mdw@git.distorted.org.uk Git - newkind/blob - pilot.c

   1 /*
   2  * Elite - The New Kind.
   3  *
   4  * Reverse engineered from the BBC disk version of Elite.
   5  * Additional material by C.J.Pinder.
   6  *
   7  * The original Elite code is (C) I.Bell & D.Braben 1984.
   8  * This version re-engineered in C by C.J.Pinder 1999-2001.
   9  *
  10  * email: <christian@newkind.co.uk>
  11  *
  12  *
  13  */
  14
  15 /*
  16  * pilot.c
  17  *
  18  * The auto-pilot code.  Used for docking computers and for
  19  * flying other ships to and from the space station.
  20  */
  21
  22 /*
  23  * In the original Elite this code was mixed in with the tactics routines.
  24  * I have split it out to make it more understandable and easier to maintain.
  25  */
  26
  27
  28 #include <math.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31
  32 #include "config.h"
  33 #include "gfx.h"
  34 #include "elite.h"
  35 #include "vector.h"
  36 #include "main.h"
  37 #include "space.h"
  38 #include "sound.h"
  39
  40
  41 /*
  42  * Fly to a given point in space.
  43  */
  44
  45 void fly_to_vector (struct univ_object *ship, Vector vec)
  46 {
  47         Vector nvec;
  48         double direction;
  49         double dir;
  50         int rat;
  51         double rat2;
  52         double cnt2;
  53
  54         rat = 3;
  55         rat2 = 0.1666;
  56         cnt2 = 0.8055;
  57
  58         nvec = unit_vector(&vec);
  59         direction = vector_dot_product (&nvec, &ship->rotmat[2]);
  60
  61         if (direction < -0.6666)
  62                 rat2 = 0;
  63
  64         dir = vector_dot_product (&nvec, &ship->rotmat[1]);
  65
  66         if (direction < -0.861)
  67         {
  68                 ship->rotx = (dir < 0) ? 7 : -7;
  69                 ship->rotz = 0;
  70                 return;
  71         }
  72
  73         ship->rotx = 0;
  74
  75         if ((fabs(dir) * 2) >= rat2)
  76         {
  77                 ship->rotx = (dir < 0) ? rat : -rat;
  78         }
  79
  80         if (abs(ship->rotz) < 16)
  81         {
  82                 dir = vector_dot_product (&nvec, &ship->rotmat[0]);
  83
  84                 ship->rotz = 0;
  85
  86                 if ((fabs(dir) * 2) >= rat2)
  87                 {
  88                         ship->rotz = (dir < 0) ? rat : -rat;
  89
  90                         if (ship->rotx < 0)
  91                                 ship->rotz = -ship->rotz;
  92                 }
  93         }
  94
  95         if (direction <= -0.167)
  96         {
  97                 ship->acceleration = -1;
  98                 return;
  99         }
 100
 101         if (direction >= cnt2)
 102         {
 103                 ship->acceleration = 3;
 104                 return;
 105         }
 106 }
 107
 108
 109
 110 /*
 111  * Fly towards the planet.
 112  */
 113
 114 void fly_to_planet (struct univ_object *ship)
 115 {
 116         Vector vec;
 117
 118         vec.x = universe[0].location.x - ship->location.x;
 119         vec.y = universe[0].location.y - ship->location.y;
 120         vec.z = universe[0].location.z - ship->location.z;
 121
 122         fly_to_vector (ship, vec);
 123 }
 124
 125
 126 /*
 127  * Fly to a point in front of the station docking bay.
 128  * Done prior to the final stage of docking.
 129  */
 130
 131
 132 void fly_to_station_front (struct univ_object *ship)
 133 {
 134         Vector vec;
 135
 136         vec.x = universe[1].location.x - ship->location.x;
 137         vec.y = universe[1].location.y - ship->location.y;
 138         vec.z = universe[1].location.z - ship->location.z;
 139
 140         vec.x += universe[1].rotmat[2].x * 768;
 141         vec.y += universe[1].rotmat[2].y * 768;
 142         vec.z += universe[1].rotmat[2].z * 768;
 143
 144         fly_to_vector (ship, vec);
 145 }
 146
 147
 148 /*
 149  * Fly towards the space station.
 150  */
 151
 152 void fly_to_station (struct univ_object *ship)
 153 {
 154         Vector vec;
 155
 156         vec.x = universe[1].location.x - ship->location.x;
 157         vec.y = universe[1].location.y - ship->location.y;
 158         vec.z = universe[1].location.z - ship->location.z;
 159
 160         fly_to_vector (ship, vec);
 161 }
 162
 163
 164 /*
 165  * Final stage of docking.
 166  * Fly into the docking bay.
 167  */
 168
 169 void fly_to_docking_bay (struct univ_object *ship)
 170 {
 171         Vector diff;
 172         Vector vec;
 173         double dir;
 174
 175         diff.x = ship->location.x - universe[1].location.x;
 176         diff.y = ship->location.y - universe[1].location.y;
 177         diff.z = ship->location.z - universe[1].location.z;
 178
 179         vec = unit_vector (&diff);
 180
 181         ship->rotx = 0;
 182
 183         if (ship->type < 0)
 184         {
 185                 ship->rotz = 1;
 186                 if (((vec.x >= 0) && (vec.y >= 0)) ||
 187                          ((vec.x < 0) && (vec.y < 0)))
 188                 {
 189                         ship->rotz = -ship->rotz;
 190                 }
 191
 192                 if (fabs(vec.x) >= 0.0625)
 193                 {
 194                         ship->acceleration = 0;
 195                         ship->velocity = 1;
 196                         return;
 197                 }
 198
 199                 if (fabs(vec.y) > 0.002436)
 200                         ship->rotx = (vec.y < 0) ? -1 : 1;
 201
 202                 if (fabs(vec.y) >= 0.0625)
 203                 {
 204                          ship->acceleration = 0;
 205                          ship->velocity = 1;
 206                          return;
 207                 }
 208         }
 209
 210         ship->rotz = 0;
 211
 212         dir = vector_dot_product (&ship->rotmat[0], &universe[1].rotmat[1]);
 213
 214         if (fabs(dir) >= 0.9166)
 215         {
 216                 ship->acceleration++;
 217                 ship->rotz = 127;
 218                 return;
 219         }
 220
 221         ship->acceleration = 0;
 222         ship->rotz = 0;
 223 }
 224
 225
 226 /*
 227  * Fly a ship to the planet or to the space station and dock it.
 228  */
 229
 230 void auto_pilot_ship (struct univ_object *ship)
 231 {
 232         Vector diff;
 233         Vector vec;
 234         double dist;
 235         double dir;
 236
 237         if ((ship->flags & FLG_FLY_TO_PLANET) ||
 238                 ((ship_count[SHIP_CORIOLIS] == 0) && (ship_count[SHIP_DODEC] == 0)))
 239         {
 240                 fly_to_planet (ship);
 241                 return;
 242         }
 243
 244         diff.x = ship->location.x - universe[1].location.x;
 245         diff.y = ship->location.y - universe[1].location.y;
 246         diff.z = ship->location.z - universe[1].location.z;
 247
 248         dist = sqrt (diff.x * diff.x + diff.y * diff.y + diff.z * diff.z);
 249
 250         if (dist < 160)
 251         {
 252                 ship->flags |= FLG_REMOVE;              // Ship has docked.
 253                 return;
 254         }
 255
 256         vec = unit_vector (&diff);
 257         dir = vector_dot_product (&universe[1].rotmat[2], &vec);
 258
 259         if (dir < 0.9722)
 260         {
 261                 fly_to_station_front (ship);
 262                 return;
 263         }
 264
 265         dir = vector_dot_product (&ship->rotmat[2], &vec);
 266
 267         if (dir < -0.9444)
 268         {
 269                 fly_to_docking_bay (ship);
 270                 return;
 271         }
 272
 273         fly_to_station (ship);
 274 }
 275
 276
 277 void engage_auto_pilot (void)
 278 {
 279         if (auto_pilot || witchspace || hyper_ready)
 280                 return;
 281
 282         auto_pilot = 1;
 283         snd_play_midi (SND_BLUE_DANUBE, 1);
 284 }
 285
 286
 287 void disengage_auto_pilot (void)
 288 {
 289         if (auto_pilot)
 290         {
 291                 auto_pilot = 0;
 292                 snd_stop_midi();
 293         }
 294 }