/* Emacs style mode select -*- C++ -*- *----------------------------------------------------------------------------- * * * PrBoom a Doom port merged with LxDoom and LSDLDoom * based on BOOM, a modified and improved DOOM engine * Copyright (C) 1999 by * id Software, Chi Hoang, Lee Killough, Jim Flynn, Rand Phares, Ty Halderman * Copyright (C) 1999-2000 by * Jess Haas, Nicolas Kalkhof, Colin Phipps, Florian Schulze * * This program 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 program 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. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA * 02111-1307, USA. * * DESCRIPTION: * Random number LUT. * * 1/19/98 killough: Rewrote random number generator for better randomness, * while at the same time maintaining demo sync and backward compatibility. * * 2/16/98 killough: Made each RNG local to each control-equivalent block, * to reduce the chances of demo sync problems. * *-----------------------------------------------------------------------------*/ #include "doomstat.h" #include "m_random.h" // // M_Random // Returns a 0-255 number // static const unsigned char rndtable[256] = { // 1/19/98 killough -- made const 0, 8, 109, 220, 222, 241, 149, 107, 75, 248, 254, 140, 16, 66 , 74, 21, 211, 47, 80, 242, 154, 27, 205, 128, 161, 89, 77, 36 , 95, 110, 85, 48, 212, 140, 211, 249, 22, 79, 200, 50, 28, 188 , 52, 140, 202, 120, 68, 145, 62, 70, 184, 190, 91, 197, 152, 224 , 149, 104, 25, 178, 252, 182, 202, 182, 141, 197, 4, 81, 181, 242 , 145, 42, 39, 227, 156, 198, 225, 193, 219, 93, 122, 175, 249, 0 , 175, 143, 70, 239, 46, 246, 163, 53, 163, 109, 168, 135, 2, 235 , 25, 92, 20, 145, 138, 77, 69, 166, 78, 176, 173, 212, 166, 113 , 94, 161, 41, 50, 239, 49, 111, 164, 70, 60, 2, 37, 171, 75 , 136, 156, 11, 56, 42, 146, 138, 229, 73, 146, 77, 61, 98, 196 , 135, 106, 63, 197, 195, 86, 96, 203, 113, 101, 170, 247, 181, 113 , 80, 250, 108, 7, 255, 237, 129, 226, 79, 107, 112, 166, 103, 241 , 24, 223, 239, 120, 198, 58, 60, 82, 128, 3, 184, 66, 143, 224 , 145, 224, 81, 206, 163, 45, 63, 90, 168, 114, 59, 33, 159, 95 , 28, 139, 123, 98, 125, 196, 15, 70, 194, 253, 54, 14, 109, 226 , 71, 17, 161, 93, 186, 87, 244, 138, 20, 52, 123, 251, 26, 36 , 17, 46, 52, 231, 232, 76, 31, 221, 84, 37, 216, 165, 212, 106 , 197, 242, 98, 43, 39, 175, 254, 145, 190, 84, 118, 222, 187, 136 , 120, 163, 236, 249 }; rng_t rng; // the random number state unsigned long rngseed = 1993; // killough 3/26/98: The seed int P_Random(pr_class_t pr_class) { // killough 2/16/98: We always update both sets of random number // generators, to ensure repeatability if the demo_compatibility // flag is changed while the program is running. Changing the // demo_compatibility flag does not change the sequences generated, // only which one is selected from. // // All of this RNG stuff is tricky as far as demo sync goes -- // it's like playing with explosives :) Lee int compat = pr_class == pr_misc ? (rng.prndindex = (rng.prndindex + 1) & 255) : (rng. rndindex = (rng. rndindex + 1) & 255) ; unsigned long boom; // killough 3/31/98: // If demo sync insurance is not requested, use // much more unstable method by putting everything // except pr_misc into pr_all_in_one if (pr_class != pr_misc && !demo_insurance) // killough 3/31/98 pr_class = pr_all_in_one; boom = rng.seed[pr_class]; // killough 3/26/98: add pr_class*2 to addend rng.seed[pr_class] = boom * 1664525ul + 221297ul + pr_class*2; if (demo_compatibility) return rndtable[compat]; boom >>= 20; /* killough 3/30/98: use gametic-levelstarttic to shuffle RNG * killough 3/31/98: but only if demo insurance requested, * since it's unnecessary for random shuffling otherwise * killough 9/29/98: but use basetic now instead of levelstarttic * cph - DEMOSYNC - this change makes MBF demos work, * but does it break Boom ones? */ if (demo_insurance) boom += (gametic-basetic)*7; return boom & 255; } // Initialize all the seeds // // This initialization method is critical to maintaining demo sync. // Each seed is initialized according to its class, so if new classes // are added they must be added to end of pr_class_t list. killough // void M_ClearRandom (void) { int i; unsigned long seed = rngseed*2+1; // add 3/26/98: add rngseed for (i=0; i65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 
/*
** FFT and FHT routines
**  Copyright 1988, 1993; Ron Mayer
**  
**  mayer_fht(fz,n);
**      Does a hartley transform of "n" points in the array "fz".
**  mayer_fft(n,real,imag)
**      Does a fourier transform of "n" points of the "real" and
**      "imag" arrays.
**  mayer_ifft(n,real,imag)
**      Does an inverse fourier transform of "n" points of the "real"
**      and "imag" arrays.
**  mayer_realfft(n,real)
**      Does a real-valued fourier transform of "n" points of the
**      "real" array.  The real part of the transform ends
**      up in the first half of the array and the imaginary part of the
**      transform ends up in the second half of the array.
**  mayer_realifft(n,real)
**      The inverse of the realfft() routine above.
**      
**      
** NOTE: This routine uses at least 2 patented algorithms, and may be
**       under the restrictions of a bunch of different organizations.
**       Although I wrote it completely myself, it is kind of a derivative
**       of a routine I once authored and released under the GPL, so it
**       may fall under the free software foundation's restrictions;
**       it was worked on as a Stanford Univ project, so they claim
**       some rights to it; it was further optimized at work here, so
**       I think this company claims parts of it.  The patents are
**       held by R. Bracewell (the FHT algorithm) and O. Buneman (the
**       trig generator), both at Stanford Univ.
**       If it were up to me, I'd say go do whatever you want with it;
**       but it would be polite to give credit to the following people
**       if you use this anywhere:
**           Euler     - probable inventor of the fourier transform.
**           Gauss     - probable inventor of the FFT.
**           Hartley   - probable inventor of the hartley transform.
**           Buneman   - for a really cool trig generator
**           Mayer(me) - for authoring this particular version and
**                       including all the optimizations in one package.
**       Thanks,
**       Ron Mayer; mayer@acuson.com
**
*/

/* This is a slightly modified version of Mayer's contribution; write
* msp@ucsd.edu for the original code.  Kudos to Mayer for a fine piece
* of work.  -msp
*/

#ifdef MSW
#pragma warning( disable : 4305 )  /* uncast const double to float */
#pragma warning( disable : 4244 )  /* uncast double to float */
#pragma warning( disable : 4101 )  /* unused local variables */
#endif

#define REAL float
#define GOOD_TRIG

#ifdef GOOD_TRIG
#else
#define FAST_TRIG
#endif

#if defined(GOOD_TRIG)
#define FHT_SWAP(a,b,t) {(t)=(a);(a)=(b);(b)=(t);}
#define TRIG_VARS					         \
      int t_lam=0;
#define TRIG_INIT(k,c,s)					 \
     {								 \
      int i;							 \
      for (i=2 ; i<=k ; i++)					 \
          {coswrk[i]=costab[i];sinwrk[i]=sintab[i];}		 \
      t_lam = 0;					         \
      c = 1;							 \
      s = 0;							 \
     }
#define TRIG_NEXT(k,c,s)					 \
     {								 \
	 int i,j;	                                         \
         (t_lam)++;	  					 \
         for (i=0 ; !((1<<i)&t_lam) ; i++);			 \
         i = k-i;						 \
         s = sinwrk[i];						 \
         c = coswrk[i];						 \
         if (i>1)   						 \
            {	    						 \
             for (j=k-i+2 ; (1<<j)&t_lam ; j++);		 \
             j	       = k - j;					 \
             sinwrk[i] = halsec[i] * (sinwrk[i-1] + sinwrk[j]);  \
             coswrk[i] = halsec[i] * (coswrk[i-1] + coswrk[j]);  \
            }                                                    \
     }
#define TRIG_RESET(k,c,s)
#endif

#if defined(FAST_TRIG)
#define TRIG_VARS					 \
      REAL t_c,t_s;
#define TRIG_INIT(k,c,s)				 \
    {				        		 \
     t_c  = costab[k];				         \
     t_s  = sintab[k];				         \
     c    = 1;				    		 \
     s    = 0;				    		 \
    }
#define TRIG_NEXT(k,c,s)				 \
    {                                                    \
     REAL t = c;                                         \
     c   = t*t_c - s*t_s;				 \
     s   = t*t_s + s*t_c;				 \
    }
#define TRIG_RESET(k,c,s)
#endif

static REAL halsec[20]=
    {
     0,
     0,
     .54119610014619698439972320536638942006107206337801,
     .50979557910415916894193980398784391368261849190893,
     .50241928618815570551167011928012092247859337193963,
     .50060299823519630134550410676638239611758632599591,
     .50015063602065098821477101271097658495974913010340,
     .50003765191554772296778139077905492847503165398345,
     .50000941253588775676512870469186533538523133757983,
     .50000235310628608051401267171204408939326297376426,
     .50000058827484117879868526730916804925780637276181,
     .50000014706860214875463798283871198206179118093251,
     .50000003676714377807315864400643020315103490883972,
     .50000000919178552207366560348853455333939112569380,
     .50000000229794635411562887767906868558991922348920,
     .50000000057448658687873302235147272458812263401372
    };
static REAL costab[20]=
    {
     .00000000000000000000000000000000000000000000000000,
     .70710678118654752440084436210484903928483593768847,
     .92387953251128675612818318939678828682241662586364,
     .98078528040323044912618223613423903697393373089333,
     .99518472667219688624483695310947992157547486872985,
     .99879545620517239271477160475910069444320361470461,
     .99969881869620422011576564966617219685006108125772,
     .99992470183914454092164649119638322435060646880221,
     .99998117528260114265699043772856771617391725094433,
     .99999529380957617151158012570011989955298763362218,
     .99999882345170190992902571017152601904826792288976,
     .99999970586288221916022821773876567711626389934930,
     .99999992646571785114473148070738785694820115568892,
     .99999998161642929380834691540290971450507605124278,
     .99999999540410731289097193313960614895889430318945,
     .99999999885102682756267330779455410840053741619428
    };
static REAL sintab[20]=
    {
     1.0000000000000000000000000000000000000000000000000,
     .70710678118654752440084436210484903928483593768846,
     .38268343236508977172845998403039886676134456248561,
     .19509032201612826784828486847702224092769161775195,
     .09801714032956060199419556388864184586113667316749,
     .04906767432741801425495497694268265831474536302574,
     .02454122852291228803173452945928292506546611923944,
     .01227153828571992607940826195100321214037231959176,
     .00613588464915447535964023459037258091705788631738,
     .00306795676296597627014536549091984251894461021344,
     .00153398018628476561230369715026407907995486457522,
     .00076699031874270452693856835794857664314091945205,
     .00038349518757139558907246168118138126339502603495,
     .00019174759731070330743990956198900093346887403385,
     .00009587379909597734587051721097647635118706561284,
     .00004793689960306688454900399049465887274686668768
    };
static REAL coswrk[20]=
    {
     .00000000000000000000000000000000000000000000000000,
     .70710678118654752440084436210484903928483593768847,
     .92387953251128675612818318939678828682241662586364,
     .98078528040323044912618223613423903697393373089333,
     .99518472667219688624483695310947992157547486872985,
     .99879545620517239271477160475910069444320361470461,
     .99969881869620422011576564966617219685006108125772,
     .99992470183914454092164649119638322435060646880221,
     .99998117528260114265699043772856771617391725094433,
     .99999529380957617151158012570011989955298763362218,
     .99999882345170190992902571017152601904826792288976,
     .99999970586288221916022821773876567711626389934930,
     .99999992646571785114473148070738785694820115568892,
     .99999998161642929380834691540290971450507605124278,
     .99999999540410731289097193313960614895889430318945,
     .99999999885102682756267330779455410840053741619428
    };
static REAL sinwrk[20]=
    {
     1.0000000000000000000000000000000000000000000000000,
     .70710678118654752440084436210484903928483593768846,
     .38268343236508977172845998403039886676134456248561,
     .19509032201612826784828486847702224092769161775195,
     .09801714032956060199419556388864184586113667316749,
     .04906767432741801425495497694268265831474536302574,
     .02454122852291228803173452945928292506546611923944,
     .01227153828571992607940826195100321214037231959176,
     .00613588464915447535964023459037258091705788631738,
     .00306795676296597627014536549091984251894461021344,
     .00153398018628476561230369715026407907995486457522,
     .00076699031874270452693856835794857664314091945205,
     .00038349518757139558907246168118138126339502603495,
     .00019174759731070330743990956198900093346887403385,
     .00009587379909597734587051721097647635118706561284,
     .00004793689960306688454900399049465887274686668768
    };


#define SQRT2_2   0.70710678118654752440084436210484
#define SQRT2   2*0.70710678118654752440084436210484

void mayer_fht(REAL *fz, int n)
{
/*  REAL a,b;
REAL c1,s1,s2,c2,s3,c3,s4,c4;
 REAL f0,g0,f1,g1,f2,g2,f3,g3; */
 int  k,k1,k2,k3,k4,kx;
 REAL *fi,*fn,*gi;
 TRIG_VARS;

 for (k1=1,k2=0;k1<n;k1++)
    {
     REAL aa;
     for (k=n>>1; (!((k2^=k)&k)); k>>=1);
     if (k1>k2)
	{
	     aa=fz[k1];fz[k1]=fz[k2];fz[k2]=aa;
	}
    }
 for ( k=0 ; (1<<k)<n ; k++ );
 k  &= 1;
 if (k==0)
    {
	 for (fi=fz,fn=fz+n;fi<fn;fi+=4)
	    {
	     REAL f0,f1,f2,f3;
	     f1     = fi[0 ]-fi[1 ];
	     f0     = fi[0 ]+fi[1 ];
	     f3     = fi[2 ]-fi[3 ];
	     f2     = fi[2 ]+fi[3 ];
	     fi[2 ] = (f0-f2);	
	     fi[0 ] = (f0+f2);
	     fi[3 ] = (f1-f3);	
	     fi[1 ] = (f1+f3);
	    }
    }
 else
    {
	 for (fi=fz,fn=fz+n,gi=fi+1;fi<fn;fi+=8,gi+=8)
	    {
	     REAL bs1,bc1,bs2,bc2,bs3,bc3,bs4,bc4,
	     	bg0,bf0,bf1,bg1,bf2,bg2,bf3,bg3;
	     bc1     = fi[0 ] - gi[0 ];
	     bs1     = fi[0 ] + gi[0 ];
	     bc2     = fi[2 ] - gi[2 ];
	     bs2     = fi[2 ] + gi[2 ];
	     bc3     = fi[4 ] - gi[4 ];
	     bs3     = fi[4 ] + gi[4 ];
	     bc4     = fi[6 ] - gi[6 ];
	     bs4     = fi[6 ] + gi[6 ];
	     bf1     = (bs1 - bs2);	
	     bf0     = (bs1 + bs2);
	     bg1     = (bc1 - bc2);	
	     bg0     = (bc1 + bc2);
	     bf3     = (bs3 - bs4);	
	     bf2     = (bs3 + bs4);
	     bg3     = SQRT2*bc4;		
	     bg2     = SQRT2*bc3;
	     fi[4 ] = bf0 - bf2;
	     fi[0 ] = bf0 + bf2;
	     fi[6 ] = bf1 - bf3;
	     fi[2 ] = bf1 + bf3;
	     gi[4 ] = bg0 - bg2;
	     gi[0 ] = bg0 + bg2;
	     gi[6 ] = bg1 - bg3;
	     gi[2 ] = bg1 + bg3;
	    }
    }
 if (n<16) return;

 do
    {
     REAL s1,c1;
     int ii;
     k  += 2;
     k1  = 1  << k;
     k2  = k1 << 1;
     k4  = k2 << 1;
     k3  = k2 + k1;
     kx  = k1 >> 1;
	 fi  = fz;
	 gi  = fi + kx;
	 fn  = fz + n;
	 do
	    {
	     REAL g0,f0,f1,g1,f2,g2,f3,g3;
	     f1      = fi[0 ] - fi[k1];
	     f0      = fi[0 ] + fi[k1];
	     f3      = fi[k2] - fi[k3];
	     f2      = fi[k2] + fi[k3];
	     fi[k2]  = f0	  - f2;
	     fi[0 ]  = f0	  + f2;
	     fi[k3]  = f1	  - f3;
	     fi[k1]  = f1	  + f3;
	     g1      = gi[0 ] - gi[k1];
	     g0      = gi[0 ] + gi[k1];
	     g3      = SQRT2  * gi[k3];
	     g2      = SQRT2  * gi[k2];
	     gi[k2]  = g0	  - g2;
	     gi[0 ]  = g0	  + g2;
	     gi[k3]  = g1	  - g3;
	     gi[k1]  = g1	  + g3;
	     gi     += k4;
	     fi     += k4;
	    } while (fi<fn);
     TRIG_INIT(k,c1,s1);
     for (ii=1;ii<kx;ii++)
        {
	 REAL c2,s2;
         TRIG_NEXT(k,c1,s1);
         c2 = c1*c1 - s1*s1;
         s2 = 2*(c1*s1);
	     fn = fz + n;
	     fi = fz +ii;
	     gi = fz +k1-ii;
	     do
		{
		 REAL a,b,g0,f0,f1,g1,f2,g2,f3,g3;
		 b       = s2*fi[k1] - c2*gi[k1];
		 a       = c2*fi[k1] + s2*gi[k1];
		 f1      = fi[0 ]    - a;
		 f0      = fi[0 ]    + a;
		 g1      = gi[0 ]    - b;
		 g0      = gi[0 ]    + b;
		 b       = s2*fi[k3] - c2*gi[k3];
		 a       = c2*fi[k3] + s2*gi[k3];
		 f3      = fi[k2]    - a;
		 f2      = fi[k2]    + a;
		 g3      = gi[k2]    - b;
		 g2      = gi[k2]    + b;
		 b       = s1*f2     - c1*g3;
		 a       = c1*f2     + s1*g3;
		 fi[k2]  = f0        - a;
		 fi[0 ]  = f0        + a;
		 gi[k3]  = g1        - b;
		 gi[k1]  = g1        + b;
		 b       = c1*g2     - s1*f3;
		 a       = s1*g2     + c1*f3;
		 gi[k2]  = g0        - a;
		 gi[0 ]  = g0        + a;
		 fi[k3]  = f1        - b;
		 fi[k1]  = f1        + b;
		 gi     += k4;
		 fi     += k4;
		} while (fi<fn);
        }
     TRIG_RESET(k,c1,s1);
    } while (k4<n);
}

void mayer_fft(int n, REAL *real, REAL *imag)
{
 REAL a,b,c,d;
 REAL q,r,s,t;
 int i,j,k;
 for (i=1,j=n-1,k=n/2;i<k;i++,j--) {
  a = real[i]; b = real[j];  q=a+b; r=a-b;
  c = imag[i]; d = imag[j];  s=c+d; t=c-d;
  real[i] = (q+t)*.5; real[j] = (q-t)*.5;
  imag[i] = (s-r)*.5; imag[j] = (s+r)*.5;
 }
 mayer_fht(real,n);
 mayer_fht(imag,n);
}

void mayer_ifft(int n, REAL *real, REAL *imag)
{
 REAL a,b,c,d;
 REAL q,r,s,t;
 int i,j,k;
 mayer_fht(real,n);
 mayer_fht(imag,n);
 for (i=1,j=n-1,k=n/2;i<k;i++,j--) {
  a = real[i]; b = real[j];  q=a+b; r=a-b;
  c = imag[i]; d = imag[j];  s=c+d; t=c-d;
  imag[i] = (s+r)*0.5;  imag[j] = (s-r)*0.5;
  real[i] = (q-t)*0.5;  real[j] = (q+t)*0.5;
 }
}

void mayer_realfft(int n, REAL *real)
{
#ifdef ROCKBOX
 REAL a,b;
#else
 REAL a,b,c,d;
#endif
 int i,j,k;
 mayer_fht(real,n);
 for (i=1,j=n-1,k=n/2;i<k;i++,j--) {
  a = real[i];
  b = real[j];
  real[j] = (a-b)*0.5;
  real[i] = (a+b)*0.5;
 }
}

void mayer_realifft(int n, REAL *real)
{
#ifdef ROCKBOX
 REAL a,b;
#else
 REAL a,b,c,d;
#endif
 int i,j,k;
 for (i=1,j=n-1,k=n/2;i<k;i++,j--) {
  a = real[i];
  b = real[j];
  real[j] = (a-b);
  real[i] = (a+b);
 }
 mayer_fht(real,n);
}
generated by cgit v1.1 at 2026-05-12 09:15:24 +0000