92 lines
3.2 KiB
C#
92 lines
3.2 KiB
C#
using System;
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using System.Collections.Generic;
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using UnityEngine;
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namespace Mirror.Examples.BilliardsPredicted
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{
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// example input for this exact demo.
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// not general purpose yet.
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public struct PlayerInput
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{
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public double timestamp;
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public Vector3 force;
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public PlayerInput(double timestamp, Vector3 force)
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{
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this.timestamp = timestamp;
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this.force = force;
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}
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}
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public class PlayerPredicted : NetworkBehaviour
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{
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// white ball component
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WhiteBallPredicted whiteBall;
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void Awake()
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{
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// find the white ball once
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#if UNITY_2022_2_OR_NEWER
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whiteBall = FindAnyObjectByType<WhiteBallPredicted>();
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#else
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// Deprecated in Unity 2023.1
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whiteBall = FindObjectOfType<WhiteBallPredicted>();
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#endif
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}
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// apply force to white ball.
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// common function to ensure we apply it the same way on server & client!
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void ApplyForceToWhite(Vector3 force)
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{
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// https://docs.unity3d.com/2021.3/Documentation/ScriptReference/Rigidbody.AddForce.html
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// this is buffered until the next FixedUpdate.
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// get the white ball's Rigidbody.
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// prediction sometimes moves this out of the object for a while,
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// so we need to grab it this way:
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Rigidbody rb = whiteBall.GetComponent<PredictedRigidbody>().predictedRigidbody;
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// AddForce has different force modes, see this excellent diagram:
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// https://www.reddit.com/r/Unity3D/comments/psukm1/know_the_difference_between_forcemodes_a_little/
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// for prediction it's extremely important(!) to apply the correct mode:
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// 'Force' makes server & client drift significantly here
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// 'Impulse' is correct usage with significantly less drift
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rb.AddForce(force, ForceMode.Impulse);
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}
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// called when the local player dragged the white ball.
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// we reuse the white ball's OnMouseDrag and forward the event to here.
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public void OnDraggedBall(Vector3 force)
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{
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// apply force locally immediately
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ApplyForceToWhite(force);
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// apply on server as well.
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// not necessary in host mode, otherwise we would apply it twice.
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if (!isServer) CmdApplyForce(force);
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}
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// while prediction is applied on clients immediately,
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// we still want to validate every input on the server and reject it if necessary.
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// this way we can latency free yet cheat safe movement.
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// this should include a certain tolerance so players aren't hard corrected
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// for their local movement all the time.
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// TODO this should be on some kind of base class for reuse, but perhaps independent of parameters?
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bool IsValidMove(Vector3 force) => true;
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// TODO send over unreliable with ack, notify, etc. later
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[Command]
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void CmdApplyForce(Vector3 force)
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{
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if (!IsValidMove(force))
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{
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Debug.Log($"Server rejected move: {force}");
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return;
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}
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// apply force
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ApplyForceToWhite(force);
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}
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}
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}
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