2 * $Logfile: /Freespace2/code/Object/ObjCollide.cpp $
7 * Helper routines for all the collision detection functions
8 * Also keeps track of all the object pairs.
11 * Revision 1.2 2002/05/07 03:16:48 theoddone33
12 * The Great Newline Fix
14 * Revision 1.1.1.1 2002/05/03 03:28:10 root
18 * 18 7/15/99 9:20a Andsager
19 * FS2_DEMO initial checkin
21 * 17 6/14/99 3:21p Andsager
22 * Allow collisions between ship and its debris. Fix up collision pairs
23 * when large ship is warping out.
25 * 16 5/08/99 8:25p Dave
26 * Upped object pairs. First run of nebula lightning.
28 * 15 4/23/99 12:01p Johnson
31 * 14 4/21/99 6:15p Dave
32 * Did some serious housecleaning in the beam code. Made it ready to go
33 * for anti-fighter "pulse" weapons. Fixed collision pair creation. Added
34 * a handy macro for recalculating collision pairs for a given object.
36 * 13 4/20/99 3:41p Andsager
37 * Modify objects_will_collide to use endpoints
39 * 12 3/10/99 6:50p Dave
40 * Changed the way we buffer packets for all clients. Optimized turret
41 * fired packets. Did some weapon firing optimizations.
43 * 11 3/05/99 3:32p Dan
44 * Make out of collision pars message npirntf with "collision"
46 * 10 1/21/99 2:06p Dave
47 * Final checkin for multiplayer testing.
49 * 9 1/21/99 10:44a Dave
50 * More beam weapon stuff. Put in warmdown time.
52 * 8 1/15/99 5:01p Dave
53 * Fix for object collision problem.
55 * 7 1/12/99 5:45p Dave
56 * Moved weapon pipeline in multiplayer to almost exclusively client side.
57 * Very good results. Bandwidth goes down, playability goes up for crappy
58 * connections. Fixed object update problem for ship subsystems.
60 * 6 1/12/99 12:53a Dave
61 * More work on beam weapons - made collision detection very efficient -
62 * collide against all object types properly - made 3 movement types
63 * smooth. Put in test code to check for possible non-darkening pixels on
66 * 5 11/19/98 11:08p Andsager
67 * Check in of physics and collision detection of rotating submodels
69 * 4 11/05/98 5:55p Dave
70 * Big pass at reducing #includes
72 * 3 10/26/98 9:42a Dave
73 * Early flak gun support.
75 * 2 10/07/98 10:53a Dave
78 * 1 10/07/98 10:50a Dave
80 * 38 7/29/98 3:24p Allender
81 * don't call collision code when either of the object pairs is NULL.
83 * 37 4/08/98 8:38a Mike
84 * Make ships avoid player when attacking or guarding a faraway object.
86 * 36 4/02/98 11:40a Lawrance
87 * check for #ifdef DEMO instead of #ifdef DEMO_RELEASE
89 * 35 4/01/98 1:48p Allender
90 * major changes to ship collision in multiplayer. Clients now do own
91 * ship/ship collisions (with their own ship only) Modifed the hull
92 * update packet to be sent quicker when object is target of player.
94 * 34 4/01/98 10:57a Mike
95 * Reduce array sizes to save memory.
97 * 33 3/31/98 5:18p John
98 * Removed demo/save/restore. Made NDEBUG defined compile. Removed a
99 * bunch of debug stuff out of player file. Made model code be able to
100 * unload models and malloc out only however many models are needed.
103 * 32 3/06/98 12:45a Lawrance
104 * Rmove a bogus assert in the object pair save/restore
106 * 31 3/05/98 3:12p Mike
107 * Fix bugs in asteroid collisions. Throw asteroids at Galataea (needs to
108 * be made general). Add skill level support for asteroid throwing.
110 * 30 3/05/98 12:12a Mike
111 * Make an asteroid in the way prevent player warpout.
113 * 29 2/27/98 4:48p John
114 * Made objects keep track of number of pairs they have associated with
115 * them. Then, I can early out of the obj_remove_all which was 2.5% of
116 * frametime at beginning of sm2-2 which then is 0% after this.
118 * 28 2/26/98 10:07p Hoffoss
119 * Rewrote state saving and restoring to fix bugs and simplify the code.
121 * 27 2/23/98 9:00a Andsager
122 * improved back face culling of object:laser pairs to check relative
123 * velocity dot laser forward < 0 vs. v_other dot v_laser < 0
125 * 26 2/19/98 4:34p Lawrance
126 * Allow weapon-asteroid collisions
128 * 25 2/19/98 10:52a Sandeep
129 * AL: Have asteroids collide with all ships
131 * 24 2/12/98 11:45a Andsager
132 * Try to cull debris:weapon collisions before they collisoin pair is
133 * created. Look at movement in lifetime and whether debris is behind
136 * 23 2/07/98 3:54p John
137 * Added FVI to show_game_resources
139 * 22 2/06/98 7:29p John
140 * Made only players ships and player ship weapons do collisions with
143 * 21 2/05/98 11:49p Andsager
144 * Don't check laser:ship collisions on same team for small ships if laser
147 * 20 2/05/98 9:21p John
148 * Some new Direct3D code. Added code to monitor a ton of stuff in the
151 * 19 2/05/98 12:51a Mike
152 * Early asteroid stuff.
154 * 18 2/03/98 9:40a Andsager
155 * Modify collision object pair creation code so that pairs between debris
156 * and weapons (other than player) are not created.
158 * 17 1/28/98 11:06a Andsager
159 * Remove some collision pairs. Add debug code for displaying collision
162 * 16 1/24/98 11:16a Andsager
165 * 15 1/24/98 11:09a Andsager
166 * Fixed bug that was removing collision pairs when weapon within the
169 * 14 1/23/98 5:07p Andsager
170 * Added tests for object pairs. (1) for weapons that do not turn, find
171 * the soonest hit time. (2) Check if soonest hit time if after end of
174 * 13 1/22/98 6:43p John
175 * Took out debug code.
177 * 12 1/22/98 6:42p John
178 * Move game_flush out of debug console into freespace. Made object
179 * pair code throw out some weapons that turn. Added stats for how many
180 * object pair are actually checked.
182 * 11 1/17/98 10:06p Lawrance
183 * For missiles, only collide if WIF_BOMB flag set.
185 * 10 1/14/98 5:21p Allender
186 * system to delete object when buffer is nearly full. System in place to
187 * delete weapons when nearly out of weapons slots
189 * 9 1/13/98 8:09p John
190 * Removed the old collision system that checked all pairs. Added code
191 * to disable collisions and particles.
193 * 8 1/13/98 3:11p Allender
194 * new code to remove old weapons when no more weapon slots available.
195 * Currently not called anywhere pending further testing
197 * 7 1/10/98 3:22p Allender
198 * temporary check in to get new code
200 * 6 1/10/98 1:14p John
201 * Added explanation to debug console commands
203 * 5 1/09/98 9:29a Mike
204 * Enable docked ships to warp out. Make damage done to a ship not
205 * proportional to its own mass.
207 * 4 1/08/98 12:12a Mike
208 * Make ships turn before warping out, if necessary, to avoid a collision.
209 * Warn player if his warpout will collide. Abort if in stage1.
211 * 3 12/21/97 4:33p John
212 * Made debug console functions a class that registers itself
213 * automatically, so you don't need to add the function to
214 * debugfunctions.cpp.
216 * 2 12/16/97 5:23p Allender
217 * don't deal with object collision paris on multiplayer clients
219 * 1 9/17/97 2:14p John
225 #include "objcollide.h"
226 #include "linklist.h"
227 #include "systemvars.h"
233 #define MAX_PAIRS 3000
235 #define MAX_PAIRS 8000 // Reduced from 10,000 to 6,000 by MK on 4/1/98.
236 // Most I saw was 3400 in sm1-06a, the asteriod mission. No other mission came close.
239 // the next 3 variables are used for pair statistics
240 // also in weapon.cpp there is Weapons_created.
241 int Pairs_created = 0;
243 int Num_pairs_checked = 0;
244 int pairs_not_created = 0;
246 int Num_pairs_hwm = 0;
248 obj_pair Obj_pairs[MAX_PAIRS];
250 obj_pair pair_used_list;
251 obj_pair pair_free_list;
253 void obj_reset_pairs()
257 // mprintf(( "Resetting object pairs...\n" ));
259 pair_used_list.a = pair_used_list.b = NULL;
260 pair_used_list.next = NULL;
261 pair_free_list.a = pair_free_list.b = NULL;
262 pair_free_list.next = &Obj_pairs[0];
265 for (i=0; i<MAX_PAIRS; i++ ) {
266 Obj_pairs[i].a = Obj_pairs[i].b = NULL;
267 Obj_pairs[i].next = &Obj_pairs[i+1];
269 Obj_pairs[MAX_PAIRS-1].next = NULL;
272 // returns true if we should reject object pair if one is child of other.
273 int reject_obj_pair_on_parent(object *A, object *B)
275 if (A->type == OBJ_SHIP) {
276 if (B->type == OBJ_DEBRIS) {
277 if (B->parent_sig == A->signature) {
283 if (B->type == OBJ_SHIP) {
284 if (A->type == OBJ_DEBRIS) {
285 if (A->parent_sig == B->signature) {
291 if (A->parent_sig == B->signature) {
295 if (B->parent_sig == A->signature) {
303 // Adds the pair to the pair list
304 void obj_add_pair( object *A, object *B, int check_time, int add_to_end )
307 int (*check_collision)( obj_pair *pair );
310 check_collision = NULL;
312 if ( A==B ) return; // Don't check collisions with yourself
314 if ( !(A->flags&OF_COLLIDES) ) return; // This object doesn't collide with anything
315 if ( !(B->flags&OF_COLLIDES) ) return; // This object doesn't collide with anything
317 // Make sure you're not checking a parent with it's kid or vicy-versy
318 // if ( A->parent_sig == B->signature && !(A->type == OBJ_SHIP && B->type == OBJ_DEBRIS) ) return;
319 // if ( B->parent_sig == A->signature && !(A->type == OBJ_DEBRIS && B->type == OBJ_SHIP) ) return;
320 if ( reject_obj_pair_on_parent(A,B) ) {
324 Assert( A->type < 127 );
325 Assert( B->type < 127 );
327 ctype = COLLISION_OF(A->type,B->type);
329 case COLLISION_OF(OBJ_WEAPON,OBJ_SHIP):
331 check_collision = collide_ship_weapon;
333 case COLLISION_OF(OBJ_SHIP, OBJ_WEAPON):
334 check_collision = collide_ship_weapon;
336 case COLLISION_OF(OBJ_DEBRIS, OBJ_WEAPON):
337 check_collision = collide_debris_weapon;
339 case COLLISION_OF(OBJ_WEAPON, OBJ_DEBRIS):
341 check_collision = collide_debris_weapon;
343 case COLLISION_OF(OBJ_DEBRIS, OBJ_SHIP):
344 check_collision = collide_debris_ship;
346 case COLLISION_OF(OBJ_SHIP, OBJ_DEBRIS):
347 check_collision = collide_debris_ship;
350 case COLLISION_OF(OBJ_ASTEROID, OBJ_WEAPON):
351 // Only check collision's with player weapons
352 // if ( Objects[B->parent].flags & OF_PLAYER_SHIP ) {
353 check_collision = collide_asteroid_weapon;
356 case COLLISION_OF(OBJ_WEAPON, OBJ_ASTEROID):
358 // Only check collision's with player weapons
359 // if ( Objects[A->parent].flags & OF_PLAYER_SHIP ) {
360 check_collision = collide_asteroid_weapon;
363 case COLLISION_OF(OBJ_ASTEROID, OBJ_SHIP):
364 // Only check collisions with player ships
365 // if ( B->flags & OF_PLAYER_SHIP ) {
366 check_collision = collide_asteroid_ship;
369 case COLLISION_OF(OBJ_SHIP, OBJ_ASTEROID):
370 // Only check collisions with player ships
371 // if ( A->flags & OF_PLAYER_SHIP ) {
372 check_collision = collide_asteroid_ship;
376 case COLLISION_OF(OBJ_SHIP,OBJ_SHIP):
377 check_collision = collide_ship_ship;
380 case COLLISION_OF(OBJ_BEAM, OBJ_SHIP):
381 if(beam_collide_early_out(A, B)){
384 check_collision = beam_collide_ship;
387 case COLLISION_OF(OBJ_BEAM, OBJ_ASTEROID):
388 if(beam_collide_early_out(A, B)){
391 check_collision = beam_collide_asteroid;
394 case COLLISION_OF(OBJ_BEAM, OBJ_DEBRIS):
395 if(beam_collide_early_out(A, B)){
398 check_collision = beam_collide_debris;
401 case COLLISION_OF(OBJ_BEAM, OBJ_WEAPON):
402 if(beam_collide_early_out(A, B)){
405 check_collision = beam_collide_missile;
408 case COLLISION_OF(OBJ_WEAPON, OBJ_WEAPON): {
409 weapon_info *awip, *bwip;
410 awip = &Weapon_info[Weapons[A->instance].weapon_info_index];
411 bwip = &Weapon_info[Weapons[B->instance].weapon_info_index];
413 if (awip->subtype != WP_LASER || bwip->subtype != WP_LASER) {
414 if (awip->subtype == WP_LASER) {
415 if ( bwip->wi_flags & WIF_BOMB ) {
416 check_collision = collide_weapon_weapon;
418 } else if (bwip->subtype == WP_LASER) {
419 if ( awip->wi_flags & WIF_BOMB ) {
420 check_collision = collide_weapon_weapon;
424 if ( (awip->wi_flags&WIF_BOMB) || (bwip->wi_flags&WIF_BOMB) ) {
425 check_collision = collide_weapon_weapon;
432 atype = Weapon_info[Weapons[A->instance].weapon_info_index].subtype;
433 btype = Weapon_info[Weapons[B->instance].weapon_info_index].subtype;
435 if ((atype == WP_LASER) && (btype == WP_MISSILE))
436 check_collision = collide_weapon_weapon;
437 else if ((atype == WP_MISSILE) && (btype == WP_LASER)) {
438 check_collision = collide_weapon_weapon;
440 } else if ((atype == WP_MISSILE) && (btype == WP_MISSILE))
441 check_collision = collide_weapon_weapon;
451 // Swap them if needed
458 // if there are any more obj_pair checks
459 // we should then add function int maybe_not_add_obj_pair()
460 // MWA -- 4/1/98 -- I'd do it, but I don't want to bust anything, so I'm doing my stuff here instead :-)
461 //if ( MULTIPLAYER_CLIENT && !(Netgame.debug_flags & NETD_FLAG_CLIENT_NODAMAGE)){
462 // multiplayer clients will only do ship/ship collisions, and their own ship to boot
463 // if ( check_collision != collide_ship_ship ){
467 // if ( (A != Player_obj) && (B != Player_obj) ){
472 // only check debris:weapon collisions for player
473 if (check_collision == collide_debris_weapon) {
475 if ( !(Weapon_info[Weapons[B->instance].weapon_info_index].wi_flags & WIF_TURNS) ) {
476 // check for dumbfire weapon
477 // check if debris is behind laser
479 if (Weapon_info[Weapons[B->instance].weapon_info_index].subtype == WP_LASER) {
480 vector velocity_rel_weapon;
481 vm_vec_sub(&velocity_rel_weapon, &B->phys_info.vel, &A->phys_info.vel);
482 vdot = -vm_vec_dot(&velocity_rel_weapon, &B->orient.fvec);
484 vdot = vm_vec_dot( &A->phys_info.vel, &B->phys_info.vel);
486 if ( vdot <= 0.0f ) {
487 // They're heading in opposite directions...
488 // check their positions
490 vm_vec_sub( &weapon2other, &A->pos, &B->pos );
491 float pdot = vm_vec_dot( &B->orient.fvec, &weapon2other );
492 if ( pdot <= -A->radius ) {
493 // The other object is behind the weapon by more than
494 // its radius, so it will never hit...
499 // check dist vs. dist moved during weapon lifetime
501 vm_vec_sub(&delta_v, &B->phys_info.vel, &A->phys_info.vel);
502 if (vm_vec_dist_squared(&A->pos, &B->pos) > (vm_vec_mag_squared(&delta_v)*Weapons[B->instance].lifeleft*Weapons[B->instance].lifeleft)) {
506 // for nonplayer ships, only create collision pair if close enough
507 if ( !(Objects[B->parent].flags & OF_PLAYER_SHIP) && (vm_vec_dist(&B->pos, &A->pos) < (4.0f*A->radius + 200.0f)) )
512 // don't check same team laser:ship collisions on small ships if not player
513 if (check_collision == collide_ship_weapon) {
515 if ( !(Objects[B->parent].flags & OF_PLAYER_SHIP)
516 && (Ships[Objects[B->parent].instance].team == Ships[A->instance].team)
517 && (Ship_info[Ships[A->instance].ship_info_index].flags & SIF_SMALL_SHIP)
518 && (Weapon_info[Weapons[B->instance].weapon_info_index].subtype == WP_LASER) ) {
524 if ( !check_collision ) return;
527 // At this point, we have determined that collisions between
528 // these two should be checked, so add the pair to the
529 // collision pair list.
531 if ( pair_free_list.next == NULL ) {
532 nprintf(( "collision", "Out of object pairs!! Not all collisions will work!\n" ));
536 // get a new obj_pair from the free list
537 obj_pair * new_pair = pair_free_list.next;
538 pair_free_list.next = new_pair->next;
541 obj_pair *last, *tmp;
543 last = tmp = pair_used_list.next;
544 while( tmp != NULL ) {
545 if ( tmp->next == NULL )
552 last = &pair_used_list;
554 last->next = new_pair;
555 Assert(new_pair != NULL);
556 new_pair->next = NULL;
559 new_pair->next = pair_used_list.next;
560 pair_used_list.next = new_pair;
564 /* if (Num_pairs > Num_pairs_hwm) {
565 Num_pairs_hwm = Num_pairs;
566 //nprintf(("AI", "Num_pairs high water mark = %i\n", Num_pairs_hwm));
575 new_pair->check_collision = check_collision;
577 if ( check_time == -1 ){
578 new_pair->next_check_time = timestamp(0); // 0 means instantly time out
580 new_pair->next_check_time = check_time;
586 MONITOR(NumPairsChecked);
588 void obj_check_all_collisions()
590 if ( !(Game_detail_flags & DETAIL_FLAG_COLLISION) ) return;
592 obj_pair *parent, *tmp;
594 float avg_time_to_next_check = 0.0f;
596 parent = &pair_used_list;
599 Num_pairs_checked = 0;
601 while( tmp != NULL ) {
604 if ( (tmp->a != NULL) && (tmp->b != NULL) && timestamp_elapsed(tmp->next_check_time) ) {
607 if ((*tmp->check_collision)(tmp)) {
608 // We never need to check this pair again.
609 #if 0 //def DONT_REMOVE_PAIRS
610 // Never check it again, but keep the pair around
611 // (useful for debugging)
612 tmp->next_check_time = timestamp(-1);
614 // Never check it again, so remove the pair
617 Assert( tmp->a->num_pairs > -1 );
619 Assert( tmp->b->num_pairs > -1 );
621 // Assert(Num_pairs >= 0);
622 parent->next = tmp->next;
623 tmp->a = tmp->b = NULL;
624 tmp->next = pair_free_list.next;
625 pair_free_list.next = tmp;
636 int add_time = timestamp_until( tmp->next_check_time );
638 avg_time_to_next_check += (float) add_time;
643 MONITOR_INC(NumPairs,Num_pairs);
644 MONITOR_INC(NumPairsChecked,Num_pairs_checked);
646 // #define PAIR_STATS
648 avg_time_to_next_check = avg_time_to_next_check / Num_pairs;
649 extern int Num_hull_pieces;
650 extern int Weapons_created;
651 // mprintf(( "[pairs checked: %d, start_pairs: %d, num obj: %d, avg next time: %f]\n", n, org_pairs, num_objects, avg_time_to_next_check ));
652 // mprintf(( "[Num_hull_pieces: %3d, Num_weapons_created: %3d, pairs_not_created: %3d, pairs_created: %3d, percent new saved: %9.5f]\n", Num_hull_pieces, Weapons_created, pairs_not_created, Pairs_created, 100.0f*(float)pairs_not_created/(float)(pairs_not_created + Pairs_created) ));
653 mprintf(( "[pairs_created: %3d, pairs_not_created: %3d, percent saved %6.3f]\n", Pairs_created, pairs_not_created, 100.0f*pairs_not_created/(Pairs_created+pairs_not_created) ));
654 pairs_not_created = 0;
659 // What percent of the pairs did we check?
660 // FYI: (n*(n-1))/2 is the total number of checks required for comparing n objects.
662 // if ( org_pairs > 1 ) {
663 // Object_checked_percentage = (i2fl(n)*100.0f) / i2fl(org_pairs);
665 // Object_checked_percentage = 0.0f;
670 // See if two lines intersect by doing recursive subdivision.
671 // Bails out if larger distance traveled is less than sum of radii + 1.0f.
672 int collide_subdivide(vector *p0, vector *p1, float prad, vector *q0, vector *q1, float qrad)
674 float a_dist, b_dist, ab_dist;
676 a_dist = vm_vec_dist(p0, p1);
677 b_dist = vm_vec_dist(q0, q1);
679 ab_dist = vm_vec_dist(p1, q1);
681 // See if their spheres intersect
682 if (ab_dist < a_dist + b_dist + prad + qrad) {
683 if (ab_dist < prad + qrad)
685 else if (vm_vec_dist(p0, q0) < prad + qrad)
687 else if (max(a_dist, b_dist) < prad + qrad + 1.0f)
693 vm_vec_avg(&pa, p0, p1);
694 vm_vec_avg(&qa, q0, q1);
695 r1 = collide_subdivide(p0, &pa, prad, q0, &qa, qrad);
697 r2 = collide_subdivide(&pa, p1, prad, &qa, q1, qrad);
707 // Return true if object A is expected to collide with object B within time duration
708 // For purposes of this check, the first object moves from current location to predicted
709 // location. The second object is assumed to be where it will be at time duration, NOT
710 // where it currently is.
711 // radius_scale is used to control the precision of the check.
712 // If 0.0, then use polygon models to perform check, slow and accurate
713 // If !0.0, then use as a scale on the radius of the objects. 1.0 is Descent style
714 // collisions. Larger values can be used to be sloppy about the collisions which
715 // is useful if a moving object wants to prevent a collision.
716 int objects_will_collide(object *A, object *B, float duration, float radius_scale)
723 vm_vec_scale_add2(&A_future.pos, &A->phys_info.vel, duration);
725 if (radius_scale == 0.0f) {
726 return ship_check_collision_fast(B, &A_future, &hitpos );
728 float size_A, size_B, dist, r;
729 vector nearest_point;
731 size_A = A->radius * radius_scale;
732 size_B = B->radius * radius_scale;
734 // If A is moving, check along vector.
735 if (A->phys_info.speed != 0.0f) {
736 r = find_nearest_point_on_line(&nearest_point, &A->pos, &A_future.pos, &B->pos);
738 nearest_point = A->pos;
740 nearest_point = A_future.pos;
742 dist = vm_vec_dist_quick(&B->pos, &nearest_point);
743 return (dist < size_A + size_B);
745 return vm_vec_dist_quick(&B->pos, &A->pos) < size_A + size_B;
750 // Return true if the vector from *start_pos to *end_pos is within objp->radius*radius_scale of *objp
751 int vector_object_collision(vector *start_pos, vector *end_pos, object *objp, float radius_scale)
754 vector nearest_point;
756 r = find_nearest_point_on_line(&nearest_point, start_pos, end_pos, &objp->pos);
757 if ((r >= 0.0f) && (r <= 1.0f)) {
758 dist = vm_vec_dist_quick(&objp->pos, &nearest_point);
760 return (dist < objp->radius * radius_scale);
765 // Returns TRUE if the weapon will never hit the other object.
766 // If it can it predicts how long until these two objects need
767 // to be checked and fills the time in in current_pair.
768 int weapon_will_never_hit( object *weapon, object *other, obj_pair * current_pair )
771 Assert( weapon->type == OBJ_WEAPON );
773 // mprintf(( "Frame: %d, Weapon=%d, Other=%d, pair=$%08x\n", G3_frame_count, OBJ_INDEX(weapon), OBJ_INDEX(other), current_pair ));
776 // Do some checks for weapons that don't turn
777 if ( !(Weapon_info[Weapons[weapon->instance].weapon_info_index].wi_flags & WIF_TURNS) ) {
779 // This first check is to see if a weapon is behind an object, and they
780 // are heading in opposite directions. If so, we don't need to ever check
781 // them again. This is only valid for weapons that don't turn.
784 if (Weapon_info[Weapons[weapon->instance].weapon_info_index].subtype == WP_LASER) {
785 vector velocity_rel_weapon;
786 vm_vec_sub(&velocity_rel_weapon, &weapon->phys_info.vel, &other->phys_info.vel);
787 vdot = -vm_vec_dot(&velocity_rel_weapon, &weapon->orient.fvec);
789 vdot = vm_vec_dot( &other->phys_info.vel, &weapon->phys_info.vel);
791 if ( vdot <= 0.0f ) {
792 // They're heading in opposite directions...
793 // check their positions
795 vm_vec_sub( &weapon2other, &other->pos, &weapon->pos );
796 float pdot = vm_vec_dot( &weapon->orient.fvec, &weapon2other );
797 if ( pdot <= -other->radius ) {
798 // The other object is behind the weapon by more than
799 // its radius, so it will never hit...
804 // FUTURE ENHANCEMENT IDEAS
806 // Given a laser does it hit a slow or not moving object
807 // in its life or the next n seconds? We'd actually need to check the
813 // This check doesn't care about orient, only looks at the maximum speed
814 // of the two objects, so it knows that in the next n seconds, they can't
815 // go further than some distance, so don't bother checking collisions for
816 // that time. This is very rough, but is so general that it works for
817 // everything and immidiately gets rid of a lot of cases.
819 if ( current_pair ) {
820 // Find the time it will take before these get within each others distances.
821 // tmp->next_check_time = timestamp(500);
822 //vector max_vel; //maximum foward velocity in x,y,z
824 float max_vel_weapon, max_vel_other;
825 max_vel_weapon = weapon->phys_info.max_vel.z;
826 max_vel_other = other->phys_info.max_vel.z;
827 if (max_vel_other < 10.0f) {
828 if ( vm_vec_mag_squared( &other->phys_info.vel ) > 100 ) {
829 // bump up velocity from collision
830 max_vel_other = vm_vec_mag( &other->phys_info.vel ) + 10.0f;
832 max_vel_other = 10.0f; // object may move from collision
836 // check weapon that does not turn against sphere expanding at ship maxvel
837 // compare (weeapon) ray with expanding sphere (ship) to find earliest possible collision time
838 // look for two time solutions to Xw = Xs, where Xw = Xw0 + Vwt*t Xs = Xs + Vs*(t+dt), where Vs*dt = radius of ship
839 // Since direction of Vs is unknown, solve for (Vs*t) and find norm of both sides
840 if ( !(Weapon_info[Weapons[weapon->instance].weapon_info_index].wi_flags & WIF_TURNS) ) {
841 vector delta_x, laser_vel;
842 float a,b,c, delta_x_dot_vl, delta_t;
843 float root1, root2, root, earliest_time;
845 vm_vec_sub( &delta_x, &weapon->pos, &other->pos );
846 vm_vec_copy_scale( &laser_vel, &weapon->orient.fvec, max_vel_weapon );
847 delta_t = (other->radius + 10.0f) / max_vel_other; // time to get from center to radius of other obj
848 delta_x_dot_vl = vm_vec_dotprod( &delta_x, &laser_vel );
850 a = max_vel_weapon*max_vel_weapon - max_vel_other*max_vel_other;
851 b = 2.0f * (delta_x_dot_vl - max_vel_other*max_vel_other*delta_t);
852 c = vm_vec_mag_squared( &delta_x ) - max_vel_other*max_vel_other*delta_t*delta_t;
854 float discriminant = b*b - 4.0f*a*c;
855 if ( discriminant < 0) {
859 root = fl_sqrt( discriminant );
860 root1 = (-b + root) / (2.0f * a) * 1000.0f; // get time in ms
861 root2 = (-b - root) / (2.0f * a) * 1000.0f; // get time in ms
864 // find earliest positive time
865 if ( root1 > root2 ) {
872 earliest_time = root1;
873 } else if (root2 > 0) {
874 // root1 < 0 and root2 > 0, so we're inside sphere and next check should be next frame
875 current_pair->next_check_time = timestamp(0); // check next time
878 // both times negative, so never collides
884 // check if possible collision occurs after weapon expires
885 if ( earliest_time > 1000*Weapons[weapon->instance].lifeleft )
888 // Allow one worst case frametime to elapse (~5 fps)
889 earliest_time -= 200.0f;
891 if (earliest_time > 100) {
892 current_pair->next_check_time = timestamp( fl2i(earliest_time) );
895 current_pair->next_check_time = timestamp(0); // check next time
901 float dist, max_vel, time;
903 max_vel = max_vel_weapon + max_vel_other;
905 // suggest that fudge factor for other radius be changed to other_radius + const (~10)
906 dist = vm_vec_dist( &other->pos, &weapon->pos ) - (other->radius + 10.0f);
908 time = (dist*1000.0f) / max_vel;
909 int time_ms = fl2i(time);
911 // check if possible collision occurs after weapon expires
912 if ( time_ms > 1000*Weapons[weapon->instance].lifeleft )
915 time_ms -= 200; // Allow at least one worst case frametime to elapse (~5 fps)
917 if ( time_ms > 100 ) { // If it takes longer than 1/10th of a second, then delay it
918 current_pair->next_check_time = timestamp(time_ms);
919 //mprintf(( "Delaying %d ms\n", time_ms ));
923 current_pair->next_check_time = timestamp(0); // check next time
931 // Return true if vector from *curpos to *goalpos intersects with object *goalobjp
932 // Else, return false.
933 // radius is radius of object moving from curpos to goalpos.
934 int pp_collide(vector *curpos, vector *goalpos, object *goalobjp, float radius)
938 Assert(goalobjp->type == OBJ_SHIP);
940 ship_model_start(goalobjp);
942 mc.model_num = Ships[goalobjp->instance].modelnum; // Fill in the model to check
943 mc.orient = &goalobjp->orient; // The object's orient
944 mc.pos = &goalobjp->pos; // The object's position
945 mc.p0 = curpos; // Point 1 of ray to check
946 mc.p1 = goalpos; // Point 2 of ray to check
947 mc.flags = MC_CHECK_MODEL | MC_CHECK_SPHERELINE;
952 ship_model_stop(goalobjp);
957 // Setup and call pp_collide for collide_predict_large_ship
958 // Returns true if objp will collide with objp2 before it reaches goal_pos.
959 int cpls_aux(vector *goal_pos, object *objp2, object *objp)
963 radius = objp->radius;
964 if (1.5f * radius < 70.0f)
969 if (pp_collide(&objp->pos, goal_pos, objp2, radius))
975 // Return true if objp will collide with some large object.
976 // Don't check for an object this ship is docked to.
977 int collide_predict_large_ship(object *objp, float distance)
980 vector cur_pos, goal_pos;
984 sip = &Ship_info[Ships[objp->instance].ship_info_index];
987 if (objp->type == OBJ_SHIP) {
988 ai_info *aip = &Ai_info[Ships[objp->instance].ai_index];
989 if (aip->dock_objnum != -1)
990 dock_objp = &Objects[aip->dock_objnum];
995 vm_vec_scale_add(&goal_pos, &cur_pos, &objp->orient.fvec, distance);
997 for ( objp2 = GET_FIRST(&obj_used_list); objp2 != END_OF_LIST(&obj_used_list); objp2 = GET_NEXT(objp2) ) {
998 if ((objp != objp2) && (objp2->type == OBJ_SHIP)) {
999 if (Ship_info[Ships[objp2->instance].ship_info_index].flags & (SIF_BIG_SHIP | SIF_HUGE_SHIP)) {
1000 if (objp2 == dock_objp)
1003 if (cpls_aux(&goal_pos, objp2, objp))
1006 } else if (!(sip->flags & (SIF_BIG_SHIP | SIF_HUGE_SHIP)) && (objp2->type == OBJ_ASTEROID)) {
1007 if (vm_vec_dist_quick(&objp2->pos, &objp->pos) < (distance + objp2->radius)*2.5f) {
1012 d1 = 2.5f * distance + objp2->radius;
1013 count = (int) (d1/(objp2->radius + objp->radius)); // Scale up distance, else looks like there would be a collision.
1015 vm_vec_normalized_dir(&delvec, &goal_pos, &cur_pos);
1016 vm_vec_scale(&delvec, d1/count);
1018 for (; count>0; count--) {
1019 if (vm_vec_dist_quick(&pos, &objp2->pos) < objp->radius + objp2->radius)
1021 vm_vec_add2(&pos, &delvec);
1030 // function to iterate through all object collision pairs looking for weapons
1031 // which could be deleted since they are not going to hit anything. Passed into this
1032 // function is a 'time' parameter used as watermark for which weapons to check.
1034 #define CRW_NO_OBJECT -1
1035 #define CRW_NO_PAIR 0
1036 #define CRW_IN_PAIR 1
1037 #define CRW_CAN_DELETE 2
1039 #define CRW_MAX_TO_DELETE 4
1041 char crw_status[MAX_WEAPONS];
1043 void crw_check_weapon( int weapon_num, int collide_next_check )
1045 float next_check_time;
1048 wp = &Weapons[weapon_num];
1050 // if this weapons life left > time before next collision, then we cannot remove it
1051 crw_status[WEAPON_INDEX(wp)] = CRW_IN_PAIR;
1052 next_check_time = ((float)(timestamp_until(collide_next_check)) / 1000.0f);
1053 if ( wp->lifeleft < next_check_time )
1054 crw_status[WEAPON_INDEX(wp)] = CRW_CAN_DELETE;
1057 int collide_remove_weapons( )
1060 int i, num_deleted, oldest_index, j, loop_count;
1063 // setup remove_weapon array. assume we can remove it.
1064 for (i = 0; i < MAX_WEAPONS; i++ ) {
1065 if ( Weapons[i].objnum == -1 )
1066 crw_status[i] = CRW_NO_OBJECT;
1068 crw_status[i] = CRW_NO_PAIR;
1071 // first pass is to see if any of the weapons don't have collision pairs.
1073 opp = &pair_used_list;
1075 while( opp != NULL ) {
1076 // for each collide pair, if the two objects can still collide, then set the remove_weapon
1077 // parameter for the weapon to 0. need to check both parameters
1078 if ( opp->a->type == OBJ_WEAPON )
1079 crw_check_weapon( opp->a->instance, opp->next_check_time );
1081 if ( opp->b->type == OBJ_WEAPON )
1082 crw_check_weapon( opp->b->instance, opp->next_check_time );
1087 // for each weapon which could be removed, delete the object
1089 for ( i = 0; i < MAX_WEAPONS; i++ ) {
1090 if ( crw_status[i] == CRW_CAN_DELETE ) {
1091 Assert( Weapons[i].objnum != -1 );
1092 obj_delete( Weapons[i].objnum );
1100 // if we didn't remove any weapons, try to the N oldest weapons. first checking for pairs, then
1101 // checking for oldest weapons in general. We will go through the loop a max of 2 times. first time
1102 // through, we check oldest weapons with pairs, next time through, for oldest weapons.
1105 for ( j = 0; j < CRW_MAX_TO_DELETE; j++ ) {
1106 oldest_time = 1000.0f;
1108 for (i = 0; i < MAX_WEAPONS; i++ ) {
1109 if ( Weapons[i].objnum == -1 ) // shouldn't happen, but this is the safe thing to do.
1111 if ( ((loop_count || crw_status[i] == CRW_NO_PAIR)) && (Weapons[i].lifeleft < oldest_time) ) {
1112 oldest_time = Weapons[i].lifeleft;
1116 if ( oldest_index != -1 ) {
1117 obj_delete(Weapons[oldest_index].objnum);
1122 // if we deleted some weapons, then we can break
1127 } while ( loop_count < 2);
1133 void set_hit_struct_info(collision_info_struct *hit, mc_info *mc, int submodel_rot_hit)
1135 hit->edge_hit = mc->edge_hit;
1136 hit->hit_pos = mc->hit_point_world;
1137 hit->hit_time = mc->hit_dist;
1138 hit->submodel_num = mc->hit_submodel;
1140 hit->submodel_rot_hit = submodel_rot_hit;