2 THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
3 SOFTWARE CORPORATION ("PARALLAX"). PARALLAX, IN DISTRIBUTING THE CODE TO
4 END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
5 ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
6 IN USING, DISPLAYING, AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
7 SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
8 FREE PURPOSES. IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
9 CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES. THE END-USER UNDERSTANDS
10 AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
11 COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION. ALL RIGHTS RESERVED.
16 * C version of vecmat library
25 #include <math.h> // for sqrt
34 vms_vector vmd_zero_vector = {0, 0, 0};
35 vms_matrix vmd_identity_matrix = { { f1_0, 0, 0 },
39 //adds two vectors, fills in dest, returns ptr to dest
40 //ok for dest to equal either source, but should use vm_vec_add2() if so
41 vms_vector *vm_vec_add(vms_vector *dest,vms_vector *src0,vms_vector *src1)
43 dest->x = src0->x + src1->x;
44 dest->y = src0->y + src1->y;
45 dest->z = src0->z + src1->z;
51 //subs two vectors, fills in dest, returns ptr to dest
52 //ok for dest to equal either source, but should use vm_vec_sub2() if so
53 vms_vector *vm_vec_sub(vms_vector *dest,vms_vector *src0,vms_vector *src1)
55 dest->x = src0->x - src1->x;
56 dest->y = src0->y - src1->y;
57 dest->z = src0->z - src1->z;
62 //adds one vector to another. returns ptr to dest
63 //dest can equal source
64 vms_vector *vm_vec_add2(vms_vector *dest,vms_vector *src)
73 //subs one vector from another, returns ptr to dest
74 //dest can equal source
75 vms_vector *vm_vec_sub2(vms_vector *dest,vms_vector *src)
84 //averages two vectors. returns ptr to dest
85 //dest can equal either source
86 vms_vector *vm_vec_avg(vms_vector *dest,vms_vector *src0,vms_vector *src1)
88 dest->x = (src0->x + src1->x)/2;
89 dest->y = (src0->y + src1->y)/2;
90 dest->z = (src0->z + src1->z)/2;
96 //averages four vectors. returns ptr to dest
97 //dest can equal any source
98 vms_vector *vm_vec_avg4(vms_vector *dest,vms_vector *src0,vms_vector *src1,vms_vector *src2,vms_vector *src3)
100 dest->x = (src0->x + src1->x + src2->x + src3->x)/4;
101 dest->y = (src0->y + src1->y + src2->y + src3->y)/4;
102 dest->z = (src0->z + src1->z + src2->z + src3->z)/4;
108 //scales a vector in place. returns ptr to vector
109 vms_vector *vm_vec_scale(vms_vector *dest,fix s)
111 dest->x = fixmul(dest->x,s);
112 dest->y = fixmul(dest->y,s);
113 dest->z = fixmul(dest->z,s);
118 //scales and copies a vector. returns ptr to dest
119 vms_vector *vm_vec_copy_scale(vms_vector *dest,vms_vector *src,fix s)
121 dest->x = fixmul(src->x,s);
122 dest->y = fixmul(src->y,s);
123 dest->z = fixmul(src->z,s);
128 //scales a vector, adds it to another, and stores in a 3rd vector
129 //dest = src1 + k * src2
130 vms_vector *vm_vec_scale_add(vms_vector *dest,vms_vector *src1,vms_vector *src2,fix k)
132 dest->x = src1->x + fixmul(src2->x,k);
133 dest->y = src1->y + fixmul(src2->y,k);
134 dest->z = src1->z + fixmul(src2->z,k);
139 //scales a vector and adds it to another
141 vms_vector *vm_vec_scale_add2(vms_vector *dest,vms_vector *src,fix k)
143 dest->x += fixmul(src->x,k);
144 dest->y += fixmul(src->y,k);
145 dest->z += fixmul(src->z,k);
150 //scales a vector in place, taking n/d for scale. returns ptr to vector
152 vms_vector *vm_vec_scale2(vms_vector *dest,fix n,fix d)
154 #if 1 // DPH: Kludge: this was overflowing a lot, so I made it use the FPU.
156 // printf("scale n=%d d=%d\n",n,d);
157 nd = f2fl(n) / f2fl(d);
158 dest->x = fl2f( f2fl(dest->x) * nd);
159 dest->y = fl2f( f2fl(dest->y) * nd);
160 dest->z = fl2f( f2fl(dest->z) * nd);
162 dest->x = fixmuldiv(dest->x,n,d);
163 dest->y = fixmuldiv(dest->y,n,d);
164 dest->z = fixmuldiv(dest->z,n,d);
170 fix vm_vec_dotprod(vms_vector *v0,vms_vector *v1)
176 fixmulaccum(&q,v0->x,v1->x);
177 fixmulaccum(&q,v0->y,v1->y);
178 fixmulaccum(&q,v0->z,v1->z);
180 return fixquadadjust(&q);
183 fix vm_vec_dot3(fix x,fix y,fix z,vms_vector *v)
189 fixmulaccum(&q,x,v->x);
190 fixmulaccum(&q,y,v->y);
191 fixmulaccum(&q,z,v->z);
193 return fixquadadjust(&q);
196 //returns magnitude of a vector
197 fix vm_vec_mag(vms_vector *v)
203 fixmulaccum(&q,v->x,v->x);
204 fixmulaccum(&q,v->y,v->y);
205 fixmulaccum(&q,v->z,v->z);
207 return quad_sqrt(q.low,q.high);
210 //computes the distance between two points. (does sub and mag)
211 fix vm_vec_dist(vms_vector *v0,vms_vector *v1)
215 vm_vec_sub(&t,v0,v1);
217 return vm_vec_mag(&t);
221 //computes an approximation of the magnitude of the vector
222 //uses dist = largest + next_largest*3/8 + smallest*3/16
223 fix vm_vec_mag_quick(vms_vector *v)
243 bc = (b>>2) + (c>>3);
245 return a + bc + (bc>>1);
249 //computes an approximation of the distance between two points.
250 //uses dist = largest + next_largest*3/8 + smallest*3/16
251 fix vm_vec_dist_quick(vms_vector *v0,vms_vector *v1)
255 vm_vec_sub(&t,v0,v1);
257 return vm_vec_mag_quick(&t);
260 //normalize a vector. returns mag of source vec
261 fix vm_vec_copy_normalize(vms_vector *dest,vms_vector *src)
268 dest->x = fixdiv(src->x,m);
269 dest->y = fixdiv(src->y,m);
270 dest->z = fixdiv(src->z,m);
276 //normalize a vector. returns mag of source vec
277 fix vm_vec_normalize(vms_vector *v)
279 return vm_vec_copy_normalize(v,v);
283 //normalize a vector. returns mag of source vec. uses approx mag
284 fix vm_vec_copy_normalize_quick(vms_vector *dest,vms_vector *src)
288 m = vm_vec_mag_quick(src);
291 dest->x = fixdiv(src->x,m);
292 dest->y = fixdiv(src->y,m);
293 dest->z = fixdiv(src->z,m);
300 //these routines use an approximation for 1/sqrt
302 //returns approximation of 1/magnitude of a vector
303 fix vm_vec_imag(vms_vector *v)
309 fixmulaccum(&q,v->x,v->x);
310 fixmulaccum(&q,v->y,v->y);
311 fixmulaccum(&q,v->z,v->z);
314 return fix_isqrt(fixquadadjust(&q));
315 else if (q.high >= 0x800000) {
316 return (fix_isqrt(q.high) >> 8);
319 return (fix_isqrt((q.high<<8) + (q.low>>24)) >> 4);
322 //normalize a vector. returns 1/mag of source vec. uses approx 1/mag
323 fix vm_vec_copy_normalize_quick(vms_vector *dest,vms_vector *src)
327 im = vm_vec_imag(src);
329 dest->x = fixmul(src->x,im);
330 dest->y = fixmul(src->y,im);
331 dest->z = fixmul(src->z,im);
338 //normalize a vector. returns 1/mag of source vec. uses approx 1/mag
339 fix vm_vec_normalize_quick(vms_vector *v)
341 return vm_vec_copy_normalize_quick(v,v);
344 //return the normalized direction vector between two points
345 //dest = normalized(end - start). Returns 1/mag of direction vector
346 //NOTE: the order of the parameters matches the vector subtraction
347 fix vm_vec_normalized_dir_quick(vms_vector *dest,vms_vector *end,vms_vector *start)
349 vm_vec_sub(dest,end,start);
351 return vm_vec_normalize_quick(dest);
354 //return the normalized direction vector between two points
355 //dest = normalized(end - start). Returns mag of direction vector
356 //NOTE: the order of the parameters matches the vector subtraction
357 fix vm_vec_normalized_dir(vms_vector *dest,vms_vector *end,vms_vector *start)
359 vm_vec_sub(dest,end,start);
361 return vm_vec_normalize(dest);
364 //computes surface normal from three points. result is normalized
365 //returns ptr to dest
366 //dest CANNOT equal either source
367 vms_vector *vm_vec_normal(vms_vector *dest,vms_vector *p0,vms_vector *p1,vms_vector *p2)
369 vm_vec_perp(dest,p0,p1,p2);
371 vm_vec_normalize(dest);
376 //make sure a vector is reasonably sized to go into a cross product
377 void check_vec(vms_vector *v)
382 check = labs(v->x) | labs(v->y) | labs(v->z);
387 if (check & 0xfffc0000) { //too big
389 while (check & 0xfff00000) {
394 while (check & 0xfffc0000) {
403 else //maybe too small
404 if ((check & 0xffff8000) == 0) { //yep, too small
406 while ((check & 0xfffff000) == 0) {
411 while ((check & 0xffff8000) == 0) {
422 //computes cross product of two vectors.
423 //Note: this magnitude of the resultant vector is the
424 //product of the magnitudes of the two source vectors. This means it is
425 //quite easy for this routine to overflow and underflow. Be careful that
426 //your inputs are ok.
429 vms_vector *vm_vec_crossprod(vms_vector *dest,vms_vector *src0,vms_vector *src1)
432 Assert(dest!=src0 && dest!=src1);
434 d = (double)(src0->y) * (double)(src1->z);
435 d += (double)-(src0->z) * (double)(src1->y);
441 d = (double)(src0->z) * (double)(src1->x);
442 d += (double)-(src0->x) * (double)(src1->z);
448 d = (double)(src0->x) * (double)(src1->y);
449 d += (double)-(src0->y) * (double)(src1->x);
459 vms_vector *vm_vec_crossprod(vms_vector *dest,vms_vector *src0,vms_vector *src1)
463 Assert(dest!=src0 && dest!=src1);
466 fixmulaccum(&q,src0->y,src1->z);
467 fixmulaccum(&q,-src0->z,src1->y);
468 dest->x = fixquadadjust(&q);
471 fixmulaccum(&q,src0->z,src1->x);
472 fixmulaccum(&q,-src0->x,src1->z);
473 dest->y = fixquadadjust(&q);
476 fixmulaccum(&q,src0->x,src1->y);
477 fixmulaccum(&q,-src0->y,src1->x);
478 dest->z = fixquadadjust(&q);
486 //computes non-normalized surface normal from three points.
487 //returns ptr to dest
488 //dest CANNOT equal either source
489 vms_vector *vm_vec_perp(vms_vector *dest,vms_vector *p0,vms_vector *p1,vms_vector *p2)
493 vm_vec_sub(&t0,p1,p0);
494 vm_vec_sub(&t1,p2,p1);
499 return vm_vec_crossprod(dest,&t0,&t1);
503 //computes the delta angle between two vectors.
504 //vectors need not be normalized. if they are, call vm_vec_delta_ang_norm()
505 //the forward vector (third parameter) can be NULL, in which case the absolute
506 //value of the angle in returned. Otherwise the angle around that vector is
508 fixang vm_vec_delta_ang(vms_vector *v0,vms_vector *v1,vms_vector *fvec)
512 vm_vec_copy_normalize(&t0,v0);
513 vm_vec_copy_normalize(&t1,v1);
515 return vm_vec_delta_ang_norm(&t0,&t1,fvec);
518 //computes the delta angle between two normalized vectors.
519 fixang vm_vec_delta_ang_norm(vms_vector *v0,vms_vector *v1,vms_vector *fvec)
523 a = fix_acos(vm_vec_dot(v0,v1));
528 vm_vec_cross(&t,v0,v1);
530 if (vm_vec_dot(&t,fvec) < 0)
537 vms_matrix *sincos_2_matrix(vms_matrix *m,fix sinp,fix cosp,fix sinb,fix cosb,fix sinh,fix cosh)
539 fix sbsh,cbch,cbsh,sbch;
541 sbsh = fixmul(sinb,sinh);
542 cbch = fixmul(cosb,cosh);
543 cbsh = fixmul(cosb,sinh);
544 sbch = fixmul(sinb,cosh);
546 m->rvec.x = cbch + fixmul(sinp,sbsh); //m1
547 m->uvec.z = sbsh + fixmul(sinp,cbch); //m8
549 m->uvec.x = fixmul(sinp,cbsh) - sbch; //m2
550 m->rvec.z = fixmul(sinp,sbch) - cbsh; //m7
552 m->fvec.x = fixmul(sinh,cosp); //m3
553 m->rvec.y = fixmul(sinb,cosp); //m4
554 m->uvec.y = fixmul(cosb,cosp); //m5
555 m->fvec.z = fixmul(cosh,cosp); //m9
557 m->fvec.y = -sinp; //m6
563 //computes a matrix from a set of three angles. returns ptr to matrix
564 vms_matrix *vm_angles_2_matrix(vms_matrix *m,vms_angvec *a)
566 fix sinp,cosp,sinb,cosb,sinh,cosh;
568 fix_sincos(a->p,&sinp,&cosp);
569 fix_sincos(a->b,&sinb,&cosb);
570 fix_sincos(a->h,&sinh,&cosh);
572 return sincos_2_matrix(m,sinp,cosp,sinb,cosb,sinh,cosh);
576 //computes a matrix from a forward vector and an angle
577 vms_matrix *vm_vec_ang_2_matrix(vms_matrix *m,vms_vector *v,fixang a)
579 fix sinb,cosb,sinp,cosp,sinh,cosh;
581 fix_sincos(a,&sinb,&cosb);
584 cosp = fix_sqrt(f1_0 - fixmul(sinp,sinp));
586 sinh = fixdiv(v->x,cosp);
587 cosh = fixdiv(v->z,cosp);
589 return sincos_2_matrix(m,sinp,cosp,sinb,cosb,sinh,cosh);
593 //computes a matrix from one or more vectors. The forward vector is required,
594 //with the other two being optional. If both up & right vectors are passed,
595 //the up vector is used. If only the forward vector is passed, a bank of
597 //returns ptr to matrix
598 vms_matrix *vm_vector_2_matrix(vms_matrix *m,vms_vector *fvec,vms_vector *uvec,vms_vector *rvec)
600 vms_vector *xvec=&m->rvec,*yvec=&m->uvec,*zvec=&m->fvec;
602 Assert(fvec != NULL);
604 if (vm_vec_copy_normalize(zvec,fvec) == 0) {
605 Int3(); //forward vec should not be zero-length
611 if (rvec == NULL) { //just forward vec
616 if (zvec->x==0 && zvec->z==0) { //forward vec is straight up or down
619 m->uvec.z = (zvec->y<0)?f1_0:-f1_0;
621 m->rvec.y = m->rvec.z = m->uvec.x = m->uvec.y = 0;
623 else { //not straight up or down
629 vm_vec_normalize(xvec);
631 vm_vec_crossprod(yvec,zvec,xvec);
636 else { //use right vec
638 if (vm_vec_copy_normalize(xvec,rvec) == 0)
641 vm_vec_crossprod(yvec,zvec,xvec);
643 //normalize new perpendicular vector
644 if (vm_vec_normalize(yvec) == 0)
647 //now recompute right vector, in case it wasn't entirely perpendiclar
648 vm_vec_crossprod(xvec,yvec,zvec);
654 if (vm_vec_copy_normalize(yvec,uvec) == 0)
657 vm_vec_crossprod(xvec,yvec,zvec);
659 //normalize new perpendicular vector
660 if (vm_vec_normalize(xvec) == 0)
663 //now recompute up vector, in case it wasn't entirely perpendiclar
664 vm_vec_crossprod(yvec,zvec,xvec);
672 //quicker version of vm_vector_2_matrix() that takes normalized vectors
673 vms_matrix *vm_vector_2_matrix_norm(vms_matrix *m,vms_vector *fvec,vms_vector *uvec,vms_vector *rvec)
675 vms_vector *xvec=&m->rvec,*yvec=&m->uvec,*zvec=&m->fvec;
677 Assert(fvec != NULL);
681 if (rvec == NULL) { //just forward vec
686 if (zvec->x==0 && zvec->z==0) { //forward vec is straight up or down
689 m->uvec.z = (zvec->y<0)?f1_0:-f1_0;
691 m->rvec.y = m->rvec.z = m->uvec.x = m->uvec.y = 0;
693 else { //not straight up or down
699 vm_vec_normalize(xvec);
701 vm_vec_crossprod(yvec,zvec,xvec);
706 else { //use right vec
708 vm_vec_crossprod(yvec,zvec,xvec);
710 //normalize new perpendicular vector
711 if (vm_vec_normalize(yvec) == 0)
714 //now recompute right vector, in case it wasn't entirely perpendiclar
715 vm_vec_crossprod(xvec,yvec,zvec);
721 vm_vec_crossprod(xvec,yvec,zvec);
723 //normalize new perpendicular vector
724 if (vm_vec_normalize(xvec) == 0)
727 //now recompute up vector, in case it wasn't entirely perpendiclar
728 vm_vec_crossprod(yvec,zvec,xvec);
736 //rotates a vector through a matrix. returns ptr to dest vector
737 //dest CANNOT equal source
738 vms_vector *vm_vec_rotate(vms_vector *dest,vms_vector *src,vms_matrix *m)
742 dest->x = vm_vec_dot(src,&m->rvec);
743 dest->y = vm_vec_dot(src,&m->uvec);
744 dest->z = vm_vec_dot(src,&m->fvec);
750 //transpose a matrix in place. returns ptr to matrix
751 vms_matrix *vm_transpose_matrix(vms_matrix *m)
755 t = m->uvec.x; m->uvec.x = m->rvec.y; m->rvec.y = t;
756 t = m->fvec.x; m->fvec.x = m->rvec.z; m->rvec.z = t;
757 t = m->fvec.y; m->fvec.y = m->uvec.z; m->uvec.z = t;
762 //copy and transpose a matrix. returns ptr to matrix
763 //dest CANNOT equal source. use vm_transpose_matrix() if this is the case
764 vms_matrix *vm_copy_transpose_matrix(vms_matrix *dest,vms_matrix *src)
768 dest->rvec.x = src->rvec.x;
769 dest->rvec.y = src->uvec.x;
770 dest->rvec.z = src->fvec.x;
772 dest->uvec.x = src->rvec.y;
773 dest->uvec.y = src->uvec.y;
774 dest->uvec.z = src->fvec.y;
776 dest->fvec.x = src->rvec.z;
777 dest->fvec.y = src->uvec.z;
778 dest->fvec.z = src->fvec.z;
783 //mulitply 2 matrices, fill in dest. returns ptr to dest
784 //dest CANNOT equal either source
785 vms_matrix *vm_matrix_x_matrix(vms_matrix *dest,vms_matrix *src0,vms_matrix *src1)
787 Assert(dest!=src0 && dest!=src1);
789 dest->rvec.x = vm_vec_dot3(src0->rvec.x,src0->uvec.x,src0->fvec.x, &src1->rvec);
790 dest->uvec.x = vm_vec_dot3(src0->rvec.x,src0->uvec.x,src0->fvec.x, &src1->uvec);
791 dest->fvec.x = vm_vec_dot3(src0->rvec.x,src0->uvec.x,src0->fvec.x, &src1->fvec);
793 dest->rvec.y = vm_vec_dot3(src0->rvec.y,src0->uvec.y,src0->fvec.y, &src1->rvec);
794 dest->uvec.y = vm_vec_dot3(src0->rvec.y,src0->uvec.y,src0->fvec.y, &src1->uvec);
795 dest->fvec.y = vm_vec_dot3(src0->rvec.y,src0->uvec.y,src0->fvec.y, &src1->fvec);
797 dest->rvec.z = vm_vec_dot3(src0->rvec.z,src0->uvec.z,src0->fvec.z, &src1->rvec);
798 dest->uvec.z = vm_vec_dot3(src0->rvec.z,src0->uvec.z,src0->fvec.z, &src1->uvec);
799 dest->fvec.z = vm_vec_dot3(src0->rvec.z,src0->uvec.z,src0->fvec.z, &src1->fvec);
806 //extract angles from a matrix
807 vms_angvec *vm_extract_angles_matrix(vms_angvec *a,vms_matrix *m)
811 if (m->fvec.x==0 && m->fvec.z==0) //zero head
814 a->h = fix_atan2(m->fvec.z,m->fvec.x);
816 fix_sincos(a->h,&sinh,&cosh);
818 if (abs(sinh) > abs(cosh)) //sine is larger, so use it
819 cosp = fixdiv(m->fvec.x,sinh);
820 else //cosine is larger, so use it
821 cosp = fixdiv(m->fvec.z,cosh);
823 if (cosp==0 && m->fvec.y==0)
826 a->p = fix_atan2(cosp,-m->fvec.y);
829 if (cosp == 0) //the cosine of pitch is zero. we're pitched straight up. say no bank
836 sinb = fixdiv(m->rvec.y,cosp);
837 cosb = fixdiv(m->uvec.y,cosp);
839 if (sinb==0 && cosb==0)
842 a->b = fix_atan2(cosb,sinb);
850 //extract heading and pitch from a vector, assuming bank==0
851 vms_angvec *vm_extract_angles_vector_normalized(vms_angvec *a,vms_vector *v)
853 a->b = 0; //always zero bank
855 a->p = fix_asin(-v->y);
857 if (v->x==0 && v->z==0)
860 a->h = fix_atan2(v->z,v->x);
865 //extract heading and pitch from a vector, assuming bank==0
866 vms_angvec *vm_extract_angles_vector(vms_angvec *a,vms_vector *v)
870 if (vm_vec_copy_normalize(&t,v) != 0)
871 vm_extract_angles_vector_normalized(a,&t);
877 //compute the distance from a point to a plane. takes the normalized normal
878 //of the plane (ebx), a point on the plane (edi), and the point to check (esi).
879 //returns distance in eax
880 //distance is signed, so negative dist is on the back of the plane
881 fix vm_dist_to_plane(vms_vector *checkp,vms_vector *norm,vms_vector *planep)
885 vm_vec_sub(&t,checkp,planep);
887 return vm_vec_dot(&t,norm);
891 vms_vector *vm_vec_make(vms_vector *v,fix x,fix y,fix z)
893 v->x=x; v->y=y; v->z=z;