_height, y_scale );
}
else
{
top = top_bearing;
advance = advance_height;
}
/* set the advance height in design units. It is scaled later by */
/* the base layer. */
glyph->linearVertAdvance = advance_height;
/* XXX: for now, we have no better algorithm for the lsb, but it */
/* should work fine. */
/* */
left = ( bbox.xMin - bbox.xMax ) / 2;
glyph->metrics.vertBearingX = left;
glyph->metrics.vertBearingY = top;
glyph->metrics.vertAdvance = advance;
}
/* adjust advance width to the value contained in the hdmx table */
if ( !face->postscript.isFixedPitch && size &&
IS_HINTED( loader->load_flags ) )
{
FT_Byte* widthp = Get_Advance_WidthPtr( 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;
if ( IS_HINTED( loader->load_flags ) )
ft_glyphslot_grid_fit_metrics( glyph );
return 0;
}
/*************************************************************************/
/* */
/* <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 )
{
SFNT_Service sfnt;
TT_Face face;
FT_Stream stream;
FT_Error error;
TT_LoaderRec loader;
face = (TT_Face)glyph->face;
sfnt = (SFNT_Service)face->sfnt;
stream = face->root.stream;
error = TT_Err_Ok;
if ( !size || ( load_flags & FT_LOAD_NO_SCALE ) ||
( load_flags & FT_LOAD_NO_RECURSE ) )
{
size = NULL;
load_flags |= FT_LOAD_NO_SCALE |
FT_LOAD_NO_HINTING |
FT_LOAD_NO_BITMAP;
}
glyph->num_subglyphs = 0;
#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 &&
size->strike_index != 0xFFFFU &&
sfnt->load_sbits &&
( load_flags & FT_LOAD_NO_BITMAP ) == 0 )
{
TT_SBit_MetricsRec metrics;
error = sfnt->load_sbit_image( face,
(FT_ULong)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 */
/* return immediately if we only want the embedded bitmaps */
if ( load_flags & FT_LOAD_SBITS_ONLY )
return TT_Err_Invalid_Argument;
/* 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
/* Don't look for the glyph table if this is an incremental font. */
if ( !face->root.internal->incremental_interface )
#endif
{
error = face->goto_table( face, TTAG_glyf, stream, 0 );
if ( error )
{
FT_ERROR(( "TT_Load_Glyph: could not access glyph table\n" ));
goto Exit;
}
}
FT_MEM_ZERO( &loader, sizeof ( loader ) );
/* update the glyph zone bounds */
{
FT_GlyphLoader gloader = FT_FACE_DRIVER( face )->glyph_loader;
loader.gloader = gloader;
FT_GlyphLoader_Rewind( gloader );
tt_prepare_zone( &loader.zone, &gloader->base, 0, 0 );
tt_prepare_zone( &loader.base, &gloader->base, 0, 0 );
}
#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
if ( size )
{
/* query new execution context */
loader.exec = size->debug ? size->context : TT_New_Context( face );
if ( !loader.exec )
return TT_Err_Could_Not_Find_Context;
TT_Load_Context( loader.exec, face, size );
loader.instructions = loader.exec->glyphIns;
/* load default graphics state - if needed */
if ( size->GS.instruct_control & 2 )
loader.exec->GS = tt_default_graphics_state;
loader.exec->pedantic_hinting =
FT_BOOL( load_flags & FT_LOAD_PEDANTIC );
loader.exec->grayscale =
FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) != FT_LOAD_TARGET_MONO );
}
#endif /* TT_CONFIG_OPTION_BYTECODE_INTERPRETER */
/* clear all outline flags, except the `owner' one */
glyph->outline.flags = 0;
/* let's initialize the rest of our loader now */
loader.load_flags = load_flags;
loader.face = (FT_Face)face;
loader.size = (FT_Size)size;
loader.glyph = (FT_GlyphSlot)glyph;
loader.stream = stream;
#ifdef FT_CONFIG_OPTION_INCREMENTAL
if ( face->root.internal->incremental_interface )
loader.glyf_offset = 0;
else
#endif
loader.glyf_offset = FT_STREAM_POS();
#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
/* if the cvt program has disabled hinting, the argument */
/* is ignored. */
if ( size && ( size->GS.instruct_control & 1 ) )
loader.load_flags |= FT_LOAD_NO_HINTING;
#endif /* TT_CONFIG_OPTION_BYTECODE_INTERPRETER */
/* Main loading loop */
glyph->format = FT_GLYPH_FORMAT_OUTLINE;
glyph->num_subglyphs = 0;
error = load_truetype_glyph( &loader, glyph_index, 0 );
if ( !error )
compute_glyph_metrics( &loader, glyph_index );
#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
if ( !size || !size->debug )
TT_Done_Context( loader.exec );
#endif /* TT_CONFIG_OPTION_BYTECODE_INTERPRETER */
/* 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 ( size && size->root.metrics.y_ppem < 24 )
glyph->outline.flags |= FT_OUTLINE_HIGH_PRECISION;
Exit:
return error;
}
/* END */
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