0.4.0.0 (2026-10-15)
====================
Breaking changes:
- New encoding API: `encodeBlpWith` and `writeBlpWith` take
`BlpEncodeOptions` (a `BlpFormat` and a mip level count) and return
`Either BlpEncodeError`. Empty images, sides above 65535, JPEG quality
outside 1..100 and files over 4 GiB are errors instead of crashes or
silent wrap-around (#31). `encodeBlpJpeg`, `encodeBlpUncompressedWithAlpha`,
`encodeBlpUncompressedWithoutAlpha` and their `writeBlp*` variants still
work as deprecated wrappers; they clamp the JPEG quality, which used to
wrap modulo 256.
- The decoder takes alpha from the `alphaBits` header field, as the format
specifies, instead of from the `extra` field. Paletted files with 1-bit and
4-bit alpha now decode, files whose `extra` field says otherwise keep their
alpha, and unknown `extra` values are no longer rejected (#25).
- Non-square textures get the full mip chain down to 1x1 instead of
stopping when the shorter side reaches one pixel, and `mipMapsUpTo` counts
levels by the larger side, capped at 16 (#26, #31).
- Mipmap colour is averaged with alpha as the weight, so transparent pixels
no longer darken the edges of sprites, and the alpha of paletted mipmaps
is averaged instead of sampled. Opaque textures encode exactly as before
(#32).
- `Codec.Picture.Blp.Internal.*`:
- `BlpStruct` keeps the raw header values in `blpAlphaBits`, `blpExtra` and
`blpHasMipmaps`; `blpCompression` is a function of `blpExt`. `BlpFlag` and
`BlpPictureType` are gone.
- Paletted content is one `BlpPaletted` constructor holding each level's
raw data.
- The parser is `parseBlp` plus `mipLevels` and `jpegFrameSize`; the
attoparsec walk over the content (`blpJpegParser`, `skipToOffset`, ...)
is gone.
- `encodeBlp` and `blpEncoder` take just the `BlpStruct`; `toBlpStruct`
takes a `BlpFormat`.
Decoding untrusted files (#30):
- Errors that JuicyPixels' JPEG decoder raises from pure code are returned
as `Left`; in a tail mipmap they end the list.
- Width and height must be between 1 and 65535. Larger values used to
overflow the size checks and leave an exception in the decoded image.
- Each JPEG level's frame size is read before decoding. A frame larger than
the level is rejected, so an 800-byte file can no longer demand gigabytes;
a smaller one is padded with transparent black.
- Mipmap slots are read by index. A missing or garbage slot ends the chain
instead of shifting the later levels, and a garbage slot that points into
the palette no longer breaks the file.
- Some corrupt JPEG streams still make JuicyPixels loop forever
(haskell-github-trust/Juicy.Pixels#230), so decoding untrusted files needs
a timeout.
Encoder fixes (#31):
- Unused mipmap slots are zero, as the format requires, and `hasMipmaps` is
0 when only one level is written.
- Only the levels that are written are encoded; asking for one level of a
2048x2048 JPEG texture used to encode all of them.
Faster (#34): JPEG decoding is 2.1–2.7x and JPEG encoding 2.2–2.8x as fast,
measured with the new benchmark suite (`bench/Main.hs`). Output is
byte-identical.
blp2any (#33):
- `-s`/`--shallow` and `-p` (now also `--flatten`) were accepted but did
nothing; they now keep conversion to the top folder and write all output
into one folder.
- A file that fails no longer aborts a batch conversion or `stats`: it is
reported on stderr and skipped, and `convert` prints a summary and exits
with status 1 if anything failed.
- An input folder given with a trailing slash no longer sends output to the
root of the file system.
- `--version` reports the package version.
Documentation: `docs/format.md` describes the BLP1 format and what the
library does with each part; the README covers usage, `blp2any`,
limitations and benchmarking; every module has haddock (#27).
0.3.0.0 (2026-10-15)
====================
Breaking changes:
- `encodeBlpUncompressedWithAlpha` always writes an alpha plane and
`encodeBlpUncompressedWithoutAlpha` never does. Both used to pick by the
input image, so the two were identical and `blp2any -b` had no effect.
- `decodeBlp` and `decodeBlpMipmaps` always return `ImageRGBA8`. JPEG BLPs
whose stream is not four-component (greyscale, YCbCr) used to come back as
`ImageY8` or `ImageRGB8`.
- Removed unused functions from `Codec.Picture.Blp.Internal.Convert`:
`toPngRepresentable` and `toBlpUncompressable`.
- `mipMapsUpTo` counts every level down to the minimum side; it was one short
and returned 0 or less for tiny images.
- Removed the `TextShow` and `Hashable` instances from
`Codec.Picture.Blp.Internal.Data`, and with them the `text-show` and
`hashable` dependencies. `blp2any` no longer depends on
`unordered-containers`.
The encoder always writes mip 0; a mipmap count of zero or less used to
produce an unreadable file, which `blp2any` did for 1x1 images.
The uncompressed encoder no longer hands out ByteStrings over image memory it
does not keep alive, and no longer relies on an orphan, endianness-dependent
`Storable PixelRGBA8` instance.
Decoder robustness for BLP1 files found in the wild:
- Accept picture type 6 (WoW JPEG variant) and picture type 0 (#5, #10).
- Tolerate palettes shorter than 256 entries (#6).
- Decode files labelled with-alpha whose mipmap 0 has no alpha plane as
without-alpha instead of crashing (#8).
- A corrupt JPEG mipmap no longer fails the whole file; the mipmap list is
cut at the first broken level (#9).
- `decodeBlpMipmaps` renders uncompressed mipmaps at their own sizes instead of
crashing; a mip 0 too short for the image is a `Left` (#13).
- Without-alpha textures decode opaque regardless of the palette's fourth
byte, so the encoder's own output no longer comes back transparent (#14).
- Decoding no longer dumps the parsed structure to stderr (#15).
- The JPEG encoder writes plain BGRA planes instead of dividing colour by
alpha, and a uniformly semi-transparent alpha plane is kept; only all-0x00
or all-0xFF planes count as unpopulated (#17).
- The JPEG encoder shares one header between mipmaps; 1x1 textures no longer
encode to a file without image data (#18).
- Skip mipmap slots that point past the end of the file or overlap an earlier
one (#7).
- Decode JPEG planes as BGRA instead of CMYK (#11).
Support GHC 9.4 – 9.14: relax upper bounds for `attoparsec`, `bytestring`,
`hashable`, `text-show`, `vector` and `filepath`. Minimum supported GHC is now 9.4.
0.2.1.0
=======
Relax upper boundary for `text-show-3.9`.
0.2.0.0
=======
Implement #1. Tool now preserves subfolder structure.
0.1.3.0
=======
Fix #2 index error.
0.1.2.0
=======
Relax upper boundary for `hashable` and `text-show`.
0.1.1.0
=======
Relax upper boundary for `JuicyPixels-3.3`.
0.1.0.1
=======
Relax upper boundary for `binary-0.9.0.0`.
0.1.0.0
=======
Initial release.