From 6a3723294ed8bb4f15c82081a81aeba3fa792795 Mon Sep 17 00:00:00 2001
From: Tipragot <contact@tipragot.fr>
Date: Mon, 12 Feb 2024 19:17:19 +0100
Subject: [PATCH] save

---
 crates/border-wars/src/generation.rs | 163 +++++++++++++++++++++++++++
 crates/border-wars/src/lib.rs        |   1 +
 2 files changed, 164 insertions(+)
 create mode 100644 crates/border-wars/src/generation.rs

diff --git a/crates/border-wars/src/generation.rs b/crates/border-wars/src/generation.rs
new file mode 100644
index 0000000..223bb13
--- /dev/null
+++ b/crates/border-wars/src/generation.rs
@@ -0,0 +1,163 @@
+//! TODO
+
+use std::collections::hash_map::Entry;
+use std::collections::{HashMap, HashSet, LinkedList};
+
+use bevy::prelude::*;
+
+/// TODO
+#[derive(Component)]
+pub struct Tile;
+
+pub trait TileDirection: Component {
+    type Inverse: TileDirection<Inverse = Self>;
+    fn new(entity: Entity) -> Self;
+}
+
+/// TODO
+#[derive(Component)]
+pub struct TopLeftTile(pub Entity);
+
+impl TileDirection for TopLeftTile {
+    type Inverse = BottomRightTile;
+
+    fn new(entity: Entity) -> Self {
+        Self(entity)
+    }
+}
+
+/// TODO
+#[derive(Component)]
+pub struct TopRightTile(pub Entity);
+
+impl TileDirection for TopRightTile {
+    type Inverse = BottomLeftTile;
+
+    fn new(entity: Entity) -> Self {
+        Self(entity)
+    }
+}
+
+/// TODO
+#[derive(Component)]
+pub struct LeftTile(pub Entity);
+
+impl TileDirection for LeftTile {
+    type Inverse = RightTile;
+
+    fn new(entity: Entity) -> Self {
+        Self(entity)
+    }
+}
+
+/// TODO
+#[derive(Component)]
+pub struct RightTile(pub Entity);
+
+impl TileDirection for RightTile {
+    type Inverse = LeftTile;
+
+    fn new(entity: Entity) -> Self {
+        Self(entity)
+    }
+}
+
+/// TODO
+#[derive(Component)]
+pub struct BottomLeftTile(pub Entity);
+
+impl TileDirection for BottomLeftTile {
+    type Inverse = TopRightTile;
+
+    fn new(entity: Entity) -> Self {
+        Self(entity)
+    }
+}
+
+/// TODO
+#[derive(Component)]
+pub struct BottomRightTile(pub Entity);
+
+impl TileDirection for BottomRightTile {
+    type Inverse = TopLeftTile;
+
+    fn new(entity: Entity) -> Self {
+        Self(entity)
+    }
+}
+
+/// TODO
+fn link_tiles<Direction: TileDirection>(commands: &mut Commands, from: Entity, to: Entity) {
+    commands.entity(from).insert(Direction::new(to));
+    commands.entity(to).insert(Direction::Inverse::new(from));
+}
+
+/// TODO
+fn generate_circle(commands: &mut Commands, radius: u32) {
+    let mut old_tiles = HashSet::new();
+    let mut tiles = HashMap::new();
+    tiles.insert((0, 0), commands.spawn(Tile).id());
+    let mut new_tiles = LinkedList::from([(0, 0)]);
+    let mut current = LinkedList::from([(0, 0)]);
+    for i in 0..radius {
+        for &(x, y) in current.iter() {
+            let AdjacentPositions {
+                top_left,
+                top_right,
+                left,
+                right,
+                bottom_left,
+                bottom_right,
+            } = get_adjacent_positions(x, y);
+
+            // Top left
+            if !old_tiles.contains(&top_left) {
+                let top_left_entity = *tiles
+                    .entry(top_left)
+                    .or_insert_with(|| commands.spawn(Tile).id());
+                link_tiles::<TopLeftTile>(commands, top_left_entity, tiles[&(x, y)]);
+            }
+
+            new_tiles.push_back(top_left);
+        }
+        for &(x, y) in current.iter() {
+            old_tiles.insert((x, y));
+        }
+        current.clear();
+        std::mem::swap(&mut new_tiles, &mut current);
+    }
+}
+
+/// TODO
+struct AdjacentPositions {
+    /// TODO
+    top_left: (i32, i32),
+
+    /// TODO
+    top_right: (i32, i32),
+
+    /// TODO
+    left: (i32, i32),
+
+    /// TODO
+    right: (i32, i32),
+
+    /// TODO
+    bottom_left: (i32, i32),
+
+    /// TODO
+    bottom_right: (i32, i32),
+}
+
+/// TODO
+const fn get_adjacent_positions(x: i32, y: i32) -> AdjacentPositions {
+    let offset: i32 = y % 2;
+    AdjacentPositions {
+        left: (x - 1, y),
+        right: (x + 1, y),
+        top_left: (x - offset, y + 1),
+        top_right: (x - offset + 1, y + 1),
+        bottom_left: (x - offset, y - 1),
+        bottom_right: (x - offset + 1, y - 1),
+    }
+}
diff --git a/crates/border-wars/src/lib.rs b/crates/border-wars/src/lib.rs
index c85940e..8f91785 100644
--- a/crates/border-wars/src/lib.rs
+++ b/crates/border-wars/src/lib.rs
@@ -2,6 +2,7 @@
 
 use bevy::prelude::*;
 
+pub mod generation;
 pub mod scenes;
 
 /// The current scene of the game.