Blizzard Shaders

An open-source effort to reverse-engineer and reimplement the shaders used by Blizzard's games, then re-pack the results into the engine's own shader-bundle wire formats so they can be dropped back into the game.

Every game here runs on a shared lineage of Blizzard engine tech — the same StormLib SComp compression, the same .fx / BLS shader tooling — so the reconstruction toolchain is shared: shaders are authored once in Slang, compiled to the target bytecode, and packed back into the game's bundle format, with correctness verified against the retail blobs.

Sub-projects

Game	Status	Details
Warcraft III: Reforged	✅ Complete & verified	README-Warcraft3.md
StarCraft II / Heroes of the Storm	🚧 Reverse engineering in progress	docs/SC2_SHADERS_PLAN.md

Warcraft III: Reforged

The complete, shipped-parity half of the repo. All 19 shipped shader families — SD, SD-on-HD, HD, Crystal, water, terrain, foliage, sprite, distortion, PopcornFX particles, and the tonemap — are reimplemented in Slang and re-packed into the game's .bls bundles, DX and Metal, with optional OpenGL / Vulkan / WebGPU output for engine ports. Correctness is proven bit-identical against the retail DXBC via a custom DXBC interpreter harness. A custom_shaders module layers user-authored variants (e.g. a toon / cel-shaded HD look) on top of the reconstruction.

→ Full build instructions, family list, and the custom-shader guide live in README-Warcraft3.md.

StarCraft II / Heroes of the Storm

Active reverse-engineering work targeting the StarCraft II engine (shared with Heroes of the Storm, which uses the same .fx über-shaders, baselinecache.bin container, and StormLib SComp compression).

Unlike Warcraft III — which ships pre-compiled BLS bundles that give a fixed permutation set and an extractable retail-DXBC anchor — SC2 ships a MSER baselinecache.bin cache with neither. So the reconstruction strategy inverts, and the current focus is cache mining: recovering the exact retail permutation set and its per-permutation feature vectors, then anchoring correctness on the plaintext OpenGL3 GLSL the cache stores in the clear.

Progress so far:

• Container & compression reversed. The baselinecache.bin / MSER format and the StormLib FGK adaptive-Huffman (SComp) decompressor are decoded — see tools/storm_huffman.py (a faithful port of StormLib's huff.cpp, confirmed against the reversed Wc3 debug build) and docs/SC2_BASELINECACHE_ANALYSIS.md.
• Family taxonomy mapped. All 50 shader entry points and their b_* permutation axes are catalogued in docs/SC2_SHADER_FAMILIES.md (build 41359: 65,369 unique compiled permutations, 101,184 named retail instances).
• Cache mining largely done. The Metal-cache instance names, the Payload2 key-token codec (byte-exact port of the client's decoder), and the GL GLSL blobs are joined into per-family manifests under sc2_perms/ — 44 (family, entry) pairs, every decoded feature vector unique.
• Next up. Naming the decoded key fields → b_* axes, then scaffolding an sc2_shaders/ Slang module (mirroring wc3_shaders/) and validating the model über-shader against the retail GLSL, before packing to BLS v1.14.

→ The full plan, milestones, and verification strategy live in docs/SC2_SHADERS_PLAN.md.

Shared toolchain

The build engine is shared across sub-projects; the SC2 work reuses it directly rather than forking it.

Path	Purpose
compile_all_slang.py	The permutation sweep engine — compiles every permutation of every family to a chosen graphics API target (D3D11, Metal, GL, Vulkan, WebGPU).
build_bls.py	Packs compiled bytecode into .bls bundles. Handles the v1.8 / v1.12 / v1.14 outer containers and the DX / Metal / extra-backend inner layouts.
shader_config.py	Merges the per-project family JSONs into a single config view.
tools/	Reverse-engineering utilities, including the StormLib SComp / Huffman decompressor shared by the SC2/HotS/Wc3 engines.
docs/	Format specifications and per-game reverse-engineering plans and analyses.
re_shaders/	Per-family retail disassembly, notes, and comparison reports.

Reference documentation

Document	Covers
docs/BLS_FILE_FORMAT_SPECIFICATION.md	The BLS shader-bundle wire format (v1.8 / v1.12 / v1.14).
docs/SHADER_VERIFICATION.md	How reconstructed shaders are verified against retail bytecode.
docs/SC2_BASELINECACHE_ANALYSIS.md	The SC2 baselinecache.bin container and its SComp compression.
docs/SC2_SHADER_FAMILIES.md	The SC2 family taxonomy and per-family permutation axes.
docs/SC2_SHADERS_PLAN.md	The plan to reimplement SC2 .fx shaders as Slang → BLS v1.14.

License

Source is released under the BSD 3-Clause License — see LICENSE.

An additional LICENSE-AI.md notice clarifies that AI-generated derivative works are subject to the same attribution and license conditions as any other derivative work.

This project is an independent, fan-made reimplementation and is not affiliated with or endorsed by Blizzard Entertainment. Warcraft III, StarCraft II, and Heroes of the Storm are trademarks of Blizzard Entertainment.