From d842c5d28da14cb1ed3fb5e6bb4af76d8a5190a4 Mon Sep 17 00:00:00 2001
From: vrld <vrld@vrld.org>
Date: Tue, 26 Feb 2013 10:37:42 +0100
Subject: [PATCH] Fix box muller transform in common/math.cpp.

Random numbers have to be in (0:1], not in [0:1).
---
 src/common/math.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/common/math.cpp b/src/common/math.cpp
index facece23d..41c881518 100644
--- a/src/common/math.cpp
+++ b/src/common/math.cpp
@@ -24,8 +24,8 @@ float random_normal(float o)
 	}
 
 	// else: generate numbers using the Box-Muller transform
-	float a = sqrt(-2.0f * log(random()));
-	float b = float(LOVE_M_PI) * 2.0f * random();
+	float a = sqrt(-2.0f * log(1. - random()));
+	float b = float(LOVE_M_PI) * 2.0f * (1. - random());
 	last_randnormal = a * cos(b);
 	return a * sin(b) * o;
 }