/** * @brief Gets the distance from the Vec2. * * @usage my_vec:dist() -- Gets length of the vector (distance from origin). * @usage my_vec:dist( your_vec ) -- Gets distance from both vectors (your_vec - my_vec). * * @luaparam v Vector to act as origin. * @luaparam v2 Vector to get distance from, uses origin (0,0) if not set. * @luareturn The distance calculated. * @luafunc dist( v, v2 ) */ static int vectorL_distance( lua_State *L ) { LuaVector *v1, *v2; double dist; /* Get self. */ v1 = luaL_checkvector(L,1); /* Get rest of parameters. */ v2 = NULL; if (lua_gettop(L) > 1) { v2 = luaL_checkvector(L,2); } /* Get distance. */ if (v2 == NULL) dist = vect_odist(&v1->vec); else dist = vect_dist(&v1->vec, &v2->vec); /* Return the distance. */ lua_pushnumber(L, dist); return 1; }
/** * @brief The AI of seeker missiles. * * @param w Weapon to do the thinking. * @param dt Current delta tick. */ static void think_seeker( Weapon* w, const double dt ) { double diff; double vel; Pilot *p; int effect; Vector2d v; double t; if (w->target == w->parent) return; /* no self shooting */ p = pilot_get(w->target); /* no null pilot_nstack */ if (p==NULL) { weapon_setThrust( w, 0. ); weapon_setTurn( w, 0. ); return; } /* Handle by status. */ switch (w->status) { case WEAPON_STATUS_OK: if (w->lockon < 0.) w->status = WEAPON_STATUS_LOCKEDON; break; case WEAPON_STATUS_LOCKEDON: /* Check to see if can get jammed */ if ((p->jam_range != 0.) && /* Target has jammer and weapon is in range */ (vect_dist(&w->solid->pos,&p->solid->pos) < p->jam_range)) { /* Check to see if weapon gets jammed */ if (RNGF() < p->jam_chance - w->outfit->u.amm.resist) { w->status = WEAPON_STATUS_JAMMED; /* Give it a nice random effect */ effect = RNG(0,3); switch (effect) { case 0: /* Stuck in left loop */ weapon_setTurn( w, w->outfit->u.amm.turn ); break; case 1: /* Stuck in right loop */ weapon_setTurn( w, -w->outfit->u.amm.turn ); break; default: /* Blow up. */ w->timer = -1.; break; } } else /* Can't get jammed anymore */ w->status = WEAPON_STATUS_UNJAMMED; } /* Purpose fallthrough */ case WEAPON_STATUS_UNJAMMED: /* Work as expected */ /* Smart seekers take into account ship velocity. */ if (w->outfit->u.amm.ai == 2) { /* Calculate time to reach target. */ vect_cset( &v, p->solid->pos.x - w->solid->pos.x, p->solid->pos.y - w->solid->pos.y ); t = vect_odist( &v ) / w->outfit->u.amm.speed; /* Calculate target's movement. */ vect_cset( &v, v.x + t*(p->solid->vel.x - w->solid->vel.x), v.y + t*(p->solid->vel.y - w->solid->vel.y) ); /* Get the angle now. */ diff = angle_diff(w->solid->dir, VANGLE(v) ); } /* Other seekers are stupid. */ else { diff = angle_diff(w->solid->dir, /* Get angle to target pos */ vect_angle(&w->solid->pos, &p->solid->pos)); } /* Set turn. */ weapon_setTurn( w, CLAMP( -w->outfit->u.amm.turn, w->outfit->u.amm.turn, 10 * diff * w->outfit->u.amm.turn )); break; case WEAPON_STATUS_JAMMED: /* Continue doing whatever */ /* Do nothing, dir_vel should be set already if needed */ break; default: WARN("Unknown weapon status for '%s'", w->outfit->name); break; } /* Limit speed here */ vel = MIN(w->outfit->u.amm.speed, VMOD(w->solid->vel) + w->outfit->u.amm.thrust*dt); vect_pset( &w->solid->vel, vel, w->solid->dir ); /*limit_speed( &w->solid->vel, w->outfit->u.amm.speed, dt );*/ }