Reconstruct `glyf' table if it is transformed in the uncompressed
table stream. Also add necessary structures, macros and functions.
* include/freetype/internal/wofftypes.h (WOFF2_InfoRec,
WOFF2_SubstreamRec, WOFF2_PointRec): New structures.
(WOFF2_TableRec): s/OrigLength/dst_length/.
* src/sfnt/sfwoff2.c (READ_255USHORT, READ_BASE128): Use
`FT_SET_ERROR' to set implicit `error' variable.
(WRITE_SHORT): New macro.
(N_CONTOUR_STREAM, N_POINTS_STREAM, FLAG_STREAM, GLYPH_STREAM,
COMPOSITE_STREAM, BBOX_STREAM, INSTRUCTION_STREAM): New macros to
refer to substreams of the transformed `glyf' tables.
(Read255UShort, ReadBase128): Return errors set by `FT_READ_XXX'
macros.
(with_sign, safe_int_addition): New functions to add sign to values
based on a flag and perform safe addition respectively.
(triplet_decode): Decode variable-length (flag, xCoordinate,
yCoordinate) triplet for a simple glyph. See
https://www.w3.org/TR/WOFF2/#triplet_decoding
(store_points, compute_bbox, composteGlyph_size, reconstruct_glyf):
New functions.
(reconstruct_font): Call `reconstruct_glyf'.
* src/sfnt/sfwoff2.h: Add required constants.
* src/sfnt/woff2tags.h: Move out constants to `sfwoff2.h'.
WOFF2 compressed stream is now uncompressed if Brotli is available.
This data is stored in a separate buffer (uncompressed_buf) because
it does not contain direct table data. Certain tables have
transformations applied to them, and they must be reconstructed
before we can write those tables to the SFNT stream.
`face_index' is now being passed as a parameter to
`woff2_open_font'.
* src/sfnt/sfobjs.c (sfnt_open_font): Add parameter
`face_instance_index'.
* src/sfnt/sfwoff2.c (woff2_uncompress): New function.
(woff2_open_font): Call `woff2_uncompress'.
(compute_first_table_offset): Fix return type.
* src/sfnt/sfwoff2.h (woff2_open_font): Modify declaration.
Check for WOFF2 tag, call `woff2_open_font', and implement it to read
header according to specification.
* include/freetype/internal/fttrace.h: Add `sfwoff2.c'.
* src/sfnt/rules.mk (SFNT_DRV_SRC): Add `sfwoff2.c'.
* src/sfnt/sfnt.c: Include `sfwoff2.c'.
* src/sfnt/sfobjs.c (sfnt_open_font): Check for `wOF2' tag and call
`woff2_open_font'.
* src/sfnt/sfwoff2.c, src/sfnt/sfwoff2.h: New files.
