ref: 81cf5326d59282265ccc0911050005a4b5d20a99
parent: 106bacf5022e8c7c8bdcd8407efd64fb6db182b4
author: Nikhil Ramakrishnan <ramakrishnan.nikhil@gmail.com>
date: Sat Jul 6 14:05:18 EDT 2019
[woff2] Copy un-transformed tables to sfnt stream. Copy un-transformed tables to the sfnt stream. * src/sfnt/sfwoff2.c: (WRITE_SFNT_BUF): New macro. (write_buf): New function. Extend memory of `dst' buffer and copy bytes from `src'. (compute_ULong_sum): New function. Calculate checksum of table. (reconstruct_font): Change `FT_Byte* sfnt' to `FT_Byte** sfnt_bytes'. This has been done because we reallocate memory to `sfnt' multiple times, which may change the pointer value of `sfnt'. This new pointer must be propogated back to the caller. Same reason for using a double pointer in `write_buf'. * src/sfnt/woff2tags.h (WOFF2_DEFAULT_MAX_SIZE): New macro used for overflow checking.
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,24 @@
2019-08-27 Nikhil Ramakrishnan <ramakrishnan.nikhil@gmail.com>
+ [woff2] Copy un-transformed tables to sfnt stream.
+
+ Copy un-transformed tables to the sfnt stream.
+
+ * src/sfnt/sfwoff2.c: (WRITE_SFNT_BUF): New macro.
+ (write_buf): New function. Extend memory of `dst' buffer and copy
+ bytes from `src'.
+ (compute_ULong_sum): New function. Calculate checksum of table.
+ (reconstruct_font): Change `FT_Byte* sfnt' to `FT_Byte**
+ sfnt_bytes'. This has been done because we reallocate memory to
+ `sfnt' multiple times, which may change the pointer value of `sfnt'.
+ This new pointer must be propogated back to the caller. Same reason
+ for using a double pointer in `write_buf'.
+
+ * src/sfnt/woff2tags.h (WOFF2_DEFAULT_MAX_SIZE): New macro used for
+ overflow checking.
+
+2019-08-27 Nikhil Ramakrishnan <ramakrishnan.nikhil@gmail.com>
+
[woff2] Create stream for uncompressed buffer.
Uncompressed buffer is now an `FT_Stream'.
--- a/src/sfnt/sfwoff2.c
+++ b/src/sfnt/sfwoff2.c
@@ -64,6 +64,8 @@
\
} while ( 0 )
+#define WRITE_SFNT_BUF( buf, s ) \
+ write_buf( &sfnt, &dest_offset, buf, s, memory )
static void
stream_close( FT_Stream stream )
@@ -182,6 +184,41 @@
}
+ static FT_Error
+ write_buf( FT_Byte** dst_bytes,
+ 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 if we are within limits. */
+ if( ( *offset + size ) > WOFF2_DEFAULT_MAX_SIZE )
+ return FT_THROW( Array_Too_Large );
+
+ /* DEBUG - Remove later */
+ FT_TRACE2(( "Reallocating %lu to %lu.\n", *offset, (*offset + size) ));
+ /* Reallocate `dst'. */
+ if ( FT_REALLOC( dst,
+ (FT_ULong)(*offset),
+ (FT_ULong)(*offset + size ) ) )
+ goto Exit;
+
+ /* Copy data. */
+ ft_memcpy( dst + *offset, src, size );
+
+ *offset += size;
+ /* Set pointer of `dst' to its correct value. */
+ *dst_bytes = dst;
+
+ Exit:
+ return error;
+ }
+
+
static FT_Offset
CollectionHeaderSize( FT_ULong header_version,
FT_UShort num_fonts )
@@ -216,7 +253,33 @@
return offset;
}
+ static FT_Long
+ compute_ULong_sum( FT_Byte* buf,
+ FT_ULong size )
+ {+ FT_ULong checksum = 0;
+ FT_ULong aligned_size = size & ~3;
+ FT_ULong i;
+ FT_ULong v;
+ for( i = 0; i < aligned_size; i += 4 )
+ {+ checksum += ( buf[i] << 24 ) | ( buf[i+1] << 16 ) |
+ ( buf[i+2] << 8 ) | ( 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 |= buf[i] << ( 24 - 8 * ( i & 3 ) );
+ checksum += v;
+ }
+ return checksum;
+ }
+
+
static FT_Error
woff2_uncompress( FT_Byte* dst,
FT_ULong dst_size,
@@ -293,15 +356,17 @@
FT_ULong transformed_buf_size,
WOFF2_Table* indices,
WOFF2_Header woff2,
- FT_Byte* sfnt,
+ FT_Byte** sfnt_bytes,
FT_Memory memory )
{FT_Error error = FT_Err_Ok;
FT_Stream stream = NULL;
+ FT_Byte* buf_cursor = NULL;
+ /* We are reallocating memory for `sfnt', so its pointer may change. */
+ FT_Byte* sfnt = *sfnt_bytes;
- /* We're writing only one face per call, so initial offset is fixed. */
- FT_ULong dst_offset = 12;
FT_UShort num_tables = woff2->num_tables;
+ FT_ULong dest_offset = 12 + num_tables * 16UL;
FT_ULong checksum = 0;
FT_ULong loca_checksum = 0;
@@ -333,7 +398,6 @@
}
}
- FT_UNUSED( dst_offset );
FT_UNUSED( loca_checksum );
FT_UNUSED( checksum );
@@ -351,12 +415,14 @@
WOFF2_TableRec table = *( indices[nn] );
/* DEBUG - Remove later */
- FT_TRACE2(( "Seeking to %d with table size %d.\n", table.src_offset, table.src_length ));
+ FT_TRACE2(( "Seeking to %d with table size %d.\n",
+ table.src_offset, table.src_length ));
FT_TRACE2(( "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 ) )
return FT_THROW( Invalid_Table );
@@ -370,6 +436,7 @@
return FT_THROW( Invalid_Table );
}
+ checksum = 0;
if( ( table.flags & WOFF2_FLAGS_TRANSFORM ) != WOFF2_FLAGS_TRANSFORM )
{/* Check if `head' is atleast 12 bytes. */
@@ -377,12 +444,30 @@
{if( table.src_length < 12 )
return FT_THROW( Invalid_Table );
+ buf_cursor = transformed_buf + table.src_offset + 8;
+ WRITE_ULONG( buf_cursor, 0 );
}
+ table.dst_offset = dest_offset;
+ checksum = compute_ULong_sum( transformed_buf + table.src_offset,
+ table.src_length );
+ /* DEBUG - Remove later */
+ FT_TRACE2(( "Checksum = %u\n", checksum ));
+
+ if( WRITE_SFNT_BUF( transformed_buf + table.src_offset,
+ table.src_length ) )
+ return FT_THROW( Invalid_Table );
}
+ else{+ /* DEBUG - Remove later */
+ FT_TRACE2(( "This table has xform.\n" ));
+ /* TODO reconstruct transformed font tables! */
+ }
+
}
- /* TODO reconstruct the font tables! */
+ /* Set pointer of sfnt stream to its correct value. */
+ *sfnt_bytes = sfnt;
return FT_Err_Ok;
}
@@ -793,7 +878,7 @@
/* TODO Write table entries. */
reconstruct_font( uncompressed_buf, woff2.uncompressed_size,
- indices, &woff2, sfnt, memory );
+ indices, &woff2, &sfnt, memory );
error = FT_THROW( Unimplemented_Feature );
/* DEBUG - Remove later */
@@ -821,6 +906,7 @@
#undef ROUND4
#undef WRITE_USHORT
#undef WRITE_ULONG
+#undef WRITE_SFNT_BUF
/* END */
--- a/src/sfnt/woff2tags.h
+++ b/src/sfnt/woff2tags.h
@@ -33,6 +33,9 @@
#define WOFF2_SFNT_HEADER_SIZE 12
#define WOFF2_SFNT_ENTRY_SIZE 16
+ /* Suggested max size for output. */
+#define WOFF2_DEFAULT_MAX_SIZE 30 * 1024 * 1024
+
FT_LOCAL( FT_ULong )
woff2_known_tags( FT_Byte index );