Enabling threading with RESOURCES_THREADING (Config.hpp) causes a serious CPU overhead.

The number of workers does not change anything : the CPU usage is the same with 1 or 32 workers.
This is confirmed as the CPU usage doesn't change when multiple empty tasks with long sleep commands are issued.

Strangely enough, there is a downpeak when changing from intro screen to menu screen, or from menu screen to game screen (when TransitionScreen is active?)

Following #2

• Add more assertions checks (pre/post conditions)
• Add more exceptions checks (runtime errors)
• Done Replace current Exception enum (Config.hpp) with something better (e.g. custom classes)

Although pause should be handled in main, it can be a screen overlapping the current one instead of the modal mechanism it is actually.

Require #3 Memory pools

Particle system allow to have cheap, but still good looking effects easily.

The use of sf::VertexArray is highly recommended to draw multiple sprites with a single texture, as it is much faster.

Reduce allocation times by using memory pools.

Quadtrees and Particles could profit a lot from theses pools, as they do frequent allocations/deallocations.

Entities would not benefit as much, because they can have varying sizes, and stay on the screen for a relatively long time

This problem is known in SFML, and seems to come from the resolution of the sleep function Windows use.

It causes random variations of the FPS count depending on the other running applications (try closing / opening your web browser and check the FPS counter).

Possible solutions :

• Use custom active sleep (with tinythread yield) for short times
• Find a way to fix it in SFML

VSync is also affecting the FPS counter...

asserts is not a good exception handling mechanism.
Some errors must be catched even in release mode.

• Create an exception type / class to handle critical errors
• Check every assert for it's validity
• Replace errors that must always be verified by exception throws
• Print errors on the screen nicely