Added rivers, improved mountains

Former-commit-id: c1b76c54d2aa8f0616c26b0724fe34c0d80ac4fd

world/src/lib.rs

@@ -1,7 +1,7 @@
 mod sim;
 
 use std::{
-    ops::{Add, Neg},
+    ops::{Add, Mul, Neg},
     time::Duration,
 };
 use noise::{NoiseFn, Perlin, Seedable};
@@ -54,12 +54,22 @@ impl World {
                 let wpos2d = Vec2::new(x, y) + Vec3::from(chunk_pos) * TerrainChunkSize::SIZE.map(|e| e as i32);
                 let wposf2d = wpos2d.map(|e| e as f64);
 
+                let max_z = self.sim
+                    .get_interpolated(wpos2d, |chunk| chunk.get_max_z())
+                    .unwrap_or(0.0) as i32;
+
                 let chaos = self.sim
                     .get_interpolated(wpos2d, |chunk| chunk.chaos)
                     .unwrap_or(0.0);
 
-                let ridge_freq = 1.0 / 128.0;
+                let damp = self.sim
-                let ridge_ampl = 96.0;
+                    .get_interpolated(wpos2d, |chunk| chunk.damp)
+                    .unwrap_or(0.0)
+                    .abs().neg().add(1.0)
+                    .mul(1.0 - chaos);
+
+                let ridge_freq = 1.0 / 125.0;
+                let ridge_ampl = 125.0;
 
                 let ridge = ridge_nz
                     .get((wposf2d * ridge_freq).into_array()).abs().neg().add(1.0) as f32 * ridge_ampl * chaos.powf(8.0);
@@ -67,19 +77,20 @@ impl World {
                 let height_z = self.sim
                     .get_interpolated(wpos2d, |chunk| chunk.alt)
                     .unwrap_or(0.0)
-                    + ridge;
+                    + ridge
+                    - damp.powf(20.0) * 32.0;
 
-                for z in base_z..base_z + 256 {
+                for z in base_z..max_z {
                     let lpos = Vec3::new(x, y, z);
                     let wpos = lpos
                         + Vec3::from(chunk_pos) * TerrainChunkSize::SIZE.map(|e| e as i32);
                     let wposf = wpos.map(|e| e as f64);
 
-                    let warp_freq = 1.0 / 48.0;
+                    let warp_freq = 1.0 / 40.0;
-                    let warp_ampl = 24.0;
+                    let warp_ampl = 45.0;
 
                     let height = height_z
-                        + warp_nz.get((wposf * warp_freq).into_array()) as f32 * warp_ampl * (chaos + 0.05);
+                        + warp_nz.get((wposf * warp_freq).into_array()) as f32 * warp_ampl * (chaos + 0.05).min(0.85);
 
                     let temp =
                         (temp_nz.get(Vec2::from(wposf * (1.0 / 64.0)).into_array()) as f32 + 1.0) * 0.5;

world/src/sim.rs

@@ -1,8 +1,8 @@
 use std::{
-    ops::{Add, Mul, Div},
+    ops::{Add, Mul, Div, Neg},
     f32,
 };
-use noise::{NoiseFn, OpenSimplex, Seedable};
+use noise::{NoiseFn, SuperSimplex, OpenSimplex, Seedable};
 use vek::*;
 use common::{
     terrain::TerrainChunkSize,
@@ -19,10 +19,14 @@ pub struct WorldSim {
 impl WorldSim {
     pub fn generate(seed: u32) -> Self {
         let mut gen_ctx = GenCtx {
-            alt_nz: OpenSimplex::new()
+            base_nz: OpenSimplex::new()
                 .set_seed(seed + 0),
-            chaos_nz: OpenSimplex::new()
+            damp_nz: SuperSimplex::new()
                 .set_seed(seed + 1),
+            chaos_nz: SuperSimplex::new()
+                .set_seed(seed + 2),
+            alt_nz: OpenSimplex::new()
+                .set_seed(seed + 3),
         };
 
         let mut chunks = Vec::new();
@@ -60,22 +64,26 @@ impl WorldSim {
                 .fold(None, |a: Option<f32>, x| a.map(|a| a.min(x)).or(Some(x))))
     }
 
-    pub fn get_interpolated<F: FnMut(&SimChunk) -> f32>(&self, pos: Vec2<i32>, mut f: F) -> Option<f32> {
+    pub fn get_interpolated<T, F>(&self, pos: Vec2<i32>, mut f: F) -> Option<T>
+        where
+            T: Copy + Default + Add<Output=T> + Mul<f32, Output=T>,
+            F: FnMut(&SimChunk) -> T,
+    {
         let pos = pos.map2(TerrainChunkSize::SIZE.into(), |e, sz: u32| e as f64 / sz as f64);
 
-        fn cubic(a: f32, b: f32, c: f32, d: f32, x: f32) -> f32 {
+        let cubic = |a: T, b: T, c: T, d: T, x: f32| -> T {
             let x2 = x * x;
 
             // Catmull-Rom splines
-            let co0 = -0.5 * a + 1.5 * b - 1.5 * c + 0.5 * d;
+            let co0 = a * -0.5 + b * 1.5 + c * -1.5 + d * 0.5;
-            let co1 = a - 2.5 * b + 2.0 * c - 0.5 * d;
+            let co1 = a + b * -2.5 + c * 2.0 + d * -0.5;
-            let co2 = -0.5 * a + 0.5 * c;
+            let co2 = a * -0.5 + c * 0.5;
             let co3 = b;
 
             co0 * x2 * x + co1 * x2 + co2 * x + co3
-        }
+        };
 
-        let mut y = [0.0; 4];
+        let mut y = [T::default(); 4];
 
         for (y_idx, j) in (-1..3).enumerate() {
             let x0 = f(self.get(pos.map2(Vec2::new(-1, j), |e, q| (e.max(0.0) as i32 + q) as u32))?);
@@ -98,11 +106,16 @@ impl WorldSim {
 }
 
 struct GenCtx {
-    chaos_nz: OpenSimplex,
+    base_nz: OpenSimplex,
+    damp_nz: SuperSimplex,
+    chaos_nz: SuperSimplex,
     alt_nz: OpenSimplex,
 }
 
+const Z_TOLERANCE: f32 = 32.0;
+
 pub struct SimChunk {
+    pub damp: f32,
     pub chaos: f32,
     pub alt: f32,
 }
@@ -111,16 +124,31 @@ impl SimChunk {
     fn generate(pos: Vec2<u32>, gen_ctx: &mut GenCtx) -> Self {
         let wposf = (pos * Vec2::from(TerrainChunkSize::SIZE)).map(|e| e as f64);
 
+        let base = (gen_ctx.base_nz.get((wposf.div(6000.0)).into_array()) as f32)
+            .add(1.0).mul(0.5)
+            .mul(100.0)
+            .add(32.0);
+
+        let damp = (0.0
+            + gen_ctx.damp_nz.get((wposf.div(2000.0)).into_array())
+            + gen_ctx.damp_nz.get((wposf.div(250.0)).into_array()) * 0.25
+            ) as f32;
+
         let chaos = (gen_ctx.chaos_nz
-            .get((wposf.div(400.0)).into_array()) as f32)
+            .get((wposf.div(1000.0)).into_array()) as f32)
-            .max(0.0)
+            .add(1.0).mul(0.5)
+            .mul(damp.max(0.0))
             .add(0.15)
-            .powf(2.0);
+            .powf(2.0)
+            .min(1.0);
 
         Self {
+            damp,
             chaos,
-            alt: (gen_ctx.alt_nz
+            alt: base + ((0.0
-                .get((wposf.div(125.0)).into_array()) as f32)
+                + gen_ctx.alt_nz.get((wposf.div(650.0)).into_array()) * 0.7
+                + gen_ctx.alt_nz.get((wposf.div(100.0)).into_array()) * 0.3
+                ) as f32)
                 .add(1.0).mul(0.5)
                 .mul(750.0)
                 .mul(chaos.max(0.05)),
@@ -128,8 +156,10 @@ impl SimChunk {
     }
 
     pub fn get_base_z(&self) -> f32 {
-        const BASE_Z_TOLERANCE: f32 = 32.0;
+        self.alt - Z_TOLERANCE
+    }
 
-        self.alt - BASE_Z_TOLERANCE
+    pub fn get_max_z(&self) -> f32 {
+        self.alt + Z_TOLERANCE
     }
 }