spiral pattern code

/*-----( Import needed libraries )-----*/
#include <AccelStepper.h>
/*-----( Declare Constants and Pin Numbers )-----*/
#define FULLSTEP 4
#define HALFSTEP 8
// motor pins
#define motorPin1  4     // Blue   - 28BYJ48 pin 1
#define motorPin2  5     // Pink   - 28BYJ48 pin 2
#define motorPin3  6     // Yellow - 28BYJ48 pin 3
#define motorPin4  7     // Orange - 28BYJ48 pin 4
                        // Red    - 28BYJ48 pin 5 (VCC)
#define motorPin5  8     // Blue   - 28BYJ48 pin 1
#define motorPin6  9     // Pink   - 28BYJ48 pin 2
#define motorPin7  10    // Yellow - 28BYJ48 pin 3
#define motorPin8  11    // Orange - 28BYJ48 pin 4
                        // Red    - 28BYJ48 pin 5 (VCC)
/*-----( Declare objects )-----*/
// NOTE: The sequence 1-3-2-4 is required for proper sequencing of 28BYJ48
AccelStepper stepper1(HALFSTEP, motorPin1, motorPin3, motorPin2, motorPin4);
AccelStepper stepper2(HALFSTEP, motorPin5, motorPin7, motorPin6, motorPin8);

void setup()   /****** SETUP: RUNS ONCE ******/
{
  stepper1.setMaxSpeed(1000.0);
  stepper1.setAcceleration(50.0);
  stepper1.setSpeed(200);
  stepper1.moveTo(4048);  // 2048 = 1 revolution
  stepper2.setMaxSpeed(1000.0);
  stepper2.setAcceleration(50.0);
  stepper2.setSpeed(200);
  stepper2.moveTo(-2448);  // 2048 = 1 revolution minus 400 to make it asymetric asymetric
}//--(end setup )---
void loop()   /****** LOOP: RUNS CONSTANTLY ******/
{
  //Change direction at the limits
  if (stepper1.distanceToGo() == 0)
    stepper1.moveTo(-stepper1.currentPosition());
    if (stepper2.distanceToGo() == 0)
    stepper2.moveTo(-stepper2.currentPosition());
  stepper1.run();
  stepper2.run();
}//--(end main loop )---