1 /* $Id: vecmat.c,v 1.5 2003/02/18 20:23:22 btb Exp $ */
2 /*
3 THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
4 SOFTWARE CORPORATION ("PARALLAX"). PARALLAX, IN DISTRIBUTING THE CODE TO
5 END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
6 ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
7 IN USING, DISPLAYING, AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
8 SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
9 FREE PURPOSES. IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
10 CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES. THE END-USER UNDERSTANDS
11 AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
12 COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION. ALL RIGHTS RESERVED.
13 */
14
15 /*
16 *
17 * C version of vecmat library
18 *
19 * Old Log:
20 * Revision 1.5 1995/10/30 11:08:16 allender
21 * fix check_vec to return if vector is the NULL vector
22 *
23 * Revision 1.4 1995/09/23 09:38:14 allender
24 * removed calls for PPC that are now handled in asm
25 *
26 * Revision 1.3 1995/08/31 15:50:24 allender
27 * fixing up of functions for PPC
28 *
29 * Revision 1.2 1995/07/05 16:40:21 allender
30 * some vecmat stuff might be using isqrt -- commented out
31 * for now
32 *
33 * Revision 1.1 1995/04/17 16:18:02 allender
34 * Initial revision
35 *
36 *
37 * --- PC RCS Information ---
38 * Revision 1.1 1995/03/08 15:56:50 matt
39 * Initial revision
40 *
41 *
42 */
43
44 #ifdef HAVE_CONFIG_H
45 #include <conf.h>
46 #endif
47
48 #ifdef RCS
49 static char rcsid[] = "$Id: vecmat.c,v 1.5 2003/02/18 20:23:22 btb Exp $";
50 #endif
51
52 #include <stdlib.h>
53 #include <math.h> // for sqrt
54
55 #include "maths.h"
56 #include "vecmat.h"
57 #include "error.h"
58
59 //#define USE_ISQRT 1
60
61 #ifndef ASM_VECMAT
62 vms_vector vmd_zero_vector = {0,0,0};
63 vms_matrix vmd_identity_matrix = { { f1_0,0,0 },
64 { 0,f1_0,0 },
65 {0,0,f1_0} };
66
67 //adds two vectors, fills in dest, returns ptr to dest
68 //ok for dest to equal either source, but should use vm_vec_add2() if so
vm_vec_add(vms_vector * dest,vms_vector * src0,vms_vector * src1)69 vms_vector *vm_vec_add(vms_vector *dest,vms_vector *src0,vms_vector *src1)
70 {
71 dest->x = src0->x + src1->x;
72 dest->y = src0->y + src1->y;
73 dest->z = src0->z + src1->z;
74
75 return dest;
76 }
77
78
79 //subs two vectors, fills in dest, returns ptr to dest
80 //ok for dest to equal either source, but should use vm_vec_sub2() if so
vm_vec_sub(vms_vector * dest,vms_vector * src0,vms_vector * src1)81 vms_vector *vm_vec_sub(vms_vector *dest,vms_vector *src0,vms_vector *src1)
82 {
83 dest->x = src0->x - src1->x;
84 dest->y = src0->y - src1->y;
85 dest->z = src0->z - src1->z;
86
87 return dest;
88 }
89
90 //adds one vector to another. returns ptr to dest
91 //dest can equal source
vm_vec_add2(vms_vector * dest,vms_vector * src)92 vms_vector *vm_vec_add2(vms_vector *dest,vms_vector *src)
93 {
94 dest->x += src->x;
95 dest->y += src->y;
96 dest->z += src->z;
97
98 return dest;
99 }
100
101 //subs one vector from another, returns ptr to dest
102 //dest can equal source
vm_vec_sub2(vms_vector * dest,vms_vector * src)103 vms_vector *vm_vec_sub2(vms_vector *dest,vms_vector *src)
104 {
105 dest->x -= src->x;
106 dest->y -= src->y;
107 dest->z -= src->z;
108
109 return dest;
110 }
111
112 //averages two vectors. returns ptr to dest
113 //dest can equal either source
vm_vec_avg(vms_vector * dest,vms_vector * src0,vms_vector * src1)114 vms_vector *vm_vec_avg(vms_vector *dest,vms_vector *src0,vms_vector *src1)
115 {
116 dest->x = (src0->x + src1->x)/2;
117 dest->y = (src0->y + src1->y)/2;
118 dest->z = (src0->z + src1->z)/2;
119
120 return dest;
121 }
122
123
124 //averages four vectors. returns ptr to dest
125 //dest can equal any source
vm_vec_avg4(vms_vector * dest,vms_vector * src0,vms_vector * src1,vms_vector * src2,vms_vector * src3)126 vms_vector *vm_vec_avg4(vms_vector *dest,vms_vector *src0,vms_vector *src1,vms_vector *src2,vms_vector *src3)
127 {
128 dest->x = (src0->x + src1->x + src2->x + src3->x)/4;
129 dest->y = (src0->y + src1->y + src2->y + src3->y)/4;
130 dest->z = (src0->z + src1->z + src2->z + src3->z)/4;
131
132 return dest;
133 }
134
135
136 //scales a vector in place. returns ptr to vector
vm_vec_scale(vms_vector * dest,fix s)137 vms_vector *vm_vec_scale(vms_vector *dest,fix s)
138 {
139 dest->x = fixmul(dest->x,s);
140 dest->y = fixmul(dest->y,s);
141 dest->z = fixmul(dest->z,s);
142
143 return dest;
144 }
145
146 //scales and copies a vector. returns ptr to dest
vm_vec_copy_scale(vms_vector * dest,vms_vector * src,fix s)147 vms_vector *vm_vec_copy_scale(vms_vector *dest,vms_vector *src,fix s)
148 {
149 dest->x = fixmul(src->x,s);
150 dest->y = fixmul(src->y,s);
151 dest->z = fixmul(src->z,s);
152
153 return dest;
154 }
155
156 //scales a vector, adds it to another, and stores in a 3rd vector
157 //dest = src1 + k * src2
vm_vec_scale_add(vms_vector * dest,vms_vector * src1,vms_vector * src2,fix k)158 vms_vector *vm_vec_scale_add(vms_vector *dest,vms_vector *src1,vms_vector *src2,fix k)
159 {
160 dest->x = src1->x + fixmul(src2->x,k);
161 dest->y = src1->y + fixmul(src2->y,k);
162 dest->z = src1->z + fixmul(src2->z,k);
163
164 return dest;
165 }
166
167 //scales a vector and adds it to another
168 //dest += k * src
vm_vec_scale_add2(vms_vector * dest,vms_vector * src,fix k)169 vms_vector *vm_vec_scale_add2(vms_vector *dest,vms_vector *src,fix k)
170 {
171 dest->x += fixmul(src->x,k);
172 dest->y += fixmul(src->y,k);
173 dest->z += fixmul(src->z,k);
174
175 return dest;
176 }
177
178 //scales a vector in place, taking n/d for scale. returns ptr to vector
179 //dest *= n/d
vm_vec_scale2(vms_vector * dest,fix n,fix d)180 vms_vector *vm_vec_scale2(vms_vector *dest,fix n,fix d)
181 {
182 #if 1 // DPH: Kludge: this was overflowing a lot, so I made it use the FPU.
183 float nd;
184 // printf("scale n=%d d=%d\n",n,d);
185 nd = f2fl(n) / f2fl(d);
186 dest->x = fl2f( f2fl(dest->x) * nd);
187 dest->y = fl2f( f2fl(dest->y) * nd);
188 dest->z = fl2f( f2fl(dest->z) * nd);
189 #else
190 dest->x = fixmuldiv(dest->x,n,d);
191 dest->y = fixmuldiv(dest->y,n,d);
192 dest->z = fixmuldiv(dest->z,n,d);
193 #endif
194
195 return dest;
196 }
197
vm_vec_dotprod(vms_vector * v0,vms_vector * v1)198 fix vm_vec_dotprod(vms_vector *v0,vms_vector *v1)
199 {
200 quadint q;
201
202 q.low = q.high = 0;
203
204 fixmulaccum(&q,v0->x,v1->x);
205 fixmulaccum(&q,v0->y,v1->y);
206 fixmulaccum(&q,v0->z,v1->z);
207
208 return fixquadadjust(&q);
209 }
210
vm_vec_dot3(fix x,fix y,fix z,vms_vector * v)211 fix vm_vec_dot3(fix x,fix y,fix z,vms_vector *v)
212 {
213 quadint q;
214
215 q.low = q.high = 0;
216
217 fixmulaccum(&q,x,v->x);
218 fixmulaccum(&q,y,v->y);
219 fixmulaccum(&q,z,v->z);
220
221 return fixquadadjust(&q);
222 }
223
224 //returns magnitude of a vector
vm_vec_mag(vms_vector * v)225 fix vm_vec_mag(vms_vector *v)
226 {
227 quadint q;
228
229 q.low = q.high = 0;
230
231 fixmulaccum(&q,v->x,v->x);
232 fixmulaccum(&q,v->y,v->y);
233 fixmulaccum(&q,v->z,v->z);
234
235 return quad_sqrt(q.low,q.high);
236 }
237
238 //computes the distance between two points. (does sub and mag)
vm_vec_dist(vms_vector * v0,vms_vector * v1)239 fix vm_vec_dist(vms_vector *v0,vms_vector *v1)
240 {
241 vms_vector t;
242
243 vm_vec_sub(&t,v0,v1);
244
245 return vm_vec_mag(&t);
246 }
247
248
249 //computes an approximation of the magnitude of the vector
250 //uses dist = largest + next_largest*3/8 + smallest*3/16
vm_vec_mag_quick(vms_vector * v)251 fix vm_vec_mag_quick(vms_vector *v)
252 {
253 fix a,b,c,bc;
254
255 a = labs(v->x);
256 b = labs(v->y);
257 c = labs(v->z);
258
259 if (a < b) {
260 fix t=a; a=b; b=t;
261 }
262
263 if (b < c) {
264 fix t=b; b=c; c=t;
265
266 if (a < b) {
267 fix t=a; a=b; b=t;
268 }
269 }
270
271 bc = (b>>2) + (c>>3);
272
273 return a + bc + (bc>>1);
274 }
275
276
277 //computes an approximation of the distance between two points.
278 //uses dist = largest + next_largest*3/8 + smallest*3/16
vm_vec_dist_quick(vms_vector * v0,vms_vector * v1)279 fix vm_vec_dist_quick(vms_vector *v0,vms_vector *v1)
280 {
281 vms_vector t;
282
283 vm_vec_sub(&t,v0,v1);
284
285 return vm_vec_mag_quick(&t);
286 }
287
288 //normalize a vector. returns mag of source vec
vm_vec_copy_normalize(vms_vector * dest,vms_vector * src)289 fix vm_vec_copy_normalize(vms_vector *dest,vms_vector *src)
290 {
291 fix m;
292
293 m = vm_vec_mag(src);
294
295 if (m > 0) {
296 dest->x = fixdiv(src->x,m);
297 dest->y = fixdiv(src->y,m);
298 dest->z = fixdiv(src->z,m);
299 }
300
301 return m;
302 }
303
304 //normalize a vector. returns mag of source vec
vm_vec_normalize(vms_vector * v)305 fix vm_vec_normalize(vms_vector *v)
306 {
307 return vm_vec_copy_normalize(v,v);
308 }
309
310 #ifndef USE_ISQRT
311 //normalize a vector. returns mag of source vec. uses approx mag
vm_vec_copy_normalize_quick(vms_vector * dest,vms_vector * src)312 fix vm_vec_copy_normalize_quick(vms_vector *dest,vms_vector *src)
313 {
314 fix m;
315
316 m = vm_vec_mag_quick(src);
317
318 if (m > 0) {
319 dest->x = fixdiv(src->x,m);
320 dest->y = fixdiv(src->y,m);
321 dest->z = fixdiv(src->z,m);
322 }
323
324 return m;
325 }
326
327 #else
328 //these routines use an approximation for 1/sqrt
329
330 //returns approximation of 1/magnitude of a vector
vm_vec_imag(vms_vector * v)331 fix vm_vec_imag(vms_vector *v)
332 {
333 quadint q;
334
335 q.low = q.high = 0;
336
337 fixmulaccum(&q,v->x,v->x);
338 fixmulaccum(&q,v->y,v->y);
339 fixmulaccum(&q,v->z,v->z);
340
341 if (q.high==0)
342 return fix_isqrt(fixquadadjust(&q));
343 else if (q.high >= 0x800000) {
344 return (fix_isqrt(q.high) >> 8);
345 }
346 else
347 return (fix_isqrt((q.high<<8) + (q.low>>24)) >> 4);
348 }
349
350 //normalize a vector. returns 1/mag of source vec. uses approx 1/mag
vm_vec_copy_normalize_quick(vms_vector * dest,vms_vector * src)351 fix vm_vec_copy_normalize_quick(vms_vector *dest,vms_vector *src)
352 {
353 fix im;
354
355 im = vm_vec_imag(src);
356
357 dest->x = fixmul(src->x,im);
358 dest->y = fixmul(src->y,im);
359 dest->z = fixmul(src->z,im);
360
361 return im;
362 }
363
364 #endif
365
366 //normalize a vector. returns 1/mag of source vec. uses approx 1/mag
vm_vec_normalize_quick(vms_vector * v)367 fix vm_vec_normalize_quick(vms_vector *v)
368 {
369 return vm_vec_copy_normalize_quick(v,v);
370 }
371
372 //return the normalized direction vector between two points
373 //dest = normalized(end - start). Returns 1/mag of direction vector
374 //NOTE: the order of the parameters matches the vector subtraction
vm_vec_normalized_dir_quick(vms_vector * dest,vms_vector * end,vms_vector * start)375 fix vm_vec_normalized_dir_quick(vms_vector *dest,vms_vector *end,vms_vector *start)
376 {
377 vm_vec_sub(dest,end,start);
378
379 return vm_vec_normalize_quick(dest);
380 }
381
382 //return the normalized direction vector between two points
383 //dest = normalized(end - start). Returns mag of direction vector
384 //NOTE: the order of the parameters matches the vector subtraction
vm_vec_normalized_dir(vms_vector * dest,vms_vector * end,vms_vector * start)385 fix vm_vec_normalized_dir(vms_vector *dest,vms_vector *end,vms_vector *start)
386 {
387 vm_vec_sub(dest,end,start);
388
389 return vm_vec_normalize(dest);
390 }
391
392 //computes surface normal from three points. result is normalized
393 //returns ptr to dest
394 //dest CANNOT equal either source
vm_vec_normal(vms_vector * dest,vms_vector * p0,vms_vector * p1,vms_vector * p2)395 vms_vector *vm_vec_normal(vms_vector *dest,vms_vector *p0,vms_vector *p1,vms_vector *p2)
396 {
397 vm_vec_perp(dest,p0,p1,p2);
398
399 vm_vec_normalize(dest);
400
401 return dest;
402 }
403
404 //make sure a vector is reasonably sized to go into a cross product
check_vec(vms_vector * v)405 void check_vec(vms_vector *v)
406 {
407 fix check;
408 int cnt = 0;
409
410 check = labs(v->x) | labs(v->y) | labs(v->z);
411
412 if (check == 0)
413 return;
414
415 if (check & 0xfffc0000) { //too big
416
417 while (check & 0xfff00000) {
418 cnt += 4;
419 check >>= 4;
420 }
421
422 while (check & 0xfffc0000) {
423 cnt += 2;
424 check >>= 2;
425 }
426
427 v->x >>= cnt;
428 v->y >>= cnt;
429 v->z >>= cnt;
430 }
431 else //maybe too small
432 if ((check & 0xffff8000) == 0) { //yep, too small
433
434 while ((check & 0xfffff000) == 0) {
435 cnt += 4;
436 check <<= 4;
437 }
438
439 while ((check & 0xffff8000) == 0) {
440 cnt += 2;
441 check <<= 2;
442 }
443
444 v->x >>= cnt;
445 v->y >>= cnt;
446 v->z >>= cnt;
447 }
448 }
449
450 //computes cross product of two vectors.
451 //Note: this magnitude of the resultant vector is the
452 //product of the magnitudes of the two source vectors. This means it is
453 //quite easy for this routine to overflow and underflow. Be careful that
454 //your inputs are ok.
455 //#ifndef __powerc
456 #if 0
457 vms_vector *vm_vec_crossprod(vms_vector *dest,vms_vector *src0,vms_vector *src1)
458 {
459 double d;
460 Assert(dest!=src0 && dest!=src1);
461
462 d = (double)(src0->y) * (double)(src1->z);
463 d += (double)-(src0->z) * (double)(src1->y);
464 d /= 65536.0;
465 if (d < 0.0)
466 d = d - 1.0;
467 dest->x = (fix)d;
468
469 d = (double)(src0->z) * (double)(src1->x);
470 d += (double)-(src0->x) * (double)(src1->z);
471 d /= 65536.0;
472 if (d < 0.0)
473 d = d - 1.0;
474 dest->y = (fix)d;
475
476 d = (double)(src0->x) * (double)(src1->y);
477 d += (double)-(src0->y) * (double)(src1->x);
478 d /= 65536.0;
479 if (d < 0.0)
480 d = d - 1.0;
481 dest->z = (fix)d;
482
483 return dest;
484 }
485 #else
486
vm_vec_crossprod(vms_vector * dest,vms_vector * src0,vms_vector * src1)487 vms_vector *vm_vec_crossprod(vms_vector *dest,vms_vector *src0,vms_vector *src1)
488 {
489 quadint q;
490
491 Assert(dest!=src0 && dest!=src1);
492
493 q.low = q.high = 0;
494 fixmulaccum(&q,src0->y,src1->z);
495 fixmulaccum(&q,-src0->z,src1->y);
496 dest->x = fixquadadjust(&q);
497
498 q.low = q.high = 0;
499 fixmulaccum(&q,src0->z,src1->x);
500 fixmulaccum(&q,-src0->x,src1->z);
501 dest->y = fixquadadjust(&q);
502
503 q.low = q.high = 0;
504 fixmulaccum(&q,src0->x,src1->y);
505 fixmulaccum(&q,-src0->y,src1->x);
506 dest->z = fixquadadjust(&q);
507
508 return dest;
509 }
510
511 #endif
512
513
514 //computes non-normalized surface normal from three points.
515 //returns ptr to dest
516 //dest CANNOT equal either source
vm_vec_perp(vms_vector * dest,vms_vector * p0,vms_vector * p1,vms_vector * p2)517 vms_vector *vm_vec_perp(vms_vector *dest,vms_vector *p0,vms_vector *p1,vms_vector *p2)
518 {
519 vms_vector t0,t1;
520
521 vm_vec_sub(&t0,p1,p0);
522 vm_vec_sub(&t1,p2,p1);
523
524 check_vec(&t0);
525 check_vec(&t1);
526
527 return vm_vec_crossprod(dest,&t0,&t1);
528 }
529
530
531 //computes the delta angle between two vectors.
532 //vectors need not be normalized. if they are, call vm_vec_delta_ang_norm()
533 //the forward vector (third parameter) can be NULL, in which case the absolute
534 //value of the angle in returned. Otherwise the angle around that vector is
535 //returned.
vm_vec_delta_ang(vms_vector * v0,vms_vector * v1,vms_vector * fvec)536 fixang vm_vec_delta_ang(vms_vector *v0,vms_vector *v1,vms_vector *fvec)
537 {
538 vms_vector t0,t1;
539
540 vm_vec_copy_normalize(&t0,v0);
541 vm_vec_copy_normalize(&t1,v1);
542
543 return vm_vec_delta_ang_norm(&t0,&t1,fvec);
544 }
545
546 //computes the delta angle between two normalized vectors.
vm_vec_delta_ang_norm(vms_vector * v0,vms_vector * v1,vms_vector * fvec)547 fixang vm_vec_delta_ang_norm(vms_vector *v0,vms_vector *v1,vms_vector *fvec)
548 {
549 fixang a;
550
551 a = fix_acos(vm_vec_dot(v0,v1));
552
553 if (fvec) {
554 vms_vector t;
555
556 vm_vec_cross(&t,v0,v1);
557
558 if (vm_vec_dot(&t,fvec) < 0)
559 a = -a;
560 }
561
562 return a;
563 }
564
sincos_2_matrix(vms_matrix * m,fix sinp,fix cosp,fix sinb,fix cosb,fix sinh,fix cosh)565 vms_matrix *sincos_2_matrix(vms_matrix *m,fix sinp,fix cosp,fix sinb,fix cosb,fix sinh,fix cosh)
566 {
567 fix sbsh,cbch,cbsh,sbch;
568
569 sbsh = fixmul(sinb,sinh);
570 cbch = fixmul(cosb,cosh);
571 cbsh = fixmul(cosb,sinh);
572 sbch = fixmul(sinb,cosh);
573
574 m->rvec.x = cbch + fixmul(sinp,sbsh); //m1
575 m->uvec.z = sbsh + fixmul(sinp,cbch); //m8
576
577 m->uvec.x = fixmul(sinp,cbsh) - sbch; //m2
578 m->rvec.z = fixmul(sinp,sbch) - cbsh; //m7
579
580 m->fvec.x = fixmul(sinh,cosp); //m3
581 m->rvec.y = fixmul(sinb,cosp); //m4
582 m->uvec.y = fixmul(cosb,cosp); //m5
583 m->fvec.z = fixmul(cosh,cosp); //m9
584
585 m->fvec.y = -sinp; //m6
586
587 return m;
588
589 }
590
591 //computes a matrix from a set of three angles. returns ptr to matrix
vm_angles_2_matrix(vms_matrix * m,vms_angvec * a)592 vms_matrix *vm_angles_2_matrix(vms_matrix *m,vms_angvec *a)
593 {
594 fix sinp,cosp,sinb,cosb,sinh,cosh;
595
596 fix_sincos(a->p,&sinp,&cosp);
597 fix_sincos(a->b,&sinb,&cosb);
598 fix_sincos(a->h,&sinh,&cosh);
599
600 return sincos_2_matrix(m,sinp,cosp,sinb,cosb,sinh,cosh);
601
602 }
603
604 //computes a matrix from a forward vector and an angle
vm_vec_ang_2_matrix(vms_matrix * m,vms_vector * v,fixang a)605 vms_matrix *vm_vec_ang_2_matrix(vms_matrix *m,vms_vector *v,fixang a)
606 {
607 fix sinb,cosb,sinp,cosp,sinh,cosh;
608
609 fix_sincos(a,&sinb,&cosb);
610
611 sinp = -v->y;
612 cosp = fix_sqrt(f1_0 - fixmul(sinp,sinp));
613
614 sinh = fixdiv(v->x,cosp);
615 cosh = fixdiv(v->z,cosp);
616
617 return sincos_2_matrix(m,sinp,cosp,sinb,cosb,sinh,cosh);
618 }
619
620
621 //computes a matrix from one or more vectors. The forward vector is required,
622 //with the other two being optional. If both up & right vectors are passed,
623 //the up vector is used. If only the forward vector is passed, a bank of
624 //zero is assumed
625 //returns ptr to matrix
vm_vector_2_matrix(vms_matrix * m,vms_vector * fvec,vms_vector * uvec,vms_vector * rvec)626 vms_matrix *vm_vector_2_matrix(vms_matrix *m,vms_vector *fvec,vms_vector *uvec,vms_vector *rvec)
627 {
628 vms_vector *xvec=&m->rvec,*yvec=&m->uvec,*zvec=&m->fvec;
629
630 Assert(fvec != NULL);
631
632 if (vm_vec_copy_normalize(zvec,fvec) == 0) {
633 Int3(); //forward vec should not be zero-length
634 return m;
635 }
636
637 if (uvec == NULL) {
638
639 if (rvec == NULL) { //just forward vec
640
641 bad_vector2:
642 ;
643
644 if (zvec->x==0 && zvec->z==0) { //forward vec is straight up or down
645
646 m->rvec.x = f1_0;
647 m->uvec.z = (zvec->y<0)?f1_0:-f1_0;
648
649 m->rvec.y = m->rvec.z = m->uvec.x = m->uvec.y = 0;
650 }
651 else { //not straight up or down
652
653 xvec->x = zvec->z;
654 xvec->y = 0;
655 xvec->z = -zvec->x;
656
657 vm_vec_normalize(xvec);
658
659 vm_vec_crossprod(yvec,zvec,xvec);
660
661 }
662
663 }
664 else { //use right vec
665
666 if (vm_vec_copy_normalize(xvec,rvec) == 0)
667 goto bad_vector2;
668
669 vm_vec_crossprod(yvec,zvec,xvec);
670
671 //normalize new perpendicular vector
672 if (vm_vec_normalize(yvec) == 0)
673 goto bad_vector2;
674
675 //now recompute right vector, in case it wasn't entirely perpendiclar
676 vm_vec_crossprod(xvec,yvec,zvec);
677
678 }
679 }
680 else { //use up vec
681
682 if (vm_vec_copy_normalize(yvec,uvec) == 0)
683 goto bad_vector2;
684
685 vm_vec_crossprod(xvec,yvec,zvec);
686
687 //normalize new perpendicular vector
688 if (vm_vec_normalize(xvec) == 0)
689 goto bad_vector2;
690
691 //now recompute up vector, in case it wasn't entirely perpendiclar
692 vm_vec_crossprod(yvec,zvec,xvec);
693
694 }
695
696 return m;
697 }
698
699
700 //quicker version of vm_vector_2_matrix() that takes normalized vectors
vm_vector_2_matrix_norm(vms_matrix * m,vms_vector * fvec,vms_vector * uvec,vms_vector * rvec)701 vms_matrix *vm_vector_2_matrix_norm(vms_matrix *m,vms_vector *fvec,vms_vector *uvec,vms_vector *rvec)
702 {
703 vms_vector *xvec=&m->rvec,*yvec=&m->uvec,*zvec=&m->fvec;
704
705 Assert(fvec != NULL);
706
707 if (uvec == NULL) {
708
709 if (rvec == NULL) { //just forward vec
710
711 bad_vector2:
712 ;
713
714 if (zvec->x==0 && zvec->z==0) { //forward vec is straight up or down
715
716 m->rvec.x = f1_0;
717 m->uvec.z = (zvec->y<0)?f1_0:-f1_0;
718
719 m->rvec.y = m->rvec.z = m->uvec.x = m->uvec.y = 0;
720 }
721 else { //not straight up or down
722
723 xvec->x = zvec->z;
724 xvec->y = 0;
725 xvec->z = -zvec->x;
726
727 vm_vec_normalize(xvec);
728
729 vm_vec_crossprod(yvec,zvec,xvec);
730
731 }
732
733 }
734 else { //use right vec
735
736 vm_vec_crossprod(yvec,zvec,xvec);
737
738 //normalize new perpendicular vector
739 if (vm_vec_normalize(yvec) == 0)
740 goto bad_vector2;
741
742 //now recompute right vector, in case it wasn't entirely perpendiclar
743 vm_vec_crossprod(xvec,yvec,zvec);
744
745 }
746 }
747 else { //use up vec
748
749 vm_vec_crossprod(xvec,yvec,zvec);
750
751 //normalize new perpendicular vector
752 if (vm_vec_normalize(xvec) == 0)
753 goto bad_vector2;
754
755 //now recompute up vector, in case it wasn't entirely perpendiclar
756 vm_vec_crossprod(yvec,zvec,xvec);
757
758 }
759
760 return m;
761 }
762
763
764 //rotates a vector through a matrix. returns ptr to dest vector
765 //dest CANNOT equal source
vm_vec_rotate(vms_vector * dest,vms_vector * src,vms_matrix * m)766 vms_vector *vm_vec_rotate(vms_vector *dest,vms_vector *src,vms_matrix *m)
767 {
768 Assert(dest != src);
769
770 dest->x = vm_vec_dot(src,&m->rvec);
771 dest->y = vm_vec_dot(src,&m->uvec);
772 dest->z = vm_vec_dot(src,&m->fvec);
773
774 return dest;
775 }
776
777
778 //transpose a matrix in place. returns ptr to matrix
vm_transpose_matrix(vms_matrix * m)779 vms_matrix *vm_transpose_matrix(vms_matrix *m)
780 {
781 fix t;
782
783 t = m->uvec.x; m->uvec.x = m->rvec.y; m->rvec.y = t;
784 t = m->fvec.x; m->fvec.x = m->rvec.z; m->rvec.z = t;
785 t = m->fvec.y; m->fvec.y = m->uvec.z; m->uvec.z = t;
786
787 return m;
788 }
789
790 //copy and transpose a matrix. returns ptr to matrix
791 //dest CANNOT equal source. use vm_transpose_matrix() if this is the case
vm_copy_transpose_matrix(vms_matrix * dest,vms_matrix * src)792 vms_matrix *vm_copy_transpose_matrix(vms_matrix *dest,vms_matrix *src)
793 {
794 Assert(dest != src);
795
796 dest->rvec.x = src->rvec.x;
797 dest->rvec.y = src->uvec.x;
798 dest->rvec.z = src->fvec.x;
799
800 dest->uvec.x = src->rvec.y;
801 dest->uvec.y = src->uvec.y;
802 dest->uvec.z = src->fvec.y;
803
804 dest->fvec.x = src->rvec.z;
805 dest->fvec.y = src->uvec.z;
806 dest->fvec.z = src->fvec.z;
807
808 return dest;
809 }
810
811 //mulitply 2 matrices, fill in dest. returns ptr to dest
812 //dest CANNOT equal either source
vm_matrix_x_matrix(vms_matrix * dest,vms_matrix * src0,vms_matrix * src1)813 vms_matrix *vm_matrix_x_matrix(vms_matrix *dest,vms_matrix *src0,vms_matrix *src1)
814 {
815 Assert(dest!=src0 && dest!=src1);
816
817 dest->rvec.x = vm_vec_dot3(src0->rvec.x,src0->uvec.x,src0->fvec.x, &src1->rvec);
818 dest->uvec.x = vm_vec_dot3(src0->rvec.x,src0->uvec.x,src0->fvec.x, &src1->uvec);
819 dest->fvec.x = vm_vec_dot3(src0->rvec.x,src0->uvec.x,src0->fvec.x, &src1->fvec);
820
821 dest->rvec.y = vm_vec_dot3(src0->rvec.y,src0->uvec.y,src0->fvec.y, &src1->rvec);
822 dest->uvec.y = vm_vec_dot3(src0->rvec.y,src0->uvec.y,src0->fvec.y, &src1->uvec);
823 dest->fvec.y = vm_vec_dot3(src0->rvec.y,src0->uvec.y,src0->fvec.y, &src1->fvec);
824
825 dest->rvec.z = vm_vec_dot3(src0->rvec.z,src0->uvec.z,src0->fvec.z, &src1->rvec);
826 dest->uvec.z = vm_vec_dot3(src0->rvec.z,src0->uvec.z,src0->fvec.z, &src1->uvec);
827 dest->fvec.z = vm_vec_dot3(src0->rvec.z,src0->uvec.z,src0->fvec.z, &src1->fvec);
828
829 return dest;
830 }
831 #endif
832
833
834 //extract angles from a matrix
vm_extract_angles_matrix(vms_angvec * a,vms_matrix * m)835 vms_angvec *vm_extract_angles_matrix(vms_angvec *a,vms_matrix *m)
836 {
837 fix sinh,cosh,cosp;
838
839 if (m->fvec.x==0 && m->fvec.z==0) //zero head
840 a->h = 0;
841 else
842 a->h = fix_atan2(m->fvec.z,m->fvec.x);
843
844 fix_sincos(a->h,&sinh,&cosh);
845
846 if (abs(sinh) > abs(cosh)) //sine is larger, so use it
847 cosp = fixdiv(m->fvec.x,sinh);
848 else //cosine is larger, so use it
849 cosp = fixdiv(m->fvec.z,cosh);
850
851 if (cosp==0 && m->fvec.y==0)
852 a->p = 0;
853 else
854 a->p = fix_atan2(cosp,-m->fvec.y);
855
856
857 if (cosp == 0) //the cosine of pitch is zero. we're pitched straight up. say no bank
858
859 a->b = 0;
860
861 else {
862 fix sinb,cosb;
863
864 sinb = fixdiv(m->rvec.y,cosp);
865 cosb = fixdiv(m->uvec.y,cosp);
866
867 if (sinb==0 && cosb==0)
868 a->b = 0;
869 else
870 a->b = fix_atan2(cosb,sinb);
871
872 }
873
874 return a;
875 }
876
877
878 //extract heading and pitch from a vector, assuming bank==0
vm_extract_angles_vector_normalized(vms_angvec * a,vms_vector * v)879 vms_angvec *vm_extract_angles_vector_normalized(vms_angvec *a,vms_vector *v)
880 {
881 a->b = 0; //always zero bank
882
883 a->p = fix_asin(-v->y);
884
885 if (v->x==0 && v->z==0)
886 a->h = 0;
887 else
888 a->h = fix_atan2(v->z,v->x);
889
890 return a;
891 }
892
893 //extract heading and pitch from a vector, assuming bank==0
vm_extract_angles_vector(vms_angvec * a,vms_vector * v)894 vms_angvec *vm_extract_angles_vector(vms_angvec *a,vms_vector *v)
895 {
896 vms_vector t;
897
898 if (vm_vec_copy_normalize(&t,v) != 0)
899 vm_extract_angles_vector_normalized(a,&t);
900
901 return a;
902
903 }
904
905 //compute the distance from a point to a plane. takes the normalized normal
906 //of the plane (ebx), a point on the plane (edi), and the point to check (esi).
907 //returns distance in eax
908 //distance is signed, so negative dist is on the back of the plane
vm_dist_to_plane(vms_vector * checkp,vms_vector * norm,vms_vector * planep)909 fix vm_dist_to_plane(vms_vector *checkp,vms_vector *norm,vms_vector *planep)
910 {
911 vms_vector t;
912
913 vm_vec_sub(&t,checkp,planep);
914
915 return vm_vec_dot(&t,norm);
916
917 }
918
vm_vec_make(vms_vector * v,fix x,fix y,fix z)919 vms_vector *vm_vec_make(vms_vector *v,fix x,fix y,fix z) {
920 v->x=x; v->y=y; v->z=z;
921 return v;
922 }
923
924
925