From b6eb09dc656bcc0f05c276319e411e81fb1ca8f2 Mon Sep 17 00:00:00 2001
From: Justin Lin <justin.sdk@gmail.com>
Date: Fri, 23 Apr 2021 08:02:14 +0800
Subject: [PATCH] sum up totalWeights directly

---
 src/experimental/_impl/_tiles_wfc_impl.scad | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/experimental/_impl/_tiles_wfc_impl.scad b/src/experimental/_impl/_tiles_wfc_impl.scad
index 788e3a89..cb5d8a63 100644
--- a/src/experimental/_impl/_tiles_wfc_impl.scad
+++ b/src/experimental/_impl/_tiles_wfc_impl.scad
@@ -1,6 +1,5 @@
 use <util/flat.scad>;
 use <util/has.scad>;
-use <util/sum.scad>;
 use <util/rand.scad>;
 use <util/slice.scad>;
 use <util/some.scad>;
@@ -83,12 +82,16 @@ function wf_collapse(wf, x, y) =
 			if(w != undef)
 			[state, w]
 		],
-		totalWeights = sum([for(w = weights_xy) w[1]]),
+		totalWeights = _totalWeights(weights_xy, len(weights_xy)),
 		threshold = rand() * totalWeights,
 		states_weights = weights_xy
 	)		
 	_wf_collapse(wf, x, y, states_weights, len(states_weights), threshold);
 
+function _totalWeights(weights_xy, leng, i = 0) =
+    i == leng ? 0 :
+	weights_xy[i][1] + _totalWeights(weights_xy, leng, i + 1);
+
 function _wf_collapse(wf, x, y, states_weights, leng, threshold, i = 0) =
     i == leng ? wf : 
 	let(