Shitty uniform Poisson Disk Sampling

This is just a very basic implementation of the algorithm, just to test and for me to understand it better, next commit I'm gonna implement the last version of it with variable density

Assets/Scripts/PoissonDiskSampling/PoissonDiskSampling.cs

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+using System;
+using System.Collections;
+using System.Collections.Generic;
+using Unity.Mathematics;
+using UnityEngine;
+using Random = UnityEngine.Random;
+
+public static class PoissonDiskSampling
+{
+    public static List<Vector2> PoissonGenerate(float radius, Vector2 sampleRegionSize,
+        int numSamplesBeforeRejection = 30)
+    {
+        float cellSize = radius / Mathf.Sqrt(2);
+
+        int[,] grid = new int[Mathf.CeilToInt(sampleRegionSize.x / cellSize), Mathf.CeilToInt(sampleRegionSize.y / cellSize)];
+        List<Vector2> points = new List<Vector2>();
+        List<Vector2> spawnPoints = new List<Vector2>();
+        spawnPoints.Add(sampleRegionSize / 2);
+        
+        while (spawnPoints.Count > 0)
+        {
+            int spawnIndex = Random.Range(0, spawnPoints.Count);
+            Vector2 spawnCentre = spawnPoints[spawnIndex];
+            bool isCandidateAccepted = false;
+            
+            for (int i = 0; i < numSamplesBeforeRejection; i++)
+            {
+                float angle = Random.value * Mathf.PI * 2;
+                Vector2 dir = new Vector2(Mathf.Sin(angle), Mathf.Cos(angle));
+                Vector2 candidate = spawnCentre + dir * Random.Range(radius, 2 * radius);
+                if (IsValid(candidate, sampleRegionSize, cellSize, radius, points, grid))
+                {
+                    points.Add(candidate);
+                    spawnPoints.Add(candidate);
+                    grid[(int)(candidate.x / cellSize), (int)(candidate.y / cellSize)] = points.Count;
+                    isCandidateAccepted = true;
+                    break;
+                }
+            }
+            if (!isCandidateAccepted)
+                spawnPoints.RemoveAt(spawnIndex);
+        }
+
+        return points;
+    }
+
+    static bool IsValid(Vector2 candidate, Vector2 sampleRegionSize, float cellSize, float radius, List<Vector2> points, int[,] grid)
+    {
+        if (candidate.x >= 0 && candidate.x < sampleRegionSize.x && candidate.y >= 0 && candidate.y < sampleRegionSize.y)
+        {
+            int cellX = (int) (candidate.x / cellSize);
+            int cellY = (int) (candidate.y / cellSize);
+            int searchStartX = Mathf.Max(0, cellX - 2);
+            int searchEndX = Mathf.Min(cellX + 2, grid.GetLength(0) - 1);
+            int searchStartY = Mathf.Max(0, cellY - 2);
+            int searchEndY = Mathf.Min(cellY + 2, grid.GetLength(1) - 1);
+
+            for (int x = searchStartX; x <= searchEndX; x++)
+            {
+                for (int y = searchStartY; y <= searchEndY; y++)
+                {
+                    int pointIndex = grid[x, y] - 1;
+                    if (pointIndex != -1)
+                    {
+                        float sqrDst = (candidate - points[pointIndex]).sqrMagnitude;
+                        if (sqrDst < radius * radius)
+                        {
+                            return false;
+                        }
+                    }
+                }
+            }
+
+            return true;
+        }
+
+        return false;
+    }
+    
+    // float squaredEuclideanDistance(Array point1, Array point2)
+    // {
+    //     
+    // }
+    //
+    //
+    // void PoissonDiskGenerate()
+    // {
+    //     
+    // }
+}

Assets/Scripts/PoissonDiskSampling/PoissonDiskSampling.cs.meta

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Assets/Scripts/PoissonDiskSampling/Test.cs

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+using System;
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class Test : MonoBehaviour
+{
+    public float radius = 1;
+    public Vector2 regionSize = Vector2.one;
+    public int rejectionSamples = 30;
+    public float displayRadius = 1;
+
+    private List<Vector2> points;
+
+    private void OnValidate()
+    {
+        points = PoissonDiskSampling.PoissonGenerate(radius, regionSize, rejectionSamples);
+    }
+
+    private void OnDrawGizmos()
+    {
+        Gizmos.DrawWireCube(regionSize/2, regionSize);
+        
+        if (points != null)
+        {
+            foreach (Vector2 p in points)
+            {
+                Gizmos.DrawSphere(p, displayRadius);
+            }
+        }
+    }
+}

Assets/Scripts/PoissonDiskSampling/Test.cs.meta

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