From f1a326e1cbfae384a3636134e33b53632610050e Mon Sep 17 00:00:00 2001
From: Eryn Wells <eryn@erynwells.me>
Date: Sat, 13 Oct 2018 12:41:53 -0700
Subject: [PATCH] Add sample() func to Field -- needs for two commits ago

---
 MetaballsKit/Metaballs.swift | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/MetaballsKit/Metaballs.swift b/MetaballsKit/Metaballs.swift
index 3690da6..fa1e1a3 100644
--- a/MetaballsKit/Metaballs.swift
+++ b/MetaballsKit/Metaballs.swift
@@ -178,6 +178,17 @@ public class Field {
         balls.removeAll(keepingCapacity: true)
     }
 
+    func sample(at point: Float2) -> Float {
+        var sample: Float = 0.0;
+        for b in balls {
+            let r2 = b.radius * b.radius
+            let xDiff = point.x - b.position.x
+            let yDiff = point.y - b.position.y
+            sample += r2 / (xDiff * xDiff + yDiff * yDiff)
+        }
+        return sample
+    }
+
     private func randomPoint(forBallWithRadius radius: Float) -> Float2 {
         guard Float(bounds.width) > radius && Float(bounds.height) > radius else {
             return Float2()