Tween rotation in 2D physics

[hydroper]

Hi, I'm trying to achieve this movement mechanism (similiar to SharkBite Bay Adventure):

• Demo on itch.io

This demo works, except there is no scrolling (Camera2D).

The issue of adding a Camera2D to that car is that I'm assigning rotation_degrees manually and a bug happens such that I'm unable to move the car. While this seems like a bug, since the game basically works as you see above, maybe it'd make sense to add a new property that is more useful than lock_rotation.

Considerations:

• CharacterBody2D: I've used CharacterBody2D instead of RigidBody2D. I've got 3 problems with it:
  • Can't apply force; I've have to change the speed manually.
  • If the car hits e.g. a wall and its speed is too high, it gets stuck in the wall unless I reset the speed in that direction by manually checking collisions. This is very ad-hoc.
  • I've to apply friction manually. By default the car won't be able to slide on walls.
• apply_torque: I don't want a torque; the game's movement system is similiar to SharkBite Bay, not like other common 2D top-down car games. For example:
  • If the player presses the down arrow, the car must tween its rotation to look at the bottom.
  • If the player presses the left arrow, the car must tween its rotation to look at the left.
  • If the player presses the up and left arrows, the car must tween to look at the left-top.
• state.angular_velocity in _integrate_forces: it looks like changing the car's rotation in _integrate_forces with state.angular_velocity instead of setting rotation_degrees manually doesn't break the game, but then it's not possible to tween properly, because:
  • My tweener isn't just incrementing; it may also finish the tween by detecting if the current rotation is nearly the target rotation and then setting the current rotation to the target rotation.

Also, unrelated to the problem, but I had to implement my own tweener (which is simple) because Godot's built-in Tween:

• Requires a duration. There's no duration in my case; I do want a linear transition, but want a constant increment on the rotation.
• Goes either clockwise or counterclockwise wrongly sometimes (e.g. I want to go to target angle through the fatest route: clockwise or counterclockwise).

I think there should be a built-in way to constantly tween the rotation in physics without having to tweak the angular_velocity. Any idea?

Here's the source:

• https://github.com/hydroper/carknockonline

[hydroper]

@AThousandShips I got a very good result by using angular_velocity as suggested by @AThousandShips. When the entity's angle is almost near the final angle, I assign angular_velocity = 1 or -1; if it's far, it's angular_velocity = scale * (1 or -1). The final angle is always an integer between 0-360; I also convert the current entity's angle to be an integer in this same range. It worked very well!

https://github.com/hydroper/carknockonline/blob/master/src/util/constant_physics_rotation_tween.gd

I updated the demo so you can see it working:

• https://hydroper.itch.io/carknockonlinetest