forked from JonnyPtn/SFML-DOOM
-
Notifications
You must be signed in to change notification settings - Fork 0
/
p_map.cpp
1339 lines (1042 loc) · 27.7 KB
/
p_map.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
// Emacs style mode select -*- C++ -*-
//-----------------------------------------------------------------------------
//
// $Id:$
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This source is available for distribution and/or modification
// only under the terms of the DOOM Source Code License as
// published by id Software. All rights reserved.
//
// The source is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
// for more details.
//
// $Log:$
//
// DESCRIPTION:
// Movement, collision handling.
// Shooting and aiming.
//
//-----------------------------------------------------------------------------
static const char
rcsid[] = "$Id: p_map.c,v 1.5 1997/02/03 22:45:11 b1 Exp $";
#include <stdlib.h>
#include "m_bbox.hpp"
#include "m_random.hpp"
#include "i_system.hpp"
#include "doomdef.hpp"
#include "p_local.hpp"
#include "s_sound.hpp"
// State.
#include "doomstat.hpp"
#include "r_state.hpp"
// Data.
#include "sounds.hpp"
fixed_t tmbbox[4];
mobj_t* tmthing;
int tmflags;
fixed_t tmx;
fixed_t tmy;
// If "floatok" true, move would be ok
// if within "tmfloorz - tmceilingz".
boolean floatok;
fixed_t tmfloorz;
fixed_t tmceilingz;
fixed_t tmdropoffz;
// keep track of the line that lowers the ceiling,
// so missiles don't explode against sky hack walls
line_t* ceilingline;
// keep track of special lines as they are hit,
// but don't process them until the move is proven valid
#define MAXSPECIALCROSS 8
line_t* spechit[MAXSPECIALCROSS];
int numspechit;
//
// TELEPORT MOVE
//
//
// PIT_StompThing
//
boolean PIT_StompThing (mobj_t* thing)
{
fixed_t blockdist;
if (!(thing->flags & MF_SHOOTABLE) )
return true;
blockdist = thing->radius + tmthing->radius;
if ( abs(thing->x - tmx) >= blockdist
|| abs(thing->y - tmy) >= blockdist )
{
// didn't hit it
return true;
}
// don't clip against self
if (thing == tmthing)
return true;
// monsters don't stomp things except on boss level
if ( !tmthing->player && gamemap != 30)
return false;
P_DamageMobj (thing, tmthing, tmthing, 10000);
return true;
}
//
// P_TeleportMove
//
boolean
P_TeleportMove
( mobj_t* thing,
fixed_t x,
fixed_t y )
{
int xl;
int xh;
int yl;
int yh;
int bx;
int by;
subsector_t* newsubsec;
// kill anything occupying the position
tmthing = thing;
tmflags = thing->flags;
tmx = x;
tmy = y;
tmbbox[BOXTOP] = y + tmthing->radius;
tmbbox[BOXBOTTOM] = y - tmthing->radius;
tmbbox[BOXRIGHT] = x + tmthing->radius;
tmbbox[BOXLEFT] = x - tmthing->radius;
newsubsec = R_PointInSubsector (x,y);
ceilingline = NULL;
// The base floor/ceiling is from the subsector
// that contains the point.
// Any contacted lines the step closer together
// will adjust them.
tmfloorz = tmdropoffz = newsubsec->sector->floorheight;
tmceilingz = newsubsec->sector->ceilingheight;
validcount++;
numspechit = 0;
// stomp on any things contacted
xl = (tmbbox[BOXLEFT] - bmaporgx - MAXRADIUS)>>MAPBLOCKSHIFT;
xh = (tmbbox[BOXRIGHT] - bmaporgx + MAXRADIUS)>>MAPBLOCKSHIFT;
yl = (tmbbox[BOXBOTTOM] - bmaporgy - MAXRADIUS)>>MAPBLOCKSHIFT;
yh = (tmbbox[BOXTOP] - bmaporgy + MAXRADIUS)>>MAPBLOCKSHIFT;
for (bx=xl ; bx<=xh ; bx++)
for (by=yl ; by<=yh ; by++)
if (!P_BlockThingsIterator(bx,by,PIT_StompThing))
return false;
// the move is ok,
// so link the thing into its new position
P_UnsetThingPosition (thing);
thing->floorz = tmfloorz;
thing->ceilingz = tmceilingz;
thing->x = x;
thing->y = y;
P_SetThingPosition (thing);
return true;
}
//
// MOVEMENT ITERATOR FUNCTIONS
//
//
// PIT_CheckLine
// Adjusts tmfloorz and tmceilingz as lines are contacted
//
boolean PIT_CheckLine (line_t* ld)
{
if (tmbbox[BOXRIGHT] <= ld->bbox[BOXLEFT]
|| tmbbox[BOXLEFT] >= ld->bbox[BOXRIGHT]
|| tmbbox[BOXTOP] <= ld->bbox[BOXBOTTOM]
|| tmbbox[BOXBOTTOM] >= ld->bbox[BOXTOP] )
return true;
if (P_BoxOnLineSide (tmbbox, ld) != -1)
return true;
// A line has been hit
// The moving thing's destination position will cross
// the given line.
// If this should not be allowed, return false.
// If the line is special, keep track of it
// to process later if the move is proven ok.
// NOTE: specials are NOT sorted by order,
// so two special lines that are only 8 pixels apart
// could be crossed in either order.
if (!ld->backsector)
return false; // one sided line
if (!(tmthing->flags & MF_MISSILE) )
{
if ( ld->flags & ML_BLOCKING )
return false; // explicitly blocking everything
if ( !tmthing->player && ld->flags & ML_BLOCKMONSTERS )
return false; // block monsters only
}
// set openrange, opentop, openbottom
P_LineOpening (ld);
// adjust floor / ceiling heights
if (opentop < tmceilingz)
{
tmceilingz = opentop;
ceilingline = ld;
}
if (openbottom > tmfloorz)
tmfloorz = openbottom;
if (lowfloor < tmdropoffz)
tmdropoffz = lowfloor;
// if contacted a special line, add it to the list
if (ld->special)
{
spechit[numspechit] = ld;
numspechit++;
}
return true;
}
//
// PIT_CheckThing
//
boolean PIT_CheckThing (mobj_t* thing)
{
fixed_t blockdist;
boolean solid;
int damage;
if (!(thing->flags & (MF_SOLID|MF_SPECIAL|MF_SHOOTABLE) ))
return true;
blockdist = thing->radius + tmthing->radius;
if ( abs(thing->x - tmx) >= blockdist
|| abs(thing->y - tmy) >= blockdist )
{
// didn't hit it
return true;
}
// don't clip against self
if (thing == tmthing)
return true;
// check for skulls slamming into things
if (tmthing->flags & MF_SKULLFLY)
{
damage = ((P_Random()%8)+1)*tmthing->info->damage;
P_DamageMobj (thing, tmthing, tmthing, damage);
tmthing->flags &= ~MF_SKULLFLY;
tmthing->momx = tmthing->momy = tmthing->momz = 0;
P_SetMobjState (tmthing, (statenum_t)tmthing->info->spawnstate);
return false; // stop moving
}
// missiles can hit other things
if (tmthing->flags & MF_MISSILE)
{
// see if it went over / under
if (tmthing->z > thing->z + thing->height)
return true; // overhead
if (tmthing->z+tmthing->height < thing->z)
return true; // underneath
if (tmthing->target && (
tmthing->target->type == thing->type ||
(tmthing->target->type == MT_KNIGHT && thing->type == MT_BRUISER)||
(tmthing->target->type == MT_BRUISER && thing->type == MT_KNIGHT) ) )
{
// Don't hit same species as originator.
if (thing == tmthing->target)
return true;
if (thing->type != MT_PLAYER)
{
// Explode, but do no damage.
// Let players missile other players.
return false;
}
}
if (! (thing->flags & MF_SHOOTABLE) )
{
// didn't do any damage
return !(thing->flags & MF_SOLID);
}
// damage / explode
damage = ((P_Random()%8)+1)*tmthing->info->damage;
P_DamageMobj (thing, tmthing, tmthing->target, damage);
// don't traverse any more
return false;
}
// check for special pickup
if (thing->flags & MF_SPECIAL)
{
solid = thing->flags&MF_SOLID;
if (tmflags&MF_PICKUP)
{
// can remove thing
P_TouchSpecialThing (thing, tmthing);
}
return !solid;
}
return !(thing->flags & MF_SOLID);
}
//
// MOVEMENT CLIPPING
//
//
// P_CheckPosition
// This is purely informative, nothing is modified
// (except things picked up).
//
// in:
// a mobj_t (can be valid or invalid)
// a position to be checked
// (doesn't need to be related to the mobj_t->x,y)
//
// during:
// special things are touched if MF_PICKUP
// early out on solid lines?
//
// out:
// newsubsec
// floorz
// ceilingz
// tmdropoffz
// the lowest point contacted
// (monsters won't move to a dropoff)
// speciallines[]
// numspeciallines
//
boolean
P_CheckPosition
( mobj_t* thing,
fixed_t x,
fixed_t y )
{
int xl;
int xh;
int yl;
int yh;
int bx;
int by;
subsector_t* newsubsec;
tmthing = thing;
tmflags = thing->flags;
tmx = x;
tmy = y;
tmbbox[BOXTOP] = y + tmthing->radius;
tmbbox[BOXBOTTOM] = y - tmthing->radius;
tmbbox[BOXRIGHT] = x + tmthing->radius;
tmbbox[BOXLEFT] = x - tmthing->radius;
newsubsec = R_PointInSubsector (x,y);
ceilingline = NULL;
// The base floor / ceiling is from the subsector
// that contains the point.
// Any contacted lines the step closer together
// will adjust them.
tmfloorz = tmdropoffz = newsubsec->sector->floorheight;
tmceilingz = newsubsec->sector->ceilingheight;
validcount++;
numspechit = 0;
if ( tmflags & MF_NOCLIP )
return true;
// Check things first, possibly picking things up.
// The bounding box is extended by MAXRADIUS
// because mobj_ts are grouped into mapblocks
// based on their origin point, and can overlap
// into adjacent blocks by up to MAXRADIUS units.
xl = (tmbbox[BOXLEFT] - bmaporgx - MAXRADIUS)>>MAPBLOCKSHIFT;
xh = (tmbbox[BOXRIGHT] - bmaporgx + MAXRADIUS)>>MAPBLOCKSHIFT;
yl = (tmbbox[BOXBOTTOM] - bmaporgy - MAXRADIUS)>>MAPBLOCKSHIFT;
yh = (tmbbox[BOXTOP] - bmaporgy + MAXRADIUS)>>MAPBLOCKSHIFT;
for (bx=xl ; bx<=xh ; bx++)
for (by=yl ; by<=yh ; by++)
if (!P_BlockThingsIterator(bx,by,PIT_CheckThing))
return false;
// check lines
xl = (tmbbox[BOXLEFT] - bmaporgx)>>MAPBLOCKSHIFT;
xh = (tmbbox[BOXRIGHT] - bmaporgx)>>MAPBLOCKSHIFT;
yl = (tmbbox[BOXBOTTOM] - bmaporgy)>>MAPBLOCKSHIFT;
yh = (tmbbox[BOXTOP] - bmaporgy)>>MAPBLOCKSHIFT;
for (bx=xl ; bx<=xh ; bx++)
for (by=yl ; by<=yh ; by++)
if (!P_BlockLinesIterator (bx,by,PIT_CheckLine))
return false;
return true;
}
//
// P_TryMove
// Attempt to move to a new position,
// crossing special lines unless MF_TELEPORT is set.
//
boolean
P_TryMove
( mobj_t* thing,
fixed_t x,
fixed_t y )
{
fixed_t oldx;
fixed_t oldy;
int side;
int oldside;
line_t* ld;
floatok = false;
if (!P_CheckPosition (thing, x, y))
return false; // solid wall or thing
if ( !(thing->flags & MF_NOCLIP) )
{
if (tmceilingz - tmfloorz < thing->height)
return false; // doesn't fit
floatok = true;
if ( !(thing->flags&MF_TELEPORT)
&&tmceilingz - thing->z < thing->height)
return false; // mobj must lower itself to fit
if ( !(thing->flags&MF_TELEPORT)
&& tmfloorz - thing->z > 24*FRACUNIT )
return false; // too big a step up
if ( !(thing->flags&(MF_DROPOFF|MF_FLOAT))
&& tmfloorz - tmdropoffz > 24*FRACUNIT )
return false; // don't stand over a dropoff
}
// the move is ok,
// so link the thing into its new position
P_UnsetThingPosition (thing);
oldx = thing->x;
oldy = thing->y;
thing->floorz = tmfloorz;
thing->ceilingz = tmceilingz;
thing->x = x;
thing->y = y;
P_SetThingPosition (thing);
// if any special lines were hit, do the effect
if (! (thing->flags&(MF_TELEPORT|MF_NOCLIP)) )
{
while (numspechit--)
{
// see if the line was crossed
ld = spechit[numspechit];
side = P_PointOnLineSide (thing->x, thing->y, ld);
oldside = P_PointOnLineSide (oldx, oldy, ld);
if (side != oldside)
{
if (ld->special)
P_CrossSpecialLine (ld-lines, oldside, thing);
}
}
}
return true;
}
//
// P_ThingHeightClip
// Takes a valid thing and adjusts the thing->floorz,
// thing->ceilingz, and possibly thing->z.
// This is called for all nearby monsters
// whenever a sector changes height.
// If the thing doesn't fit,
// the z will be set to the lowest value
// and false will be returned.
//
boolean P_ThingHeightClip (mobj_t* thing)
{
boolean onfloor;
onfloor = (thing->z == thing->floorz);
P_CheckPosition (thing, thing->x, thing->y);
// what about stranding a monster partially off an edge?
thing->floorz = tmfloorz;
thing->ceilingz = tmceilingz;
if (onfloor)
{
// walking monsters rise and fall with the floor
thing->z = thing->floorz;
}
else
{
// don't adjust a floating monster unless forced to
if (thing->z+thing->height > thing->ceilingz)
thing->z = thing->ceilingz - thing->height;
}
if (thing->ceilingz - thing->floorz < thing->height)
return false;
return true;
}
//
// SLIDE MOVE
// Allows the player to slide along any angled walls.
//
fixed_t bestslidefrac;
fixed_t secondslidefrac;
line_t* bestslideline;
line_t* secondslideline;
mobj_t* slidemo;
fixed_t tmxmove;
fixed_t tmymove;
//
// P_HitSlideLine
// Adjusts the xmove / ymove
// so that the next move will slide along the wall.
//
void P_HitSlideLine (line_t* ld)
{
int side;
angle_t lineangle;
angle_t moveangle;
angle_t deltaangle;
fixed_t movelen;
fixed_t newlen;
if (ld->slopetype == ST_HORIZONTAL)
{
tmymove = 0;
return;
}
if (ld->slopetype == ST_VERTICAL)
{
tmxmove = 0;
return;
}
side = P_PointOnLineSide (slidemo->x, slidemo->y, ld);
lineangle = R_PointToAngle2 (0,0, ld->dx, ld->dy);
if (side == 1)
lineangle += ANG180;
moveangle = R_PointToAngle2 (0,0, tmxmove, tmymove);
deltaangle = moveangle-lineangle;
if (deltaangle > ANG180)
deltaangle += ANG180;
// I_Error ("SlideLine: ang>ANG180");
lineangle >>= ANGLETOFINESHIFT;
deltaangle >>= ANGLETOFINESHIFT;
movelen = P_AproxDistance (tmxmove, tmymove);
newlen = FixedMul (movelen, finecosine[deltaangle]);
tmxmove = FixedMul (newlen, finecosine[lineangle]);
tmymove = FixedMul (newlen, finesine[lineangle]);
}
//
// PTR_SlideTraverse
//
boolean PTR_SlideTraverse (intercept_t* in)
{
line_t* li;
if (!in->isaline)
I_Error ("PTR_SlideTraverse: not a line?");
li = in->d.line;
if ( ! (li->flags & ML_TWOSIDED) )
{
if (P_PointOnLineSide (slidemo->x, slidemo->y, li))
{
// don't hit the back side
return true;
}
goto isblocking;
}
// set openrange, opentop, openbottom
P_LineOpening (li);
if (openrange < slidemo->height)
goto isblocking; // doesn't fit
if (opentop - slidemo->z < slidemo->height)
goto isblocking; // mobj is too high
if (openbottom - slidemo->z > 24*FRACUNIT )
goto isblocking; // too big a step up
// this line doesn't block movement
return true;
// the line does block movement,
// see if it is closer than best so far
isblocking:
if (in->frac < bestslidefrac)
{
secondslidefrac = bestslidefrac;
secondslideline = bestslideline;
bestslidefrac = in->frac;
bestslideline = li;
}
return false; // stop
}
//
// P_SlideMove
// The momx / momy move is bad, so try to slide
// along a wall.
// Find the first line hit, move flush to it,
// and slide along it
//
// This is a kludgy mess.
//
void P_SlideMove (mobj_t* mo)
{
fixed_t leadx;
fixed_t leady;
fixed_t trailx;
fixed_t traily;
fixed_t newx;
fixed_t newy;
int hitcount;
slidemo = mo;
hitcount = 0;
retry:
if (++hitcount == 3)
goto stairstep; // don't loop forever
// trace along the three leading corners
if (mo->momx > 0)
{
leadx = mo->x + mo->radius;
trailx = mo->x - mo->radius;
}
else
{
leadx = mo->x - mo->radius;
trailx = mo->x + mo->radius;
}
if (mo->momy > 0)
{
leady = mo->y + mo->radius;
traily = mo->y - mo->radius;
}
else
{
leady = mo->y - mo->radius;
traily = mo->y + mo->radius;
}
bestslidefrac = FRACUNIT+1;
P_PathTraverse ( leadx, leady, leadx+mo->momx, leady+mo->momy,
PT_ADDLINES, PTR_SlideTraverse );
P_PathTraverse ( trailx, leady, trailx+mo->momx, leady+mo->momy,
PT_ADDLINES, PTR_SlideTraverse );
P_PathTraverse ( leadx, traily, leadx+mo->momx, traily+mo->momy,
PT_ADDLINES, PTR_SlideTraverse );
// move up to the wall
if (bestslidefrac == FRACUNIT+1)
{
// the move most have hit the middle, so stairstep
stairstep:
if (!P_TryMove (mo, mo->x, mo->y + mo->momy))
P_TryMove (mo, mo->x + mo->momx, mo->y);
return;
}
// fudge a bit to make sure it doesn't hit
bestslidefrac -= 0x800;
if (bestslidefrac > 0)
{
newx = FixedMul (mo->momx, bestslidefrac);
newy = FixedMul (mo->momy, bestslidefrac);
if (!P_TryMove (mo, mo->x+newx, mo->y+newy))
goto stairstep;
}
// Now continue along the wall.
// First calculate remainder.
bestslidefrac = FRACUNIT-(bestslidefrac+0x800);
if (bestslidefrac > FRACUNIT)
bestslidefrac = FRACUNIT;
if (bestslidefrac <= 0)
return;
tmxmove = FixedMul (mo->momx, bestslidefrac);
tmymove = FixedMul (mo->momy, bestslidefrac);
P_HitSlideLine (bestslideline); // clip the moves
mo->momx = tmxmove;
mo->momy = tmymove;
if (!P_TryMove (mo, mo->x+tmxmove, mo->y+tmymove))
{
goto retry;
}
}
//
// P_LineAttack
//
mobj_t* linetarget; // who got hit (or NULL)
mobj_t* shootthing;
// Height if not aiming up or down
// ???: use slope for monsters?
fixed_t shootz;
int la_damage;
fixed_t attackrange;
fixed_t aimslope;
// slopes to top and bottom of target
extern fixed_t topslope;
extern fixed_t bottomslope;
//
// PTR_AimTraverse
// Sets linetaget and aimslope when a target is aimed at.
//
boolean
PTR_AimTraverse (intercept_t* in)
{
line_t* li;
mobj_t* th;
fixed_t slope;
fixed_t thingtopslope;
fixed_t thingbottomslope;
fixed_t dist;
if (in->isaline)
{
li = in->d.line;
if ( !(li->flags & ML_TWOSIDED) )
return false; // stop
// Crosses a two sided line.
// A two sided line will restrict
// the possible target ranges.
P_LineOpening (li);
if (openbottom >= opentop)
return false; // stop
dist = FixedMul (attackrange, in->frac);
if (li->frontsector->floorheight != li->backsector->floorheight)
{
slope = FixedDiv (openbottom - shootz , dist);
if (slope > bottomslope)
bottomslope = slope;
}
if (li->frontsector->ceilingheight != li->backsector->ceilingheight)
{
slope = FixedDiv (opentop - shootz , dist);
if (slope < topslope)
topslope = slope;
}
if (topslope <= bottomslope)
return false; // stop
return true; // shot continues
}
// shoot a thing
th = in->d.thing;
if (th == shootthing)
return true; // can't shoot self
if (!(th->flags&MF_SHOOTABLE))
return true; // corpse or something
// check angles to see if the thing can be aimed at
dist = FixedMul (attackrange, in->frac);
thingtopslope = FixedDiv (th->z+th->height - shootz , dist);
if (thingtopslope < bottomslope)
return true; // shot over the thing
thingbottomslope = FixedDiv (th->z - shootz, dist);
if (thingbottomslope > topslope)
return true; // shot under the thing
// this thing can be hit!
if (thingtopslope > topslope)
thingtopslope = topslope;
if (thingbottomslope < bottomslope)
thingbottomslope = bottomslope;
aimslope = (thingtopslope+thingbottomslope)/2;
linetarget = th;
return false; // don't go any farther
}
//
// PTR_ShootTraverse
//
boolean PTR_ShootTraverse (intercept_t* in)
{
fixed_t x;
fixed_t y;
fixed_t z;
fixed_t frac;
line_t* li;
mobj_t* th;
fixed_t slope;
fixed_t dist;
fixed_t thingtopslope;
fixed_t thingbottomslope;
if (in->isaline)
{
li = in->d.line;
if (li->special)
P_ShootSpecialLine (shootthing, li);
if ( !(li->flags & ML_TWOSIDED) )
goto hitline;
// crosses a two sided line
P_LineOpening (li);
dist = FixedMul (attackrange, in->frac);
if (li->frontsector->floorheight != li->backsector->floorheight)
{
slope = FixedDiv (openbottom - shootz , dist);
if (slope > aimslope)
goto hitline;
}
if (li->frontsector->ceilingheight != li->backsector->ceilingheight)
{
slope = FixedDiv (opentop - shootz , dist);
if (slope < aimslope)
goto hitline;
}
// shot continues
return true;
// hit line
hitline:
// position a bit closer
frac = in->frac - FixedDiv (4*FRACUNIT,attackrange);
x = trace.x + FixedMul (trace.dx, frac);
y = trace.y + FixedMul (trace.dy, frac);
z = shootz + FixedMul (aimslope, FixedMul(frac, attackrange));
if (li->frontsector->ceilingpic == skyflatnum)
{
// don't shoot the sky!
if (z > li->frontsector->ceilingheight)
return false;
// it's a sky hack wall
if (li->backsector && li->backsector->ceilingpic == skyflatnum)
return false;
}
// Spawn bullet puffs.
P_SpawnPuff (x,y,z);
// don't go any farther
return false;
}
// shoot a thing
th = in->d.thing;
if (th == shootthing)
return true; // can't shoot self
if (!(th->flags&MF_SHOOTABLE))
return true; // corpse or something
// check angles to see if the thing can be aimed at
dist = FixedMul (attackrange, in->frac);
thingtopslope = FixedDiv (th->z+th->height - shootz , dist);
if (thingtopslope < aimslope)
return true; // shot over the thing
thingbottomslope = FixedDiv (th->z - shootz, dist);
if (thingbottomslope > aimslope)
return true; // shot under the thing
// hit thing
// position a bit closer
frac = in->frac - FixedDiv (10*FRACUNIT,attackrange);
x = trace.x + FixedMul (trace.dx, frac);
y = trace.y + FixedMul (trace.dy, frac);