ProjectSquareBall/Assets/Scripts/ProtoTyping/BallPathTest.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class BallPathTest : MonoBehaviour
{
    public AudioSource audioToSync;
    public List<float> allHits = new List<float>();
    public LineRenderer line;
    public Transform mover;
    public float horizontalSpeed = 1f;
    public float gravity = -9f;
    public float gravityWhenUpwardMult = 1f;
    public float maxFallSpeed = 10;
    public AnimationCurve bouncingEfficiencyGraph = new AnimationCurve();
    // public float bouncingEfficiency =0.4f;
    public float changeDirCloseThresh = 0.1f;
    public Vector2 velocity;
    public bool simulate = false;

    public GameObject bouncerPrefab;
    public Transform bouncerParent;

    void OnValidate()
    {
        if (simulate)
        {
            Simulate();
            simulate = false;
        }
    }
    float timer = 0;
    public List<float> hitsCache = new List<float>();
    List<Vector3> pointsHistory = new List<Vector3>();
    List<BounceData> hitPointsHistory = new List<BounceData>();
    

    void Start()
    {
        Reset(Time.time);
    }

    void Reset(float time){
        velocity = new Vector2(horizontalSpeed, 0);
        mover.transform.position = Vector2.zero;
        hitsCache = new List<float>();
        hitsCache.AddRange(allHits);
        pointsHistory= new List<Vector3>();
        hitPointsHistory= new List<BounceData>();
        prevTime=time;
        timer =0;
    }

    // Update is called once per frame
    void Update()
    {
        ManualUpdate(Time.time);
    }

    float prevTime;
    bool ManualUpdate(float time){
        float dt = time - prevTime;
        prevTime = time;
        timer += dt;

        audioToSync.time = time;

        if(hitsCache.Count <= 1){return true;}

        velocity += new Vector2(0, gravity*dt * (velocity.y > 0 ? gravityWhenUpwardMult : 1));

        if (timer > hitsCache[0])
        {
            float timeToNextHit = hitsCache[1]-hitsCache[0];//(hitsCache.Count >1)?1:0
            Debug.Log($"hit: {timeToNextHit}, velocity : {velocity}");
            BounceData bounceData = new BounceData();
            bounceData.point = mover.position;
            bounceData.prevVelocity = velocity;
            //Bounce
            hitsCache.RemoveAt(0);
            bool changeDir= timeToNextHit < changeDirCloseThresh;
            float bouncingEfficiency = bouncingEfficiencyGraph.Evaluate(Mathf.Abs(velocity.y)/maxFallSpeed);
            velocity = new Vector2(velocity.x * (changeDir ? -1 : 1), velocity.y * -bouncingEfficiency * (changeDir ? 0:1));
            bounceData.newVelocity = velocity;

            hitPointsHistory.Add(bounceData);
        }

        velocity = new Vector2(velocity.x, velocity.y < -maxFallSpeed ? -maxFallSpeed : velocity.y);

        mover.transform.position += (Vector3)velocity * dt;

        pointsHistory.Add(mover.transform.position);

        return false;
    }


    void Simulate(){
        float fps = 60;
        float totalLength = allHits[allHits.Count-1];
        float curFrame =0;
        Reset(0);
        
        //Purge existing bouncing plats
        bouncerParent.PurgeChildrenEdit();

        int totalFrames = Mathf.CeilToInt(totalLength * fps);
        while(curFrame < totalFrames){
            if(ManualUpdate(curFrame/fps)){
                break;
            }
            curFrame++;
        }

        line.positionCount = pointsHistory.Count;
        line.SetPositions(pointsHistory.ToArray());

        foreach(BounceData data in hitPointsHistory){
            GameObject newPlat = Instantiate(bouncerPrefab, bouncerParent);
            newPlat.transform.position = data.point;
            newPlat.transform.rotation = Quaternion.AngleAxis(CalculateWallAngle(data.prevVelocity,data.newVelocity), Vector3.forward);
        }
    }

    public static float CalculateWallAngle(Vector2 previousVelocity, Vector2 newVelocity)
    {
        // Normalize velocities to ignore the speed and just focus on direction
        Vector2 previousDir = previousVelocity.normalized;
        Vector2 newDir = newVelocity.normalized;

        // The reflection vector is the difference between the two normalized velocities
        Vector2 reflectionVector = newDir - previousDir;

        // Calculate the wall normal using reflection law (midpoint of incoming and outgoing angles)
        Vector2 wallNormal = Vector2.Perpendicular(reflectionVector).normalized;

        // Calculate the angle of the wall from the wall's normal
        float wallAngle = Mathf.Atan2(wallNormal.y, wallNormal.x) * Mathf.Rad2Deg;

        // Make sure the angle is between 0 and 360 degrees
        if (wallAngle < 0) wallAngle += 360;

        return wallAngle;
    }
}


[System.Serializable]
public struct BounceData{
    public Vector3 point;
    public Vector2 prevVelocity;
    public Vector2 newVelocity;
}