diff -r 6e22f4390b7e -r c5684cc62de8 rust/landgen/src/wavefront_collapse.rs
--- a/rust/landgen/src/wavefront_collapse.rs	Mon Jan 30 15:50:14 2023 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,150 +0,0 @@
-use integral_geometry::Size;
-use land2d::Land2D;
-use std::collections::HashMap;
-
-#[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
-enum Tile {
-    Empty,
-    Outside,
-    Numbered(u32),
-}
-
-impl Tile {
-    fn is(&self, i: u32) -> bool {
-        *self == Tile::Numbered(i)
-    }
-
-    fn is_empty(&self) -> bool {
-        match self {
-            Tile::Empty => true,
-            Tile::Outside => true,
-            _ => false,
-        }
-    }
-
-    fn is_empty_or(&self, i: u32) -> bool {
-        match self {
-            Tile::Numbered(n) => *n == i,
-            Tile::Empty => true,
-            _ => false,
-        }
-    }
-
-    fn is_void_or(&self, i: u32) -> bool {
-        match self {
-            Tile::Numbered(n) => *n == i,
-            _ => true,
-        }
-    }
-}
-
-impl Default for Tile {
-    fn default() -> Self {
-        Tile::Outside
-    }
-}
-
-struct CollapseRule {
-    to_tile: Tile,
-    condition: fn([Tile; 4]) -> bool,
-}
-
-#[derive(Default)]
-struct WavefrontCollapse {
-    rules: HashMap<Tile, Vec<CollapseRule>>,
-}
-
-impl WavefrontCollapse {
-    pub fn generate_map<I: Iterator<Item = u32>, F: FnOnce(&mut Land2D<Tile>)>(
-        &mut self,
-        map_size: &Size,
-        seed_fn: F,
-        random_numbers: &mut I,
-    ) -> Land2D<Tile> {
-        let mut land = Land2D::new(map_size, Tile::Empty);
-
-        seed_fn(&mut land);
-
-        while self.collapse_step(&mut land, random_numbers) {}
-
-        land
-    }
-
-    fn add_rule(&mut self, from_tile: Tile, to_tile: Tile, condition: fn([Tile; 4]) -> bool) {
-        let rule = CollapseRule { to_tile, condition };
-        self.rules
-            .entry(from_tile)
-            .or_insert_with(Vec::new)
-            .push(rule);
-    }
-
-    fn collapse_step<I: Iterator<Item = u32>>(
-        &self,
-        land: &mut Land2D<Tile>,
-        random_numbers: &mut I,
-    ) -> bool {
-        let mut collapse_occurred = false;
-        for x in 0..land.width() {
-            for y in 0..land.height() {
-                let current_tile = land.map(y as i32, x as i32, |p| *p);
-
-                if let Some(rules) = self.rules.get(&current_tile) {
-                    for rule in rules
-                        .iter()
-                        .cycle()
-                        .skip(
-                            random_numbers.next().unwrap_or_default() as usize % (rules.len() + 1),
-                        )
-                        .take(rules.len())
-                    {
-                        let neighbors = self.get_neighbors(&land, x, y);
-                        let have_neighbors = neighbors.iter().any(|t| !t.is_empty());
-                        if have_neighbors && (rule.condition)(neighbors) {
-                            land.map(y as i32, x as i32, |p| *p = rule.to_tile);
-                            collapse_occurred = true;
-                            break;
-                        }
-                    }
-                }
-            }
-        }
-
-        collapse_occurred
-    }
-
-    fn get_neighbors(&self, land: &Land2D<Tile>, x: usize, y: usize) -> [Tile; 4] {
-        [
-            land.get(y as i32, x as i32 + 1),
-            land.get(y as i32 + 1, x as i32),
-            land.get(y as i32, x as i32 - 1),
-            land.get(y as i32 - 1, x as i32),
-        ]
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::{CollapseRule, Tile, WavefrontCollapse};
-    use integral_geometry::Size;
-    use land2d::Land2D;
-    use std::collections::HashMap;
-
-    #[test]
-    fn test_wavefront_collapse() {
-        let size = Size::new(4, 4);
-        let mut rnd = [0u32; 64].into_iter();
-        let mut wfc = WavefrontCollapse::default();
-
-        let empty_land = Land2D::new(&size, Tile::Empty);
-        let no_rules_land = wfc.generate_map(&size, |l| {}, &mut rnd);
-
-        assert_eq!(empty_land.raw_pixels(), no_rules_land.raw_pixels());
-
-        wfc.add_rule(Tile::Empty, Tile::Numbered(0), |neighbors| {
-            neighbors.iter().filter(|&n| *n == Tile::Empty).count() >= 2
-        });
-        let ruled_map = wfc.generate_map(&size, |l| {}, &mut rnd);
-
-        assert_eq!(ruled_map.raw_pixels(), empty_land.raw_pixels());
-    }
-}