?? ttgload.c
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/***************************************************************************/
/* */
/* ttgload.c */
/* */
/* TrueType Glyph Loader (body). */
/* */
/* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006 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 /* 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
}
/*************************************************************************/
/* */
/* 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;
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;
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;
/* 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 */
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;
/* 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;
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 ( IS_HINTED( load->load_flags ) )
{
load->glyph->control_len = n_ins;
load->glyph->control_data = load->exec->glyphIns;
FT_MEM_COPY( load->exec->glyphIns, 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;
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