Added stalagtites

world/src/index.rs

@@ -1,10 +1,11 @@
 use crate::site::Site;
 use common::store::{Id, Store};
+use noise::{NoiseFn, Seedable, SuperSimplex};
 
-#[derive(Default)]
 pub struct Index {
     pub seed: u32,
     pub time: f32,
+    pub noise: Noise,
     pub sites: Store<Site>,
 }
 
@@ -12,7 +13,21 @@ impl Index {
     pub fn new(seed: u32) -> Self {
         Self {
             seed,
-            ..Self::default()
+            time: 0.0,
+            noise: Noise::new(seed),
+            sites: Store::default(),
+        }
+    }
+}
+
+pub struct Noise {
+    pub cave_nz: SuperSimplex,
+}
+
+impl Noise {
+    fn new(seed: u32) -> Self {
+        Self {
+            cave_nz: SuperSimplex::new().set_seed(seed),
         }
     }
 }

world/src/layer/mod.rs

@@ -9,7 +9,8 @@ use common::{
     lottery::Lottery,
     assets,
 };
-use std::f32;
+use noise::NoiseFn;
+use std::{f32, ops::{Sub, Mul}};
 use vek::*;
 
 pub fn apply_paths_to<'a>(
@@ -138,6 +139,18 @@ pub fn apply_caves_to<'a>(
                     let _ = vol.set(Vec3::new(offs.x, offs.y, z), Block::empty());
                 }
 
+                // Stalagtites
+                let stalagtites = index.noise.cave_nz
+                    .get(wpos2d.map(|e| e as f64 * 0.1).into_array())
+                    .sub(0.6)
+                    .max(0.0)
+                    .mul((col_sample.alt - cave_roof as f32 - 5.0).mul(0.15).clamped(0.0, 1.0) as f64)
+                    .mul(40.0) as i32;
+
+                for z in cave_roof - stalagtites..cave_roof {
+                    let _ = vol.set(Vec3::new(offs.x, offs.y, z), Block::new(BlockKind::Normal, Rgb::broadcast(200)));
+                }
+
                 // Scatter things in caves
                 if RandomField::new(index.seed).chance(wpos2d.into(), 0.001) && cave_base < surface_z as i32 - 25 {
                     let kind = *assets::load_expect::<Lottery<BlockKind>>("common.cave_scatter")