Sorted out the animation vs. easing contradiction I believe. Now there's a separate easing_duration that's calculated from the total duration of all frames. Then a easing_position determines where in the total the animation is, which is fed to the asing functions as a ration of easing_position / easing_duration.

camera.cpp

@@ -98,8 +98,6 @@ namespace cinematic {
   }
 
   void Camera::update() {
-    // REFACTOR: there's no connection between anim.commit() and anim.update()
-    auto [ticks, alpha] = anim.commit();
     if(anim.playing) anim.update();
   }