Extract movement into collidable::move.

engine/include/game/engine/entity.hpp

@@ -25,6 +25,7 @@ namespace engine {
     graphics::object const & render_info() const { return render_info_; }
 
   protected:
+    void move(math::vec2 const & delta);
     // A mix of position and graphics info
     graphics::object render_info_;
   };

engine/src/entity.cxx

@@ -27,6 +27,14 @@ collidable::collidable(graphics::object const & obj)
 collidable::collidable(Json::Value const & json, graphics::manager const & mgr)
     : identity<collidable>(next_id()), render_info_(to_object(json, mgr)) {}
 
+void collidable::move(math::vec2 const & delta) {
+  render_info_.location.origin += delta;
+  render_info_.points.ll += delta;
+  render_info_.points.lr += delta;
+  render_info_.points.ur += delta;
+  render_info_.points.ul += delta;
+}
+
 entity::entity(Json::Value const & json, graphics::manager const & mgr)
     : collidable(json, mgr), velocity(to_vec2(json["velocity"])),
       frame_texture_coords({make_vector(0.f, 0.f)}),
@@ -37,12 +45,7 @@ entity::entity(Json::Value const & json, graphics::manager const & mgr)
 
 void entity::update(float delta) {
   last_position = render_info_.location.origin;
-  auto delta_pos = velocity * delta;
-  render_info_.location.origin += delta_pos;
-  render_info_.points.ll += delta_pos;
-  render_info_.points.lr += delta_pos;
-  render_info_.points.ur += delta_pos;
-  render_info_.points.ul += delta_pos;
+  move(velocity * delta);
   velocity += acceleration * delta;
   //  render_info.angle += angular_velocity * delta;
 }