fixed update for regen and expand

src/map.rs

@@ -26,21 +26,27 @@ use picking::*;
 pub struct Plugin;
 impl bevy::prelude::Plugin for Plugin {
     fn build(&self, app: &mut App) {
-        app.add_systems(Startup, setup)
+        app.add_plugins(cells::Plugin)
+            .add_systems(Startup, setup)
             .add_systems(PreUpdate, picking_backend.in_set(PickSet::Backend))
-            .add_systems(Update, (update_map_mesh, cells_regeneration, expand))
+            .add_systems(Update, update_map_mesh)
             .insert_resource(ClearColor(Color::srgb(0., 0., 1.)))
-            .insert_resource(Seed(thread_rng().gen()))
-            .add_plugins(MaterialPlugin::<CellMaterial>::default());
+            .insert_resource(Seed(thread_rng().gen()));
     }
 }
 
-pub const HEIGHT: f32 = 16.;
-pub const WIDTH: f32 = 16.;
+/// Determined empirically
+pub const AVERAGE_NEIGHBORS_NUMBER: f64 = 6.;
+
+pub const HEIGHT: f64 = 16.;
+pub const WIDTH: f64 = 16.;
 pub const REAL_HEIGHT: f32 = 8000.;
 pub const REAL_WIDTH: f32 = 8000.;
-pub const CELL_AREA: f32 = REAL_HEIGHT * REAL_WIDTH / SIZE as f32;
-pub const SIZE: usize = 100_000;
+pub const CELL_AREA: f32 = REAL_HEIGHT * REAL_WIDTH / CELLS as f32;
+pub const CELLS_TARGET_NUMBER: usize = 100_000;
+pub const CHUNKS_RESOLUTION: usize = 2;
+pub const CELLS_PER_CHUNK: usize = CELLS_TARGET_NUMBER / CHUNKS_RESOLUTION.pow(2);
+pub const CELLS: usize = CELLS_PER_CHUNK * CHUNKS_RESOLUTION.pow(2);
 
 #[derive(Resource)]
 struct Seed(u32);
@@ -68,24 +74,41 @@ fn setup(
     seed: Res<Seed>,
 ) {
     let mut rng = rand::rngs::SmallRng::seed_from_u64(seed.0 as u64);
-    let mut sites = Vec::with_capacity(SIZE);
-    for _ in 0..SIZE {
-        sites.push(Point {
-            x: rng.gen_range(-WIDTH / 2.0..WIDTH / 2.0) as f64,
-            y: rng.gen_range(-HEIGHT / 2.0..HEIGHT / 2.0) as f64,
-        })
+    let mut sites = Vec::with_capacity(CELLS);
+    for chunk_x in 0..CHUNKS_RESOLUTION {
+        let min_x = WIDTH / 2. * ((2. * (chunk_x as f64) / (CHUNKS_RESOLUTION as f64)) - 1.);
+        let max_x = min_x + (WIDTH as f64 / CHUNKS_RESOLUTION as f64);
+        for chunk_y in 0..CHUNKS_RESOLUTION {
+            let min_y = HEIGHT / 2. * ((2. * (chunk_y as f64) / (CHUNKS_RESOLUTION as f64)) - 1.);
+            let max_y = min_y + (HEIGHT as f64 / CHUNKS_RESOLUTION as f64);
+            println!(
+                "[{},{}] x:[{}, {}], y:[{}, {}]",
+                chunk_x, chunk_y, min_x, max_x, min_y, max_y
+            );
+            for _ in 0..CELLS_PER_CHUNK {
+                sites.push(Point {
+                    x: rng.gen_range(min_x..max_x),
+                    y: rng.gen_range(min_y..max_y),
+                });
+            }
+        }
     }
+    // dbg!(sites.len());
+
     let voronoi = VoronoiBuilder::default()
         .set_sites(sites)
-        .set_bounding_box(BoundingBox::new_centered(WIDTH as f64, HEIGHT as f64))
+        .set_bounding_box(BoundingBox::new_centered(WIDTH, HEIGHT))
         .set_lloyd_relaxation_iterations(3)
         .build()
         .unwrap();
-    let mut cells = Vec::with_capacity(SIZE);
+
+    let mut cells = Vec::with_capacity(CELLS);
     let z_noise = Fbm::<Perlin>::new(seed.0);
     let moisture_noise = Fbm::<Perlin>::new(seed.0 + 1).set_frequency(2.);
-    for i in 0..SIZE {
+    let mut res = 0;
+    for i in 0..CELLS {
         let c = voronoi.cell(i);
+        res += c.iter_neighbors().count();
         let site = c.site_position();
         let z = get_altitude(&z_noise, &[site.x as f32, site.y as f32]);
         let _m = (
@@ -108,6 +131,7 @@ fn setup(
             vertices: vec![],
         });
     }
+    dbg!(res as f64 / CELLS as f64);
 
     let mut poss = Vec::new();
     let mut indices = Vec::new();
@@ -181,27 +205,27 @@ fn setup(
         MapMeshColors(colors),
         MeshNeedsUpdate(true),
         MapMarker,
-    ))
-    .with_children(|parent| {
-        for cell in cells {
-            let kind = cell.kind;
-            let mut cmd = parent.spawn(cell);
-            match kind {
-                CellKind::Grass | CellKind::Forest => {
-                    cmd.insert((
-                        Wealth(0),
-                        Regeneration {
-                            last_update: Duration::ZERO,
-                            full_growth_duration: kind.regen_full_growth_duration(),
-                        },
-                    ));
-                }
-                _ => {}
+    ));
+
+    for cell in cells {
+        let kind = cell.kind;
+        let mut cmd = cmds.spawn(cell);
+        match kind {
+            CellKind::Grass | CellKind::Forest => {
+                cmd.insert((
+                    Wealth(0),
+                    Regeneration {
+                        last_update: Duration::ZERO,
+                        full_growth_duration: kind.regen_full_growth_duration(),
+                    },
+                ));
             }
-            cmd.observe(self::cells::on_click);
-            cells_entities.push(cmd.id());
+            _ => {}
         }
-    });
+        cmd.observe(self::cells::on_click);
+        cells_entities.push(cmd.id());
+    }
+
     cmds.insert_resource(Voronoi(voronoi));
     cmds.insert_resource(CellsEntities(cells_entities));
 }
@@ -219,10 +243,12 @@ fn update_map_mesh(
             for (cell, wealth) in cells.iter() {
                 // let col: [f32; 4] = [rng.gen(), rng.gen(), rng.gen(), 1.];
                 let col = cell.color(wealth.map(|w| w.0).unwrap_or_default());
-                for id in cell.vertices.iter() {
-                    modified = modified || cols.0[*id] != col;
-                    cols.0[*id] = col.clone();
-                }
+                modified = modified || cols.0[cell.voronoi_id] != col;
+                cols.0[cell.voronoi_id] = col;
+                // for id in cell.vertices.iter() {
+                //     modified = modified || cols.0[*id] != col;
+                //     cols.0[*id] = col.clone();
+                // }
             }
             if modified {
                 mesh.insert_attribute(Mesh::ATTRIBUTE_COLOR, cols.0.clone());

src/map/cells.rs

@@ -1,13 +1,31 @@
 use std::time::Duration;
 
-use bevy::prelude::*;
+use bevy::{prelude::*, time::common_conditions::on_timer};
 use rand::{seq::IteratorRandom, thread_rng, Rng};
 
 use crate::{time::GameTime, ui::CurrentAction};
 
-use super::{animals::Animal, AnimalKind, CellsEntities, MapMarker, MeshNeedsUpdate, Voronoi};
+use super::{
+    animals::Animal, AnimalKind, CellsEntities, MapMarker, MeshNeedsUpdate, Voronoi,
+    AVERAGE_NEIGHBORS_NUMBER, CELL_AREA,
+};
 
 pub mod material;
+use material::CellMaterial;
+
+pub struct Plugin;
+impl bevy::prelude::Plugin for Plugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(
+            FixedUpdate,
+            (
+                cells_regeneration.run_if(on_timer(Duration::from_secs(1))),
+                expand.run_if(on_timer(Duration::from_secs(1))),
+            ),
+        )
+        .add_plugins(MaterialPlugin::<CellMaterial>::default());
+    }
+}
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum CellKind {
@@ -79,6 +97,7 @@ pub struct Regeneration {
     pub full_growth_duration: Duration,
 }
 
+const STEP: u8 = u8::MAX / 4;
 pub fn cells_regeneration(
     mut cells: Query<(&mut Regeneration, &mut Wealth)>,
     mut map_needs_update: Query<&mut MeshNeedsUpdate, With<MapMarker>>,
@@ -86,10 +105,15 @@ pub fn cells_regeneration(
 ) {
     let mut map_needs_update = map_needs_update.single_mut();
     for (mut regen, mut wealth) in cells.iter_mut() {
-        if gt.current - regen.last_update > regen.full_growth_duration / u8::MAX as u32 {
-            regen.last_update = gt.current;
+        while gt.current - regen.last_update > regen.full_growth_duration / u8::MAX as u32 {
+            regen.last_update = gt
+                .current
+                .min(regen.last_update + (regen.full_growth_duration / u8::MAX as u32));
             wealth.0 = wealth.0.saturating_add(1);
-            map_needs_update.0 = true;
+            // Not update map each time for optimization
+            if wealth.0 % STEP == 0 {
+                map_needs_update.0 = true;
+            }
         }
     }
 }
@@ -113,28 +137,43 @@ pub fn expand(
                 wealth.unwrap().0 as f64 / 255.
             };
             if random.gen_bool(
-                (t.elapsed_secs_f64() * (gt.speed as f64) * wealth / (60. * 60. * 24. * 30.))
-                    .min(1.),
+                dbg!(
+                    t.elapsed_secs_f64() * (gt.speed as f64) * wealth * 1e-7
+                        / (CELL_AREA as f64).sqrt()
+                )
+                .min(1.),
             ) {
-                // Let say that grass takes 1 months to expand
+                // "Grass can expand into adjacent dirt at a rate of 2.5 to 7.5 cm (1 to 3 inches) per month.", DeepSeek
+                // With some (way too complicated and probably false) computation, we get for a good grass an extension rate of (1e-7 / sqrt(cell_area)) cells per seconds
                 let target = voronoi
                     .0
                     .cell(cell.voronoi_id)
                     .iter_neighbors()
                     .choose(&mut random)
                     .unwrap();
-                changes.push((target, CellKind::Grass));
+                changes.extend(
+                    voronoi
+                        .0
+                        .cell(cell.voronoi_id)
+                        .iter_neighbors()
+                        .map(|t| (t, CellKind::Grass)),
+                );
             }
         }
         if cell.kind == CellKind::Forest {
             if random.gen_bool(
-                (t.elapsed_secs_f64()
-                    * (gt.speed as f64)
-                    * (wealth.unwrap().0 as f64 / 255.).sqrt()
-                    / (60. * 60. * 24. * 365. * 5.))
-                    .min(1.),
+                dbg!(
+                    t.elapsed_secs_f64()
+                        * (gt.speed as f64)
+                        * (wealth.unwrap().0 as f64 / 255.).sqrt()
+                        * 5.6e-7
+                        / (CELL_AREA as f64).sqrt()
+                        * AVERAGE_NEIGHBORS_NUMBER
+                )
+                .min(1.),
             ) {
-                // Let say that forest takes 5 years to expand
+                // "Forests can expand at a rate of 1 to 10 meters per year", DeepSeek
+                // Same computations as above : (5.6e-7 / sqrt(cell_area)) cells per seconds
                 let target = voronoi
                     .0
                     .cell(cell.voronoi_id)