Introduction

crustywad is a safe, documented Rust library for reading Doom WAD files. A WAD (“Where’s All the Data?”) is the container format that id Software’s Doom engine uses to store maps, graphics, audio, and other game assets.

What crustywad provides

• Parse WAD headers and lump directories from bytes or files.
• Look up lumps by index or name and access their raw bytes.
• Decode typed map-record lumps (Thing, Linedef, Sidedef, Vertex, Seg, Subsector, Node, Sector).
• Choose between strict parsing (fail fast on bad data) and lenient parsing (best-effort recovery with collected warnings).
• Optional memory-mapped loading for large WADs via the mmap feature flag.
• A small cwad CLI binary for dogfooding and quick inspection.

When to use it

Use crustywad when you need to:

• Extract lump data from IWAD or PWAD files for further processing.
• Build Doom map editors, converters, or analysis tools in Rust.
• Inspect WAD structure programmatically without a full game engine.

WAD format overview

Every WAD starts with a 12-byte header:

The lump directory follows the lump data. Each directory entry is 16 bytes:

See the Doom Wiki for the full unofficial spec.

Next steps

Start with Getting Started to add crustywad to your project and parse your first WAD file.