Remove .gitignore do nothing is ignored.

[synfig.git] / synfig-core / trunk / src / modules / mod_particle / random.cpp

diff --git a/synfig-core/trunk/src/modules/mod_particle/random.cpp b/synfig-core/trunk/src/modules/mod_particle/random.cpp
index c72c763..ebdff92 100644 (file)
--- a/synfig-core/trunk/src/modules/mod_particle/random.cpp
+++ b/synfig-core/trunk/src/modules/mod_particle/random.cpp
@@ -6,6 +6,7 @@
 **
 **     \legal
 **     Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
+**     Copyright (c) 2007 Chris Moore
 **
 **     This package is free software; you can redistribute it and/or
 **     modify it under the terms of the GNU General Public License as
@@ -37,6 +38,8 @@
 
 /* === M A C R O S ========================================================= */
 
+#define PI     (3.1415927)
+
 /* === G L O B A L S ======================================================= */
 
 /* === P R O C E D U R E S ================================================= */
@@ -57,6 +60,10 @@ Random::set_seed(int x)
        t_mask=rand()+rand()*RAND_MAX;
 }
 
+// this picks one of the POOL_SIZE (256) preset values out of the pool
+// and scales it to be in the range (-1, 1).  is that what it was
+// intended to do?  the distribution is pretty terrible, too, with
+// some elements being picked a hundred times more often than others
 float
 Random::operator()(const int salt,const int x,const int y,const int t)const
 {
@@ -219,8 +226,8 @@ Random::operator()(SmoothType smooth,int subseed,float xf,float yf,float tf)cons
                int y((int)floor(yf));
                float a=xf-x;
                float b=yf-y;
-               a=(1.0f-cos(a*3.1415927))*0.5f;
-               b=(1.0f-cos(b*3.1415927))*0.5f;
+               a=(1.0f-cos(a*PI))*0.5f;
+               b=(1.0f-cos(b*PI))*0.5f;
                float c=1.0-a;
                float d=1.0-b;
                int x2=x+1,y2=y+1;
@@ -236,12 +243,12 @@ Random::operator()(SmoothType smooth,int subseed,float xf,float yf,float tf)cons
                float b=yf-y;
                float c=tf-t;
 
-               a=(1.0f-cos(a*3.1415927))*0.5f;
-               b=(1.0f-cos(b*3.1415927))*0.5f;
+               a=(1.0f-cos(a*PI))*0.5f;
+               b=(1.0f-cos(b*PI))*0.5f;
 
                // We don't perform this on the time axis, otherwise we won't
                // get smooth motion
-               //c=(1.0f-cos(c*3.1415927))*0.5f;
+               //c=(1.0f-cos(c*PI))*0.5f;
 
                float d=1.0-a;
                float e=1.0-b;