ShaderFmt

A desktop code formatter and editor for shader source code. Paste or open a shader, format it in place, tweak the result, copy it out — all without ever leaving the editor.

Features

• Formats without changing behavior. Only whitespace, indentation, and brace placement are ever touched — never your code's logic.
• Six shader dialects, auto-detected from what you paste (or pick manually):
  • GLSL (OpenGL/Vulkan)
  • Shadertoy (GLSL with mainImage, iTime, iResolution, etc.)
  • HLSL (DirectX)
  • WGSL (WebGPU)
  • MSL (Metal Shading Language)
  • Unity ShaderLab (including embedded Cg/HLSL CGPROGRAM blocks)
• Configurable style: indentation width, tabs vs. spaces, brace style (K&R or Allman), spacing around control-flow keywords, and a visual line-length guide — with one-click presets (Default, Shadertoy, Unreal, Unity) and a live preview. Your preferences are remembered between sessions.
• Format-on-the-fly, undo/redo, drag-and-drop, open/save files.
• Non-blocking hints: a GLSL-specific check flags qualifiers that don't match your #version (e.g. attribute/varying used with #version 330, or layout(...) used before #version 140) with a gentle underline — it never stops you from formatting or editing.
• Live render preview (GLSL/Shadertoy only): a docked panel renders your fragment shader on a fullscreen quad as you type, with Shadertoy's standard iResolution/iTime/iMouse/iFrame uniforms wired up and animated continuously. Debounced independently of format-on-the-fly, so it doesn't recompile on every keystroke. Falls back to a plain message (compile error, or "not available for this language") instead of a fake or silently-wrong render for anything it can't show — HLSL/WGSL/ MSL/ShaderLab would each need their own real graphics backend (Direct3D/wgpu/Metal/Unity itself), none of which are wired up here.
• Runs entirely offline. Nothing is ever sent anywhere.

Installing

Windows builds are available from the Releases page: grab the .exe installer for a normal install (Start Menu shortcut, uninstaller included), or the .zip if you'd rather just unpack and run.

macOS and Linux builds aren't published yet — see Building from source below.

Building from source

Requirements: CMake 3.16+, a C++17 compiler.

cmake -S . -B build
cmake --build build -j
ctest --test-dir build --output-on-failure

The formatting engine (lib/) has no external dependencies and builds on its own. The desktop editor additionally needs Qt6 (Widgets + Concurrent) and QScintilla built against that same Qt — if Qt6 isn't found, the editor is skipped automatically and the engine/tests still build and run fine.

# 1. Qt6 (via aqtinstall)
python -m pip install aqtinstall
python -m aqt install-qt windows desktop 6.8.3 win64_msvc2022_64 -O C:/Qt

# 2. QScintilla, built from source against that Qt (no prebuilt package
#    exists for Qt6). From a Visual Studio developer command prompt,
#    with the Qt bin directory from step 1 first on PATH:
curl -LO <QScintilla-2.14.1 source tarball, from pypi.org/project/QScintilla>
tar xzf QScintilla-2.14.1.tar.gz
cd QScintilla-2.14.1/src
qmake CONFIG+=staticlib qscintilla.pro
nmake
nmake install

# 3. Build ShaderFmt itself, in Release (QScintilla above was built
#    Release; mixing Debug/Release causes MSVC runtime link errors)
cmake -S . -B build -DCMAKE_PREFIX_PATH=C:/Qt/6.8.3/msvc2022_64 -DCMAKE_BUILD_TYPE=Release
cmake --build build --target shaderfmt_app

On Windows, the build automatically runs windeployqt right after linking shaderfmt_app.exe, so build/app/Release/shaderfmt_app.exe (or build/app/shaderfmt_app.exe with a single-config generator) is directly runnable — its Qt DLLs are copied alongside it, no need to have Qt on PATH. If you see "missing Qt6Core.dll" or similar when running it, windeployqt wasn't found at configure time (check the CMake configure log for a warning) — make sure Qt's bin/ directory is on PATH or in CMAKE_PREFIX_PATH and reconfigure.

To produce a standalone package elsewhere (a .zip, and on Windows also an NSIS .exe installer if makensis is available):

cpack --config build/CPackConfig.cmake -B build

Known limitations

• Comments and code are preserved exactly, but multiple consecutive blank lines collapse down to a single blank line.
• The line-length setting is a visual guide only — nothing wraps long lines automatically.
• Syntax highlighting is by token category (identifier, number, string, comment, preprocessor), not by per-language keyword.
• Spacing around unary operators (-x, !x) and WGSL generics (vec3<f32>) can look slightly off in edge cases, though it's never semantically wrong.
• No Shadertoy sample ships in the test corpus due to Shadertoy's default non-commercial license — everything else is exercised against real, license-verified open-source shaders (see tests/corpus/licensed/SOURCES.md).

Contributing

See CONTRIBUTING.md for how to build, test, and add a new language or style option. Please also read our CODE_OF_CONDUCT.md.

License

GPL v3 — see LICENSE.

Copyright (c) 2026 Patrick JAILLET.