# fastnoise2

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fastnoise2 provides an easy-to-use and mostly safe interface for the [FastNoise2](https://github.com/Auburn/FastNoise2) C++ library, which provides modular node graph-based noise generation using SIMD.

![NoiseTool Node Tree](https://raw.githubusercontent.com/Lemonzyy/fastnoise2-rs/main/fastnoise2-rs/examples/noisetool.png)

This crate acts as a wrapper around [fastnoise2-sys](https://crates.io/crates/fastnoise2-sys), the unsafe bindings for FastNoise2.

## Examples

Here is an example of a encoded node tree, exported by FastNoise2's NoiseTool.

```rust
use fastnoise2::SafeNode;

let (x_size, y_size) = (1000, 1000);
let encoded_node_tree = "EQACAAAAAAAgQBAAAAAAQBkAEwDD9Sg/DQAEAAAAAAAgQAkAAGZmJj8AAAAAPwEEAAAAAAAAAEBAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAM3MTD4AMzMzPwAAAAA/";
let node = SafeNode::from_encoded_node_tree(encoded_node_tree).unwrap();

// Allocate a buffer of enough size to hold all output data.
let mut noise_out = vec![0.0; (x_size * y_size) as usize];

let min_max = node.gen_uniform_grid_2d(
    &mut noise_out,
    -x_size / 2, // x offset
    -y_size / 2, // y offset
    x_size,
    y_size,
    0.01, // frequency
    1337, // seed
);

// use `noise_out`!
```

You can also manually code a node tree using FastNoise2's metadata system, either with [`Node`](https://docs.rs/fastnoise2/latest/fastnoise2/struct.Node.html), or by combining generators, see [`SafeNode`](https://docs.rs/fastnoise2/latest/fastnoise2/struct.SafeNode.html).

Take a look at [examples](https://github.com/Lemonzyy/fastnoise2-rs/tree/main/fastnoise2-rs/examples) to find out more.

## Setup

fastnoise2-sys, the underlying bindings for fastnoise2, uses a build script that follows a specific order of preference for compiling and/or linking the FastNoise2 library:

1. Building from source, if the `build-from-source` feature is enabled.
2. If the `FASTNOISE2_LIB_DIR` environment variable is set to `/path/to/lib/`, that path will be searched for static `FastNoise` library.
3. If not set, it falls back to building from source.

## Building from Source

To build FastNoise2 from source using fastnoise2-sys, ensure you have:

- [CMake](https://cmake.org/)
- a C++17 compiler

## Notes

- If you prefer not to build from source, precompiled binaries are available for download from the [FastNoise2 Releases](https://github.com/Auburn/FastNoise2/releases).
- The `FASTNOISE2_SOURCE_DIR` environment variable is generally not needed as fastnoise2-sys includes the FastNoise2 source code as a Git submodule. If you need to use a different source directory, set `FASTNOISE2_SOURCE_DIR` to point to the root of the FastNoise2 source code.