bool TTetrahedron::IsInner(const TPoint& P) const {
TVector N, U1(X1, X2), U2(X1, X3), U3(X1, X4), U4(X2, X3), U5(X2, X4), U6(X2, X1);
TVector Up1(X1, P), Up2(X2, P);
N = Cross(U1, U2); //X4 is on opposite side of plain X1,X2,X3 than P
if (Dot(N, U3) * Dot(N, Up1) < 0) {
return false;
}
N = Cross(U1, U3); //X3 x P
if (Dot(N, U2) * Dot(N, Up1) < 0) {
return false;
}
N = Cross(U2, U3); //X2 x P
if (Dot(N, U1) * Dot(N, Up1) < 0) {
return false;
}
N = Cross(U4, U5); //X1 x P
if (Dot(N, U6) * Dot(N, Up2) < 0) {
return false;
}
return true;
}
/*
* E4. [Let people out, in.] If anyone in the ELEVATOR list has OUT == FLOOR, send
* the user of this type who has most recently entered immediately to step U6,
* wait 25 units, and repeat step E4. If no such users exist, but QUEUE[FLOOR]
* is not empty, send the front person of that queue immediately to step U5
* instead of U4, wait 25 units, and repeat step E4. But if QUEUE[FLOOR]
* is empty, set D1 <-- 0, make D3 nonzero, and wait for some other activity
* to initiate further action. (Step E5 will send us to E6, or step U2 will
* restart E4.)
*/
void E4(void)
{
USER_NODE * p = ELEVATOR.ER;
for (; p != &ELEVATOR; p = p->ER) {
int out = p->uinfo->OUT;
if (out == FLOOR) {
xlog(LOG_E, "E4(). %s is sent to U6().\n",
p->uinfo->name);
U6(p->uinfo);
in_WAIT(TIME + 25, E4, NO_ARG); /** empty the elevator */
return;
}
}
p = QUEUE[FLOOR].ER;
if (p != &QUEUE[FLOOR]) { /** QUEUE[FLOOR] is not empty */
xlog(LOG_E, "E4(). %s is sent to U5().\n",
p->uinfo->name);
out_WAIT(U4, p->uinfo); /** fortunately the elevator comes */
/** the sequence of these two lines cannot be exchanged, because
* it should be guarranteed that ``E5'' in this line (called in U5):
* in_WAIT(TIME + 25, E5, NO_ARG);
* should be scheduled after ``E4'' of in the following in_WAIT():
*/
in_WAIT(TIME + 25, E4, NO_ARG); /** fill the elevator */
U5(p->uinfo);
}
else {
D1 = 0;
D3 = 1;
xlog(LOG_E, "E4(). Nobody is here. "
"wait for some other activity to initiate further action\n");
return;
}
}
