2 * $Logfile: /Freespace2/code/Ship/AiBig.cpp $
7 * C module for AI code related to large ships
10 * Revision 1.3 2002/06/01 07:12:33 relnev
11 * a few NDEBUG updates.
13 * removed a few warnings.
15 * Revision 1.2 2002/05/07 03:16:51 theoddone33
16 * The Great Newline Fix
18 * Revision 1.1.1.1 2002/05/03 03:28:10 root
22 * 13 8/31/99 4:24p Andsager
23 * Reduce collisions when attacking big ships.
25 * 12 7/19/99 2:18p Mikeb
28 * 11 7/19/99 2:11p Mikeb
29 * DA: sometimes big_ship_attack_normal is not known
31 * 10 6/14/99 3:21p Andsager
32 * Allow collisions between ship and its debris. Fix up collision pairs
33 * when large ship is warping out.
35 * 9 6/02/99 5:41p Andsager
36 * Reduce range of secondary weapons not fired from turrets in nebula.
37 * Reduce range of beams fired from turrrets in nebula
39 * 8 5/13/99 2:31p Jamesa
40 * DA: Temp fix when attacking subsys of big ship and BS is blown up.
42 * 7 5/06/99 11:46a Andsager
43 * Bug fixes. Don't get into illegal strafe submode. Don't choose turret
44 * enemy objnum for beam protected.
46 * 6 4/23/99 12:01p Johnson
49 * 5 4/20/99 3:40p Andsager
50 * Changes to big ship ai. Uses bounding box as limit where to fly to
53 * 4 4/16/99 5:54p Dave
54 * Support for on/off style "stream" weapons. Real early support for
55 * target-painting lasers.
57 * 3 10/13/98 9:29a Dave
58 * Started neatening up freespace.h. Many variables renamed and
59 * reorganized. Added AlphaColors.[h,cpp]
61 * 2 10/07/98 10:53a Dave
64 * 1 10/07/98 10:51a Dave
66 * 77 5/25/98 12:12a Mike
67 * Improve big ship avoidance to avoid big ships when in a nearby dock
68 * mode. Fixes very dumb looking behavior in sm2-01a. Verified sm1-08a
69 * not too dumb at start.
71 * 76 5/23/98 2:38a Mike
72 * Improve balance of cheat-firing Synaptics.
74 * 75 5/23/98 12:40a Mike
75 * Hook for Delta wing to fire Synaptic bombs in sm3-09a.
77 * 74 5/22/98 12:08p Mike
78 * Force reset of aspect locking when AI ships switch banks due to
79 * good-time-to-unload-secondaries
81 * 73 5/21/98 1:25p Lawrance
82 * Fix exception in ai_bpap() when no verts are in closest octant
84 * 72 5/21/98 9:57a Mike
85 * Massively improve firing of bombs at big ships. Improve willingness to
86 * take incoming fire to deliver bomb. Make a little easier to gain
89 * 71 5/12/98 10:06a Mike
90 * Fix a jillion bugs preventing ships from firing bombs at Lucifer in
93 * 70 5/10/98 11:30p Mike
94 * Better firing of bombs, less likely to go into strafe mode.
96 * 69 5/10/98 3:41a Lawrance
97 * Fix bug that was preventing ships from leaving strafe mode
99 * 68 5/08/98 4:39p Mike
100 * Make ships match bank when attacking large ships.
102 * 67 5/07/98 11:59p Mike
103 * Remove unneeded code, computation of num_verts.
105 * 66 4/29/98 5:01p Mike
106 * Large overhaul in how turrets fire.
108 * 65 4/27/98 11:59p Mike
109 * Intermediate checkin. Getting big ship turrets firing at big ships to
110 * use pick_big_attack_point.
112 * 64 4/23/98 12:32a Mike
113 * Fix bogus math which looked at (1-fov) instead of fov.
115 * 63 4/13/98 4:52p Allender
116 * remove AI_frametime and us flFrametime instead. Make lock warning work
117 * in multiplayer for aspect seeking missiles. Debris fixups
119 * 62 4/13/98 3:27p Lawrance
120 * Fix bug that caused ships to leave strafe mode right away since they
121 * hadn't taken damage for a while
123 * 61 4/12/98 2:02p Mike
124 * Make small ships avoid big ships.
125 * Turn on Collide_friendly flag.
127 * 60 4/01/98 9:21p John
128 * Made NDEBUG, optimized build with no warnings or errors.
130 * 59 3/25/98 12:00a Allender
131 * MK: make sure that output from function gets a valid valud (ai_pbap I
134 * 58 3/24/98 10:07p Adam
135 * AL: Add another Assert() to try and catch bogus wp->big_attack_point
137 * 57 3/24/98 9:56p Adam
138 * AL: Assert that local_attack_point is valid in ai_bpap
140 * 56 3/21/98 3:36p Mike
141 * Fix/optimize attacking of big ships.
143 * 55 3/16/98 5:17p Mike
144 * Make ships not get stuck on big ships when attacking.
146 * 54 3/16/98 12:03a Mike
147 * Add support for kamikaze mode. Add AIF_NO_DYNAMIC which means
148 * relentlessly pursue current goal.
150 * 53 3/12/98 4:04p Lawrance
151 * Leave strafe mode if haven't been hit for a while and no enemy
152 * fighter/bombers are close by.
154 * 52 3/09/98 5:12p Mike
155 * Make sure Pl_objp uses are valid.
156 * Throw asteroids at ships in asteroid field, not "Gal"
157 * Support ships warp out if no goals after 30 seconds.
159 * 51 3/03/98 11:51p Lawrance
160 * Ensure target is a ship before looking at SIF flags
162 * 50 3/02/98 11:35a Mike
163 * Fix logic with ai_do_default_behavior -- return after call.
165 * 49 2/19/98 7:37p Lawrance
166 * Fix bug that was causing problems with subsystem path following.
168 * 48 2/14/98 3:38p Mike
169 * Make bombs have arm time, drop for 1/2 second, have hull_strength.
170 * Make them not fired until closer to target.
172 * 47 2/13/98 3:56p Mike
173 * Make ships more likely to stick to player orders, not get so distracted
174 * by getting hit by someone else.
176 * 46 2/11/98 4:30p Lawrance
177 * Improve disarm/disable behavior.
179 * 45 2/11/98 1:16a Mike
180 * Mods to AI behavior to make it harder to stay on a ship's tail. Not
181 * too much improvement.
183 * 44 2/05/98 12:51a Mike
184 * Early asteroid stuff.
186 * 43 1/30/98 11:28a Comet
187 * Fix indexing problem into verts in ai_bpap()
189 * 42 1/29/98 10:46p Mike
190 * In ai_big_pick_attack_point, handle case of octant with no points.
192 * 41 1/29/98 1:39p Mike
193 * Better heat seeking homing on big ships.
195 * 40 1/27/98 4:18p Mike
196 * Not fire weapons too early when attacking large ships. Aspect lock
197 * take proper amount of time for AI ships.
199 * 39 1/22/98 5:14p Lawrance
200 * clean up ai_big code, clear path info when stop attacking a subsystem
202 * 38 1/20/98 11:41p Mike
203 * Ships use new system of preferred big weapons to fire. Also, support
204 * AIF_UNLOAD_SECONDARIES which means fire as fast as possible.
206 * 37 1/20/98 9:47a Mike
207 * Suppress optimized compiler warnings.
208 * Some secondary weapon work.
210 * 36 1/17/98 4:45p Mike
211 * Better support for AI selection of secondary weapons.
213 * 35 1/16/98 3:57p Mike
214 * Clean up some bugs with attacking of protected ships. Make turrets
215 * only fire at targets that are within range.
217 * 34 1/16/98 11:32a Mike
218 * Fix bug when a ship is attacking a dead subsystem on a protected ship.
220 * 33 1/07/98 1:32p Lawrance
221 * Remove some nprintf output
223 * 32 1/07/98 1:21p Sandeep
224 * Fix bug where accessing uninited pointer
226 * 31 1/06/98 6:58p Lawrance
227 * Attack turrets (sometimes) when fired upon while attacking a ship.
229 * 30 12/31/97 6:28p Lawrance
230 * Improve attacking subsystems on moving ships.
232 * 29 12/31/97 4:16p Lawrance
233 * Use different fov's for attacking subsystems depending if ship is
236 * 28 12/31/97 4:05p Mike
237 * Support for all teams optionally attacking all teams.
238 * Lead big ships when attacking their hull.
240 * 27 12/31/97 12:26p Lawrance
241 * Don't enter strafe mode for transports, fix bug that prevented strafe
242 * mode from getting entered.
244 * 26 12/30/97 5:20p Mike
245 * Don't fire secondaries at a protected ship if its hull is very weak.
247 * 25 12/30/97 4:26p Lawrance
248 * Take out some debug statements
250 * 24 12/15/97 7:16p Lawrance
251 * improving subsystem attacking
253 * 23 12/02/97 11:58a Lawrance
254 * avoid during strafe mode only when endangered by a weapon
256 * 22 12/01/97 5:11p Lawrance
257 * make strafe mode more effective... slow down when approaching and use
258 * afterburner in avoids
260 * 21 11/27/97 4:21p Lawrance
261 * set submode to -1 when switching to AIM_NONE from AIM_STRAFE
263 * 20 11/24/97 2:27a Lawrance
264 * if attacking a big ship and moving very slow, enter strafe mode if
265 * enemy fighter/bombers are close by
267 * 19 11/14/97 11:27a Johnson
268 * if goal_objnum is -1, and in STRAFE, return 1 from
269 * ai_maybe_follow_subsys_path(), so break out of STRAFE code
271 * 18 11/13/97 11:51a Johnson
272 * ALAN: comment out Int3() in AiBig... need to test on my own machine
274 * 17 11/12/97 11:51p Lawrance
275 * only check target_objnum == goal_objnum when following path
277 * 16 11/12/97 11:01p Lawrance
278 * change call to ai_find_path()
279 * ensure goal_objnum == target_objnum in STRAFE
281 * 15 11/12/97 11:18a Lawrance
282 * fix bug in path following of subsystems
284 * 14 11/11/97 5:22p Mike
285 * Don't allow ships to attack navbuoys.
286 * Make ships lead big ships with dumbfire.
287 * Make ships smarter about leaving evade weapon mode.
288 * Fix a couple Assert() bugs.
290 * 13 11/06/97 6:27p Lawrance
291 * fix bug that was messing up retreat point in STRAFE mode
293 * 12 11/06/97 4:53p Mike
294 * Limit number of ships that can simultaneously attack another. Make
295 * turrets inherit AI class from parent ship.
297 * 11 11/06/97 12:27a Mike
298 * Better avoid behavior.
299 * Modify ai_turn_towards_vector() to take a flag parameter.
301 * 10 11/02/97 10:55p Lawrance
302 * removed some unused code, added some comments
304 * 9 11/01/97 4:01p Mike
305 * Adapt to new ai_find_path().
307 * 8 10/31/97 11:24a Lawrance
308 * If taget changes from a big ship to small ship while in AIM_STRAFE,
309 * switch to AIM_CHASE
311 * 7 10/30/97 10:06p Lawrance
312 * chg some timing values so ship will reach retreat point
314 * 6 10/30/97 9:17p Lawrance
315 * work on getting AIM_STRAFE working well with disable/disarm, try to
318 * 5 10/30/97 12:32a Lawrance
319 * further work on AIM_STRAFE
321 * 4 10/29/97 6:25p Lawrance
322 * add AIM_STRAFE functionality
324 * 3 10/26/97 4:19p Lawrance
325 * added ai_get_weapon_dist()
327 * 2 10/26/97 3:24p Lawrance
328 * split off large ship ai code into AiBig.cpp
335 #include "linklist.h"
345 #include "floating.h"
347 #include "freespace.h"
349 #include "missiongoals.h"
350 #include "missionlog.h"
355 #include "hudmessage.h"
356 #include "missionmessage.h"
357 #include "cmeasure.h"
358 #include "staticrand.h"
359 #include "multimsgs.h"
360 #include "afterburner.h"
364 #include "missionparse.h"
367 #pragma optimize("", off)
368 #pragma auto_inline(off)
371 #define SCAN_FIGHTERS_INTERVAL 2000 // how often an AI fighter/bomber should scan for enemy fighter/bombers
372 // if sitting still and pounding on a big ship. If enemy fighters are
373 // close ( < ENTER_STRAFE_THREAT_DIST ), then enter AIM_STRAFE
375 #define ENTER_STRAFE_THREAT_DIST_SQUARED 360000 // use squared distance, instead of 600
377 #define MIN_DOT_TO_ATTACK_SUBSYS 0.7f
378 #define MIN_DOT_TO_ATTACK_MOVING_SUBSYS 0.97f
380 // AI BIG MAGIC NUMBERS
381 #define STRAFE_RETREAT_COLLIDE_TIME 2.0 // when anticipated collision time is less than this, begin retreat
382 #define STRAFE_RETREAT_COLLIDE_DIST 100 // when perpendicular distance to *surface* is less than this, begin retreat
383 #define STRAFE_RETREAT_BOX_DIST 300 // distance beyond the bounding box to retreat
385 #define EVADE_BOX_BASE_DISTANCE 300 // standard distance to end evade submode
386 #define EVADE_BOX_MIN_DISTANCE 200 // minimun distance to end evade submode, after long time
388 #define ATTACK_STOP_DISTANCE 150 // when distance to target is less than this, put on brakes
390 #define ATTACK_COLLIDE_BASE_DIST 300 // absolute distance at which to begin checking for possible collision
391 #define ATTACK_COLLIDE_AVOID_DIST 60 // perpendicular distance to attack surface at which begin avoiding
392 #define ATTACK_COLLIDE_AVOID_TIME 1.0 // anticipated collision time at which to begin evade
393 #define ATTACK_COLLIDE_SLOW_DIST 150 // perpendicular distance to attack surface at which begin slowing down
394 #define ATTACK_COLLIDE_SLOW_TIME 1.5 // anticipated collision time at which to begin slowing down
397 // forward declarations
398 void ai_big_evade_ship();
399 void ai_big_chase_attack(ai_info *aip, ship_info *sip, vector *enemy_pos, float dist_to_enemy);
400 void ai_big_avoid_ship();
401 int ai_big_maybe_follow_subsys_path(int do_dot_check=1);
403 extern int model_which_octant_distant_many( vector *pnt, int model_num,matrix *model_orient, vector * model_pos, polymodel **pm, int *octs);
404 extern void compute_desired_rvec(vector *rvec, vector *goal_pos, vector *cur_pos);
405 extern void big_ship_collide_recover_start(object *objp, object *big_objp, vector *collide_pos, vector *collision_normal);
408 // Called by ai_big_pick_attack_point.
409 // Generates a random attack point.
410 // If truly_random flag set (haha), then generate a pretty random number. Otherwise, generate a static rand which
411 // tends to not change from frame to frame.
412 // Try four times and choose nearest point to increase chance of getting a good point.
413 void ai_bpap(object *objp, vector *attacker_objp_pos, vector *attacker_objp_fvec, vector *attack_point, vector *local_attack_point, float fov, float weapon_travel_dist, vector *surface_normal)
416 vector result_point, best_point;
423 best_point = objp->pos;
424 nearest_dist = weapon_travel_dist;
426 model_which_octant_distant_many(attacker_objp_pos, Ships[objp->instance].modelnum, &objp->orient, &objp->pos, &pm, octs);
428 num_tries = (int) (vm_vec_dist(&objp->pos, attacker_objp_pos)/objp->radius);
433 num_tries = 4 - num_tries;
435 // Index #0 is best one.
436 if ( pm->octants[octs[0]].verts ) {
437 *local_attack_point = *pm->octants[octs[0]].verts[0]; // Set just in case it doesn't get set below.
439 vm_vec_zero(local_attack_point);
442 for (q=0; q<4; q++) {
443 octp = &pm->octants[octs[q]];
444 if (octp->nverts > 0) {
446 if (num_tries > octp->nverts)
447 num_tries = octp->nverts;
449 if (num_tries > octp->nverts)
450 num_tries = octp->nverts;
454 for (i=0; i<num_tries; i++) {
459 index = (int) (frand() * (octp->nverts));
461 rel_point = *octp->verts[index];
462 vm_vec_unrotate(&result_point, &rel_point, &objp->orient);
463 vm_vec_add2(&result_point, &objp->pos);
465 dist = vm_vec_normalized_dir(&v2p, &result_point, attacker_objp_pos);
466 dot = vm_vec_dot(&v2p, attacker_objp_fvec);
469 if (dist < nearest_dist) {
472 best_point = result_point;
473 *local_attack_point = rel_point;
474 Assert( !vm_is_vec_nan(local_attack_point) );
475 if (dot > (1.0f + fov)/2.0f) // If this point is quite good, quit searching for a better one.
484 *attack_point = best_point;
486 // Cast from attack_objp_pos to local_attack_pos and check for nearest collision.
487 // If no collision, cast to (0,0,0) [center of big ship]** [best_point initialized to 000]
489 // do in world coords to get attack point, then translate to local for local_attack_point
490 vector attack_dir, end_point, temp;
492 dist = vm_vec_normalized_dir(&attack_dir, attack_point, attacker_objp_pos);
495 vm_vec_scale_add(&end_point, attack_point, &attack_dir, 30.0f);
497 vm_vec_scale_add(&end_point, attack_point, attacker_objp_fvec, 30.0f);
501 mc.model_num = Ships[objp->instance].modelnum;
502 mc.orient = &objp->orient;
504 mc.p0 = attacker_objp_pos;
506 mc.flags = MC_CHECK_MODEL;
510 if (mc.num_hits > 0) {
511 *attack_point = mc.hit_point_world;
512 vm_vec_sub(&temp, attack_point, &objp->pos);
513 vm_vec_rotate(local_attack_point, &temp, &objp->orient);
514 if (surface_normal) {
515 vm_vec_unrotate(surface_normal, &mc.hit_normal, &objp->orient);
518 vm_vec_zero(local_attack_point);
519 *attack_point = objp->pos;
520 if (surface_normal) {
521 vm_vec_zero(surface_normal);
526 // Stuff a point to attack based on nearest octant.
527 // If no points in that octant, leave attack_point unmodified.
529 // Note: Default value for fov is 1.0f 1.0f means don't use fov parameter.
530 // If fov != 1.0f, try up to four times to find a point that's in the field of view.
531 void ai_big_pick_attack_point_turret(object *objp, ship_subsys *ssp, vector *gpos, vector *gvec, vector *attack_point, float fov, float weapon_travel_dist)
533 if (!timestamp_elapsed(ssp->turret_pick_big_attack_point_timestamp)) {
535 vm_vec_unrotate(&result_point, &ssp->turret_big_attack_point, &objp->orient);
536 vm_vec_add(attack_point, &result_point, &objp->pos);
538 vector local_attack_point;
539 ssp->turret_pick_big_attack_point_timestamp = timestamp(2000 + (int) (frand()*500.0f));
540 ai_bpap(objp, gpos, gvec, attack_point, &local_attack_point, fov, weapon_travel_dist, NULL);
541 ssp->turret_big_attack_point = local_attack_point;
545 // Stuff a point to attack based on nearest octant.
546 // If no points in that octant, leave attack_point unmodified.
548 // Note: Default value for fov is 1.0f 1.0f means don't use fov parameter.
549 // If fov != 1.0f, try up to four times to find a point that's in the field of view.
550 // Note, attacker_objp can be a ship or a weapon.
551 void ai_big_pick_attack_point(object *objp, object *attacker_objp, vector *attack_point, float fov)
553 Assert(objp->instance > -1);
554 Assert(objp->type == OBJ_SHIP);
556 vector local_attack_point;
558 switch (attacker_objp->type) {
560 ai_info *attacker_aip;
561 attacker_aip = &Ai_info[Ships[attacker_objp->instance].ai_index];
562 if (!timestamp_elapsed(attacker_aip->pick_big_attack_point_timestamp)) {
565 vm_vec_unrotate(&result_point, &attacker_aip->big_attack_point, &objp->orient);
566 vm_vec_add(attack_point, &result_point, &objp->pos);
571 attacker_aip->pick_big_attack_point_timestamp = timestamp(2000 + (int) (frand()*500.0f));
575 weapon *wp = &Weapons[attacker_objp->instance];
577 if (!timestamp_elapsed(wp->pick_big_attack_point_timestamp)) {
580 vm_vec_unrotate(&result_point, &wp->big_attack_point, &objp->orient);
581 vm_vec_add(attack_point, &result_point, &objp->pos);
585 wp->pick_big_attack_point_timestamp = timestamp(2000 + (int) (frand()*500.0f));
591 // checks valid line to target
592 vector surface_normal;
593 ai_bpap(objp, &attacker_objp->pos, &attacker_objp->orient.fvec, attack_point, &local_attack_point, fov, 99999.9f, &surface_normal);
595 switch (attacker_objp->type) {
597 ai_info *attacker_aip;
598 // if we can't find a new local_attack_point don't change local_attack_point
599 if (vm_vec_mag_squared(&local_attack_point) < 1) {
603 attacker_aip = &Ai_info[Ships[attacker_objp->instance].ai_index];
604 attacker_aip->big_attack_point = local_attack_point;
605 attacker_aip->big_attack_surface_normal = surface_normal;
609 weapon *wp = &Weapons[attacker_objp->instance];
610 wp->big_attack_point = local_attack_point;
611 Assert( !vm_is_vec_nan(&wp->big_attack_point) );
619 // Handler for SM_EVADE submode ( called from ai_big_chase() )
620 void ai_big_evade_ship()
622 vector player_pos, enemy_pos;
624 ship *shipp = &Ships[Pl_objp->instance];
625 ai_info *aip = &Ai_info[shipp->ai_index];
626 vector randvec, semi_enemy_pos;
628 ai_set_positions(Pl_objp, En_objp, aip, &player_pos, &enemy_pos);
630 dist = vm_vec_dist_quick(&player_pos, &enemy_pos);
631 vm_vec_rand_vec_quick(&randvec);
632 if ((Missiontime>>14) & 1) {
633 vm_vec_scale_add(&semi_enemy_pos, &enemy_pos, &randvec, dist/2.0f);
634 aip->prev_goal_point = semi_enemy_pos;
636 semi_enemy_pos = aip->prev_goal_point;
639 accelerate_ship(aip, 1.0f - ((Missiontime>>8) & 0x3f)/128.0f );
640 turn_away_from_point(Pl_objp, &semi_enemy_pos, 0.0f);
645 box_dist = get_world_closest_box_point_with_delta(&box_vec, En_objp, &player_pos, &is_inside, EVADE_BOX_BASE_DISTANCE);
646 if (box_dist > EVADE_BOX_BASE_DISTANCE) {
647 aip->submode = SM_ATTACK;
648 aip->submode_start_time = Missiontime;
649 } else if ((box_dist > EVADE_BOX_MIN_DISTANCE) && (Missiontime - aip->submode_start_time > i2f(5)) ) {
650 aip->submode = SM_ATTACK;
651 aip->submode_start_time = Missiontime;
656 /* if (dist > 4*En_objp->radius) {
657 aip->submode = SM_ATTACK;
658 aip->submode_start_time = Missiontime;
659 } else if (dist > En_objp->radius) {
660 if (Missiontime - aip->submode_start_time > i2f(5)) {
661 aip->submode = SM_ATTACK;
662 aip->submode_start_time = Missiontime;
667 // Handler for SM_AVOID submode ( called from ai_big_chase() )
668 void ai_big_avoid_ship()
673 // reset path following information
674 void ai_big_subsys_path_cleanup(ai_info *aip)
676 if ( aip->ai_flags & AIF_ON_SUBSYS_PATH ) {
677 aip->ai_flags &= ~AIF_ON_SUBSYS_PATH;
678 aip->path_goal_dist = -1;
679 aip->path_start = -1;
681 aip->path_length = 0;
685 // Maybe Pl_objp needs to follow a path to get in line-of-sight to a subsystem
686 // input: do_dot_check => default value 0, flag to indicate whether check should be done to ensure
687 // subsystem is within certain field of view. We don't want to check fov when
688 // strafing, since ship is weaving to avoid turret fire
689 int ai_big_maybe_follow_subsys_path(int do_dot_check)
692 float dot = 1.0f, min_dot;
695 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
696 target_objp = &Objects[aip->target_objnum];
698 if ( (aip->targeted_subsys != NULL) && (aip->target_objnum >= 0) && (aip->targeted_subsys->system_info->path_num >= 0) ) {
700 int subsys_path_num, subsys_in_sight, checked_sight;
703 pm = model_get( Ships[Pl_objp->instance].modelnum );
705 // If attacking a subsystem, ensure that we have an unobstructed line of sight... if not, then move
706 // towards path linked to subsystem
707 subsys_in_sight = 0; // assume Pl_objp doesn't have line of sight to subys
709 // only check for subsystem sight every N milliseconds
711 if ( timestamp_elapsed(aip->path_subsystem_next_check) ) {
712 vector geye, gsubpos;
715 aip->path_subsystem_next_check = timestamp(1500);
717 // get world pos of eye (stored in geye)
718 ep = &(pm->view_positions[0] );
719 model_find_world_point( &geye, &ep->pnt, Ships[Pl_objp->instance].modelnum, 0, &Pl_objp->orient, &Pl_objp->pos );
721 // get world pos of subsystem
722 vm_vec_unrotate(&gsubpos, &aip->targeted_subsys->system_info->pnt, &En_objp->orient);
723 vm_vec_add2(&gsubpos, &En_objp->pos);
727 // Calc dot between subsys normal (based on using path info), and subsys_to_eye vector. This is
728 // useful later when we want to decide whether we have a realistic line-of-sight to the subsystem.
729 vector subsys_normal, subsys_to_eye;
730 if ( do_dot_check ) {
731 if ( !ship_return_subsys_path_normal(&Ships[target_objp->instance], aip->targeted_subsys, &gsubpos, &subsys_normal) ) {
732 vm_vec_normalized_dir(&subsys_to_eye, &geye, &gsubpos);
733 dot = vm_vec_dot(&subsys_normal, &subsys_to_eye);
737 if ( ship_subsystem_in_sight(En_objp, aip->targeted_subsys, &geye, &gsubpos, 1) ) {
742 // check if subsystem not in sight
743 min_dot = (target_objp->phys_info.fspeed > 5.0f?MIN_DOT_TO_ATTACK_MOVING_SUBSYS:MIN_DOT_TO_ATTACK_SUBSYS);
744 if ( (checked_sight && ((!subsys_in_sight) || (dot < min_dot)) ) ) {
746 aip->path_goal_dist = 5;
747 subsys_path_num = aip->targeted_subsys->system_info->path_num;
748 if ( (aip->path_start) == -1 || (aip->mp_index != subsys_path_num) ) {
749 // maybe create a new path
750 if ( subsys_path_num >= 0 ) {
751 Assert(aip->target_objnum >= 0);
752 ai_find_path(Pl_objp, aip->target_objnum, subsys_path_num, 0, 1);
753 if ( aip->path_start >= 0 ) {
754 aip->ai_flags |= AIF_ON_SUBSYS_PATH;
760 if ( checked_sight && subsys_in_sight && (dot > min_dot) ) {
761 // we've got a clear shot, stay here for a bit
762 aip->path_subsystem_next_check = timestamp_rand(5000,8000);
765 // If there is a path that we are tracking, see if ship has gotten to within
766 // aip->path_goal_dist units. If so, then ship can stop following the path. This
767 // is required since we don't want to follow the path all the way to the subsystem,
768 // and we want ships to stop different distances from their path destination
769 if ( aip->path_length > 0 ) {
773 Assert(aip->path_length >= 2);
774 dist = vm_vec_dist_quick(&Path_points[aip->path_start+aip->path_length-2].pos, &Pl_objp->pos);
776 if ( aip->path_cur >= (aip->path_start+aip->path_length-1) ) {
780 min_dot = (target_objp->phys_info.fspeed > 5.0f?MIN_DOT_TO_ATTACK_MOVING_SUBSYS:MIN_DOT_TO_ATTACK_SUBSYS);
781 if ( (checked_sight && subsys_in_sight) && (dot > min_dot) ) {
785 // if we've reached the destination, then we can stop following the path
786 if ( path_done || ( dist < aip->path_goal_dist ) || in_view ) {
787 ai_big_subsys_path_cleanup(aip);
788 } else if ( dist > aip->path_goal_dist ) {
789 // If we have a path to follow, follow it and return
790 if ( aip->path_start != -1 ) {
791 // for now, only follow the path to the first point
792 if ( aip->path_cur < (aip->path_start+aip->path_length-1) ) {
793 if ( aip->goal_objnum != aip->target_objnum ) {
794 //Int3(); // what is going on here? - Get Alan
795 aip->previous_mode = aip->mode;
796 aip->mode = AIM_NONE;
811 // This function is only called from ai_big_chase_attack() when a ship is flying very slowly and
812 // attacking a big ship. The ship should scan for enemy fighter/bombers... if any are close, then
813 // return 1, otherwise return 0;
815 // input: aip => ai_info pointer for Pl_objp
816 // sip => ship_info pointer for Pl_objp
818 // exit: 1 => ship should enter strafe mode
819 // 0 => ship should not change ai mode, no fighter/bomber threats are near
821 // NOTE: uses SCAN_FIGHTERS_INTERVAL and ENTER_STRAFE_THREAT_DIST_SQUARED which are defined in AiBig.h
822 int ai_big_maybe_start_strafe(ai_info *aip, ship_info *sip)
824 // if moving slowly (or stopped), and SIF_SMALL_SHIP, then enter STRAFE mode if enemy fighter/bombers
826 if ( sip->flags & SIF_SMALL_SHIP ) {
827 if ( timestamp_elapsed(aip->scan_for_enemy_timestamp) ) {
833 aip->scan_for_enemy_timestamp = timestamp(SCAN_FIGHTERS_INTERVAL);
834 // iterate through ships, and see if any fighter/bomber from opposite team are near
835 so = GET_FIRST(&Ship_obj_list);
836 while( so != END_OF_LIST(&Ship_obj_list) ) {
837 test_objp = &Objects[so->objnum];
838 test_sp = &Ships[test_objp->instance];
840 if ( test_sp->team != Ships[Pl_objp->instance].team ) {
841 if ( Ship_info[test_sp->ship_info_index].flags & SIF_SMALL_SHIP ) {
842 dist_squared = vm_vec_dist_squared(&Pl_objp->pos, &test_objp->pos);
843 if ( dist_squared < ENTER_STRAFE_THREAT_DIST_SQUARED ) {
852 // If we've reached here, there are no enemy fighter/bombers near
856 // ATTACK submode handler for chase mode.
857 void ai_big_chase_attack(ai_info *aip, ship_info *sip, vector *enemy_pos, float dist_to_enemy)
860 float dot_to_enemy, time_to_hit;
861 polymodel *po = model_get( sip->modelnum );
863 // Maybe evade an incoming weapon.
864 if (((time_to_hit = ai_endangered_by_weapon(aip)) < 4.0f) && (time_to_hit >= 0.0f)) {
865 aip->submode = SM_EVADE_WEAPON;
866 aip->submode_start_time = Missiontime;
867 aip->prev_goal_point = En_objp->pos;
869 // If moving slowly, maybe evade incoming fire.
870 if (Pl_objp->phys_info.speed < 3.0f) {
872 for ( objp = GET_FIRST(&obj_used_list); objp !=END_OF_LIST(&obj_used_list); objp = GET_NEXT(objp) ) {
873 if ((objp->type == OBJ_WEAPON) && (Weapons[objp->instance].team != Ships[Pl_objp->instance].team))
874 if (Weapon_info[objp->instance].subtype == WP_LASER) {
878 vm_vec_sub(&in_vec, &objp->pos, &Pl_objp->pos);
879 if (vm_vec_dot(&in_vec, &objp->orient.fvec) > 0.0f) {
880 dist = vm_vec_normalize(&in_vec);
881 if ((dist < 200.0f) && (vm_vec_dot(&in_vec, &objp->orient.fvec) > 0.95f)) {
882 if ((Objects[objp->parent].signature == objp->parent_sig) && (vm_vec_dist_quick(&objp->pos, &Objects[objp->parent].pos) < 300.0f)) {
883 set_target_objnum(aip, objp->parent);
884 aip->submode = SM_ATTACK;
885 aip->submode_start_time = Missiontime;
887 aip->submode = SM_EVADE;
888 aip->submode_start_time = Missiontime;
889 aip->prev_goal_point = En_objp->pos;
896 // Since ship is moving slowly and attacking a large ship, scan if enemy fighters are near, if so
897 // then enter strafe mode
898 if ( ai_big_maybe_start_strafe(aip, sip) ) {
899 aip->previous_mode = aip->mode;
900 aip->mode = AIM_STRAFE;
901 aip->submode_parm0 = Missiontime; // use parm0 as time strafe mode entered
902 aip->submode = AIS_STRAFE_ATTACK;
903 aip->submode_start_time = Missiontime;
907 } // end if ( Pl_objp->phys_info.speed < 3.0f )
909 // see if Pl_objp needs to reposition to get a good shot at subsystem which is being attacked
910 if ( ai_big_maybe_follow_subsys_path() ) {
914 vector *rel_pos, vec_to_enemy;
915 float weapon_travel_dist;
917 start_bank = Ships[aip->shipnum].weapons.current_primary_bank;
919 if ((po->n_guns) && (start_bank != -1)) {
920 rel_pos = &po->gun_banks[start_bank].pnt[0];
924 dist_to_enemy = vm_vec_normalized_dir(&vec_to_enemy, enemy_pos, &Pl_objp->pos);
925 dot_to_enemy = vm_vec_dot(&vec_to_enemy, &Pl_objp->orient.fvec);
927 vector rvec_vec, *rvec = &rvec_vec;
929 if (dist_to_enemy > 500.0f)
930 compute_desired_rvec(rvec, enemy_pos, &Pl_objp->pos);
934 ai_turn_towards_vector(enemy_pos, Pl_objp, flFrametime, sip->srotation_time, NULL, rel_pos, 0.0f, 0, rvec);
936 // calc range of primary weapon
937 weapon_travel_dist = ai_get_weapon_dist(&Ships[Pl_objp->instance].weapons);
939 if ( aip->targeted_subsys != NULL ) {
940 if (dist_to_enemy > (weapon_travel_dist-20))
941 accelerate_ship(aip, 1.0f);
943 // AL 12-31-97: Move at least as quickly as your target is moving...
944 accelerate_ship(aip, max(1.0f - dot_to_enemy, Objects[aip->target_objnum].phys_info.fspeed/sip->max_speed));
949 if (dot_to_enemy < 0.0f) {
951 } else if (dot_to_enemy < 0.75f) {
954 if (dist_to_enemy > weapon_travel_dist/2.0f) {
957 accel = 1.0f - dot_to_enemy;
961 // use dist normal to enemy here (dont break 50 barrier)
962 if (dist_to_enemy < ATTACK_STOP_DISTANCE) {
963 // accelerate_ship(aip, accel * 0.5f);
964 accelerate_ship(aip, -1.0f);
966 accelerate_ship(aip, accel);
973 // Handler for submode SM_CONTINUOUS_TURN
974 void ai_big_chase_ct()
979 extern void ai_select_secondary_weapon(object *objp, ship_weapon *swp, int priority1 = -1, int priority2 = -1);
980 extern float set_secondary_fire_delay(ai_info *aip, ship *shipp, weapon_info *swip);
981 extern void ai_choose_secondary_weapon(object *objp, ai_info *aip, object *en_objp);
982 extern int maybe_avoid_big_ship(object *objp, object *ignore_objp, ai_info *aip, vector *goal_point, float delta_time);
984 extern void maybe_cheat_fire_synaptic(object *objp, ai_info *aip);
986 // Determine if Pl_objp should fire weapons at current target, based on input parameters
988 // dist_to_enemy => distance (in m) to attack point on current target
989 // dot_to_enemy => dot product between fvec of Pl_objp and vector from Pl_objp to attack point
991 void ai_big_maybe_fire_weapons(float dist_to_enemy, float dot_to_enemy, vector *firing_pos, vector *enemy_pos, vector *enemy_vel)
996 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
997 swp = &Ships[Pl_objp->instance].weapons;
999 if (dot_to_enemy > 0.95f - 0.5f * En_objp->radius/max(1.0f, En_objp->radius + dist_to_enemy)) {
1000 aip->time_enemy_in_range += flFrametime;
1002 // Chance of hitting ship is based on dot product of firing ship's forward vector with vector to ship
1003 // and also the size of the target relative to distance to target.
1004 if (dot_to_enemy > max(0.5f, 0.90f + aip->ai_accuracy/10.0f - En_objp->radius/max(1.0f,dist_to_enemy))) {
1007 temp_shipp = &Ships[Pl_objp->instance];
1008 ship_weapon *tswp = &temp_shipp->weapons;
1010 if ( tswp->num_primary_banks > 0 ) {
1011 Assert(tswp->current_primary_bank < tswp->num_primary_banks);
1012 weapon_info *wip = &Weapon_info[tswp->primary_bank_weapons[tswp->current_primary_bank]];
1014 if (dist_to_enemy < wip->max_speed * wip->lifetime)
1015 ai_fire_primary_weapon(Pl_objp);
1017 int priority1, priority2;
1022 // Maybe favor selecting a bomb.
1023 // Note, if you're firing a bomb, if it's aspect seeking, the firing conditions can be looser.
1024 if (Ship_info[Ships[En_objp->instance].ship_info_index].flags & (SIF_BIG_SHIP | SIF_HUGE_SHIP))
1025 if (En_objp->phys_info.speed * dist_to_enemy < 5000.0f) // Don't select a bomb if enemy moving fast relative to distance
1026 priority1 = WIF_BOMB;
1028 if (!(En_objp->flags & OF_PROTECTED)) {
1029 //ai_select_secondary_weapon(Pl_objp, tswp, priority1, priority2); // Note, need to select to get weapon speed and lifetime
1031 ai_choose_secondary_weapon(Pl_objp, aip, En_objp);
1032 int current_bank = tswp->current_secondary_bank;
1033 weapon_info *swip = &Weapon_info[tswp->secondary_bank_weapons[current_bank]];
1035 // If ship is protected and very low on hits, don't fire missiles.
1036 if ((current_bank > -1) && (!(En_objp->flags & OF_PROTECTED) || (En_objp->hull_strength > 10*swip->damage))) {
1037 if (aip->ai_flags & AIF_UNLOAD_SECONDARIES) {
1038 if (timestamp_until(swp->next_secondary_fire_stamp[current_bank]) > swip->fire_wait*1000.0f) {
1039 swp->next_secondary_fire_stamp[current_bank] = timestamp((int) (swip->fire_wait*1000.0f));
1043 if (timestamp_elapsed(swp->next_secondary_fire_stamp[current_bank])) {
1045 float firing_range = swip->max_speed * swip->lifetime;
1046 // reduce firing range of secondaries in nebula
1047 extern int Nebula_sec_range;
1048 if ((The_mission.flags & MISSION_FLAG_FULLNEB) && Nebula_sec_range) {
1049 firing_range *= 0.8f;
1052 float t = 0.25f; // default delay in seconds until next fire.
1054 if (dist_to_enemy < firing_range*1.0f) {
1057 //vm_vec_scale_add(&future_enemy_pos, enemy_pos, enemy_vel, dist_to_enemy/swip->max_speed);
1058 //if (vm_vec_dist_quick(&future_enemy_pos, firing_pos) < firing_range * 0.8f) {
1059 if (ai_fire_secondary_weapon(Pl_objp)) {
1060 if (aip->ai_flags & AIF_UNLOAD_SECONDARIES) {
1061 t = swip->fire_wait;
1063 t = set_secondary_fire_delay(aip, temp_shipp, swip);
1066 swp->next_secondary_fire_stamp[current_bank] = timestamp((int) (t*1000.0f));
1070 swp->next_secondary_fire_stamp[current_bank] = timestamp((int) (t*1000.0f));
1077 aip->time_enemy_in_range *= (1.0f - flFrametime);
1081 // switch ai ship into chase mode
1082 void ai_big_switch_to_chase_mode(ai_info *aip)
1084 aip->previous_mode = aip->mode;
1085 aip->mode = AIM_CHASE;
1086 aip->submode = SM_ATTACK;
1087 aip->submode_start_time = Missiontime;
1090 extern int ai_big_strafe_maybe_retreat(float dist, vector *target_pos);
1092 // Make object Pl_objp chase object En_objp, which is a big ship, not a small ship.
1095 float dist_to_enemy, dot_to_enemy;
1096 vector player_pos, enemy_pos, vec_to_enemy;
1097 ship_info *sip = &Ship_info[Ships[Pl_objp->instance].ship_info_index];
1098 ship *shipp = &Ships[Pl_objp->instance];
1099 ai_info *aip = &Ai_info[shipp->ai_index];
1100 int enemy_ship_type;
1101 vector predicted_enemy_pos;
1103 Assert(aip->mode == AIM_CHASE);
1105 maybe_cheat_fire_synaptic(Pl_objp, aip);
1107 enemy_ship_type = Ship_info[Ships[En_objp->instance].ship_info_index].flags;
1109 ai_set_positions(Pl_objp, En_objp, aip, &player_pos, &enemy_pos);
1111 player_pos = Pl_objp->pos;
1112 ai_big_pick_attack_point(En_objp, Pl_objp, &enemy_pos, 0.8f);
1114 // Compute the predicted position of the center of the ship, then add the delta to the goal pos.
1115 if (En_objp->phys_info.speed > 3.0f) {
1116 set_predicted_enemy_pos(&predicted_enemy_pos, Pl_objp, En_objp, aip);
1117 vm_vec_add2(&enemy_pos, &predicted_enemy_pos);
1118 vm_vec_sub2(&enemy_pos, &En_objp->pos);
1120 predicted_enemy_pos = En_objp->pos;
1122 if (aip->targeted_subsys != NULL) {
1123 get_subsystem_pos(&enemy_pos, En_objp, aip->targeted_subsys);
1126 dist_to_enemy = vm_vec_normalized_dir(&vec_to_enemy, &enemy_pos, &player_pos); // - En_objp->radius;
1127 dot_to_enemy = vm_vec_dot(&vec_to_enemy, &Pl_objp->orient.fvec);
1129 if (aip->ai_flags & AIF_TARGET_COLLISION) {
1130 if ( ai_big_strafe_maybe_retreat(dist_to_enemy, &enemy_pos) ) {
1131 aip->mode = AIM_STRAFE;
1132 aip->submode = AIS_STRAFE_AVOID;
1133 aip->submode_parm0 = Missiontime; // use parm0 as time strafe mode entered
1138 if (aip->ai_flags & AIF_KAMIKAZE) {
1139 //nprintf(("AI", "Kamikaze: %7.3f %7.3f\n", dot_to_enemy, dist_to_enemy));
1140 accelerate_ship(aip, 1.0f);
1141 if ((dist_to_enemy < 400.0f) && ai_maybe_fire_afterburner(Pl_objp, aip)) {
1142 afterburners_start(Pl_objp);
1143 aip->afterburner_stop_time = Missiontime + 3*F1_0;
1147 // If just acquired target, or target is not in reasonable cone, don't refine believed enemy position.
1148 if ((dot_to_enemy < 0.25f) || (aip->target_time < 1.0f) || (aip->ai_flags & AIF_SEEK_LOCK)) {
1149 update_aspect_lock_information(aip, &vec_to_enemy, dist_to_enemy - En_objp->radius, En_objp->radius);
1150 } else if (aip->targeted_subsys != NULL) {
1151 Assert(aip->targeted_subsys != NULL);
1152 get_subsystem_pos(&enemy_pos, En_objp, aip->targeted_subsys);
1153 vm_vec_add2(&enemy_pos, &predicted_enemy_pos);
1154 vm_vec_sub2(&enemy_pos, &En_objp->pos);
1155 dist_to_enemy = vm_vec_normalized_dir(&vec_to_enemy, &enemy_pos, &player_pos); // - En_objp->radius;
1156 dot_to_enemy = vm_vec_dot(&vec_to_enemy, &Pl_objp->orient.fvec);
1157 update_aspect_lock_information(aip, &vec_to_enemy, dist_to_enemy, En_objp->radius);
1158 } else if (En_objp->flags & OF_PROTECTED) { // If protected and we're not attacking a subsystem, stop attacking!
1159 update_aspect_lock_information(aip, &vec_to_enemy, dist_to_enemy - En_objp->radius, En_objp->radius);
1160 aip->target_objnum = -1;
1161 if (find_enemy(Pl_objp-Objects, MAX_ENEMY_DISTANCE, Skill_level_max_attackers[Game_skill_level]) == -1) {
1162 ai_do_default_behavior(Pl_objp);
1166 update_aspect_lock_information(aip, &vec_to_enemy, dist_to_enemy - En_objp->radius, En_objp->radius);
1169 // If recently acquired target and not looking at target, just turn a bit.
1170 switch (aip->submode) {
1172 case SM_SUPER_ATTACK:
1173 if (vm_vec_dist_quick(&Pl_objp->pos, &predicted_enemy_pos) > 100.0f + En_objp->radius * 2.0f) {
1174 if (maybe_avoid_big_ship(Pl_objp, En_objp, aip, &predicted_enemy_pos, 10.0f))
1178 if (aip->target_time < 2.0f)
1179 if ((dot_to_enemy < 0.9f) || (dist_to_enemy > 300.0f)) {
1180 aip->submode = SM_CONTINUOUS_TURN;
1181 aip->submode_start_time = Missiontime - fl2f(2.75f); // This backdated start time allows immediate switchout.
1182 if (dot_to_enemy > 0.0f)
1183 aip->target_time += flFrametime * dot_to_enemy;
1189 // Set turn and acceleration based on submode.
1191 switch (aip->submode) {
1192 case SM_CONTINUOUS_TURN:
1197 case SM_SUPER_ATTACK:
1198 case SM_ATTACK_FOREVER:
1199 ai_big_chase_attack(aip, sip, &enemy_pos, dist_to_enemy);
1203 ai_big_evade_ship();
1207 ai_big_avoid_ship();
1210 case SM_EVADE_WEAPON:
1215 aip->last_attack_time = Missiontime;
1216 aip->submode = SM_ATTACK;
1220 // maybe Pl_objp was forced into strafe mode, if so return now
1221 if ( aip->mode == AIM_STRAFE )
1224 // Maybe choose a new submode.
1225 if (aip->submode != SM_AVOID && aip->submode != SM_EVADE ) {
1226 // If a very long time since attacked, attack no matter what!
1227 if (aip->submode != SM_SUPER_ATTACK) {
1228 if (Missiontime - aip->last_attack_time > i2f(6)) {
1229 aip->submode = SM_SUPER_ATTACK;
1230 aip->submode_start_time = Missiontime;
1231 aip->last_attack_time = Missiontime;
1235 // If a collision is expected, pull out!
1236 float dist_normal_to_enemy;
1238 if (vm_vec_mag_squared(&aip->big_attack_surface_normal) > 0.9) {
1239 dist_normal_to_enemy = fl_abs((dist_to_enemy * vm_vec_dot(&vec_to_enemy, &aip->big_attack_surface_normal)));
1241 // don;t have normal so use a conservative value here
1242 dist_normal_to_enemy = 0.3f * dist_to_enemy;
1245 // float time_to_enemy = dist_normal_to_enemy / Pl_objp->phys_info.speed * fl_abs(vm_vec_dot(&Pl_objp->phys_info.vel, &aip->big_attack_surface_normal));
1246 // if (Framecount % 30 == 1) {
1247 // mprintf(("normal dist; %.1f, time: %.1f\n", dist_normal_to_enemy, time_to_enemy));
1250 // since we're not in strafe and we may get a bad normal, cap dist_normal_to_enemy as min(0.3*dist_to_enemy, self)
1251 // this will allow us to get closer on a bad normal
1252 dist_normal_to_enemy = max(0.3f*dist_to_enemy, dist_normal_to_enemy);
1254 if (dist_to_enemy < ATTACK_COLLIDE_BASE_DIST) {
1255 // within 50m or 1sec
1256 float time_to_enemy;
1257 if (vm_vec_mag_squared(&aip->big_attack_surface_normal) > 0.9) {
1258 if (Pl_objp->phys_info.speed > 0.1) {
1259 time_to_enemy = dist_normal_to_enemy / fl_abs(vm_vec_dot(&Pl_objp->phys_info.vel, &aip->big_attack_surface_normal));
1262 time_to_enemy = 100.0f;
1265 if (Pl_objp->phys_info.speed > 0.1) {
1266 time_to_enemy = dist_normal_to_enemy / Pl_objp->phys_info.speed;
1269 time_to_enemy = 100.0f;
1273 float speed_dist = max(0.0f, (Pl_objp->phys_info.speed-50) * 2);
1274 if ((dist_normal_to_enemy < ATTACK_COLLIDE_AVOID_DIST + speed_dist) || (time_to_enemy < ATTACK_COLLIDE_AVOID_TIME) ) {
1275 // get away, simulate crsh recovery (don't use avoid)
1276 // accelerate_ship(aip, -1.0f);
1277 big_ship_collide_recover_start(Pl_objp, En_objp, &Pl_objp->pos, NULL);
1278 // aip->submode = SM_AVOID;
1279 // aip->submode_start_time = Missiontime;
1280 } else if ((dist_normal_to_enemy < ATTACK_COLLIDE_SLOW_DIST) || (time_to_enemy < ATTACK_COLLIDE_SLOW_TIME) ) {
1282 accelerate_ship(aip, -1.0f);
1287 if ((dot_to_enemy > 1.0f - 0.1f * En_objp->radius/(dist_to_enemy + 1.0f)) && (Pl_objp->phys_info.speed > dist_to_enemy/5.0f)) {
1288 if (might_collide_with_ship(Pl_objp, En_objp, dot_to_enemy, dist_to_enemy, (aip->targeted_subsys == NULL)*2.0f + 1.5f)) {
1289 if ((Missiontime - aip->last_hit_time > F1_0*4) && (dist_to_enemy < Pl_objp->radius*2 + En_objp->radius*2)) {
1290 accelerate_ship(aip, -1.0f);
1292 aip->submode = SM_AVOID;
1293 aip->submode_start_time = Missiontime;
1299 switch (aip->submode) {
1300 case SM_CONTINUOUS_TURN:
1301 if (Missiontime - aip->submode_start_time > i2f(3)) {
1302 aip->last_attack_time = Missiontime;
1303 aip->submode = SM_ATTACK;
1304 aip->submode_start_time = Missiontime;
1309 case SM_ATTACK_FOREVER:
1313 if (dist_to_enemy > 4*En_objp->radius) {
1314 aip->submode = SM_ATTACK;
1315 aip->submode_start_time = Missiontime;
1316 aip->last_attack_time = Missiontime;
1320 case SM_SUPER_ATTACK:
1324 // if outside box by > 300 m
1325 // DA 4/20/98 can never get here attacking a big ship
1328 float box_dist = get_world_closest_box_point_with_delta(NULL, En_objp, &Pl_objp->pos, &is_inside, 0.0f);
1330 if (box_dist > 300) {
1331 aip->submode = SM_ATTACK;
1332 aip->last_attack_time = Missiontime;
1333 aip->submode_start_time = Missiontime;
1338 /* if (dot_to_enemy > -0.2f) {
1339 aip->submode_start_time = Missiontime;
1340 } else if (Missiontime - aip->submode_start_time > i2f(1)/2) {
1341 if (might_collide_with_ship(Pl_objp, En_objp, dot_to_enemy, dist_to_enemy, 3.0f)) {
1342 aip->submode_start_time = Missiontime;
1344 aip->submode = SM_ATTACK;
1345 aip->last_attack_time = Missiontime;
1346 aip->submode_start_time = Missiontime;
1352 case SM_EVADE_WEAPON:
1353 if (aip->danger_weapon_objnum == -1) {
1354 aip->submode = SM_ATTACK;
1355 aip->submode_start_time = Missiontime;
1356 aip->last_attack_time = Missiontime;
1361 aip->submode = SM_ATTACK;
1362 aip->last_attack_time = Missiontime;
1363 aip->submode_start_time = Missiontime;
1367 // Maybe fire primary weapon and update time_enemy_in_range
1369 //nprintf(("AI", "time_enemy_in_range = %7.3f, dot = %7.3f\n", aip->time_enemy_in_range, dot_to_enemy));
1371 // AL: add condition that Pl_objp must not be following a path to fire. This may be too extreme, but
1372 // I noticed AI ships firing inappropriately when following a path near a big ship.
1373 // TODO: investigate why ships fire (and aren't close to hitting ship) when following a path near
1375 if (aip->mode != AIM_EVADE && aip->path_start == -1 ) {
1376 ai_big_maybe_fire_weapons(dist_to_enemy, dot_to_enemy, &player_pos, &predicted_enemy_pos, &En_objp->phys_info.vel);
1378 aip->time_enemy_in_range *= (1.0f - flFrametime);
1381 void ai_big_ship(object *objp)
1386 // all three parms are output parameters
1387 // Enemy object is En_objp
1388 // pos => world pos of attack point
1389 // dist => distance from Pl_objp front to attack point
1390 // dot => dot of Pl_objp fvec and vector to attack point
1391 // fire_pos => world pos from which firing
1392 void ai_big_attack_get_data(vector *enemy_pos, float *dist_to_enemy, float *dot_to_enemy)
1394 vector player_pos, vec_to_enemy, predicted_enemy_pos;
1395 ship *shipp = &Ships[Pl_objp->instance];
1396 ai_info *aip = &Ai_info[shipp->ai_index];
1397 ship_info *esip = &Ship_info[Ships[En_objp->instance].ship_info_index];
1399 Assert(aip->mode == AIM_STRAFE);
1401 // ensure that Pl_objp is still targeting a big ship
1402 if ( !(esip->flags & (SIF_BIG_SHIP | SIF_HUGE_SHIP)) ) {
1403 ai_big_switch_to_chase_mode(aip);
1407 ai_set_positions(Pl_objp, En_objp, aip, &player_pos, enemy_pos);
1409 player_pos = Pl_objp->pos;
1411 if (aip->targeted_subsys != NULL) {
1412 Assert(aip->targeted_subsys != NULL);
1413 get_subsystem_pos(enemy_pos, En_objp, aip->targeted_subsys);
1415 // checks valid line to target
1416 ai_big_pick_attack_point(En_objp, Pl_objp, enemy_pos, 0.8f);
1419 // Take player pos to be center of ship + ship_radius
1420 vm_vec_scale_add2(&player_pos, &Pl_objp->orient.fvec, Pl_objp->radius);
1422 // If seeking lock, try to point directly at ship, else predict position so lasers can hit it.
1423 // If just acquired target, or target is not in reasonable cone, don't refine believed enemy position.
1424 vm_vec_normalized_dir(&vec_to_enemy, enemy_pos, &player_pos);
1425 *dot_to_enemy=vm_vec_dot(&vec_to_enemy, &Pl_objp->orient.fvec);
1426 if ((*dot_to_enemy < 0.25f) || (aip->target_time < 1.0f) || (aip->ai_flags & AIF_SEEK_LOCK)) {
1427 predicted_enemy_pos=*enemy_pos;
1429 vector gun_pos, pnt;
1430 polymodel *po = model_get( Ship_info[shipp->ship_info_index].modelnum );
1433 // Compute position of gun in absolute space and use that as fire position.
1434 pnt = po->gun_banks[0].pnt[0];
1435 vm_vec_unrotate(&gun_pos, &pnt, &Pl_objp->orient);
1436 vm_vec_add2(&gun_pos, &Pl_objp->pos);
1437 weapon_speed = ai_get_weapon_speed(&shipp->weapons);
1439 set_predicted_enemy_pos_turret(&predicted_enemy_pos, &gun_pos, Pl_objp, enemy_pos, &En_objp->phys_info.vel, weapon_speed, aip->time_enemy_in_range);
1442 *dist_to_enemy = vm_vec_normalized_dir(&vec_to_enemy, &predicted_enemy_pos, &player_pos);
1443 *dot_to_enemy = vm_vec_dot(&vec_to_enemy, &Pl_objp->orient.fvec);
1444 update_aspect_lock_information(aip, &vec_to_enemy, *dist_to_enemy, En_objp->radius);
1446 *enemy_pos = predicted_enemy_pos;
1449 // check to see if Pl_objp has gotten too close to attacking point.. if so, break off by entering
1450 // AIS_STRAFE_RETREAT
1451 int ai_big_strafe_maybe_retreat(float dist, vector *target_pos)
1454 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
1456 vector vec_to_target;
1457 vm_vec_sub(&vec_to_target, target_pos, &Pl_objp->pos);
1459 float dist_to_target, dist_normal_to_target, time_to_target;
1460 dist_to_target = vm_vec_mag_quick(&vec_to_target);
1461 if (vm_vec_mag_quick(&aip->big_attack_surface_normal) > 0.9) {
1462 dist_normal_to_target = -vm_vec_dotprod(&vec_to_target, &aip->big_attack_surface_normal);
1464 dist_normal_to_target = 0.2f * vm_vec_mag_quick(&vec_to_target);
1467 dist_normal_to_target = max(0.2f*dist_to_target, dist_normal_to_target);
1468 time_to_target = dist_normal_to_target / Pl_objp->phys_info.speed;
1470 // add distance penalty for going too fast
1471 float speed_to_dist_penalty = max(0.0f, (Pl_objp->phys_info.speed-50));
1473 //if ((dot_to_enemy > 1.0f - 0.1f * En_objp->radius/(dist_to_enemy + 1.0f)) && (Pl_objp->phys_info.speed > dist_to_enemy/5.0f))
1475 // Inside 2 sec retreat, setting goal point to box point + 300m
1476 // If collision, use std collision resolution.
1477 if ( !(aip->ai_flags & AIF_KAMIKAZE) && ((aip->ai_flags & AIF_TARGET_COLLISION) || (time_to_target < STRAFE_RETREAT_COLLIDE_TIME) || (dist_normal_to_target < STRAFE_RETREAT_COLLIDE_DIST + speed_to_dist_penalty)) ) {
1478 if (aip->ai_flags & AIF_TARGET_COLLISION) {
1479 // use standard collision resolution
1480 aip->ai_flags &= ~AIF_TARGET_COLLISION;
1481 big_ship_collide_recover_start(Pl_objp, En_objp, &Pl_objp->pos, NULL);
1483 // too close for comfort so fly to box point + 300
1484 aip->submode = AIS_STRAFE_RETREAT1;
1485 aip->submode_start_time = Missiontime;
1490 box_dist = get_world_closest_box_point_with_delta(&goal_point, En_objp, &Pl_objp->pos, &is_inside, STRAFE_RETREAT_BOX_DIST);
1493 aip->goal_point = goal_point;
1495 if (ai_maybe_fire_afterburner(Pl_objp, aip)) {
1496 afterburners_start(Pl_objp);
1497 aip->afterburner_stop_time = Missiontime + 3*F1_0;
1507 // attack directly to the turret and fire weapons
1508 void ai_big_strafe_attack()
1513 float target_dist, target_dot, accel, t;
1514 object *target_objp;
1516 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
1518 if ( ai_big_maybe_follow_subsys_path(0) ) {
1522 ai_big_attack_get_data(&target_pos, &target_dist, &target_dot);
1523 if ( ai_big_strafe_maybe_retreat(target_dist, &target_pos) )
1526 target_objp = &Objects[aip->target_objnum];
1528 if (aip->ai_flags & AIF_KAMIKAZE) {
1529 if (target_dist < 1200.0f) {
1530 //nprintf(("AI", "Kamikaze: %7.3f %7.3f\n", target_dot, target_dist));
1531 ai_turn_towards_vector(&target_pos, Pl_objp, flFrametime, Ship_info[Ships[Pl_objp->instance].ship_info_index].srotation_time, NULL, NULL, 0.0f, 0);
1532 accelerate_ship(aip, 1.0f);
1533 if ((target_dist < 400.0f) && ai_maybe_fire_afterburner(Pl_objp, aip)) {
1534 afterburners_start(Pl_objp);
1535 aip->afterburner_stop_time = Missiontime + 3*F1_0;
1541 if (!(aip->ai_flags & AIF_SEEK_LOCK) || (aip->aspect_locked_time < 2.0f)) {
1542 t = ai_endangered_by_weapon(aip);
1543 if ( t > 0.0f && t < 1.5f ) {
1544 // set up goal_point for avoid path to turn towards
1545 aip->goal_point = Pl_objp->pos;
1548 vm_vec_scale_add(&rand_vec, &Pl_objp->orient.fvec, &Pl_objp->orient.uvec, 2.0f);
1551 vm_vec_scale_add(&rand_vec, &Pl_objp->orient.fvec, &Pl_objp->orient.uvec, -2.0f);
1554 vm_vec_scale_add(&rand_vec, &Pl_objp->orient.fvec, &Pl_objp->orient.rvec, 2.0f);
1557 vm_vec_scale_add(&rand_vec, &Pl_objp->orient.fvec, &Pl_objp->orient.rvec, -2.0f);
1561 vm_vec_scale(&rand_vec, 1000.0f);
1562 vm_vec_add2(&aip->goal_point, &rand_vec);
1564 aip->submode = AIS_STRAFE_AVOID;
1565 aip->submode_start_time = Missiontime;
1566 // nprintf(("Alan","Ship %s entering AIS_STRAFE_AVOID at frame %d\n", Ships[aip->shipnum].ship_name, Framecount));
1568 if (ai_maybe_fire_afterburner(Pl_objp, aip)) {
1569 afterburners_start(Pl_objp);
1570 aip->afterburner_stop_time = Missiontime + fl2f(0.5f);
1575 // maybe fire weapons at target
1576 ai_big_maybe_fire_weapons(target_dist, target_dot, &Pl_objp->pos, &En_objp->pos, &En_objp->phys_info.vel);
1577 turn_towards_point(Pl_objp, &target_pos, NULL, 0.0f);
1579 // Slow down if we've not been hit for a while
1580 fix last_hit = Missiontime - aip->last_hit_time;
1581 if ( target_dist > 1200 || last_hit < F1_0*6) {
1585 attack_time = f2fl(Missiontime - aip->submode_start_time);
1586 if ( attack_time > 15 ) {
1588 } else if ( attack_time > 10 ) {
1590 } else if ( attack_time > 8 ) {
1592 } else if ( attack_time > 5 ) {
1600 accelerate_ship(aip, accel);
1602 // if haven't been hit in quite a while, leave strafe mode
1604 long_enough = F1_0*20;
1605 if ( (last_hit > long_enough) && ( (Missiontime - aip->submode_parm0) > long_enough) ) {
1606 ai_big_switch_to_chase_mode(aip);
1610 // pick a new attack point when entering this state, and keep using it
1611 void ai_big_strafe_avoid()
1615 float target_dist, target_dot;
1618 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
1620 mode_time = Missiontime - aip->submode_start_time;
1622 ai_big_attack_get_data(&target_pos, &target_dist, &target_dot);
1623 if ( ai_big_strafe_maybe_retreat(target_dist, &target_pos) )
1626 if ( mode_time > fl2f(0.5)) {
1627 aip->submode = AIS_STRAFE_ATTACK;
1628 aip->submode_start_time = Missiontime;
1629 // nprintf(("Alan","Ship %s entering AIS_STRAFE_ATTACK at frame %d\n", Ships[aip->shipnum].ship_name, Framecount));
1632 turn_towards_point(Pl_objp, &aip->goal_point, NULL, 0.0f);
1633 accelerate_ship(aip, 1.0f);
1636 // move towards aip->goal_point in an evasive manner
1637 void ai_big_strafe_retreat1()
1643 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
1645 dist = vm_vec_dist_quick(&Pl_objp->pos, &aip->goal_point);
1647 aip->submode = AIS_STRAFE_POSITION;
1648 aip->submode_start_time = Missiontime;
1649 // nprintf(("Alan","Ship %s entering AIS_STRAFE_POSITION\n", Ships[aip->shipnum].ship_name));
1653 if (Missiontime - aip->submode_start_time > fl2f(1.50f)) {
1654 // set up goal_point for avoid path to turn towards
1655 aip->prev_goal_point = Pl_objp->pos;
1658 vm_vec_add(&rand_vec, &Pl_objp->orient.fvec, &Pl_objp->orient.uvec);
1661 vm_vec_scale_add(&rand_vec, &Pl_objp->orient.fvec, &Pl_objp->orient.uvec, -1.0f);
1664 vm_vec_add(&rand_vec, &Pl_objp->orient.fvec, &Pl_objp->orient.rvec);
1667 vm_vec_scale_add(&rand_vec, &Pl_objp->orient.fvec, &Pl_objp->orient.rvec, -1.0f);
1671 //vm_vec_scale(&rand_vec, 200.0f);
1672 //vm_vec_add2(&aip->prev_goal_point, &rand_vec);
1673 vm_vec_scale_add(&aip->prev_goal_point, &aip->goal_point, &rand_vec, 200.0f);
1675 aip->submode = AIS_STRAFE_RETREAT2;
1676 aip->submode_start_time = Missiontime;
1679 turn_towards_point(Pl_objp, &aip->goal_point, NULL, 0.0f);
1680 accelerate_ship(aip, 1.0f);
1683 void ai_big_strafe_retreat2()
1688 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
1690 if (Pl_objp->phys_info.flags & PF_AFTERBURNER_ON ) {
1691 if (Missiontime > aip->afterburner_stop_time) {
1692 //nprintf(("AI", "Frame %i, turning off afterburner.\n", AI_FrameCount));
1693 afterburners_stop(Pl_objp);
1697 dist = vm_vec_dist_quick(&Pl_objp->pos, &aip->goal_point);
1699 aip->submode = AIS_STRAFE_POSITION;
1700 aip->submode_start_time = Missiontime;
1701 // nprintf(("Alan","Ship %s entering AIS_STRAFE_POSITION\n", Ships[aip->shipnum].ship_name));
1705 if (Missiontime - aip->submode_start_time > fl2f(0.70f)) {
1706 aip->submode = AIS_STRAFE_RETREAT1;
1707 aip->submode_start_time = Missiontime;
1709 if ( (Missiontime - aip->last_hit_time) < F1_0*5 ) {
1710 if (ai_maybe_fire_afterburner(Pl_objp, aip)) {
1711 afterburners_start(Pl_objp);
1712 aip->afterburner_stop_time = Missiontime + F1_0;
1717 turn_towards_point(Pl_objp, &aip->prev_goal_point, NULL, 0.0f);
1718 accelerate_ship(aip, 1.0f);
1721 // reposition self to begin another strafing run
1722 void ai_big_strafe_position()
1725 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
1726 // TODO: loop around or something!!
1728 aip->submode = AIS_STRAFE_ATTACK;
1729 aip->submode_start_time = Missiontime;
1730 // nprintf(("Alan","Ship %s entering AIS_STRAFE_ATTACK\n", Ships[aip->shipnum].ship_name));
1733 // --------------------------------------------------------------------------
1734 // #define AIS_STRAFE_ATTACK 201 // fly towards target and attack
1735 // #define AIS_STRAFE_AVOID 202 // fly evasive vector to avoid incoming fire
1736 // #define AIS_STRAFE_RETREAT1 203 // fly away from attack point (directly)
1737 // #define AIS_STRAFE_RETREAT1 204 // fly away from attack point (on an avoid vector)
1738 // #define AIS_STRAFE_POSITION 205 // re-position to resume strafing attack
1740 void ai_big_strafe()
1744 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
1746 Assert(aip->mode == AIM_STRAFE);
1749 if ( aip->goal_objnum != aip->target_objnum ) {
1750 Int3(); // what is going on here? - Get Alan
1751 aip->mode = AIM_NONE;
1756 // check if target is still a big ship... if not enter chase mode
1757 if ( !(Ship_info[Ships[En_objp->instance].ship_info_index].flags & (SIF_BIG_SHIP|SIF_HUGE_SHIP)) ) {
1758 ai_big_switch_to_chase_mode(aip);
1762 switch (aip->submode) {
1763 case AIS_STRAFE_ATTACK:
1764 ai_big_strafe_attack();
1766 case AIS_STRAFE_AVOID:
1767 ai_big_strafe_avoid();
1769 case AIS_STRAFE_RETREAT1:
1770 ai_big_strafe_retreat1();
1772 case AIS_STRAFE_RETREAT2:
1773 ai_big_strafe_retreat2();
1775 case AIS_STRAFE_POSITION:
1776 ai_big_strafe_position();
1780 Int3(); // Illegal submode for AIM_STRAFE
1785 // See if Pl_objp should enter strafe mode (This is called from maybe_evade_dumbfire_weapon(), and the
1786 // weapon_objnum is for a weapon that is about to collide with Pl_objp
1788 // Check if weapon_objnum was fired by Pl_objp's target, and whether Pl_objp's target is a big ship, if
1789 // so, enter AIM_STRAFE
1790 int ai_big_maybe_enter_strafe_mode(object *pl_objp, int weapon_objnum, int consider_target_only)
1794 object *weapon_objp, *parent_objp;
1796 aip = &Ai_info[Ships[pl_objp->instance].ai_index];
1797 Assert(aip->mode != AIM_STRAFE); // can't happen
1799 // if Pl_objp has no target, then we can't enter strafe mode
1800 if ( aip->target_objnum < 0 ) {
1804 // if target is not a ship, stafe mode is not possible
1805 if ( Objects[aip->target_objnum].type != OBJ_SHIP ) {
1809 sip = &Ship_info[Ships[Objects[aip->target_objnum].instance].ship_info_index];
1811 // if Pl_objp's target is not a big/capital ship, then cannot enter strafe mode
1812 // AL 12-31-97: Even though transports are considered big ships, don't enter strafe mode on them
1813 if ( !(sip->flags & (SIF_BIG_SHIP | SIF_HUGE_SHIP)) || (sip->flags & SIF_TRANSPORT) ) {
1817 // If Pl_objp not a fighter or bomber, don't enter strafe mode. -- MK, 11/11/97.
1818 if ( !(Ship_info[Ships[pl_objp->instance].ship_info_index].flags & (SIF_FIGHTER | SIF_BOMBER)) ) {
1822 Assert(weapon_objnum >= 0 && weapon_objnum < MAX_OBJECTS);
1823 weapon_objp = &Objects[weapon_objnum];
1824 Assert(weapon_objp->type == OBJ_WEAPON);
1826 Assert(weapon_objp->parent >= 0 && weapon_objp->parent < MAX_OBJECTS);
1827 parent_objp = &Objects[weapon_objp->parent];
1828 if ( (parent_objp->signature != weapon_objp->parent_sig) || (parent_objp->type != OBJ_SHIP) ) {
1832 // Maybe the ship which fired the weapon isn't the current target
1833 if ( OBJ_INDEX(parent_objp) != aip->target_objnum ) {
1835 //JAS IMPOSSIBLE if (1) { // consider_target_only ) {
1836 //JAS IMPOSSIBLE return 0;
1837 //JAS IMPOSSIBLE } else {
1839 sip = &Ship_info[Ships[parent_objp->instance].ship_info_index];
1840 if ( !(sip->flags & (SIF_BIG_SHIP | SIF_HUGE_SHIP)) || (sip->flags & SIF_TRANSPORT) ) {
1843 set_target_objnum(aip, OBJ_INDEX(parent_objp));
1847 ai_big_strafe_maybe_attack_turret(pl_objp, weapon_objp);
1849 // if we've got this far, the weapon must have come from the player's target, and it is a
1850 // big/capital ship... so enter strafe mode
1851 aip->previous_mode = aip->mode;
1852 aip->mode = AIM_STRAFE;
1853 aip->submode_parm0 = Missiontime; // use parm0 as time strafe mode entered
1854 aip->submode = AIS_STRAFE_AVOID;
1855 aip->submode_start_time = Missiontime;
1856 // nprintf(("Alan","%s Accepted strafe mode\n", Ships[pl_objp->instance].ship_name));
1861 // Consider attacking a turret, if a turret actually fired the weapon
1862 // input: ship_objp => ship that will attack the turret
1864 void ai_big_strafe_maybe_attack_turret(object *ship_objp, object *weapon_objp)
1867 object *parent_objp;
1869 Assert(ship_objp->type == OBJ_SHIP);
1870 aip = &Ai_info[Ships[ship_objp->instance].ai_index];
1872 // Make decision to attack turret based on AI class. The better AI ships will realize that
1873 // it is better to take out the turrets first on a big ship.
1874 if ( (frand()*100) > (aip->ai_courage-15) )
1877 // If ship is already attacking a subsystem, don't switch
1878 if ( aip->targeted_subsys != NULL ) {
1882 // If the weapon is not from a turret, return
1883 if ( Weapons[weapon_objp->instance].turret_subsys == NULL ) {
1887 // Only attack turret if it sits on current target
1888 Assert(weapon_objp->parent >= 0 && weapon_objp->parent < MAX_OBJECTS);
1889 parent_objp = &Objects[weapon_objp->parent];
1890 if ( (parent_objp->signature != weapon_objp->parent_sig) || (parent_objp->type != OBJ_SHIP) ) {
1894 if ( aip->target_objnum != OBJ_INDEX(parent_objp) ) {
1898 // attack the turret
1899 set_targeted_subsys(aip, Weapons[weapon_objp->instance].turret_subsys, OBJ_INDEX(parent_objp));