TL;DR they work exactly the same; the difference comes from trade-offs like performance, value range and (sometimes) syntax.
It's is possible to simulate floating- or fixed-point math, you just have to write all logic yourself (or use library). The only limits are your creativity and resulting performance overhead.
Fixed-point math may be considered a subset ...
A common misunderstanding about FixedUpdate is that it runs with a regular rhythm in real time / wall time. ie. that Unity is watching the clock like a hawk, and when the real-time moment for the next FixedUpdate comes around, it puts everything on hold and immediately runs FixedUpdate on that exact moment, then waits for the next moment again.
This is not ...
This is a bit of a Catch-22, unfortunately.
It's mainly the larger studios who need dedicated engine and graphics programmers, building out, porting, and optimizing custom engine features or rendering pipelines.
The ready availability of flexible, full-featured, off-the-shelf engines like Unreal and Unity means that many small studios are able to get the ...
I've been using FixedPoint (FxP) for last several years across multiple 8/16/32/64 bit platforms (mostly in Assembler).
The single most problematic issue with FxP is occasional overflow during multiplication. Very hard to reproduce and debug if it happens at 1 frame out of 1,000, especially in Assembler.
I would very strongly recommend doing initial ...
I multiply the velocity by -1 to the the opposite direction
That's your mistake. If you do that, you then have to check if you have gone into reverse.
Easier ways focus on scalar rather than vector arithmetic, as it's cheaper and easier to reason about.
Friction works as follows:
const FRICTION = 0.1;
let speed = velocityVector.magnitude();
Yes, you can use both at the same time. Though, you can only have 2D physics interactions with the 2D physics engine. The models are separate from the logic of the physics engines, so your objects can even have 3D models but 2D physics. Your raycasts can be separate from the physics engine too.
You can just turn the 2D rigidbodies on or off. That will ...