2 * Copyright (C) Volition, Inc. 1999. All rights reserved.
4 * All source code herein is the property of Volition, Inc. You may not sell
5 * or otherwise commercially exploit the source or things you created based on
10 * $Logfile: /Freespace2/code/Object/ObjCollide.cpp $
15 * Helper routines for all the collision detection functions
16 * Also keeps track of all the object pairs.
19 * Revision 1.4 2002/06/17 06:33:10 relnev
20 * ryan's struct patch for gcc 2.95
22 * Revision 1.3 2002/06/09 04:41:24 relnev
23 * added copyright header
25 * Revision 1.2 2002/05/07 03:16:48 theoddone33
26 * The Great Newline Fix
28 * Revision 1.1.1.1 2002/05/03 03:28:10 root
32 * 18 7/15/99 9:20a Andsager
33 * FS2_DEMO initial checkin
35 * 17 6/14/99 3:21p Andsager
36 * Allow collisions between ship and its debris. Fix up collision pairs
37 * when large ship is warping out.
39 * 16 5/08/99 8:25p Dave
40 * Upped object pairs. First run of nebula lightning.
42 * 15 4/23/99 12:01p Johnson
45 * 14 4/21/99 6:15p Dave
46 * Did some serious housecleaning in the beam code. Made it ready to go
47 * for anti-fighter "pulse" weapons. Fixed collision pair creation. Added
48 * a handy macro for recalculating collision pairs for a given object.
50 * 13 4/20/99 3:41p Andsager
51 * Modify objects_will_collide to use endpoints
53 * 12 3/10/99 6:50p Dave
54 * Changed the way we buffer packets for all clients. Optimized turret
55 * fired packets. Did some weapon firing optimizations.
57 * 11 3/05/99 3:32p Dan
58 * Make out of collision pars message npirntf with "collision"
60 * 10 1/21/99 2:06p Dave
61 * Final checkin for multiplayer testing.
63 * 9 1/21/99 10:44a Dave
64 * More beam weapon stuff. Put in warmdown time.
66 * 8 1/15/99 5:01p Dave
67 * Fix for object collision problem.
69 * 7 1/12/99 5:45p Dave
70 * Moved weapon pipeline in multiplayer to almost exclusively client side.
71 * Very good results. Bandwidth goes down, playability goes up for crappy
72 * connections. Fixed object update problem for ship subsystems.
74 * 6 1/12/99 12:53a Dave
75 * More work on beam weapons - made collision detection very efficient -
76 * collide against all object types properly - made 3 movement types
77 * smooth. Put in test code to check for possible non-darkening pixels on
80 * 5 11/19/98 11:08p Andsager
81 * Check in of physics and collision detection of rotating submodels
83 * 4 11/05/98 5:55p Dave
84 * Big pass at reducing #includes
86 * 3 10/26/98 9:42a Dave
87 * Early flak gun support.
89 * 2 10/07/98 10:53a Dave
92 * 1 10/07/98 10:50a Dave
94 * 38 7/29/98 3:24p Allender
95 * don't call collision code when either of the object pairs is NULL.
97 * 37 4/08/98 8:38a Mike
98 * Make ships avoid player when attacking or guarding a faraway object.
100 * 36 4/02/98 11:40a Lawrance
101 * check for #ifdef DEMO instead of #ifdef DEMO_RELEASE
103 * 35 4/01/98 1:48p Allender
104 * major changes to ship collision in multiplayer. Clients now do own
105 * ship/ship collisions (with their own ship only) Modifed the hull
106 * update packet to be sent quicker when object is target of player.
108 * 34 4/01/98 10:57a Mike
109 * Reduce array sizes to save memory.
111 * 33 3/31/98 5:18p John
112 * Removed demo/save/restore. Made NDEBUG defined compile. Removed a
113 * bunch of debug stuff out of player file. Made model code be able to
114 * unload models and malloc out only however many models are needed.
117 * 32 3/06/98 12:45a Lawrance
118 * Rmove a bogus assert in the object pair save/restore
120 * 31 3/05/98 3:12p Mike
121 * Fix bugs in asteroid collisions. Throw asteroids at Galataea (needs to
122 * be made general). Add skill level support for asteroid throwing.
124 * 30 3/05/98 12:12a Mike
125 * Make an asteroid in the way prevent player warpout.
127 * 29 2/27/98 4:48p John
128 * Made objects keep track of number of pairs they have associated with
129 * them. Then, I can early out of the obj_remove_all which was 2.5% of
130 * frametime at beginning of sm2-2 which then is 0% after this.
132 * 28 2/26/98 10:07p Hoffoss
133 * Rewrote state saving and restoring to fix bugs and simplify the code.
135 * 27 2/23/98 9:00a Andsager
136 * improved back face culling of object:laser pairs to check relative
137 * velocity dot laser forward < 0 vs. v_other dot v_laser < 0
139 * 26 2/19/98 4:34p Lawrance
140 * Allow weapon-asteroid collisions
142 * 25 2/19/98 10:52a Sandeep
143 * AL: Have asteroids collide with all ships
145 * 24 2/12/98 11:45a Andsager
146 * Try to cull debris:weapon collisions before they collisoin pair is
147 * created. Look at movement in lifetime and whether debris is behind
150 * 23 2/07/98 3:54p John
151 * Added FVI to show_game_resources
153 * 22 2/06/98 7:29p John
154 * Made only players ships and player ship weapons do collisions with
157 * 21 2/05/98 11:49p Andsager
158 * Don't check laser:ship collisions on same team for small ships if laser
161 * 20 2/05/98 9:21p John
162 * Some new Direct3D code. Added code to monitor a ton of stuff in the
165 * 19 2/05/98 12:51a Mike
166 * Early asteroid stuff.
168 * 18 2/03/98 9:40a Andsager
169 * Modify collision object pair creation code so that pairs between debris
170 * and weapons (other than player) are not created.
172 * 17 1/28/98 11:06a Andsager
173 * Remove some collision pairs. Add debug code for displaying collision
176 * 16 1/24/98 11:16a Andsager
179 * 15 1/24/98 11:09a Andsager
180 * Fixed bug that was removing collision pairs when weapon within the
183 * 14 1/23/98 5:07p Andsager
184 * Added tests for object pairs. (1) for weapons that do not turn, find
185 * the soonest hit time. (2) Check if soonest hit time if after end of
188 * 13 1/22/98 6:43p John
189 * Took out debug code.
191 * 12 1/22/98 6:42p John
192 * Move game_flush out of debug console into freespace. Made object
193 * pair code throw out some weapons that turn. Added stats for how many
194 * object pair are actually checked.
196 * 11 1/17/98 10:06p Lawrance
197 * For missiles, only collide if WIF_BOMB flag set.
199 * 10 1/14/98 5:21p Allender
200 * system to delete object when buffer is nearly full. System in place to
201 * delete weapons when nearly out of weapons slots
203 * 9 1/13/98 8:09p John
204 * Removed the old collision system that checked all pairs. Added code
205 * to disable collisions and particles.
207 * 8 1/13/98 3:11p Allender
208 * new code to remove old weapons when no more weapon slots available.
209 * Currently not called anywhere pending further testing
211 * 7 1/10/98 3:22p Allender
212 * temporary check in to get new code
214 * 6 1/10/98 1:14p John
215 * Added explanation to debug console commands
217 * 5 1/09/98 9:29a Mike
218 * Enable docked ships to warp out. Make damage done to a ship not
219 * proportional to its own mass.
221 * 4 1/08/98 12:12a Mike
222 * Make ships turn before warping out, if necessary, to avoid a collision.
223 * Warn player if his warpout will collide. Abort if in stage1.
225 * 3 12/21/97 4:33p John
226 * Made debug console functions a class that registers itself
227 * automatically, so you don't need to add the function to
228 * debugfunctions.cpp.
230 * 2 12/16/97 5:23p Allender
231 * don't deal with object collision paris on multiplayer clients
233 * 1 9/17/97 2:14p John
239 #include "objcollide.h"
240 #include "linklist.h"
241 #include "systemvars.h"
247 #define MAX_PAIRS 3000
249 #define MAX_PAIRS 8000 // Reduced from 10,000 to 6,000 by MK on 4/1/98.
250 // Most I saw was 3400 in sm1-06a, the asteriod mission. No other mission came close.
253 // the next 3 variables are used for pair statistics
254 // also in weapon.cpp there is Weapons_created.
255 int Pairs_created = 0;
257 int Num_pairs_checked = 0;
258 int pairs_not_created = 0;
260 int Num_pairs_hwm = 0;
262 obj_pair Obj_pairs[MAX_PAIRS];
264 obj_pair pair_used_list;
265 obj_pair pair_free_list;
267 void obj_reset_pairs()
271 // mprintf(( "Resetting object pairs...\n" ));
273 pair_used_list.a = pair_used_list.b = NULL;
274 pair_used_list.next = NULL;
275 pair_free_list.a = pair_free_list.b = NULL;
276 pair_free_list.next = &Obj_pairs[0];
279 for (i=0; i<MAX_PAIRS; i++ ) {
280 Obj_pairs[i].a = Obj_pairs[i].b = NULL;
281 Obj_pairs[i].next = &Obj_pairs[i+1];
283 Obj_pairs[MAX_PAIRS-1].next = NULL;
286 // returns true if we should reject object pair if one is child of other.
287 int reject_obj_pair_on_parent(object *A, object *B)
289 if (A->type == OBJ_SHIP) {
290 if (B->type == OBJ_DEBRIS) {
291 if (B->parent_sig == A->signature) {
297 if (B->type == OBJ_SHIP) {
298 if (A->type == OBJ_DEBRIS) {
299 if (A->parent_sig == B->signature) {
305 if (A->parent_sig == B->signature) {
309 if (B->parent_sig == A->signature) {
317 // Adds the pair to the pair list
318 void obj_add_pair( object *A, object *B, int check_time, int add_to_end )
321 int (*check_collision)( obj_pair *pair );
324 check_collision = NULL;
326 if ( A==B ) return; // Don't check collisions with yourself
328 if ( !(A->flags&OF_COLLIDES) ) return; // This object doesn't collide with anything
329 if ( !(B->flags&OF_COLLIDES) ) return; // This object doesn't collide with anything
331 // Make sure you're not checking a parent with it's kid or vicy-versy
332 // if ( A->parent_sig == B->signature && !(A->type == OBJ_SHIP && B->type == OBJ_DEBRIS) ) return;
333 // if ( B->parent_sig == A->signature && !(A->type == OBJ_DEBRIS && B->type == OBJ_SHIP) ) return;
334 if ( reject_obj_pair_on_parent(A,B) ) {
338 Assert( A->type < 127 );
339 Assert( B->type < 127 );
341 ctype = COLLISION_OF(A->type,B->type);
343 case COLLISION_OF(OBJ_WEAPON,OBJ_SHIP):
345 check_collision = collide_ship_weapon;
347 case COLLISION_OF(OBJ_SHIP, OBJ_WEAPON):
348 check_collision = collide_ship_weapon;
350 case COLLISION_OF(OBJ_DEBRIS, OBJ_WEAPON):
351 check_collision = collide_debris_weapon;
353 case COLLISION_OF(OBJ_WEAPON, OBJ_DEBRIS):
355 check_collision = collide_debris_weapon;
357 case COLLISION_OF(OBJ_DEBRIS, OBJ_SHIP):
358 check_collision = collide_debris_ship;
360 case COLLISION_OF(OBJ_SHIP, OBJ_DEBRIS):
361 check_collision = collide_debris_ship;
364 case COLLISION_OF(OBJ_ASTEROID, OBJ_WEAPON):
365 // Only check collision's with player weapons
366 // if ( Objects[B->parent].flags & OF_PLAYER_SHIP ) {
367 check_collision = collide_asteroid_weapon;
370 case COLLISION_OF(OBJ_WEAPON, OBJ_ASTEROID):
372 // Only check collision's with player weapons
373 // if ( Objects[A->parent].flags & OF_PLAYER_SHIP ) {
374 check_collision = collide_asteroid_weapon;
377 case COLLISION_OF(OBJ_ASTEROID, OBJ_SHIP):
378 // Only check collisions with player ships
379 // if ( B->flags & OF_PLAYER_SHIP ) {
380 check_collision = collide_asteroid_ship;
383 case COLLISION_OF(OBJ_SHIP, OBJ_ASTEROID):
384 // Only check collisions with player ships
385 // if ( A->flags & OF_PLAYER_SHIP ) {
386 check_collision = collide_asteroid_ship;
390 case COLLISION_OF(OBJ_SHIP,OBJ_SHIP):
391 check_collision = collide_ship_ship;
394 case COLLISION_OF(OBJ_BEAM, OBJ_SHIP):
395 if(beam_collide_early_out(A, B)){
398 check_collision = beam_collide_ship;
401 case COLLISION_OF(OBJ_BEAM, OBJ_ASTEROID):
402 if(beam_collide_early_out(A, B)){
405 check_collision = beam_collide_asteroid;
408 case COLLISION_OF(OBJ_BEAM, OBJ_DEBRIS):
409 if(beam_collide_early_out(A, B)){
412 check_collision = beam_collide_debris;
415 case COLLISION_OF(OBJ_BEAM, OBJ_WEAPON):
416 if(beam_collide_early_out(A, B)){
419 check_collision = beam_collide_missile;
422 case COLLISION_OF(OBJ_WEAPON, OBJ_WEAPON): {
423 weapon_info *awip, *bwip;
424 awip = &Weapon_info[Weapons[A->instance].weapon_info_index];
425 bwip = &Weapon_info[Weapons[B->instance].weapon_info_index];
427 if (awip->subtype != WP_LASER || bwip->subtype != WP_LASER) {
428 if (awip->subtype == WP_LASER) {
429 if ( bwip->wi_flags & WIF_BOMB ) {
430 check_collision = collide_weapon_weapon;
432 } else if (bwip->subtype == WP_LASER) {
433 if ( awip->wi_flags & WIF_BOMB ) {
434 check_collision = collide_weapon_weapon;
438 if ( (awip->wi_flags&WIF_BOMB) || (bwip->wi_flags&WIF_BOMB) ) {
439 check_collision = collide_weapon_weapon;
446 atype = Weapon_info[Weapons[A->instance].weapon_info_index].subtype;
447 btype = Weapon_info[Weapons[B->instance].weapon_info_index].subtype;
449 if ((atype == WP_LASER) && (btype == WP_MISSILE))
450 check_collision = collide_weapon_weapon;
451 else if ((atype == WP_MISSILE) && (btype == WP_LASER)) {
452 check_collision = collide_weapon_weapon;
454 } else if ((atype == WP_MISSILE) && (btype == WP_MISSILE))
455 check_collision = collide_weapon_weapon;
465 // Swap them if needed
472 // if there are any more obj_pair checks
473 // we should then add function int maybe_not_add_obj_pair()
474 // MWA -- 4/1/98 -- I'd do it, but I don't want to bust anything, so I'm doing my stuff here instead :-)
475 //if ( MULTIPLAYER_CLIENT && !(Netgame.debug_flags & NETD_FLAG_CLIENT_NODAMAGE)){
476 // multiplayer clients will only do ship/ship collisions, and their own ship to boot
477 // if ( check_collision != collide_ship_ship ){
481 // if ( (A != Player_obj) && (B != Player_obj) ){
486 // only check debris:weapon collisions for player
487 if (check_collision == collide_debris_weapon) {
489 if ( !(Weapon_info[Weapons[B->instance].weapon_info_index].wi_flags & WIF_TURNS) ) {
490 // check for dumbfire weapon
491 // check if debris is behind laser
493 if (Weapon_info[Weapons[B->instance].weapon_info_index].subtype == WP_LASER) {
494 vector velocity_rel_weapon;
495 vm_vec_sub(&velocity_rel_weapon, &B->phys_info.vel, &A->phys_info.vel);
496 vdot = -vm_vec_dot(&velocity_rel_weapon, &B->orient.v.fvec);
498 vdot = vm_vec_dot( &A->phys_info.vel, &B->phys_info.vel);
500 if ( vdot <= 0.0f ) {
501 // They're heading in opposite directions...
502 // check their positions
504 vm_vec_sub( &weapon2other, &A->pos, &B->pos );
505 float pdot = vm_vec_dot( &B->orient.v.fvec, &weapon2other );
506 if ( pdot <= -A->radius ) {
507 // The other object is behind the weapon by more than
508 // its radius, so it will never hit...
513 // check dist vs. dist moved during weapon lifetime
515 vm_vec_sub(&delta_v, &B->phys_info.vel, &A->phys_info.vel);
516 if (vm_vec_dist_squared(&A->pos, &B->pos) > (vm_vec_mag_squared(&delta_v)*Weapons[B->instance].lifeleft*Weapons[B->instance].lifeleft)) {
520 // for nonplayer ships, only create collision pair if close enough
521 if ( !(Objects[B->parent].flags & OF_PLAYER_SHIP) && (vm_vec_dist(&B->pos, &A->pos) < (4.0f*A->radius + 200.0f)) )
526 // don't check same team laser:ship collisions on small ships if not player
527 if (check_collision == collide_ship_weapon) {
529 if ( !(Objects[B->parent].flags & OF_PLAYER_SHIP)
530 && (Ships[Objects[B->parent].instance].team == Ships[A->instance].team)
531 && (Ship_info[Ships[A->instance].ship_info_index].flags & SIF_SMALL_SHIP)
532 && (Weapon_info[Weapons[B->instance].weapon_info_index].subtype == WP_LASER) ) {
538 if ( !check_collision ) return;
541 // At this point, we have determined that collisions between
542 // these two should be checked, so add the pair to the
543 // collision pair list.
545 if ( pair_free_list.next == NULL ) {
546 nprintf(( "collision", "Out of object pairs!! Not all collisions will work!\n" ));
550 // get a new obj_pair from the free list
551 obj_pair * new_pair = pair_free_list.next;
552 pair_free_list.next = new_pair->next;
555 obj_pair *last, *tmp;
557 last = tmp = pair_used_list.next;
558 while( tmp != NULL ) {
559 if ( tmp->next == NULL )
566 last = &pair_used_list;
568 last->next = new_pair;
569 Assert(new_pair != NULL);
570 new_pair->next = NULL;
573 new_pair->next = pair_used_list.next;
574 pair_used_list.next = new_pair;
578 /* if (Num_pairs > Num_pairs_hwm) {
579 Num_pairs_hwm = Num_pairs;
580 //nprintf(("AI", "Num_pairs high water mark = %i\n", Num_pairs_hwm));
589 new_pair->check_collision = check_collision;
591 if ( check_time == -1 ){
592 new_pair->next_check_time = timestamp(0); // 0 means instantly time out
594 new_pair->next_check_time = check_time;
600 MONITOR(NumPairsChecked);
602 void obj_check_all_collisions()
604 if ( !(Game_detail_flags & DETAIL_FLAG_COLLISION) ) return;
606 obj_pair *parent, *tmp;
608 float avg_time_to_next_check = 0.0f;
610 parent = &pair_used_list;
613 Num_pairs_checked = 0;
615 while( tmp != NULL ) {
618 if ( (tmp->a != NULL) && (tmp->b != NULL) && timestamp_elapsed(tmp->next_check_time) ) {
621 if ((*tmp->check_collision)(tmp)) {
622 // We never need to check this pair again.
623 #if 0 //def DONT_REMOVE_PAIRS
624 // Never check it again, but keep the pair around
625 // (useful for debugging)
626 tmp->next_check_time = timestamp(-1);
628 // Never check it again, so remove the pair
631 Assert( tmp->a->num_pairs > -1 );
633 Assert( tmp->b->num_pairs > -1 );
635 // Assert(Num_pairs >= 0);
636 parent->next = tmp->next;
637 tmp->a = tmp->b = NULL;
638 tmp->next = pair_free_list.next;
639 pair_free_list.next = tmp;
650 int add_time = timestamp_until( tmp->next_check_time );
652 avg_time_to_next_check += (float) add_time;
657 MONITOR_INC(NumPairs,Num_pairs);
658 MONITOR_INC(NumPairsChecked,Num_pairs_checked);
660 // #define PAIR_STATS
662 avg_time_to_next_check = avg_time_to_next_check / Num_pairs;
663 extern int Num_hull_pieces;
664 extern int Weapons_created;
665 // 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 ));
666 // 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) ));
667 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) ));
668 pairs_not_created = 0;
673 // What percent of the pairs did we check?
674 // FYI: (n*(n-1))/2 is the total number of checks required for comparing n objects.
676 // if ( org_pairs > 1 ) {
677 // Object_checked_percentage = (i2fl(n)*100.0f) / i2fl(org_pairs);
679 // Object_checked_percentage = 0.0f;
684 // See if two lines intersect by doing recursive subdivision.
685 // Bails out if larger distance traveled is less than sum of radii + 1.0f.
686 int collide_subdivide(vector *p0, vector *p1, float prad, vector *q0, vector *q1, float qrad)
688 float a_dist, b_dist, ab_dist;
690 a_dist = vm_vec_dist(p0, p1);
691 b_dist = vm_vec_dist(q0, q1);
693 ab_dist = vm_vec_dist(p1, q1);
695 // See if their spheres intersect
696 if (ab_dist < a_dist + b_dist + prad + qrad) {
697 if (ab_dist < prad + qrad)
699 else if (vm_vec_dist(p0, q0) < prad + qrad)
701 else if (max(a_dist, b_dist) < prad + qrad + 1.0f)
707 vm_vec_avg(&pa, p0, p1);
708 vm_vec_avg(&qa, q0, q1);
709 r1 = collide_subdivide(p0, &pa, prad, q0, &qa, qrad);
711 r2 = collide_subdivide(&pa, p1, prad, &qa, q1, qrad);
721 // Return true if object A is expected to collide with object B within time duration
722 // For purposes of this check, the first object moves from current location to predicted
723 // location. The second object is assumed to be where it will be at time duration, NOT
724 // where it currently is.
725 // radius_scale is used to control the precision of the check.
726 // If 0.0, then use polygon models to perform check, slow and accurate
727 // If !0.0, then use as a scale on the radius of the objects. 1.0 is Descent style
728 // collisions. Larger values can be used to be sloppy about the collisions which
729 // is useful if a moving object wants to prevent a collision.
730 int objects_will_collide(object *A, object *B, float duration, float radius_scale)
737 vm_vec_scale_add2(&A_future.pos, &A->phys_info.vel, duration);
739 if (radius_scale == 0.0f) {
740 return ship_check_collision_fast(B, &A_future, &hitpos );
742 float size_A, size_B, dist, r;
743 vector nearest_point;
745 size_A = A->radius * radius_scale;
746 size_B = B->radius * radius_scale;
748 // If A is moving, check along vector.
749 if (A->phys_info.speed != 0.0f) {
750 r = find_nearest_point_on_line(&nearest_point, &A->pos, &A_future.pos, &B->pos);
752 nearest_point = A->pos;
754 nearest_point = A_future.pos;
756 dist = vm_vec_dist_quick(&B->pos, &nearest_point);
757 return (dist < size_A + size_B);
759 return vm_vec_dist_quick(&B->pos, &A->pos) < size_A + size_B;
764 // Return true if the vector from *start_pos to *end_pos is within objp->radius*radius_scale of *objp
765 int vector_object_collision(vector *start_pos, vector *end_pos, object *objp, float radius_scale)
768 vector nearest_point;
770 r = find_nearest_point_on_line(&nearest_point, start_pos, end_pos, &objp->pos);
771 if ((r >= 0.0f) && (r <= 1.0f)) {
772 dist = vm_vec_dist_quick(&objp->pos, &nearest_point);
774 return (dist < objp->radius * radius_scale);
779 // Returns TRUE if the weapon will never hit the other object.
780 // If it can it predicts how long until these two objects need
781 // to be checked and fills the time in in current_pair.
782 int weapon_will_never_hit( object *weapon, object *other, obj_pair * current_pair )
785 Assert( weapon->type == OBJ_WEAPON );
787 // mprintf(( "Frame: %d, Weapon=%d, Other=%d, pair=$%08x\n", G3_frame_count, OBJ_INDEX(weapon), OBJ_INDEX(other), current_pair ));
790 // Do some checks for weapons that don't turn
791 if ( !(Weapon_info[Weapons[weapon->instance].weapon_info_index].wi_flags & WIF_TURNS) ) {
793 // This first check is to see if a weapon is behind an object, and they
794 // are heading in opposite directions. If so, we don't need to ever check
795 // them again. This is only valid for weapons that don't turn.
798 if (Weapon_info[Weapons[weapon->instance].weapon_info_index].subtype == WP_LASER) {
799 vector velocity_rel_weapon;
800 vm_vec_sub(&velocity_rel_weapon, &weapon->phys_info.vel, &other->phys_info.vel);
801 vdot = -vm_vec_dot(&velocity_rel_weapon, &weapon->orient.v.fvec);
803 vdot = vm_vec_dot( &other->phys_info.vel, &weapon->phys_info.vel);
805 if ( vdot <= 0.0f ) {
806 // They're heading in opposite directions...
807 // check their positions
809 vm_vec_sub( &weapon2other, &other->pos, &weapon->pos );
810 float pdot = vm_vec_dot( &weapon->orient.v.fvec, &weapon2other );
811 if ( pdot <= -other->radius ) {
812 // The other object is behind the weapon by more than
813 // its radius, so it will never hit...
818 // FUTURE ENHANCEMENT IDEAS
820 // Given a laser does it hit a slow or not moving object
821 // in its life or the next n seconds? We'd actually need to check the
827 // This check doesn't care about orient, only looks at the maximum speed
828 // of the two objects, so it knows that in the next n seconds, they can't
829 // go further than some distance, so don't bother checking collisions for
830 // that time. This is very rough, but is so general that it works for
831 // everything and immidiately gets rid of a lot of cases.
833 if ( current_pair ) {
834 // Find the time it will take before these get within each others distances.
835 // tmp->next_check_time = timestamp(500);
836 //vector max_vel; //maximum foward velocity in x,y,z
838 float max_vel_weapon, max_vel_other;
839 max_vel_weapon = weapon->phys_info.max_vel.xyz.z;
840 max_vel_other = other->phys_info.max_vel.xyz.z;
841 if (max_vel_other < 10.0f) {
842 if ( vm_vec_mag_squared( &other->phys_info.vel ) > 100 ) {
843 // bump up velocity from collision
844 max_vel_other = vm_vec_mag( &other->phys_info.vel ) + 10.0f;
846 max_vel_other = 10.0f; // object may move from collision
850 // check weapon that does not turn against sphere expanding at ship maxvel
851 // compare (weeapon) ray with expanding sphere (ship) to find earliest possible collision time
852 // look for two time solutions to Xw = Xs, where Xw = Xw0 + Vwt*t Xs = Xs + Vs*(t+dt), where Vs*dt = radius of ship
853 // Since direction of Vs is unknown, solve for (Vs*t) and find norm of both sides
854 if ( !(Weapon_info[Weapons[weapon->instance].weapon_info_index].wi_flags & WIF_TURNS) ) {
855 vector delta_x, laser_vel;
856 float a,b,c, delta_x_dot_vl, delta_t;
857 float root1, root2, root, earliest_time;
859 vm_vec_sub( &delta_x, &weapon->pos, &other->pos );
860 vm_vec_copy_scale( &laser_vel, &weapon->orient.v.fvec, max_vel_weapon );
861 delta_t = (other->radius + 10.0f) / max_vel_other; // time to get from center to radius of other obj
862 delta_x_dot_vl = vm_vec_dotprod( &delta_x, &laser_vel );
864 a = max_vel_weapon*max_vel_weapon - max_vel_other*max_vel_other;
865 b = 2.0f * (delta_x_dot_vl - max_vel_other*max_vel_other*delta_t);
866 c = vm_vec_mag_squared( &delta_x ) - max_vel_other*max_vel_other*delta_t*delta_t;
868 float discriminant = b*b - 4.0f*a*c;
869 if ( discriminant < 0) {
873 root = fl_sqrt( discriminant );
874 root1 = (-b + root) / (2.0f * a) * 1000.0f; // get time in ms
875 root2 = (-b - root) / (2.0f * a) * 1000.0f; // get time in ms
878 // find earliest positive time
879 if ( root1 > root2 ) {
886 earliest_time = root1;
887 } else if (root2 > 0) {
888 // root1 < 0 and root2 > 0, so we're inside sphere and next check should be next frame
889 current_pair->next_check_time = timestamp(0); // check next time
892 // both times negative, so never collides
898 // check if possible collision occurs after weapon expires
899 if ( earliest_time > 1000*Weapons[weapon->instance].lifeleft )
902 // Allow one worst case frametime to elapse (~5 fps)
903 earliest_time -= 200.0f;
905 if (earliest_time > 100) {
906 current_pair->next_check_time = timestamp( fl2i(earliest_time) );
909 current_pair->next_check_time = timestamp(0); // check next time
915 float dist, max_vel, time;
917 max_vel = max_vel_weapon + max_vel_other;
919 // suggest that fudge factor for other radius be changed to other_radius + const (~10)
920 dist = vm_vec_dist( &other->pos, &weapon->pos ) - (other->radius + 10.0f);
922 time = (dist*1000.0f) / max_vel;
923 int time_ms = fl2i(time);
925 // check if possible collision occurs after weapon expires
926 if ( time_ms > 1000*Weapons[weapon->instance].lifeleft )
929 time_ms -= 200; // Allow at least one worst case frametime to elapse (~5 fps)
931 if ( time_ms > 100 ) { // If it takes longer than 1/10th of a second, then delay it
932 current_pair->next_check_time = timestamp(time_ms);
933 //mprintf(( "Delaying %d ms\n", time_ms ));
937 current_pair->next_check_time = timestamp(0); // check next time
945 // Return true if vector from *curpos to *goalpos intersects with object *goalobjp
946 // Else, return false.
947 // radius is radius of object moving from curpos to goalpos.
948 int pp_collide(vector *curpos, vector *goalpos, object *goalobjp, float radius)
952 Assert(goalobjp->type == OBJ_SHIP);
954 ship_model_start(goalobjp);
956 mc.model_num = Ships[goalobjp->instance].modelnum; // Fill in the model to check
957 mc.orient = &goalobjp->orient; // The object's orient
958 mc.pos = &goalobjp->pos; // The object's position
959 mc.p0 = curpos; // Point 1 of ray to check
960 mc.p1 = goalpos; // Point 2 of ray to check
961 mc.flags = MC_CHECK_MODEL | MC_CHECK_SPHERELINE;
966 ship_model_stop(goalobjp);
971 // Setup and call pp_collide for collide_predict_large_ship
972 // Returns true if objp will collide with objp2 before it reaches goal_pos.
973 int cpls_aux(vector *goal_pos, object *objp2, object *objp)
977 radius = objp->radius;
978 if (1.5f * radius < 70.0f)
983 if (pp_collide(&objp->pos, goal_pos, objp2, radius))
989 // Return true if objp will collide with some large object.
990 // Don't check for an object this ship is docked to.
991 int collide_predict_large_ship(object *objp, float distance)
994 vector cur_pos, goal_pos;
998 sip = &Ship_info[Ships[objp->instance].ship_info_index];
1001 if (objp->type == OBJ_SHIP) {
1002 ai_info *aip = &Ai_info[Ships[objp->instance].ai_index];
1003 if (aip->dock_objnum != -1)
1004 dock_objp = &Objects[aip->dock_objnum];
1007 cur_pos = objp->pos;
1009 vm_vec_scale_add(&goal_pos, &cur_pos, &objp->orient.v.fvec, distance);
1011 for ( objp2 = GET_FIRST(&obj_used_list); objp2 != END_OF_LIST(&obj_used_list); objp2 = GET_NEXT(objp2) ) {
1012 if ((objp != objp2) && (objp2->type == OBJ_SHIP)) {
1013 if (Ship_info[Ships[objp2->instance].ship_info_index].flags & (SIF_BIG_SHIP | SIF_HUGE_SHIP)) {
1014 if (objp2 == dock_objp)
1017 if (cpls_aux(&goal_pos, objp2, objp))
1020 } else if (!(sip->flags & (SIF_BIG_SHIP | SIF_HUGE_SHIP)) && (objp2->type == OBJ_ASTEROID)) {
1021 if (vm_vec_dist_quick(&objp2->pos, &objp->pos) < (distance + objp2->radius)*2.5f) {
1026 d1 = 2.5f * distance + objp2->radius;
1027 count = (int) (d1/(objp2->radius + objp->radius)); // Scale up distance, else looks like there would be a collision.
1029 vm_vec_normalized_dir(&delvec, &goal_pos, &cur_pos);
1030 vm_vec_scale(&delvec, d1/count);
1032 for (; count>0; count--) {
1033 if (vm_vec_dist_quick(&pos, &objp2->pos) < objp->radius + objp2->radius)
1035 vm_vec_add2(&pos, &delvec);
1044 // function to iterate through all object collision pairs looking for weapons
1045 // which could be deleted since they are not going to hit anything. Passed into this
1046 // function is a 'time' parameter used as watermark for which weapons to check.
1048 #define CRW_NO_OBJECT -1
1049 #define CRW_NO_PAIR 0
1050 #define CRW_IN_PAIR 1
1051 #define CRW_CAN_DELETE 2
1053 #define CRW_MAX_TO_DELETE 4
1055 char crw_status[MAX_WEAPONS];
1057 void crw_check_weapon( int weapon_num, int collide_next_check )
1059 float next_check_time;
1062 wp = &Weapons[weapon_num];
1064 // if this weapons life left > time before next collision, then we cannot remove it
1065 crw_status[WEAPON_INDEX(wp)] = CRW_IN_PAIR;
1066 next_check_time = ((float)(timestamp_until(collide_next_check)) / 1000.0f);
1067 if ( wp->lifeleft < next_check_time )
1068 crw_status[WEAPON_INDEX(wp)] = CRW_CAN_DELETE;
1071 int collide_remove_weapons( )
1074 int i, num_deleted, oldest_index, j, loop_count;
1077 // setup remove_weapon array. assume we can remove it.
1078 for (i = 0; i < MAX_WEAPONS; i++ ) {
1079 if ( Weapons[i].objnum == -1 )
1080 crw_status[i] = CRW_NO_OBJECT;
1082 crw_status[i] = CRW_NO_PAIR;
1085 // first pass is to see if any of the weapons don't have collision pairs.
1087 opp = &pair_used_list;
1089 while( opp != NULL ) {
1090 // for each collide pair, if the two objects can still collide, then set the remove_weapon
1091 // parameter for the weapon to 0. need to check both parameters
1092 if ( opp->a->type == OBJ_WEAPON )
1093 crw_check_weapon( opp->a->instance, opp->next_check_time );
1095 if ( opp->b->type == OBJ_WEAPON )
1096 crw_check_weapon( opp->b->instance, opp->next_check_time );
1101 // for each weapon which could be removed, delete the object
1103 for ( i = 0; i < MAX_WEAPONS; i++ ) {
1104 if ( crw_status[i] == CRW_CAN_DELETE ) {
1105 Assert( Weapons[i].objnum != -1 );
1106 obj_delete( Weapons[i].objnum );
1114 // if we didn't remove any weapons, try to the N oldest weapons. first checking for pairs, then
1115 // checking for oldest weapons in general. We will go through the loop a max of 2 times. first time
1116 // through, we check oldest weapons with pairs, next time through, for oldest weapons.
1119 for ( j = 0; j < CRW_MAX_TO_DELETE; j++ ) {
1120 oldest_time = 1000.0f;
1122 for (i = 0; i < MAX_WEAPONS; i++ ) {
1123 if ( Weapons[i].objnum == -1 ) // shouldn't happen, but this is the safe thing to do.
1125 if ( ((loop_count || crw_status[i] == CRW_NO_PAIR)) && (Weapons[i].lifeleft < oldest_time) ) {
1126 oldest_time = Weapons[i].lifeleft;
1130 if ( oldest_index != -1 ) {
1131 obj_delete(Weapons[oldest_index].objnum);
1136 // if we deleted some weapons, then we can break
1141 } while ( loop_count < 2);
1147 void set_hit_struct_info(collision_info_struct *hit, mc_info *mc, int submodel_rot_hit)
1149 hit->edge_hit = mc->edge_hit;
1150 hit->hit_pos = mc->hit_point_world;
1151 hit->hit_time = mc->hit_dist;
1152 hit->submodel_num = mc->hit_submodel;
1154 hit->submodel_rot_hit = submodel_rot_hit;