Annotation of 42BSD/games/trek/move.c, revision 1.1

1.1     ! root        1: #ifndef lint
        !             2: static char sccsid[] = "@(#)move.c     4.3     (Berkeley)      5/27/83";
        !             3: #endif not lint
        !             4: 
        !             5: # include      "trek.h"
        !             6: 
        !             7: /*
        !             8: **  Move Under Warp or Impulse Power
        !             9: **
        !            10: **     `Ramflag' is set if we are to be allowed to ram stars,
        !            11: **     Klingons, etc.  This is passed from warp(), which gets it from
        !            12: **     either play() or ram().  Course is the course (0 -> 360) at
        !            13: **     which we want to move.  `Speed' is the speed we
        !            14: **     want to go, and `time' is the expected time.  It
        !            15: **     can get cut short if a long range tractor beam is to occur.  We
        !            16: **     cut short the move so that the user doesn't get docked time and
        !            17: **     energy for distance which he didn't travel.
        !            18: **
        !            19: **     We check the course through the current quadrant to see that he
        !            20: **     doesn't run into anything.  After that, though, space sort of
        !            21: **     bends around him.  Note that this puts us in the awkward posi-
        !            22: **     tion of being able to be dropped into a sector which is com-
        !            23: **     pletely surrounded by stars.  Oh Well.
        !            24: **
        !            25: **     If the SINS (Space Inertial Navigation System) is out, we ran-
        !            26: **     domize the course accordingly before ever starting to move.
        !            27: **     We will still move in a straight line.
        !            28: **
        !            29: **     Note that if your computer is out, you ram things anyway.  In
        !            30: **     other words, if your computer and sins are both out, you're in
        !            31: **     potentially very bad shape.
        !            32: **
        !            33: **     Klingons get a chance to zap you as you leave the quadrant.
        !            34: **     By the way, they also try to follow you (heh heh).
        !            35: **
        !            36: **     Return value is the actual amount of time used.
        !            37: **
        !            38: **
        !            39: **     Uses trace flag 4.
        !            40: */
        !            41: 
        !            42: double move(ramflag, course, time, speed)
        !            43: int    ramflag;
        !            44: int    course;
        !            45: double time;
        !            46: double speed;
        !            47: {
        !            48:        double                  angle;
        !            49:        double                  x, y, dx, dy;
        !            50:        register int            ix, iy;
        !            51:        double                  bigger;
        !            52:        int                     n;
        !            53:        register int            i;
        !            54:        double                  dist;
        !            55:        double                  sectsize;
        !            56:        double                  xn;
        !            57:        double                  evtime;
        !            58: 
        !            59: #      ifdef xTRACE
        !            60:        if (Trace)
        !            61:                printf("move: ramflag %d course %d time %.2f speed %.2f\n",
        !            62:                        ramflag, course, time, speed);
        !            63: #      endif
        !            64:        sectsize = NSECTS;
        !            65:        /* initialize delta factors for move */
        !            66:        angle = course * 0.0174532925;
        !            67:        if (damaged(SINS))
        !            68:                angle += Param.navigcrud[1] * (franf() - 0.5);
        !            69:        else
        !            70:                if (Ship.sinsbad)
        !            71:                        angle += Param.navigcrud[0] * (franf() - 0.5);
        !            72:        dx = -cos(angle);
        !            73:        dy = sin(angle);
        !            74:        bigger = fabs(dx);
        !            75:        dist = fabs(dy);
        !            76:        if (dist > bigger)
        !            77:                bigger = dist;
        !            78:        dx /= bigger;
        !            79:        dy /= bigger;
        !            80: 
        !            81:        /* check for long range tractor beams */
        !            82:        /****  TEMPORARY CODE == DEBUGGING  ****/
        !            83:        evtime = Now.eventptr[E_LRTB]->date - Now.date;
        !            84: #      ifdef xTRACE
        !            85:        if (Trace)
        !            86:                printf("E.ep = %u, ->evcode = %d, ->date = %.2f, evtime = %.2f\n",
        !            87:                        Now.eventptr[E_LRTB], Now.eventptr[E_LRTB]->evcode,
        !            88:                        Now.eventptr[E_LRTB]->date, evtime);
        !            89: #      endif
        !            90:        if (time > evtime && Etc.nkling < 3)
        !            91:        {
        !            92:                /* then we got a LRTB */
        !            93:                evtime += 0.005;
        !            94:                time = evtime;
        !            95:        }
        !            96:        else
        !            97:                evtime = -1.0e50;
        !            98:        dist = time * speed;
        !            99: 
        !           100:        /* move within quadrant */
        !           101:        Sect[Ship.sectx][Ship.secty] = EMPTY;
        !           102:        x = Ship.sectx + 0.5;
        !           103:        y = Ship.secty + 0.5;
        !           104:        xn = NSECTS * dist * bigger;
        !           105:        n = xn + 0.5;
        !           106: #      ifdef xTRACE
        !           107:        if (Trace)
        !           108:                printf("dx = %.2f, dy = %.2f, xn = %.2f, n = %d\n", dx, dy, xn, n);
        !           109: #      endif
        !           110:        Move.free = 0;
        !           111: 
        !           112:        for (i = 0; i < n; i++)
        !           113:        {
        !           114:                ix = (x += dx);
        !           115:                iy = (y += dy);
        !           116: #              ifdef xTRACE
        !           117:                if (Trace)
        !           118:                        printf("ix = %d, x = %.2f, iy = %d, y = %.2f\n", ix, x, iy, y);
        !           119: #              endif
        !           120:                if (x < 0.0 || y < 0.0 || x >= sectsize || y >= sectsize)
        !           121:                {
        !           122:                        /* enter new quadrant */
        !           123:                        dx = Ship.quadx * NSECTS + Ship.sectx + dx * xn;
        !           124:                        dy = Ship.quady * NSECTS + Ship.secty + dy * xn;
        !           125:                        if (dx < 0.0)
        !           126:                                ix = -1;
        !           127:                        else
        !           128:                                ix = dx + 0.5;
        !           129:                        if (dy < 0.0)
        !           130:                                iy = -1;
        !           131:                        else
        !           132:                                iy = dy + 0.5;
        !           133: #                      ifdef xTRACE
        !           134:                        if (Trace)
        !           135:                                printf("New quad: ix = %d, iy = %d\n", ix, iy);
        !           136: #                      endif
        !           137:                        Ship.sectx = x;
        !           138:                        Ship.secty = y;
        !           139:                        compkldist(0);
        !           140:                        Move.newquad = 2;
        !           141:                        attack(0);
        !           142:                        checkcond();
        !           143:                        Ship.quadx = ix / NSECTS;
        !           144:                        Ship.quady = iy / NSECTS;
        !           145:                        Ship.sectx = ix % NSECTS;
        !           146:                        Ship.secty = iy % NSECTS;
        !           147:                        if (ix < 0 || Ship.quadx >= NQUADS || iy < 0 || Ship.quady >= NQUADS)
        !           148:                                if (!damaged(COMPUTER))
        !           149:                                {
        !           150:                                        dumpme(0);
        !           151:                                }
        !           152:                                else
        !           153:                                        lose(L_NEGENB);
        !           154:                        initquad(0);
        !           155:                        n = 0;
        !           156:                        break;
        !           157:                }
        !           158:                if (Sect[ix][iy] != EMPTY)
        !           159:                {
        !           160:                        /* we just hit something */
        !           161:                        if (!damaged(COMPUTER) && ramflag <= 0)
        !           162:                        {
        !           163:                                ix = x - dx;
        !           164:                                iy = y - dy;
        !           165:                                printf("Computer reports navigation error; %s stopped at %d,%d\n",
        !           166:                                        Ship.shipname, ix, iy);
        !           167:                                Ship.energy -= Param.stopengy * speed;
        !           168:                                break;
        !           169:                        }
        !           170:                        /* test for a black hole */
        !           171:                        if (Sect[ix][iy] == HOLE)
        !           172:                        {
        !           173:                                /* get dumped elsewhere in the galaxy */
        !           174:                                dumpme(1);
        !           175:                                initquad(0);
        !           176:                                n = 0;
        !           177:                                break;
        !           178:                        }
        !           179:                        ram(ix, iy);
        !           180:                        break;
        !           181:                }
        !           182:        }
        !           183:        if (n > 0)
        !           184:        {
        !           185:                dx = Ship.sectx - ix;
        !           186:                dy = Ship.secty - iy;
        !           187:                dist = sqrt(dx * dx + dy * dy) / NSECTS;
        !           188:                time = dist / speed;
        !           189:                if (evtime > time)
        !           190:                        time = evtime;          /* spring the LRTB trap */
        !           191:                Ship.sectx = ix;
        !           192:                Ship.secty = iy;
        !           193:        }
        !           194:        Sect[Ship.sectx][Ship.secty] = Ship.ship;
        !           195:        compkldist(0);
        !           196:        return (time);
        !           197: }

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