| 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 | } |