CHANGELOG.md

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

Unreleased

Changed

Compression

• The single-color texture downsizing optimization introduced in v0.4.0 is now disabled by default until the necessary features to better automatically determine its default value are implemented, as it caused issues with e.g. more common than expected single-color font textures.
• Updated OxiPNG, bringing image compression improvements at the cost of slightly slower execution times.

Distribution

• The official binaries have been slimmed down by not including code to show stack backtraces on panic, which never worked because such binaries don't contain the necessary debug symbol data.
• SLSA v1.0 attestations conforming to at least the level 2 of the build track are now generated for the official PackSquash binary artifacts.
  • These attestations allow security-conscious users to assert that they were generated on GitHub Actions runners with a well-defined build process, and that they have not been tampered with since they were generated.
  • The gh attestation verify and slsa-verifier tools can be used to verify these attestations with the generated provenance data.
  • The PackSquash Docker images include SLSA v0.2 attestations, generated by Docker BuildKit.
  • Due to the numerous technical advantages of SLSA attestations, in addition to their decentralized and free nature, the PackSquash project will most likely not pursue signing binaries with code signing certificates.

Performance

• The statically-linked PackSquash CLI Linux binaries now use the mimalloc memory allocator, instead of the default musl C library allocator.
  • This brings the performance of such binaries roughly in line with those packaged for Debian, which dynamically link against glibc. Previously, slowdowns of 5x or more could be expected, depending on the number of threads used.
  • Because they use statically-linked binaries, the PackSquash GitHub Action and Docker container also saw performance improvements. (Thanks @xMikux for reporting the performance differences!)
• Updated libspng to v0.7.4, bringing decoding speed and stability improvements for ARM CPUs that support NEON extensions.

Protection

• PackSquash now adds an extra layer of protection when size_increasing_zip_obfuscation is enabled on a small subset of pack files, as far as it safe to do so due to the inner workings of Minecraft. (Thanks to a Discord user for bringing this idea to my attention)
  • Select textures may optionally be more protected by changing the new may_be_atlas_texture PNG-specific option, but it is advised that you only do this if you have detailed knowledge of how the game processes textures, as otherwise the game may not load the pack correctly.

Fixed

• Packs generated with the zip_spec_conformance_level option set to disregard now reliably work on Minecraft clients running Java 22 or newer. (Thanks @mrkinau and @mihannnik for reporting the issue!)
• Shaders that depend on #moj_imported or parent-defined preprocessor variables to be syntactically correct or expand to the intended source code will no longer cause PackSquash to fail or change their semantics.
  • Since PackSquash still can't resolve #moj_import directives, this fix came at the cost of falling back to not doing any source transformations (minification, transformation) when this directive is used. Note that PackSquash will never be able to resolve these directives in the general case, because shaders can import shaders from other packs, including the default game pack, which PackSquash doesn't have access to.
  • If PackSquash cannot parse a shader, the parsing error is now considered tentative, causing a fallback to no source transformation, if the shader contains a #moj_import directive, as it cannot be ruled out that the shader source would be valid if the #moj_import is expanded.
  • In the future, we look forward to improve PackSquash #moj_import expansion capabilities. At least, we should be able to better handle the common case of imports of other shaders from the same pack.
• Include shaders now do not need to be parsable as translation units, statements or expressions. Failure to parse them as such will result in a tentative syntax error to be shown, but such an error will not be fatal and PackSquash will fall back to no source transformation.
• Include shaders consisting of a list of statements no longer have only their first instruction transformed when minifying or prettifying, which broke the semantics of the shader code.
• The UTF-8 BOM is no longer automatically stripped from properties files, as they should not be encoded in UTF-8 to begin with, and carrying on processing with mismatched encodings may cause mojibake.
• Processing input PNG files with colors in palette format should no longer sometimes cause ARM binaries to crash on CPUs that support NEON extensions. (Thanks @lucian929 for reporting the issue!)

User experience

• Some options file deserialization error messages have been shortened and made aware of the context in which they appear to suggest likely helpful corrective actions.

Removed

Internal

• Dropped build-time dependencies on time and git2 in favor of gathering version metadata during CI workflows, and falling back to Cargo-defined metadata for local builds.

0.4.0 - 2023-06-25

Added

Compression

• Added a single-color texture downsizing optimization to make textures composed of pixels of a single color as small as possible while maintaining their maximum mipmap level. (Thanks to @alumina6767 for bringing this idea to my attention!)
  • A new downsize_if_single_color file-specific option has been added to control whether this optimization is applied or not.
  • Downsizing single-color textures can have negative side effects if such textures are used with custom shaders or custom fonts. We are aware of such limitations and look forward to making PackSquash handle such cases better in the future, but feel free to let us know if you are affected by them: it can be useful to assess the impact of these limitations and discover new ones we were not aware of.
• The macOS resource fork ZIP folder (i.e., the __MACOSX folder) has been added to the set of files and folders ignored by PackSquash when ignore_system_and_hidden_files is set to true (the default value).

Distribution

• macOS binaries are now universal, containing native code for both Intel and Apple Sillicon based devices. (#41)
  • As a result, newer macOS devices with Apple Sillicon (e.g., ARM) CPUs should run PackSquash faster.
  • The performance on Intel-based devices should not be affected by this change, as the universal binaries still contain optimized x86 code.
• Published PackSquash Docker images at the GitHub Container Registry. (#111, thanks @realkarmakun for your PR!)

Protection

• Audio files can now be protected to make them harder to play outside of Minecraft via the new file-specific ogg_obfuscation option. This protection is independent of the already available ZIP layer protection, so it can be used alongside it or not, and can be applied to a subset of pack files.
  • This protection will not work for resource packs targeting Minecraft 1.13.2 or older. By default, PackSquash will force it to be disabled for such versions via the new ogg_obfuscation_incompatibility quirk.

Documentation

• Included a contributors section in the project readme, following the All Contributors specification.
• Created a changelog file.
• Added a repository pull request template.
• Added a GitHub Sponsors button to the repository.

Internal

• Configured Renovate for automated dependency updates.
• Added GitHub Codespaces configuration files to allow interested parties to quickly spin up an environment suitable for PackSquash development.

Changed

Compression

• Reworked the audio file processing code to be much faster and more effective. This is a major change that included the following smaller changes:
  • Removed the dependency on GStreamer in favor of combining several specialized libraries to accomplish the necessary audio processing tasks. This greatly samplifies PackSquash distribution and installation, removes points of failure related to the availability of GStreamer components, and makes the audio processing code more efficient. It also enabled the use of the audio processing software mentioned below.
  • Integrated OptiVorbis, a novel solution for lossless optimization and validation of the generated Ogg Vorbis files.
  • Migrated to vorbis_rs, a novel set of bindings for the best-in-breed encoder available, based on the reference Vorbis encoder implementation and the aoTuV and Lancer patchsets.
  • The default encoder bitrate management parameter selection has been optimized for much better performance and space efficiency without compromising audio quality.
  • Empty audio files (i.e., containing only complete silence) are now replaced with a minimal Ogg Vorbis file with no audio data, which significantly minimizes their size with no adverse effects for the vast majority of purposes. This optimization can be disabled if needed via the new empty_audio_optimization option.
  • The default encoder bitrate management parameters and sampling frequency are now different for mono and stereo sounds. The rationale for this change is that mono sounds tend to be shorter and mixed with other world sounds, so a drop in quality is less noticeable in them than in persistent, music-like stereo sounds.
  • PackSquash now falls back to outputting the input audio file if resampling did not help to reduce the file size, as long as channel mixing or pitch shifting are not requested. This input audio file will be optimized (and protected if requested) if the two_pass_vorbis_optimization_and_validation option is enabled (its default value).
• Revised shader processing code to partially fix long-standing preprocessor directive support issues. (Related issue: #187)
  • Switched to a new GLSL preprocessor and parser, which is much faster (its author claims about 10x faster) and allows to accept files containing preprocessor directives outside of external declaration position by expanding them before parsing.
  • minify_shader has been superseded by a new shader_source_transformation_strategy option, which now also allows prettifying shader source code.
  • Include shaders (i.e., shaders with a .glsl extension) can now be standalone statements and expressions.
  • Properly optimizing shaders in the context of Minecraft is an interesting and complex problem that we are working on. Even with this partial fix, you may find that some shaders still do not work as-is with PackSquash. For more information on the known shortcomings and current state of affairs, please read this GitHub issue comment.
• Some internal PNG compression settings have been tweaked for better performance and compression on average. In addition, PackSquash now uses the cutting-edge oxipng raw pixel API, which allows PackSquash to avoid encoding intermediate textures.

Fixed

• PackSquash no longer fails to process some audio files when using the default options. This is a consequence of the new default encoder bitrate management parameter selection.
• Audio files with more than two audio channels are no longer accepted, as they don't work with Minecraft.
• Fixed "write zero" I/O errors happening for every pack file when the spooling buffer size is set to zero. (Thanks to darkchroma for reporting this issue on Discord)
• PackSquash now accepts legacy font .bin files anywhere in a resource pack, like Minecraft does.
• Fixed D-Bus machine ID fallback lookups not working as intended on Linux platforms.

Distribution

• AppImages have been dropped in favor of statically-linked binaries as a distribution method for Linux platforms. Due to the removal of the dependency on GStreamer, AppImages are no longer considered a better overall means of distro-agnostic distribution. We don't expect the PackSquash CLI to depend on external libraries and thus switch back to AppImages anytime soon, but the future GUI may benefit from them.

User experience

• The options file deserialization error messages have been made more verbose so that they are more useful for troubleshooting syntax errors.
• PNG files with unnecessary trailing bytes at the end are no longer rejected; instead, such bytes are now silently discarded. These files do not follow the PNG specification and may cause interoperability issues, but experience has shown that popular closed-source programs (e.g., some versions of Photoshop) generate these files, and users can have a cumbersome time identifying and fixing them.
  • To achieve a better balance between problem linting capabilities and usability, future versions of PackSquash will display a non-fatal warning for the troublesome files, so that pack authors can improve the technical quality of their pack if they want to.

Documentation

• The PackSquash logo has been redesigned to give it a more modern, cleaner look. (Thanks to @MiguelDreamer for your work on this!)
• The repository README and other pieces of documentation have been updated and proofread.
  • This included updating the Discord username of the main PackSquash author, since Discord is phasing out username discriminants.
• Revamped the repository issue templates.

Internal

• Slightly optimized the space efficiency of the repeated entry lookup in legacy language files by using radix trees instead of hashmaps.
• Renamed the packsquash-cli package to packsquash_cli to better align with documented Rust crate naming conventions.
• Lots of third-party dependency updates, including prominent libraries such as imagequant, oxipng and zopfli. In particular, several oxipng updates brought significant performance and compression improvements.
  • Some dependency changes addressed minor public security advisories.
• Replaced some unmaintained CI step actions with faster, more up-to-date equivalents.
• The official PackSquash web presence has been moved to the aylas.org domain, under the easy to remember subdomain packsquash.aylas.org.
  • We were able to afford this domain, for which we pay 10.1 €/year, thanks to our financial contributors.

Options

• The following options were removed from options files:
  • open_files_limit
  • minimum_bitrate (superseded by target_bitrate_control_metric)
  • maximum_bitrate (superseded by target_bitrate_control_metric)
  • minify_shader (superseded by shader_source_transformation_strategy)
• The following options were added to options files:
  • two_pass_vorbis_optimization_and_validation
  • empty_audio_optimization
  • bitrate_control_mode
  • target_bitrate_control_metric
  • ogg_obfuscation
  • downsize_if_single_color
  • shader_source_transformation_strategy
  • is_top_level_shader
• The ogg_obfuscation_incompatibility quirk has been added to the set of quirks accepted by the work_around_minecraft_quirks option.

Removed

Performance

• The open_files_limit option has been removed because it was hard to use properly. PackSquash will instead automatically try to increase the open files limit when needed, and fall back to using fewer threads if the maximum attainable limit would not support the desired level of concurrency.

Internal

• Dropped build-time dependency on vergen in favor of directly gathering version metadata from Git during build scripts.
• Dropped the dependency on atty in favor of new Rust standard library methods.
• Removed pretty panic printing logic. With GStreamer out of the equation, panics should be much less likely to happen, so the significant binary size taken by this logic was no longer warranted.