fastvoxel/src/editor/world_generator.rs

use godot::{
    classes::{FastNoiseLite, Resource},
    obj::{Base, Gd},
    prelude::{Export, GodotClass, GodotConvert, Var},
};

use crate::runtime::types::IntoRuntime;
use fastnoise_lite::FastNoiseLite as RustNoise;

#[derive(GodotConvert, Var, Export, Debug, Clone, Copy, PartialEq)]
#[godot(via = i64)]
pub enum WorldGeneratorType {
    Noise2D,
    Noise3D,
    Graph,
    Flat,
}

impl Default for WorldGeneratorType {
    fn default() -> Self {
        WorldGeneratorType::Noise2D
    }
}

#[derive(GodotClass, Debug)]
#[class(init, base=Resource)]
pub struct WorldGeneratorResource {
    #[base]
    base: Base<Resource>,

    #[export]
    pub noise2d: Option<Gd<FastNoiseLite>>,
}
impl WorldGeneratorResource {
    fn convert_noise_type(
        ty: godot::classes::fast_noise_lite::NoiseType,
    ) -> fastnoise_lite::NoiseType {
        use fastnoise_lite::NoiseType as R;
        use godot::classes::fast_noise_lite::NoiseType as G;

        match ty {
            G::SIMPLEX => R::OpenSimplex2,
            G::SIMPLEX_SMOOTH => R::OpenSimplex2S,
            G::PERLIN => R::Perlin,
            G::VALUE => R::Value,
            G::VALUE_CUBIC => R::ValueCubic,
            G::CELLULAR => R::Cellular,
            _ => R::OpenSimplex2S, // reasonable default
        }
    }

    fn convert_fractal_type(
        ft: godot::classes::fast_noise_lite::FractalType,
        dft: godot::classes::fast_noise_lite::DomainWarpFractalType,
    ) -> fastnoise_lite::FractalType {
        use fastnoise_lite::FractalType as R;
        use godot::classes::fast_noise_lite::DomainWarpFractalType as D;
        use godot::classes::fast_noise_lite::FractalType as G;

        // Priority: domain-warp fractals first
        let domain_fractal = match dft {
            D::PROGRESSIVE => Some(R::DomainWarpProgressive),
            D::INDEPENDENT => Some(R::DomainWarpIndependent),
            D::NONE => None,
            _ => None,
        };

        if let Some(df) = domain_fractal {
            return df;
        }

        // Then normal fractals
        match ft {
            G::NONE => R::None,
            G::FBM => R::FBm,
            G::RIDGED => R::Ridged,
            G::PING_PONG => R::PingPong,
            _ => R::None,
        }
    }
    fn convert_cellular_distance_function(
        fnc: godot::classes::fast_noise_lite::CellularDistanceFunction,
    ) -> fastnoise_lite::CellularDistanceFunction {
        use fastnoise_lite::CellularDistanceFunction as R;
        use godot::classes::fast_noise_lite::CellularDistanceFunction as G;

        match fnc {
            G::EUCLIDEAN => R::Euclidean,
            G::EUCLIDEAN_SQUARED => R::EuclideanSq,
            G::MANHATTAN => R::Manhattan,
            G::HYBRID => R::Hybrid,
            _ => R::Euclidean,
        }
    }
    fn convert_cellular_return_type(
        ret: godot::classes::fast_noise_lite::CellularReturnType,
    ) -> fastnoise_lite::CellularReturnType {
        use fastnoise_lite::CellularReturnType as R;
        use godot::classes::fast_noise_lite::CellularReturnType as G;

        match ret {
            G::CELL_VALUE => R::CellValue,
            G::DISTANCE => R::Distance,
            G::DISTANCE2 => R::Distance2,
            G::DISTANCE2_ADD => R::Distance2Add,
            G::DISTANCE2_SUB => R::Distance2Sub,
            G::DISTANCE2_MUL => R::Distance2Mul,
            G::DISTANCE2_DIV => R::Distance2Div,
            _ => R::CellValue,
        }
    }
    fn convert_domain_warp_type(
        warp: godot::classes::fast_noise_lite::DomainWarpType,
    ) -> fastnoise_lite::DomainWarpType {
        use fastnoise_lite::DomainWarpType as R;
        use godot::classes::fast_noise_lite::DomainWarpType as G;

        match warp {
            G::SIMPLEX => R::OpenSimplex2,
            G::SIMPLEX_REDUCED => R::OpenSimplex2Reduced,
            G::BASIC_GRID => R::BasicGrid,
            _ => R::OpenSimplex2,
        }
    }
}

impl IntoRuntime<RustNoise> for WorldGeneratorResource {
    fn into_runtime(&self) -> RustNoise {
        match &self.noise2d {
            Some(noise) => {
                let mut rn = RustNoise::new();
                rn.set_seed(Some(noise.get_seed()));
                rn.set_frequency(Some(noise.get_frequency()));
                rn.set_noise_type(Some(Self::convert_noise_type(noise.get_noise_type())));
                rn.set_fractal_type(Some(Self::convert_fractal_type(
                    noise.get_fractal_type(),
                    noise.get_domain_warp_fractal_type(),
                )));
                rn.set_cellular_distance_function(Some(Self::convert_cellular_distance_function(
                    noise.get_cellular_distance_function(),
                )));
                rn.set_cellular_return_type(Some(Self::convert_cellular_return_type(
                    noise.get_cellular_return_type(),
                )));
                rn.set_domain_warp_type(Some(Self::convert_domain_warp_type(
                    noise.get_domain_warp_type(),
                )));

                return rn;
            }
            None => return RustNoise::new(),
        }
    }
}