/*! \file mod_noise/random.cpp
** \brief blehh
**
-** $Id: random.cpp,v 1.6 2005/01/17 02:00:19 darco Exp $
+** $Id$
**
** \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
#endif
#include "random.h"
+#include <synfig/quick_rng.h>
#include <cmath>
#include <cstdlib>
#endif
-// A fast 32-bit linear congruential random number generator
-class quick_rng
-{
- unsigned long next;
-public:
- quick_rng(unsigned long seed):next(seed) { }
-
- void set_seed(unsigned long x)
- {
- next=x;
- }
-
- unsigned long i32()
- {
- static const unsigned long a(1664525);
- static const unsigned long c(1013904223);
-
- return next=next*a+c;
- }
-
- unsigned long i16()
- {
- return i32()>>16;
- }
-
- float f()
- {
- static const float m(int(65535));
-
- return float(i16())/m;
- }
-};
-
/* === M A C R O S ========================================================= */
#define PI (3.1415927)
}
float
-Random::operator()(int smooth,int subseed,float xf,float yf,float tf)const
+Random::operator()(SmoothType smooth,int subseed,float xf,float yf,float tf)const
{
int x((int)floor(xf));
int y((int)floor(yf));
switch(smooth)
{
- case 4: // cubic
+ case SMOOTH_CUBIC: // cubic
{
#define f(j,i,k) ((*this)(subseed,i,j,k))
//Using catmull rom interpolation because it doesn't blur at all
+ // ( http://www.gamedev.net/reference/articles/article1497.asp )
//bezier curve with intermediate ctrl pts: 0.5/3(p(i+1) - p(i-1)) and similar
float xfa [4], tfa[4];
//precalculate indices (all clamped) and offset
const int xa[] = {x-1,x,x+1,x+2};
-
const int ya[] = {y-1,y,y+1,y+2};
-
const int ta[] = {t-1,t,t+1,t+2};
const float dx(xf-x);
break;
- case 5: // Fast Spline (non-animated)
+ case SMOOTH_FAST_SPLINE: // Fast Spline (non-animated)
{
#define P(x) (((x)>0)?((x)*(x)*(x)):0.0f)
#define R(x) ( P(x+2) - 4.0f*P(x+1) + 6.0f*P(x) - 4.0f*P(x-1) )*(1.0f/6.0f)
#define FT(i,j,k) ((*this)(subseed,i+x,j+y,k+t)*(R((i)-a)*R(b-(j))*R((k)-c)))
#define Z(i,j) ret+=F(i,j)
#define ZT(i,j,k) ret+=FT(i,j,k)
-#define X(i,j) // placeholder... To make box more symetric
-#define XT(i,j,k) // placeholder... To make box more symetric
+#define X(i,j) // placeholder... To make box more symmetric
+#define XT(i,j,k) // placeholder... To make box more symmetric
float a(xf-x), b(yf-y);
return ret;
}
- case 3: // Spline (animated)
+ case SMOOTH_SPLINE: // Spline (animated)
{
float a(xf-x), b(yf-y), c(tf-t);
#undef P
#undef R
- case 2: // Cosine
+ case SMOOTH_COSINE:
if((float)t==tf)
{
int x((int)floor(xf));
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;
(*this)(subseed,x,y2,t2)*(d*b*c)+
(*this)(subseed,x2,y2,t2)*(a*b*c);
}
- case 1: // Linear
+ case SMOOTH_LINEAR:
if((float)t==tf)
{
int x((int)floor(xf));
(*this)(subseed,x2,y2,t2)*(a*b*c);
}
default:
- case 0:
+ case SMOOTH_DEFAULT:
return (*this)(subseed,x,y,t);
}
}