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/Ship/AiBig.cpp $
15 * C module for AI code related to large ships
18 * Revision 1.5 2002/06/17 06:33:10 relnev
19 * ryan's struct patch for gcc 2.95
21 * Revision 1.4 2002/06/09 04:41:26 relnev
22 * added copyright header
24 * Revision 1.3 2002/06/01 07:12:33 relnev
25 * a few NDEBUG updates.
27 * removed a few warnings.
29 * Revision 1.2 2002/05/07 03:16:51 theoddone33
30 * The Great Newline Fix
32 * Revision 1.1.1.1 2002/05/03 03:28:10 root
36 * 13 8/31/99 4:24p Andsager
37 * Reduce collisions when attacking big ships.
39 * 12 7/19/99 2:18p Mikeb
42 * 11 7/19/99 2:11p Mikeb
43 * DA: sometimes big_ship_attack_normal is not known
45 * 10 6/14/99 3:21p Andsager
46 * Allow collisions between ship and its debris. Fix up collision pairs
47 * when large ship is warping out.
49 * 9 6/02/99 5:41p Andsager
50 * Reduce range of secondary weapons not fired from turrets in nebula.
51 * Reduce range of beams fired from turrrets in nebula
53 * 8 5/13/99 2:31p Jamesa
54 * DA: Temp fix when attacking subsys of big ship and BS is blown up.
56 * 7 5/06/99 11:46a Andsager
57 * Bug fixes. Don't get into illegal strafe submode. Don't choose turret
58 * enemy objnum for beam protected.
60 * 6 4/23/99 12:01p Johnson
63 * 5 4/20/99 3:40p Andsager
64 * Changes to big ship ai. Uses bounding box as limit where to fly to
67 * 4 4/16/99 5:54p Dave
68 * Support for on/off style "stream" weapons. Real early support for
69 * target-painting lasers.
71 * 3 10/13/98 9:29a Dave
72 * Started neatening up freespace.h. Many variables renamed and
73 * reorganized. Added AlphaColors.[h,cpp]
75 * 2 10/07/98 10:53a Dave
78 * 1 10/07/98 10:51a Dave
80 * 77 5/25/98 12:12a Mike
81 * Improve big ship avoidance to avoid big ships when in a nearby dock
82 * mode. Fixes very dumb looking behavior in sm2-01a. Verified sm1-08a
83 * not too dumb at start.
85 * 76 5/23/98 2:38a Mike
86 * Improve balance of cheat-firing Synaptics.
88 * 75 5/23/98 12:40a Mike
89 * Hook for Delta wing to fire Synaptic bombs in sm3-09a.
91 * 74 5/22/98 12:08p Mike
92 * Force reset of aspect locking when AI ships switch banks due to
93 * good-time-to-unload-secondaries
95 * 73 5/21/98 1:25p Lawrance
96 * Fix exception in ai_bpap() when no verts are in closest octant
98 * 72 5/21/98 9:57a Mike
99 * Massively improve firing of bombs at big ships. Improve willingness to
100 * take incoming fire to deliver bomb. Make a little easier to gain
103 * 71 5/12/98 10:06a Mike
104 * Fix a jillion bugs preventing ships from firing bombs at Lucifer in
107 * 70 5/10/98 11:30p Mike
108 * Better firing of bombs, less likely to go into strafe mode.
110 * 69 5/10/98 3:41a Lawrance
111 * Fix bug that was preventing ships from leaving strafe mode
113 * 68 5/08/98 4:39p Mike
114 * Make ships match bank when attacking large ships.
116 * 67 5/07/98 11:59p Mike
117 * Remove unneeded code, computation of num_verts.
119 * 66 4/29/98 5:01p Mike
120 * Large overhaul in how turrets fire.
122 * 65 4/27/98 11:59p Mike
123 * Intermediate checkin. Getting big ship turrets firing at big ships to
124 * use pick_big_attack_point.
126 * 64 4/23/98 12:32a Mike
127 * Fix bogus math which looked at (1-fov) instead of fov.
129 * 63 4/13/98 4:52p Allender
130 * remove AI_frametime and us flFrametime instead. Make lock warning work
131 * in multiplayer for aspect seeking missiles. Debris fixups
133 * 62 4/13/98 3:27p Lawrance
134 * Fix bug that caused ships to leave strafe mode right away since they
135 * hadn't taken damage for a while
137 * 61 4/12/98 2:02p Mike
138 * Make small ships avoid big ships.
139 * Turn on Collide_friendly flag.
141 * 60 4/01/98 9:21p John
142 * Made NDEBUG, optimized build with no warnings or errors.
144 * 59 3/25/98 12:00a Allender
145 * MK: make sure that output from function gets a valid valud (ai_pbap I
148 * 58 3/24/98 10:07p Adam
149 * AL: Add another SDL_assert() to try and catch bogus wp->big_attack_point
151 * 57 3/24/98 9:56p Adam
152 * AL: SDL_assert that local_attack_point is valid in ai_bpap
154 * 56 3/21/98 3:36p Mike
155 * Fix/optimize attacking of big ships.
157 * 55 3/16/98 5:17p Mike
158 * Make ships not get stuck on big ships when attacking.
160 * 54 3/16/98 12:03a Mike
161 * Add support for kamikaze mode. Add AIF_NO_DYNAMIC which means
162 * relentlessly pursue current goal.
164 * 53 3/12/98 4:04p Lawrance
165 * Leave strafe mode if haven't been hit for a while and no enemy
166 * fighter/bombers are close by.
168 * 52 3/09/98 5:12p Mike
169 * Make sure Pl_objp uses are valid.
170 * Throw asteroids at ships in asteroid field, not "Gal"
171 * Support ships warp out if no goals after 30 seconds.
173 * 51 3/03/98 11:51p Lawrance
174 * Ensure target is a ship before looking at SIF flags
176 * 50 3/02/98 11:35a Mike
177 * Fix logic with ai_do_default_behavior -- return after call.
179 * 49 2/19/98 7:37p Lawrance
180 * Fix bug that was causing problems with subsystem path following.
182 * 48 2/14/98 3:38p Mike
183 * Make bombs have arm time, drop for 1/2 second, have hull_strength.
184 * Make them not fired until closer to target.
186 * 47 2/13/98 3:56p Mike
187 * Make ships more likely to stick to player orders, not get so distracted
188 * by getting hit by someone else.
190 * 46 2/11/98 4:30p Lawrance
191 * Improve disarm/disable behavior.
193 * 45 2/11/98 1:16a Mike
194 * Mods to AI behavior to make it harder to stay on a ship's tail. Not
195 * too much improvement.
197 * 44 2/05/98 12:51a Mike
198 * Early asteroid stuff.
200 * 43 1/30/98 11:28a Comet
201 * Fix indexing problem into verts in ai_bpap()
203 * 42 1/29/98 10:46p Mike
204 * In ai_big_pick_attack_point, handle case of octant with no points.
206 * 41 1/29/98 1:39p Mike
207 * Better heat seeking homing on big ships.
209 * 40 1/27/98 4:18p Mike
210 * Not fire weapons too early when attacking large ships. Aspect lock
211 * take proper amount of time for AI ships.
213 * 39 1/22/98 5:14p Lawrance
214 * clean up ai_big code, clear path info when stop attacking a subsystem
216 * 38 1/20/98 11:41p Mike
217 * Ships use new system of preferred big weapons to fire. Also, support
218 * AIF_UNLOAD_SECONDARIES which means fire as fast as possible.
220 * 37 1/20/98 9:47a Mike
221 * Suppress optimized compiler warnings.
222 * Some secondary weapon work.
224 * 36 1/17/98 4:45p Mike
225 * Better support for AI selection of secondary weapons.
227 * 35 1/16/98 3:57p Mike
228 * Clean up some bugs with attacking of protected ships. Make turrets
229 * only fire at targets that are within range.
231 * 34 1/16/98 11:32a Mike
232 * Fix bug when a ship is attacking a dead subsystem on a protected ship.
234 * 33 1/07/98 1:32p Lawrance
235 * Remove some nprintf output
237 * 32 1/07/98 1:21p Sandeep
238 * Fix bug where accessing uninited pointer
240 * 31 1/06/98 6:58p Lawrance
241 * Attack turrets (sometimes) when fired upon while attacking a ship.
243 * 30 12/31/97 6:28p Lawrance
244 * Improve attacking subsystems on moving ships.
246 * 29 12/31/97 4:16p Lawrance
247 * Use different fov's for attacking subsystems depending if ship is
250 * 28 12/31/97 4:05p Mike
251 * Support for all teams optionally attacking all teams.
252 * Lead big ships when attacking their hull.
254 * 27 12/31/97 12:26p Lawrance
255 * Don't enter strafe mode for transports, fix bug that prevented strafe
256 * mode from getting entered.
258 * 26 12/30/97 5:20p Mike
259 * Don't fire secondaries at a protected ship if its hull is very weak.
261 * 25 12/30/97 4:26p Lawrance
262 * Take out some debug statements
264 * 24 12/15/97 7:16p Lawrance
265 * improving subsystem attacking
267 * 23 12/02/97 11:58a Lawrance
268 * avoid during strafe mode only when endangered by a weapon
270 * 22 12/01/97 5:11p Lawrance
271 * make strafe mode more effective... slow down when approaching and use
272 * afterburner in avoids
274 * 21 11/27/97 4:21p Lawrance
275 * set submode to -1 when switching to AIM_NONE from AIM_STRAFE
277 * 20 11/24/97 2:27a Lawrance
278 * if attacking a big ship and moving very slow, enter strafe mode if
279 * enemy fighter/bombers are close by
281 * 19 11/14/97 11:27a Johnson
282 * if goal_objnum is -1, and in STRAFE, return 1 from
283 * ai_maybe_follow_subsys_path(), so break out of STRAFE code
285 * 18 11/13/97 11:51a Johnson
286 * ALAN: comment out Int3() in AiBig... need to test on my own machine
288 * 17 11/12/97 11:51p Lawrance
289 * only check target_objnum == goal_objnum when following path
291 * 16 11/12/97 11:01p Lawrance
292 * change call to ai_find_path()
293 * ensure goal_objnum == target_objnum in STRAFE
295 * 15 11/12/97 11:18a Lawrance
296 * fix bug in path following of subsystems
298 * 14 11/11/97 5:22p Mike
299 * Don't allow ships to attack navbuoys.
300 * Make ships lead big ships with dumbfire.
301 * Make ships smarter about leaving evade weapon mode.
302 * Fix a couple SDL_assert() bugs.
304 * 13 11/06/97 6:27p Lawrance
305 * fix bug that was messing up retreat point in STRAFE mode
307 * 12 11/06/97 4:53p Mike
308 * Limit number of ships that can simultaneously attack another. Make
309 * turrets inherit AI class from parent ship.
311 * 11 11/06/97 12:27a Mike
312 * Better avoid behavior.
313 * Modify ai_turn_towards_vector() to take a flag parameter.
315 * 10 11/02/97 10:55p Lawrance
316 * removed some unused code, added some comments
318 * 9 11/01/97 4:01p Mike
319 * Adapt to new ai_find_path().
321 * 8 10/31/97 11:24a Lawrance
322 * If taget changes from a big ship to small ship while in AIM_STRAFE,
323 * switch to AIM_CHASE
325 * 7 10/30/97 10:06p Lawrance
326 * chg some timing values so ship will reach retreat point
328 * 6 10/30/97 9:17p Lawrance
329 * work on getting AIM_STRAFE working well with disable/disarm, try to
332 * 5 10/30/97 12:32a Lawrance
333 * further work on AIM_STRAFE
335 * 4 10/29/97 6:25p Lawrance
336 * add AIM_STRAFE functionality
338 * 3 10/26/97 4:19p Lawrance
339 * added ai_get_weapon_dist()
341 * 2 10/26/97 3:24p Lawrance
342 * split off large ship ai code into AiBig.cpp
349 #include "linklist.h"
359 #include "floating.h"
361 #include "freespace.h"
363 #include "missiongoals.h"
364 #include "missionlog.h"
369 #include "hudmessage.h"
370 #include "missionmessage.h"
371 #include "cmeasure.h"
372 #include "staticrand.h"
373 #include "multimsgs.h"
374 #include "afterburner.h"
378 #include "missionparse.h"
381 #pragma optimize("", off)
382 #pragma auto_inline(off)
385 #define SCAN_FIGHTERS_INTERVAL 2000 // how often an AI fighter/bomber should scan for enemy fighter/bombers
386 // if sitting still and pounding on a big ship. If enemy fighters are
387 // close ( < ENTER_STRAFE_THREAT_DIST ), then enter AIM_STRAFE
389 #define ENTER_STRAFE_THREAT_DIST_SQUARED 360000 // use squared distance, instead of 600
391 #define MIN_DOT_TO_ATTACK_SUBSYS 0.7f
392 #define MIN_DOT_TO_ATTACK_MOVING_SUBSYS 0.97f
394 // AI BIG MAGIC NUMBERS
395 #define STRAFE_RETREAT_COLLIDE_TIME 2.0 // when anticipated collision time is less than this, begin retreat
396 #define STRAFE_RETREAT_COLLIDE_DIST 100 // when perpendicular distance to *surface* is less than this, begin retreat
397 #define STRAFE_RETREAT_BOX_DIST 300 // distance beyond the bounding box to retreat
399 #define EVADE_BOX_BASE_DISTANCE 300 // standard distance to end evade submode
400 #define EVADE_BOX_MIN_DISTANCE 200 // minimun distance to end evade submode, after long time
402 #define ATTACK_STOP_DISTANCE 150 // when distance to target is less than this, put on brakes
404 #define ATTACK_COLLIDE_BASE_DIST 300 // absolute distance at which to begin checking for possible collision
405 #define ATTACK_COLLIDE_AVOID_DIST 60 // perpendicular distance to attack surface at which begin avoiding
406 #define ATTACK_COLLIDE_AVOID_TIME 1.0 // anticipated collision time at which to begin evade
407 #define ATTACK_COLLIDE_SLOW_DIST 150 // perpendicular distance to attack surface at which begin slowing down
408 #define ATTACK_COLLIDE_SLOW_TIME 1.5 // anticipated collision time at which to begin slowing down
411 // forward declarations
412 void ai_big_evade_ship();
413 void ai_big_chase_attack(ai_info *aip, ship_info *sip, vector *enemy_pos, float dist_to_enemy);
414 void ai_big_avoid_ship();
415 int ai_big_maybe_follow_subsys_path(int do_dot_check=1);
417 extern int model_which_octant_distant_many( vector *pnt, int model_num,matrix *model_orient, vector * model_pos, polymodel **pm, int *octs);
418 extern void compute_desired_rvec(vector *rvec, vector *goal_pos, vector *cur_pos);
419 extern void big_ship_collide_recover_start(object *objp, object *big_objp, vector *collide_pos, vector *collision_normal);
422 // Called by ai_big_pick_attack_point.
423 // Generates a random attack point.
424 // If truly_random flag set (haha), then generate a pretty random number. Otherwise, generate a static rand which
425 // tends to not change from frame to frame.
426 // Try four times and choose nearest point to increase chance of getting a good point.
427 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)
430 vector result_point, best_point;
437 best_point = objp->pos;
438 nearest_dist = weapon_travel_dist;
440 model_which_octant_distant_many(attacker_objp_pos, Ships[objp->instance].modelnum, &objp->orient, &objp->pos, &pm, octs);
442 num_tries = (int) (vm_vec_dist(&objp->pos, attacker_objp_pos)/objp->radius);
447 num_tries = 4 - num_tries;
449 // Index #0 is best one.
450 if ( pm->octants[octs[0]].verts ) {
451 *local_attack_point = *pm->octants[octs[0]].verts[0]; // Set just in case it doesn't get set below.
453 vm_vec_zero(local_attack_point);
456 for (q=0; q<4; q++) {
457 octp = &pm->octants[octs[q]];
458 if (octp->nverts > 0) {
460 if (num_tries > octp->nverts)
461 num_tries = octp->nverts;
463 if (num_tries > octp->nverts)
464 num_tries = octp->nverts;
466 for (i=0; i<num_tries; i++) {
471 index = (int) (frand() * (octp->nverts));
473 rel_point = *octp->verts[index];
474 vm_vec_unrotate(&result_point, &rel_point, &objp->orient);
475 vm_vec_add2(&result_point, &objp->pos);
477 dist = vm_vec_normalized_dir(&v2p, &result_point, attacker_objp_pos);
478 dot = vm_vec_dot(&v2p, attacker_objp_fvec);
481 if (dist < nearest_dist) {
483 best_point = result_point;
484 *local_attack_point = rel_point;
485 SDL_assert( !vm_is_vec_nan(local_attack_point) );
486 if (dot > (1.0f + fov)/2.0f) // If this point is quite good, quit searching for a better one.
495 *attack_point = best_point;
497 // Cast from attack_objp_pos to local_attack_pos and check for nearest collision.
498 // If no collision, cast to (0,0,0) [center of big ship]** [best_point initialized to 000]
500 // do in world coords to get attack point, then translate to local for local_attack_point
501 vector attack_dir, end_point, temp;
503 dist = vm_vec_normalized_dir(&attack_dir, attack_point, attacker_objp_pos);
506 vm_vec_scale_add(&end_point, attack_point, &attack_dir, 30.0f);
508 vm_vec_scale_add(&end_point, attack_point, attacker_objp_fvec, 30.0f);
512 mc.model_num = Ships[objp->instance].modelnum;
513 mc.orient = &objp->orient;
515 mc.p0 = attacker_objp_pos;
517 mc.flags = MC_CHECK_MODEL;
521 if (mc.num_hits > 0) {
522 *attack_point = mc.hit_point_world;
523 vm_vec_sub(&temp, attack_point, &objp->pos);
524 vm_vec_rotate(local_attack_point, &temp, &objp->orient);
525 if (surface_normal) {
526 vm_vec_unrotate(surface_normal, &mc.hit_normal, &objp->orient);
529 vm_vec_zero(local_attack_point);
530 *attack_point = objp->pos;
531 if (surface_normal) {
532 vm_vec_zero(surface_normal);
537 // Stuff a point to attack based on nearest octant.
538 // If no points in that octant, leave attack_point unmodified.
540 // Note: Default value for fov is 1.0f 1.0f means don't use fov parameter.
541 // If fov != 1.0f, try up to four times to find a point that's in the field of view.
542 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)
544 if (!timestamp_elapsed(ssp->turret_pick_big_attack_point_timestamp)) {
546 vm_vec_unrotate(&result_point, &ssp->turret_big_attack_point, &objp->orient);
547 vm_vec_add(attack_point, &result_point, &objp->pos);
549 vector local_attack_point;
550 ssp->turret_pick_big_attack_point_timestamp = timestamp(2000 + (int) (frand()*500.0f));
551 ai_bpap(objp, gpos, gvec, attack_point, &local_attack_point, fov, weapon_travel_dist, NULL);
552 ssp->turret_big_attack_point = local_attack_point;
556 // Stuff a point to attack based on nearest octant.
557 // If no points in that octant, leave attack_point unmodified.
559 // Note: Default value for fov is 1.0f 1.0f means don't use fov parameter.
560 // If fov != 1.0f, try up to four times to find a point that's in the field of view.
561 // Note, attacker_objp can be a ship or a weapon.
562 void ai_big_pick_attack_point(object *objp, object *attacker_objp, vector *attack_point, float fov)
564 SDL_assert(objp->instance > -1);
565 SDL_assert(objp->type == OBJ_SHIP);
567 vector local_attack_point;
569 switch (attacker_objp->type) {
571 ai_info *attacker_aip;
572 attacker_aip = &Ai_info[Ships[attacker_objp->instance].ai_index];
573 if (!timestamp_elapsed(attacker_aip->pick_big_attack_point_timestamp)) {
576 vm_vec_unrotate(&result_point, &attacker_aip->big_attack_point, &objp->orient);
577 vm_vec_add(attack_point, &result_point, &objp->pos);
582 attacker_aip->pick_big_attack_point_timestamp = timestamp(2000 + (int) (frand()*500.0f));
586 weapon *wp = &Weapons[attacker_objp->instance];
588 if (!timestamp_elapsed(wp->pick_big_attack_point_timestamp)) {
591 vm_vec_unrotate(&result_point, &wp->big_attack_point, &objp->orient);
592 vm_vec_add(attack_point, &result_point, &objp->pos);
596 wp->pick_big_attack_point_timestamp = timestamp(2000 + (int) (frand()*500.0f));
602 // checks valid line to target
603 vector surface_normal;
604 ai_bpap(objp, &attacker_objp->pos, &attacker_objp->orient.v.fvec, attack_point, &local_attack_point, fov, 99999.9f, &surface_normal);
606 switch (attacker_objp->type) {
608 ai_info *attacker_aip;
609 // if we can't find a new local_attack_point don't change local_attack_point
610 if (vm_vec_mag_squared(&local_attack_point) < 1) {
614 attacker_aip = &Ai_info[Ships[attacker_objp->instance].ai_index];
615 attacker_aip->big_attack_point = local_attack_point;
616 attacker_aip->big_attack_surface_normal = surface_normal;
620 weapon *wp = &Weapons[attacker_objp->instance];
621 wp->big_attack_point = local_attack_point;
622 SDL_assert( !vm_is_vec_nan(&wp->big_attack_point) );
630 // Handler for SM_EVADE submode ( called from ai_big_chase() )
631 void ai_big_evade_ship()
633 vector player_pos, enemy_pos;
635 ship *shipp = &Ships[Pl_objp->instance];
636 ai_info *aip = &Ai_info[shipp->ai_index];
637 vector randvec, semi_enemy_pos;
639 ai_set_positions(Pl_objp, En_objp, aip, &player_pos, &enemy_pos);
641 dist = vm_vec_dist_quick(&player_pos, &enemy_pos);
642 vm_vec_rand_vec_quick(&randvec);
643 if ((Missiontime>>14) & 1) {
644 vm_vec_scale_add(&semi_enemy_pos, &enemy_pos, &randvec, dist/2.0f);
645 aip->prev_goal_point = semi_enemy_pos;
647 semi_enemy_pos = aip->prev_goal_point;
650 accelerate_ship(aip, 1.0f - ((Missiontime>>8) & 0x3f)/128.0f );
651 turn_away_from_point(Pl_objp, &semi_enemy_pos, 0.0f);
656 box_dist = get_world_closest_box_point_with_delta(&box_vec, En_objp, &player_pos, &is_inside, EVADE_BOX_BASE_DISTANCE);
657 if (box_dist > EVADE_BOX_BASE_DISTANCE) {
658 aip->submode = SM_ATTACK;
659 aip->submode_start_time = Missiontime;
660 } else if ((box_dist > EVADE_BOX_MIN_DISTANCE) && (Missiontime - aip->submode_start_time > i2f(5)) ) {
661 aip->submode = SM_ATTACK;
662 aip->submode_start_time = Missiontime;
667 /* if (dist > 4*En_objp->radius) {
668 aip->submode = SM_ATTACK;
669 aip->submode_start_time = Missiontime;
670 } else if (dist > En_objp->radius) {
671 if (Missiontime - aip->submode_start_time > i2f(5)) {
672 aip->submode = SM_ATTACK;
673 aip->submode_start_time = Missiontime;
678 // Handler for SM_AVOID submode ( called from ai_big_chase() )
679 void ai_big_avoid_ship()
684 // reset path following information
685 void ai_big_subsys_path_cleanup(ai_info *aip)
687 if ( aip->ai_flags & AIF_ON_SUBSYS_PATH ) {
688 aip->ai_flags &= ~AIF_ON_SUBSYS_PATH;
689 aip->path_goal_dist = -1;
690 aip->path_start = -1;
692 aip->path_length = 0;
696 // Maybe Pl_objp needs to follow a path to get in line-of-sight to a subsystem
697 // input: do_dot_check => default value 0, flag to indicate whether check should be done to ensure
698 // subsystem is within certain field of view. We don't want to check fov when
699 // strafing, since ship is weaving to avoid turret fire
700 int ai_big_maybe_follow_subsys_path(int do_dot_check)
703 float dot = 1.0f, min_dot;
706 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
707 target_objp = &Objects[aip->target_objnum];
709 if ( (aip->targeted_subsys != NULL) && (aip->target_objnum >= 0) && (aip->targeted_subsys->system_info->path_num >= 0) ) {
711 int subsys_path_num, subsys_in_sight, checked_sight;
714 pm = model_get( Ships[Pl_objp->instance].modelnum );
716 // If attacking a subsystem, ensure that we have an unobstructed line of sight... if not, then move
717 // towards path linked to subsystem
718 subsys_in_sight = 0; // assume Pl_objp doesn't have line of sight to subys
720 // only check for subsystem sight every N milliseconds
722 if ( timestamp_elapsed(aip->path_subsystem_next_check) ) {
723 vector geye, gsubpos;
726 aip->path_subsystem_next_check = timestamp(1500);
728 // get world pos of eye (stored in geye)
729 ep = &(pm->view_positions[0] );
730 model_find_world_point( &geye, &ep->pnt, Ships[Pl_objp->instance].modelnum, 0, &Pl_objp->orient, &Pl_objp->pos );
732 // get world pos of subsystem
733 vm_vec_unrotate(&gsubpos, &aip->targeted_subsys->system_info->pnt, &En_objp->orient);
734 vm_vec_add2(&gsubpos, &En_objp->pos);
738 // Calc dot between subsys normal (based on using path info), and subsys_to_eye vector. This is
739 // useful later when we want to decide whether we have a realistic line-of-sight to the subsystem.
740 vector subsys_normal, subsys_to_eye;
741 if ( do_dot_check ) {
742 if ( !ship_return_subsys_path_normal(&Ships[target_objp->instance], aip->targeted_subsys, &gsubpos, &subsys_normal) ) {
743 vm_vec_normalized_dir(&subsys_to_eye, &geye, &gsubpos);
744 dot = vm_vec_dot(&subsys_normal, &subsys_to_eye);
748 if ( ship_subsystem_in_sight(En_objp, aip->targeted_subsys, &geye, &gsubpos, 1) ) {
753 // check if subsystem not in sight
754 min_dot = (target_objp->phys_info.fspeed > 5.0f?MIN_DOT_TO_ATTACK_MOVING_SUBSYS:MIN_DOT_TO_ATTACK_SUBSYS);
755 if ( (checked_sight && ((!subsys_in_sight) || (dot < min_dot)) ) ) {
757 aip->path_goal_dist = 5;
758 subsys_path_num = aip->targeted_subsys->system_info->path_num;
759 if ( (aip->path_start) == -1 || (aip->mp_index != subsys_path_num) ) {
760 // maybe create a new path
761 if ( subsys_path_num >= 0 ) {
762 SDL_assert(aip->target_objnum >= 0);
763 ai_find_path(Pl_objp, aip->target_objnum, subsys_path_num, 0, 1);
764 if ( aip->path_start >= 0 ) {
765 aip->ai_flags |= AIF_ON_SUBSYS_PATH;
771 if ( checked_sight && subsys_in_sight && (dot > min_dot) ) {
772 // we've got a clear shot, stay here for a bit
773 aip->path_subsystem_next_check = timestamp_rand(5000,8000);
776 // If there is a path that we are tracking, see if ship has gotten to within
777 // aip->path_goal_dist units. If so, then ship can stop following the path. This
778 // is required since we don't want to follow the path all the way to the subsystem,
779 // and we want ships to stop different distances from their path destination
780 if ( aip->path_length > 0 ) {
784 SDL_assert(aip->path_length >= 2);
785 dist = vm_vec_dist_quick(&Path_points[aip->path_start+aip->path_length-2].pos, &Pl_objp->pos);
787 if ( aip->path_cur >= (aip->path_start+aip->path_length-1) ) {
791 min_dot = (target_objp->phys_info.fspeed > 5.0f?MIN_DOT_TO_ATTACK_MOVING_SUBSYS:MIN_DOT_TO_ATTACK_SUBSYS);
792 if ( (checked_sight && subsys_in_sight) && (dot > min_dot) ) {
796 // if we've reached the destination, then we can stop following the path
797 if ( path_done || ( dist < aip->path_goal_dist ) || in_view ) {
798 ai_big_subsys_path_cleanup(aip);
799 } else if ( dist > aip->path_goal_dist ) {
800 // If we have a path to follow, follow it and return
801 if ( aip->path_start != -1 ) {
802 // for now, only follow the path to the first point
803 if ( aip->path_cur < (aip->path_start+aip->path_length-1) ) {
804 if ( aip->goal_objnum != aip->target_objnum ) {
805 //Int3(); // what is going on here? - Get Alan
806 aip->previous_mode = aip->mode;
807 aip->mode = AIM_NONE;
822 // This function is only called from ai_big_chase_attack() when a ship is flying very slowly and
823 // attacking a big ship. The ship should scan for enemy fighter/bombers... if any are close, then
824 // return 1, otherwise return 0;
826 // input: aip => ai_info pointer for Pl_objp
827 // sip => ship_info pointer for Pl_objp
829 // exit: 1 => ship should enter strafe mode
830 // 0 => ship should not change ai mode, no fighter/bomber threats are near
832 // NOTE: uses SCAN_FIGHTERS_INTERVAL and ENTER_STRAFE_THREAT_DIST_SQUARED which are defined in AiBig.h
833 int ai_big_maybe_start_strafe(ai_info *aip, ship_info *sip)
835 // if moving slowly (or stopped), and SIF_SMALL_SHIP, then enter STRAFE mode if enemy fighter/bombers
837 if ( sip->flags & SIF_SMALL_SHIP ) {
838 if ( timestamp_elapsed(aip->scan_for_enemy_timestamp) ) {
844 aip->scan_for_enemy_timestamp = timestamp(SCAN_FIGHTERS_INTERVAL);
845 // iterate through ships, and see if any fighter/bomber from opposite team are near
846 so = GET_FIRST(&Ship_obj_list);
847 while( so != END_OF_LIST(&Ship_obj_list) ) {
848 test_objp = &Objects[so->objnum];
849 test_sp = &Ships[test_objp->instance];
851 if ( test_sp->team != Ships[Pl_objp->instance].team ) {
852 if ( Ship_info[test_sp->ship_info_index].flags & SIF_SMALL_SHIP ) {
853 dist_squared = vm_vec_dist_squared(&Pl_objp->pos, &test_objp->pos);
854 if ( dist_squared < ENTER_STRAFE_THREAT_DIST_SQUARED ) {
863 // If we've reached here, there are no enemy fighter/bombers near
867 // ATTACK submode handler for chase mode.
868 void ai_big_chase_attack(ai_info *aip, ship_info *sip, vector *enemy_pos, float dist_to_enemy)
871 float dot_to_enemy, time_to_hit;
872 polymodel *po = model_get( sip->modelnum );
874 // Maybe evade an incoming weapon.
875 if (((time_to_hit = ai_endangered_by_weapon(aip)) < 4.0f) && (time_to_hit >= 0.0f)) {
876 aip->submode = SM_EVADE_WEAPON;
877 aip->submode_start_time = Missiontime;
878 aip->prev_goal_point = En_objp->pos;
880 // If moving slowly, maybe evade incoming fire.
881 if (Pl_objp->phys_info.speed < 3.0f) {
883 for ( objp = GET_FIRST(&obj_used_list); objp !=END_OF_LIST(&obj_used_list); objp = GET_NEXT(objp) ) {
884 if ((objp->type == OBJ_WEAPON) && (Weapons[objp->instance].team != Ships[Pl_objp->instance].team))
885 if (Weapon_info[objp->instance].subtype == WP_LASER) {
889 vm_vec_sub(&in_vec, &objp->pos, &Pl_objp->pos);
890 if (vm_vec_dot(&in_vec, &objp->orient.v.fvec) > 0.0f) {
891 dist = vm_vec_normalize(&in_vec);
892 if ((dist < 200.0f) && (vm_vec_dot(&in_vec, &objp->orient.v.fvec) > 0.95f)) {
893 if ((Objects[objp->parent].signature == objp->parent_sig) && (vm_vec_dist_quick(&objp->pos, &Objects[objp->parent].pos) < 300.0f)) {
894 set_target_objnum(aip, objp->parent);
895 aip->submode = SM_ATTACK;
896 aip->submode_start_time = Missiontime;
898 aip->submode = SM_EVADE;
899 aip->submode_start_time = Missiontime;
900 aip->prev_goal_point = En_objp->pos;
907 // Since ship is moving slowly and attacking a large ship, scan if enemy fighters are near, if so
908 // then enter strafe mode
909 if ( ai_big_maybe_start_strafe(aip, sip) ) {
910 aip->previous_mode = aip->mode;
911 aip->mode = AIM_STRAFE;
912 aip->submode_parm0 = Missiontime; // use parm0 as time strafe mode entered
913 aip->submode = AIS_STRAFE_ATTACK;
914 aip->submode_start_time = Missiontime;
918 } // end if ( Pl_objp->phys_info.speed < 3.0f )
920 // see if Pl_objp needs to reposition to get a good shot at subsystem which is being attacked
921 if ( ai_big_maybe_follow_subsys_path() ) {
925 vector *rel_pos, vec_to_enemy;
926 float weapon_travel_dist;
928 start_bank = Ships[aip->shipnum].weapons.current_primary_bank;
930 if ((po->n_guns) && (start_bank != -1)) {
931 rel_pos = &po->gun_banks[start_bank].pnt[0];
935 dist_to_enemy = vm_vec_normalized_dir(&vec_to_enemy, enemy_pos, &Pl_objp->pos);
936 dot_to_enemy = vm_vec_dot(&vec_to_enemy, &Pl_objp->orient.v.fvec);
938 vector rvec_vec, *rvec = &rvec_vec;
940 if (dist_to_enemy > 500.0f)
941 compute_desired_rvec(rvec, enemy_pos, &Pl_objp->pos);
945 ai_turn_towards_vector(enemy_pos, Pl_objp, flFrametime, sip->srotation_time, NULL, rel_pos, 0.0f, 0, rvec);
947 // calc range of primary weapon
948 weapon_travel_dist = ai_get_weapon_dist(&Ships[Pl_objp->instance].weapons);
950 if ( aip->targeted_subsys != NULL ) {
951 if (dist_to_enemy > (weapon_travel_dist-20))
952 accelerate_ship(aip, 1.0f);
954 // AL 12-31-97: Move at least as quickly as your target is moving...
955 accelerate_ship(aip, SDL_max(1.0f - dot_to_enemy, Objects[aip->target_objnum].phys_info.fspeed/sip->max_speed));
960 if (dot_to_enemy < 0.0f) {
962 } else if (dot_to_enemy < 0.75f) {
965 if (dist_to_enemy > weapon_travel_dist/2.0f) {
968 accel = 1.0f - dot_to_enemy;
972 // use dist normal to enemy here (dont break 50 barrier)
973 if (dist_to_enemy < ATTACK_STOP_DISTANCE) {
974 // accelerate_ship(aip, accel * 0.5f);
975 accelerate_ship(aip, -1.0f);
977 accelerate_ship(aip, accel);
984 // Handler for submode SM_CONTINUOUS_TURN
985 void ai_big_chase_ct()
990 extern void ai_select_secondary_weapon(object *objp, ship_weapon *swp, int priority1 = -1, int priority2 = -1);
991 extern float set_secondary_fire_delay(ai_info *aip, ship *shipp, weapon_info *swip);
992 extern void ai_choose_secondary_weapon(object *objp, ai_info *aip, object *en_objp);
993 extern int maybe_avoid_big_ship(object *objp, object *ignore_objp, ai_info *aip, vector *goal_point, float delta_time);
995 extern void maybe_cheat_fire_synaptic(object *objp, ai_info *aip);
997 // Determine if Pl_objp should fire weapons at current target, based on input parameters
999 // dist_to_enemy => distance (in m) to attack point on current target
1000 // dot_to_enemy => dot product between fvec of Pl_objp and vector from Pl_objp to attack point
1002 void ai_big_maybe_fire_weapons(float dist_to_enemy, float dot_to_enemy, vector *firing_pos, vector *enemy_pos, vector *enemy_vel)
1007 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
1008 swp = &Ships[Pl_objp->instance].weapons;
1010 if (dot_to_enemy > 0.95f - 0.5f * En_objp->radius/SDL_max(1.0f, En_objp->radius + dist_to_enemy)) {
1011 aip->time_enemy_in_range += flFrametime;
1013 // Chance of hitting ship is based on dot product of firing ship's forward vector with vector to ship
1014 // and also the size of the target relative to distance to target.
1015 if (dot_to_enemy > SDL_max(0.5f, 0.90f + aip->ai_accuracy/10.0f - En_objp->radius/SDL_max(1.0f,dist_to_enemy))) {
1018 temp_shipp = &Ships[Pl_objp->instance];
1019 ship_weapon *tswp = &temp_shipp->weapons;
1021 if ( tswp->num_primary_banks > 0 ) {
1022 SDL_assert(tswp->current_primary_bank < tswp->num_primary_banks);
1023 weapon_info *wip = &Weapon_info[tswp->primary_bank_weapons[tswp->current_primary_bank]];
1025 if (dist_to_enemy < wip->max_speed * wip->lifetime)
1026 ai_fire_primary_weapon(Pl_objp);
1029 int priority1, priority2;
1034 // Maybe favor selecting a bomb.
1035 // Note, if you're firing a bomb, if it's aspect seeking, the firing conditions can be looser.
1036 if (Ship_info[Ships[En_objp->instance].ship_info_index].flags & (SIF_BIG_SHIP | SIF_HUGE_SHIP))
1037 if (En_objp->phys_info.speed * dist_to_enemy < 5000.0f) // Don't select a bomb if enemy moving fast relative to distance
1038 priority1 = WIF_BOMB;
1041 if (!(En_objp->flags & OF_PROTECTED)) {
1042 //ai_select_secondary_weapon(Pl_objp, tswp, priority1, priority2); // Note, need to select to get weapon speed and lifetime
1044 ai_choose_secondary_weapon(Pl_objp, aip, En_objp);
1045 int current_bank = tswp->current_secondary_bank;
1046 weapon_info *swip = &Weapon_info[tswp->secondary_bank_weapons[current_bank]];
1048 // If ship is protected and very low on hits, don't fire missiles.
1049 if ((current_bank > -1) && (!(En_objp->flags & OF_PROTECTED) || (En_objp->hull_strength > 10*swip->damage))) {
1050 if (aip->ai_flags & AIF_UNLOAD_SECONDARIES) {
1051 if (timestamp_until(swp->next_secondary_fire_stamp[current_bank]) > swip->fire_wait*1000.0f) {
1052 swp->next_secondary_fire_stamp[current_bank] = timestamp((int) (swip->fire_wait*1000.0f));
1056 if (timestamp_elapsed(swp->next_secondary_fire_stamp[current_bank])) {
1058 float firing_range = swip->max_speed * swip->lifetime;
1059 // reduce firing range of secondaries in nebula
1060 extern int Nebula_sec_range;
1061 if ((The_mission.flags & MISSION_FLAG_FULLNEB) && Nebula_sec_range) {
1062 firing_range *= 0.8f;
1065 float t = 0.25f; // default delay in seconds until next fire.
1067 if (dist_to_enemy < firing_range*1.0f) {
1070 //vm_vec_scale_add(&future_enemy_pos, enemy_pos, enemy_vel, dist_to_enemy/swip->max_speed);
1071 //if (vm_vec_dist_quick(&future_enemy_pos, firing_pos) < firing_range * 0.8f) {
1072 if (ai_fire_secondary_weapon(Pl_objp)) {
1073 if (aip->ai_flags & AIF_UNLOAD_SECONDARIES) {
1074 t = swip->fire_wait;
1076 t = set_secondary_fire_delay(aip, temp_shipp, swip);
1079 swp->next_secondary_fire_stamp[current_bank] = timestamp((int) (t*1000.0f));
1083 swp->next_secondary_fire_stamp[current_bank] = timestamp((int) (t*1000.0f));
1090 aip->time_enemy_in_range *= (1.0f - flFrametime);
1094 // switch ai ship into chase mode
1095 void ai_big_switch_to_chase_mode(ai_info *aip)
1097 aip->previous_mode = aip->mode;
1098 aip->mode = AIM_CHASE;
1099 aip->submode = SM_ATTACK;
1100 aip->submode_start_time = Missiontime;
1103 extern int ai_big_strafe_maybe_retreat(float dist, vector *target_pos);
1105 // Make object Pl_objp chase object En_objp, which is a big ship, not a small ship.
1108 float dist_to_enemy, dot_to_enemy;
1109 vector player_pos, enemy_pos, vec_to_enemy;
1110 ship_info *sip = &Ship_info[Ships[Pl_objp->instance].ship_info_index];
1111 ship *shipp = &Ships[Pl_objp->instance];
1112 ai_info *aip = &Ai_info[shipp->ai_index];
1113 vector predicted_enemy_pos;
1115 SDL_assert(aip->mode == AIM_CHASE);
1117 maybe_cheat_fire_synaptic(Pl_objp, aip);
1119 ai_set_positions(Pl_objp, En_objp, aip, &player_pos, &enemy_pos);
1121 player_pos = Pl_objp->pos;
1122 ai_big_pick_attack_point(En_objp, Pl_objp, &enemy_pos, 0.8f);
1124 // Compute the predicted position of the center of the ship, then add the delta to the goal pos.
1125 if (En_objp->phys_info.speed > 3.0f) {
1126 set_predicted_enemy_pos(&predicted_enemy_pos, Pl_objp, En_objp, aip);
1127 vm_vec_add2(&enemy_pos, &predicted_enemy_pos);
1128 vm_vec_sub2(&enemy_pos, &En_objp->pos);
1130 predicted_enemy_pos = En_objp->pos;
1132 if (aip->targeted_subsys != NULL) {
1133 get_subsystem_pos(&enemy_pos, En_objp, aip->targeted_subsys);
1136 dist_to_enemy = vm_vec_normalized_dir(&vec_to_enemy, &enemy_pos, &player_pos); // - En_objp->radius;
1137 dot_to_enemy = vm_vec_dot(&vec_to_enemy, &Pl_objp->orient.v.fvec);
1139 if (aip->ai_flags & AIF_TARGET_COLLISION) {
1140 if ( ai_big_strafe_maybe_retreat(dist_to_enemy, &enemy_pos) ) {
1141 aip->mode = AIM_STRAFE;
1142 aip->submode = AIS_STRAFE_AVOID;
1143 aip->submode_parm0 = Missiontime; // use parm0 as time strafe mode entered
1148 if (aip->ai_flags & AIF_KAMIKAZE) {
1149 //nprintf(("AI", "Kamikaze: %7.3f %7.3f\n", dot_to_enemy, dist_to_enemy));
1150 accelerate_ship(aip, 1.0f);
1151 if ((dist_to_enemy < 400.0f) && ai_maybe_fire_afterburner(Pl_objp, aip)) {
1152 afterburners_start(Pl_objp);
1153 aip->afterburner_stop_time = Missiontime + 3*F1_0;
1157 // If just acquired target, or target is not in reasonable cone, don't refine believed enemy position.
1158 if ((dot_to_enemy < 0.25f) || (aip->target_time < 1.0f) || (aip->ai_flags & AIF_SEEK_LOCK)) {
1159 update_aspect_lock_information(aip, &vec_to_enemy, dist_to_enemy - En_objp->radius, En_objp->radius);
1160 } else if (aip->targeted_subsys != NULL) {
1161 SDL_assert(aip->targeted_subsys != NULL);
1162 get_subsystem_pos(&enemy_pos, En_objp, aip->targeted_subsys);
1163 vm_vec_add2(&enemy_pos, &predicted_enemy_pos);
1164 vm_vec_sub2(&enemy_pos, &En_objp->pos);
1165 dist_to_enemy = vm_vec_normalized_dir(&vec_to_enemy, &enemy_pos, &player_pos); // - En_objp->radius;
1166 dot_to_enemy = vm_vec_dot(&vec_to_enemy, &Pl_objp->orient.v.fvec);
1167 update_aspect_lock_information(aip, &vec_to_enemy, dist_to_enemy, En_objp->radius);
1168 } else if (En_objp->flags & OF_PROTECTED) { // If protected and we're not attacking a subsystem, stop attacking!
1169 update_aspect_lock_information(aip, &vec_to_enemy, dist_to_enemy - En_objp->radius, En_objp->radius);
1170 aip->target_objnum = -1;
1171 if (find_enemy(Pl_objp-Objects, MAX_ENEMY_DISTANCE, Skill_level_max_attackers[Game_skill_level]) == -1) {
1172 ai_do_default_behavior(Pl_objp);
1176 update_aspect_lock_information(aip, &vec_to_enemy, dist_to_enemy - En_objp->radius, En_objp->radius);
1179 // If recently acquired target and not looking at target, just turn a bit.
1180 switch (aip->submode) {
1182 case SM_SUPER_ATTACK:
1183 if (vm_vec_dist_quick(&Pl_objp->pos, &predicted_enemy_pos) > 100.0f + En_objp->radius * 2.0f) {
1184 if (maybe_avoid_big_ship(Pl_objp, En_objp, aip, &predicted_enemy_pos, 10.0f))
1188 if (aip->target_time < 2.0f)
1189 if ((dot_to_enemy < 0.9f) || (dist_to_enemy > 300.0f)) {
1190 aip->submode = SM_CONTINUOUS_TURN;
1191 aip->submode_start_time = Missiontime - fl2f(2.75f); // This backdated start time allows immediate switchout.
1192 if (dot_to_enemy > 0.0f)
1193 aip->target_time += flFrametime * dot_to_enemy;
1199 // Set turn and acceleration based on submode.
1201 switch (aip->submode) {
1202 case SM_CONTINUOUS_TURN:
1207 case SM_SUPER_ATTACK:
1208 case SM_ATTACK_FOREVER:
1209 ai_big_chase_attack(aip, sip, &enemy_pos, dist_to_enemy);
1213 ai_big_evade_ship();
1217 ai_big_avoid_ship();
1220 case SM_EVADE_WEAPON:
1225 aip->last_attack_time = Missiontime;
1226 aip->submode = SM_ATTACK;
1230 // maybe Pl_objp was forced into strafe mode, if so return now
1231 if ( aip->mode == AIM_STRAFE )
1234 // Maybe choose a new submode.
1235 if (aip->submode != SM_AVOID && aip->submode != SM_EVADE ) {
1236 // If a very long time since attacked, attack no matter what!
1237 if (aip->submode != SM_SUPER_ATTACK) {
1238 if (Missiontime - aip->last_attack_time > i2f(6)) {
1239 aip->submode = SM_SUPER_ATTACK;
1240 aip->submode_start_time = Missiontime;
1241 aip->last_attack_time = Missiontime;
1245 // If a collision is expected, pull out!
1246 float dist_normal_to_enemy;
1248 if (vm_vec_mag_squared(&aip->big_attack_surface_normal) > 0.9) {
1249 dist_normal_to_enemy = fl_abs((dist_to_enemy * vm_vec_dot(&vec_to_enemy, &aip->big_attack_surface_normal)));
1251 // don;t have normal so use a conservative value here
1252 dist_normal_to_enemy = 0.3f * dist_to_enemy;
1255 // 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));
1256 // if (Framecount % 30 == 1) {
1257 // mprintf(("normal dist; %.1f, time: %.1f\n", dist_normal_to_enemy, time_to_enemy));
1260 // 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)
1261 // this will allow us to get closer on a bad normal
1262 dist_normal_to_enemy = SDL_max(0.3f*dist_to_enemy, dist_normal_to_enemy);
1264 if (dist_to_enemy < ATTACK_COLLIDE_BASE_DIST) {
1265 // within 50m or 1sec
1266 float time_to_enemy;
1267 if (vm_vec_mag_squared(&aip->big_attack_surface_normal) > 0.9) {
1268 if (Pl_objp->phys_info.speed > 0.1) {
1269 time_to_enemy = dist_normal_to_enemy / fl_abs(vm_vec_dot(&Pl_objp->phys_info.vel, &aip->big_attack_surface_normal));
1272 time_to_enemy = 100.0f;
1275 if (Pl_objp->phys_info.speed > 0.1) {
1276 time_to_enemy = dist_normal_to_enemy / Pl_objp->phys_info.speed;
1279 time_to_enemy = 100.0f;
1283 float speed_dist = SDL_max(0.0f, (Pl_objp->phys_info.speed-50) * 2);
1284 if ((dist_normal_to_enemy < ATTACK_COLLIDE_AVOID_DIST + speed_dist) || (time_to_enemy < ATTACK_COLLIDE_AVOID_TIME) ) {
1285 // get away, simulate crsh recovery (don't use avoid)
1286 // accelerate_ship(aip, -1.0f);
1287 big_ship_collide_recover_start(Pl_objp, En_objp, &Pl_objp->pos, NULL);
1288 // aip->submode = SM_AVOID;
1289 // aip->submode_start_time = Missiontime;
1290 } else if ((dist_normal_to_enemy < ATTACK_COLLIDE_SLOW_DIST) || (time_to_enemy < ATTACK_COLLIDE_SLOW_TIME) ) {
1292 accelerate_ship(aip, -1.0f);
1297 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)) {
1298 if (might_collide_with_ship(Pl_objp, En_objp, dot_to_enemy, dist_to_enemy, (aip->targeted_subsys == NULL)*2.0f + 1.5f)) {
1299 if ((Missiontime - aip->last_hit_time > F1_0*4) && (dist_to_enemy < Pl_objp->radius*2 + En_objp->radius*2)) {
1300 accelerate_ship(aip, -1.0f);
1302 aip->submode = SM_AVOID;
1303 aip->submode_start_time = Missiontime;
1309 switch (aip->submode) {
1310 case SM_CONTINUOUS_TURN:
1311 if (Missiontime - aip->submode_start_time > i2f(3)) {
1312 aip->last_attack_time = Missiontime;
1313 aip->submode = SM_ATTACK;
1314 aip->submode_start_time = Missiontime;
1319 case SM_ATTACK_FOREVER:
1323 if (dist_to_enemy > 4*En_objp->radius) {
1324 aip->submode = SM_ATTACK;
1325 aip->submode_start_time = Missiontime;
1326 aip->last_attack_time = Missiontime;
1330 case SM_SUPER_ATTACK:
1334 // if outside box by > 300 m
1335 // DA 4/20/98 can never get here attacking a big ship
1338 float box_dist = get_world_closest_box_point_with_delta(NULL, En_objp, &Pl_objp->pos, &is_inside, 0.0f);
1340 if (box_dist > 300) {
1341 aip->submode = SM_ATTACK;
1342 aip->last_attack_time = Missiontime;
1343 aip->submode_start_time = Missiontime;
1348 /* if (dot_to_enemy > -0.2f) {
1349 aip->submode_start_time = Missiontime;
1350 } else if (Missiontime - aip->submode_start_time > i2f(1)/2) {
1351 if (might_collide_with_ship(Pl_objp, En_objp, dot_to_enemy, dist_to_enemy, 3.0f)) {
1352 aip->submode_start_time = Missiontime;
1354 aip->submode = SM_ATTACK;
1355 aip->last_attack_time = Missiontime;
1356 aip->submode_start_time = Missiontime;
1362 case SM_EVADE_WEAPON:
1363 if (aip->danger_weapon_objnum == -1) {
1364 aip->submode = SM_ATTACK;
1365 aip->submode_start_time = Missiontime;
1366 aip->last_attack_time = Missiontime;
1371 aip->submode = SM_ATTACK;
1372 aip->last_attack_time = Missiontime;
1373 aip->submode_start_time = Missiontime;
1377 // Maybe fire primary weapon and update time_enemy_in_range
1379 //nprintf(("AI", "time_enemy_in_range = %7.3f, dot = %7.3f\n", aip->time_enemy_in_range, dot_to_enemy));
1381 // AL: add condition that Pl_objp must not be following a path to fire. This may be too extreme, but
1382 // I noticed AI ships firing inappropriately when following a path near a big ship.
1383 // TODO: investigate why ships fire (and aren't close to hitting ship) when following a path near
1385 if (aip->mode != AIM_EVADE && aip->path_start == -1 ) {
1386 ai_big_maybe_fire_weapons(dist_to_enemy, dot_to_enemy, &player_pos, &predicted_enemy_pos, &En_objp->phys_info.vel);
1388 aip->time_enemy_in_range *= (1.0f - flFrametime);
1391 void ai_big_ship(object *objp)
1396 // all three parms are output parameters
1397 // Enemy object is En_objp
1398 // pos => world pos of attack point
1399 // dist => distance from Pl_objp front to attack point
1400 // dot => dot of Pl_objp fvec and vector to attack point
1401 // fire_pos => world pos from which firing
1402 void ai_big_attack_get_data(vector *enemy_pos, float *dist_to_enemy, float *dot_to_enemy)
1404 vector player_pos, vec_to_enemy, predicted_enemy_pos;
1405 ship *shipp = &Ships[Pl_objp->instance];
1406 ai_info *aip = &Ai_info[shipp->ai_index];
1407 ship_info *esip = &Ship_info[Ships[En_objp->instance].ship_info_index];
1409 SDL_assert(aip->mode == AIM_STRAFE);
1411 // ensure that Pl_objp is still targeting a big ship
1412 if ( !(esip->flags & (SIF_BIG_SHIP | SIF_HUGE_SHIP)) ) {
1413 ai_big_switch_to_chase_mode(aip);
1417 ai_set_positions(Pl_objp, En_objp, aip, &player_pos, enemy_pos);
1419 player_pos = Pl_objp->pos;
1421 if (aip->targeted_subsys != NULL) {
1422 SDL_assert(aip->targeted_subsys != NULL);
1423 get_subsystem_pos(enemy_pos, En_objp, aip->targeted_subsys);
1425 // checks valid line to target
1426 ai_big_pick_attack_point(En_objp, Pl_objp, enemy_pos, 0.8f);
1429 // Take player pos to be center of ship + ship_radius
1430 vm_vec_scale_add2(&player_pos, &Pl_objp->orient.v.fvec, Pl_objp->radius);
1432 // If seeking lock, try to point directly at ship, else predict position so lasers can hit it.
1433 // If just acquired target, or target is not in reasonable cone, don't refine believed enemy position.
1434 vm_vec_normalized_dir(&vec_to_enemy, enemy_pos, &player_pos);
1435 *dot_to_enemy=vm_vec_dot(&vec_to_enemy, &Pl_objp->orient.v.fvec);
1436 if ((*dot_to_enemy < 0.25f) || (aip->target_time < 1.0f) || (aip->ai_flags & AIF_SEEK_LOCK)) {
1437 predicted_enemy_pos=*enemy_pos;
1439 vector gun_pos, pnt;
1440 polymodel *po = model_get( Ship_info[shipp->ship_info_index].modelnum );
1443 // Compute position of gun in absolute space and use that as fire position.
1444 pnt = po->gun_banks[0].pnt[0];
1445 vm_vec_unrotate(&gun_pos, &pnt, &Pl_objp->orient);
1446 vm_vec_add2(&gun_pos, &Pl_objp->pos);
1447 weapon_speed = ai_get_weapon_speed(&shipp->weapons);
1449 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);
1452 *dist_to_enemy = vm_vec_normalized_dir(&vec_to_enemy, &predicted_enemy_pos, &player_pos);
1453 *dot_to_enemy = vm_vec_dot(&vec_to_enemy, &Pl_objp->orient.v.fvec);
1454 update_aspect_lock_information(aip, &vec_to_enemy, *dist_to_enemy, En_objp->radius);
1456 *enemy_pos = predicted_enemy_pos;
1459 // check to see if Pl_objp has gotten too close to attacking point.. if so, break off by entering
1460 // AIS_STRAFE_RETREAT
1461 int ai_big_strafe_maybe_retreat(float dist, vector *target_pos)
1464 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
1466 vector vec_to_target;
1467 vm_vec_sub(&vec_to_target, target_pos, &Pl_objp->pos);
1469 float dist_to_target, dist_normal_to_target, time_to_target;
1470 dist_to_target = vm_vec_mag_quick(&vec_to_target);
1471 if (vm_vec_mag_quick(&aip->big_attack_surface_normal) > 0.9) {
1472 dist_normal_to_target = -vm_vec_dotprod(&vec_to_target, &aip->big_attack_surface_normal);
1474 dist_normal_to_target = 0.2f * vm_vec_mag_quick(&vec_to_target);
1477 dist_normal_to_target = SDL_max(0.2f*dist_to_target, dist_normal_to_target);
1478 time_to_target = dist_normal_to_target / Pl_objp->phys_info.speed;
1480 // add distance penalty for going too fast
1481 float speed_to_dist_penalty = SDL_max(0.0f, (Pl_objp->phys_info.speed-50));
1483 //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))
1485 // Inside 2 sec retreat, setting goal point to box point + 300m
1486 // If collision, use std collision resolution.
1487 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)) ) {
1488 if (aip->ai_flags & AIF_TARGET_COLLISION) {
1489 // use standard collision resolution
1490 aip->ai_flags &= ~AIF_TARGET_COLLISION;
1491 big_ship_collide_recover_start(Pl_objp, En_objp, &Pl_objp->pos, NULL);
1493 // too close for comfort so fly to box point + 300
1494 aip->submode = AIS_STRAFE_RETREAT1;
1495 aip->submode_start_time = Missiontime;
1499 get_world_closest_box_point_with_delta(&goal_point, En_objp, &Pl_objp->pos, &is_inside, STRAFE_RETREAT_BOX_DIST);
1502 aip->goal_point = goal_point;
1504 if (ai_maybe_fire_afterburner(Pl_objp, aip)) {
1505 afterburners_start(Pl_objp);
1506 aip->afterburner_stop_time = Missiontime + 3*F1_0;
1516 // attack directly to the turret and fire weapons
1517 void ai_big_strafe_attack()
1522 float target_dist = 0.0f, target_dot = 0.0f, accel, t;
1524 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
1526 if ( ai_big_maybe_follow_subsys_path(0) ) {
1530 ai_big_attack_get_data(&target_pos, &target_dist, &target_dot);
1531 if ( ai_big_strafe_maybe_retreat(target_dist, &target_pos) )
1534 if (aip->ai_flags & AIF_KAMIKAZE) {
1535 if (target_dist < 1200.0f) {
1536 //nprintf(("AI", "Kamikaze: %7.3f %7.3f\n", target_dot, target_dist));
1537 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);
1538 accelerate_ship(aip, 1.0f);
1539 if ((target_dist < 400.0f) && ai_maybe_fire_afterburner(Pl_objp, aip)) {
1540 afterburners_start(Pl_objp);
1541 aip->afterburner_stop_time = Missiontime + 3*F1_0;
1547 if (!(aip->ai_flags & AIF_SEEK_LOCK) || (aip->aspect_locked_time < 2.0f)) {
1548 t = ai_endangered_by_weapon(aip);
1549 if ( t > 0.0f && t < 1.5f ) {
1550 // set up goal_point for avoid path to turn towards
1551 aip->goal_point = Pl_objp->pos;
1554 vm_vec_scale_add(&rand_vec, &Pl_objp->orient.v.fvec, &Pl_objp->orient.v.uvec, 2.0f);
1557 vm_vec_scale_add(&rand_vec, &Pl_objp->orient.v.fvec, &Pl_objp->orient.v.uvec, -2.0f);
1560 vm_vec_scale_add(&rand_vec, &Pl_objp->orient.v.fvec, &Pl_objp->orient.v.rvec, 2.0f);
1563 vm_vec_scale_add(&rand_vec, &Pl_objp->orient.v.fvec, &Pl_objp->orient.v.rvec, -2.0f);
1567 vm_vec_scale(&rand_vec, 1000.0f);
1568 vm_vec_add2(&aip->goal_point, &rand_vec);
1570 aip->submode = AIS_STRAFE_AVOID;
1571 aip->submode_start_time = Missiontime;
1572 // nprintf(("Alan","Ship %s entering AIS_STRAFE_AVOID at frame %d\n", Ships[aip->shipnum].ship_name, Framecount));
1574 if (ai_maybe_fire_afterburner(Pl_objp, aip)) {
1575 afterburners_start(Pl_objp);
1576 aip->afterburner_stop_time = Missiontime + fl2f(0.5f);
1581 // maybe fire weapons at target
1582 ai_big_maybe_fire_weapons(target_dist, target_dot, &Pl_objp->pos, &En_objp->pos, &En_objp->phys_info.vel);
1583 turn_towards_point(Pl_objp, &target_pos, NULL, 0.0f);
1585 // Slow down if we've not been hit for a while
1586 fix last_hit = Missiontime - aip->last_hit_time;
1588 if ( target_dist > 1200 || last_hit < F1_0*6) {
1592 attack_time = f2fl(Missiontime - aip->submode_start_time);
1593 if ( attack_time > 15 ) {
1595 } else if ( attack_time > 10 ) {
1597 } else if ( attack_time > 8 ) {
1599 } else if ( attack_time > 5 ) {
1608 accelerate_ship(aip, accel);
1610 // if haven't been hit in quite a while, leave strafe mode
1612 long_enough = F1_0*20;
1613 if ( (last_hit > long_enough) && ( (Missiontime - aip->submode_parm0) > long_enough) ) {
1614 ai_big_switch_to_chase_mode(aip);
1618 // pick a new attack point when entering this state, and keep using it
1619 void ai_big_strafe_avoid()
1623 float target_dist, target_dot;
1626 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
1628 mode_time = Missiontime - aip->submode_start_time;
1630 ai_big_attack_get_data(&target_pos, &target_dist, &target_dot);
1631 if ( ai_big_strafe_maybe_retreat(target_dist, &target_pos) )
1634 if ( mode_time > fl2f(0.5)) {
1635 aip->submode = AIS_STRAFE_ATTACK;
1636 aip->submode_start_time = Missiontime;
1637 // nprintf(("Alan","Ship %s entering AIS_STRAFE_ATTACK at frame %d\n", Ships[aip->shipnum].ship_name, Framecount));
1640 turn_towards_point(Pl_objp, &aip->goal_point, NULL, 0.0f);
1641 accelerate_ship(aip, 1.0f);
1644 // move towards aip->goal_point in an evasive manner
1645 void ai_big_strafe_retreat1()
1651 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
1653 dist = vm_vec_dist_quick(&Pl_objp->pos, &aip->goal_point);
1655 aip->submode = AIS_STRAFE_POSITION;
1656 aip->submode_start_time = Missiontime;
1657 // nprintf(("Alan","Ship %s entering AIS_STRAFE_POSITION\n", Ships[aip->shipnum].ship_name));
1661 if (Missiontime - aip->submode_start_time > fl2f(1.50f)) {
1662 // set up goal_point for avoid path to turn towards
1663 aip->prev_goal_point = Pl_objp->pos;
1666 vm_vec_add(&rand_vec, &Pl_objp->orient.v.fvec, &Pl_objp->orient.v.uvec);
1669 vm_vec_scale_add(&rand_vec, &Pl_objp->orient.v.fvec, &Pl_objp->orient.v.uvec, -1.0f);
1672 vm_vec_add(&rand_vec, &Pl_objp->orient.v.fvec, &Pl_objp->orient.v.rvec);
1675 vm_vec_scale_add(&rand_vec, &Pl_objp->orient.v.fvec, &Pl_objp->orient.v.rvec, -1.0f);
1679 //vm_vec_scale(&rand_vec, 200.0f);
1680 //vm_vec_add2(&aip->prev_goal_point, &rand_vec);
1681 vm_vec_scale_add(&aip->prev_goal_point, &aip->goal_point, &rand_vec, 200.0f);
1683 aip->submode = AIS_STRAFE_RETREAT2;
1684 aip->submode_start_time = Missiontime;
1687 turn_towards_point(Pl_objp, &aip->goal_point, NULL, 0.0f);
1688 accelerate_ship(aip, 1.0f);
1691 void ai_big_strafe_retreat2()
1696 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
1698 if (Pl_objp->phys_info.flags & PF_AFTERBURNER_ON ) {
1699 if (Missiontime > aip->afterburner_stop_time) {
1700 //nprintf(("AI", "Frame %i, turning off afterburner.\n", AI_FrameCount));
1701 afterburners_stop(Pl_objp);
1705 dist = vm_vec_dist_quick(&Pl_objp->pos, &aip->goal_point);
1707 aip->submode = AIS_STRAFE_POSITION;
1708 aip->submode_start_time = Missiontime;
1709 // nprintf(("Alan","Ship %s entering AIS_STRAFE_POSITION\n", Ships[aip->shipnum].ship_name));
1713 if (Missiontime - aip->submode_start_time > fl2f(0.70f)) {
1714 aip->submode = AIS_STRAFE_RETREAT1;
1715 aip->submode_start_time = Missiontime;
1717 if ( (Missiontime - aip->last_hit_time) < F1_0*5 ) {
1718 if (ai_maybe_fire_afterburner(Pl_objp, aip)) {
1719 afterburners_start(Pl_objp);
1720 aip->afterburner_stop_time = Missiontime + F1_0;
1725 turn_towards_point(Pl_objp, &aip->prev_goal_point, NULL, 0.0f);
1726 accelerate_ship(aip, 1.0f);
1729 // reposition self to begin another strafing run
1730 void ai_big_strafe_position()
1733 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
1734 // TODO: loop around or something!!
1736 aip->submode = AIS_STRAFE_ATTACK;
1737 aip->submode_start_time = Missiontime;
1738 // nprintf(("Alan","Ship %s entering AIS_STRAFE_ATTACK\n", Ships[aip->shipnum].ship_name));
1741 // --------------------------------------------------------------------------
1742 // #define AIS_STRAFE_ATTACK 201 // fly towards target and attack
1743 // #define AIS_STRAFE_AVOID 202 // fly evasive vector to avoid incoming fire
1744 // #define AIS_STRAFE_RETREAT1 203 // fly away from attack point (directly)
1745 // #define AIS_STRAFE_RETREAT1 204 // fly away from attack point (on an avoid vector)
1746 // #define AIS_STRAFE_POSITION 205 // re-position to resume strafing attack
1748 void ai_big_strafe()
1752 aip = &Ai_info[Ships[Pl_objp->instance].ai_index];
1754 SDL_assert(aip->mode == AIM_STRAFE);
1757 if ( aip->goal_objnum != aip->target_objnum ) {
1758 Int3(); // what is going on here? - Get Alan
1759 aip->mode = AIM_NONE;
1764 // check if target is still a big ship... if not enter chase mode
1765 if ( !(Ship_info[Ships[En_objp->instance].ship_info_index].flags & (SIF_BIG_SHIP|SIF_HUGE_SHIP)) ) {
1766 ai_big_switch_to_chase_mode(aip);
1770 switch (aip->submode) {
1771 case AIS_STRAFE_ATTACK:
1772 ai_big_strafe_attack();
1774 case AIS_STRAFE_AVOID:
1775 ai_big_strafe_avoid();
1777 case AIS_STRAFE_RETREAT1:
1778 ai_big_strafe_retreat1();
1780 case AIS_STRAFE_RETREAT2:
1781 ai_big_strafe_retreat2();
1783 case AIS_STRAFE_POSITION:
1784 ai_big_strafe_position();
1788 Int3(); // Illegal submode for AIM_STRAFE
1793 // See if Pl_objp should enter strafe mode (This is called from maybe_evade_dumbfire_weapon(), and the
1794 // weapon_objnum is for a weapon that is about to collide with Pl_objp
1796 // Check if weapon_objnum was fired by Pl_objp's target, and whether Pl_objp's target is a big ship, if
1797 // so, enter AIM_STRAFE
1798 int ai_big_maybe_enter_strafe_mode(object *pl_objp, int weapon_objnum, int consider_target_only)
1802 object *weapon_objp, *parent_objp;
1804 aip = &Ai_info[Ships[pl_objp->instance].ai_index];
1805 SDL_assert(aip->mode != AIM_STRAFE); // can't happen
1807 // if Pl_objp has no target, then we can't enter strafe mode
1808 if ( aip->target_objnum < 0 ) {
1812 // if target is not a ship, stafe mode is not possible
1813 if ( Objects[aip->target_objnum].type != OBJ_SHIP ) {
1817 sip = &Ship_info[Ships[Objects[aip->target_objnum].instance].ship_info_index];
1819 // if Pl_objp's target is not a big/capital ship, then cannot enter strafe mode
1820 // AL 12-31-97: Even though transports are considered big ships, don't enter strafe mode on them
1821 if ( !(sip->flags & (SIF_BIG_SHIP | SIF_HUGE_SHIP)) || (sip->flags & SIF_TRANSPORT) ) {
1825 // If Pl_objp not a fighter or bomber, don't enter strafe mode. -- MK, 11/11/97.
1826 if ( !(Ship_info[Ships[pl_objp->instance].ship_info_index].flags & (SIF_FIGHTER | SIF_BOMBER)) ) {
1830 SDL_assert(weapon_objnum >= 0 && weapon_objnum < MAX_OBJECTS);
1831 weapon_objp = &Objects[weapon_objnum];
1832 SDL_assert(weapon_objp->type == OBJ_WEAPON);
1834 SDL_assert(weapon_objp->parent >= 0 && weapon_objp->parent < MAX_OBJECTS);
1835 parent_objp = &Objects[weapon_objp->parent];
1836 if ( (parent_objp->signature != weapon_objp->parent_sig) || (parent_objp->type != OBJ_SHIP) ) {
1840 // Maybe the ship which fired the weapon isn't the current target
1841 if ( OBJ_INDEX(parent_objp) != aip->target_objnum ) {
1843 //JAS IMPOSSIBLE if (1) { // consider_target_only ) {
1844 //JAS IMPOSSIBLE return 0;
1845 //JAS IMPOSSIBLE } else {
1847 sip = &Ship_info[Ships[parent_objp->instance].ship_info_index];
1848 if ( !(sip->flags & (SIF_BIG_SHIP | SIF_HUGE_SHIP)) || (sip->flags & SIF_TRANSPORT) ) {
1851 set_target_objnum(aip, OBJ_INDEX(parent_objp));
1855 ai_big_strafe_maybe_attack_turret(pl_objp, weapon_objp);
1857 // if we've got this far, the weapon must have come from the player's target, and it is a
1858 // big/capital ship... so enter strafe mode
1859 aip->previous_mode = aip->mode;
1860 aip->mode = AIM_STRAFE;
1861 aip->submode_parm0 = Missiontime; // use parm0 as time strafe mode entered
1862 aip->submode = AIS_STRAFE_AVOID;
1863 aip->submode_start_time = Missiontime;
1864 // nprintf(("Alan","%s Accepted strafe mode\n", Ships[pl_objp->instance].ship_name));
1869 // Consider attacking a turret, if a turret actually fired the weapon
1870 // input: ship_objp => ship that will attack the turret
1872 void ai_big_strafe_maybe_attack_turret(object *ship_objp, object *weapon_objp)
1875 object *parent_objp;
1877 SDL_assert(ship_objp->type == OBJ_SHIP);
1878 aip = &Ai_info[Ships[ship_objp->instance].ai_index];
1880 // Make decision to attack turret based on AI class. The better AI ships will realize that
1881 // it is better to take out the turrets first on a big ship.
1882 if ( (frand()*100) > (aip->ai_courage-15) )
1885 // If ship is already attacking a subsystem, don't switch
1886 if ( aip->targeted_subsys != NULL ) {
1890 // If the weapon is not from a turret, return
1891 if ( Weapons[weapon_objp->instance].turret_subsys == NULL ) {
1895 // Only attack turret if it sits on current target
1896 SDL_assert(weapon_objp->parent >= 0 && weapon_objp->parent < MAX_OBJECTS);
1897 parent_objp = &Objects[weapon_objp->parent];
1898 if ( (parent_objp->signature != weapon_objp->parent_sig) || (parent_objp->type != OBJ_SHIP) ) {
1902 if ( aip->target_objnum != OBJ_INDEX(parent_objp) ) {
1906 // attack the turret
1907 set_targeted_subsys(aip, Weapons[weapon_objp->instance].turret_subsys, OBJ_INDEX(parent_objp));