--- /dev/null
+/* === S Y N F I G ========================================================= */
+/*! \file mod_particle/random.cpp
+** \brief blehh
+**
+** $Id$
+**
+** \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
+** published by the Free Software Foundation; either version 2 of
+** the License, or (at your option) any later version.
+**
+** This package is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+** General Public License for more details.
+** \endlegal
+*/
+/* ========================================================================= */
+
+/* === H E A D E R S ======================================================= */
+
+#ifdef USING_PCH
+# include "pch.h"
+#else
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "random.h"
+#include <cmath>
+#include <cstdlib>
+
+#endif
+
+/* === 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 ================================================= */
+
+/* === M E T H O D S ======================================================= */
+
+void
+Random::set_seed(int x)
+{
+ seed_=x;
+ srand(x);
+ int i;
+ for(i=0;i<POOL_SIZE;i++)
+ pool_[i]=rand();
+
+ x_mask=rand()+rand()*RAND_MAX;
+ y_mask=rand()+rand()*RAND_MAX;
+ 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
+{
+ const int salt_hash(pool_[salt&(POOL_SIZE-1)]);
+
+ int index(((x^x_mask)+(y^y_mask)*234672+(t^t_mask)*8439573)^salt_hash);
+
+ index+=index*(index/POOL_SIZE);
+
+ return (float(pool_[index&(POOL_SIZE-1)])/float(RAND_MAX))*2.0f-1.0f;
+}
+
+float
+Random::operator()(SmoothType smooth,int subseed,float xf,float yf,float tf)const
+{
+ int x((int)floor(xf));
+ int y((int)floor(yf));
+ int t((int)floor(tf));
+
+ switch(smooth)
+ {
+ 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);
+ const float dy(yf-y);
+ const float dt(tf-t);
+
+ //figure polynomials for each point
+ const float txf[] =
+ {
+ 0.5*dx*(dx*(dx*(-1) + 2) - 1), //-t + 2t^2 -t^3
+ 0.5*(dx*(dx*(3*dx - 5)) + 2), //2 - 5t^2 + 3t^3
+ 0.5*dx*(dx*(-3*dx + 4) + 1), //t + 4t^2 - 3t^3
+ 0.5*dx*dx*(dx-1) //-t^2 + t^3
+ };
+
+ const float tyf[] =
+ {
+ 0.5*dy*(dy*(dy*(-1) + 2) - 1), //-t + 2t^2 -t^3
+ 0.5*(dy*(dy*(3*dy - 5)) + 2), //2 - 5t^2 + 3t^3
+ 0.5*dy*(dy*(-3*dy + 4) + 1), //t + 4t^2 - 3t^3
+ 0.5*dy*dy*(dy-1) //-t^2 + t^3
+ };
+
+ const float ttf[] =
+ {
+ 0.5*dt*(dt*(dt*(-1) + 2) - 1), //-t + 2t^2 -t^3
+ 0.5*(dt*(dt*(3*dt - 5)) + 2), //2 - 5t^2 + 3t^3
+ 0.5*dt*(dt*(-3*dt + 4) + 1), //t + 4t^2 - 3t^3
+ 0.5*dt*dt*(dt-1) //-t^2 + t^3
+ };
+
+ //evaluate polynomial for each row
+ for(int i = 0; i < 4; ++i)
+ {
+ for(int j = 0; j < 4; ++j)
+ {
+ tfa[j] = f(ya[i],xa[j],ta[0])*ttf[0] + f(ya[i],xa[j],ta[1])*ttf[1] + f(ya[i],xa[j],ta[2])*ttf[2] + f(ya[i],xa[j],ta[3])*ttf[3];
+ }
+ xfa[i] = tfa[0]*txf[0] + tfa[1]*txf[1] + tfa[2]*txf[2] + tfa[3]*txf[3];
+ }
+
+ //return the cumulative column evaluation
+ return xfa[0]*tyf[0] + xfa[1]*tyf[1] + xfa[2]*tyf[2] + xfa[3]*tyf[3];
+#undef f
+ }
+ break;
+
+
+ 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 F(i,j) ((*this)(subseed,i+x,j+y)*(R((i)-a)*R(b-(j))))
+#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 symmetric
+#define XT(i,j,k) // placeholder... To make box more symmetric
+
+ float a(xf-x), b(yf-y);
+
+ // Interpolate
+ float ret(F(0,0));
+ Z(-1,-1); Z(-1, 0); Z(-1, 1); Z(-1, 2);
+ Z( 0,-1); X( 0, 0); Z( 0, 1); Z( 0, 2);
+ Z( 1,-1); Z( 1, 0); Z( 1, 1); Z( 1, 2);
+ Z( 2,-1); Z( 2, 0); Z( 2, 1); Z( 2, 2);
+
+ return ret;
+ }
+
+ case SMOOTH_SPLINE: // Spline (animated)
+ {
+ float a(xf-x), b(yf-y), c(tf-t);
+
+ // Interpolate
+ float ret(FT(0,0,0));
+ ZT(-1,-1,-1); ZT(-1, 0,-1); ZT(-1, 1,-1); ZT(-1, 2,-1);
+ ZT( 0,-1,-1); ZT( 0, 0,-1); ZT( 0, 1,-1); ZT( 0, 2,-1);
+ ZT( 1,-1,-1); ZT( 1, 0,-1); ZT( 1, 1,-1); ZT( 1, 2,-1);
+ ZT( 2,-1,-1); ZT( 2, 0,-1); ZT( 2, 1,-1); ZT( 2, 2,-1);
+
+ ZT(-1,-1, 0); ZT(-1, 0, 0); ZT(-1, 1, 0); ZT(-1, 2, 0);
+ ZT( 0,-1, 0); XT( 0, 0, 0); ZT( 0, 1, 0); ZT( 0, 2, 0);
+ ZT( 1,-1, 0); ZT( 1, 0, 0); ZT( 1, 1, 0); ZT( 1, 2, 0);
+ ZT( 2,-1, 0); ZT( 2, 0, 0); ZT( 2, 1, 0); ZT( 2, 2, 0);
+
+ ZT(-1,-1, 1); ZT(-1, 0, 1); ZT(-1, 1, 1); ZT(-1, 2, 1);
+ ZT( 0,-1, 1); ZT( 0, 0, 1); ZT( 0, 1, 1); ZT( 0, 2, 1);
+ ZT( 1,-1, 1); ZT( 1, 0, 1); ZT( 1, 1, 1); ZT( 1, 2, 1);
+ ZT( 2,-1, 1); ZT( 2, 0, 1); ZT( 2, 1, 1); ZT( 2, 2, 1);
+
+ ZT(-1,-1, 2); ZT(-1, 0, 2); ZT(-1, 1, 2); ZT(-1, 2, 2);
+ ZT( 0,-1, 2); ZT( 0, 0, 2); ZT( 0, 1, 2); ZT( 0, 2, 2);
+ ZT( 1,-1, 2); ZT( 1, 0, 2); ZT( 1, 1, 2); ZT( 1, 2, 2);
+ ZT( 2,-1, 2); ZT( 2, 0, 2); ZT( 2, 1, 2); ZT( 2, 2, 2);
+
+ return ret;
+
+/*
+
+ float dx=xf-x;
+ float dy=yf-y;
+ float dt=tf-t;
+
+ float ret=0;
+ int i,j,h;
+ for(h=-1;h<=2;h++)
+ for(i=-1;i<=2;i++)
+ for(j=-1;j<=2;j++)
+ ret+=(*this)(subseed,i+x,j+y,h+t)*(R(i-dx)*R(j-dy)*R(h-dt));
+ return ret;
+*/
+ }
+ break;
+#undef X
+#undef Z
+#undef F
+#undef P
+#undef R
+
+ case SMOOTH_COSINE:
+ if((float)t==tf)
+ {
+ int x((int)floor(xf));
+ int y((int)floor(yf));
+ float a=xf-x;
+ float b=yf-y;
+ 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;
+ return
+ (*this)(subseed,x,y,t)*(c*d)+
+ (*this)(subseed,x2,y,t)*(a*d)+
+ (*this)(subseed,x,y2,t)*(c*b)+
+ (*this)(subseed,x2,y2,t)*(a*b);
+ }
+ else
+ {
+ float a=xf-x;
+ float b=yf-y;
+ float c=tf-t;
+
+ 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*PI))*0.5f;
+
+ float d=1.0-a;
+ float e=1.0-b;
+ float f=1.0-c;
+
+ int x2=x+1,y2=y+1,t2=t+1;
+
+ return
+ (*this)(subseed,x,y,t)*(d*e*f)+
+ (*this)(subseed,x2,y,t)*(a*e*f)+
+ (*this)(subseed,x,y2,t)*(d*b*f)+
+ (*this)(subseed,x2,y2,t)*(a*b*f)+
+ (*this)(subseed,x,y,t2)*(d*e*c)+
+ (*this)(subseed,x2,y,t2)*(a*e*c)+
+ (*this)(subseed,x,y2,t2)*(d*b*c)+
+ (*this)(subseed,x2,y2,t2)*(a*b*c);
+ }
+ case SMOOTH_LINEAR:
+ if((float)t==tf)
+ {
+ int x((int)floor(xf));
+ int y((int)floor(yf));
+ float a=xf-x;
+ float b=yf-y;
+ float c=1.0-a;
+ float d=1.0-b;
+ int x2=x+1,y2=y+1;
+ return
+ (*this)(subseed,x,y,t)*(c*d)+
+ (*this)(subseed,x2,y,t)*(a*d)+
+ (*this)(subseed,x,y2,t)*(c*b)+
+ (*this)(subseed,x2,y2,t)*(a*b);
+ }
+ else
+ {
+
+ float a=xf-x;
+ float b=yf-y;
+ float c=tf-t;
+
+ float d=1.0-a;
+ float e=1.0-b;
+ float f=1.0-c;
+
+ int x2=x+1,y2=y+1,t2=t+1;
+
+ return
+ (*this)(subseed,x,y,t)*(d*e*f)+
+ (*this)(subseed,x2,y,t)*(a*e*f)+
+ (*this)(subseed,x,y2,t)*(d*b*f)+
+ (*this)(subseed,x2,y2,t)*(a*b*f)+
+ (*this)(subseed,x,y,t2)*(d*e*c)+
+ (*this)(subseed,x2,y,t2)*(a*e*c)+
+ (*this)(subseed,x,y2,t2)*(d*b*c)+
+ (*this)(subseed,x2,y2,t2)*(a*b*c);
+ }
+ default:
+ case SMOOTH_DEFAULT:
+ return (*this)(subseed,x,y,t);
+ }
+}
projects / synfig.git / blobdiff