From 49bc39771882cf53cc95d381d87f48dd6f90e5e5 Mon Sep 17 00:00:00 2001
From: Gael-de-Sailly <gael.chretien@akeonet.com>
Date: Sun, 26 Apr 2020 16:52:40 +0200
Subject: [PATCH] Fix parameters for Simplex noise, to make sure the last
 octave has not a greater scale than 1 Also use a 401x401 grid instead of 400,
 so that there are 400 intervals

---
 terrain_rivers.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/terrain_rivers.py b/terrain_rivers.py
index aad0f91..2df2f7f 100755
--- a/terrain_rivers.py
+++ b/terrain_rivers.py
@@ -15,15 +15,15 @@ argc = len(sys.argv)
 if argc > 1:
 	mapsize = int(sys.argv[1])
 else:
-	mapsize = 400
+	mapsize = 401
 
-scale = mapsize / 2
+scale = (mapsize-1) / 2
 n = np.zeros((mapsize, mapsize))
 
 #micronoise_depth = 0.05
 
 params = {
-    "octaves" : int(np.log2(mapsize)),
+    "octaves" : int(np.ceil(np.log2(mapsize-1)))+1,
     "persistence" : 0.5,
     "lacunarity" : 2.,
 }