This is a pure Rust take on the classic Warcraft III BLP texture format.
No C glue, no old-school wrappers — just clean Rust that works everywhere: Windows, macOS, Linux.

It has a tiny UI made with egui — drop in a file, and boom, you can view it.
Under the hood there's a simple Rust library, perfect when you just need BLP decoding inside your own tools.

Oh, and it's part of the WarRaft toolkit — you’ll also find it used together with JASS-Tree-sitter-Rust,
which brings syntax support, analyzers, and more tooling for Warcraft III modding.

Wanna know how BLP works? Dive into the spec:
👉 BLP Specification

Command Line Interface

The blp tool can be built in two configurations:

• CLI-only (--features "cli")
• UI+CLI (--features "cli ui") – the CLI plus a native GUI viewer

The UI feature always requires CLI, so ui cannot be enabled alone.

Usage

blp [PATH]
blp <COMMAND>

• In CLI-only builds, [PATH] performs a sanity probe: it checks whether the file is a valid BLP.

  • Success → exit code 0
  • Failure → exit code 3

• In UI+CLI builds, [PATH] launches the native GUI viewer with that file (useful for “Open With…” integration).

If a <COMMAND> is provided, it always takes precedence over [PATH].

Commands

to-blp

Convert an image into BLP format.

blp to-blp <INPUT> [OUTPUT] [OPTIONS]

• <INPUT> – input file, usually a PNG
• [OUTPUT] – optional output path. If not specified, the extension will be replaced with .blp

Options:

• --mips <MASK...>
  Explicit mipmap mask as a sequence of 0/1 values (length 1–16).

  By default all mip levels are enabled.

  • 0 disables a mip level.
  • 1 keeps a mip level enabled (mainly serving to position zeros).

  Example: --mips 1 0 1 1 → all levels stay enabled except the second one, which is disabled.

• --mips-limit <N>
  Limit the number of generated mip levels (1–16).
  All levels after N are forced to false, overriding --mips if both are given.

• -q, --quality <Q>
  JPEG quality (1–100).
  Default: 100.

to-png

Convert a BLP texture into PNG format.

blp to-png <INPUT> [OUTPUT]

• <INPUT> – input file, must be BLP
• [OUTPUT] – optional output path. If not specified, the extension will be replaced with .png

Examples

Check if a BLP file is valid (CLI-only):

blp MyTexture.blp
echo $?   # → 0 if valid, 3 if invalid

Convert PNG to BLP with a custom mip mask:

blp to-blp input.png --mips 1 0 1 1 -q 85
# disables only the second mip level, all others remain enabled

blp to-blp input.png --mips-limit 4
# keeps only mip levels: 1 (base), 2, 3, 4
# disables levels:        5–16 (if they would exist)
# equivalent to:          --mips 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0

Convert BLP to PNG:

blp to-png input.blp output.png

Open BLP in GUI (UI+CLI build):

blp MyTexture.blp

Localization

All localization files are stored in assets/locales.
You are welcome to contribute a translation in your own language using whatever workflow is most convenient for you, and I will include it in the program.

It is not required to translate every key: any missing strings will automatically fall back to the default English ( en) localization. This means you can start small and expand the translation over time without breaking anything.