synfig-core/tags/synfig_0_61_06/src/modules/mod_particle/random.cpp

   1 /* === S Y N F I G ========================================================= */
   2 /*!     \file mod_particle/random.cpp
   3 **      \brief blehh
   4 **
   5 **      $Id$
   6 **
   7 **      \legal
   8 **      Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
   9 **
  10 **      This package is free software; you can redistribute it and/or
  11 **      modify it under the terms of the GNU General Public License as
  12 **      published by the Free Software Foundation; either version 2 of
  13 **      the License, or (at your option) any later version.
  14 **
  15 **      This package is distributed in the hope that it will be useful,
  16 **      but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 **      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18 **      General Public License for more details.
  19 **      \endlegal
  20 */
  21 /* ========================================================================= */
  22
  23 /* === H E A D E R S ======================================================= */
  24
  25 #ifdef USING_PCH
  26 #       include "pch.h"
  27 #else
  28 #ifdef HAVE_CONFIG_H
  29 #       include <config.h>
  30 #endif
  31
  32 #include "random.h"
  33 #include <cmath>
  34 #include <cstdlib>
  35
  36 #endif
  37
  38 /* === M A C R O S ========================================================= */
  39
  40 /* === G L O B A L S ======================================================= */
  41
  42 /* === P R O C E D U R E S ================================================= */
  43
  44 /* === M E T H O D S ======================================================= */
  45
  46 void
  47 Random::set_seed(int x)
  48 {
  49         seed_=x;
  50         srand(x);
  51         int i;
  52         for(i=0;i<POOL_SIZE;i++)
  53                 pool_[i]=rand();
  54
  55         x_mask=rand()+rand()*RAND_MAX;
  56         y_mask=rand()+rand()*RAND_MAX;
  57         t_mask=rand()+rand()*RAND_MAX;
  58 }
  59
  60 float
  61 Random::operator()(const int salt,const int x,const int y,const int t)const
  62 {
  63         const int salt_hash(pool_[salt&(POOL_SIZE-1)]);
  64
  65         int index(((x^x_mask)+(y^y_mask)*234672+(t^t_mask)*8439573)^salt_hash);
  66
  67         index+=index*(index/POOL_SIZE);
  68
  69         return (float(pool_[index&(POOL_SIZE-1)])/float(RAND_MAX))*2.0f-1.0f;
  70 }
  71
  72 float
  73 Random::operator()(int smooth,int subseed,float xf,float yf,float tf)const
  74 {
  75         int x((int)floor(xf));
  76         int y((int)floor(yf));
  77         int t((int)floor(tf));
  78
  79         switch(smooth)
  80         {
  81         case 4: // cubic
  82                 {
  83                         #define f(j,i,k)        ((*this)(subseed,i,j,k))
  84                         //Using catmull rom interpolation because it doesn't blur at all
  85                         //bezier curve with intermediate ctrl pts: 0.5/3(p(i+1) - p(i-1)) and similar
  86                         float xfa [4], tfa[4];
  87
  88                         //precalculate indices (all clamped) and offset
  89                         const int xa[] = {x-1,x,x+1,x+2};
  90
  91                         const int ya[] = {y-1,y,y+1,y+2};
  92
  93                         const int ta[] = {t-1,t,t+1,t+2};
  94
  95                         const float dx(xf-x);
  96                         const float dy(yf-y);
  97                         const float dt(tf-t);
  98
  99                         //figure polynomials for each point
 100                         const float txf[] =
 101                         {
 102                                 0.5*dx*(dx*(dx*(-1) + 2) - 1),  //-t + 2t^2 -t^3
 103                                 0.5*(dx*(dx*(3*dx - 5)) + 2),   //2 - 5t^2 + 3t^3
 104                                 0.5*dx*(dx*(-3*dx + 4) + 1),    //t + 4t^2 - 3t^3
 105                                 0.5*dx*dx*(dx-1)                                //-t^2 + t^3
 106                         };
 107
 108                         const float tyf[] =
 109                         {
 110                                 0.5*dy*(dy*(dy*(-1) + 2) - 1),  //-t + 2t^2 -t^3
 111                                 0.5*(dy*(dy*(3*dy - 5)) + 2),   //2 - 5t^2 + 3t^3
 112                                 0.5*dy*(dy*(-3*dy + 4) + 1),    //t + 4t^2 - 3t^3
 113                                 0.5*dy*dy*(dy-1)                                //-t^2 + t^3
 114                         };
 115
 116                         const float ttf[] =
 117                         {
 118                                 0.5*dt*(dt*(dt*(-1) + 2) - 1),  //-t + 2t^2 -t^3
 119                                 0.5*(dt*(dt*(3*dt - 5)) + 2),   //2 - 5t^2 + 3t^3
 120                                 0.5*dt*(dt*(-3*dt + 4) + 1),    //t + 4t^2 - 3t^3
 121                                 0.5*dt*dt*(dt-1)                                //-t^2 + t^3
 122                         };
 123
 124                         //evaluate polynomial for each row
 125                         for(int i = 0; i < 4; ++i)
 126                         {
 127                                 for(int j = 0; j < 4; ++j)
 128                                 {
 129                                         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];
 130                                 }
 131                                 xfa[i] = tfa[0]*txf[0] + tfa[1]*txf[1] + tfa[2]*txf[2] + tfa[3]*txf[3];
 132                         }
 133
 134                         //return the cumulative column evaluation
 135                         return xfa[0]*tyf[0] + xfa[1]*tyf[1] + xfa[2]*tyf[2] + xfa[3]*tyf[3];
 136 #undef f
 137                 }
 138                 break;
 139
 140
 141         case 5: // Fast Spline (non-animated)
 142                 {
 143 #define P(x)    (((x)>0)?((x)*(x)*(x)):0.0f)
 144 #define R(x)    ( P(x+2) - 4.0f*P(x+1) + 6.0f*P(x) - 4.0f*P(x-1) )*(1.0f/6.0f)
 145 #define F(i,j)  ((*this)(subseed,i+x,j+y)*(R((i)-a)*R(b-(j))))
 146 #define FT(i,j,k)       ((*this)(subseed,i+x,j+y,k+t)*(R((i)-a)*R(b-(j))*R((k)-c)))
 147 #define Z(i,j) ret+=F(i,j)
 148 #define ZT(i,j,k) ret+=FT(i,j,k)
 149 #define X(i,j)  // placeholder... To make box more symmetric
 150 #define XT(i,j,k)       // placeholder... To make box more symmetric
 151
 152                 float a(xf-x), b(yf-y);
 153
 154                 // Interpolate
 155                 float ret(F(0,0));
 156                 Z(-1,-1); Z(-1, 0); Z(-1, 1); Z(-1, 2);
 157                 Z( 0,-1); X( 0, 0); Z( 0, 1); Z( 0, 2);
 158                 Z( 1,-1); Z( 1, 0); Z( 1, 1); Z( 1, 2);
 159                 Z( 2,-1); Z( 2, 0); Z( 2, 1); Z( 2, 2);
 160
 161                 return ret;
 162         }
 163
 164         case 3: // Spline (animated)
 165                 {
 166                         float a(xf-x), b(yf-y), c(tf-t);
 167
 168                         // Interpolate
 169                         float ret(FT(0,0,0));
 170                         ZT(-1,-1,-1); ZT(-1, 0,-1); ZT(-1, 1,-1); ZT(-1, 2,-1);
 171                         ZT( 0,-1,-1); ZT( 0, 0,-1); ZT( 0, 1,-1); ZT( 0, 2,-1);
 172                         ZT( 1,-1,-1); ZT( 1, 0,-1); ZT( 1, 1,-1); ZT( 1, 2,-1);
 173                         ZT( 2,-1,-1); ZT( 2, 0,-1); ZT( 2, 1,-1); ZT( 2, 2,-1);
 174
 175                         ZT(-1,-1, 0); ZT(-1, 0, 0); ZT(-1, 1, 0); ZT(-1, 2, 0);
 176                         ZT( 0,-1, 0); XT( 0, 0, 0); ZT( 0, 1, 0); ZT( 0, 2, 0);
 177                         ZT( 1,-1, 0); ZT( 1, 0, 0); ZT( 1, 1, 0); ZT( 1, 2, 0);
 178                         ZT( 2,-1, 0); ZT( 2, 0, 0); ZT( 2, 1, 0); ZT( 2, 2, 0);
 179
 180                         ZT(-1,-1, 1); ZT(-1, 0, 1); ZT(-1, 1, 1); ZT(-1, 2, 1);
 181                         ZT( 0,-1, 1); ZT( 0, 0, 1); ZT( 0, 1, 1); ZT( 0, 2, 1);
 182                         ZT( 1,-1, 1); ZT( 1, 0, 1); ZT( 1, 1, 1); ZT( 1, 2, 1);
 183                         ZT( 2,-1, 1); ZT( 2, 0, 1); ZT( 2, 1, 1); ZT( 2, 2, 1);
 184
 185                         ZT(-1,-1, 2); ZT(-1, 0, 2); ZT(-1, 1, 2); ZT(-1, 2, 2);
 186                         ZT( 0,-1, 2); ZT( 0, 0, 2); ZT( 0, 1, 2); ZT( 0, 2, 2);
 187                         ZT( 1,-1, 2); ZT( 1, 0, 2); ZT( 1, 1, 2); ZT( 1, 2, 2);
 188                         ZT( 2,-1, 2); ZT( 2, 0, 2); ZT( 2, 1, 2); ZT( 2, 2, 2);
 189
 190                         return ret;
 191
 192 /*
 193
 194                         float dx=xf-x;
 195                         float dy=yf-y;
 196                         float dt=tf-t;
 197
 198                         float ret=0;
 199                         int i,j,h;
 200                         for(h=-1;h<=2;h++)
 201                                 for(i=-1;i<=2;i++)
 202                                         for(j=-1;j<=2;j++)
 203                                                 ret+=(*this)(subseed,i+x,j+y,h+t)*(R(i-dx)*R(j-dy)*R(h-dt));
 204                         return ret;
 205 */
 206                 }
 207                 break;
 208 #undef X
 209 #undef Z
 210 #undef F
 211 #undef P
 212 #undef R
 213
 214         case 2: // Cosine
 215         if((float)t==tf)
 216         {
 217                 int x((int)floor(xf));
 218                 int y((int)floor(yf));
 219                 float a=xf-x;
 220                 float b=yf-y;
 221                 a=(1.0f-cos(a*3.1415927))*0.5f;
 222                 b=(1.0f-cos(b*3.1415927))*0.5f;
 223                 float c=1.0-a;
 224                 float d=1.0-b;
 225                 int x2=x+1,y2=y+1;
 226                 return
 227                         (*this)(subseed,x,y,t)*(c*d)+
 228                         (*this)(subseed,x2,y,t)*(a*d)+
 229                         (*this)(subseed,x,y2,t)*(c*b)+
 230                         (*this)(subseed,x2,y2,t)*(a*b);
 231         }
 232         else
 233         {
 234                 float a=xf-x;
 235                 float b=yf-y;
 236                 float c=tf-t;
 237
 238                 a=(1.0f-cos(a*3.1415927))*0.5f;
 239                 b=(1.0f-cos(b*3.1415927))*0.5f;
 240
 241                 // We don't perform this on the time axis, otherwise we won't
 242                 // get smooth motion
 243                 //c=(1.0f-cos(c*3.1415927))*0.5f;
 244
 245                 float d=1.0-a;
 246                 float e=1.0-b;
 247                 float f=1.0-c;
 248
 249                 int x2=x+1,y2=y+1,t2=t+1;
 250
 251                 return
 252                         (*this)(subseed,x,y,t)*(d*e*f)+
 253                         (*this)(subseed,x2,y,t)*(a*e*f)+
 254                         (*this)(subseed,x,y2,t)*(d*b*f)+
 255                         (*this)(subseed,x2,y2,t)*(a*b*f)+
 256                         (*this)(subseed,x,y,t2)*(d*e*c)+
 257                         (*this)(subseed,x2,y,t2)*(a*e*c)+
 258                         (*this)(subseed,x,y2,t2)*(d*b*c)+
 259                         (*this)(subseed,x2,y2,t2)*(a*b*c);
 260         }
 261         case 1: // Linear
 262         if((float)t==tf)
 263         {
 264                 int x((int)floor(xf));
 265                 int y((int)floor(yf));
 266                 float a=xf-x;
 267                 float b=yf-y;
 268                 float c=1.0-a;
 269                 float d=1.0-b;
 270                 int x2=x+1,y2=y+1;
 271                 return
 272                         (*this)(subseed,x,y,t)*(c*d)+
 273                         (*this)(subseed,x2,y,t)*(a*d)+
 274                         (*this)(subseed,x,y2,t)*(c*b)+
 275                         (*this)(subseed,x2,y2,t)*(a*b);
 276         }
 277         else
 278         {
 279
 280                 float a=xf-x;
 281                 float b=yf-y;
 282                 float c=tf-t;
 283
 284                 float d=1.0-a;
 285                 float e=1.0-b;
 286                 float f=1.0-c;
 287
 288                 int x2=x+1,y2=y+1,t2=t+1;
 289
 290                 return
 291                         (*this)(subseed,x,y,t)*(d*e*f)+
 292                         (*this)(subseed,x2,y,t)*(a*e*f)+
 293                         (*this)(subseed,x,y2,t)*(d*b*f)+
 294                         (*this)(subseed,x2,y2,t)*(a*b*f)+
 295                         (*this)(subseed,x,y,t2)*(d*e*c)+
 296                         (*this)(subseed,x2,y,t2)*(a*e*c)+
 297                         (*this)(subseed,x,y2,t2)*(d*b*c)+
 298                         (*this)(subseed,x2,y2,t2)*(a*b*c);
 299         }
 300         default:
 301         case 0:
 302                 return (*this)(subseed,x,y,t);
 303         }
 304 }