feat(ai): add NavAgent ECS component

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/voltex_ai/src/lib.rs

@@ -1,7 +1,9 @@
+pub mod nav_agent;
 pub mod navmesh;
 pub mod pathfinding;
 pub mod steering;
 
+pub use nav_agent::NavAgent;
 pub use navmesh::{NavMesh, NavTriangle};
 pub use pathfinding::find_path;
 pub use steering::{SteeringAgent, seek, flee, arrive, wander, follow_path};

crates/voltex_ai/src/nav_agent.rs

@@ -0,0 +1,85 @@
+use voltex_math::Vec3;
+
+/// ECS component for AI pathfinding navigation.
+#[derive(Debug, Clone)]
+pub struct NavAgent {
+    pub target: Option<Vec3>,
+    pub speed: f32,
+    pub path: Vec<Vec3>,
+    pub current_waypoint: usize,
+    pub reached: bool,
+}
+
+impl NavAgent {
+    pub fn new(speed: f32) -> Self {
+        NavAgent {
+            target: None,
+            speed,
+            path: Vec::new(),
+            current_waypoint: 0,
+            reached: false,
+        }
+    }
+
+    pub fn set_target(&mut self, target: Vec3) {
+        self.target = Some(target);
+        self.path.clear();
+        self.current_waypoint = 0;
+        self.reached = false;
+    }
+
+    pub fn clear_target(&mut self) {
+        self.target = None;
+        self.path.clear();
+        self.current_waypoint = 0;
+        self.reached = false;
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_new_defaults() {
+        let agent = NavAgent::new(5.0);
+        assert!((agent.speed - 5.0).abs() < 1e-6);
+        assert!(agent.target.is_none());
+        assert!(agent.path.is_empty());
+        assert_eq!(agent.current_waypoint, 0);
+        assert!(!agent.reached);
+    }
+
+    #[test]
+    fn test_set_target() {
+        let mut agent = NavAgent::new(3.0);
+        agent.set_target(Vec3::new(10.0, 0.0, 5.0));
+        assert!(agent.target.is_some());
+        let t = agent.target.unwrap();
+        assert!((t.x - 10.0).abs() < 1e-6);
+        assert!(!agent.reached);
+    }
+
+    #[test]
+    fn test_set_target_clears_path() {
+        let mut agent = NavAgent::new(3.0);
+        agent.path = vec![Vec3::new(1.0, 0.0, 0.0), Vec3::new(2.0, 0.0, 0.0)];
+        agent.current_waypoint = 1;
+        agent.set_target(Vec3::new(5.0, 0.0, 5.0));
+        assert!(agent.path.is_empty());
+        assert_eq!(agent.current_waypoint, 0);
+    }
+
+    #[test]
+    fn test_clear_target() {
+        let mut agent = NavAgent::new(3.0);
+        agent.set_target(Vec3::new(10.0, 0.0, 5.0));
+        agent.path = vec![Vec3::new(1.0, 0.0, 0.0)];
+        agent.reached = true;
+        agent.clear_target();
+        assert!(agent.target.is_none());
+        assert!(agent.path.is_empty());
+        assert_eq!(agent.current_waypoint, 0);
+        assert!(!agent.reached);
+    }
+}