synfig-core/trunk/src/modules/mod_noise/random.cpp

   1 /* === S Y N F I G ========================================================= */
   2 /*!     \file mod_noise/random.cpp
   3 **      \brief blehh
   4 **
   5 **      $Id$
   6 **
   7 **      \legal
   8 **      Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
   9 **      Copyright (c) 2007 Chris Moore
  10 **
  11 **      This package is free software; you can redistribute it and/or
  12 **      modify it under the terms of the GNU General Public License as
  13 **      published by the Free Software Foundation; either version 2 of
  14 **      the License, or (at your option) any later version.
  15 **
  16 **      This package is distributed in the hope that it will be useful,
  17 **      but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 **      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  19 **      General Public License for more details.
  20 **      \endlegal
  21 */
  22 /* ========================================================================= */
  23
  24 /* === H E A D E R S ======================================================= */
  25
  26 #ifdef USING_PCH
  27 #       include "pch.h"
  28 #else
  29 #ifdef HAVE_CONFIG_H
  30 #       include <config.h>
  31 #endif
  32
  33 #include "random.h"
  34 #include <synfig/quick_rng.h>
  35 #include <cmath>
  36 #include <cstdlib>
  37 #endif
  38
  39 /* === M A C R O S ========================================================= */
  40
  41 #define PI      (3.1415927)
  42
  43 /* === G L O B A L S ======================================================= */
  44
  45 /* === P R O C E D U R E S ================================================= */
  46
  47 /* === M E T H O D S ======================================================= */
  48
  49 void
  50 Random::set_seed(int x)
  51 {
  52         seed_=x;
  53 }
  54
  55 float
  56 Random::operator()(const int salt,const int x,const int y,const int t)const
  57 {
  58         static const unsigned int a(21870);
  59         static const unsigned int b(11213);
  60         static const unsigned int c(36979);
  61         static const unsigned int d(31337);
  62
  63         quick_rng rng(
  64                 ( static_cast<unsigned int>(x+y)        * a ) ^
  65                 ( static_cast<unsigned int>(y+t)        * b ) ^
  66                 ( static_cast<unsigned int>(t+x)        * c ) ^
  67                 ( static_cast<unsigned int>(seed_+salt) * d )
  68         );
  69
  70         return rng.f() * 2.0f - 1.0f;
  71 }
  72
  73 float
  74 Random::operator()(SmoothType smooth,int subseed,float xf,float yf,float tf)const
  75 {
  76         int x((int)floor(xf));
  77         int y((int)floor(yf));
  78         int t((int)floor(tf));
  79
  80         switch(smooth)
  81         {
  82         case SMOOTH_CUBIC:      // cubic
  83                 {
  84                         #define f(j,i,k)        ((*this)(subseed,i,j,k))
  85                         //Using catmull rom interpolation because it doesn't blur at all
  86                         // ( http://www.gamedev.net/reference/articles/article1497.asp )
  87                         //bezier curve with intermediate ctrl pts: 0.5/3(p(i+1) - p(i-1)) and similar
  88                         float xfa [4], tfa[4];
  89
  90                         //precalculate indices (all clamped) and offset
  91                         const int xa[] = {x-1,x,x+1,x+2};
  92
  93                         const int ya[] = {y-1,y,y+1,y+2};
  94
  95                         const int ta[] = {t-1,t,t+1,t+2};
  96
  97                         const float dx(xf-x);
  98                         const float dy(yf-y);
  99                         const float dt(tf-t);
 100
 101                         //figure polynomials for each point
 102                         const float txf[] =
 103                         {
 104                                 0.5*dx*(dx*(dx*(-1) + 2) - 1),  //-t + 2t^2 -t^3
 105                                 0.5*(dx*(dx*(3*dx - 5)) + 2),   //2 - 5t^2 + 3t^3
 106                                 0.5*dx*(dx*(-3*dx + 4) + 1),    //t + 4t^2 - 3t^3
 107                                 0.5*dx*dx*(dx-1)                                //-t^2 + t^3
 108                         };
 109
 110                         const float tyf[] =
 111                         {
 112                                 0.5*dy*(dy*(dy*(-1) + 2) - 1),  //-t + 2t^2 -t^3
 113                                 0.5*(dy*(dy*(3*dy - 5)) + 2),   //2 - 5t^2 + 3t^3
 114                                 0.5*dy*(dy*(-3*dy + 4) + 1),    //t + 4t^2 - 3t^3
 115                                 0.5*dy*dy*(dy-1)                                //-t^2 + t^3
 116                         };
 117
 118                         const float ttf[] =
 119                         {
 120                                 0.5*dt*(dt*(dt*(-1) + 2) - 1),  //-t + 2t^2 -t^3
 121                                 0.5*(dt*(dt*(3*dt - 5)) + 2),   //2 - 5t^2 + 3t^3
 122                                 0.5*dt*(dt*(-3*dt + 4) + 1),    //t + 4t^2 - 3t^3
 123                                 0.5*dt*dt*(dt-1)                                //-t^2 + t^3
 124                         };
 125
 126                         //evaluate polynomial for each row
 127                         for(int i = 0; i < 4; ++i)
 128                         {
 129                                 for(int j = 0; j < 4; ++j)
 130                                 {
 131                                         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];
 132                                 }
 133                                 xfa[i] = tfa[0]*txf[0] + tfa[1]*txf[1] + tfa[2]*txf[2] + tfa[3]*txf[3];
 134                         }
 135
 136                         //return the cumulative column evaluation
 137                         return xfa[0]*tyf[0] + xfa[1]*tyf[1] + xfa[2]*tyf[2] + xfa[3]*tyf[3];
 138 #undef f
 139                 }
 140                 break;
 141
 142
 143         case SMOOTH_FAST_SPLINE:        // Fast Spline (non-animated)
 144                 {
 145 #define P(x)    (((x)>0)?((x)*(x)*(x)):0.0f)
 146 #define R(x)    ( P(x+2) - 4.0f*P(x+1) + 6.0f*P(x) - 4.0f*P(x-1) )*(1.0f/6.0f)
 147 #define F(i,j)  ((*this)(subseed,i+x,j+y)*(R((i)-a)*R(b-(j))))
 148 #define FT(i,j,k)       ((*this)(subseed,i+x,j+y,k+t)*(R((i)-a)*R(b-(j))*R((k)-c)))
 149 #define Z(i,j) ret+=F(i,j)
 150 #define ZT(i,j,k) ret+=FT(i,j,k)
 151 #define X(i,j)  // placeholder... To make box more symmetric
 152 #define XT(i,j,k)       // placeholder... To make box more symmetric
 153
 154                 float a(xf-x), b(yf-y);
 155
 156                 // Interpolate
 157                 float ret(F(0,0));
 158                 Z(-1,-1); Z(-1, 0); Z(-1, 1); Z(-1, 2);
 159                 Z( 0,-1); X( 0, 0); Z( 0, 1); Z( 0, 2);
 160                 Z( 1,-1); Z( 1, 0); Z( 1, 1); Z( 1, 2);
 161                 Z( 2,-1); Z( 2, 0); Z( 2, 1); Z( 2, 2);
 162
 163                 return ret;
 164         }
 165
 166         case SMOOTH_SPLINE:     // Spline (animated)
 167                 {
 168                         float a(xf-x), b(yf-y), c(tf-t);
 169
 170                         // Interpolate
 171                         float ret(FT(0,0,0));
 172                         ZT(-1,-1,-1); ZT(-1, 0,-1); ZT(-1, 1,-1); ZT(-1, 2,-1);
 173                         ZT( 0,-1,-1); ZT( 0, 0,-1); ZT( 0, 1,-1); ZT( 0, 2,-1);
 174                         ZT( 1,-1,-1); ZT( 1, 0,-1); ZT( 1, 1,-1); ZT( 1, 2,-1);
 175                         ZT( 2,-1,-1); ZT( 2, 0,-1); ZT( 2, 1,-1); ZT( 2, 2,-1);
 176
 177                         ZT(-1,-1, 0); ZT(-1, 0, 0); ZT(-1, 1, 0); ZT(-1, 2, 0);
 178                         ZT( 0,-1, 0); XT( 0, 0, 0); ZT( 0, 1, 0); ZT( 0, 2, 0);
 179                         ZT( 1,-1, 0); ZT( 1, 0, 0); ZT( 1, 1, 0); ZT( 1, 2, 0);
 180                         ZT( 2,-1, 0); ZT( 2, 0, 0); ZT( 2, 1, 0); ZT( 2, 2, 0);
 181
 182                         ZT(-1,-1, 1); ZT(-1, 0, 1); ZT(-1, 1, 1); ZT(-1, 2, 1);
 183                         ZT( 0,-1, 1); ZT( 0, 0, 1); ZT( 0, 1, 1); ZT( 0, 2, 1);
 184                         ZT( 1,-1, 1); ZT( 1, 0, 1); ZT( 1, 1, 1); ZT( 1, 2, 1);
 185                         ZT( 2,-1, 1); ZT( 2, 0, 1); ZT( 2, 1, 1); ZT( 2, 2, 1);
 186
 187                         ZT(-1,-1, 2); ZT(-1, 0, 2); ZT(-1, 1, 2); ZT(-1, 2, 2);
 188                         ZT( 0,-1, 2); ZT( 0, 0, 2); ZT( 0, 1, 2); ZT( 0, 2, 2);
 189                         ZT( 1,-1, 2); ZT( 1, 0, 2); ZT( 1, 1, 2); ZT( 1, 2, 2);
 190                         ZT( 2,-1, 2); ZT( 2, 0, 2); ZT( 2, 1, 2); ZT( 2, 2, 2);
 191
 192                         return ret;
 193
 194 /*
 195
 196                         float dx=xf-x;
 197                         float dy=yf-y;
 198                         float dt=tf-t;
 199
 200                         float ret=0;
 201                         int i,j,h;
 202                         for(h=-1;h<=2;h++)
 203                                 for(i=-1;i<=2;i++)
 204                                         for(j=-1;j<=2;j++)
 205                                                 ret+=(*this)(subseed,i+x,j+y,h+t)*(R(i-dx)*R(j-dy)*R(h-dt));
 206                         return ret;
 207 */
 208                 }
 209                 break;
 210 #undef X
 211 #undef Z
 212 #undef F
 213 #undef P
 214 #undef R
 215
 216         case SMOOTH_COSINE:
 217         if((float)t==tf)
 218         {
 219                 int x((int)floor(xf));
 220                 int y((int)floor(yf));
 221                 float a=xf-x;
 222                 float b=yf-y;
 223                 a=(1.0f-cos(a*PI))*0.5f;
 224                 b=(1.0f-cos(b*PI))*0.5f;
 225                 float c=1.0-a;
 226                 float d=1.0-b;
 227                 int x2=x+1,y2=y+1;
 228                 return
 229                         (*this)(subseed,x,y,t)*(c*d)+
 230                         (*this)(subseed,x2,y,t)*(a*d)+
 231                         (*this)(subseed,x,y2,t)*(c*b)+
 232                         (*this)(subseed,x2,y2,t)*(a*b);
 233         }
 234         else
 235         {
 236                 float a=xf-x;
 237                 float b=yf-y;
 238                 float c=tf-t;
 239
 240                 a=(1.0f-cos(a*PI))*0.5f;
 241                 b=(1.0f-cos(b*PI))*0.5f;
 242
 243                 // We don't perform this on the time axis, otherwise we won't
 244                 // get smooth motion
 245                 //c=(1.0f-cos(c*PI))*0.5f;
 246
 247                 float d=1.0-a;
 248                 float e=1.0-b;
 249                 float f=1.0-c;
 250
 251                 int x2=x+1,y2=y+1,t2=t+1;
 252
 253                 return
 254                         (*this)(subseed,x,y,t)*(d*e*f)+
 255                         (*this)(subseed,x2,y,t)*(a*e*f)+
 256                         (*this)(subseed,x,y2,t)*(d*b*f)+
 257                         (*this)(subseed,x2,y2,t)*(a*b*f)+
 258                         (*this)(subseed,x,y,t2)*(d*e*c)+
 259                         (*this)(subseed,x2,y,t2)*(a*e*c)+
 260                         (*this)(subseed,x,y2,t2)*(d*b*c)+
 261                         (*this)(subseed,x2,y2,t2)*(a*b*c);
 262         }
 263         case SMOOTH_LINEAR:
 264         if((float)t==tf)
 265         {
 266                 int x((int)floor(xf));
 267                 int y((int)floor(yf));
 268                 float a=xf-x;
 269                 float b=yf-y;
 270                 float c=1.0-a;
 271                 float d=1.0-b;
 272                 int x2=x+1,y2=y+1;
 273                 return
 274                         (*this)(subseed,x,y,t)*(c*d)+
 275                         (*this)(subseed,x2,y,t)*(a*d)+
 276                         (*this)(subseed,x,y2,t)*(c*b)+
 277                         (*this)(subseed,x2,y2,t)*(a*b);
 278         }
 279         else
 280         {
 281
 282                 float a=xf-x;
 283                 float b=yf-y;
 284                 float c=tf-t;
 285
 286                 float d=1.0-a;
 287                 float e=1.0-b;
 288                 float f=1.0-c;
 289
 290                 int x2=x+1,y2=y+1,t2=t+1;
 291
 292                 return
 293                         (*this)(subseed,x,y,t)*(d*e*f)+
 294                         (*this)(subseed,x2,y,t)*(a*e*f)+
 295                         (*this)(subseed,x,y2,t)*(d*b*f)+
 296                         (*this)(subseed,x2,y2,t)*(a*b*f)+
 297                         (*this)(subseed,x,y,t2)*(d*e*c)+
 298                         (*this)(subseed,x2,y,t2)*(a*e*c)+
 299                         (*this)(subseed,x,y2,t2)*(d*b*c)+
 300                         (*this)(subseed,x2,y2,t2)*(a*b*c);
 301         }
 302         default:
 303         case SMOOTH_DEFAULT:
 304                 return (*this)(subseed,x,y,t);
 305         }
 306 }