ref: 119e404b892dc8bf7db53e868039aec187042587
dir: /src/sfnt/sfwoff2.c/
/****************************************************************************
*
* sfwoff2.c
*
* WOFF2 format management (base).
*
* Copyright (C) 2019-2022 by
* Nikhil Ramakrishnan, 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 "sfwoff2.h"
#include "woff2tags.h"
#include <freetype/tttags.h>
#include <freetype/internal/ftdebug.h>
#include <freetype/internal/ftstream.h>
#ifdef FT_CONFIG_OPTION_USE_BROTLI
#include <brotli/decode.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 sfwoff2
#define READ_255USHORT( var ) FT_SET_ERROR( Read255UShort( stream, &var ) )
#define READ_BASE128( var ) FT_SET_ERROR( ReadBase128( stream, &var ) )
/* `var' should be FT_ULong */
#define ROUND4( var ) ( ( var + 3 ) & ~3UL )
#define WRITE_USHORT( p, v ) \
do \
{ \
*(p)++ = (FT_Byte)( (v) >> 8 ); \
*(p)++ = (FT_Byte)( (v) >> 0 ); \
\
} while ( 0 )
#define WRITE_ULONG( p, v ) \
do \
{ \
*(p)++ = (FT_Byte)( (v) >> 24 ); \
*(p)++ = (FT_Byte)( (v) >> 16 ); \
*(p)++ = (FT_Byte)( (v) >> 8 ); \
*(p)++ = (FT_Byte)( (v) >> 0 ); \
\
} while ( 0 )
#define WRITE_SHORT( p, v ) \
do \
{ \
*(p)++ = (FT_Byte)( (v) >> 8 ); \
*(p)++ = (FT_Byte)( (v) >> 0 ); \
\
} while ( 0 )
#define WRITE_SFNT_BUF( buf, s ) \
write_buf( &sfnt, sfnt_size, &dest_offset, buf, s, memory )
#define WRITE_SFNT_BUF_AT( offset, buf, s ) \
write_buf( &sfnt, sfnt_size, &offset, buf, s, memory )
#define N_CONTOUR_STREAM 0
#define N_POINTS_STREAM 1
#define FLAG_STREAM 2
#define GLYPH_STREAM 3
#define COMPOSITE_STREAM 4
#define BBOX_STREAM 5
#define INSTRUCTION_STREAM 6
#define HAVE_OVERLAP_SIMPLE_BITMAP 0x1
static void
stream_close( FT_Stream stream )
{
FT_Memory memory = stream->memory;
FT_FREE( stream->base );
stream->size = 0;
stream->close = NULL;
}
FT_COMPARE_DEF( int )
compare_tags( const void* a,
const void* b )
{
WOFF2_Table table1 = *(WOFF2_Table*)a;
WOFF2_Table table2 = *(WOFF2_Table*)b;
FT_Tag tag1 = table1->Tag;
FT_Tag tag2 = table2->Tag;
if ( tag1 > tag2 )
return 1;
else if ( tag1 < tag2 )
return -1;
else
return 0;
}
static FT_Error
Read255UShort( FT_Stream stream,
FT_UShort* value )
{
const FT_Byte oneMoreByteCode1 = 255;
const FT_Byte oneMoreByteCode2 = 254;
const FT_Byte wordCode = 253;
const FT_UShort lowestUCode = 253;
FT_Error error = FT_Err_Ok;
FT_Byte code;
FT_Byte result_byte = 0;
FT_UShort result_short = 0;
if ( FT_READ_BYTE( code ) )
return error;
if ( code == wordCode )
{
/* Read next two bytes and store `FT_UShort' value. */
if ( FT_READ_USHORT( result_short ) )
return error;
*value = result_short;
return FT_Err_Ok;
}
else if ( code == oneMoreByteCode1 )
{
if ( FT_READ_BYTE( result_byte ) )
return error;
*value = result_byte + lowestUCode;
return FT_Err_Ok;
}
else if ( code == oneMoreByteCode2 )
{
if ( FT_READ_BYTE( result_byte ) )
return error;
*value = result_byte + lowestUCode * 2;
return FT_Err_Ok;
}
else
{
*value = code;
return FT_Err_Ok;
}
}
static FT_Error
ReadBase128( FT_Stream stream,
FT_ULong* value )
{
FT_ULong result = 0;
FT_Int i;
FT_Byte code;
FT_Error error = FT_Err_Ok;
for ( i = 0; i < 5; ++i )
{
code = 0;
if ( FT_READ_BYTE( code ) )
return error;
/* Leading zeros are invalid. */
if ( i == 0 && code == 0x80 )
return FT_THROW( Invalid_Table );
/* If any of top seven bits are set then we're about to overflow. */
if ( result & 0xfe000000 )
return FT_THROW( Invalid_Table );
result = ( result << 7 ) | ( code & 0x7f );
/* Spin until most significant bit of data byte is false. */
if ( ( code & 0x80 ) == 0 )
{
*value = result;
return FT_Err_Ok;
}
}
/* Make sure not to exceed the size bound. */
return FT_THROW( Invalid_Table );
}
/* Extend memory of `dst_bytes' buffer and copy data from `src'. */
static FT_Error
write_buf( FT_Byte** dst_bytes,
FT_ULong* dst_size,
FT_ULong* offset,
FT_Byte* src,
FT_ULong size,
FT_Memory memory )
{
FT_Error error = FT_Err_Ok;
/* We are reallocating memory for `dst', so its pointer may change. */
FT_Byte* dst = *dst_bytes;
/* Check whether we are within limits. */
if ( ( *offset + size ) > WOFF2_DEFAULT_MAX_SIZE )
return FT_THROW( Array_Too_Large );
/* Reallocate `dst'. */
if ( ( *offset + size ) > *dst_size )
{
FT_TRACE6(( "Reallocating %lu to %lu.\n",
*dst_size, (*offset + size) ));
if ( FT_REALLOC( dst,
(FT_ULong)( *dst_size ),
(FT_ULong)( *offset + size ) ) )
goto Exit;
*dst_size = *offset + size;
}
/* Copy data. */
ft_memcpy( dst + *offset, src, size );
*offset += size;
/* Set pointer of `dst' to its correct value. */
*dst_bytes = dst;
Exit:
return error;
}
/* Pad buffer to closest multiple of 4. */
static FT_Error
pad4( FT_Byte** sfnt_bytes,
FT_ULong* sfnt_size,
FT_ULong* out_offset,
FT_Memory memory )
{
FT_Byte* sfnt = *sfnt_bytes;
FT_ULong dest_offset = *out_offset;
FT_Byte zeroes[] = { 0, 0, 0 };
FT_ULong pad_bytes;
if ( dest_offset + 3 < dest_offset )
return FT_THROW( Invalid_Table );
pad_bytes = ROUND4( dest_offset ) - dest_offset;
if ( pad_bytes > 0 )
{
if ( WRITE_SFNT_BUF( &zeroes[0], pad_bytes ) )
return FT_THROW( Invalid_Table );
}
*sfnt_bytes = sfnt;
*out_offset = dest_offset;
return FT_Err_Ok;
}
/* Calculate table checksum of `buf'. */
static FT_ULong
compute_ULong_sum( FT_Byte* buf,
FT_ULong size )
{
FT_ULong checksum = 0;
FT_ULong aligned_size = size & ~3UL;
FT_ULong i;
FT_ULong v;
for ( i = 0; i < aligned_size; i += 4 )
checksum += ( (FT_ULong)buf[i ] << 24 ) |
( (FT_ULong)buf[i + 1] << 16 ) |
( (FT_ULong)buf[i + 2] << 8 ) |
( (FT_ULong)buf[i + 3] << 0 );
/* If size is not aligned to 4, treat as if it is padded with 0s. */
if ( size != aligned_size )
{
v = 0;
for ( i = aligned_size ; i < size; ++i )
v |= (FT_ULong)buf[i] << ( 24 - 8 * ( i & 3 ) );
checksum += v;
}
return checksum;
}
static FT_Error
woff2_decompress( FT_Byte* dst,
FT_ULong dst_size,
const FT_Byte* src,
FT_ULong src_size )
{
/* this cast is only of importance on 32bit systems; */
/* we don't validate it */
FT_Offset uncompressed_size = (FT_Offset)dst_size;
BrotliDecoderResult result;
result = BrotliDecoderDecompress( src_size,
src,
&uncompressed_size,
dst );
if ( result != BROTLI_DECODER_RESULT_SUCCESS ||
uncompressed_size != dst_size )
{
FT_ERROR(( "woff2_decompress: Stream length mismatch.\n" ));
return FT_THROW( Invalid_Table );
}
FT_TRACE2(( "woff2_decompress: Brotli stream decompressed.\n" ));
return FT_Err_Ok;
}
static WOFF2_Table
find_table( WOFF2_Table* tables,
FT_UShort num_tables,
FT_Tag tag )
{
FT_Int i;
for ( i = 0; i < num_tables; i++ )
{
if ( tables[i]->Tag == tag )
return tables[i];
}
return NULL;
}
/* Read `numberOfHMetrics' field from `hhea' table. */
static FT_Error
read_num_hmetrics( FT_Stream stream,
FT_UShort* num_hmetrics )
{
FT_Error error = FT_Err_Ok;
FT_UShort num_metrics;
if ( FT_STREAM_SKIP( 34 ) )
return FT_THROW( Invalid_Table );
if ( FT_READ_USHORT( num_metrics ) )
return FT_THROW( Invalid_Table );
*num_hmetrics = num_metrics;
return error;
}
/* An auxiliary function for overflow-safe addition. */
static FT_Int
with_sign( FT_Byte flag,
FT_Int base_val )
{
/* Precondition: 0 <= base_val < 65536 (to avoid overflow). */
return ( flag & 1 ) ? base_val : -base_val;
}
/* An auxiliary function for overflow-safe addition. */
static FT_Int
safe_int_addition( FT_Int a,
FT_Int b,
FT_Int* result )
{
if ( ( ( a > 0 ) && ( b > FT_INT_MAX - a ) ) ||
( ( a < 0 ) && ( b < FT_INT_MIN - a ) ) )
return FT_THROW( Invalid_Table );
*result = a + b;
return FT_Err_Ok;
}
/*
* Decode variable-length (flag, xCoordinate, yCoordinate) triplet for a
* simple glyph. See
*
* https://www.w3.org/TR/WOFF2/#triplet_decoding
*/
static FT_Error
triplet_decode( const FT_Byte* flags_in,
const FT_Byte* in,
FT_ULong in_size,
FT_ULong n_points,
WOFF2_Point result,
FT_ULong* in_bytes_used )
{
FT_Int x = 0;
FT_Int y = 0;
FT_Int dx;
FT_Int dy;
FT_Int b0, b1, b2;
FT_ULong triplet_index = 0;
FT_ULong data_bytes;
FT_UInt i;
if ( n_points > in_size )
return FT_THROW( Invalid_Table );
for ( i = 0; i < n_points; ++i )
{
FT_Byte flag = flags_in[i];
FT_Bool on_curve = !( flag >> 7 );
flag &= 0x7f;
if ( flag < 84 )
data_bytes = 1;
else if ( flag < 120 )
data_bytes = 2;
else if ( flag < 124 )
data_bytes = 3;
else
data_bytes = 4;
/* Overflow checks */
if ( triplet_index + data_bytes > in_size ||
triplet_index + data_bytes < triplet_index )
return FT_THROW( Invalid_Table );
if ( flag < 10 )
{
dx = 0;
dy = with_sign( flag,
( ( flag & 14 ) << 7 ) + in[triplet_index] );
}
else if ( flag < 20 )
{
dx = with_sign( flag,
( ( ( flag - 10 ) & 14 ) << 7 ) +
in[triplet_index] );
dy = 0;
}
else if ( flag < 84 )
{
b0 = flag - 20;
b1 = in[triplet_index];
dx = with_sign( flag,
1 + ( b0 & 0x30 ) + ( b1 >> 4 ) );
dy = with_sign( flag >> 1,
1 + ( ( b0 & 0x0c ) << 2 ) + ( b1 & 0x0f ) );
}
else if ( flag < 120 )
{
b0 = flag - 84;
dx = with_sign( flag,
1 + ( ( b0 / 12 ) << 8 ) + in[triplet_index] );
dy = with_sign( flag >> 1,
1 + ( ( ( b0 % 12 ) >> 2 ) << 8 ) +
in[triplet_index + 1] );
}
else if ( flag < 124 )
{
b2 = in[triplet_index + 1];
dx = with_sign( flag,
( in[triplet_index] << 4 ) + ( b2 >> 4 ) );
dy = with_sign( flag >> 1,
( ( b2 & 0x0f ) << 8 ) + in[triplet_index + 2] );
}
else
{
dx = with_sign( flag,
( in[triplet_index] << 8 ) +
in[triplet_index + 1] );
dy = with_sign( flag >> 1,
( in[triplet_index + 2] << 8 ) +
in[triplet_index + 3] );
}
triplet_index += data_bytes;
if ( safe_int_addition( x, dx, &x ) )
return FT_THROW( Invalid_Table );
if ( safe_int_addition( y, dy, &y ) )
return FT_THROW( Invalid_Table );
result[i].x = x;
result[i].y = y;
result[i].on_curve = on_curve;
}
*in_bytes_used = triplet_index;
return FT_Err_Ok;
}
/* Store decoded points in glyph buffer. */
static FT_Error
store_points( FT_ULong n_points,
const WOFF2_Point points,
FT_UShort n_contours,
FT_UShort instruction_len,
FT_Bool have_overlap,
FT_Byte* dst,
FT_ULong dst_size,
FT_ULong* glyph_size )
{
FT_UInt flag_offset = 10 + ( 2 * n_contours ) + 2 + instruction_len;
FT_Byte last_flag = 0xFFU;
FT_Byte repeat_count = 0;
FT_Int last_x = 0;
FT_Int last_y = 0;
FT_UInt x_bytes = 0;
FT_UInt y_bytes = 0;
FT_UInt xy_bytes;
FT_UInt i;
FT_UInt x_offset;
FT_UInt y_offset;
FT_Byte* pointer;
for ( i = 0; i < n_points; ++i )
{
const WOFF2_PointRec point = points[i];
FT_Byte flag = point.on_curve ? GLYF_ON_CURVE : 0;
FT_Int dx = point.x - last_x;
FT_Int dy = point.y - last_y;
if ( i == 0 && have_overlap )
flag |= GLYF_OVERLAP_SIMPLE;
if ( dx == 0 )
flag |= GLYF_THIS_X_IS_SAME;
else if ( dx > -256 && dx < 256 )
{
flag |= GLYF_X_SHORT | ( dx > 0 ? GLYF_THIS_X_IS_SAME : 0 );
x_bytes += 1;
}
else
x_bytes += 2;
if ( dy == 0 )
flag |= GLYF_THIS_Y_IS_SAME;
else if ( dy > -256 && dy < 256 )
{
flag |= GLYF_Y_SHORT | ( dy > 0 ? GLYF_THIS_Y_IS_SAME : 0 );
y_bytes += 1;
}
else
y_bytes += 2;
if ( flag == last_flag && repeat_count != 255 )
{
dst[flag_offset - 1] |= GLYF_REPEAT;
repeat_count++;
}
else
{
if ( repeat_count != 0 )
{
if ( flag_offset >= dst_size )
return FT_THROW( Invalid_Table );
dst[flag_offset++] = repeat_count;
}
if ( flag_offset >= dst_size )
return FT_THROW( Invalid_Table );
dst[flag_offset++] = flag;
repeat_count = 0;
}
last_x = point.x;
last_y = point.y;
last_flag = flag;
}
if ( repeat_count != 0 )
{
if ( flag_offset >= dst_size )
return FT_THROW( Invalid_Table );
dst[flag_offset++] = repeat_count;
}
xy_bytes = x_bytes + y_bytes;
if ( xy_bytes < x_bytes ||
flag_offset + xy_bytes < flag_offset ||
flag_offset + xy_bytes > dst_size )
return FT_THROW( Invalid_Table );
x_offset = flag_offset;
y_offset = flag_offset + x_bytes;
last_x = 0;
last_y = 0;
for ( i = 0; i < n_points; ++i )
{
FT_Int dx = points[i].x - last_x;
FT_Int dy = points[i].y - last_y;
if ( dx == 0 )
;
else if ( dx > -256 && dx < 256 )
dst[x_offset++] = (FT_Byte)FT_ABS( dx );
else
{
pointer = dst + x_offset;
WRITE_SHORT( pointer, dx );
x_offset += 2;
}
last_x += dx;
if ( dy == 0 )
;
else if ( dy > -256 && dy < 256 )
dst[y_offset++] = (FT_Byte)FT_ABS( dy );
else
{
pointer = dst + y_offset;
WRITE_SHORT( pointer, dy );
y_offset += 2;
}
last_y += dy;
}
*glyph_size = y_offset;
return FT_Err_Ok;
}
static void
compute_bbox( FT_ULong n_points,
const WOFF2_Point points,
FT_Byte* dst,
FT_UShort* src_x_min )
{
FT_Int x_min = 0;
FT_Int y_min = 0;
FT_Int x_max = 0;
FT_Int y_max = 0;
FT_UInt i;
FT_ULong offset;
FT_Byte* pointer;
if ( n_points > 0 )
{
x_min = points[0].x;
y_min = points[0].y;
x_max = points[0].x;
y_max = points[0].y;
}
for ( i = 1; i < n_points; ++i )
{
FT_Int x = points[i].x;
FT_Int y = points[i].y;
x_min = FT_MIN( x, x_min );
y_min = FT_MIN( y, y_min );
x_max = FT_MAX( x, x_max );
y_max = FT_MAX( y, y_max );
}
/* Write values to `glyf' record. */
offset = 2;
pointer = dst + offset;
WRITE_SHORT( pointer, x_min );
WRITE_SHORT( pointer, y_min );
WRITE_SHORT( pointer, x_max );
WRITE_SHORT( pointer, y_max );
*src_x_min = (FT_UShort)x_min;
}
static FT_Error
compositeGlyph_size( FT_Stream stream,
FT_ULong offset,
FT_ULong* size,
FT_Bool* have_instructions )
{
FT_Error error = FT_Err_Ok;
FT_ULong start_offset = offset;
FT_Bool we_have_inst = FALSE;
FT_UShort flags = FLAG_MORE_COMPONENTS;
if ( FT_STREAM_SEEK( start_offset ) )
goto Exit;
while ( flags & FLAG_MORE_COMPONENTS )
{
FT_ULong arg_size;
if ( FT_READ_USHORT( flags ) )
goto Exit;
we_have_inst |= ( flags & FLAG_WE_HAVE_INSTRUCTIONS ) != 0;
/* glyph index */
arg_size = 2;
if ( flags & FLAG_ARG_1_AND_2_ARE_WORDS )
arg_size += 4;
else
arg_size += 2;
if ( flags & FLAG_WE_HAVE_A_SCALE )
arg_size += 2;
else if ( flags & FLAG_WE_HAVE_AN_X_AND_Y_SCALE )
arg_size += 4;
else if ( flags & FLAG_WE_HAVE_A_TWO_BY_TWO )
arg_size += 8;
if ( FT_STREAM_SKIP( arg_size ) )
goto Exit;
}
*size = FT_STREAM_POS() - start_offset;
*have_instructions = we_have_inst;
Exit:
return error;
}
/* Store loca values (provided by `reconstruct_glyf') to output stream. */
static FT_Error
store_loca( FT_ULong* loca_values,
FT_ULong loca_values_size,
FT_UShort index_format,
FT_ULong* checksum,
FT_Byte** sfnt_bytes,
FT_ULong* sfnt_size,
FT_ULong* out_offset,
FT_Memory memory )
{
FT_Error error = FT_Err_Ok;
FT_Byte* sfnt = *sfnt_bytes;
FT_ULong dest_offset = *out_offset;
FT_Byte* loca_buf = NULL;
FT_Byte* dst = NULL;
FT_UInt i = 0;
FT_ULong loca_buf_size;
const FT_ULong offset_size = index_format ? 4 : 2;
if ( ( loca_values_size << 2 ) >> 2 != loca_values_size )
goto Fail;
loca_buf_size = loca_values_size * offset_size;
if ( FT_QNEW_ARRAY( loca_buf, loca_buf_size ) )
goto Fail;
dst = loca_buf;
for ( i = 0; i < loca_values_size; i++ )
{
FT_ULong value = loca_values[i];
if ( index_format )
WRITE_ULONG( dst, value );
else
WRITE_USHORT( dst, ( value >> 1 ) );
}
*checksum = compute_ULong_sum( loca_buf, loca_buf_size );
/* Write `loca' table to sfnt buffer. */
if ( WRITE_SFNT_BUF( loca_buf, loca_buf_size ) )
goto Fail;
/* Set pointer `sfnt_bytes' to its correct value. */
*sfnt_bytes = sfnt;
*out_offset = dest_offset;
FT_FREE( loca_buf );
return error;
Fail:
if ( !error )
error = FT_THROW( Invalid_Table );
FT_FREE( loca_buf );
return error;
}
static FT_Error
reconstruct_glyf( FT_Stream stream,
FT_ULong* glyf_checksum,
FT_ULong* loca_checksum,
FT_Byte** sfnt_bytes,
FT_ULong* sfnt_size,
FT_ULong* out_offset,
WOFF2_Info info,
FT_Memory memory )
{
FT_Error error = FT_Err_Ok;
FT_Byte* sfnt = *sfnt_bytes;
/* current position in stream */
const FT_ULong pos = FT_STREAM_POS();
FT_UInt num_substreams = 7;
FT_UShort option_flags;
FT_UShort num_glyphs;
FT_UShort index_format;
FT_ULong expected_loca_length;
FT_UInt offset;
FT_UInt i;
FT_ULong points_size;
FT_ULong glyph_buf_size;
FT_ULong bbox_bitmap_offset;
FT_ULong bbox_bitmap_length;
FT_ULong overlap_bitmap_offset = 0;
FT_ULong overlap_bitmap_length = 0;
const FT_ULong glyf_start = *out_offset;
FT_ULong dest_offset = *out_offset;
WOFF2_Substream substreams = NULL;
FT_ULong* loca_values = NULL;
FT_UShort* n_points_arr = NULL;
FT_Byte* glyph_buf = NULL;
WOFF2_Point points = NULL;
if ( FT_NEW_ARRAY( substreams, num_substreams ) )
goto Fail;
if ( FT_STREAM_SKIP( 2 ) )
goto Fail;
if ( FT_READ_USHORT( option_flags ) )
goto Fail;
if ( FT_READ_USHORT( num_glyphs ) )
goto Fail;
if ( FT_READ_USHORT( index_format ) )
goto Fail;
FT_TRACE4(( "option_flags = %u; num_glyphs = %u; index_format = %u\n",
option_flags, num_glyphs, index_format ));
info->num_glyphs = num_glyphs;
/* Calculate expected length of loca and compare. */
/* See https://www.w3.org/TR/WOFF2/#conform-mustRejectLoca */
/* index_format = 0 => Short version `loca'. */
/* index_format = 1 => Long version `loca'. */
expected_loca_length = ( index_format ? 4 : 2 ) *
( (FT_ULong)num_glyphs + 1 );
if ( info->loca_table->dst_length != expected_loca_length )
goto Fail;
offset = 2 + 2 + 2 + 2 + ( num_substreams * 4 );
if ( offset > info->glyf_table->TransformLength )
goto Fail;
for ( i = 0; i < num_substreams; ++i )
{
FT_ULong substream_size;
if ( FT_READ_ULONG( substream_size ) )
goto Fail;
if ( substream_size > info->glyf_table->TransformLength - offset )
goto Fail;
substreams[i].start = pos + offset;
substreams[i].offset = pos + offset;
substreams[i].size = substream_size;
FT_TRACE5(( " Substream %d: offset = %lu; size = %lu;\n",
i, substreams[i].offset, substreams[i].size ));
offset += substream_size;
}
if ( option_flags & HAVE_OVERLAP_SIMPLE_BITMAP )
{
/* Size of overlapBitmap = floor((numGlyphs + 7) / 8) */
overlap_bitmap_length = ( num_glyphs + 7U ) >> 3;
if ( overlap_bitmap_length > info->glyf_table->TransformLength - offset )
goto Fail;
overlap_bitmap_offset = pos + offset;
FT_TRACE5(( " Overlap bitmap: offset = %lu; size = %lu;\n",
overlap_bitmap_offset, overlap_bitmap_length ));
offset += overlap_bitmap_length;
}
if ( FT_NEW_ARRAY( loca_values, num_glyphs + 1 ) )
goto Fail;
points_size = 0;
bbox_bitmap_offset = substreams[BBOX_STREAM].offset;
/* Size of bboxBitmap = 4 * floor((numGlyphs + 31) / 32) */
bbox_bitmap_length = ( ( num_glyphs + 31U ) >> 5 ) << 2;
/* bboxStreamSize is the combined size of bboxBitmap and bboxStream. */
substreams[BBOX_STREAM].offset += bbox_bitmap_length;
glyph_buf_size = WOFF2_DEFAULT_GLYPH_BUF;
if ( FT_NEW_ARRAY( glyph_buf, glyph_buf_size ) )
goto Fail;
if ( FT_NEW_ARRAY( info->x_mins, num_glyphs ) )
goto Fail;
for ( i = 0; i < num_glyphs; ++i )
{
FT_ULong glyph_size = 0;
FT_UShort n_contours = 0;
FT_Bool have_bbox = FALSE;
FT_Byte bbox_bitmap;
FT_ULong bbox_offset;
FT_UShort x_min = 0;
/* Set `have_bbox'. */
bbox_offset = bbox_bitmap_offset + ( i >> 3 );
if ( FT_STREAM_SEEK( bbox_offset ) ||
FT_READ_BYTE( bbox_bitmap ) )
goto Fail;
if ( bbox_bitmap & ( 0x80 >> ( i & 7 ) ) )
have_bbox = TRUE;
/* Read value from `nContourStream'. */
if ( FT_STREAM_SEEK( substreams[N_CONTOUR_STREAM].offset ) ||
FT_READ_USHORT( n_contours ) )
goto Fail;
substreams[N_CONTOUR_STREAM].offset += 2;
if ( n_contours == 0xffff )
{
/* composite glyph */
FT_Bool have_instructions = FALSE;
FT_UShort instruction_size = 0;
FT_ULong composite_size;
FT_ULong size_needed;
FT_Byte* pointer = NULL;
/* Composite glyphs must have explicit bbox. */
if ( !have_bbox )
goto Fail;
if ( compositeGlyph_size( stream,
substreams[COMPOSITE_STREAM].offset,
&composite_size,
&have_instructions) )
goto Fail;
if ( have_instructions )
{
if ( FT_STREAM_SEEK( substreams[GLYPH_STREAM].offset ) ||
READ_255USHORT( instruction_size ) )
goto Fail;
substreams[GLYPH_STREAM].offset = FT_STREAM_POS();
}
size_needed = 12 + composite_size + instruction_size;
if ( glyph_buf_size < size_needed )
{
if ( FT_RENEW_ARRAY( glyph_buf, glyph_buf_size, size_needed ) )
goto Fail;
glyph_buf_size = size_needed;
}
pointer = glyph_buf + glyph_size;
WRITE_USHORT( pointer, n_contours );
glyph_size += 2;
/* Read x_min for current glyph. */
if ( FT_STREAM_SEEK( substreams[BBOX_STREAM].offset ) ||
FT_READ_USHORT( x_min ) )
goto Fail;
/* No increment here because we read again. */
if ( FT_STREAM_SEEK( substreams[BBOX_STREAM].offset ) ||
FT_STREAM_READ( glyph_buf + glyph_size, 8 ) )
goto Fail;
substreams[BBOX_STREAM].offset += 8;
glyph_size += 8;
if ( FT_STREAM_SEEK( substreams[COMPOSITE_STREAM].offset ) ||
FT_STREAM_READ( glyph_buf + glyph_size, composite_size ) )
goto Fail;
substreams[COMPOSITE_STREAM].offset += composite_size;
glyph_size += composite_size;
if ( have_instructions )
{
pointer = glyph_buf + glyph_size;
WRITE_USHORT( pointer, instruction_size );
glyph_size += 2;
if ( FT_STREAM_SEEK( substreams[INSTRUCTION_STREAM].offset ) ||
FT_STREAM_READ( glyph_buf + glyph_size, instruction_size ) )
goto Fail;
substreams[INSTRUCTION_STREAM].offset += instruction_size;
glyph_size += instruction_size;
}
}
else if ( n_contours > 0 )
{
/* simple glyph */
FT_ULong total_n_points = 0;
FT_UShort n_points_contour;
FT_UInt j;
FT_ULong flag_size;
FT_ULong triplet_size;
FT_ULong triplet_bytes_used;
FT_Bool have_overlap = FALSE;
FT_Byte overlap_bitmap;
FT_ULong overlap_offset;
FT_Byte* flags_buf = NULL;
FT_Byte* triplet_buf = NULL;
FT_UShort instruction_size;
FT_ULong size_needed;
FT_Int end_point;
FT_UInt contour_ix;
FT_Byte* pointer = NULL;
/* Set `have_overlap`. */
if ( overlap_bitmap_offset )
{
overlap_offset = overlap_bitmap_offset + ( i >> 3 );
if ( FT_STREAM_SEEK( overlap_offset ) ||
FT_READ_BYTE( overlap_bitmap ) )
goto Fail;
if ( overlap_bitmap & ( 0x80 >> ( i & 7 ) ) )
have_overlap = TRUE;
}
if ( FT_NEW_ARRAY( n_points_arr, n_contours ) )
goto Fail;
if ( FT_STREAM_SEEK( substreams[N_POINTS_STREAM].offset ) )
goto Fail;
for ( j = 0; j < n_contours; ++j )
{
if ( READ_255USHORT( n_points_contour ) )
goto Fail;
n_points_arr[j] = n_points_contour;
/* Prevent negative/overflow. */
if ( total_n_points + n_points_contour < total_n_points )
goto Fail;
total_n_points += n_points_contour;
}
substreams[N_POINTS_STREAM].offset = FT_STREAM_POS();
flag_size = total_n_points;
if ( flag_size > substreams[FLAG_STREAM].size )
goto Fail;
flags_buf = stream->base + substreams[FLAG_STREAM].offset;
triplet_buf = stream->base + substreams[GLYPH_STREAM].offset;
if ( substreams[GLYPH_STREAM].size <
( substreams[GLYPH_STREAM].offset -
substreams[GLYPH_STREAM].start ) )
goto Fail;
triplet_size = substreams[GLYPH_STREAM].size -
( substreams[GLYPH_STREAM].offset -
substreams[GLYPH_STREAM].start );
triplet_bytes_used = 0;
/* Create array to store point information. */
points_size = total_n_points;
if ( FT_NEW_ARRAY( points, points_size ) )
goto Fail;
if ( triplet_decode( flags_buf,
triplet_buf,
triplet_size,
total_n_points,
points,
&triplet_bytes_used ) )
goto Fail;
substreams[FLAG_STREAM].offset += flag_size;
substreams[GLYPH_STREAM].offset += triplet_bytes_used;
if ( FT_STREAM_SEEK( substreams[GLYPH_STREAM].offset ) ||
READ_255USHORT( instruction_size ) )
goto Fail;
substreams[GLYPH_STREAM].offset = FT_STREAM_POS();
if ( total_n_points >= ( 1 << 27 ) )
goto Fail;
size_needed = 12 +
( 2 * n_contours ) +
( 5 * total_n_points ) +
instruction_size;
if ( glyph_buf_size < size_needed )
{
if ( FT_RENEW_ARRAY( glyph_buf, glyph_buf_size, size_needed ) )
goto Fail;
glyph_buf_size = size_needed;
}
pointer = glyph_buf + glyph_size;
WRITE_USHORT( pointer, n_contours );
glyph_size += 2;
if ( have_bbox )
{
/* Read x_min for current glyph. */
if ( FT_STREAM_SEEK( substreams[BBOX_STREAM].offset ) ||
FT_READ_USHORT( x_min ) )
goto Fail;
/* No increment here because we read again. */
if ( FT_STREAM_SEEK( substreams[BBOX_STREAM].offset ) ||
FT_STREAM_READ( glyph_buf + glyph_size, 8 ) )
goto Fail;
substreams[BBOX_STREAM].offset += 8;
}
else
compute_bbox( total_n_points, points, glyph_buf, &x_min );
glyph_size = CONTOUR_OFFSET_END_POINT;
pointer = glyph_buf + glyph_size;
end_point = -1;
for ( contour_ix = 0; contour_ix < n_contours; ++contour_ix )
{
end_point += n_points_arr[contour_ix];
if ( end_point >= 65536 )
goto Fail;
WRITE_SHORT( pointer, end_point );
glyph_size += 2;
}
WRITE_USHORT( pointer, instruction_size );
glyph_size += 2;
if ( FT_STREAM_SEEK( substreams[INSTRUCTION_STREAM].offset ) ||
FT_STREAM_READ( glyph_buf + glyph_size, instruction_size ) )
goto Fail;
substreams[INSTRUCTION_STREAM].offset += instruction_size;
glyph_size += instruction_size;
if ( store_points( total_n_points,
points,
n_contours,
instruction_size,
have_overlap,
glyph_buf,
glyph_buf_size,
&glyph_size ) )
goto Fail;
FT_FREE( points );
FT_FREE( n_points_arr );
}
else
{
/* Empty glyph. */
/* Must not have a bbox. */
if ( have_bbox )
{
FT_ERROR(( "Empty glyph has a bbox.\n" ));
goto Fail;
}
}
loca_values[i] = dest_offset - glyf_start;
if ( WRITE_SFNT_BUF( glyph_buf, glyph_size ) )
goto Fail;
if ( pad4( &sfnt, sfnt_size, &dest_offset, memory ) )
goto Fail;
*glyf_checksum += compute_ULong_sum( glyph_buf, glyph_size );
/* Store x_mins, may be required to reconstruct `hmtx'. */
if ( n_contours > 0 )
info->x_mins[i] = (FT_Short)x_min;
}
info->glyf_table->dst_length = dest_offset - info->glyf_table->dst_offset;
info->loca_table->dst_offset = dest_offset;
/* `loca[n]' will be equal to the length of the `glyf' table. */
loca_values[num_glyphs] = info->glyf_table->dst_length;
if ( store_loca( loca_values,
num_glyphs + 1,
index_format,
loca_checksum,
&sfnt,
sfnt_size,
&dest_offset,
memory ) )
goto Fail;
info->loca_table->dst_length = dest_offset - info->loca_table->dst_offset;
FT_TRACE4(( " loca table info:\n" ));
FT_TRACE4(( " dst_offset = %lu\n", info->loca_table->dst_offset ));
FT_TRACE4(( " dst_length = %lu\n", info->loca_table->dst_length ));
FT_TRACE4(( " checksum = %09lx\n", *loca_checksum ));
/* Set pointer `sfnt_bytes' to its correct value. */
*sfnt_bytes = sfnt;
*out_offset = dest_offset;
FT_FREE( substreams );
FT_FREE( loca_values );
FT_FREE( n_points_arr );
FT_FREE( glyph_buf );
FT_FREE( points );
return error;
Fail:
if ( !error )
error = FT_THROW( Invalid_Table );
/* Set pointer `sfnt_bytes' to its correct value. */
*sfnt_bytes = sfnt;
FT_FREE( substreams );
FT_FREE( loca_values );
FT_FREE( n_points_arr );
FT_FREE( glyph_buf );
FT_FREE( points );
return error;
}
/* Get `x_mins' for untransformed `glyf' table. */
static FT_Error
get_x_mins( FT_Stream stream,
WOFF2_Table* tables,
FT_UShort num_tables,
WOFF2_Info info,
FT_Memory memory )
{
FT_UShort num_glyphs;
FT_UShort index_format;
FT_ULong glyf_offset;
FT_UShort glyf_offset_short;
FT_ULong loca_offset;
FT_Int i;
FT_Error error = FT_Err_Ok;
FT_ULong offset_size;
/* At this point of time those tables might not have been read yet. */
const WOFF2_Table maxp_table = find_table( tables, num_tables,
TTAG_maxp );
const WOFF2_Table head_table = find_table( tables, num_tables,
TTAG_head );
if ( !maxp_table )
{
FT_ERROR(( "`maxp' table is missing.\n" ));
return FT_THROW( Invalid_Table );
}
if ( !head_table )
{
FT_ERROR(( "`head' table is missing.\n" ));
return FT_THROW( Invalid_Table );
}
if ( !info->loca_table )
{
FT_ERROR(( "`loca' table is missing.\n" ));
return FT_THROW( Invalid_Table );
}
/* Read `numGlyphs' field from `maxp' table. */
if ( FT_STREAM_SEEK( maxp_table->src_offset ) || FT_STREAM_SKIP( 8 ) )
return error;
if ( FT_READ_USHORT( num_glyphs ) )
return error;
info->num_glyphs = num_glyphs;
/* Read `indexToLocFormat' field from `head' table. */
if ( FT_STREAM_SEEK( head_table->src_offset ) ||
FT_STREAM_SKIP( 50 ) )
return error;
if ( FT_READ_USHORT( index_format ) )
return error;
offset_size = index_format ? 4 : 2;
/* Create `x_mins' array. */
if ( FT_NEW_ARRAY( info->x_mins, num_glyphs ) )
return error;
loca_offset = info->loca_table->src_offset;
for ( i = 0; i < num_glyphs; ++i )
{
if ( FT_STREAM_SEEK( loca_offset ) )
return error;
loca_offset += offset_size;
if ( index_format )
{
if ( FT_READ_ULONG( glyf_offset ) )
return error;
}
else
{
if ( FT_READ_USHORT( glyf_offset_short ) )
return error;
glyf_offset = (FT_ULong)( glyf_offset_short );
glyf_offset = glyf_offset << 1;
}
glyf_offset += info->glyf_table->src_offset;
if ( FT_STREAM_SEEK( glyf_offset ) || FT_STREAM_SKIP( 2 ) )
return error;
if ( FT_READ_SHORT( info->x_mins[i] ) )
return error;
}
return error;
}
static FT_Error
reconstruct_hmtx( FT_Stream stream,
FT_UShort num_glyphs,
FT_UShort num_hmetrics,
FT_Short* x_mins,
FT_ULong* checksum,
FT_Byte** sfnt_bytes,
FT_ULong* sfnt_size,
FT_ULong* out_offset,
FT_Memory memory )
{
FT_Error error = FT_Err_Ok;
FT_Byte* sfnt = *sfnt_bytes;
FT_ULong dest_offset = *out_offset;
FT_Byte hmtx_flags;
FT_Bool has_proportional_lsbs, has_monospace_lsbs;
FT_ULong hmtx_table_size;
FT_Int i;
FT_UShort* advance_widths = NULL;
FT_Short* lsbs = NULL;
FT_Byte* hmtx_table = NULL;
FT_Byte* dst = NULL;
if ( FT_READ_BYTE( hmtx_flags ) )
goto Fail;
has_proportional_lsbs = ( hmtx_flags & 1 ) == 0;
has_monospace_lsbs = ( hmtx_flags & 2 ) == 0;
/* Bits 2-7 are reserved and MUST be zero. */
if ( ( hmtx_flags & 0xFC ) != 0 )
goto Fail;
/* Are you REALLY transformed? */
if ( has_proportional_lsbs && has_monospace_lsbs )
goto Fail;
/* Cannot have a transformed `hmtx' without `glyf'. */
if ( ( num_hmetrics > num_glyphs ) ||
( num_hmetrics < 1 ) )
goto Fail;
/* Must have at least one entry. */
if ( num_hmetrics < 1 )
goto Fail;
if ( FT_NEW_ARRAY( advance_widths, num_hmetrics ) ||
FT_NEW_ARRAY( lsbs, num_glyphs ) )
goto Fail;
/* Read `advanceWidth' stream. Always present. */
for ( i = 0; i < num_hmetrics; i++ )
{
FT_UShort advance_width;
if ( FT_READ_USHORT( advance_width ) )
goto Fail;
advance_widths[i] = advance_width;
}
/* lsb values for proportional glyphs. */
for ( i = 0; i < num_hmetrics; i++ )
{
FT_Short lsb;
if ( has_proportional_lsbs )
{
if ( FT_READ_SHORT( lsb ) )
goto Fail;
}
else
lsb = x_mins[i];
lsbs[i] = lsb;
}
/* lsb values for monospaced glyphs. */
for ( i = num_hmetrics; i < num_glyphs; i++ )
{
FT_Short lsb;
if ( has_monospace_lsbs )
{
if ( FT_READ_SHORT( lsb ) )
goto Fail;
}
else
lsb = x_mins[i];
lsbs[i] = lsb;
}
/* Build the hmtx table. */
hmtx_table_size = 2 * num_hmetrics + 2 * num_glyphs;
if ( FT_NEW_ARRAY( hmtx_table, hmtx_table_size ) )
goto Fail;
dst = hmtx_table;
FT_TRACE6(( "hmtx values: \n" ));
for ( i = 0; i < num_glyphs; i++ )
{
if ( i < num_hmetrics )
{
WRITE_SHORT( dst, advance_widths[i] );
FT_TRACE6(( "%d ", advance_widths[i] ));
}
WRITE_SHORT( dst, lsbs[i] );
FT_TRACE6(( "%d ", lsbs[i] ));
}
FT_TRACE6(( "\n" ));
*checksum = compute_ULong_sum( hmtx_table, hmtx_table_size );
/* Write `hmtx' table to sfnt buffer. */
if ( WRITE_SFNT_BUF( hmtx_table, hmtx_table_size ) )
goto Fail;
/* Set pointer `sfnt_bytes' to its correct value. */
*sfnt_bytes = sfnt;
*out_offset = dest_offset;
FT_FREE( advance_widths );
FT_FREE( lsbs );
FT_FREE( hmtx_table );
return error;
Fail:
FT_FREE( advance_widths );
FT_FREE( lsbs );
FT_FREE( hmtx_table );
if ( !error )
error = FT_THROW( Invalid_Table );
return error;
}
static FT_Error
reconstruct_font( FT_Byte* transformed_buf,
FT_ULong transformed_buf_size,
WOFF2_Table* indices,
WOFF2_Header woff2,
WOFF2_Info info,
FT_Byte** sfnt_bytes,
FT_ULong* sfnt_size,
FT_Memory memory )
{
/* Memory management of `transformed_buf' is handled by the caller. */
FT_Error error = FT_Err_Ok;
FT_Stream stream = NULL;
FT_Byte* buf_cursor = NULL;
FT_Byte* table_entry = NULL;
/* We are reallocating memory for `sfnt', so its pointer may change. */
FT_Byte* sfnt = *sfnt_bytes;
FT_UShort num_tables = woff2->num_tables;
FT_ULong dest_offset = 12 + num_tables * 16UL;
FT_ULong checksum = 0;
FT_ULong loca_checksum = 0;
FT_Int nn = 0;
FT_UShort num_hmetrics = 0;
FT_ULong font_checksum = info->header_checksum;
FT_Bool is_glyf_xform = FALSE;
FT_ULong table_entry_offset = 12;
/* A few table checks before reconstruction. */
/* `glyf' must be present with `loca'. */
info->glyf_table = find_table( indices, num_tables, TTAG_glyf );
info->loca_table = find_table( indices, num_tables, TTAG_loca );
if ( ( info->glyf_table == NULL ) ^ ( info->loca_table == NULL ) )
{
FT_ERROR(( "One of `glyf'/`loca' tables missing.\n" ));
return FT_THROW( Invalid_Table );
}
/* Both `glyf' and `loca' must have same transformation. */
if ( info->glyf_table != NULL )
{
if ( ( info->glyf_table->flags & WOFF2_FLAGS_TRANSFORM ) !=
( info->loca_table->flags & WOFF2_FLAGS_TRANSFORM ) )
{
FT_ERROR(( "Transformation mismatch"
" between `glyf' and `loca' table." ));
return FT_THROW( Invalid_Table );
}
}
/* Create buffer for table entries. */
if ( FT_NEW_ARRAY( table_entry, 16 ) )
goto Fail;
/* Create a stream for the uncompressed buffer. */
if ( FT_NEW( stream ) )
goto Fail;
FT_Stream_OpenMemory( stream, transformed_buf, transformed_buf_size );
FT_ASSERT( FT_STREAM_POS() == 0 );
/* Reconstruct/copy tables to output stream. */
for ( nn = 0; nn < num_tables; nn++ )
{
WOFF2_TableRec table = *( indices[nn] );
FT_TRACE3(( "Seeking to %ld with table size %ld.\n",
table.src_offset, table.src_length ));
FT_TRACE3(( "Table tag: %c%c%c%c.\n",
(FT_Char)( table.Tag >> 24 ),
(FT_Char)( table.Tag >> 16 ),
(FT_Char)( table.Tag >> 8 ),
(FT_Char)( table.Tag ) ));
if ( FT_STREAM_SEEK( table.src_offset ) )
goto Fail;
if ( table.src_offset + table.src_length > transformed_buf_size )
goto Fail;
/* Get stream size for fields of `hmtx' table. */
if ( table.Tag == TTAG_hhea )
{
if ( read_num_hmetrics( stream, &num_hmetrics ) )
goto Fail;
}
info->num_hmetrics = num_hmetrics;
checksum = 0;
if ( ( table.flags & WOFF2_FLAGS_TRANSFORM ) != WOFF2_FLAGS_TRANSFORM )
{
/* Check whether `head' is at least 12 bytes. */
if ( table.Tag == TTAG_head )
{
if ( table.src_length < 12 )
goto Fail;
buf_cursor = transformed_buf + table.src_offset + 8;
/* Set checkSumAdjustment = 0 */
WRITE_ULONG( buf_cursor, 0 );
}
table.dst_offset = dest_offset;
checksum = compute_ULong_sum( transformed_buf + table.src_offset,
table.src_length );
FT_TRACE4(( "Checksum = %09lx.\n", checksum ));
if ( WRITE_SFNT_BUF( transformed_buf + table.src_offset,
table.src_length ) )
goto Fail;
}
else
{
FT_TRACE3(( "This table is transformed.\n" ));
if ( table.Tag == TTAG_glyf )
{
is_glyf_xform = TRUE;
table.dst_offset = dest_offset;
if ( reconstruct_glyf( stream,
&checksum,
&loca_checksum,
&sfnt,
sfnt_size,
&dest_offset,
info,
memory ) )
goto Fail;
FT_TRACE4(( "Checksum = %09lx.\n", checksum ));
}
else if ( table.Tag == TTAG_loca )
checksum = loca_checksum;
else if ( table.Tag == TTAG_hmtx )
{
/* If glyf is not transformed and hmtx is, handle separately. */
if ( !is_glyf_xform )
{
if ( get_x_mins( stream, indices, num_tables, info, memory ) )
goto Fail;
}
table.dst_offset = dest_offset;
if ( reconstruct_hmtx( stream,
info->num_glyphs,
info->num_hmetrics,
info->x_mins,
&checksum,
&sfnt,
sfnt_size,
&dest_offset,
memory ) )
goto Fail;
}
else
{
/* Unknown transform. */
FT_ERROR(( "Unknown table transform.\n" ));
goto Fail;
}
}
font_checksum += checksum;
buf_cursor = &table_entry[0];
WRITE_ULONG( buf_cursor, table.Tag );
WRITE_ULONG( buf_cursor, checksum );
WRITE_ULONG( buf_cursor, table.dst_offset );
WRITE_ULONG( buf_cursor, table.dst_length );
WRITE_SFNT_BUF_AT( table_entry_offset, table_entry, 16 );
/* Update checksum. */
font_checksum += compute_ULong_sum( table_entry, 16 );
if ( pad4( &sfnt, sfnt_size, &dest_offset, memory ) )
goto Fail;
/* Sanity check. */
if ( (FT_ULong)( table.dst_offset + table.dst_length ) > dest_offset )
{
FT_ERROR(( "Table was partially written.\n" ));
goto Fail;
}
}
/* Update `head' checkSumAdjustment. */
info->head_table = find_table( indices, num_tables, TTAG_head );
if ( !info->head_table )
{
FT_ERROR(( "`head' table is missing.\n" ));
goto Fail;
}
if ( info->head_table->dst_length < 12 )
goto Fail;
buf_cursor = sfnt + info->head_table->dst_offset + 8;
font_checksum = 0xB1B0AFBA - font_checksum;
WRITE_ULONG( buf_cursor, font_checksum );
FT_TRACE2(( "Final checksum = %09lx.\n", font_checksum ));
woff2->actual_sfnt_size = dest_offset;
/* Set pointer of sfnt stream to its correct value. */
*sfnt_bytes = sfnt;
FT_FREE( table_entry );
FT_Stream_Close( stream );
FT_FREE( stream );
return error;
Fail:
if ( !error )
error = FT_THROW( Invalid_Table );
/* Set pointer of sfnt stream to its correct value. */
*sfnt_bytes = sfnt;
FT_FREE( table_entry );
FT_Stream_Close( stream );
FT_FREE( stream );
return error;
}
/* Replace `face->root.stream' with a stream containing the extracted */
/* SFNT of a WOFF2 font. */
FT_LOCAL_DEF( FT_Error )
woff2_open_font( FT_Stream stream,
TT_Face face,
FT_Int* face_instance_index,
FT_Long* num_faces )
{
FT_Memory memory = stream->memory;
FT_Error error = FT_Err_Ok;
FT_Int face_index;
WOFF2_HeaderRec woff2;
WOFF2_InfoRec info = { 0, 0, 0, NULL, NULL, NULL, NULL };
WOFF2_Table tables = NULL;
WOFF2_Table* indices = NULL;
WOFF2_Table* temp_indices = NULL;
WOFF2_Table last_table;
FT_Int nn;
FT_ULong j;
FT_ULong flags;
FT_UShort xform_version;
FT_ULong src_offset = 0;
FT_UInt glyf_index;
FT_UInt loca_index;
FT_UInt32 file_offset;
FT_Byte* sfnt = NULL;
FT_Stream sfnt_stream = NULL;
FT_Byte* sfnt_header;
FT_ULong sfnt_size;
FT_Byte* uncompressed_buf = NULL;
static const FT_Frame_Field woff2_header_fields[] =
{
#undef FT_STRUCTURE
#define FT_STRUCTURE WOFF2_HeaderRec
FT_FRAME_START( 48 ),
FT_FRAME_ULONG ( signature ),
FT_FRAME_ULONG ( flavor ),
FT_FRAME_ULONG ( length ),
FT_FRAME_USHORT ( num_tables ),
FT_FRAME_SKIP_BYTES( 2 ),
FT_FRAME_ULONG ( totalSfntSize ),
FT_FRAME_ULONG ( totalCompressedSize ),
FT_FRAME_SKIP_BYTES( 2 * 2 ),
FT_FRAME_ULONG ( metaOffset ),
FT_FRAME_ULONG ( metaLength ),
FT_FRAME_ULONG ( metaOrigLength ),
FT_FRAME_ULONG ( privOffset ),
FT_FRAME_ULONG ( privLength ),
FT_FRAME_END
};
FT_ASSERT( stream == face->root.stream );
FT_ASSERT( FT_STREAM_POS() == 0 );
face_index = FT_ABS( *face_instance_index ) & 0xFFFF;
/* Read WOFF2 Header. */
if ( FT_STREAM_READ_FIELDS( woff2_header_fields, &woff2 ) )
return error;
FT_TRACE4(( "signature -> 0x%lX\n", woff2.signature ));
FT_TRACE2(( "flavor -> 0x%08lx\n", woff2.flavor ));
FT_TRACE4(( "length -> %lu\n", woff2.length ));
FT_TRACE2(( "num_tables -> %hu\n", woff2.num_tables ));
FT_TRACE4(( "totalSfntSize -> %lu\n", woff2.totalSfntSize ));
FT_TRACE4(( "metaOffset -> %lu\n", woff2.metaOffset ));
FT_TRACE4(( "metaLength -> %lu\n", woff2.metaLength ));
FT_TRACE4(( "privOffset -> %lu\n", woff2.privOffset ));
FT_TRACE4(( "privLength -> %lu\n", woff2.privLength ));
/* Make sure we don't recurse back here. */
if ( woff2.flavor == TTAG_wOF2 )
return FT_THROW( Invalid_Table );
/* Miscellaneous checks. */
if ( woff2.length != stream->size ||
woff2.num_tables == 0 ||
48 + woff2.num_tables * 20UL >= woff2.length ||
( woff2.metaOffset == 0 && ( woff2.metaLength != 0 ||
woff2.metaOrigLength != 0 ) ) ||
( woff2.metaLength != 0 && woff2.metaOrigLength == 0 ) ||
( woff2.metaOffset >= woff2.length ) ||
( woff2.length - woff2.metaOffset < woff2.metaLength ) ||
( woff2.privOffset == 0 && woff2.privLength != 0 ) ||
( woff2.privOffset >= woff2.length ) ||
( woff2.length - woff2.privOffset < woff2.privLength ) )
{
FT_ERROR(( "woff2_open_font: invalid WOFF2 header\n" ));
return FT_THROW( Invalid_Table );
}
FT_TRACE2(( "woff2_open_font: WOFF2 Header is valid.\n" ));
woff2.ttc_fonts = NULL;
/* Read table directory. */
if ( FT_NEW_ARRAY( tables, woff2.num_tables ) ||
FT_NEW_ARRAY( indices, woff2.num_tables ) )
goto Exit;
FT_TRACE2(( "\n" ));
FT_TRACE2(( " tag flags transform origLen transformLen offset\n" ));
FT_TRACE2(( " -----------------------------------------------------------\n" ));
/* " XXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX" */
for ( nn = 0; nn < woff2.num_tables; nn++ )
{
WOFF2_Table table = tables + nn;
if ( FT_READ_BYTE( table->FlagByte ) )
goto Exit;
if ( ( table->FlagByte & 0x3f ) == 0x3f )
{
if ( FT_READ_ULONG( table->Tag ) )
goto Exit;
}
else
{
table->Tag = woff2_known_tags( table->FlagByte & 0x3f );
if ( !table->Tag )
{
FT_ERROR(( "woff2_open_font: Unknown table tag." ));
error = FT_THROW( Invalid_Table );
goto Exit;
}
}
flags = 0;
xform_version = ( table->FlagByte >> 6 ) & 0x03;
/* 0 means xform for glyph/loca, non-0 for others. */
if ( table->Tag == TTAG_glyf || table->Tag == TTAG_loca )
{
if ( xform_version == 0 )
flags |= WOFF2_FLAGS_TRANSFORM;
}
else if ( xform_version != 0 )
flags |= WOFF2_FLAGS_TRANSFORM;
flags |= xform_version;
if ( READ_BASE128( table->dst_length ) )
goto Exit;
table->TransformLength = table->dst_length;
if ( ( flags & WOFF2_FLAGS_TRANSFORM ) != 0 )
{
if ( READ_BASE128( table->TransformLength ) )
goto Exit;
if ( table->Tag == TTAG_loca && table->TransformLength )
{
FT_ERROR(( "woff2_open_font: Invalid loca `transformLength'.\n" ));
error = FT_THROW( Invalid_Table );
goto Exit;
}
}
if ( src_offset + table->TransformLength < src_offset )
{
FT_ERROR(( "woff2_open_font: invalid WOFF2 table directory.\n" ));
error = FT_THROW( Invalid_Table );
goto Exit;
}
table->src_offset = src_offset;
table->src_length = table->TransformLength;
src_offset += table->TransformLength;
table->flags = flags;
FT_TRACE2(( " %c%c%c%c %08d %08d %08ld %08ld %08ld\n",
(FT_Char)( table->Tag >> 24 ),
(FT_Char)( table->Tag >> 16 ),
(FT_Char)( table->Tag >> 8 ),
(FT_Char)( table->Tag ),
table->FlagByte & 0x3f,
( table->FlagByte >> 6 ) & 0x03,
table->dst_length,
table->TransformLength,
table->src_offset ));
indices[nn] = table;
}
/* End of last table is uncompressed size. */
last_table = indices[woff2.num_tables - 1];
woff2.uncompressed_size = last_table->src_offset +
last_table->src_length;
if ( woff2.uncompressed_size < last_table->src_offset )
{
error = FT_THROW( Invalid_Table );
goto Exit;
}
FT_TRACE2(( "Table directory parsed.\n" ));
/* Check for and read collection directory. */
woff2.num_fonts = 1;
woff2.header_version = 0;
if ( woff2.flavor == TTAG_ttcf )
{
FT_TRACE2(( "Font is a TTC, reading collection directory.\n" ));
if ( FT_READ_ULONG( woff2.header_version ) )
goto Exit;
if ( woff2.header_version != 0x00010000 &&
woff2.header_version != 0x00020000 )
{
error = FT_THROW( Invalid_Table );
goto Exit;
}
if ( READ_255USHORT( woff2.num_fonts ) )
goto Exit;
if ( !woff2.num_fonts )
{
error = FT_THROW( Invalid_Table );
goto Exit;
}
FT_TRACE4(( "Number of fonts in TTC: %d\n", woff2.num_fonts ));
if ( FT_NEW_ARRAY( woff2.ttc_fonts, woff2.num_fonts ) )
goto Exit;
for ( nn = 0; nn < woff2.num_fonts; nn++ )
{
WOFF2_TtcFont ttc_font = woff2.ttc_fonts + nn;
if ( READ_255USHORT( ttc_font->num_tables ) )
goto Exit;
if ( FT_READ_ULONG( ttc_font->flavor ) )
goto Exit;
if ( FT_NEW_ARRAY( ttc_font->table_indices, ttc_font->num_tables ) )
goto Exit;
FT_TRACE5(( "Number of tables in font %d: %d\n",
nn, ttc_font->num_tables ));
#ifdef FT_DEBUG_LEVEL_TRACE
if ( ttc_font->num_tables )
FT_TRACE6(( " Indices: " ));
#endif
glyf_index = 0;
loca_index = 0;
for ( j = 0; j < ttc_font->num_tables; j++ )
{
FT_UShort table_index;
WOFF2_Table table;
if ( READ_255USHORT( table_index ) )
goto Exit;
FT_TRACE6(( "%hu ", table_index ));
if ( table_index >= woff2.num_tables )
{
FT_ERROR(( "woff2_open_font: invalid table index\n" ));
error = FT_THROW( Invalid_Table );
goto Exit;
}
ttc_font->table_indices[j] = table_index;
table = indices[table_index];
if ( table->Tag == TTAG_loca )
loca_index = table_index;
if ( table->Tag == TTAG_glyf )
glyf_index = table_index;
}
#ifdef FT_DEBUG_LEVEL_TRACE
if ( ttc_font->num_tables )
FT_TRACE6(( "\n" ));
#endif
/* glyf and loca must be consecutive */
if ( glyf_index > 0 || loca_index > 0 )
{
if ( glyf_index > loca_index ||
loca_index - glyf_index != 1 )
{
error = FT_THROW( Invalid_Table );
goto Exit;
}
}
}
/* Collection directory reading complete. */
FT_TRACE2(( "WOFF2 collection directory is valid.\n" ));
}
else
woff2.ttc_fonts = NULL;
woff2.compressed_offset = FT_STREAM_POS();
file_offset = ROUND4( woff2.compressed_offset +
woff2.totalCompressedSize );
/* Some more checks before we start reading the tables. */
if ( file_offset > woff2.length )
{
error = FT_THROW( Invalid_Table );
goto Exit;
}
if ( woff2.metaOffset )
{
if ( file_offset != woff2.metaOffset )
{
error = FT_THROW( Invalid_Table );
goto Exit;
}
file_offset = ROUND4(woff2.metaOffset + woff2.metaLength);
}
if ( woff2.privOffset )
{
if ( file_offset != woff2.privOffset )
{
error = FT_THROW( Invalid_Table );
goto Exit;
}
file_offset = ROUND4(woff2.privOffset + woff2.privLength);
}
if ( file_offset != ( ROUND4( woff2.length ) ) )
{
error = FT_THROW( Invalid_Table );
goto Exit;
}
/* Validate requested face index. */
*num_faces = woff2.num_fonts;
/* value -(N+1) requests information on index N */
if ( *face_instance_index < 0 && face_index > 0 )
face_index--;
if ( face_index >= woff2.num_fonts )
{
if ( *face_instance_index >= 0 )
{
error = FT_THROW( Invalid_Argument );
goto Exit;
}
else
face_index = 0;
}
/* Only retain tables of the requested face in a TTC. */
if ( woff2.header_version )
{
WOFF2_TtcFont ttc_font = woff2.ttc_fonts + face_index;
/* Create a temporary array. */
if ( FT_QNEW_ARRAY( temp_indices,
ttc_font->num_tables ) )
goto Exit;
FT_TRACE4(( "Storing tables for TTC face index %d.\n", face_index ));
for ( nn = 0; nn < ttc_font->num_tables; nn++ )
temp_indices[nn] = indices[ttc_font->table_indices[nn]];
/* Resize array to required size. */
if ( FT_QRENEW_ARRAY( indices,
woff2.num_tables,
ttc_font->num_tables ) )
goto Exit;
for ( nn = 0; nn < ttc_font->num_tables; nn++ )
indices[nn] = temp_indices[nn];
FT_FREE( temp_indices );
/* Change header values. */
woff2.flavor = ttc_font->flavor;
woff2.num_tables = ttc_font->num_tables;
}
/* We need to allocate this much at the minimum. */
sfnt_size = 12 + woff2.num_tables * 16UL;
/* This is what we normally expect. */
/* Initially trust `totalSfntSize' and change later as required. */
if ( woff2.totalSfntSize > sfnt_size )
{
/* However, adjust the value to something reasonable. */
/* Factor 64 is heuristic. */
if ( ( woff2.totalSfntSize >> 6 ) > woff2.length )
sfnt_size = woff2.length << 6;
else
sfnt_size = woff2.totalSfntSize;
/* Value 1<<26 = 67108864 is heuristic. */
if (sfnt_size >= (1 << 26))
sfnt_size = 1 << 26;
#ifdef FT_DEBUG_LEVEL_TRACE
if ( sfnt_size != woff2.totalSfntSize )
FT_TRACE4(( "adjusting estimate of uncompressed font size"
" to %lu bytes\n",
sfnt_size ));
#endif
}
/* Write sfnt header. */
if ( FT_QALLOC( sfnt, sfnt_size ) ||
FT_NEW( sfnt_stream ) )
goto Exit;
sfnt_header = sfnt;
WRITE_ULONG( sfnt_header, woff2.flavor );
if ( woff2.num_tables )
{
FT_UInt searchRange, entrySelector, rangeShift, x;
x = woff2.num_tables;
entrySelector = 0;
while ( x )
{
x >>= 1;
entrySelector += 1;
}
entrySelector--;
searchRange = ( 1 << entrySelector ) * 16;
rangeShift = ( woff2.num_tables * 16 ) - searchRange;
WRITE_USHORT( sfnt_header, woff2.num_tables );
WRITE_USHORT( sfnt_header, searchRange );
WRITE_USHORT( sfnt_header, entrySelector );
WRITE_USHORT( sfnt_header, rangeShift );
}
info.header_checksum = compute_ULong_sum( sfnt, 12 );
/* Sort tables by tag. */
ft_qsort( indices,
woff2.num_tables,
sizeof ( WOFF2_Table ),
compare_tags );
/* reject fonts that have multiple tables with the same tag */
for ( nn = 1; nn < woff2.num_tables; nn++ )
{
FT_Tag tag = indices[nn]->Tag;
if ( tag == indices[nn - 1]->Tag )
{
FT_ERROR(( "woff2_open_font:"
" multiple tables with tag `%c%c%c%c'.\n",
(FT_Char)( tag >> 24 ),
(FT_Char)( tag >> 16 ),
(FT_Char)( tag >> 8 ),
(FT_Char)( tag ) ));
error = FT_THROW( Invalid_Table );
goto Exit;
}
}
if ( woff2.uncompressed_size < 1 )
{
error = FT_THROW( Invalid_Table );
goto Exit;
}
if ( woff2.uncompressed_size > sfnt_size )
{
FT_ERROR(( "woff2_open_font: SFNT table lengths are too large.\n" ));
error = FT_THROW( Invalid_Table );
goto Exit;
}
/* Allocate memory for uncompressed table data. */
if ( FT_QALLOC( uncompressed_buf, woff2.uncompressed_size ) ||
FT_FRAME_ENTER( woff2.totalCompressedSize ) )
goto Exit;
/* Uncompress the stream. */
error = woff2_decompress( uncompressed_buf,
woff2.uncompressed_size,
stream->cursor,
woff2.totalCompressedSize );
FT_FRAME_EXIT();
if ( error )
goto Exit;
error = reconstruct_font( uncompressed_buf,
woff2.uncompressed_size,
indices,
&woff2,
&info,
&sfnt,
&sfnt_size,
memory );
if ( error )
goto Exit;
/* Resize `sfnt' to actual size of sfnt stream. */
if ( woff2.actual_sfnt_size < sfnt_size )
{
FT_TRACE5(( "Trimming sfnt stream from %lu to %lu.\n",
sfnt_size, woff2.actual_sfnt_size ));
if ( FT_REALLOC( sfnt,
(FT_ULong)( sfnt_size ),
(FT_ULong)( woff2.actual_sfnt_size ) ) )
goto Exit;
}
/* `reconstruct_font' has done all the work. */
/* Swap out stream and return. */
FT_Stream_OpenMemory( sfnt_stream, sfnt, woff2.actual_sfnt_size );
sfnt_stream->memory = stream->memory;
sfnt_stream->close = stream_close;
FT_Stream_Free(
face->root.stream,
( face->root.face_flags & FT_FACE_FLAG_EXTERNAL_STREAM ) != 0 );
face->root.stream = sfnt_stream;
face->root.face_flags &= ~FT_FACE_FLAG_EXTERNAL_STREAM;
/* Set face_index to 0 or -1. */
if ( *face_instance_index >= 0 )
*face_instance_index = 0;
else
*face_instance_index = -1;
FT_TRACE2(( "woff2_open_font: SFNT synthesized.\n" ));
Exit:
FT_FREE( tables );
FT_FREE( indices );
FT_FREE( uncompressed_buf );
FT_FREE( info.x_mins );
if ( woff2.ttc_fonts )
{
WOFF2_TtcFont ttc_font = woff2.ttc_fonts;
for ( nn = 0; nn < woff2.num_fonts; nn++ )
{
FT_FREE( ttc_font->table_indices );
ttc_font++;
}
FT_FREE( woff2.ttc_fonts );
}
if ( error )
{
FT_FREE( sfnt );
if ( sfnt_stream )
{
FT_Stream_Close( sfnt_stream );
FT_FREE( sfnt_stream );
}
}
return error;
}
#undef READ_255USHORT
#undef READ_BASE128
#undef ROUND4
#undef WRITE_USHORT
#undef WRITE_ULONG
#undef WRITE_SHORT
#undef WRITE_SFNT_BUF
#undef WRITE_SFNT_BUF_AT
#undef N_CONTOUR_STREAM
#undef N_POINTS_STREAM
#undef FLAG_STREAM
#undef GLYPH_STREAM
#undef COMPOSITE_STREAM
#undef BBOX_STREAM
#undef INSTRUCTION_STREAM
#else /* !FT_CONFIG_OPTION_USE_BROTLI */
/* ANSI C doesn't like empty source files */
typedef int _sfwoff2_dummy;
#endif /* !FT_CONFIG_OPTION_USE_BROTLI */
/* END */