/* $NetBSD: move.c,v 1.11 2011/07/03 06:44:01 mrg Exp $ */
/*
* Copyright (c) 1980, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)move.c 8.1 (Berkeley) 5/31/93";
#else
__RCSID("$NetBSD: move.c,v 1.11 2011/07/03 06:44:01 mrg Exp $");
#endif
#endif /* not lint */
#include <stdio.h>
#include <math.h>
#include <float.h>
#include "trek.h"
/*
** Move Under Warp or Impulse Power
**
** `Ramflag' is set if we are to be allowed to ram stars,
** Klingons, etc. This is passed from warp(), which gets it from
** either play() or ram(). Course is the course (0 -> 360) at
** which we want to move. `Speed' is the speed we
** want to go, and `time' is the expected time. It
** can get cut short if a long range tractor beam is to occur. We
** cut short the move so that the user doesn't get docked time and
** energy for distance which he didn't travel.
**
** We check the course through the current quadrant to see that he
** doesn't run into anything. After that, though, space sort of
** bends around him. Note that this puts us in the awkward posi-
** tion of being able to be dropped into a sector which is com-
** pletely surrounded by stars. Oh Well.
**
** If the SINS (Space Inertial Navigation System) is out, we ran-
** domize the course accordingly before ever starting to move.
** We will still move in a straight line.
**
** Note that if your computer is out, you ram things anyway. In
** other words, if your computer and sins are both out, you're in
** potentially very bad shape.
**
** Klingons get a chance to zap you as you leave the quadrant.
** By the way, they also try to follow you (heh heh).
**
** Return value is the actual amount of time used.
**
**
** Uses trace flag 4.
*/
double
move(int ramflag, int course, double time, double speed)
{
double angle;
double x, y, dx, dy;
int ix = 0, iy = 0;
double bigger;
int n;
int i;
double dist;
double sectsize;
double xn;
double evtime;
#ifdef xTRACE
if (Trace)
printf("move: ramflag %d course %d time %.2f speed %.2f\n",
ramflag, course, time, speed);
#endif
sectsize = NSECTS;
/* initialize delta factors for move */
angle = course * 0.0174532925;
if (damaged(SINS))
angle += Param.navigcrud[1] * (franf() - 0.5);
else
if (Ship.sinsbad)
angle += Param.navigcrud[0] * (franf() - 0.5);
dx = -cos(angle);
dy = sin(angle);
bigger = fabs(dx);
dist = fabs(dy);
if (dist > bigger)
bigger = dist;
dx /= bigger;
dy /= bigger;
/* check for long range tractor beams */
/**** TEMPORARY CODE == DEBUGGING ****/
evtime = Now.eventptr[E_LRTB]->date - Now.date;
#ifdef xTRACE
if (Trace)
printf("E.ep = %p, ->evcode = %d, ->date = %.2f, "
"evtime = %.2f\n",
Now.eventptr[E_LRTB], Now.eventptr[E_LRTB]->evcode,
Now.eventptr[E_LRTB]->date, evtime);
#endif
if (time > evtime && Etc.nkling < 3) {
/* then we got a LRTB */
evtime += 0.005;
time = evtime;
} else
evtime = DBL_MIN;
dist = time * speed;
/* move within quadrant */
Sect[Ship.sectx][Ship.secty] = EMPTY;
x = Ship.sectx + 0.5;
y = Ship.secty + 0.5;
xn = NSECTS * dist * bigger;
n = xn + 0.5;
#ifdef xTRACE
if (Trace)
printf("dx = %.2f, dy = %.2f, xn = %.2f, n = %d\n",
dx, dy, xn, n);
#endif
Move.free = 0;
for (i = 0; i < n; i++) {
ix = (x += dx);
iy = (y += dy);
#ifdef xTRACE
if (Trace)
printf("ix = %d, x = %.2f, iy = %d, y = %.2f\n",
ix, x, iy, y);
#endif
if (x < 0.0 || y < 0.0 || x >= sectsize || y >= sectsize) {
/* enter new quadrant */
dx = Ship.quadx * NSECTS + Ship.sectx + dx * xn;
dy = Ship.quady * NSECTS + Ship.secty + dy * xn;
if (dx < 0.0)
ix = -1;
else
ix = dx + 0.5;
if (dy < 0.0)
iy = -1;
else
iy = dy + 0.5;
#ifdef xTRACE
if (Trace)
printf("New quad: ix = %d, iy = %d\n", ix, iy);
#endif
Ship.sectx = x;
Ship.secty = y;
compkldist(0);
Move.newquad = 2;
attack(0);
checkcond();
Ship.quadx = ix / NSECTS;
Ship.quady = iy / NSECTS;
Ship.sectx = ix % NSECTS;
Ship.secty = iy % NSECTS;
if (ix < 0 || Ship.quadx >= NQUADS || iy < 0 ||
Ship.quady >= NQUADS) {
if (!damaged(COMPUTER)) {
dumpme(0);
} else
lose(L_NEGENB);
}
initquad(0);
n = 0;
break;
}
if (Sect[ix][iy] != EMPTY) {
/* we just hit something */
if (!damaged(COMPUTER) && ramflag <= 0) {
ix = x - dx;
iy = y - dy;
printf("Computer reports navigation error; "
"%s stopped at %d,%d\n",
Ship.shipname, ix, iy);
Ship.energy -= Param.stopengy * speed;
break;
}
/* test for a black hole */
if (Sect[ix][iy] == HOLE) {
/* get dumped elsewhere in the galaxy */
dumpme(1);
initquad(0);
n = 0;
break;
}
ram(ix, iy);
break;
}
}
if (n > 0) {
dx = Ship.sectx - ix;
dy = Ship.secty - iy;
dist = sqrt(dx * dx + dy * dy) / NSECTS;
time = dist / speed;
if (evtime > time) {
/* spring the LRTB trap */
time = evtime;
}
Ship.sectx = ix;
Ship.secty = iy;
}
Sect[Ship.sectx][Ship.secty] = Ship.ship;
compkldist(0);
return (time);
}