campfire/Assets/Scripts/LoraxCuller.cs

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

public class LoraxCuller : MonoBehaviour {
    public Lorax[] Loraces;
    public int[] Radius;
    public bool[] Omnidirectional;
    public bool CullingStatusChanged = false;

    private HashSet<GameObject> OldChunks = new HashSet<GameObject>();
    private int LastX = int.MaxValue;
    private int LastY = int.MaxValue;
    private int LastAngle = int.MaxValue;

    private void Update() {
        if (Loraces.Length == 0) {
            // Not in the world of the lorax yet.
            return;
        }

        int BaseX = Mathf.FloorToInt(transform.position.x / 20) * 20 + 10;
        int BaseY = Mathf.FloorToInt(transform.position.z / 20) * 20 + 10;
        int Angle = Mathf.FloorToInt(transform.localEulerAngles.y / 5) * 5;
        if (BaseX == LastX && BaseY == LastY && Angle == LastAngle) {
            return;
        }
        LastX = BaseX;
        LastY = BaseY;
        LastAngle = Angle;

        HashSet<GameObject> EnabledChunks = new HashSet<GameObject>();
        for (int LoraxIndex = 0; LoraxIndex < Loraces.Length; LoraxIndex++) {
            Lorax Lorax = Loraces[LoraxIndex];
            for (float X = BaseX - Radius[LoraxIndex]; X <= BaseX + Radius[LoraxIndex]; X += 10) {
                for (float Y = BaseY - Radius[LoraxIndex]; Y <= BaseY + Radius[LoraxIndex]; Y += 10) {
                    if (!Omnidirectional[LoraxIndex]) {
                        Vector3 Delta = new Vector3(X - BaseX, 0, Y - BaseY);
                        if (Delta.magnitude > Mathf.Sqrt(Mathf.Pow(20, 2) * 2)) {
                            if (Vector3.Dot(Delta.normalized, transform.forward) < -0.2) {
                                continue;
                            }
                        }
                    }

                    GameObject Chunk = Lorax.GetChunkAt(X, Y);
                    if (Chunk != null) {
                        Chunk.SetActive(true);
                        EnabledChunks.Add(Chunk);
                    }
                }
            }
        }

        CullingStatusChanged = false;
        foreach (GameObject OldChunk in OldChunks) {
            if (!EnabledChunks.Contains(OldChunk)) {
                OldChunk.SetActive(false);
                CullingStatusChanged = true;
            }
        }
        if (EnabledChunks.Count > OldChunks.Count) {
            CullingStatusChanged = true;
        }
        OldChunks = EnabledChunks;
    }
}