Merge branch 'zesterer/worldgen' into 'master'

Worldgen improvements

See merge request veloren/veloren!457

assets/voxygen/shaders/postprocess-frag.glsl

@@ -170,7 +170,7 @@ void main() {
 	hsva_color.y *= 1.45;
 	hsva_color.z *= 0.85;
 	//hsva_color.z = 1.0 - 1.0 / (1.0 * hsva_color.z + 1.0);
-	vec4 final_color = fxaa_color; 
+	vec4 final_color = fxaa_color;
     //vec4 final_color = vec4(hsv2rgb(hsva_color.rgb), hsva_color.a);
 
 	tgt_color = vec4(final_color.rgb, 1);

assets/voxygen/shaders/terrain-vert.glsl

@@ -47,4 +47,4 @@ void main() {
 		proj_mat *
 		view_mat *
 		vec4(f_pos, 1);
-}
+}

server-cli/.gitignore

@@ -0,0 +1 @@
+settings.ron

voxygen/src/mesh/terrain.rs

@@ -104,8 +104,8 @@ impl<V: BaseVol<Vox = Block> + ReadVol + Debug, S: VolSize + Clone>
                                 .map(|vox| block_shadow_density(vox.kind()))
                                 .unwrap_or((0.0, 0.0));
 
-                            neighbour_light[0][i][j] =
-                                (neighbour_light[0][i][j] * (1.0 - density)).max(cap);
+                            neighbour_light[0][i][j] = (neighbour_light[0][i][j] * (1.0 - density))
+                                .max(cap.min(neighbour_light[1][i][j]));
                         }
                     }
 

voxygen/src/scene/terrain.rs

@@ -608,11 +608,9 @@ impl Terrain {
             }
         }
 
-        // Translucent
+        // Terrain sprites
         for (pos, chunk) in &self.chunks {
             if chunk.visible {
-                renderer.render_fluid_chunk(&chunk.fluid_model, globals, &chunk.locals, lights);
-
                 const SPRITE_RENDER_DISTANCE: f32 = 128.0;
 
                 let chunk_center = pos.map2(Vec2::from(TerrainChunkSize::SIZE), |e, sz: u32| {
@@ -632,5 +630,12 @@ impl Terrain {
                 }
             }
         }
+
+        // Translucent
+        for (_, chunk) in &self.chunks {
+            if chunk.visible {
+                renderer.render_fluid_chunk(&chunk.fluid_model, globals, &chunk.locals, lights);
+            }
+        }
     }
 }

world/src/block/mod.rs

@@ -2,6 +2,7 @@ mod natural;
 
 use crate::{
     column::{ColumnGen, ColumnSample, StructureData},
+    generator::{Generator, TownGen},
     util::{HashCache, RandomField, Sampler, SamplerMut},
     World, CONFIG,
 };
@@ -136,6 +137,7 @@ impl<'a> BlockGen<'a> {
             column_gen,
         } = self;
 
+        let sample = &z_cache?.sample;
         let &ColumnSample {
             alt,
             chaos,
@@ -155,8 +157,10 @@ impl<'a> BlockGen<'a> {
             cliff_hill,
             close_cliffs,
             temp,
+
+            chunk,
             ..
-        } = &z_cache?.sample;
+        } = sample;
 
         let structures = &z_cache?.structures;
 
@@ -168,31 +172,21 @@ impl<'a> BlockGen<'a> {
                 (true, alt, CONFIG.sea_level /*water_level*/)
             } else {
                 // Apply warping
-                let warp = (world
-                    .sim()
-                    .gen_ctx
-                    .warp_nz
-                    .get((wposf.div(Vec3::new(150.0, 150.0, 150.0))).into_array())
-                    as f32)
+                let warp = (world.sim().gen_ctx.warp_nz.get(wposf.div(48.0)) as f32)
                     .mul((chaos - 0.1).max(0.0))
-                    .mul(96.0);
+                    .mul(48.0)
+                    + (world.sim().gen_ctx.warp_nz.get(wposf.div(15.0)) as f32)
+                        .mul((chaos - 0.1).max(0.0))
+                        .mul(24.0);
 
                 let height = if (wposf.z as f32) < alt + warp - 10.0 {
                     // Shortcut cliffs
                     alt + warp
                 } else {
                     let turb = Vec2::new(
-                        world
-                            .sim()
-                            .gen_ctx
-                            .turb_x_nz
-                            .get((wposf.div(48.0)).into_array()) as f32,
-                        world
-                            .sim()
-                            .gen_ctx
-                            .turb_y_nz
-                            .get((wposf.div(48.0)).into_array()) as f32,
-                    ) * 12.0;
+                        world.sim().gen_ctx.fast_turb_x_nz.get(wposf.div(25.0)) as f32,
+                        world.sim().gen_ctx.fast_turb_y_nz.get(wposf.div(25.0)) as f32,
+                    ) * 8.0;
 
                     let wpos_turb = Vec2::from(wpos).map(|e: i32| e as f32) + turb;
                     let cliff_height = Self::get_cliff_height(
@@ -352,6 +346,14 @@ impl<'a> BlockGen<'a> {
             }
         });
 
+        // Structures (like towns)
+        let block = chunk
+            .structures
+            .town
+            .as_ref()
+            .and_then(|town| TownGen.get((town, wpos, sample, height)))
+            .or(block);
+
         let block = structures
             .iter()
             .find_map(|st| {
@@ -406,11 +408,24 @@ impl<'a> ZCache<'a> {
             .max(self.sample.water_level)
             .max(CONFIG.sea_level + 2.0);
 
+        // Structures
+        let (min, max) = self
+            .sample
+            .chunk
+            .structures
+            .town
+            .as_ref()
+            .map(|town| {
+                let (town_min, town_max) = TownGen.get_z_limits(town, self.wpos, &self.sample);
+                (town_min.min(min), town_max.max(max))
+            })
+            .unwrap_or((min, max));
+
         (min, max)
     }
 }
 
-impl<'a> SamplerMut for BlockGen<'a> {
+impl<'a> SamplerMut<'static> for BlockGen<'a> {
     type Index = Vec3<i32>;
     type Sample = Option<Block>;
 
@@ -499,7 +514,7 @@ impl StructureInfo {
     }
 }
 
-fn block_from_structure(
+pub fn block_from_structure(
     sblock: StructureBlock,
     default_kind: BlockKind,
     pos: Vec3<i32>,

world/src/block/natural.rs

@@ -30,6 +30,7 @@ pub fn structure_gen<'a>(
     if (st_sample.tree_density as f64) < random_seed
         || st_sample.alt < st_sample.water_level
         || st_sample.spawn_rate < 0.5
+        || !st_sample.spawn_rules.trees
     {
         return None;
     }

world/src/column/mod.rs

@@ -1,7 +1,8 @@
 use crate::{
     all::ForestKind,
     block::StructureMeta,
-    sim::{LocationInfo, SimChunk},
+    generator::{Generator, SpawnRules, TownGen},
+    sim::{LocationInfo, SimChunk, WorldSim},
     util::{RandomPerm, Sampler, UnitChooser},
     World, CONFIG,
 };
@@ -20,7 +21,7 @@ use std::{
 use vek::*;
 
 pub struct ColumnGen<'a> {
-    world: &'a World,
+    pub sim: &'a WorldSim,
 }
 
 static UNIT_CHOOSER: UnitChooser = UnitChooser::new(0x700F4EC7);
@@ -55,14 +56,13 @@ lazy_static! {
 }
 
 impl<'a> ColumnGen<'a> {
-    pub fn new(world: &'a World) -> Self {
-        Self { world }
+    pub fn new(sim: &'a WorldSim) -> Self {
+        Self { sim }
     }
 
     fn get_local_structure(&self, wpos: Vec2<i32>) -> Option<StructureData> {
         let (pos, seed) = self
-            .world
-            .sim()
+            .sim
             .gen_ctx
             .region_gen
             .get(wpos)
@@ -74,7 +74,7 @@ impl<'a> ColumnGen<'a> {
         let chunk_pos = pos.map2(Vec2::from(TerrainChunkSize::SIZE), |e, sz: u32| {
             e / sz as i32
         });
-        let chunk = self.world.sim().get(chunk_pos)?;
+        let chunk = self.sim.get(chunk_pos)?;
 
         if seed % 5 == 2
             && chunk.temp > CONFIG.desert_temp
@@ -102,8 +102,7 @@ impl<'a> ColumnGen<'a> {
 
     fn gen_close_structures(&self, wpos: Vec2<i32>) -> [Option<StructureData>; 9] {
         let mut metas = [None; 9];
-        self.world
-            .sim()
+        self.sim
             .gen_ctx
             .structure_gen
             .get(wpos)
@@ -121,7 +120,7 @@ impl<'a> ColumnGen<'a> {
     }
 }
 
-impl<'a> Sampler for ColumnGen<'a> {
+impl<'a> Sampler<'a> for ColumnGen<'a> {
     type Index = Vec2<i32>;
     type Sample = Option<ColumnSample<'a>>;
 
@@ -131,7 +130,7 @@ impl<'a> Sampler for ColumnGen<'a> {
             e / sz as i32
         });
 
-        let sim = self.world.sim();
+        let sim = &self.sim;
 
         let turb = Vec2::new(
             sim.gen_ctx.turb_x_nz.get((wposf.div(48.0)).into_array()) as f32,
@@ -142,7 +141,6 @@ impl<'a> Sampler for ColumnGen<'a> {
         let alt_base = sim.get_interpolated(wpos, |chunk| chunk.alt_base)?;
         let chaos = sim.get_interpolated(wpos, |chunk| chunk.chaos)?;
         let temp = sim.get_interpolated(wpos, |chunk| chunk.temp)?;
-        let dryness = sim.get_interpolated(wpos, |chunk| chunk.dryness)?;
         let humidity = sim.get_interpolated(wpos, |chunk| chunk.humidity)?;
         let rockiness = sim.get_interpolated(wpos, |chunk| chunk.rockiness)?;
         let tree_density = sim.get_interpolated(wpos, |chunk| chunk.tree_density)?;
@@ -175,8 +173,16 @@ impl<'a> Sampler for ColumnGen<'a> {
                 .small_nz
                 .get((wposf_turb.div(150.0)).into_array()) as f32)
                 .abs()
-                .mul(chaos.max(0.15))
-                .mul(64.0);
+                .mul(chaos.max(0.025))
+                .mul(64.0)
+            + (sim
+                .gen_ctx
+                .small_nz
+                .get((wposf_turb.div(450.0)).into_array()) as f32)
+                .abs()
+                .mul(1.0 - chaos)
+                .mul(1.0 - humidity)
+                .mul(96.0);
 
         let is_cliffs = sim_chunk.is_cliffs;
         let near_cliffs = sim_chunk.near_cliffs;
@@ -376,6 +382,7 @@ impl<'a> Sampler for ColumnGen<'a> {
                 .add((marble_small - 0.5) * 0.5),
         );
 
+        /*
         // Work out if we're on a path or near a town
         let dist_to_path = match &sim_chunk.location {
             Some(loc) => {
@@ -412,9 +419,11 @@ impl<'a> Sampler for ColumnGen<'a> {
         } else {
             (alt, ground)
         };
+        */
 
         // Cities
         // TODO: In a later MR
+        /*
         let building = match &sim_chunk.location {
             Some(loc) => {
                 let loc = &sim.locations[loc.loc_idx];
@@ -433,6 +442,7 @@ impl<'a> Sampler for ColumnGen<'a> {
         };
 
         let alt = alt + building;
+        */
 
         // Caves
         let cave_at = |wposf: Vec2<f64>| {
@@ -507,6 +517,14 @@ impl<'a> Sampler for ColumnGen<'a> {
             temp,
             spawn_rate,
             location: sim_chunk.location.as_ref(),
+
+            chunk: sim_chunk,
+            spawn_rules: sim_chunk
+                .structures
+                .town
+                .as_ref()
+                .map(|town| TownGen.spawn_rules(town, wpos))
+                .unwrap_or(SpawnRules::default()),
         })
     }
 }
@@ -534,6 +552,9 @@ pub struct ColumnSample<'a> {
     pub temp: f32,
     pub spawn_rate: f32,
     pub location: Option<&'a LocationInfo>,
+
+    pub chunk: &'a SimChunk,
+    pub spawn_rules: SpawnRules,
 }
 
 #[derive(Copy, Clone)]

world/src/generator/mod.rs

@@ -0,0 +1,34 @@
+mod town;
+
+// Reexports
+pub use self::town::{TownGen, TownState};
+
+use crate::{column::ColumnSample, util::Sampler};
+use common::terrain::Block;
+use vek::*;
+
+#[derive(Copy, Clone, Debug)]
+pub struct SpawnRules {
+    pub trees: bool,
+}
+
+impl Default for SpawnRules {
+    fn default() -> Self {
+        Self { trees: true }
+    }
+}
+
+impl SpawnRules {
+    pub fn and(self, other: Self) -> Self {
+        Self {
+            trees: self.trees && other.trees,
+        }
+    }
+}
+
+pub trait Generator<'a, T: 'a>:
+    Sampler<'a, Index = (&'a T, Vec3<i32>, &'a ColumnSample<'a>, f32), Sample = Option<Block>>
+{
+    fn get_z_limits(&self, state: &'a T, wpos: Vec2<i32>, sample: &ColumnSample) -> (f32, f32);
+    fn spawn_rules(&self, town: &'a TownState, wpos: Vec2<i32>) -> SpawnRules;
+}

world/src/generator/town/mod.rs

@@ -0,0 +1,655 @@
+mod util;
+mod vol;
+
+use super::{Generator, SpawnRules};
+use crate::{
+    block::block_from_structure,
+    column::{ColumnGen, ColumnSample},
+    sim::WorldSim,
+    util::{seed_expan, Grid, Sampler, UnitChooser},
+};
+use common::{
+    assets,
+    terrain::{Block, BlockKind, Structure},
+    vol::{ReadVol, Vox, WriteVol},
+};
+use hashbrown::HashSet;
+use lazy_static::lazy_static;
+use rand::prelude::*;
+use rand_chacha::ChaChaRng;
+use std::{ops::Add, sync::Arc};
+use vek::*;
+
+use self::vol::{CellKind, ColumnKind, Module, TownCell, TownColumn, TownVol};
+
+const CELL_SIZE: i32 = 9;
+const CELL_HEIGHT: i32 = 9;
+
+pub struct TownGen;
+
+impl<'a> Sampler<'a> for TownGen {
+    type Index = (&'a TownState, Vec3<i32>, &'a ColumnSample<'a>, f32);
+    type Sample = Option<Block>;
+
+    fn get(&self, (town, wpos, sample, height): Self::Index) -> Self::Sample {
+        let cell_pos = (wpos - town.center)
+            .map2(Vec3::new(CELL_SIZE, CELL_SIZE, CELL_HEIGHT), |e, sz| {
+                e.div_euclid(sz)
+            })
+            .add(Vec3::from(town.vol.size() / 2));
+        let inner_pos = (wpos - town.center)
+            .map2(Vec3::new(CELL_SIZE, CELL_SIZE, CELL_HEIGHT), |e, sz| {
+                e.rem_euclid(sz)
+            });
+
+        let cell = town.vol.get(cell_pos).ok()?;
+
+        match (modules_from_kind(&cell.kind), &cell.module) {
+            (Some(module_list), Some(module)) => {
+                let transform = [
+                    (Vec2::new(0, 0), Vec2::unit_x(), Vec2::unit_y()),
+                    (Vec2::new(0, 1), -Vec2::unit_y(), Vec2::unit_x()),
+                    (Vec2::new(1, 1), -Vec2::unit_x(), -Vec2::unit_y()),
+                    (Vec2::new(1, 0), Vec2::unit_y(), -Vec2::unit_x()),
+                ];
+
+                module_list[module.vol_idx]
+                    .0
+                    .get(
+                        Vec3::from(
+                            transform[module.dir].0 * (CELL_SIZE - 1)
+                                + transform[module.dir].1 * inner_pos.x
+                                + transform[module.dir].2 * inner_pos.y,
+                        ) + Vec3::unit_z() * inner_pos.z,
+                    )
+                    .ok()
+                    .and_then(|sb| {
+                        block_from_structure(*sb, BlockKind::Normal, wpos, wpos.into(), 0, sample)
+                    })
+            }
+            _ => match cell.kind {
+                CellKind::Empty => None,
+                CellKind::Park => None,
+                CellKind::Rock => Some(Block::new(BlockKind::Normal, Rgb::broadcast(100))),
+                CellKind::Wall => Some(Block::new(BlockKind::Normal, Rgb::broadcast(175))),
+                CellKind::Road => {
+                    if (wpos.z as f32) < height - 1.0 {
+                        Some(Block::new(
+                            BlockKind::Normal,
+                            Lerp::lerp(
+                                Rgb::new(150.0, 140.0, 50.0),
+                                Rgb::new(100.0, 95.0, 30.0),
+                                sample.marble_small,
+                            )
+                            .map(|e| e as u8),
+                        ))
+                    } else {
+                        Some(Block::empty())
+                    }
+                }
+                CellKind::House(idx) => Some(Block::new(BlockKind::Normal, town.houses[idx].color)),
+            },
+        }
+    }
+}
+
+impl<'a> Generator<'a, TownState> for TownGen {
+    fn get_z_limits(
+        &self,
+        town: &'a TownState,
+        wpos: Vec2<i32>,
+        sample: &ColumnSample,
+    ) -> (f32, f32) {
+        (sample.alt - 32.0, sample.alt + 75.0)
+    }
+
+    fn spawn_rules(&self, town: &'a TownState, wpos: Vec2<i32>) -> SpawnRules {
+        SpawnRules { trees: false }
+    }
+}
+
+struct House {
+    color: Rgb<u8>,
+}
+
+pub struct TownState {
+    center: Vec3<i32>,
+    radius: i32,
+    vol: TownVol,
+    houses: Vec<House>,
+}
+
+impl TownState {
+    pub fn generate(center: Vec2<i32>, gen: &mut ColumnGen, rng: &mut impl Rng) -> Option<Self> {
+        let radius = rng.gen_range(18, 20) * 9;
+        let size = Vec2::broadcast(radius * 2 / 9 - 2);
+
+        let alt = gen.get(center).map(|sample| sample.alt).unwrap_or(0.0) as i32;
+
+        let mut vol = TownVol::generate_from(
+            size,
+            |pos| {
+                let wpos = center + (pos - size / 2) * CELL_SIZE + CELL_SIZE / 2;
+                let rel_alt = gen.get(wpos).map(|sample| sample.alt).unwrap_or(0.0) as i32
+                    + CELL_HEIGHT / 2
+                    - alt;
+
+                let col = TownColumn {
+                    ground: rel_alt.div_euclid(CELL_HEIGHT),
+                    kind: None,
+                };
+
+                (col.ground, col)
+            },
+            |(col, pos)| {
+                if pos.z >= col.ground {
+                    TownCell::empty()
+                } else {
+                    TownCell::from(CellKind::Rock)
+                }
+            },
+        );
+
+        // Generation passes
+        vol.setup(rng);
+        vol.gen_roads(rng, 30);
+        vol.gen_parks(rng, 3);
+        vol.emplace_columns();
+        let houses = vol.gen_houses(rng, 50);
+        vol.gen_walls(rng);
+        vol.resolve_modules(rng);
+        vol.cull_unused();
+
+        Some(Self {
+            center: Vec3::new(center.x, center.y, alt),
+            radius,
+            vol,
+            houses,
+        })
+    }
+
+    pub fn center(&self) -> Vec3<i32> {
+        self.center
+    }
+
+    pub fn radius(&self) -> i32 {
+        self.radius
+    }
+}
+
+impl TownVol {
+    fn floodfill(
+        &self,
+        limit: Option<usize>,
+        mut opens: HashSet<Vec2<i32>>,
+        mut f: impl FnMut(Vec2<i32>, &TownColumn) -> bool,
+    ) -> HashSet<Vec2<i32>> {
+        let mut closed = HashSet::new();
+
+        while opens.len() > 0 {
+            let mut new_opens = HashSet::new();
+
+            'search: for open in opens.iter() {
+                for i in -1..2 {
+                    for j in -1..2 {
+                        let pos = *open + Vec2::new(i, j);
+
+                        if let Some(col) = self.col(pos) {
+                            if !closed.contains(&pos) && !opens.contains(&pos) && f(pos, col) {
+                                match limit {
+                                    Some(limit)
+                                        if limit
+                                            <= new_opens.len() + closed.len() + opens.len() =>
+                                    {
+                                        break 'search
+                                    }
+                                    _ => {
+                                        new_opens.insert(pos);
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+
+            closed = closed.union(&opens).copied().collect();
+            opens = new_opens;
+        }
+
+        closed
+    }
+
+    fn setup(&mut self, rng: &mut impl Rng) {
+        // Place a single road tile at first
+        let root_road = self
+            .size()
+            .map(|sz| (sz / 8) * 2 + rng.gen_range(0, sz / 4) * 2);
+        self.set_col_kind(root_road, Some(ColumnKind::Road));
+    }
+
+    fn gen_roads(&mut self, rng: &mut impl Rng, n: usize) {
+        const ATTEMPTS: usize = 5;
+
+        let mut junctions = HashSet::new();
+        junctions.insert(self.choose_column(rng, |_, col| col.is_road()).unwrap());
+
+        for road in 0..n {
+            for _ in 0..ATTEMPTS {
+                let start = *junctions.iter().choose(rng).unwrap();
+                //let start = self.choose_column(rng, |pos, col| pos.map(|e| e % 2 == 0).reduce_and() && col.is_road()).unwrap();
+                let dir = util::gen_dir(rng);
+
+                // If the direction we want to paint a path in is obstructed, abandon this attempt
+                if self
+                    .col(start + dir)
+                    .map(|col| !col.is_empty())
+                    .unwrap_or(true)
+                {
+                    continue;
+                }
+
+                // How long should this road be?
+                let len = rng.gen_range(1, 10) * 2 + 1;
+
+                // Paint the road until we hit an obstacle
+                let success = (1..len)
+                    .map(|i| start + dir * i)
+                    .try_for_each(|pos| {
+                        if self.col(pos).map(|col| col.is_empty()).unwrap_or(false) {
+                            self.set_col_kind(pos, Some(ColumnKind::Road));
+                            Ok(())
+                        } else {
+                            junctions.insert(pos);
+                            Err(())
+                        }
+                    })
+                    .is_ok();
+
+                if success {
+                    junctions.insert(start + dir * (len - 1));
+                }
+
+                break;
+            }
+        }
+    }
+
+    fn gen_parks(&mut self, rng: &mut impl Rng, n: usize) {
+        const ATTEMPTS: usize = 5;
+
+        for _ in 0..n {
+            for _ in 0..ATTEMPTS {
+                let start = self
+                    .choose_column(rng, |pos, col| {
+                        col.is_empty()
+                            && (0..4).any(|i| {
+                                self.col(pos + util::dir(i))
+                                    .map(|col| col.is_road())
+                                    .unwrap_or(false)
+                            })
+                    })
+                    .unwrap();
+
+                let mut park =
+                    self.floodfill(Some(16), [start].iter().copied().collect(), |_, col| {
+                        col.is_empty()
+                    });
+
+                if park.len() < 4 {
+                    continue;
+                }
+
+                for cell in park {
+                    self.set_col_kind(cell, Some(ColumnKind::Internal));
+                    let col = self.col(cell).unwrap();
+                    let ground = col.ground;
+                    for z in 0..2 {
+                        self.set(Vec3::new(cell.x, cell.y, ground + z), CellKind::Park.into());
+                    }
+                }
+
+                break;
+            }
+        }
+    }
+
+    fn gen_walls(&mut self, rng: &mut impl Rng) {
+        let mut outer = HashSet::new();
+        for i in 0..self.size().x {
+            outer.insert(Vec2::new(i, 0));
+            outer.insert(Vec2::new(i, self.size().y - 1));
+        }
+        for j in 0..self.size().y {
+            outer.insert(Vec2::new(0, j));
+            outer.insert(Vec2::new(self.size().x - 1, j));
+        }
+
+        let mut outer = self.floodfill(None, outer, |_, col| col.is_empty());
+
+        let mut walls = HashSet::new();
+        let inner = self.floodfill(
+            None,
+            [self.size() / 2].iter().copied().collect(),
+            |pos, _| {
+                if outer.contains(&pos) {
+                    walls.insert(pos);
+                    false
+                } else {
+                    true
+                }
+            },
+        );
+
+        while let Some(wall) = walls
+            .iter()
+            .filter(|pos| {
+                let lateral_count = (0..4)
+                    .filter(|i| walls.contains(&(**pos + util::dir(*i))))
+                    .count();
+                let max_quadrant_count = (0..4)
+                    .map(|i| {
+                        let units = util::unit(i);
+                        (0..2)
+                            .map(|i| (0..2).map(move |j| (i, j)))
+                            .flatten()
+                            .filter(|(i, j)| walls.contains(&(**pos + units.0 * *i + units.1 * *j)))
+                            .count()
+                    })
+                    .max()
+                    .unwrap();
+
+                lateral_count < 2 || (lateral_count == 2 && max_quadrant_count == 4)
+            })
+            .next()
+        {
+            let wall = *wall;
+            walls.remove(&wall);
+        }
+
+        for wall in walls.iter() {
+            let col = self.col(*wall).unwrap();
+            let ground = col.ground;
+            for z in -1..3 {
+                self.set(Vec3::new(wall.x, wall.y, ground + z), CellKind::Wall.into());
+            }
+        }
+    }
+
+    fn emplace_columns(&mut self) {
+        for i in 0..self.size().x {
+            for j in 0..self.size().y {
+                let col = self.col(Vec2::new(i, j)).unwrap();
+                let ground = col.ground;
+
+                match col.kind {
+                    None => {}
+                    Some(ColumnKind::Internal) => {}
+                    Some(ColumnKind::External) => {}
+                    Some(ColumnKind::Road) => {
+                        for z in -1..2 {
+                            self.set(Vec3::new(i, j, ground + z), CellKind::Road.into());
+                        }
+                    }
+                    _ => unimplemented!(),
+                }
+            }
+        }
+    }
+
+    fn gen_houses(&mut self, rng: &mut impl Rng, n: usize) -> Vec<House> {
+        const ATTEMPTS: usize = 10;
+
+        let mut houses = Vec::new();
+        for _ in 0..n {
+            for _ in 0..ATTEMPTS {
+                let entrance = {
+                    let start = self.choose_cell(rng, |_, cell| cell.is_road()).unwrap();
+                    let dir = Vec3::from(util::gen_dir(rng));
+
+                    if self
+                        .get(start + dir)
+                        .map(|col| !col.is_empty())
+                        .unwrap_or(true)
+                        || self
+                            .get(start + dir - Vec3::unit_z())
+                            .map(|col| !col.is_foundation())
+                            .unwrap_or(true)
+                    {
+                        continue;
+                    } else {
+                        start + dir
+                    }
+                };
+
+                let mut cells: HashSet<_> = Some(entrance).into_iter().collect();
+
+                let mut energy = 1000;
+                while energy > 0 {
+                    energy -= 1;
+
+                    let parent = *cells.iter().choose(rng).unwrap();
+                    let dir = util::UNITS_3D
+                        .choose_weighted(rng, |pos| 1 + pos.z.max(0))
+                        .unwrap();
+
+                    if self
+                        .get(parent + dir)
+                        .map(|cell| cell.is_empty())
+                        .unwrap_or(false)
+                        && self
+                            .get(parent + dir - Vec3::unit_z())
+                            .map(|cell| {
+                                cell.is_foundation()
+                                    || cells.contains(&(parent + dir - Vec3::unit_z()))
+                            })
+                            .unwrap_or(false)
+                    {
+                        cells.insert(parent + dir);
+                        energy -= 10;
+                    }
+                }
+
+                // Remove cells that are too isolated
+                loop {
+                    let cells_copy = cells.clone();
+
+                    let mut any_removed = false;
+                    cells.retain(|pos| {
+                        let neighbour_count = (0..6)
+                            .filter(|i| {
+                                let neighbour = pos + util::dir_3d(*i);
+                                cells_copy.contains(&neighbour)
+                            })
+                            .count();
+
+                        if neighbour_count < 3 {
+                            any_removed = true;
+                            false
+                        } else {
+                            true
+                        }
+                    });
+
+                    if !any_removed {
+                        break;
+                    }
+                }
+
+                // Get rid of houses that are too small
+                if cells.len() < 6 {
+                    continue;
+                }
+
+                for cell in cells {
+                    self.set(cell, CellKind::House(houses.len()).into());
+                    self.set_col_kind(Vec2::from(cell), Some(ColumnKind::Internal));
+                }
+
+                houses.push(House {
+                    color: Rgb::new(rng.gen(), rng.gen(), rng.gen()),
+                });
+            }
+        }
+
+        houses
+    }
+
+    fn cull_unused(&mut self) {
+        for x in 0..self.size().x {
+            for y in 0..self.size().y {
+                for z in self.col_range(Vec2::new(x, y)).unwrap().rev() {
+                    let pos = Vec3::new(x, y, z);
+
+                    // Remove foundations that don't have anything on top of them
+                    if self.get(pos).unwrap().is_foundation()
+                        && self
+                            .get(pos + Vec3::unit_z())
+                            .map(TownCell::is_space)
+                            .unwrap_or(true)
+                    {
+                        self.set(pos, TownCell::empty());
+                    }
+                }
+            }
+        }
+    }
+
+    fn resolve_modules(&mut self, rng: &mut impl Rng) {
+        fn classify(cell: &TownCell, this_cell: &TownCell) -> ModuleKind {
+            match (&cell.kind, &this_cell.kind) {
+                (CellKind::House(a), CellKind::House(b)) if a == b => ModuleKind::This,
+                (CellKind::Wall, CellKind::Wall) => ModuleKind::This,
+                _ => ModuleKind::That,
+            }
+        }
+
+        for x in 0..self.size().x {
+            for y in 0..self.size().y {
+                for z in self.col_range(Vec2::new(x, y)).unwrap() {
+                    let pos = Vec3::new(x, y, z);
+                    let this_cell = if let Ok(this_cell) = self.get(pos) {
+                        this_cell
+                    } else {
+                        continue;
+                    };
+
+                    let mut signature = [ModuleKind::That; 6];
+                    for i in 0..6 {
+                        signature[i] = self
+                            .get(pos + util::dir_3d(i))
+                            .map(|cell| classify(cell, this_cell))
+                            .unwrap_or(ModuleKind::That);
+                    }
+
+                    let module_list = if let Some(modules) = modules_from_kind(&this_cell.kind) {
+                        modules
+                    } else {
+                        continue;
+                    };
+
+                    let module = module_list
+                        .iter()
+                        .enumerate()
+                        .filter_map(|(i, module)| {
+                            let perms = [[0, 1, 2, 3], [3, 0, 1, 2], [2, 3, 0, 1], [1, 2, 3, 0]];
+
+                            let mut rotated_signature = [ModuleKind::That; 6];
+                            for (dir, perm) in perms.iter().enumerate() {
+                                rotated_signature[perm[0]] = signature[0];
+                                rotated_signature[perm[1]] = signature[1];
+                                rotated_signature[perm[2]] = signature[2];
+                                rotated_signature[perm[3]] = signature[3];
+                                rotated_signature[4] = signature[4];
+                                rotated_signature[5] = signature[5];
+
+                                if &module.1[0..6] == &rotated_signature[0..6] {
+                                    return Some(Module { vol_idx: i, dir });
+                                }
+                            }
+
+                            None
+                        })
+                        .choose(rng);
+
+                    if let Some(module) = module {
+                        let kind = this_cell.kind.clone();
+                        self.set(
+                            pos,
+                            TownCell {
+                                kind,
+                                module: Some(module),
+                            },
+                        );
+                    }
+                }
+            }
+        }
+    }
+}
+
+#[derive(Copy, Clone, PartialEq)]
+pub enum ModuleKind {
+    This,
+    That,
+}
+
+fn module(name: &str, sig: [ModuleKind; 6]) -> (Arc<Structure>, [ModuleKind; 6]) {
+    (
+        assets::load(&format!("world.module.{}", name)).unwrap(),
+        sig,
+    )
+}
+
+fn modules_from_kind(kind: &CellKind) -> Option<&'static [(Arc<Structure>, [ModuleKind; 6])]> {
+    match kind {
+        CellKind::House(_) => Some(&HOUSE_MODULES),
+        CellKind::Wall => Some(&WALL_MODULES),
+        _ => None,
+    }
+}
+
+lazy_static! {
+    pub static ref HOUSE_MODULES: Vec<(Arc<Structure>, [ModuleKind; 6])> = {
+        use ModuleKind::*;
+        vec![
+            module("human.floor_ground", [This, This, This, This, This, That]),
+            module("human.stair_ground", [This, This, This, This, This, That]),
+            module("human.corner_ground", [This, This, That, That, This, That]),
+            module("human.wall_ground", [This, This, This, That, This, That]),
+            module("human.door_ground", [This, This, This, That, This, That]),
+            module("human.window_ground", [This, This, This, That, This, That]),
+            module("human.floor_roof", [This, This, This, This, That, This]),
+            module("human.corner_roof", [This, This, That, That, That, This]),
+            module("human.chimney_roof", [This, This, That, That, That, This]),
+            module("human.wall_roof", [This, This, This, That, That, This]),
+            module("human.floor_upstairs", [This, This, This, This, This, This]),
+            module(
+                "human.balcony_upstairs",
+                [This, This, This, This, This, This],
+            ),
+            module(
+                "human.corner_upstairs",
+                [This, This, That, That, This, This],
+            ),
+            module("human.wall_upstairs", [This, This, This, That, This, This]),
+            module(
+                "human.window_upstairs",
+                [This, This, This, That, This, This],
+            ),
+        ]
+    };
+    pub static ref WALL_MODULES: Vec<(Arc<Structure>, [ModuleKind; 6])> = {
+        use ModuleKind::*;
+        vec![
+            module("wall.edge_ground", [This, That, This, That, This, That]),
+            module("wall.edge_mid", [This, That, This, That, This, This]),
+            module("wall.edge_top", [This, That, This, That, That, This]),
+            module("wall.corner_ground", [This, This, That, That, This, That]),
+            module("wall.corner_mid", [This, This, That, That, This, This]),
+            module("wall.corner_top", [This, This, That, That, That, This]),
+            module("wall.end_top", [That, This, That, That, That, This]),
+            module("wall.single_top", [That, That, That, That, That, This]),
+        ]
+    };
+}

world/src/generator/town/util.rs

@@ -0,0 +1,42 @@
+use rand::prelude::*;
+use vek::*;
+
+pub const UNITS: [Vec2<i32>; 4] = [
+    Vec2 { x: 1, y: 0 },
+    Vec2 { x: 0, y: 1 },
+    Vec2 { x: -1, y: 0 },
+    Vec2 { x: 0, y: -1 },
+];
+
+pub fn dir(i: usize) -> Vec2<i32> {
+    UNITS[i % 4]
+}
+
+pub fn unit(i: usize) -> (Vec2<i32>, Vec2<i32>) {
+    (UNITS[i % 4], UNITS[(i + 1) % 4])
+}
+
+pub fn gen_unit(rng: &mut impl Rng) -> (Vec2<i32>, Vec2<i32>) {
+    unit(rng.gen_range(0, 4))
+}
+
+pub fn gen_dir(rng: &mut impl Rng) -> Vec2<i32> {
+    UNITS[rng.gen_range(0, 4)]
+}
+
+pub const UNITS_3D: [Vec3<i32>; 6] = [
+    Vec3 { x: 1, y: 0, z: 0 },
+    Vec3 { x: 0, y: 1, z: 0 },
+    Vec3 { x: -1, y: 0, z: 0 },
+    Vec3 { x: 0, y: -1, z: 0 },
+    Vec3 { x: 0, y: 0, z: 1 },
+    Vec3 { x: 0, y: 0, z: -1 },
+];
+
+pub fn dir_3d(i: usize) -> Vec3<i32> {
+    UNITS_3D[i % 6]
+}
+
+pub fn gen_dir_3d(rng: &mut impl Rng) -> Vec3<i32> {
+    UNITS_3D[rng.gen_range(0, 6)]
+}

world/src/generator/town/vol.rs

@@ -0,0 +1,227 @@
+use crate::util::Grid;
+use common::vol::{BaseVol, ReadVol, Vox, WriteVol};
+use rand::prelude::*;
+use std::ops::Range;
+use vek::*;
+
+#[derive(Clone)]
+pub enum ColumnKind {
+    Road,
+    Wall,
+    Internal,
+    External, // Outside the boundary wall
+}
+
+#[derive(Clone, Default)]
+pub struct TownColumn {
+    pub ground: i32,
+    pub kind: Option<ColumnKind>,
+}
+
+impl TownColumn {
+    pub fn is_empty(&self) -> bool {
+        self.kind.is_none()
+    }
+
+    pub fn is_road(&self) -> bool {
+        self.kind
+            .as_ref()
+            .map(|kind| match kind {
+                ColumnKind::Road => true,
+                _ => false,
+            })
+            .unwrap_or(false)
+    }
+}
+
+#[derive(Clone)]
+pub struct Module {
+    pub vol_idx: usize,
+    pub dir: usize,
+}
+
+#[derive(Clone)]
+pub enum CellKind {
+    Empty,
+    Park,
+    Rock,
+    Road,
+    Wall,
+    House(usize),
+}
+
+#[derive(Clone)]
+pub struct TownCell {
+    pub kind: CellKind,
+    pub module: Option<Module>,
+}
+
+impl TownCell {
+    pub fn is_road(&self) -> bool {
+        match self.kind {
+            CellKind::Road => true,
+            _ => false,
+        }
+    }
+
+    pub fn is_space(&self) -> bool {
+        match self.kind {
+            CellKind::Empty => true,
+            CellKind::Park => true,
+            CellKind::Road => true,
+            _ => false,
+        }
+    }
+
+    pub fn is_foundation(&self) -> bool {
+        match self.kind {
+            CellKind::Rock => true,
+            _ => false,
+        }
+    }
+}
+
+impl Vox for TownCell {
+    fn empty() -> Self {
+        Self {
+            kind: CellKind::Empty,
+            module: None,
+        }
+    }
+
+    fn is_empty(&self) -> bool {
+        match self.kind {
+            CellKind::Empty => true,
+            _ => false,
+        }
+    }
+}
+
+impl From<CellKind> for TownCell {
+    fn from(kind: CellKind) -> Self {
+        Self { kind, module: None }
+    }
+}
+
+#[derive(Debug)]
+pub enum TownError {
+    OutOfBounds,
+}
+
+const HEIGHT: usize = 24;
+const UNDERGROUND_DEPTH: i32 = 5;
+
+type GridItem = (i32, TownColumn, Vec<TownCell>);
+
+pub struct TownVol {
+    grid: Grid<GridItem>,
+}
+
+impl TownVol {
+    pub fn generate_from(
+        size: Vec2<i32>,
+        mut f: impl FnMut(Vec2<i32>) -> (i32, TownColumn),
+        mut g: impl FnMut((&TownColumn, Vec3<i32>)) -> TownCell,
+    ) -> Self {
+        let mut this = Self {
+            grid: Grid::new(
+                (0, TownColumn::default(), vec![TownCell::empty(); HEIGHT]),
+                size,
+            ),
+        };
+
+        for (pos, (base, col, cells)) in this.grid.iter_mut() {
+            let column = f(pos);
+            *base = column.0;
+            *col = column.1;
+            for z in 0..HEIGHT {
+                cells[z] = g((
+                    col,
+                    Vec3::new(pos.x, pos.y, *base - UNDERGROUND_DEPTH + z as i32),
+                ));
+            }
+        }
+
+        this
+    }
+
+    pub fn size(&self) -> Vec2<i32> {
+        self.grid.size()
+    }
+
+    pub fn set_col_kind(&mut self, pos: Vec2<i32>, kind: Option<ColumnKind>) {
+        self.grid.get_mut(pos).map(|col| col.1.kind = kind);
+    }
+
+    pub fn col(&self, pos: Vec2<i32>) -> Option<&TownColumn> {
+        self.grid.get(pos).map(|col| &col.1)
+    }
+
+    pub fn col_range(&self, pos: Vec2<i32>) -> Option<Range<i32>> {
+        self.grid.get(pos).map(|col| {
+            let lower = col.0 - UNDERGROUND_DEPTH;
+            lower..lower + HEIGHT as i32
+        })
+    }
+
+    pub fn choose_column(
+        &self,
+        rng: &mut impl Rng,
+        mut f: impl FnMut(Vec2<i32>, &TownColumn) -> bool,
+    ) -> Option<Vec2<i32>> {
+        self.grid
+            .iter()
+            .filter(|(pos, col)| f(*pos, &col.1))
+            .choose(rng)
+            .map(|(pos, _)| pos)
+    }
+
+    pub fn choose_cell(
+        &self,
+        rng: &mut impl Rng,
+        mut f: impl FnMut(Vec3<i32>, &TownCell) -> bool,
+    ) -> Option<Vec3<i32>> {
+        self.grid
+            .iter()
+            .map(|(pos, (base, _, cells))| {
+                cells.iter().enumerate().map(move |(i, cell)| {
+                    (
+                        Vec3::new(pos.x, pos.y, *base - UNDERGROUND_DEPTH + i as i32),
+                        cell,
+                    )
+                })
+            })
+            .flatten()
+            .filter(|(pos, cell)| f(*pos, *cell))
+            .choose(rng)
+            .map(|(pos, _)| pos)
+    }
+}
+
+impl BaseVol for TownVol {
+    type Vox = TownCell;
+    type Err = TownError;
+}
+
+impl ReadVol for TownVol {
+    fn get(&self, pos: Vec3<i32>) -> Result<&Self::Vox, Self::Err> {
+        match self.grid.get(Vec2::from(pos)) {
+            Some((base, _, cells)) => cells
+                .get((pos.z + UNDERGROUND_DEPTH - *base) as usize)
+                .ok_or(TownError::OutOfBounds),
+            None => Err(TownError::OutOfBounds),
+        }
+    }
+}
+
+impl WriteVol for TownVol {
+    fn set(&mut self, pos: Vec3<i32>, vox: Self::Vox) -> Result<(), Self::Err> {
+        match self.grid.get_mut(Vec2::from(pos)) {
+            Some((base, _, cells)) => cells
+                .get_mut((pos.z + UNDERGROUND_DEPTH - *base) as usize)
+                .map(|cell| *cell = vox)
+                .ok_or(TownError::OutOfBounds),
+            None => Err(TownError::OutOfBounds),
+        }
+    }
+}

world/src/lib.rs

@@ -3,13 +3,15 @@
     const_generics,
     euclidean_division,
     bind_by_move_pattern_guards,
-    option_flattening
+    option_flattening,
+    label_break_value
 )]
 
 mod all;
 mod block;
 mod column;
 pub mod config;
+pub mod generator;
 pub mod sim;
 pub mod util;
 
@@ -56,11 +58,11 @@ impl World {
     pub fn sample_columns(
         &self,
     ) -> impl Sampler<Index = Vec2<i32>, Sample = Option<ColumnSample>> + '_ {
-        ColumnGen::new(self)
+        ColumnGen::new(&self.sim)
     }
 
     pub fn sample_blocks(&self) -> BlockGen {
-        BlockGen::new(self, ColumnGen::new(self))
+        BlockGen::new(self, ColumnGen::new(&self.sim))
     }
 
     pub fn generate_chunk(&self, chunk_pos: Vec2<i32>) -> (TerrainChunk, ChunkSupplement) {

world/src/sim/mod.rs

@@ -11,7 +11,9 @@ use self::util::{
 
 use crate::{
     all::ForestKind,
-    util::{seed_expan, Sampler, StructureGen2d},
+    column::ColumnGen,
+    generator::TownState,
+    util::{seed_expan, FastNoise, Sampler, StructureGen2d},
     CONFIG,
 };
 use common::{
@@ -24,8 +26,10 @@ use noise::{
 use rand::{Rng, SeedableRng};
 use rand_chacha::ChaChaRng;
 use std::{
+    collections::HashMap,
     f32,
     ops::{Add, Div, Mul, Neg, Sub},
+    sync::Arc,
 };
 use vek::*;
 
@@ -73,7 +77,7 @@ pub(crate) struct GenCtx {
     pub small_nz: BasicMulti,
     pub rock_nz: HybridMulti,
     pub cliff_nz: HybridMulti,
-    pub warp_nz: BasicMulti,
+    pub warp_nz: FastNoise,
     pub tree_nz: BasicMulti,
 
     pub cave_0_nz: SuperSimplex,
@@ -82,6 +86,11 @@ pub(crate) struct GenCtx {
     pub structure_gen: StructureGen2d,
     pub region_gen: StructureGen2d,
     pub cliff_gen: StructureGen2d,
+
+    pub fast_turb_x_nz: FastNoise,
+    pub fast_turb_y_nz: FastNoise,
+
+    pub town_gen: StructureGen2d,
 }
 
 pub struct WorldSim {
@@ -115,7 +124,7 @@ impl WorldSim {
             small_nz: BasicMulti::new().set_octaves(2).set_seed(gen_seed()),
             rock_nz: HybridMulti::new().set_persistence(0.3).set_seed(gen_seed()),
             cliff_nz: HybridMulti::new().set_persistence(0.3).set_seed(gen_seed()),
-            warp_nz: BasicMulti::new().set_octaves(3).set_seed(gen_seed()),
+            warp_nz: FastNoise::new(gen_seed()), //BasicMulti::new().set_octaves(3).set_seed(gen_seed()),
             tree_nz: BasicMulti::new()
                 .set_octaves(12)
                 .set_persistence(0.75)
@@ -133,6 +142,11 @@ impl WorldSim {
                 // .set_octaves(6)
                 // .set_persistence(0.5)
                 .set_seed(gen_seed()),
+
+            fast_turb_x_nz: FastNoise::new(gen_seed()),
+            fast_turb_y_nz: FastNoise::new(gen_seed()),
+
+            town_gen: StructureGen2d::new(gen_seed(), 2048, 1024),
         };
 
         // "Base" of the chunk, to be multiplied by CONFIG.mountain_scale (multiplied value is
@@ -202,7 +216,7 @@ impl WorldSim {
                 // maximal at 0.  Also to be multiplied by CONFIG.mountain_scale.
                 let alt_main = (gen_ctx.alt_nz.get((wposf.div(2_000.0)).into_array()) as f32)
                     .abs()
-                    .powf(1.45);
+                    .powf(1.35);
 
                 (0.0 + alt_main
                     + (gen_ctx.small_nz.get((wposf.div(300.0)).into_array()) as f32)
@@ -410,6 +424,40 @@ impl WorldSim {
             }
         }
 
+        // Stage 2 - towns!
+        let mut maybe_towns = HashMap::new();
+        for i in 0..WORLD_SIZE.x {
+            for j in 0..WORLD_SIZE.y {
+                let chunk_pos = Vec2::new(i as i32, j as i32);
+                let wpos = chunk_pos.map2(Vec2::from(TerrainChunkSize::SIZE), |e, sz: u32| {
+                    e * sz as i32 + sz as i32 / 2
+                });
+
+                let near_towns = self.gen_ctx.town_gen.get(wpos);
+                let town = near_towns
+                    .iter()
+                    .min_by_key(|(pos, seed)| wpos.distance_squared(*pos));
+
+                if let Some((pos, _)) = town {
+                    let maybe_town = maybe_towns
+                        .entry(*pos)
+                        .or_insert_with(|| {
+                            TownState::generate(*pos, &mut ColumnGen::new(self), &mut rng)
+                                .map(|t| Arc::new(t))
+                        })
+                        .as_mut()
+                        // Only care if we're close to the town
+                        .filter(|town| {
+                            Vec2::from(town.center()).distance_squared(wpos)
+                                < town.radius().add(64).pow(2)
+                        })
+                        .cloned();
+
+                    self.get_mut(chunk_pos).unwrap().structures.town = maybe_town;
+                }
+            }
+        }
+
         self.rng = rng;
         self.locations = locations;
     }
@@ -425,6 +473,12 @@ impl WorldSim {
         }
     }
 
+    pub fn get_wpos(&self, wpos: Vec2<i32>) -> Option<&SimChunk> {
+        self.get(wpos.map2(Vec2::from(TerrainChunkSize::SIZE), |e, sz: u32| {
+            e / sz as i32
+        }))
+    }
+
     pub fn get_mut(&mut self, chunk_pos: Vec2<i32>) -> Option<&mut SimChunk> {
         if chunk_pos
             .map2(WORLD_SIZE, |e, sz| e >= 0 && e < sz as i32)
@@ -491,7 +545,6 @@ pub struct SimChunk {
     pub alt_base: f32,
     pub alt: f32,
     pub temp: f32,
-    pub dryness: f32,
     pub humidity: f32,
     pub rockiness: f32,
     pub is_cliffs: bool,
@@ -500,6 +553,8 @@ pub struct SimChunk {
     pub forest_kind: ForestKind,
     pub spawn_rate: f32,
     pub location: Option<LocationInfo>,
+
+    pub structures: Structures,
 }
 
 #[derive(Copy, Clone)]
@@ -516,27 +571,16 @@ pub struct LocationInfo {
     pub near: Vec<RegionInfo>,
 }
 
+#[derive(Clone)]
+pub struct Structures {
+    pub town: Option<Arc<TownState>>,
+}
+
 impl SimChunk {
     fn generate(posi: usize, gen_ctx: &mut GenCtx, gen_cdf: &GenCdf) -> Self {
         let pos = uniform_idx_as_vec2(posi);
         let wposf = (pos * TerrainChunkSize::SIZE.map(|e| e as i32)).map(|e| e as f64);
 
-        // FIXME: Currently unused, but should represent fresh groundwater level.
-        // Should be correlated a little with humidity, somewhat negatively with altitude,
-        // and very negatively with difference in temperature from zero.
-        let dryness = gen_ctx.dry_nz.get(
-            (wposf
-                .add(Vec2::new(
-                    gen_ctx
-                        .dry_nz
-                        .get((wposf.add(10000.0).div(500.0)).into_array())
-                        * 150.0,
-                    gen_ctx.dry_nz.get((wposf.add(0.0).div(500.0)).into_array()) * 150.0,
-                ))
-                .div(2_000.0))
-            .into_array(),
-        ) as f32;
-
         let (_, alt_base) = gen_cdf.alt_base[posi];
         let map_edge_factor = map_edge_factor(posi);
         let (_, chaos) = gen_cdf.chaos[posi];
@@ -606,17 +650,13 @@ impl SimChunk {
             alt_base,
             alt,
             temp,
-            dryness,
             humidity,
             rockiness: (gen_ctx.rock_nz.get((wposf.div(1024.0)).into_array()) as f32)
                 .sub(0.1)
                 .mul(1.3)
                 .max(0.0),
-            is_cliffs: cliff > 0.5
-                && dryness > 0.05
-                && alt > CONFIG.sea_level + 5.0
-                && dryness.abs() > 0.075,
-            near_cliffs: cliff > 0.25,
+            is_cliffs: cliff > 0.5 && alt > CONFIG.sea_level + 5.0,
+            near_cliffs: cliff > 0.2,
             tree_density,
             forest_kind: if temp > 0.0 {
                 if temp > CONFIG.desert_temp {
@@ -678,6 +718,8 @@ impl SimChunk {
             },
             spawn_rate: 1.0,
             location: None,
+
+            structures: Structures { town: None },
         }
     }
 

world/src/util/fast_noise.rs

@@ -0,0 +1,49 @@
+use super::{RandomField, Sampler};
+use std::f32;
+use vek::*;
+
+pub struct FastNoise {
+    noise: RandomField,
+}
+
+impl FastNoise {
+    pub const fn new(seed: u32) -> Self {
+        Self {
+            noise: RandomField::new(seed),
+        }
+    }
+
+    fn noise_at(&self, pos: Vec3<i32>) -> f32 {
+        (self.noise.get(pos) % 4096) as f32 / 4096.0
+    }
+}
+
+impl Sampler<'static> for FastNoise {
+    type Index = Vec3<f64>;
+    type Sample = f32;
+
+    fn get(&self, pos: Self::Index) -> Self::Sample {
+        let near_pos = pos.map(|e| e.floor() as i32);
+
+        let v000 = self.noise_at(near_pos + Vec3::new(0, 0, 0));
+        let v100 = self.noise_at(near_pos + Vec3::new(1, 0, 0));
+        let v010 = self.noise_at(near_pos + Vec3::new(0, 1, 0));
+        let v110 = self.noise_at(near_pos + Vec3::new(1, 1, 0));
+        let v001 = self.noise_at(near_pos + Vec3::new(0, 0, 1));
+        let v101 = self.noise_at(near_pos + Vec3::new(1, 0, 1));
+        let v011 = self.noise_at(near_pos + Vec3::new(0, 1, 1));
+        let v111 = self.noise_at(near_pos + Vec3::new(1, 1, 1));
+
+        let factor = pos.map(|e| 0.5 - (e.fract() as f32 * f32::consts::PI).cos() * 0.5);
+
+        let x00 = Lerp::lerp(v000, v100, factor.x);
+        let x10 = Lerp::lerp(v010, v110, factor.x);
+        let x01 = Lerp::lerp(v001, v101, factor.x);
+        let x11 = Lerp::lerp(v011, v111, factor.x);
+
+        let y0 = Lerp::lerp(x00, x10, factor.y);
+        let y1 = Lerp::lerp(x01, x11, factor.y);
+
+        Lerp::lerp(y0, y1, factor.z) * 2.0 - 1.0
+    }
+}

world/src/util/grid.rs

@@ -0,0 +1,74 @@
+use vek::*;
+
+pub struct Grid<T> {
+    cells: Vec<T>,
+    size: Vec2<i32>,
+}
+
+impl<T: Clone> Grid<T> {
+    pub fn new(default_cell: T, size: Vec2<i32>) -> Self {
+        Self {
+            cells: vec![default_cell; size.product() as usize],
+            size,
+        }
+    }
+
+    fn idx(&self, pos: Vec2<i32>) -> Option<usize> {
+        if pos.map2(self.size, |e, sz| e >= 0 && e < sz).reduce_and() {
+            Some((pos.y * self.size.x + pos.x) as usize)
+        } else {
+            None
+        }
+    }
+
+    pub fn size(&self) -> Vec2<i32> {
+        self.size
+    }
+
+    pub fn get(&self, pos: Vec2<i32>) -> Option<&T> {
+        self.cells.get(self.idx(pos)?)
+    }
+
+    pub fn get_mut(&mut self, pos: Vec2<i32>) -> Option<&mut T> {
+        let idx = self.idx(pos)?;
+        self.cells.get_mut(idx)
+    }
+
+    pub fn set(&mut self, pos: Vec2<i32>, cell: T) -> Option<()> {
+        let idx = self.idx(pos)?;
+        self.cells.get_mut(idx).map(|c| *c = cell)
+    }
+
+    pub fn iter(&self) -> impl Iterator<Item = (Vec2<i32>, &T)> + '_ {
+        let w = self.size.x;
+        self.cells
+            .iter()
+            .enumerate()
+            .map(move |(i, cell)| (Vec2::new(i as i32 % w, i as i32 / w), cell))
+    }
+
+    pub fn iter_mut(&mut self) -> impl Iterator<Item = (Vec2<i32>, &mut T)> + '_ {
+        let w = self.size.x;
+        self.cells
+            .iter_mut()
+            .enumerate()
+            .map(move |(i, cell)| (Vec2::new(i as i32 % w, i as i32 / w), cell))
+    }
+
+    pub fn iter_area(
+        &self,
+        pos: Vec2<i32>,
+        size: Vec2<i32>,
+    ) -> impl Iterator<Item = Option<(Vec2<i32>, &T)>> + '_ {
+        (0..size.x)
+            .map(move |x| {
+                (0..size.y).map(move |y| {
+                    Some((
+                        pos + Vec2::new(x, y),
+                        &self.cells[self.idx(pos + Vec2::new(x, y))?],
+                    ))
+                })
+            })
+            .flatten()
+    }
+}

world/src/util/mod.rs

@@ -1,3 +1,5 @@
+pub mod fast_noise;
+pub mod grid;
 pub mod hash_cache;
 pub mod random;
 pub mod sampler;
@@ -7,6 +9,8 @@ pub mod unit_chooser;
 
 // Reexports
 pub use self::{
+    fast_noise::FastNoise,
+    grid::Grid,
     hash_cache::HashCache,
     random::{RandomField, RandomPerm},
     sampler::{Sampler, SamplerMut},

world/src/util/random.rs

@@ -11,26 +11,26 @@ impl RandomField {
     }
 }
 
-impl Sampler for RandomField {
+impl Sampler<'static> for RandomField {
     type Index = Vec3<i32>;
     type Sample = u32;
 
     fn get(&self, pos: Self::Index) -> Self::Sample {
-        let pos = pos.map(|e| (e * 13 + (1 << 31)) as u32);
+        let pos = pos.map(|e| u32::from_le_bytes(e.to_le_bytes()));
 
         let mut a = self.seed;
         a = (a ^ 61) ^ (a >> 16);
-        a = a + (a << 3);
+        a = a.wrapping_add(a << 3);
         a = a ^ pos.x;
         a = a ^ (a >> 4);
-        a = a * 0x27d4eb2d;
+        a = a.wrapping_mul(0x27d4eb2d);
         a = a ^ (a >> 15);
         a = a ^ pos.y;
         a = (a ^ 61) ^ (a >> 16);
-        a = a + (a << 3);
+        a = a.wrapping_add(a << 3);
         a = a ^ (a >> 4);
         a = a ^ pos.z;
-        a = a * 0x27d4eb2d;
+        a = a.wrapping_mul(0x27d4eb2d);
         a = a ^ (a >> 15);
         a
     }
@@ -46,17 +46,19 @@ impl RandomPerm {
     }
 }
 
-impl Sampler for RandomPerm {
+impl Sampler<'static> for RandomPerm {
     type Index = u32;
     type Sample = u32;
 
     fn get(&self, perm: Self::Index) -> Self::Sample {
-        let mut a = perm;
-        a = (a ^ 61) ^ (a >> 16);
-        a = a + (a << 3);
-        a = a ^ (a >> 4);
-        a = a * 0x27d4eb2d;
-        a = a ^ (a >> 15);
-        a
+        let a = self
+            .seed
+            .wrapping_mul(3471)
+            .wrapping_add(perm)
+            .wrapping_add(0x3BE7172B)
+            .wrapping_mul(perm)
+            .wrapping_add(0x172A3BE1);
+        let b = a.wrapping_mul(a);
+        b ^ (a >> 17) ^ b >> 15
     }
 }

world/src/util/sampler.rs

@@ -1,13 +1,13 @@
-pub trait Sampler: Sized {
-    type Index;
-    type Sample;
+pub trait Sampler<'a>: Sized {
+    type Index: 'a;
+    type Sample: 'a;
 
     fn get(&self, index: Self::Index) -> Self::Sample;
 }
 
-pub trait SamplerMut: Sized {
-    type Index;
-    type Sample;
+pub trait SamplerMut<'a>: Sized {
+    type Index: 'a;
+    type Sample: 'a;
 
     fn get(&mut self, index: Self::Index) -> Self::Sample;
 }

world/src/util/structure.rs

@@ -21,7 +21,7 @@ impl StructureGen2d {
     }
 }
 
-impl Sampler for StructureGen2d {
+impl Sampler<'static> for StructureGen2d {
     type Index = Vec2<i32>;
     type Sample = [(Vec2<i32>, u32); 9];
 

world/src/util/unit_chooser.rs

@@ -24,7 +24,7 @@ impl UnitChooser {
     }
 }
 
-impl Sampler for UnitChooser {
+impl Sampler<'static> for UnitChooser {
     type Index = u32;
     type Sample = (Vec2<i32>, Vec2<i32>);