using System;
using StereoKit;

class OrbitalView {
	public static float strength = 0.5f;
	public static float distance = 0.25f;
	public static Matrix transform {
		get {
			Vec3 pos = Input.Head.position + (Input.Head.Forward * distance);

			Vec2 headDirection2D = Input.Head.Forward.XZ.Normalized;
			float angle = -Vec2.AngleBetween(prevDir, headDirection2D);
			Quat rot = prevRot * Quat.Slerp(Quat.Identity, Quat.FromAngles(Vec3.Up * angle), strength);

			prevDir = headDirection2D;
			prevRot = rot;

			return Matrix.TR(pos, rot);
		}
	}

	private static Vec2 prevDir = Vec3.Forward.XZ;
	private static Quat prevRot = Quat.Identity;
}