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 1.3 2002/06/09 04:41:24 relnev
20 * added copyright header
22 * Revision 1.2 2002/05/07 03:16:48 theoddone33
23 * The Great Newline Fix
25 * Revision 1.1.1.1 2002/05/03 03:28:10 root
29 * 18 7/15/99 9:20a Andsager
30 * FS2_DEMO initial checkin
32 * 17 6/14/99 3:21p Andsager
33 * Allow collisions between ship and its debris. Fix up collision pairs
34 * when large ship is warping out.
36 * 16 5/08/99 8:25p Dave
37 * Upped object pairs. First run of nebula lightning.
39 * 15 4/23/99 12:01p Johnson
42 * 14 4/21/99 6:15p Dave
43 * Did some serious housecleaning in the beam code. Made it ready to go
44 * for anti-fighter "pulse" weapons. Fixed collision pair creation. Added
45 * a handy macro for recalculating collision pairs for a given object.
47 * 13 4/20/99 3:41p Andsager
48 * Modify objects_will_collide to use endpoints
50 * 12 3/10/99 6:50p Dave
51 * Changed the way we buffer packets for all clients. Optimized turret
52 * fired packets. Did some weapon firing optimizations.
54 * 11 3/05/99 3:32p Dan
55 * Make out of collision pars message npirntf with "collision"
57 * 10 1/21/99 2:06p Dave
58 * Final checkin for multiplayer testing.
60 * 9 1/21/99 10:44a Dave
61 * More beam weapon stuff. Put in warmdown time.
63 * 8 1/15/99 5:01p Dave
64 * Fix for object collision problem.
66 * 7 1/12/99 5:45p Dave
67 * Moved weapon pipeline in multiplayer to almost exclusively client side.
68 * Very good results. Bandwidth goes down, playability goes up for crappy
69 * connections. Fixed object update problem for ship subsystems.
71 * 6 1/12/99 12:53a Dave
72 * More work on beam weapons - made collision detection very efficient -
73 * collide against all object types properly - made 3 movement types
74 * smooth. Put in test code to check for possible non-darkening pixels on
77 * 5 11/19/98 11:08p Andsager
78 * Check in of physics and collision detection of rotating submodels
80 * 4 11/05/98 5:55p Dave
81 * Big pass at reducing #includes
83 * 3 10/26/98 9:42a Dave
84 * Early flak gun support.
86 * 2 10/07/98 10:53a Dave
89 * 1 10/07/98 10:50a Dave
91 * 38 7/29/98 3:24p Allender
92 * don't call collision code when either of the object pairs is NULL.
94 * 37 4/08/98 8:38a Mike
95 * Make ships avoid player when attacking or guarding a faraway object.
97 * 36 4/02/98 11:40a Lawrance
98 * check for #ifdef DEMO instead of #ifdef DEMO_RELEASE
100 * 35 4/01/98 1:48p Allender
101 * major changes to ship collision in multiplayer. Clients now do own
102 * ship/ship collisions (with their own ship only) Modifed the hull
103 * update packet to be sent quicker when object is target of player.
105 * 34 4/01/98 10:57a Mike
106 * Reduce array sizes to save memory.
108 * 33 3/31/98 5:18p John
109 * Removed demo/save/restore. Made NDEBUG defined compile. Removed a
110 * bunch of debug stuff out of player file. Made model code be able to
111 * unload models and malloc out only however many models are needed.
114 * 32 3/06/98 12:45a Lawrance
115 * Rmove a bogus assert in the object pair save/restore
117 * 31 3/05/98 3:12p Mike
118 * Fix bugs in asteroid collisions. Throw asteroids at Galataea (needs to
119 * be made general). Add skill level support for asteroid throwing.
121 * 30 3/05/98 12:12a Mike
122 * Make an asteroid in the way prevent player warpout.
124 * 29 2/27/98 4:48p John
125 * Made objects keep track of number of pairs they have associated with
126 * them. Then, I can early out of the obj_remove_all which was 2.5% of
127 * frametime at beginning of sm2-2 which then is 0% after this.
129 * 28 2/26/98 10:07p Hoffoss
130 * Rewrote state saving and restoring to fix bugs and simplify the code.
132 * 27 2/23/98 9:00a Andsager
133 * improved back face culling of object:laser pairs to check relative
134 * velocity dot laser forward < 0 vs. v_other dot v_laser < 0
136 * 26 2/19/98 4:34p Lawrance
137 * Allow weapon-asteroid collisions
139 * 25 2/19/98 10:52a Sandeep
140 * AL: Have asteroids collide with all ships
142 * 24 2/12/98 11:45a Andsager
143 * Try to cull debris:weapon collisions before they collisoin pair is
144 * created. Look at movement in lifetime and whether debris is behind
147 * 23 2/07/98 3:54p John
148 * Added FVI to show_game_resources
150 * 22 2/06/98 7:29p John
151 * Made only players ships and player ship weapons do collisions with
154 * 21 2/05/98 11:49p Andsager
155 * Don't check laser:ship collisions on same team for small ships if laser
158 * 20 2/05/98 9:21p John
159 * Some new Direct3D code. Added code to monitor a ton of stuff in the
162 * 19 2/05/98 12:51a Mike
163 * Early asteroid stuff.
165 * 18 2/03/98 9:40a Andsager
166 * Modify collision object pair creation code so that pairs between debris
167 * and weapons (other than player) are not created.
169 * 17 1/28/98 11:06a Andsager
170 * Remove some collision pairs. Add debug code for displaying collision
173 * 16 1/24/98 11:16a Andsager
176 * 15 1/24/98 11:09a Andsager
177 * Fixed bug that was removing collision pairs when weapon within the
180 * 14 1/23/98 5:07p Andsager
181 * Added tests for object pairs. (1) for weapons that do not turn, find
182 * the soonest hit time. (2) Check if soonest hit time if after end of
185 * 13 1/22/98 6:43p John
186 * Took out debug code.
188 * 12 1/22/98 6:42p John
189 * Move game_flush out of debug console into freespace. Made object
190 * pair code throw out some weapons that turn. Added stats for how many
191 * object pair are actually checked.
193 * 11 1/17/98 10:06p Lawrance
194 * For missiles, only collide if WIF_BOMB flag set.
196 * 10 1/14/98 5:21p Allender
197 * system to delete object when buffer is nearly full. System in place to
198 * delete weapons when nearly out of weapons slots
200 * 9 1/13/98 8:09p John
201 * Removed the old collision system that checked all pairs. Added code
202 * to disable collisions and particles.
204 * 8 1/13/98 3:11p Allender
205 * new code to remove old weapons when no more weapon slots available.
206 * Currently not called anywhere pending further testing
208 * 7 1/10/98 3:22p Allender
209 * temporary check in to get new code
211 * 6 1/10/98 1:14p John
212 * Added explanation to debug console commands
214 * 5 1/09/98 9:29a Mike
215 * Enable docked ships to warp out. Make damage done to a ship not
216 * proportional to its own mass.
218 * 4 1/08/98 12:12a Mike
219 * Make ships turn before warping out, if necessary, to avoid a collision.
220 * Warn player if his warpout will collide. Abort if in stage1.
222 * 3 12/21/97 4:33p John
223 * Made debug console functions a class that registers itself
224 * automatically, so you don't need to add the function to
225 * debugfunctions.cpp.
227 * 2 12/16/97 5:23p Allender
228 * don't deal with object collision paris on multiplayer clients
230 * 1 9/17/97 2:14p John
236 #include "objcollide.h"
237 #include "linklist.h"
238 #include "systemvars.h"
244 #define MAX_PAIRS 3000
246 #define MAX_PAIRS 8000 // Reduced from 10,000 to 6,000 by MK on 4/1/98.
247 // Most I saw was 3400 in sm1-06a, the asteriod mission. No other mission came close.
250 // the next 3 variables are used for pair statistics
251 // also in weapon.cpp there is Weapons_created.
252 int Pairs_created = 0;
254 int Num_pairs_checked = 0;
255 int pairs_not_created = 0;
257 int Num_pairs_hwm = 0;
259 obj_pair Obj_pairs[MAX_PAIRS];
261 obj_pair pair_used_list;
262 obj_pair pair_free_list;
264 void obj_reset_pairs()
268 // mprintf(( "Resetting object pairs...\n" ));
270 pair_used_list.a = pair_used_list.b = NULL;
271 pair_used_list.next = NULL;
272 pair_free_list.a = pair_free_list.b = NULL;
273 pair_free_list.next = &Obj_pairs[0];
276 for (i=0; i<MAX_PAIRS; i++ ) {
277 Obj_pairs[i].a = Obj_pairs[i].b = NULL;
278 Obj_pairs[i].next = &Obj_pairs[i+1];
280 Obj_pairs[MAX_PAIRS-1].next = NULL;
283 // returns true if we should reject object pair if one is child of other.
284 int reject_obj_pair_on_parent(object *A, object *B)
286 if (A->type == OBJ_SHIP) {
287 if (B->type == OBJ_DEBRIS) {
288 if (B->parent_sig == A->signature) {
294 if (B->type == OBJ_SHIP) {
295 if (A->type == OBJ_DEBRIS) {
296 if (A->parent_sig == B->signature) {
302 if (A->parent_sig == B->signature) {
306 if (B->parent_sig == A->signature) {
314 // Adds the pair to the pair list
315 void obj_add_pair( object *A, object *B, int check_time, int add_to_end )
318 int (*check_collision)( obj_pair *pair );
321 check_collision = NULL;
323 if ( A==B ) return; // Don't check collisions with yourself
325 if ( !(A->flags&OF_COLLIDES) ) return; // This object doesn't collide with anything
326 if ( !(B->flags&OF_COLLIDES) ) return; // This object doesn't collide with anything
328 // Make sure you're not checking a parent with it's kid or vicy-versy
329 // if ( A->parent_sig == B->signature && !(A->type == OBJ_SHIP && B->type == OBJ_DEBRIS) ) return;
330 // if ( B->parent_sig == A->signature && !(A->type == OBJ_DEBRIS && B->type == OBJ_SHIP) ) return;
331 if ( reject_obj_pair_on_parent(A,B) ) {
335 Assert( A->type < 127 );
336 Assert( B->type < 127 );
338 ctype = COLLISION_OF(A->type,B->type);
340 case COLLISION_OF(OBJ_WEAPON,OBJ_SHIP):
342 check_collision = collide_ship_weapon;
344 case COLLISION_OF(OBJ_SHIP, OBJ_WEAPON):
345 check_collision = collide_ship_weapon;
347 case COLLISION_OF(OBJ_DEBRIS, OBJ_WEAPON):
348 check_collision = collide_debris_weapon;
350 case COLLISION_OF(OBJ_WEAPON, OBJ_DEBRIS):
352 check_collision = collide_debris_weapon;
354 case COLLISION_OF(OBJ_DEBRIS, OBJ_SHIP):
355 check_collision = collide_debris_ship;
357 case COLLISION_OF(OBJ_SHIP, OBJ_DEBRIS):
358 check_collision = collide_debris_ship;
361 case COLLISION_OF(OBJ_ASTEROID, OBJ_WEAPON):
362 // Only check collision's with player weapons
363 // if ( Objects[B->parent].flags & OF_PLAYER_SHIP ) {
364 check_collision = collide_asteroid_weapon;
367 case COLLISION_OF(OBJ_WEAPON, OBJ_ASTEROID):
369 // Only check collision's with player weapons
370 // if ( Objects[A->parent].flags & OF_PLAYER_SHIP ) {
371 check_collision = collide_asteroid_weapon;
374 case COLLISION_OF(OBJ_ASTEROID, OBJ_SHIP):
375 // Only check collisions with player ships
376 // if ( B->flags & OF_PLAYER_SHIP ) {
377 check_collision = collide_asteroid_ship;
380 case COLLISION_OF(OBJ_SHIP, OBJ_ASTEROID):
381 // Only check collisions with player ships
382 // if ( A->flags & OF_PLAYER_SHIP ) {
383 check_collision = collide_asteroid_ship;
387 case COLLISION_OF(OBJ_SHIP,OBJ_SHIP):
388 check_collision = collide_ship_ship;
391 case COLLISION_OF(OBJ_BEAM, OBJ_SHIP):
392 if(beam_collide_early_out(A, B)){
395 check_collision = beam_collide_ship;
398 case COLLISION_OF(OBJ_BEAM, OBJ_ASTEROID):
399 if(beam_collide_early_out(A, B)){
402 check_collision = beam_collide_asteroid;
405 case COLLISION_OF(OBJ_BEAM, OBJ_DEBRIS):
406 if(beam_collide_early_out(A, B)){
409 check_collision = beam_collide_debris;
412 case COLLISION_OF(OBJ_BEAM, OBJ_WEAPON):
413 if(beam_collide_early_out(A, B)){
416 check_collision = beam_collide_missile;
419 case COLLISION_OF(OBJ_WEAPON, OBJ_WEAPON): {
420 weapon_info *awip, *bwip;
421 awip = &Weapon_info[Weapons[A->instance].weapon_info_index];
422 bwip = &Weapon_info[Weapons[B->instance].weapon_info_index];
424 if (awip->subtype != WP_LASER || bwip->subtype != WP_LASER) {
425 if (awip->subtype == WP_LASER) {
426 if ( bwip->wi_flags & WIF_BOMB ) {
427 check_collision = collide_weapon_weapon;
429 } else if (bwip->subtype == WP_LASER) {
430 if ( awip->wi_flags & WIF_BOMB ) {
431 check_collision = collide_weapon_weapon;
435 if ( (awip->wi_flags&WIF_BOMB) || (bwip->wi_flags&WIF_BOMB) ) {
436 check_collision = collide_weapon_weapon;
443 atype = Weapon_info[Weapons[A->instance].weapon_info_index].subtype;
444 btype = Weapon_info[Weapons[B->instance].weapon_info_index].subtype;
446 if ((atype == WP_LASER) && (btype == WP_MISSILE))
447 check_collision = collide_weapon_weapon;
448 else if ((atype == WP_MISSILE) && (btype == WP_LASER)) {
449 check_collision = collide_weapon_weapon;
451 } else if ((atype == WP_MISSILE) && (btype == WP_MISSILE))
452 check_collision = collide_weapon_weapon;
462 // Swap them if needed
469 // if there are any more obj_pair checks
470 // we should then add function int maybe_not_add_obj_pair()
471 // MWA -- 4/1/98 -- I'd do it, but I don't want to bust anything, so I'm doing my stuff here instead :-)
472 //if ( MULTIPLAYER_CLIENT && !(Netgame.debug_flags & NETD_FLAG_CLIENT_NODAMAGE)){
473 // multiplayer clients will only do ship/ship collisions, and their own ship to boot
474 // if ( check_collision != collide_ship_ship ){
478 // if ( (A != Player_obj) && (B != Player_obj) ){
483 // only check debris:weapon collisions for player
484 if (check_collision == collide_debris_weapon) {
486 if ( !(Weapon_info[Weapons[B->instance].weapon_info_index].wi_flags & WIF_TURNS) ) {
487 // check for dumbfire weapon
488 // check if debris is behind laser
490 if (Weapon_info[Weapons[B->instance].weapon_info_index].subtype == WP_LASER) {
491 vector velocity_rel_weapon;
492 vm_vec_sub(&velocity_rel_weapon, &B->phys_info.vel, &A->phys_info.vel);
493 vdot = -vm_vec_dot(&velocity_rel_weapon, &B->orient.fvec);
495 vdot = vm_vec_dot( &A->phys_info.vel, &B->phys_info.vel);
497 if ( vdot <= 0.0f ) {
498 // They're heading in opposite directions...
499 // check their positions
501 vm_vec_sub( &weapon2other, &A->pos, &B->pos );
502 float pdot = vm_vec_dot( &B->orient.fvec, &weapon2other );
503 if ( pdot <= -A->radius ) {
504 // The other object is behind the weapon by more than
505 // its radius, so it will never hit...
510 // check dist vs. dist moved during weapon lifetime
512 vm_vec_sub(&delta_v, &B->phys_info.vel, &A->phys_info.vel);
513 if (vm_vec_dist_squared(&A->pos, &B->pos) > (vm_vec_mag_squared(&delta_v)*Weapons[B->instance].lifeleft*Weapons[B->instance].lifeleft)) {
517 // for nonplayer ships, only create collision pair if close enough
518 if ( !(Objects[B->parent].flags & OF_PLAYER_SHIP) && (vm_vec_dist(&B->pos, &A->pos) < (4.0f*A->radius + 200.0f)) )
523 // don't check same team laser:ship collisions on small ships if not player
524 if (check_collision == collide_ship_weapon) {
526 if ( !(Objects[B->parent].flags & OF_PLAYER_SHIP)
527 && (Ships[Objects[B->parent].instance].team == Ships[A->instance].team)
528 && (Ship_info[Ships[A->instance].ship_info_index].flags & SIF_SMALL_SHIP)
529 && (Weapon_info[Weapons[B->instance].weapon_info_index].subtype == WP_LASER) ) {
535 if ( !check_collision ) return;
538 // At this point, we have determined that collisions between
539 // these two should be checked, so add the pair to the
540 // collision pair list.
542 if ( pair_free_list.next == NULL ) {
543 nprintf(( "collision", "Out of object pairs!! Not all collisions will work!\n" ));
547 // get a new obj_pair from the free list
548 obj_pair * new_pair = pair_free_list.next;
549 pair_free_list.next = new_pair->next;
552 obj_pair *last, *tmp;
554 last = tmp = pair_used_list.next;
555 while( tmp != NULL ) {
556 if ( tmp->next == NULL )
563 last = &pair_used_list;
565 last->next = new_pair;
566 Assert(new_pair != NULL);
567 new_pair->next = NULL;
570 new_pair->next = pair_used_list.next;
571 pair_used_list.next = new_pair;
575 /* if (Num_pairs > Num_pairs_hwm) {
576 Num_pairs_hwm = Num_pairs;
577 //nprintf(("AI", "Num_pairs high water mark = %i\n", Num_pairs_hwm));
586 new_pair->check_collision = check_collision;
588 if ( check_time == -1 ){
589 new_pair->next_check_time = timestamp(0); // 0 means instantly time out
591 new_pair->next_check_time = check_time;
597 MONITOR(NumPairsChecked);
599 void obj_check_all_collisions()
601 if ( !(Game_detail_flags & DETAIL_FLAG_COLLISION) ) return;
603 obj_pair *parent, *tmp;
605 float avg_time_to_next_check = 0.0f;
607 parent = &pair_used_list;
610 Num_pairs_checked = 0;
612 while( tmp != NULL ) {
615 if ( (tmp->a != NULL) && (tmp->b != NULL) && timestamp_elapsed(tmp->next_check_time) ) {
618 if ((*tmp->check_collision)(tmp)) {
619 // We never need to check this pair again.
620 #if 0 //def DONT_REMOVE_PAIRS
621 // Never check it again, but keep the pair around
622 // (useful for debugging)
623 tmp->next_check_time = timestamp(-1);
625 // Never check it again, so remove the pair
628 Assert( tmp->a->num_pairs > -1 );
630 Assert( tmp->b->num_pairs > -1 );
632 // Assert(Num_pairs >= 0);
633 parent->next = tmp->next;
634 tmp->a = tmp->b = NULL;
635 tmp->next = pair_free_list.next;
636 pair_free_list.next = tmp;
647 int add_time = timestamp_until( tmp->next_check_time );
649 avg_time_to_next_check += (float) add_time;
654 MONITOR_INC(NumPairs,Num_pairs);
655 MONITOR_INC(NumPairsChecked,Num_pairs_checked);
657 // #define PAIR_STATS
659 avg_time_to_next_check = avg_time_to_next_check / Num_pairs;
660 extern int Num_hull_pieces;
661 extern int Weapons_created;
662 // 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 ));
663 // 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) ));
664 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) ));
665 pairs_not_created = 0;
670 // What percent of the pairs did we check?
671 // FYI: (n*(n-1))/2 is the total number of checks required for comparing n objects.
673 // if ( org_pairs > 1 ) {
674 // Object_checked_percentage = (i2fl(n)*100.0f) / i2fl(org_pairs);
676 // Object_checked_percentage = 0.0f;
681 // See if two lines intersect by doing recursive subdivision.
682 // Bails out if larger distance traveled is less than sum of radii + 1.0f.
683 int collide_subdivide(vector *p0, vector *p1, float prad, vector *q0, vector *q1, float qrad)
685 float a_dist, b_dist, ab_dist;
687 a_dist = vm_vec_dist(p0, p1);
688 b_dist = vm_vec_dist(q0, q1);
690 ab_dist = vm_vec_dist(p1, q1);
692 // See if their spheres intersect
693 if (ab_dist < a_dist + b_dist + prad + qrad) {
694 if (ab_dist < prad + qrad)
696 else if (vm_vec_dist(p0, q0) < prad + qrad)
698 else if (max(a_dist, b_dist) < prad + qrad + 1.0f)
704 vm_vec_avg(&pa, p0, p1);
705 vm_vec_avg(&qa, q0, q1);
706 r1 = collide_subdivide(p0, &pa, prad, q0, &qa, qrad);
708 r2 = collide_subdivide(&pa, p1, prad, &qa, q1, qrad);
718 // Return true if object A is expected to collide with object B within time duration
719 // For purposes of this check, the first object moves from current location to predicted
720 // location. The second object is assumed to be where it will be at time duration, NOT
721 // where it currently is.
722 // radius_scale is used to control the precision of the check.
723 // If 0.0, then use polygon models to perform check, slow and accurate
724 // If !0.0, then use as a scale on the radius of the objects. 1.0 is Descent style
725 // collisions. Larger values can be used to be sloppy about the collisions which
726 // is useful if a moving object wants to prevent a collision.
727 int objects_will_collide(object *A, object *B, float duration, float radius_scale)
734 vm_vec_scale_add2(&A_future.pos, &A->phys_info.vel, duration);
736 if (radius_scale == 0.0f) {
737 return ship_check_collision_fast(B, &A_future, &hitpos );
739 float size_A, size_B, dist, r;
740 vector nearest_point;
742 size_A = A->radius * radius_scale;
743 size_B = B->radius * radius_scale;
745 // If A is moving, check along vector.
746 if (A->phys_info.speed != 0.0f) {
747 r = find_nearest_point_on_line(&nearest_point, &A->pos, &A_future.pos, &B->pos);
749 nearest_point = A->pos;
751 nearest_point = A_future.pos;
753 dist = vm_vec_dist_quick(&B->pos, &nearest_point);
754 return (dist < size_A + size_B);
756 return vm_vec_dist_quick(&B->pos, &A->pos) < size_A + size_B;
761 // Return true if the vector from *start_pos to *end_pos is within objp->radius*radius_scale of *objp
762 int vector_object_collision(vector *start_pos, vector *end_pos, object *objp, float radius_scale)
765 vector nearest_point;
767 r = find_nearest_point_on_line(&nearest_point, start_pos, end_pos, &objp->pos);
768 if ((r >= 0.0f) && (r <= 1.0f)) {
769 dist = vm_vec_dist_quick(&objp->pos, &nearest_point);
771 return (dist < objp->radius * radius_scale);
776 // Returns TRUE if the weapon will never hit the other object.
777 // If it can it predicts how long until these two objects need
778 // to be checked and fills the time in in current_pair.
779 int weapon_will_never_hit( object *weapon, object *other, obj_pair * current_pair )
782 Assert( weapon->type == OBJ_WEAPON );
784 // mprintf(( "Frame: %d, Weapon=%d, Other=%d, pair=$%08x\n", G3_frame_count, OBJ_INDEX(weapon), OBJ_INDEX(other), current_pair ));
787 // Do some checks for weapons that don't turn
788 if ( !(Weapon_info[Weapons[weapon->instance].weapon_info_index].wi_flags & WIF_TURNS) ) {
790 // This first check is to see if a weapon is behind an object, and they
791 // are heading in opposite directions. If so, we don't need to ever check
792 // them again. This is only valid for weapons that don't turn.
795 if (Weapon_info[Weapons[weapon->instance].weapon_info_index].subtype == WP_LASER) {
796 vector velocity_rel_weapon;
797 vm_vec_sub(&velocity_rel_weapon, &weapon->phys_info.vel, &other->phys_info.vel);
798 vdot = -vm_vec_dot(&velocity_rel_weapon, &weapon->orient.fvec);
800 vdot = vm_vec_dot( &other->phys_info.vel, &weapon->phys_info.vel);
802 if ( vdot <= 0.0f ) {
803 // They're heading in opposite directions...
804 // check their positions
806 vm_vec_sub( &weapon2other, &other->pos, &weapon->pos );
807 float pdot = vm_vec_dot( &weapon->orient.fvec, &weapon2other );
808 if ( pdot <= -other->radius ) {
809 // The other object is behind the weapon by more than
810 // its radius, so it will never hit...
815 // FUTURE ENHANCEMENT IDEAS
817 // Given a laser does it hit a slow or not moving object
818 // in its life or the next n seconds? We'd actually need to check the
824 // This check doesn't care about orient, only looks at the maximum speed
825 // of the two objects, so it knows that in the next n seconds, they can't
826 // go further than some distance, so don't bother checking collisions for
827 // that time. This is very rough, but is so general that it works for
828 // everything and immidiately gets rid of a lot of cases.
830 if ( current_pair ) {
831 // Find the time it will take before these get within each others distances.
832 // tmp->next_check_time = timestamp(500);
833 //vector max_vel; //maximum foward velocity in x,y,z
835 float max_vel_weapon, max_vel_other;
836 max_vel_weapon = weapon->phys_info.max_vel.z;
837 max_vel_other = other->phys_info.max_vel.z;
838 if (max_vel_other < 10.0f) {
839 if ( vm_vec_mag_squared( &other->phys_info.vel ) > 100 ) {
840 // bump up velocity from collision
841 max_vel_other = vm_vec_mag( &other->phys_info.vel ) + 10.0f;
843 max_vel_other = 10.0f; // object may move from collision
847 // check weapon that does not turn against sphere expanding at ship maxvel
848 // compare (weeapon) ray with expanding sphere (ship) to find earliest possible collision time
849 // look for two time solutions to Xw = Xs, where Xw = Xw0 + Vwt*t Xs = Xs + Vs*(t+dt), where Vs*dt = radius of ship
850 // Since direction of Vs is unknown, solve for (Vs*t) and find norm of both sides
851 if ( !(Weapon_info[Weapons[weapon->instance].weapon_info_index].wi_flags & WIF_TURNS) ) {
852 vector delta_x, laser_vel;
853 float a,b,c, delta_x_dot_vl, delta_t;
854 float root1, root2, root, earliest_time;
856 vm_vec_sub( &delta_x, &weapon->pos, &other->pos );
857 vm_vec_copy_scale( &laser_vel, &weapon->orient.fvec, max_vel_weapon );
858 delta_t = (other->radius + 10.0f) / max_vel_other; // time to get from center to radius of other obj
859 delta_x_dot_vl = vm_vec_dotprod( &delta_x, &laser_vel );
861 a = max_vel_weapon*max_vel_weapon - max_vel_other*max_vel_other;
862 b = 2.0f * (delta_x_dot_vl - max_vel_other*max_vel_other*delta_t);
863 c = vm_vec_mag_squared( &delta_x ) - max_vel_other*max_vel_other*delta_t*delta_t;
865 float discriminant = b*b - 4.0f*a*c;
866 if ( discriminant < 0) {
870 root = fl_sqrt( discriminant );
871 root1 = (-b + root) / (2.0f * a) * 1000.0f; // get time in ms
872 root2 = (-b - root) / (2.0f * a) * 1000.0f; // get time in ms
875 // find earliest positive time
876 if ( root1 > root2 ) {
883 earliest_time = root1;
884 } else if (root2 > 0) {
885 // root1 < 0 and root2 > 0, so we're inside sphere and next check should be next frame
886 current_pair->next_check_time = timestamp(0); // check next time
889 // both times negative, so never collides
895 // check if possible collision occurs after weapon expires
896 if ( earliest_time > 1000*Weapons[weapon->instance].lifeleft )
899 // Allow one worst case frametime to elapse (~5 fps)
900 earliest_time -= 200.0f;
902 if (earliest_time > 100) {
903 current_pair->next_check_time = timestamp( fl2i(earliest_time) );
906 current_pair->next_check_time = timestamp(0); // check next time
912 float dist, max_vel, time;
914 max_vel = max_vel_weapon + max_vel_other;
916 // suggest that fudge factor for other radius be changed to other_radius + const (~10)
917 dist = vm_vec_dist( &other->pos, &weapon->pos ) - (other->radius + 10.0f);
919 time = (dist*1000.0f) / max_vel;
920 int time_ms = fl2i(time);
922 // check if possible collision occurs after weapon expires
923 if ( time_ms > 1000*Weapons[weapon->instance].lifeleft )
926 time_ms -= 200; // Allow at least one worst case frametime to elapse (~5 fps)
928 if ( time_ms > 100 ) { // If it takes longer than 1/10th of a second, then delay it
929 current_pair->next_check_time = timestamp(time_ms);
930 //mprintf(( "Delaying %d ms\n", time_ms ));
934 current_pair->next_check_time = timestamp(0); // check next time
942 // Return true if vector from *curpos to *goalpos intersects with object *goalobjp
943 // Else, return false.
944 // radius is radius of object moving from curpos to goalpos.
945 int pp_collide(vector *curpos, vector *goalpos, object *goalobjp, float radius)
949 Assert(goalobjp->type == OBJ_SHIP);
951 ship_model_start(goalobjp);
953 mc.model_num = Ships[goalobjp->instance].modelnum; // Fill in the model to check
954 mc.orient = &goalobjp->orient; // The object's orient
955 mc.pos = &goalobjp->pos; // The object's position
956 mc.p0 = curpos; // Point 1 of ray to check
957 mc.p1 = goalpos; // Point 2 of ray to check
958 mc.flags = MC_CHECK_MODEL | MC_CHECK_SPHERELINE;
963 ship_model_stop(goalobjp);
968 // Setup and call pp_collide for collide_predict_large_ship
969 // Returns true if objp will collide with objp2 before it reaches goal_pos.
970 int cpls_aux(vector *goal_pos, object *objp2, object *objp)
974 radius = objp->radius;
975 if (1.5f * radius < 70.0f)
980 if (pp_collide(&objp->pos, goal_pos, objp2, radius))
986 // Return true if objp will collide with some large object.
987 // Don't check for an object this ship is docked to.
988 int collide_predict_large_ship(object *objp, float distance)
991 vector cur_pos, goal_pos;
995 sip = &Ship_info[Ships[objp->instance].ship_info_index];
998 if (objp->type == OBJ_SHIP) {
999 ai_info *aip = &Ai_info[Ships[objp->instance].ai_index];
1000 if (aip->dock_objnum != -1)
1001 dock_objp = &Objects[aip->dock_objnum];
1004 cur_pos = objp->pos;
1006 vm_vec_scale_add(&goal_pos, &cur_pos, &objp->orient.fvec, distance);
1008 for ( objp2 = GET_FIRST(&obj_used_list); objp2 != END_OF_LIST(&obj_used_list); objp2 = GET_NEXT(objp2) ) {
1009 if ((objp != objp2) && (objp2->type == OBJ_SHIP)) {
1010 if (Ship_info[Ships[objp2->instance].ship_info_index].flags & (SIF_BIG_SHIP | SIF_HUGE_SHIP)) {
1011 if (objp2 == dock_objp)
1014 if (cpls_aux(&goal_pos, objp2, objp))
1017 } else if (!(sip->flags & (SIF_BIG_SHIP | SIF_HUGE_SHIP)) && (objp2->type == OBJ_ASTEROID)) {
1018 if (vm_vec_dist_quick(&objp2->pos, &objp->pos) < (distance + objp2->radius)*2.5f) {
1023 d1 = 2.5f * distance + objp2->radius;
1024 count = (int) (d1/(objp2->radius + objp->radius)); // Scale up distance, else looks like there would be a collision.
1026 vm_vec_normalized_dir(&delvec, &goal_pos, &cur_pos);
1027 vm_vec_scale(&delvec, d1/count);
1029 for (; count>0; count--) {
1030 if (vm_vec_dist_quick(&pos, &objp2->pos) < objp->radius + objp2->radius)
1032 vm_vec_add2(&pos, &delvec);
1041 // function to iterate through all object collision pairs looking for weapons
1042 // which could be deleted since they are not going to hit anything. Passed into this
1043 // function is a 'time' parameter used as watermark for which weapons to check.
1045 #define CRW_NO_OBJECT -1
1046 #define CRW_NO_PAIR 0
1047 #define CRW_IN_PAIR 1
1048 #define CRW_CAN_DELETE 2
1050 #define CRW_MAX_TO_DELETE 4
1052 char crw_status[MAX_WEAPONS];
1054 void crw_check_weapon( int weapon_num, int collide_next_check )
1056 float next_check_time;
1059 wp = &Weapons[weapon_num];
1061 // if this weapons life left > time before next collision, then we cannot remove it
1062 crw_status[WEAPON_INDEX(wp)] = CRW_IN_PAIR;
1063 next_check_time = ((float)(timestamp_until(collide_next_check)) / 1000.0f);
1064 if ( wp->lifeleft < next_check_time )
1065 crw_status[WEAPON_INDEX(wp)] = CRW_CAN_DELETE;
1068 int collide_remove_weapons( )
1071 int i, num_deleted, oldest_index, j, loop_count;
1074 // setup remove_weapon array. assume we can remove it.
1075 for (i = 0; i < MAX_WEAPONS; i++ ) {
1076 if ( Weapons[i].objnum == -1 )
1077 crw_status[i] = CRW_NO_OBJECT;
1079 crw_status[i] = CRW_NO_PAIR;
1082 // first pass is to see if any of the weapons don't have collision pairs.
1084 opp = &pair_used_list;
1086 while( opp != NULL ) {
1087 // for each collide pair, if the two objects can still collide, then set the remove_weapon
1088 // parameter for the weapon to 0. need to check both parameters
1089 if ( opp->a->type == OBJ_WEAPON )
1090 crw_check_weapon( opp->a->instance, opp->next_check_time );
1092 if ( opp->b->type == OBJ_WEAPON )
1093 crw_check_weapon( opp->b->instance, opp->next_check_time );
1098 // for each weapon which could be removed, delete the object
1100 for ( i = 0; i < MAX_WEAPONS; i++ ) {
1101 if ( crw_status[i] == CRW_CAN_DELETE ) {
1102 Assert( Weapons[i].objnum != -1 );
1103 obj_delete( Weapons[i].objnum );
1111 // if we didn't remove any weapons, try to the N oldest weapons. first checking for pairs, then
1112 // checking for oldest weapons in general. We will go through the loop a max of 2 times. first time
1113 // through, we check oldest weapons with pairs, next time through, for oldest weapons.
1116 for ( j = 0; j < CRW_MAX_TO_DELETE; j++ ) {
1117 oldest_time = 1000.0f;
1119 for (i = 0; i < MAX_WEAPONS; i++ ) {
1120 if ( Weapons[i].objnum == -1 ) // shouldn't happen, but this is the safe thing to do.
1122 if ( ((loop_count || crw_status[i] == CRW_NO_PAIR)) && (Weapons[i].lifeleft < oldest_time) ) {
1123 oldest_time = Weapons[i].lifeleft;
1127 if ( oldest_index != -1 ) {
1128 obj_delete(Weapons[oldest_index].objnum);
1133 // if we deleted some weapons, then we can break
1138 } while ( loop_count < 2);
1144 void set_hit_struct_info(collision_info_struct *hit, mc_info *mc, int submodel_rot_hit)
1146 hit->edge_hit = mc->edge_hit;
1147 hit->hit_pos = mc->hit_point_world;
1148 hit->hit_time = mc->hit_dist;
1149 hit->submodel_num = mc->hit_submodel;
1151 hit->submodel_rot_hit = submodel_rot_hit;