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 1.1 2002/05/03 03:28:10 root
15 * 18 7/15/99 9:20a Andsager
16 * FS2_DEMO initial checkin
18 * 17 6/14/99 3:21p Andsager
19 * Allow collisions between ship and its debris. Fix up collision pairs
20 * when large ship is warping out.
22 * 16 5/08/99 8:25p Dave
23 * Upped object pairs. First run of nebula lightning.
25 * 15 4/23/99 12:01p Johnson
28 * 14 4/21/99 6:15p Dave
29 * Did some serious housecleaning in the beam code. Made it ready to go
30 * for anti-fighter "pulse" weapons. Fixed collision pair creation. Added
31 * a handy macro for recalculating collision pairs for a given object.
33 * 13 4/20/99 3:41p Andsager
34 * Modify objects_will_collide to use endpoints
36 * 12 3/10/99 6:50p Dave
37 * Changed the way we buffer packets for all clients. Optimized turret
38 * fired packets. Did some weapon firing optimizations.
40 * 11 3/05/99 3:32p Dan
41 * Make out of collision pars message npirntf with "collision"
43 * 10 1/21/99 2:06p Dave
44 * Final checkin for multiplayer testing.
46 * 9 1/21/99 10:44a Dave
47 * More beam weapon stuff. Put in warmdown time.
49 * 8 1/15/99 5:01p Dave
50 * Fix for object collision problem.
52 * 7 1/12/99 5:45p Dave
53 * Moved weapon pipeline in multiplayer to almost exclusively client side.
54 * Very good results. Bandwidth goes down, playability goes up for crappy
55 * connections. Fixed object update problem for ship subsystems.
57 * 6 1/12/99 12:53a Dave
58 * More work on beam weapons - made collision detection very efficient -
59 * collide against all object types properly - made 3 movement types
60 * smooth. Put in test code to check for possible non-darkening pixels on
63 * 5 11/19/98 11:08p Andsager
64 * Check in of physics and collision detection of rotating submodels
66 * 4 11/05/98 5:55p Dave
67 * Big pass at reducing #includes
69 * 3 10/26/98 9:42a Dave
70 * Early flak gun support.
72 * 2 10/07/98 10:53a Dave
75 * 1 10/07/98 10:50a Dave
77 * 38 7/29/98 3:24p Allender
78 * don't call collision code when either of the object pairs is NULL.
80 * 37 4/08/98 8:38a Mike
81 * Make ships avoid player when attacking or guarding a faraway object.
83 * 36 4/02/98 11:40a Lawrance
84 * check for #ifdef DEMO instead of #ifdef DEMO_RELEASE
86 * 35 4/01/98 1:48p Allender
87 * major changes to ship collision in multiplayer. Clients now do own
88 * ship/ship collisions (with their own ship only) Modifed the hull
89 * update packet to be sent quicker when object is target of player.
91 * 34 4/01/98 10:57a Mike
92 * Reduce array sizes to save memory.
94 * 33 3/31/98 5:18p John
95 * Removed demo/save/restore. Made NDEBUG defined compile. Removed a
96 * bunch of debug stuff out of player file. Made model code be able to
97 * unload models and malloc out only however many models are needed.
100 * 32 3/06/98 12:45a Lawrance
101 * Rmove a bogus assert in the object pair save/restore
103 * 31 3/05/98 3:12p Mike
104 * Fix bugs in asteroid collisions. Throw asteroids at Galataea (needs to
105 * be made general). Add skill level support for asteroid throwing.
107 * 30 3/05/98 12:12a Mike
108 * Make an asteroid in the way prevent player warpout.
110 * 29 2/27/98 4:48p John
111 * Made objects keep track of number of pairs they have associated with
112 * them. Then, I can early out of the obj_remove_all which was 2.5% of
113 * frametime at beginning of sm2-2 which then is 0% after this.
115 * 28 2/26/98 10:07p Hoffoss
116 * Rewrote state saving and restoring to fix bugs and simplify the code.
118 * 27 2/23/98 9:00a Andsager
119 * improved back face culling of object:laser pairs to check relative
120 * velocity dot laser forward < 0 vs. v_other dot v_laser < 0
122 * 26 2/19/98 4:34p Lawrance
123 * Allow weapon-asteroid collisions
125 * 25 2/19/98 10:52a Sandeep
126 * AL: Have asteroids collide with all ships
128 * 24 2/12/98 11:45a Andsager
129 * Try to cull debris:weapon collisions before they collisoin pair is
130 * created. Look at movement in lifetime and whether debris is behind
133 * 23 2/07/98 3:54p John
134 * Added FVI to show_game_resources
136 * 22 2/06/98 7:29p John
137 * Made only players ships and player ship weapons do collisions with
140 * 21 2/05/98 11:49p Andsager
141 * Don't check laser:ship collisions on same team for small ships if laser
144 * 20 2/05/98 9:21p John
145 * Some new Direct3D code. Added code to monitor a ton of stuff in the
148 * 19 2/05/98 12:51a Mike
149 * Early asteroid stuff.
151 * 18 2/03/98 9:40a Andsager
152 * Modify collision object pair creation code so that pairs between debris
153 * and weapons (other than player) are not created.
155 * 17 1/28/98 11:06a Andsager
156 * Remove some collision pairs. Add debug code for displaying collision
159 * 16 1/24/98 11:16a Andsager
162 * 15 1/24/98 11:09a Andsager
163 * Fixed bug that was removing collision pairs when weapon within the
166 * 14 1/23/98 5:07p Andsager
167 * Added tests for object pairs. (1) for weapons that do not turn, find
168 * the soonest hit time. (2) Check if soonest hit time if after end of
171 * 13 1/22/98 6:43p John
172 * Took out debug code.
174 * 12 1/22/98 6:42p John
175 * Move game_flush out of debug console into freespace. Made object
176 * pair code throw out some weapons that turn. Added stats for how many
177 * object pair are actually checked.
179 * 11 1/17/98 10:06p Lawrance
180 * For missiles, only collide if WIF_BOMB flag set.
182 * 10 1/14/98 5:21p Allender
183 * system to delete object when buffer is nearly full. System in place to
184 * delete weapons when nearly out of weapons slots
186 * 9 1/13/98 8:09p John
187 * Removed the old collision system that checked all pairs. Added code
188 * to disable collisions and particles.
190 * 8 1/13/98 3:11p Allender
191 * new code to remove old weapons when no more weapon slots available.
192 * Currently not called anywhere pending further testing
194 * 7 1/10/98 3:22p Allender
195 * temporary check in to get new code
197 * 6 1/10/98 1:14p John
198 * Added explanation to debug console commands
200 * 5 1/09/98 9:29a Mike
201 * Enable docked ships to warp out. Make damage done to a ship not
202 * proportional to its own mass.
204 * 4 1/08/98 12:12a Mike
205 * Make ships turn before warping out, if necessary, to avoid a collision.
206 * Warn player if his warpout will collide. Abort if in stage1.
208 * 3 12/21/97 4:33p John
209 * Made debug console functions a class that registers itself
210 * automatically, so you don't need to add the function to
211 * debugfunctions.cpp.
213 * 2 12/16/97 5:23p Allender
214 * don't deal with object collision paris on multiplayer clients
216 * 1 9/17/97 2:14p John
222 #include "objcollide.h"
223 #include "linklist.h"
224 #include "systemvars.h"
230 #define MAX_PAIRS 3000
232 #define MAX_PAIRS 8000 // Reduced from 10,000 to 6,000 by MK on 4/1/98.
233 // Most I saw was 3400 in sm1-06a, the asteriod mission. No other mission came close.
236 // the next 3 variables are used for pair statistics
237 // also in weapon.cpp there is Weapons_created.
238 int Pairs_created = 0;
240 int Num_pairs_checked = 0;
241 int pairs_not_created = 0;
243 int Num_pairs_hwm = 0;
245 obj_pair Obj_pairs[MAX_PAIRS];
247 obj_pair pair_used_list;
248 obj_pair pair_free_list;
250 void obj_reset_pairs()
254 // mprintf(( "Resetting object pairs...\n" ));
256 pair_used_list.a = pair_used_list.b = NULL;
257 pair_used_list.next = NULL;
258 pair_free_list.a = pair_free_list.b = NULL;
259 pair_free_list.next = &Obj_pairs[0];
262 for (i=0; i<MAX_PAIRS; i++ ) {
263 Obj_pairs[i].a = Obj_pairs[i].b = NULL;
264 Obj_pairs[i].next = &Obj_pairs[i+1];
266 Obj_pairs[MAX_PAIRS-1].next = NULL;
269 // returns true if we should reject object pair if one is child of other.
270 int reject_obj_pair_on_parent(object *A, object *B)
272 if (A->type == OBJ_SHIP) {
273 if (B->type == OBJ_DEBRIS) {
274 if (B->parent_sig == A->signature) {
280 if (B->type == OBJ_SHIP) {
281 if (A->type == OBJ_DEBRIS) {
282 if (A->parent_sig == B->signature) {
288 if (A->parent_sig == B->signature) {
292 if (B->parent_sig == A->signature) {
300 // Adds the pair to the pair list
301 void obj_add_pair( object *A, object *B, int check_time, int add_to_end )
304 int (*check_collision)( obj_pair *pair );
307 check_collision = NULL;
309 if ( A==B ) return; // Don't check collisions with yourself
311 if ( !(A->flags&OF_COLLIDES) ) return; // This object doesn't collide with anything
312 if ( !(B->flags&OF_COLLIDES) ) return; // This object doesn't collide with anything
314 // Make sure you're not checking a parent with it's kid or vicy-versy
315 // if ( A->parent_sig == B->signature && !(A->type == OBJ_SHIP && B->type == OBJ_DEBRIS) ) return;
316 // if ( B->parent_sig == A->signature && !(A->type == OBJ_DEBRIS && B->type == OBJ_SHIP) ) return;
317 if ( reject_obj_pair_on_parent(A,B) ) {
321 Assert( A->type < 127 );
322 Assert( B->type < 127 );
324 ctype = COLLISION_OF(A->type,B->type);
326 case COLLISION_OF(OBJ_WEAPON,OBJ_SHIP):
328 check_collision = collide_ship_weapon;
330 case COLLISION_OF(OBJ_SHIP, OBJ_WEAPON):
331 check_collision = collide_ship_weapon;
333 case COLLISION_OF(OBJ_DEBRIS, OBJ_WEAPON):
334 check_collision = collide_debris_weapon;
336 case COLLISION_OF(OBJ_WEAPON, OBJ_DEBRIS):
338 check_collision = collide_debris_weapon;
340 case COLLISION_OF(OBJ_DEBRIS, OBJ_SHIP):
341 check_collision = collide_debris_ship;
343 case COLLISION_OF(OBJ_SHIP, OBJ_DEBRIS):
344 check_collision = collide_debris_ship;
347 case COLLISION_OF(OBJ_ASTEROID, OBJ_WEAPON):
348 // Only check collision's with player weapons
349 // if ( Objects[B->parent].flags & OF_PLAYER_SHIP ) {
350 check_collision = collide_asteroid_weapon;
353 case COLLISION_OF(OBJ_WEAPON, OBJ_ASTEROID):
355 // Only check collision's with player weapons
356 // if ( Objects[A->parent].flags & OF_PLAYER_SHIP ) {
357 check_collision = collide_asteroid_weapon;
360 case COLLISION_OF(OBJ_ASTEROID, OBJ_SHIP):
361 // Only check collisions with player ships
362 // if ( B->flags & OF_PLAYER_SHIP ) {
363 check_collision = collide_asteroid_ship;
366 case COLLISION_OF(OBJ_SHIP, OBJ_ASTEROID):
367 // Only check collisions with player ships
368 // if ( A->flags & OF_PLAYER_SHIP ) {
369 check_collision = collide_asteroid_ship;
373 case COLLISION_OF(OBJ_SHIP,OBJ_SHIP):
374 check_collision = collide_ship_ship;
377 case COLLISION_OF(OBJ_BEAM, OBJ_SHIP):
378 if(beam_collide_early_out(A, B)){
381 check_collision = beam_collide_ship;
384 case COLLISION_OF(OBJ_BEAM, OBJ_ASTEROID):
385 if(beam_collide_early_out(A, B)){
388 check_collision = beam_collide_asteroid;
391 case COLLISION_OF(OBJ_BEAM, OBJ_DEBRIS):
392 if(beam_collide_early_out(A, B)){
395 check_collision = beam_collide_debris;
398 case COLLISION_OF(OBJ_BEAM, OBJ_WEAPON):
399 if(beam_collide_early_out(A, B)){
402 check_collision = beam_collide_missile;
405 case COLLISION_OF(OBJ_WEAPON, OBJ_WEAPON): {
406 weapon_info *awip, *bwip;
407 awip = &Weapon_info[Weapons[A->instance].weapon_info_index];
408 bwip = &Weapon_info[Weapons[B->instance].weapon_info_index];
410 if (awip->subtype != WP_LASER || bwip->subtype != WP_LASER) {
411 if (awip->subtype == WP_LASER) {
412 if ( bwip->wi_flags & WIF_BOMB ) {
413 check_collision = collide_weapon_weapon;
415 } else if (bwip->subtype == WP_LASER) {
416 if ( awip->wi_flags & WIF_BOMB ) {
417 check_collision = collide_weapon_weapon;
421 if ( (awip->wi_flags&WIF_BOMB) || (bwip->wi_flags&WIF_BOMB) ) {
422 check_collision = collide_weapon_weapon;
429 atype = Weapon_info[Weapons[A->instance].weapon_info_index].subtype;
430 btype = Weapon_info[Weapons[B->instance].weapon_info_index].subtype;
432 if ((atype == WP_LASER) && (btype == WP_MISSILE))
433 check_collision = collide_weapon_weapon;
434 else if ((atype == WP_MISSILE) && (btype == WP_LASER)) {
435 check_collision = collide_weapon_weapon;
437 } else if ((atype == WP_MISSILE) && (btype == WP_MISSILE))
438 check_collision = collide_weapon_weapon;
448 // Swap them if needed
455 // if there are any more obj_pair checks
456 // we should then add function int maybe_not_add_obj_pair()
457 // MWA -- 4/1/98 -- I'd do it, but I don't want to bust anything, so I'm doing my stuff here instead :-)
458 //if ( MULTIPLAYER_CLIENT && !(Netgame.debug_flags & NETD_FLAG_CLIENT_NODAMAGE)){
459 // multiplayer clients will only do ship/ship collisions, and their own ship to boot
460 // if ( check_collision != collide_ship_ship ){
464 // if ( (A != Player_obj) && (B != Player_obj) ){
469 // only check debris:weapon collisions for player
470 if (check_collision == collide_debris_weapon) {
472 if ( !(Weapon_info[Weapons[B->instance].weapon_info_index].wi_flags & WIF_TURNS) ) {
473 // check for dumbfire weapon
474 // check if debris is behind laser
476 if (Weapon_info[Weapons[B->instance].weapon_info_index].subtype == WP_LASER) {
477 vector velocity_rel_weapon;
478 vm_vec_sub(&velocity_rel_weapon, &B->phys_info.vel, &A->phys_info.vel);
479 vdot = -vm_vec_dot(&velocity_rel_weapon, &B->orient.fvec);
481 vdot = vm_vec_dot( &A->phys_info.vel, &B->phys_info.vel);
483 if ( vdot <= 0.0f ) {
484 // They're heading in opposite directions...
485 // check their positions
487 vm_vec_sub( &weapon2other, &A->pos, &B->pos );
488 float pdot = vm_vec_dot( &B->orient.fvec, &weapon2other );
489 if ( pdot <= -A->radius ) {
490 // The other object is behind the weapon by more than
491 // its radius, so it will never hit...
496 // check dist vs. dist moved during weapon lifetime
498 vm_vec_sub(&delta_v, &B->phys_info.vel, &A->phys_info.vel);
499 if (vm_vec_dist_squared(&A->pos, &B->pos) > (vm_vec_mag_squared(&delta_v)*Weapons[B->instance].lifeleft*Weapons[B->instance].lifeleft)) {
503 // for nonplayer ships, only create collision pair if close enough
504 if ( !(Objects[B->parent].flags & OF_PLAYER_SHIP) && (vm_vec_dist(&B->pos, &A->pos) < (4.0f*A->radius + 200.0f)) )
509 // don't check same team laser:ship collisions on small ships if not player
510 if (check_collision == collide_ship_weapon) {
512 if ( !(Objects[B->parent].flags & OF_PLAYER_SHIP)
513 && (Ships[Objects[B->parent].instance].team == Ships[A->instance].team)
514 && (Ship_info[Ships[A->instance].ship_info_index].flags & SIF_SMALL_SHIP)
515 && (Weapon_info[Weapons[B->instance].weapon_info_index].subtype == WP_LASER) ) {
521 if ( !check_collision ) return;
524 // At this point, we have determined that collisions between
525 // these two should be checked, so add the pair to the
526 // collision pair list.
528 if ( pair_free_list.next == NULL ) {
529 nprintf(( "collision", "Out of object pairs!! Not all collisions will work!\n" ));
533 // get a new obj_pair from the free list
534 obj_pair * new_pair = pair_free_list.next;
535 pair_free_list.next = new_pair->next;
538 obj_pair *last, *tmp;
540 last = tmp = pair_used_list.next;
541 while( tmp != NULL ) {
542 if ( tmp->next == NULL )
549 last = &pair_used_list;
551 last->next = new_pair;
552 Assert(new_pair != NULL);
553 new_pair->next = NULL;
556 new_pair->next = pair_used_list.next;
557 pair_used_list.next = new_pair;
561 /* if (Num_pairs > Num_pairs_hwm) {
562 Num_pairs_hwm = Num_pairs;
563 //nprintf(("AI", "Num_pairs high water mark = %i\n", Num_pairs_hwm));
572 new_pair->check_collision = check_collision;
574 if ( check_time == -1 ){
575 new_pair->next_check_time = timestamp(0); // 0 means instantly time out
577 new_pair->next_check_time = check_time;
583 MONITOR(NumPairsChecked);
585 void obj_check_all_collisions()
587 if ( !(Game_detail_flags & DETAIL_FLAG_COLLISION) ) return;
589 obj_pair *parent, *tmp;
591 float avg_time_to_next_check = 0.0f;
593 parent = &pair_used_list;
596 Num_pairs_checked = 0;
598 while( tmp != NULL ) {
601 if ( (tmp->a != NULL) && (tmp->b != NULL) && timestamp_elapsed(tmp->next_check_time) ) {
604 if ((*tmp->check_collision)(tmp)) {
605 // We never need to check this pair again.
606 #if 0 //def DONT_REMOVE_PAIRS
607 // Never check it again, but keep the pair around
608 // (useful for debugging)
609 tmp->next_check_time = timestamp(-1);
611 // Never check it again, so remove the pair
614 Assert( tmp->a->num_pairs > -1 );
616 Assert( tmp->b->num_pairs > -1 );
618 // Assert(Num_pairs >= 0);
619 parent->next = tmp->next;
620 tmp->a = tmp->b = NULL;
621 tmp->next = pair_free_list.next;
622 pair_free_list.next = tmp;
633 int add_time = timestamp_until( tmp->next_check_time );
635 avg_time_to_next_check += (float) add_time;
640 MONITOR_INC(NumPairs,Num_pairs);
641 MONITOR_INC(NumPairsChecked,Num_pairs_checked);
643 // #define PAIR_STATS
645 avg_time_to_next_check = avg_time_to_next_check / Num_pairs;
646 extern int Num_hull_pieces;
647 extern int Weapons_created;
648 // 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 ));
649 // 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) ));
650 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) ));
651 pairs_not_created = 0;
656 // What percent of the pairs did we check?
657 // FYI: (n*(n-1))/2 is the total number of checks required for comparing n objects.
659 // if ( org_pairs > 1 ) {
660 // Object_checked_percentage = (i2fl(n)*100.0f) / i2fl(org_pairs);
662 // Object_checked_percentage = 0.0f;
667 // See if two lines intersect by doing recursive subdivision.
668 // Bails out if larger distance traveled is less than sum of radii + 1.0f.
669 int collide_subdivide(vector *p0, vector *p1, float prad, vector *q0, vector *q1, float qrad)
671 float a_dist, b_dist, ab_dist;
673 a_dist = vm_vec_dist(p0, p1);
674 b_dist = vm_vec_dist(q0, q1);
676 ab_dist = vm_vec_dist(p1, q1);
678 // See if their spheres intersect
679 if (ab_dist < a_dist + b_dist + prad + qrad) {
680 if (ab_dist < prad + qrad)
682 else if (vm_vec_dist(p0, q0) < prad + qrad)
684 else if (max(a_dist, b_dist) < prad + qrad + 1.0f)
690 vm_vec_avg(&pa, p0, p1);
691 vm_vec_avg(&qa, q0, q1);
692 r1 = collide_subdivide(p0, &pa, prad, q0, &qa, qrad);
694 r2 = collide_subdivide(&pa, p1, prad, &qa, q1, qrad);
704 // Return true if object A is expected to collide with object B within time duration
705 // For purposes of this check, the first object moves from current location to predicted
706 // location. The second object is assumed to be where it will be at time duration, NOT
707 // where it currently is.
708 // radius_scale is used to control the precision of the check.
709 // If 0.0, then use polygon models to perform check, slow and accurate
710 // If !0.0, then use as a scale on the radius of the objects. 1.0 is Descent style
711 // collisions. Larger values can be used to be sloppy about the collisions which
712 // is useful if a moving object wants to prevent a collision.
713 int objects_will_collide(object *A, object *B, float duration, float radius_scale)
720 vm_vec_scale_add2(&A_future.pos, &A->phys_info.vel, duration);
722 if (radius_scale == 0.0f) {
723 return ship_check_collision_fast(B, &A_future, &hitpos );
725 float size_A, size_B, dist, r;
726 vector nearest_point;
728 size_A = A->radius * radius_scale;
729 size_B = B->radius * radius_scale;
731 // If A is moving, check along vector.
732 if (A->phys_info.speed != 0.0f) {
733 r = find_nearest_point_on_line(&nearest_point, &A->pos, &A_future.pos, &B->pos);
735 nearest_point = A->pos;
737 nearest_point = A_future.pos;
739 dist = vm_vec_dist_quick(&B->pos, &nearest_point);
740 return (dist < size_A + size_B);
742 return vm_vec_dist_quick(&B->pos, &A->pos) < size_A + size_B;
747 // Return true if the vector from *start_pos to *end_pos is within objp->radius*radius_scale of *objp
748 int vector_object_collision(vector *start_pos, vector *end_pos, object *objp, float radius_scale)
751 vector nearest_point;
753 r = find_nearest_point_on_line(&nearest_point, start_pos, end_pos, &objp->pos);
754 if ((r >= 0.0f) && (r <= 1.0f)) {
755 dist = vm_vec_dist_quick(&objp->pos, &nearest_point);
757 return (dist < objp->radius * radius_scale);
762 // Returns TRUE if the weapon will never hit the other object.
763 // If it can it predicts how long until these two objects need
764 // to be checked and fills the time in in current_pair.
765 int weapon_will_never_hit( object *weapon, object *other, obj_pair * current_pair )
768 Assert( weapon->type == OBJ_WEAPON );
770 // mprintf(( "Frame: %d, Weapon=%d, Other=%d, pair=$%08x\n", G3_frame_count, OBJ_INDEX(weapon), OBJ_INDEX(other), current_pair ));
773 // Do some checks for weapons that don't turn
774 if ( !(Weapon_info[Weapons[weapon->instance].weapon_info_index].wi_flags & WIF_TURNS) ) {
776 // This first check is to see if a weapon is behind an object, and they
777 // are heading in opposite directions. If so, we don't need to ever check
778 // them again. This is only valid for weapons that don't turn.
781 if (Weapon_info[Weapons[weapon->instance].weapon_info_index].subtype == WP_LASER) {
782 vector velocity_rel_weapon;
783 vm_vec_sub(&velocity_rel_weapon, &weapon->phys_info.vel, &other->phys_info.vel);
784 vdot = -vm_vec_dot(&velocity_rel_weapon, &weapon->orient.fvec);
786 vdot = vm_vec_dot( &other->phys_info.vel, &weapon->phys_info.vel);
788 if ( vdot <= 0.0f ) {
789 // They're heading in opposite directions...
790 // check their positions
792 vm_vec_sub( &weapon2other, &other->pos, &weapon->pos );
793 float pdot = vm_vec_dot( &weapon->orient.fvec, &weapon2other );
794 if ( pdot <= -other->radius ) {
795 // The other object is behind the weapon by more than
796 // its radius, so it will never hit...
801 // FUTURE ENHANCEMENT IDEAS
803 // Given a laser does it hit a slow or not moving object
804 // in its life or the next n seconds? We'd actually need to check the
810 // This check doesn't care about orient, only looks at the maximum speed
811 // of the two objects, so it knows that in the next n seconds, they can't
812 // go further than some distance, so don't bother checking collisions for
813 // that time. This is very rough, but is so general that it works for
814 // everything and immidiately gets rid of a lot of cases.
816 if ( current_pair ) {
817 // Find the time it will take before these get within each others distances.
818 // tmp->next_check_time = timestamp(500);
819 //vector max_vel; //maximum foward velocity in x,y,z
821 float max_vel_weapon, max_vel_other;
822 max_vel_weapon = weapon->phys_info.max_vel.z;
823 max_vel_other = other->phys_info.max_vel.z;
824 if (max_vel_other < 10.0f) {
825 if ( vm_vec_mag_squared( &other->phys_info.vel ) > 100 ) {
826 // bump up velocity from collision
827 max_vel_other = vm_vec_mag( &other->phys_info.vel ) + 10.0f;
829 max_vel_other = 10.0f; // object may move from collision
833 // check weapon that does not turn against sphere expanding at ship maxvel
834 // compare (weeapon) ray with expanding sphere (ship) to find earliest possible collision time
835 // look for two time solutions to Xw = Xs, where Xw = Xw0 + Vwt*t Xs = Xs + Vs*(t+dt), where Vs*dt = radius of ship
836 // Since direction of Vs is unknown, solve for (Vs*t) and find norm of both sides
837 if ( !(Weapon_info[Weapons[weapon->instance].weapon_info_index].wi_flags & WIF_TURNS) ) {
838 vector delta_x, laser_vel;
839 float a,b,c, delta_x_dot_vl, delta_t;
840 float root1, root2, root, earliest_time;
842 vm_vec_sub( &delta_x, &weapon->pos, &other->pos );
843 vm_vec_copy_scale( &laser_vel, &weapon->orient.fvec, max_vel_weapon );
844 delta_t = (other->radius + 10.0f) / max_vel_other; // time to get from center to radius of other obj
845 delta_x_dot_vl = vm_vec_dotprod( &delta_x, &laser_vel );
847 a = max_vel_weapon*max_vel_weapon - max_vel_other*max_vel_other;
848 b = 2.0f * (delta_x_dot_vl - max_vel_other*max_vel_other*delta_t);
849 c = vm_vec_mag_squared( &delta_x ) - max_vel_other*max_vel_other*delta_t*delta_t;
851 float discriminant = b*b - 4.0f*a*c;
852 if ( discriminant < 0) {
856 root = fl_sqrt( discriminant );
857 root1 = (-b + root) / (2.0f * a) * 1000.0f; // get time in ms
858 root2 = (-b - root) / (2.0f * a) * 1000.0f; // get time in ms
861 // find earliest positive time
862 if ( root1 > root2 ) {
869 earliest_time = root1;
870 } else if (root2 > 0) {
871 // root1 < 0 and root2 > 0, so we're inside sphere and next check should be next frame
872 current_pair->next_check_time = timestamp(0); // check next time
875 // both times negative, so never collides
881 // check if possible collision occurs after weapon expires
882 if ( earliest_time > 1000*Weapons[weapon->instance].lifeleft )
885 // Allow one worst case frametime to elapse (~5 fps)
886 earliest_time -= 200.0f;
888 if (earliest_time > 100) {
889 current_pair->next_check_time = timestamp( fl2i(earliest_time) );
892 current_pair->next_check_time = timestamp(0); // check next time
898 float dist, max_vel, time;
900 max_vel = max_vel_weapon + max_vel_other;
902 // suggest that fudge factor for other radius be changed to other_radius + const (~10)
903 dist = vm_vec_dist( &other->pos, &weapon->pos ) - (other->radius + 10.0f);
905 time = (dist*1000.0f) / max_vel;
906 int time_ms = fl2i(time);
908 // check if possible collision occurs after weapon expires
909 if ( time_ms > 1000*Weapons[weapon->instance].lifeleft )
912 time_ms -= 200; // Allow at least one worst case frametime to elapse (~5 fps)
914 if ( time_ms > 100 ) { // If it takes longer than 1/10th of a second, then delay it
915 current_pair->next_check_time = timestamp(time_ms);
916 //mprintf(( "Delaying %d ms\n", time_ms ));
920 current_pair->next_check_time = timestamp(0); // check next time
928 // Return true if vector from *curpos to *goalpos intersects with object *goalobjp
929 // Else, return false.
930 // radius is radius of object moving from curpos to goalpos.
931 int pp_collide(vector *curpos, vector *goalpos, object *goalobjp, float radius)
935 Assert(goalobjp->type == OBJ_SHIP);
937 ship_model_start(goalobjp);
939 mc.model_num = Ships[goalobjp->instance].modelnum; // Fill in the model to check
940 mc.orient = &goalobjp->orient; // The object's orient
941 mc.pos = &goalobjp->pos; // The object's position
942 mc.p0 = curpos; // Point 1 of ray to check
943 mc.p1 = goalpos; // Point 2 of ray to check
944 mc.flags = MC_CHECK_MODEL | MC_CHECK_SPHERELINE;
949 ship_model_stop(goalobjp);
954 // Setup and call pp_collide for collide_predict_large_ship
955 // Returns true if objp will collide with objp2 before it reaches goal_pos.
956 int cpls_aux(vector *goal_pos, object *objp2, object *objp)
960 radius = objp->radius;
961 if (1.5f * radius < 70.0f)
966 if (pp_collide(&objp->pos, goal_pos, objp2, radius))
972 // Return true if objp will collide with some large object.
973 // Don't check for an object this ship is docked to.
974 int collide_predict_large_ship(object *objp, float distance)
977 vector cur_pos, goal_pos;
981 sip = &Ship_info[Ships[objp->instance].ship_info_index];
984 if (objp->type == OBJ_SHIP) {
985 ai_info *aip = &Ai_info[Ships[objp->instance].ai_index];
986 if (aip->dock_objnum != -1)
987 dock_objp = &Objects[aip->dock_objnum];
992 vm_vec_scale_add(&goal_pos, &cur_pos, &objp->orient.fvec, distance);
994 for ( objp2 = GET_FIRST(&obj_used_list); objp2 != END_OF_LIST(&obj_used_list); objp2 = GET_NEXT(objp2) ) {
995 if ((objp != objp2) && (objp2->type == OBJ_SHIP)) {
996 if (Ship_info[Ships[objp2->instance].ship_info_index].flags & (SIF_BIG_SHIP | SIF_HUGE_SHIP)) {
997 if (objp2 == dock_objp)
1000 if (cpls_aux(&goal_pos, objp2, objp))
1003 } else if (!(sip->flags & (SIF_BIG_SHIP | SIF_HUGE_SHIP)) && (objp2->type == OBJ_ASTEROID)) {
1004 if (vm_vec_dist_quick(&objp2->pos, &objp->pos) < (distance + objp2->radius)*2.5f) {
1009 d1 = 2.5f * distance + objp2->radius;
1010 count = (int) (d1/(objp2->radius + objp->radius)); // Scale up distance, else looks like there would be a collision.
1012 vm_vec_normalized_dir(&delvec, &goal_pos, &cur_pos);
1013 vm_vec_scale(&delvec, d1/count);
1015 for (; count>0; count--) {
1016 if (vm_vec_dist_quick(&pos, &objp2->pos) < objp->radius + objp2->radius)
1018 vm_vec_add2(&pos, &delvec);
1027 // function to iterate through all object collision pairs looking for weapons
1028 // which could be deleted since they are not going to hit anything. Passed into this
1029 // function is a 'time' parameter used as watermark for which weapons to check.
1031 #define CRW_NO_OBJECT -1
1032 #define CRW_NO_PAIR 0
1033 #define CRW_IN_PAIR 1
1034 #define CRW_CAN_DELETE 2
1036 #define CRW_MAX_TO_DELETE 4
1038 char crw_status[MAX_WEAPONS];
1040 void crw_check_weapon( int weapon_num, int collide_next_check )
1042 float next_check_time;
1045 wp = &Weapons[weapon_num];
1047 // if this weapons life left > time before next collision, then we cannot remove it
1048 crw_status[WEAPON_INDEX(wp)] = CRW_IN_PAIR;
1049 next_check_time = ((float)(timestamp_until(collide_next_check)) / 1000.0f);
1050 if ( wp->lifeleft < next_check_time )
1051 crw_status[WEAPON_INDEX(wp)] = CRW_CAN_DELETE;
1054 int collide_remove_weapons( )
1057 int i, num_deleted, oldest_index, j, loop_count;
1060 // setup remove_weapon array. assume we can remove it.
1061 for (i = 0; i < MAX_WEAPONS; i++ ) {
1062 if ( Weapons[i].objnum == -1 )
1063 crw_status[i] = CRW_NO_OBJECT;
1065 crw_status[i] = CRW_NO_PAIR;
1068 // first pass is to see if any of the weapons don't have collision pairs.
1070 opp = &pair_used_list;
1072 while( opp != NULL ) {
1073 // for each collide pair, if the two objects can still collide, then set the remove_weapon
1074 // parameter for the weapon to 0. need to check both parameters
1075 if ( opp->a->type == OBJ_WEAPON )
1076 crw_check_weapon( opp->a->instance, opp->next_check_time );
1078 if ( opp->b->type == OBJ_WEAPON )
1079 crw_check_weapon( opp->b->instance, opp->next_check_time );
1084 // for each weapon which could be removed, delete the object
1086 for ( i = 0; i < MAX_WEAPONS; i++ ) {
1087 if ( crw_status[i] == CRW_CAN_DELETE ) {
1088 Assert( Weapons[i].objnum != -1 );
1089 obj_delete( Weapons[i].objnum );
1097 // if we didn't remove any weapons, try to the N oldest weapons. first checking for pairs, then
1098 // checking for oldest weapons in general. We will go through the loop a max of 2 times. first time
1099 // through, we check oldest weapons with pairs, next time through, for oldest weapons.
1102 for ( j = 0; j < CRW_MAX_TO_DELETE; j++ ) {
1103 oldest_time = 1000.0f;
1105 for (i = 0; i < MAX_WEAPONS; i++ ) {
1106 if ( Weapons[i].objnum == -1 ) // shouldn't happen, but this is the safe thing to do.
1108 if ( ((loop_count || crw_status[i] == CRW_NO_PAIR)) && (Weapons[i].lifeleft < oldest_time) ) {
1109 oldest_time = Weapons[i].lifeleft;
1113 if ( oldest_index != -1 ) {
1114 obj_delete(Weapons[oldest_index].objnum);
1119 // if we deleted some weapons, then we can break
1124 } while ( loop_count < 2);
1130 void set_hit_struct_info(collision_info_struct *hit, mc_info *mc, int submodel_rot_hit)
1132 hit->edge_hit = mc->edge_hit;
1133 hit->hit_pos = mc->hit_point_world;
1134 hit->hit_time = mc->hit_dist;
1135 hit->submodel_num = mc->hit_submodel;
1137 hit->submodel_rot_hit = submodel_rot_hit;