From a07ba21a5c34cbd817555e9146171f415494b58d Mon Sep 17 00:00:00 2001
From: AmadeusWM <63149896+AmadeusWM@users.noreply.github.com>
Date: Sun, 6 Apr 2025 18:45:43 +0200
Subject: [PATCH] better world generation

---
 src/level_instantiation/mod.rs | 70 ++++++++++++++++++++++++++--------
 1 file changed, 55 insertions(+), 15 deletions(-)

diff --git a/src/level_instantiation/mod.rs b/src/level_instantiation/mod.rs
index 043fc81..55d2961 100644
--- a/src/level_instantiation/mod.rs
+++ b/src/level_instantiation/mod.rs
@@ -12,6 +12,8 @@ pub fn map_plugin(app: &mut App) {
 
 fn spawn_level(
     mut commands: Commands,
+    mut meshes: ResMut<Assets<Mesh>>,
+    mut materials: ResMut<Assets<StandardMaterial>>,
     models: Res<Assets<Gltf>>,
     gltf_assets: Res<GltfAssets>
 ) {
@@ -74,7 +76,7 @@ fn spawn_level(
     //     Transform::from_xyz(-500.0, 3.0, -500.0),
     // ));
     // let map = GameMap::test();
-    let map = GameMap::new(100);
+    let map = GameMap::new(10);
     map.print_map();
 
     for ((x, z), node) in map.nodes.into_iter() {
@@ -203,6 +205,14 @@ fn spawn_level(
             });
         }
     }
+    let (x,z) = map.end_node;
+    commands.spawn((
+        Mesh3d(meshes.add(Cuboid::new(3.0, 3.0, 3.0))),
+        MeshMaterial3d(materials.add(Color::srgb_u8(255, 0, 0))),
+        Transform::from_xyz(2.0*x as f32, 0.5, -2.0*z as f32),
+        RigidBody::Fixed,
+        Collider::cuboid(0.5, 0.5, 0.5),
+    ));
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
@@ -218,7 +228,6 @@ struct MapNode {
     south: Side,
     east: Side,
     west: Side,
-    collapsed: bool,
 }
 
 impl MapNode {
@@ -228,18 +237,18 @@ impl MapNode {
             south: Side::Empty,
             east: Side::Empty,
             west: Side::Empty,
-            collapsed: false,
         }
     }
 }
 
 struct GameMap {
     nodes: HashMap<(i32, i32), MapNode>,
-    max_nodes: i32
+    end_node: (i32, i32),
+    grid_size: i32
 }
 
 impl GameMap {
-    fn new(max_nodes: i32) -> Self {
+    fn new(grid_size: i32) -> Self {
         let mut nodes = HashMap::new();
         let mut start_node = MapNode::new();
         start_node.north = Side::Connection;
@@ -247,7 +256,7 @@ impl GameMap {
         start_node.east = Side::Connection;
         start_node.west = Side::Connection;
         nodes.insert((0, 0), start_node);
-        let mut m = GameMap { nodes, max_nodes };
+        let mut m = GameMap { nodes, grid_size, end_node: (0, 0) };
         m.generate_map();
         m
     }
@@ -305,7 +314,11 @@ impl GameMap {
         wall_node5.south = Side::Connection;
         nodes.insert((3, 2), wall_node5);
 
-        GameMap { nodes, max_nodes: 7 }
+        GameMap {
+            nodes,
+            grid_size: 7,
+            end_node: (0, 0)
+        }
     }
 
     fn generate_map(&mut self) {
@@ -315,17 +328,38 @@ impl GameMap {
         // self.create_node(&(-1, 0)); // West
     }
 
-    fn choose_side(&self) -> Side {
-        if self.nodes.len() > self.max_nodes as usize {
+    fn choose_side(&self, pos: (i32, i32)) -> Side {
+        if pos.0 > self.grid_size || pos.1 > self.grid_size || pos.0 < 0 || pos.1 < 0 {
             Side::Closed
         } else {
             if rand::rng().random_bool(0.5) { Side::Connection } else { Side::Closed }
         }
     }
 
+    fn ensure_connection(&self, node: &mut MapNode) {
+        let am_connections = (node.north == Side::Connection) as u8 +
+            (node.south == Side::Connection) as u8 +
+            (node.east == Side::Connection) as u8 +
+            (node.west == Side::Connection) as u8;
+
+        if am_connections <= 2 {
+            if node.north != Side::Connection {
+                node.north = Side::Connection
+            }
+            else if node.south != Side::Connection {
+                node.south = Side::Connection
+            }
+            else if node.east != Side::Connection {
+                node.east = Side::Connection
+            }
+            else if node.west != Side::Connection {
+                node.west = Side::Connection
+            }
+        }
+    }
+
     fn create_node(&mut self, idx: &(i32, i32)) {
         let mut nodes_to_process = vec![*idx];
-        let mut nodes_created = 0;
 
         while let Some(current_idx) = nodes_to_process.pop() {
             if self.nodes.contains_key(&current_idx) {
@@ -335,16 +369,23 @@ impl GameMap {
             let (x, y) = current_idx;
             let mut new_node = MapNode::new();
 
+            if x >= self.end_node.0 && y >= self.end_node.1 {
+                self.end_node = (x, y);
+            }
+
             let north = self.nodes.get(&(x, y + 1));
             let south = self.nodes.get(&(x, y - 1));
             let east = self.nodes.get(&(x + 1, y));
             let west = self.nodes.get(&(x - 1, y));
 
-            new_node.north = north.map_or_else(|| self.choose_side(), |n| n.south);
-            new_node.south = south.map_or_else(|| self.choose_side(), |s| s.north);
-            new_node.east = east.map_or_else(|| self.choose_side(), |e| e.west);
-            new_node.west = west.map_or_else(|| self.choose_side(), |w| w.east);
+            new_node.north = north.map_or_else(|| self.choose_side(current_idx), |n| n.south);
+            new_node.south = south.map_or_else(|| self.choose_side(current_idx), |s| s.north);
+            new_node.east = east.map_or_else(|| self.choose_side(current_idx), |e| e.west);
+            new_node.west = west.map_or_else(|| self.choose_side(current_idx), |w| w.east);
 
+            if !(current_idx.0 > self.grid_size || current_idx.1 > self.grid_size || current_idx.0 < 0 || current_idx.1 < 0) {
+                self.ensure_connection(&mut new_node);
+            }
             if new_node.north == Side::Connection && !self.nodes.contains_key(&(x, y + 1)) {
                 nodes_to_process.push((x, y + 1));
             }
@@ -359,7 +400,6 @@ impl GameMap {
             }
 
             self.nodes.insert(current_idx, new_node);
-            nodes_created += 1;
         }
     }