shadertoy-cli

Agent-friendly ShaderToy project, rendering, debugging, and live-preview CLI.

The installed binary is named shadertoy.

cargo binstall shadertoy-cli
shadertoy new demo --template multipass
cd demo
shadertoy check
shadertoy render -o target/frame.png
shadertoy render-frames --range 0:180:60 --contact-sheet target/contact.png
shadertoy render-video --frames 180 -o target/clip.mp4
shadertoy sweep --frame 120 --set foam_gain=0.8,1.0,1.2
shadertoy inspect buffer buffer-a --frame 120 --pixel 8,8 --set foam_gain=1.0
shadertoy inspect storage particle-state --frame 120 --type f32 --count 16
shadertoy profile --frame 120 --samples 30
shadertoy test
shadertoy preview --record target/session.strec
shadertoy replay target/session.strec -o target/replay.png

The CLI embeds its project templates, JSON Schema, agent documentation, preview web UI, and Camoufox import helper, so the installed executable does not need adjacent data files. Built-in topics are available through shadertoy docs for agent, project, import, manifest, passes, glsl, assets, buffers, channels, state, sweep, and preview guidance. Use shadertoy docs glsl for the generated prelude/entry-point contract and shadertoy docs assets for cubemap and volume file layouts.

Import a public ShaderToy into a fully local editable project:

shadertoy import https://www.shadertoy.com/view/lsX3W4 -o mandelbrot
cd mandelbrot
shadertoy check

Import uses a Camoufox browser session to handle ShaderToy's browser/Cloudflare path. On first use it creates a private cached Python environment, installs the pinned Camoufox adapter, and fetches its browser. Python 3.10+ is required. On Linux, the Camoufox browser also needs the usual Firefox GTK runtime (for Debian/Ubuntu, libgtk-3-0 or its distro equivalent). Supported textures, cubemaps, volumes, file-backed video inputs, and Sound passes are materialized into the local project; the original ShaderToy response is retained under .shadertoy/import-response.json. Webcam inputs remain live-preview-only.

See the repository README for project format, state/debugging workflows, and the underlying C++/Rust library architecture.

The underlying C++ renderer was originally written by Yingwei Zheng (dtcxzyw/shadertoy), whose groundwork this CLI builds on.

On Linux, GL-backed CLI operations including check, render, render-frames, render-video, render-audio, inspect buffer, inspect storage, state capture, profile, test, replay, and native preview use a surfaceless EGL context and do not need DISPLAY or WAYLAND_DISPLAY. render-frames and render-video reuse one deterministic runtime across their requested timeline. Encoded video and file-backed video channels require ffmpeg/ffprobe.

Additional development tooling

GLSL sources support project-local quoted #include directives. Configure shared include roots with [shader] include_dirs = ["shaders/lib"]; live preview tracks the include dependency graph and recompiles only affected passes, preserving feedback buffers when possible.

Projects can declare typed custom uniforms with [[uniform]]; defaults are applied everywhere, deterministic rendering/state-capture/runtime-inspection commands accept --set name=value, preview exposes matching controls, and [[test]] cases can override them independently. shadertoy sweep --set gain=0.8,1.0,1.2 renders parameter variants and a contact sheet without temporary project copies. profile reports mean, median, p95, min, and max timing statistics.

Buffer passes can opt into fixed width/height render targets for stable simulation grids, while each iChannel can independently choose filter = "nearest" | "linear" | "mipmap" and wrap = "clamp" | "repeat".

For heavier pipelines, kind = "compute" adds fixed-size OpenGL 4.3 compute dispatch, typed r32f/rg32f/rgba16f/rgba32f outputs, repeated dispatch iterations via iIteration, writable iOutput image load/store, and persistent named SSBOs shared across passes. Buffer/compute passes can also expose up to eight render targets with extra_outputs, and consumers select an attachment with output = N. inspect buffer --output-index N --raw ... reads any MRT attachment, while inspect storage can decode/dump a named SSBO. .ststate format 4 can optionally include SSBO bytes with state capture --include-storage. See shadertoy docs passes and shadertoy docs channels for the exact semantics.

For automated visual/numeric validation, add [[test]] cases to ShaderToy.toml and run shadertoy test. Visual cases compare deterministic PNGs with an RMSE tolerance and emit actual/expected/diff artifacts on failure; buffer cases can also assert no NaN/Inf values and finite-value mean ranges. Tests can also expand across frames = [...] and resolutions = [[w,h], ...], repeat each variant with assert_deterministic = true, and prove fixed GPU simulation grids are independent of output size with assert_resolution_independent = true.

ShaderToy Sound passes (kind = "sound") are compiled by check and render to deterministic stereo PCM WAV with shadertoy render-audio. File-backed video assets update at deterministic iTime and expose iChannelTime; webcam channels are available only in live preview and are intentionally rejected by headless render/replay/recording.