A possible problem was noted by Cyril Brulebois regarding copyright issues

with regards to the noise functions in yafray based on Ken Musgrave's
original code.
I had left the 'Copyright' notice in the comments, and according to
Cyril Brulebois this is a problem. In fact, from what I understand this
makes it even impossible to use or modify the code in other software.
But since it is not a verbatim copy of the code but rather based on Musgrave's
work, he suggested I change it to explicitely state that it is in fact
based on the code from the 'Texturing & Modeling' book.
And since the yafray code is in turn based on the blender code, I better
adapt the blender code too.

This reminded me that I also have forgotten to include the copyright notice
in the mersenne twister rng code I used for the Python Noise module.
This does clearly state to include the original notice with any resdistributed
code, in modified form or not. So I added that too.

I hope that solves the problems.

2 files changed, 53 insertions, 21 deletions

diff --git a/source/blender/blenlib/intern/noise.c b/source/blender/blenlib/intern/noise.c
index 3a2dd12a804..4fa2d1fdd48 100644
--- a/source/blender/blenlib/intern/noise.c
+++ b/source/blender/blenlib/intern/noise.c
@@ -946,20 +946,14 @@ float BLI_gTurbulence(float noisesize, float x, float y, float z, int oct, int h
 }
 
 
-/*************************************/
-/*  NOISE FUNCTIONS BY KEN MUSGRAVE  */
-/* Copyright 1994 F. Kenton Musgrave */
-/*************************************/
-
-/* All of these are modified to be able to use them with different noisebasis.
-   In some cases the original code seemed to contain errors, so it is not exactly
-   the same now as the orginal code (from "Texturing and Modelling: A procedural approach") */
+/*
+ * The following code is based on Ken Musgrave's explanations and sample
+ * source code in the book "Texturing and Modelling: A procedural approach"
+ */
 
 /*
  * Procedural fBm evaluated at "point"; returns value stored in "value".
  *
- * Copyright 1994 F. Kenton Musgrave
- *
  * Parameters:
  *    ``H''  is the fractal increment parameter
  *    ``lacunarity''  is the gap between successive frequencies
@@ -1025,8 +1019,6 @@ float mg_fBm(float x, float y, float z, float H, float lacunarity, float octaves
  * Procedural multifractal evaluated at "point";
  * returns value stored in "value".
  *
- * Copyright 1994 F. Kenton Musgrave
- *
  * Parameters:
  *    ``H''  determines the highest fractal dimension
  *    ``lacunarity''  is gap between successive frequencies
@@ -1094,8 +1086,6 @@ float mg_MultiFractal(float x, float y, float z, float H, float lacunarity, floa
  * Heterogeneous procedural terrain function: stats by altitude method.
  * Evaluated at "point"; returns value stored in "value".
  *
- * Copyright 1994 F. Kenton Musgrave
- *
  * Parameters:
  *       ``H''  determines the fractal dimension of the roughest areas
  *       ``lacunarity''  is the gap between successive frequencies
@@ -1170,8 +1160,6 @@ float mg_HeteroTerrain(float x, float y, float z, float H, float lacunarity, flo
 
 /* Hybrid additive/multiplicative multifractal terrain model.
  *
- * Copyright 1994 F. Kenton Musgrave
- *
  * Some good parameter values to start with:
  *
  *      H:           0.25
@@ -1246,8 +1234,6 @@ float mg_HybridMultiFractal(float x, float y, float z, float H, float lacunarity
 
 /* Ridged multifractal terrain model.
  *
- * Copyright 1994 F. Kenton Musgrave
- *
  * Some good parameter values to start with:
  *
  *      H:           1.0
@@ -1319,8 +1305,6 @@ float mg_RidgedMultiFractal(float x, float y, float z, float H, float lacunarity
 
 /* "Variable Lacunarity Noise"
  * A distorted variety of Perlin noise.
- *
- * Copyright 1994 F. Kenton Musgrave
  */
 float mg_VLNoise(float x, float y, float z, float distortion, int nbas1, int nbas2)
 {
diff --git a/source/blender/python/api2_2x/Noise.c b/source/blender/python/api2_2x/Noise.c
index 060dedb9801..14a254ebcd0 100644
--- a/source/blender/python/api2_2x/Noise.c
+++ b/source/blender/python/api2_2x/Noise.c
@@ -45,6 +45,52 @@
 
 /*-----------------------------------------*/
 /* 'mersenne twister' random number generator */
+
+/* 
+   A C-program for MT19937, with initialization improved 2002/2/10.
+   Coded by Takuji Nishimura and Makoto Matsumoto.
+   This is a faster version by taking Shawn Cokus's optimization,
+   Matthe Bellew's simplification, Isaku Wada's real version.
+
+   Before using, initialize the state by using init_genrand(seed) 
+   or init_by_array(init_key, key_length).
+
+   Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
+   All rights reserved.                          
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions
+   are met:
+
+     1. Redistributions of source code must retain the above copyright
+        notice, this list of conditions and the following disclaimer.
+
+     2. Redistributions in binary form must reproduce the above copyright
+        notice, this list of conditions and the following disclaimer in the
+        documentation and/or other materials provided with the distribution.
+
+     3. The names of its contributors may not be used to endorse or promote 
+        products derived from this software without specific prior written 
+        permission.
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+   A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+   Any feedback is very welcome.
+   http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html
+   email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space)
+*/
+
 /* Period parameters */
 #define N 624
 #define M 397
@@ -112,7 +158,7 @@ static void setRndSeed( int seed )
 		init_genrand( seed );
 }
 
-/* float number in range [0, 1) */
+/* float number in range [0, 1) using the mersenne twister rng */
 static float frand(  )
 {
 	unsigned long y;
@@ -130,6 +176,8 @@ static float frand(  )
 	return ( float ) y / 4294967296.f;
 }
 
+/*------------------------------------------------------------*/
+
 /* returns random unit vector */
 static void randuvec( float v[3] )
 {