Implement wave based spawning of enemies #11

Implements basic waves of enemies that spawn. #11

Reviewed-on: #16
Reviewed-by: zephyr <zephyr@noreply.localhost>
Co-authored-by: Michael <mep053@gmail.com>
Co-committed-by: Michael <mep053@gmail.com>

Assets/Scripts/Wave/SpawnDistribution.cs

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+namespace Wave
+{
+    public enum SpawnDistribution
+    {
+        Uniform,
+        Random,
+        DiskRandom
+    }
+}

Assets/Scripts/Wave/SpawnDistribution.cs.meta

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+fileFormatVersion: 2
+guid: 2a4df8269a27463eaf87da9ae1283dcb
+timeCreated: 1690925288

Assets/Scripts/Wave/SpawnPackSO.cs

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+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using DefaultNamespace;
+using UnityEngine;
+using UnityEngine.Assertions;
+
+namespace Wave
+{
+    [CreateAssetMenu(fileName = "SpawnPack", menuName = "Spawn/Pack", order = 0)]
+    public class SpawnPackSO : ScriptableObject
+    {
+        [SerializeField] private List<Enemy> possibleEnemies;
+        [SerializeField] [Min(0)] private int minCount;
+        [SerializeField] [Min(0)] private int maxCount;
+        
+        public ReadOnlyCollection<Enemy> EnemiesToSpawn()
+        {
+            Assert.IsTrue(possibleEnemies.Count > 0);
+            
+            var count = Random.Range(minCount, maxCount);
+            var enemiesToSpawn = new List<Enemy>();
+            
+            for (var i = 0; i < count; i++)
+            {
+                var enemyIndex = Random.Range(0, possibleEnemies.Count);
+                enemiesToSpawn.Add(possibleEnemies[enemyIndex]);
+            }
+
+            return enemiesToSpawn.AsReadOnly();
+        }
+    }
+}

Assets/Scripts/Wave/SpawnPackSO.cs.meta

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+fileFormatVersion: 2
+guid: 52673fed940f4a67b5a08641a55feff6
+timeCreated: 1690938542

Assets/Scripts/Wave/SpawnWaveSO.cs

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+using System.Collections.Generic;
+using UnityEngine;
+using UnityEngine.Serialization;
+
+namespace Wave
+{
+    [CreateAssetMenu(fileName = "SpawnWave", menuName = "Spawn Wave", order = 0)]
+    public class SpawnWaveSO : ScriptableObject
+    {
+        [SerializeField] private List<SpawnPackSO> packs;
+        [SerializeField] private SpawnDistribution distribution;
+        [SerializeField] [Min(10)] private float radius;
+        [SerializeField] [Min(0)] private float packRadius;
+        [SerializeField] [Min(0)] private float timeBetweenSpawns;
+        [SerializeField] [Min(0)] private float timeBetweenPacks;
+        [SerializeField] [Min(0)] private float timeToComplete;
+        
+        
+        public IReadOnlyCollection<SpawnPackSO> Packs => packs;
+        public SpawnDistribution Distribution => distribution;
+        public float Radius => radius;
+        public float PackRadius => packRadius;
+        public float TimeBetweenSpawns => timeBetweenSpawns;
+        public float TimeBetweenPacks => timeBetweenPacks;
+        public float TimeToComplete => timeToComplete;
+    }
+}

Assets/Scripts/Wave/SpawnWaveSO.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 17a69c35e3e64b6d9f655533478f9772
+timeCreated: 1690856578

Assets/Scripts/Wave/WaveSpawner.cs

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+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using DefaultNamespace;
+using Events;
+using UnityEngine;
+using UnityEngine.Assertions;
+using Random = UnityEngine.Random;
+
+namespace Wave
+{
+    public class WaveSpawner : MonoBehaviour
+    {
+        [SerializeField] private SpawnWaveSOEventChannelSO startNewSpawnWaveEventChannel;
+        [SerializeField] private SpawnWaveSOEventChannelSO endSpawnWaveEventChannel;
+
+        [SerializeField] private EnemyRuntimeSetSO enemyRuntimeSet;
+        [SerializeField] private Transform spawnCenter;
+        [SerializeField] private float minimumSpawnRadius;
+        [SerializeField] [Min(0)] private float timeBetweenClearedWaves;
+        [SerializeField] [Min(0)] private float timeBeforeFirstWave;
+
+        private float _timeSinceLastSpawnWaveStarted;
+        private Coroutine _handleSpawnWaves;
+
+        private bool HasWaveBeenCleared => enemyRuntimeSet.IsEmpty;
+
+        public void Begin(IEnumerable<SpawnWaveSO> spawnWaves)
+        {
+            Assert.IsNull(_handleSpawnWaves);
+            _handleSpawnWaves = StartCoroutine(CO_HandleSpawnWaves(spawnWaves));
+        }
+
+        public void End()
+        {
+            StopCoroutine(_handleSpawnWaves);
+        }
+
+        private IEnumerator CO_HandleSpawnWaves(IEnumerable<SpawnWaveSO> spawnWaves)
+        {
+            yield return new WaitForSeconds(timeBeforeFirstWave);
+
+            foreach (var spawnWave in spawnWaves)
+            {
+                startNewSpawnWaveEventChannel.RaiseEvent(spawnWave);
+                yield return SpawnWave(spawnWave);
+                _timeSinceLastSpawnWaveStarted = 0.0f;
+
+                yield return new WaitUntil(() => _timeSinceLastSpawnWaveStarted >= spawnWave.TimeToComplete || HasWaveBeenCleared);
+
+                endSpawnWaveEventChannel.RaiseEvent(spawnWave);
+
+                if (HasWaveBeenCleared)
+                {
+                    yield return new WaitForSeconds(timeBetweenClearedWaves);
+                }
+            }
+        }
+
+        private IEnumerator SpawnWave(SpawnWaveSO spawnWave)
+        {
+            var enemyPacksToSpawn = spawnWave.Packs.Select(pack => pack.EnemiesToSpawn()).ToList().AsReadOnly();
+            
+            for (var packN = 0; packN < enemyPacksToSpawn.Count; packN++)
+            {
+                var waveCompletionPercentage = (float)packN / (float)enemyPacksToSpawn.Count;
+
+                var enemyPackSpawnOffset = SampleSpawnOffset(spawnWave.Distribution, spawnWave.Radius, waveCompletionPercentage);
+                enemyPackSpawnOffset += enemyPackSpawnOffset.normalized * (minimumSpawnRadius + spawnWave.PackRadius);
+
+                var enemyPackSpawnPosition = spawnCenter.position + enemyPackSpawnOffset;
+
+                var enemyPackToSpawn = enemyPacksToSpawn[packN];
+                for (var enemyN = 0; enemyN < enemyPackToSpawn.Count; enemyN++)
+                {
+                    var packCompletionPercentage = (float)enemyN / (float)enemyPackToSpawn.Count;
+                    var enemySpawnOffset = SampleSpawnOffset(SpawnDistribution.DiskRandom, spawnWave.PackRadius, packCompletionPercentage);
+                    var enemySpawnPosition = enemyPackSpawnPosition + enemySpawnOffset;
+                    
+                    var spawnedEnemy = Instantiate(enemyPackToSpawn[enemyN], enemySpawnPosition, Quaternion.identity);
+                    enemyRuntimeSet.Add(spawnedEnemy);
+
+                    if (spawnWave.TimeBetweenSpawns > 0.0f)
+                    {
+                        yield return new WaitForSeconds(spawnWave.TimeBetweenSpawns);
+                    }
+
+                }
+                
+                if (spawnWave.TimeBetweenPacks > 0.0f)
+                {
+                    yield return new WaitForSeconds(spawnWave.TimeBetweenPacks);
+                }
+            }
+        }
+
+        private static Vector3 SampleSpawnOffset(SpawnDistribution distribution, float radius, float completionPercentage)
+        {
+            // TODO (Michael): Both the pack and enemy position samplers need to be a bit smarter. I think in most scenarios the pack circle just needs to not overlap with other pack circles. 
+            // The enemy spawns probably need something like a poission disk sampler so that monsters dont overlap. The enemy spawn radius at the pack's position should also probably scale with the size of the pack.
+            var angle = completionPercentage * 2 * MathF.PI;
+            var unitCirclePosition = Random.insideUnitCircle;
+            var swizzledUnitCirclePosition = new Vector3(unitCirclePosition.x, 0, unitCirclePosition.y);
+            
+            return distribution switch
+            {
+                SpawnDistribution.Uniform => new Vector3(Mathf.Cos(angle), 0, Mathf.Sin(angle)) * radius,
+                SpawnDistribution.Random => swizzledUnitCirclePosition.normalized *  radius,
+                SpawnDistribution.DiskRandom => swizzledUnitCirclePosition *  radius,
+                _ => throw new ArgumentOutOfRangeException(nameof(distribution), distribution, null)
+            };
+        }
+
+        private void Update()
+        {
+            _timeSinceLastSpawnWaveStarted += Time.deltaTime;
+        }
+    }
+}

Assets/Scripts/Wave/WaveSpawner.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: bb718e52728142e4a8db081fd6a36a70
+timeCreated: 1690856916