Snavig performs a few operations on existing Blorb files. First and foremost it was developed as a way to add BPal chunks (see Blorb.md) to Blorb files so that the adaptive palettes of Zork Zero and Arthur can be used with Glk-based interpreters. Such Blorb files are backward compatible: they contain all information in the original Blorb plus the BPal chunk.
In addition, Snavig allows you to bundle a story file into an existing Blorb. This is not particularly useful for new authors, but for older games, such as some of Infocom's later titles, you can create a Blorb file that is self-contained.
On top of this, Snavig can losslessly recompress existing PNG images in the Blorb file to reduce their size, using oxipng. You do not need to install oxipng in order to use it, as Snavig is built with the oxipng crate. Generated BPal images are always compressed, so this applies only to the existing images, if any.
Snavig is not currently intended to be a general-purpose Blorb tool. Rather, it is meant to augment/update existing Blorb files in specific ways.
Requirements:
- Rust (1.77.0 or newer)
- A C++20 compiler
- Qt (5 or 6)
- A Unix-like environment, including MinGW
Snavig will probably also build fine in non-Unix environments, if build.rs is
modified to point to a Qt installation, but this is untested.
To build:
cargo build --release
Snavig always builds a new Blorb: it will not modify the input Blorb, unless you also specify that Blorb file as the output Blorb.
To run Snavig:
snavig [OPTIONS] <BLORB>
Options are:
a,--add-bpal: Add a BPal entrys,--story <STORY>: Add the specified storyc,--compress-images: Losslessly compress existing PNG imageso,--outfile <OUTFILE>: The Blorb file to create [default: out.blb]
Snavig will detect a lot of inconsistencies in the Blorb file, either aborting if the issue is egregious enough, or warning otherwise. Warnings are indicative of a real problem, though, even if a new Blorb file is generated, so they really ought to be heeded.
If no flags or options are provided, Snavig will produce a functionally equivalent Blorb file to the input, although there is no guarantee that it will be laid out in the same way.