From 1c5a6a462afef130b31129ad8f8786831899290d Mon Sep 17 00:00:00 2001
From: Kaj Forney <kaj.forney@gmail.com>
Date: Mon, 1 Nov 2021 02:39:09 -0600
Subject: [PATCH] Better algorithm for randomizing tetromino shapes.

---
 Assets/Scripts/tetrominoSpawnManager.cs | 65 ++++++++++++++-----------
 1 file changed, 37 insertions(+), 28 deletions(-)

diff --git a/Assets/Scripts/tetrominoSpawnManager.cs b/Assets/Scripts/tetrominoSpawnManager.cs
index 1e69997..aace34a 100644
--- a/Assets/Scripts/tetrominoSpawnManager.cs
+++ b/Assets/Scripts/tetrominoSpawnManager.cs
@@ -1,3 +1,4 @@
+using System;
 using UnityEngine;
 using Random = UnityEngine.Random;
 
@@ -15,38 +16,46 @@ public class tetrominoSpawnManager : MonoBehaviour
     private int nextTetromino = 0;
     private GameObject nextTetrominoObject;
 
+    private GameObject[] nextTetrominoSequence = new GameObject[14];
+
+    public void Start()
+    {
+        nextTetrominoSequence = new GameObject[14]
+        {
+            tetrominoL, tetrominoL,
+            tetrominoLine, tetrominoLine,
+            tetrominoR, tetrominoR,
+            tetrominoS, tetrominoS,
+            tetrominoSquare, tetrominoSquare,
+            tetrominoT, tetrominoT,
+            tetrominoZ, tetrominoZ
+        };
+        
+        Shuffle(nextTetrominoSequence);
+    }
+
     public void spawnTetromino()
     {
-        nextTetromino = Random.Range(1, 7);
-        switch (nextTetromino)
+        Instantiate(nextTetrominoSequence[nextTetromino], spawnPoint, Quaternion.identity);
+        
+        nextTetromino++;
+
+        if (nextTetromino == 14)
         {
-            case 0: //Square
-                nextTetrominoObject = tetrominoSquare;
-                break;
-            case 1: //Line
-                nextTetrominoObject = tetrominoLine;
-                break;
-            case 2: //T-piece
-                nextTetrominoObject = tetrominoT;
-                break;
-            case 3: //L-piece
-                nextTetrominoObject = tetrominoL;
-                break;
-            case 4: //R-piece
-                nextTetrominoObject = tetrominoR;
-                break;
-            case 5: //S-piece
-                nextTetrominoObject = tetrominoS;
-                break;
-            case 6: //Z-piece
-                nextTetrominoObject = tetrominoZ;
-                break;
-            default: //if it's not a piece I have a prefab for yet, default to square
-                nextTetrominoObject = tetrominoSquare;
-                break;
+            nextTetromino = 0;
+            Shuffle(nextTetrominoSequence);
         }
 
-        Instantiate(nextTetrominoObject, spawnPoint, Quaternion.identity);
-
+    }
+    
+    //an algorithm for shuffling arrays, taken from https://stackoverflow.com/questions/36702548/shuffle-array-in-unity
+    void Shuffle(GameObject[] array)
+    {
+        int p = array.Length;
+        for (int n = p - 1; n > 0; n--)
+        {
+            int r = Random.Range(0, n);
+            (array[r], array[n]) = (array[n], array[r]);
+        }
     }
 }