namespace blank {
 
+class World;
+
 class Chaser
 : public Controller {
 
 public:
-       Chaser(Entity &ctrl, Entity &tgt) noexcept;
+       Chaser(World &, Entity &ctrl, Entity &tgt) noexcept;
        ~Chaser();
 
        Entity &Target() noexcept { return tgt; }
        void Update(int dt) override;
 
 private:
+       World &world;
        Entity &tgt;
-       float speed;
+       float chase_speed;
+       float flee_speed;
        float stop_dist;
        float flee_dist;
 
 
 #include "Controller.hpp"
 #include "RandomWalk.hpp"
 
+#include "../model/geometry.hpp"
 #include "../world/Entity.hpp"
+#include "../world/World.hpp"
 
 #include <glm/glm.hpp>
 
 
 namespace blank {
 
-Chaser::Chaser(Entity &ctrl, Entity &tgt) noexcept
+Chaser::Chaser(World &world, Entity &ctrl, Entity &tgt) noexcept
 : Controller(ctrl)
+, world(world)
 , tgt(tgt)
-, speed(0.002f)
-, stop_dist(5 * 5)
-, flee_dist(3 * 3) {
+, chase_speed(0.002f)
+, flee_speed(-0.005f)
+, stop_dist(10)
+, flee_dist(5) {
 
 }
 
 
 void Chaser::Update(int dt) {
        glm::vec3 diff(Target().AbsoluteDifference(Controlled()));
-       float dist = dot (diff, diff);
-       // TODO: line of sight test
-       if (dist > stop_dist) {
-               Controlled().Velocity(normalize(diff) * speed);
+       float dist = length(diff);
+       glm::vec3 norm_diff(diff / dist);
+
+       bool line_of_sight = true;
+       // FIXME: this only works if target is in the reference chunk (which is true for the player)
+       Ray aim{Target().Position() - diff, norm_diff};
+       Chunk *chunk;
+       int blkid;
+       float distance;
+       glm::vec3 normal;
+       if (world.Intersection(aim, glm::mat4(1.0f), chunk, blkid, distance, normal)) {
+               line_of_sight = distance > dist;
+       }
+
+       if (!line_of_sight) {
+               Controlled().Velocity(glm::vec3(0.0f));
+       } else if (dist > stop_dist) {
+               Controlled().Velocity(norm_diff * chase_speed);
        } else if (dist < flee_dist) {
-               Controlled().Velocity(normalize(diff) * -speed);
+               Controlled().Velocity(norm_diff * flee_speed);
        } else {
                Controlled().Velocity(glm::vec3(0.0f));
        }