fastnoise2-sys

Low-level Rust FFI bindings for FastNoise2, a high-performance noise generation library with SIMD support.

Building

Native Platforms (Linux, Windows, macOS)

Native builds use CMake and require a C++17 compiler:

cargo build

WebAssembly (WASM)

WASM builds require the Emscripten SDK:

1. Install Emscripten

# Clone the emsdk repository
git clone https://github.com/emscripten-core/emsdk.git
cd emsdk

# Install and activate Emscripten 3.1.68 or later
./emsdk install 3.1.68
./emsdk activate 3.1.68

# Add Emscripten to your environment
source ./emsdk_env.sh

Note: You need to run source ./emsdk_env.sh in each new terminal session before building for WASM.

2. Build for WASM

cargo build --target wasm32-unknown-emscripten

The build script will automatically detect the Emscripten target and use Emscripten to compile FastNoise2.

Custom Emscripten Flags

You can pass custom flags to emcc via the EMCC_CFLAGS environment variable:

export EMCC_CFLAGS="-s ERROR_ON_UNDEFINED_SYMBOLS=0"
cargo build --target wasm32-unknown-emscripten

Environment Variables

Variable	Purpose	Required
`EMSDK`	Path to Emscripten SDK	Yes (WASM only)
`EMCC_CFLAGS`	Custom flags for emcc	No
`FASTNOISE2_SOURCE_DIR`	Override FastNoise2 source path	No
`FASTNOISE2_LIB_DIR`	Use precompiled library	No
`FASTNOISE2_BINDINGS_DIR`	Cache directory for bindings	No

Troubleshooting

Error: "EMSDK environment variable required for WASM builds"

You need to install and activate the Emscripten SDK (see instructions above), then source the environment:

source /path/to/emsdk/emsdk_env.sh

Slow bindgen compilation

Set FASTNOISE2_BINDINGS_DIR to cache generated bindings:

export FASTNOISE2_BINDINGS_DIR=~/.cache/fastnoise2-bindings
cargo build --target wasm32-unknown-emscripten

License

This crate provides bindings to FastNoise2, which is licensed under the MIT License.

fastnoise2-sys 0.2.0