direct manipulation port for DUE

Official Hardware Mega Due
3

I have a program for Arduino Mini 16MHz, and I would use it for Arduino Due.
Mini has a digital port 2-13, but DUE has 22-53.
I need 22pin for encoder A and 23pin for encoder B for out 52pin - pulse and 53pin - step.
I do not know how i can write this code functioning for DUE.

#define encoder_a 2 //need for due 22pin
#define encoder_b 3 //need for due 23pin
#define motor_step 4 //need for due 52pin
#define motor_direction 5 //need for due 53pin

#include <delay.h>
volatile long motor_position, encoder;

byte inputA;
byte inputB;

void setup () {
  //set up the various outputs
  pinMode(motor_step, OUTPUT);
  pinMode(motor_direction, OUTPUT);

  // then the encoder inputs
  pinMode(encoder_a, INPUT);
  pinMode(encoder_b, INPUT);

  // enable pullup as we are using an open collector encoder
  digitalWrite(encoder_a, HIGH); 
  digitalWrite(encoder_b, HIGH); 

  // encoder pin on interrupt 0 (pin 2)
  attachInterrupt(0, encoderPinChangeA, CHANGE);
  // encoder pin on interrupt 1 (pin 3)
  attachInterrupt(1, encoderPinChangeB, CHANGE);
  encoder = 0; //reseet the encoder position to 0
}

void loop() {
  //do stuff dependent on encoder position here
  //such as move a stepper motor to match encoder position
  //if you want to make it 1:1 ensure the encoder res matches the motor res by dividing/multiplying
  if (encoder > 0) {
    //digitalWrite(motor_direction, HIGH);// move stepper in reverse
    PORTD = PORTD | 0b00100000;
    //digitalWrite(motor_step, HIGH);
    PORTD = PORTD | 0b00010000;

    //digitalWrite(motor_step, LOW);
    PORTD = PORTD & 0b11101111;
    delayMicroseconds(600); //_delay_us(200); //modify to alter speed
    motor_position++;
    encoder = 0; //encoder--;
  }
  else if (encoder < 0) {
    //digitalWrite (motor_direction, LOW); //move stepper forward
    PORTD = PORTD & 0b11011111; 
    //digitalWrite (motor_step, HIGH);
    PORTD = PORTD | 0b00010000;
    //digitalWrite (motor_step, LOW);
    PORTD = PORTD & 0b11101111;
    delayMicroseconds(600); //_delay_us(200); //modify to alter speed
    motor_position--;
    encoder = 0; //encoder++;
  }
}

void encoderPinChangeA() {
  inputA = (PIND & 0b00000100) >>2; // result is 0b00000001 if input is high, 0b00000000 if input is low.
  inputB = (PIND & 0b00001000) >>3; //result is 0b00000001 if input is high, 0b00000000 if input is low.

    //if (digitalRead(encoder_a)==digitalRead(encoder_b)) {
  if (inputA == inputB){
    encoder--;
  }
  else{
    encoder++;
  }
}

void encoderPinChangeB() {
  inputA = (PIND & 0b00000100) >>2; // result is 0b00000001 if input is high, 0b00000000 if input is low.
  inputB = (PIND & 0b00001000) >>3; // result is 0b00000001 if input is high, 0b00000000 if input is low.
    //if (digitalRead(encoder_a) != digitalRead(encoder_b)) {
  if (inputA != inputB){
    encoder--;
  }
  else {
    encoder++;
  }
}