/**
* Get the appropriate offset (always > 0) of the internal rotor core
* with respect to global 'A' position
* This offset is influenced by
* i) the ring setting (which stays the same for a given ciphertext, and
* ii) the window value (which updates every time the enigma ticks)
* @param ringSetting
* @param windowSetting
* @param slot
* @return
*/
public static int GetOffsetRotorInternal(RingSetting ringSetting, WindowSetting windowSetting, int slot)
{
//for easy intuition, we call the global 'A' position the sea level
int dispRingAboveSea; //displacement of Ring with respect to global 'A' position
int dispRotorInternalWrtRing;
int dispRotorInternalAboveSea; //always > 0, expressed in mod26
dispRingAboveSea = 'A' - windowSetting.getWindowValue(slot); //if window shows 'C', disp = -2
dispRotorInternalWrtRing = ringSetting.ringOffset(slot); //offset = 4 means internal A is locked to ring's E
dispRotorInternalAboveSea = (dispRingAboveSea + dispRotorInternalWrtRing + 26) % 26;
return(dispRotorInternalAboveSea);
}
