forked from minexew/Shrine
-
Notifications
You must be signed in to change notification settings - Fork 0
/
AMathODE.HC
688 lines (631 loc) · 17.2 KB
/
AMathODE.HC
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
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
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
#help_index "Math/ODE"
#help_file "::/Doc/ODE"
//See $LK,"::/Doc/Credits.DD"$.
F64 LowPass1(F64 a,F64 y0,F64 y,F64 dt=1.0)
{//First order low pass filter
dt=Exp(-a*dt);
return y0*dt+y*(1.0-dt);
}
U0 ODERstPtrs(CMathODE *ode)
{
I64 s=ode->n_internal*sizeof(F64);
F64 *ptr=ode->array_base;
ode->state_internal=ptr; ptr(I64)+=s;
ode->state_scale=ptr; ptr(I64)+=s;
ode->DstateDt=ptr; ptr(I64)+=s;
ode->initial_state=ptr; ptr(I64)+=s;
ode->tmp0=ptr; ptr(I64)+=s;
ode->tmp1=ptr; ptr(I64)+=s;
ode->tmp2=ptr; ptr(I64)+=s;
ode->tmp3=ptr; ptr(I64)+=s;
ode->tmp4=ptr; ptr(I64)+=s;
ode->tmp5=ptr; ptr(I64)+=s;
ode->tmp6=ptr; ptr(I64)+=s;
ode->tmp7=ptr;
}
public CMathODE *ODENew(I64 n,F64 max_tolerance=1e-6,I64 flags=0)
{//Make differential equation ctrl struct. See $LK,"flags",A="MN:ODEF_HAS_MASSES"$.
//The tolerance is not precise.
//You can min_tolerance and it will
//dynamically adjust tolerance to utilize
//the CPU.
I64 s=n*sizeof(F64);
CMathODE *ode=CAlloc(sizeof(CMathODE));
ode->t_scale=1.0;
ode->flags=flags;
ode->n_internal=ode->n=n;
ode->h=1e-6;
ode->h_min=1e-64;
ode->h_max=1e32;
ode->max_tolerance=ode->min_tolerance=ode->tolerance_internal=max_tolerance;
ode->win_task=ode->mem_task=Fs;
QueInit(&ode->next_mass);
QueInit(&ode->next_spring);
ode->state=CAlloc(s);
ode->array_base=MAlloc(12*s);
ODERstPtrs(ode);
return ode;
}
public Bool ODEPause(CMathODE *ode,Bool val=ON)
{//Pause ODE.
Bool res;
if (!ode) return OFF;
res=LBEqu(&ode->flags,ODEf_PAUSED,val);
if (val)
while (Bt(&ode->flags,ODEf_BUSY))
Yield;
return res;
}
public U0 ODEDel(CMathODE *ode)
{//Free ODE node, but not masses or springs.
I64 i;
if (!ode) return;
ODEPause(ode);
Free(ode->state);
Free(ode->array_base);
if (ode->slave_tasks) {
for (i=0;i<mp_cnt;i++)
Kill(ode->slave_tasks[i]);
Free(ode->slave_tasks);
}
Free(ode);
}
public I64 ODESize(CMathODE *ode)
{//Mem size of ode ctrl, but not masses and springs.
if (!ode)
return 0;
else
return MSize2(ode->state)+MSize2(ode->array_base)+MSize2(ode);
}
U0 ODESetMassesPtrs(CMathODE *ode,F64 *state,F64 *DstateDt)
{
COrder2D3 *ptr1=state(F64 *)+ode->n,
*ptr2=DstateDt(F64 *)+ode->n;
CMass *tmpm=ode->next_mass;
while (tmpm!=&ode->next_mass) {
tmpm->state=ptr1++;
tmpm->DstateDt=ptr2++;
tmpm=tmpm->next;
}
}
U0 ODEState2Internal(CMathODE *ode)
{
CMass *tmpm;
F64 *old_array_base;
I64 mass_cnt;
if (ode->flags&ODEF_HAS_MASSES) {
mass_cnt=0;
tmpm=ode->next_mass;
while (tmpm!=&ode->next_mass) {
mass_cnt++;
tmpm=tmpm->next;
}
old_array_base=ode->array_base;
ode->n_internal=ode->n+6*mass_cnt;
ode->array_base=MAlloc(12*ode->n_internal*sizeof(F64),ode->mem_task);
Free(old_array_base);
ODERstPtrs(ode);
ODESetMassesPtrs(ode,ode->state_internal,ode->state_internal);
tmpm=ode->next_mass;
while (tmpm!=&ode->next_mass) {
MemCpy(tmpm->state,&tmpm->saved_state,sizeof(COrder2D3));
tmpm=tmpm->next;
}
}
MemCpy(ode->state_internal,ode->state,ode->n*sizeof(F64));
}
U0 ODEInternal2State(CMathODE *ode)
{
CMass *tmpm;
MemCpy(ode->state,ode->state_internal,ode->n*sizeof(F64));
if (ode->flags&ODEF_HAS_MASSES) {
ODESetMassesPtrs(ode,ode->state_internal,ode->state_internal);
tmpm=ode->next_mass;
while (tmpm!=&ode->next_mass) {
MemCpy(&tmpm->saved_state,tmpm->state,sizeof(COrder2D3));
tmpm=tmpm->next;
}
}
}
public U0 ODERenum(CMathODE *ode)
{//Renumber masses and springs.
I64 i;
CSpring *tmps;
CMass *tmpm;
i=0;
tmpm=ode->next_mass;
while (tmpm!=&ode->next_mass) {
tmpm->num=i++;
tmpm=tmpm->next;
}
i=0;
tmps=ode->next_spring;
while (tmps!=&ode->next_spring) {
tmps->num=i++;
tmps->end1_num=tmps->end1->num;
tmps->end2_num=tmps->end2->num;
tmps=tmps->next;
}
}
public CMass *MassFind(CMathODE *ode,F64 x,F64 y,F64 z=0)
{//Search for mass nearest to x,y,z.
CMass *tmpm,*best_mass=NULL;
F64 dd,best_dd=F64_MAX;
tmpm=ode->next_mass;
while (tmpm!=&ode->next_mass) {
dd=Sqr(tmpm->x-x)+Sqr(tmpm->y-y)+Sqr(tmpm->z-z);
if (dd<best_dd) {
best_dd=dd;
best_mass=tmpm;
}
tmpm=tmpm->next;
}
return best_mass;
}
public CSpring *SpringFind(CMathODE *ode,F64 x,F64 y,F64 z=0)
{//Find spring midpoint nearest x,y,z.
CSpring *tmps,*best_spring=NULL;
F64 dd,best_dd=F64_MAX;
tmps=ode->next_spring;
while (tmps!=&ode->next_spring) {
dd=Sqr((tmps->end1->x+tmps->end2->x)/2-x)+
Sqr((tmps->end1->y+tmps->end2->y)/2-y)+
Sqr((tmps->end1->z+tmps->end2->z)/2-z);
if (dd<best_dd) {
best_dd=dd;
best_spring=tmps;
}
tmps=tmps->next;
}
return best_spring;
}
public U0 MassOrSpringFind(
CMathODE *ode,CMass **res_mass,CSpring **res_spring,
F64 x,F64 y,F64 z=0)
{//Find spring or mass nearest x,y,z.
CMass *tmpm,*best_mass=NULL;
CSpring *tmps,*best_spring=NULL;
F64 dd,best_dd=F64_MAX;
tmpm=ode->next_mass;
while (tmpm!=&ode->next_mass) {
dd=Sqr(tmpm->x-x)+Sqr(tmpm->y-y)+Sqr(tmpm->z-z);
if (dd<best_dd) {
best_dd=dd;
best_mass=tmpm;
}
tmpm=tmpm->next;
}
tmps=ode->next_spring;
while (tmps!=&ode->next_spring) {
dd=Sqr((tmps->end1->x+tmps->end2->x)/2-x)+
Sqr((tmps->end1->y+tmps->end2->y)/2-y)+
Sqr((tmps->end1->z+tmps->end2->z)/2-z);
if (dd<best_dd) {
best_dd=dd;
best_spring=tmps;
best_mass=NULL;
}
tmps=tmps->next;
}
if (res_mass) *res_mass =best_mass;
if (res_spring) *res_spring=best_spring;
}
public CMass *MassFindNum(CMathODE *ode,I64 num)
{//Return mass number N.
CMass *tmpm=ode->next_mass;
while (tmpm!=&ode->next_mass) {
if (tmpm->num==num)
return tmpm;
tmpm=tmpm->next;
}
return NULL;
}
public U0 ODERstInactive(CMathODE *ode)
{//Set all masses and springs to ACTIVE for new trial.
CMass *tmpm;
CSpring *tmps;
tmpm=ode->next_mass;
while (tmpm!=&ode->next_mass) {
tmpm->flags&=~MSF_INACTIVE;
tmpm=tmpm->next;
}
tmps=ode->next_spring;
while (tmps!=&ode->next_spring) {
tmps->flags&=~SSF_INACTIVE;
tmps=tmps->next;
}
}
U0 ODECalcSprings(CMathODE *ode)
{
CSpring *tmps=ode->next_spring;
CMass *e1,*e2;
F64 d;
CD3 p;
while (tmps!=&ode->next_spring) {
if (tmps->flags&SSF_INACTIVE) {
tmps->displacement=0;
tmps->f=0;
} else {
e1=tmps->end1;
e2=tmps->end2;
d=D3Norm(D3Sub(&p,&e2->state->x,&e1->state->x));
tmps->displacement=d-tmps->rest_len;
tmps->f=tmps->displacement*tmps->const;
if (tmps->f>0 && tmps->flags&SSF_NO_TENSION)
tmps->f=0;
else if (tmps->f<0 && tmps->flags&SSF_NO_COMPRESSION)
tmps->f=0;
if (d>0) {
D3MulEqu(&p,tmps->f/d);
D3AddEqu(&e1->DstateDt->DxDt,&p);
D3SubEqu(&e2->DstateDt->DxDt,&p);
}
}
tmps=tmps->next;
}
}
U0 ODECalcDrag(CMathODE *ode)
{
CMass *tmpm;
F64 d,dd;
CD3 p;
if (ode->drag_v || ode->drag_v2 || ode->drag_v3) {
tmpm=ode->next_mass;
while (tmpm!=&ode->next_mass) {
if (!(tmpm->flags & MSF_INACTIVE) &&
tmpm->drag_profile_factor &&
(dd=D3NormSqr(&tmpm->state->DxDt))) {
d=ode->drag_v;
if (ode->drag_v2)
d+=ode->drag_v2*Sqrt(dd);
if (ode->drag_v3)
d+=dd*ode->drag_v3;
D3SubEqu(&tmpm->DstateDt->DxDt,
D3Mul(&p,d*tmpm->drag_profile_factor,&tmpm->state->DxDt));
}
tmpm=tmpm->next;
}
}
}
U0 ODEApplyAccelerationLimit(CMathODE *ode)
{
CMass *tmpm;
F64 d;
if (ode->acceleration_limit) {
tmpm=ode->next_mass;
while (tmpm!=&ode->next_mass) {
if (!(tmpm->flags & MSF_INACTIVE) &&
(d=D3Norm(&tmpm->DstateDt->DxDt))>ode->acceleration_limit)
D3MulEqu(&tmpm->DstateDt->DxDt,ode->acceleration_limit/d);
tmpm=tmpm->next;
}
}
}
U0 ODEMPTask(CMathODE *ode)
{
while (TRUE) {
while (!Bt(&ode->mp_not_done_flags,Gs->num))
Yield;
if (ode->mp_derive)
(*ode->mp_derive)(ode,ode->mp_t,
Gs->num,ode->mp_state,ode->mp_DstateDt);
LBtr(&ode->mp_not_done_flags,Gs->num);
}
}
U0 ODEMPWake(CMathODE *ode)
{
I64 i;
if (!ode->slave_tasks) {
ode->slave_tasks=CAlloc(mp_cnt*sizeof(CTask *));
for (i=0;i<mp_cnt;i++)
ode->slave_tasks[i]=Spawn(&ODEMPTask,ode,"ODE Slave",i);
}
for (i=0;i<mp_cnt;i++) {
Suspend(ode->slave_tasks[i],FALSE);
MPInt(I_WAKE,i);
}
}
U0 ODEMPSleep(CMathODE *ode)
{
I64 i;
if (ode->slave_tasks) {
while (ode->mp_not_done_flags)
Yield;
for (i=0;i<mp_cnt;i++)
Suspend(ode->slave_tasks[i]);
}
}
U0 ODECallMPDerivative(CMathODE *ode,F64 t,F64 *state,F64 *DstateDt)
{
ode->mp_t=t;
ode->mp_state=state;
ode->mp_DstateDt=DstateDt;
ode->mp_not_done_flags=1<<mp_cnt-1;
do Yield;
while (ode->mp_not_done_flags);
}
U0 ODECallDerivative(CMathODE *ode,F64 t,F64 *state,F64 *DstateDt)
{
CMass *tmpm;
if (ode->flags&ODEF_HAS_MASSES) {
ODESetMassesPtrs(ode,state,DstateDt);
tmpm=ode->next_mass;
while (tmpm!=&ode->next_mass) {
if (!(tmpm->flags&MSF_INACTIVE)) {
D3Zero(&tmpm->DstateDt->DxDt);
D3Copy(&tmpm->DstateDt->x,&tmpm->state->DxDt);
}
tmpm=tmpm->next;
}
ODECalcSprings(ode);
ODECalcDrag(ode);
if (ode->mp_derive)
ODECallMPDerivative(ode,t,state,DstateDt);
if (ode->derive)
(*ode->derive)(ode,t,state,DstateDt);
tmpm=ode->next_mass;
while (tmpm!=&ode->next_mass) {
if (!(tmpm->flags&MSF_INACTIVE)) {
if (tmpm->flags&MSF_FIXED) {
D3Zero(&tmpm->DstateDt->DxDt);
D3Zero(&tmpm->DstateDt->x);
} else if (tmpm->mass)
D3DivEqu(&tmpm->DstateDt->DxDt,tmpm->mass);
}
tmpm=tmpm->next;
}
ODEApplyAccelerationLimit(ode);
} else {
if (ode->mp_derive)
ODECallMPDerivative(ode,t,state,DstateDt);
if (ode->derive)
(*ode->derive)(ode,t,state,DstateDt);
}
}
U0 ODEOneStep(CMathODE *ode)
{
I64 i;
ODECallDerivative(ode,ode->t,ode->state_internal,ode->DstateDt);
for (i=0;i<ode->n_internal;i++)
ode->state_internal[i]+=ode->h*ode->DstateDt[i];
ode->t+=ode->h;
}
U0 ODERK4OneStep(CMathODE *ode)
{
I64 i,n=ode->n_internal;
F64 xh,hh,h6,*dym,*dyt,*yt,*DstateDt;
dym =ode->tmp0;
dyt =ode->tmp1;
yt =ode->tmp2;
DstateDt=ode->tmp3;
hh =0.5*ode->h;
h6 =ode->h / 6.0;
xh =ode->t + hh;
ODECallDerivative(ode,ode->t,ode->state_internal,ode->DstateDt);
for (i=0;i<n;i++)
yt[i]=ode->state_internal[i]+hh*DstateDt[i];
ODECallDerivative(ode,xh,yt,dyt);
for (i=0;i<n;i++)
yt[i]=ode->state_internal[i]+hh*dyt[i];
ODECallDerivative(ode,xh,yt,dym);
for (i=0;i<n;i++) {
yt[i]=ode->state_internal[i]+ode->h*dym[i];
dym[i]+=dyt[i];
}
ode->t+=ode->h;
ODECallDerivative(ode,ode->t,yt,dyt);
for (i=0;i<n;i++)
ode->state_internal[i]+=h6*(DstateDt[i]+dyt[i]+2.0*dym[i]);
}
#define ODEa2 0.2
#define ODEa3 0.3
#define ODEa4 0.6
#define ODEa5 1.0
#define ODEa6 0.875
#define ODEb21 0.2
#define ODEb31 (3.0/40.0)
#define ODEb32 (9.0/40.0)
#define ODEb41 0.3
#define ODEb42 (-0.9)
#define ODEb43 1.2
#define ODEb51 (-11.0/54.0)
#define ODEb52 2.5
#define ODEb53 (-70.0/27.0)
#define ODEb54 (35.0/27.0)
#define ODEb61 (1631.0/55296.0)
#define ODEb62 (175.0/512.0)
#define ODEb63 (575.0/13824.0)
#define ODEb64 (44275.0/110592.0)
#define ODEb65 (253.0/4096.0)
#define ODEc1 (37.0/378.0)
#define ODEc3 (250.0/621.0)
#define ODEc4 (125.0/594.0)
#define ODEc6 (512.0/1771.0)
#define ODEdc1 (37.0/378.0-2825.0/27648.0)
#define ODEdc3 (250.0/621.0-18575.0/48384.0)
#define ODEdc4 (125.0/594.0-13525.0/55296.0)
#define ODEdc5 (-277.0/14336.0)
#define ODEdc6 (512.0/1771.0-0.25)
U0 ODECashKarp(CMathODE *ode)
{
I64 i,n=ode->n_internal;
F64 h=ode->h,*state=ode->state_internal,
*DstateDt=ode->DstateDt,*ak2,*ak3,*ak4,*ak5,*ak6,
*tmpstate,*stateerr,*outstate;
ak2=ode->tmp0;
ak3=ode->tmp1;
ak4=ode->tmp2;
ak5=ode->tmp3;
ak6=ode->tmp4;
tmpstate=ode->tmp5;
outstate=ode->tmp6;
stateerr=ode->tmp7;
for (i=0;i<n;i++)
tmpstate[i]=state[i]+ODEb21*h*DstateDt[i];
ODECallDerivative(ode,ode->t+ODEa2*h,tmpstate,ak2);
for (i=0;i<n;i++)
tmpstate[i]=state[i]+h*(ODEb31*DstateDt[i]+ODEb32*ak2[i]);
ODECallDerivative(ode,ode->t+ODEa3*h,tmpstate,ak3);
for (i=0;i<n;i++)
tmpstate[i]=state[i]+h*(ODEb41*DstateDt[i]+ODEb42*ak2[i]+ODEb43*ak3[i]);
ODECallDerivative(ode,ode->t+ODEa4*h,tmpstate,ak4);
for (i=0;i<n;i++)
tmpstate[i]=state[i]+h*(ODEb51*DstateDt[i]+
ODEb52*ak2[i]+ODEb53*ak3[i]+ODEb54*ak4[i]);
ODECallDerivative(ode,ode->t+ODEa5*h,tmpstate,ak5);
for (i=0;i<n;i++)
tmpstate[i]=state[i]+h*(ODEb61*DstateDt[i]+
ODEb62*ak2[i]+ODEb63*ak3[i]+ODEb64*ak4[i]+ODEb65*ak5[i]);
ODECallDerivative(ode,ode->t+ODEa6*h,tmpstate,ak6);
for (i=0;i<n;i++)
outstate[i]=state[i]+h*(ODEc1*DstateDt[i]+
ODEc3*ak3[i]+ODEc4*ak4[i]+ODEc6*ak6[i]);
for (i=0;i<n;i++)
stateerr[i]=h*(ODEdc1*DstateDt[i]+ODEdc3*ak3[i]+
ODEdc4*ak4[i]+ODEdc5*ak5[i]+ODEdc6*ak6[i]);
}
#define SAFETY 0.9
#define PGROW (-0.2)
#define PSHRNK (-0.25)
#define ERRCON 1.89e-4
U0 ODERK5OneStep(CMathODE *ode)
{
I64 i;
F64 errmax,tmp,*tmpstate=ode->tmp6,*stateerr=ode->tmp7;
while (TRUE) {
ode->h=Clamp(ode->h,ode->h_min,ode->h_max);
ODECashKarp(ode);
errmax=0.0;
for (i=0;i<ode->n_internal;i++) {
tmp=Abs(stateerr[i]/ode->state_scale[i]);
if (tmp>errmax)
errmax=tmp;
}
errmax/=ode->tolerance_internal;
if (errmax<=1.0 || ode->h==ode->h_min) break;
tmp=ode->h*SAFETY*errmax`PSHRNK;
if (tmp<0.1*ode->h)
ode->h*=0.1;
else
ode->h=tmp;
}
ode->t+=ode->h;
if (errmax>ERRCON)
ode->h*=SAFETY*errmax`PGROW;
else
ode->h*=5.0;
ode->h=Clamp(ode->h,ode->h_min,ode->h_max);
MemCpy(ode->state_internal,tmpstate,sizeof(F64)*ode->n_internal);
}
F64 ode_alloced_factor=0.75;
U0 ODEsUpdate(CTask *task)
{/* This routine is called by the $LK,"window mgr",A="FF:::/Adam/Gr/GrScrn.HC,ODEsUpdate"$on a continuous
basis to allow real-time simulation. It is intended
to provide ress good enough for games. It uses a runge-kutta
integrator which is a better algorithm than doing it with Euler.
It is adaptive step-sized, so it slows down when an important
event is taking place to improve accuracy, but in my implementation
it has a timeout.
*/
I64 i;
F64 d,start_time,timeout_time,t_desired,t_initial,interpolation;
CMathODE *ode;
if (task->next_ode==&task->next_ode)
task->last_ode_time=0;
else if (!Bt(&task->win_inhibit,WIf_SELF_ODE)) {
//See $LK,"GrUpdateTasks",A="MN:GrUpdateTasks"$() and $LK,"GrUpdateTaskODEs",A="MN:GrUpdateTaskODEs"$().
//We will not pick a time limit based on
//how busy the CPU is, what percent of the
//last refresh cycle was spent on ODE's
//and what the refresh cycle rate was.
start_time=tS;
d=1.0/winmgr.fps;
timeout_time=start_time+
(task->last_ode_time/d+0.1)/(winmgr.last_ode_time/d+0.1)*
ode_alloced_factor*d;
ode=task->next_ode;
while (ode!=&task->next_ode) {
t_initial=ode->t;
d=tS;
if (!(ode->flags&ODEF_STARTED)) {
ode->base_t=d;
ode->flags|=ODEF_STARTED;
}
d-=ode->base_t+t_initial;
t_desired=ode->t_scale*d+t_initial;
if (ode->flags&ODEF_PAUSED)
ode->base_t+=t_desired-ode->t; //Slip
else {
ode->flags|=ODEF_BUSY;
if (ode->flags&ODEF_PAUSED)
ode->base_t+=t_desired-ode->t; //Slip
else {
if (ode->derive || ode->mp_derive) {
if (ode->mp_derive)
ODEMPWake(ode);
ODEState2Internal(ode);
MemCpy(ode->initial_state,ode->state_internal,
ode->n_internal*sizeof(F64));
while (ode->t<t_desired) {
ode->h_max=t_desired-ode->t;
ODECallDerivative(ode,ode->t,ode->state_internal,ode->DstateDt);
for (i=0;i<ode->n_internal;i++)
ode->state_scale[i]=Abs(ode->state_internal[i])+
Abs(ode->DstateDt[i]*ode->h)+ode->tolerance_internal;
ODERK5OneStep(ode);
if (tS>timeout_time) {
ode->base_t+=t_desired-ode->t; //Slip
goto ode_done;
}
}
//Interpolate if end time was not exact.
if (ode->t!=t_desired) {
if (interpolation=ode->t-t_initial) {
interpolation=(t_desired-t_initial)/interpolation;
if (interpolation!=1.0)
for (i=0;i<ode->n_internal;i++)
ode->state_internal[i]=(ode->state_internal[i]-
ode->initial_state[i])*interpolation+
ode->initial_state[i];
}
ode->t=t_desired;
}
ode_done:
ODEInternal2State(ode);
//Convenience call to set vals
ODECallDerivative(ode,ode->t,ode->state_internal,ode->DstateDt);
if (ode->mp_derive)
ODEMPSleep(ode);
}
}
ode->flags&=~ODEF_BUSY;
}
ode->base_t+=(1.0-ode->t_scale)*d;
ode=ode->next;
}
//Now, we will dynamically adjust tolerances.
//We will regulate the tolerances
//to fill the time we decided was
//okay to devote to ODE's.
//Since we might have multiple ODE's
//active we scale them by the same factor.
//This algorithm is probably not stable or very good, but it's something.
//Target is 75% of alloced time.
d=(tS-start_time)/(timeout_time-start_time)-0.75;
ode=task->next_ode;
while (ode!=&task->next_ode) {
if (!(ode->flags&ODEF_PAUSED) && ode->derive) {
if (ode->min_tolerance!=ode->max_tolerance) {
if (d>0)
ode->tolerance_internal*=10.0`d;
else
ode->tolerance_internal*=2.0`d;
}
ode->tolerance_internal=Clamp(ode->tolerance_internal,
ode->min_tolerance,ode->max_tolerance);
}
ode=ode->next;
}
winmgr.ode_time+=task->last_ode_time=tS-start_time;
}
}