HDD rotary encoder with interrupts!

I ripped apart a few of  the many old IDE HDD siting around for the BLDC motors that they contain to create a rotary encoder device.

something like:

The circuit building turned out pretty well. The HDD had a BLDC with 3 pins(whye windings) so i used the following scheme, but only the first two Op-Amps. One of the windings(pin) is a reference to the other two windings and used to determine direction. Signal 1 and 2 go to digital ports 2 and 3 on the Arduino for a 3 pin motor.

VCC(5v) and GND also need to be connected.

The coding side was, of course, an adventure; I first attempted it all on my own with interrupts(i understand them finally :)) and it worked OK, but could be improved a little. These are the waveforms of the two pins that the Arduino relies on to determine the direction the motor is turning.

Code that someone posted that is more efficient, but i don't understand: Reading Encoder Gray code 2 bit

Pics:

Encoder and needed LM324N IC. Also the joystick breakout cable is there.

My Code:

#define EncPinA 2
#define EncPinB 3
volatile unsigned int EncPos = 0;
void setup()
{
  pinMode(EncPinA, INPUT);
  digitalWrite(EncPinA, HIGH);

  pinMode(EncPinB, INPUT);
  digitalWrite(EncPinB, HIGH);

  attachInterrupt(0, EncA, CHANGE);  // encoder pin on interrupt 0 (pin 2)
  attachInterrupt(1, EncB, CHANGE);  // encoder pin on interrupt 1 (pin 3)
  Serial.begin (115200);
}
void loop()
{
  //FREE for a MIDI interface(turntables?) or something!
}
void EncA(){
  // look for a low-to-high on pin A
  if (digitalRead(EncPinA) == HIGH) {
    // check pin B to see which way encoder is turning
    if (digitalRead(EncPinB) == LOW) {
      EncPos = EncPos - 1;         // CW
    }
    else {
      EncPos = EncPos + 1;         // CCW
    }
  }
  else   // must be a high-to-low edge on pin A                                    
  {
    // check pin B to see which way encoder is turning
    if (digitalRead(EncPinB) == HIGH) {
      EncPos = EncPos - 1;          // CW
    }
    else {
      EncPos = EncPos + 1;          // CCW
    }
  }
  Serial.println (EncPos, DEC);        
  // use for debugging - remember to comment out
}
void EncB(){
  // look for a low-to-high on pin B
  if (digitalRead(EncPinB) == HIGH) {
    // check pin A to see which way encoder is turning
    if (digitalRead(EncPinA) == HIGH) {
      EncPos = EncPos - 1;         // CW
    }
    else {
      EncPos = EncPos + 1;         // CCW
    }
  }
  // Look for a high-to-low on pin B
  else {
    // check pin B to see which way encoder is turning
    if (digitalRead(EncPinA) == LOW) {
      EncPos = EncPos - 1;          // CW
    }
    else {
      EncPos = EncPos + 1;          // CCW
    }
  }
}