A little refactoring

#include <AFMotor.h>

AF_Stepper motorL(200, 1);  // Left Motor, M1 & M2
AF_Stepper motorR(200, 2);  // Right Motor, M3 & M4
// Forward is Up on both motors.

// button holds the sketch in setup, until pressed. This stops the
// motors from moving under USB power while uploading.
const int button = 2;
const int LED = 14; // LED indicates end of sketch

int progress = 0; // iteration/cycle
// uses the "progress" to look into the array, and present the switch
// progress, so it knows what basic to do.
int current = 0;
const int pixelsteps = 32; // size of a pixel, in steps
//pixelsteps needs to be 2,4,6,8,16,32,or 64 else will skew image...

// this basic and format works
// dont fiddle with it!
int  basic[]{

5,5,7,3,
5,4,4,5,7,5,
5,4,3,3,4,5,7,7,
5,4,3,2,2,3,4,5,7,9,
5,4,3,2,1,1,2,3,4,5,7,11,
5,4,3,2,1,1,1,1,2,3,4,5,7,13,
5,4,3,2,1,1,1,1,1,1,2,3,4,5,7,15,
5,4,3,2,1,1,1,1,1,1,1,1,1,3,4,5,7,17,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,19,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,21,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,23,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,25,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,27,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,29,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,31,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,31,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,31,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,31,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,31,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,31,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,31,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,31,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,31,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,31,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,31,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,31,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,31,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,31,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,31,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,29,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,27,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,25,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,23,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,21,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,19,
5,4,3,2,1,1,1,1,1,1,1,1,1,1,2,3,4,5,7,17,
5,4,3,2,1,1,1,1,1,1,1,1,2,3,4,5,7,15,
8

};// end of basic
/* Comma separate pixels or instructions: 1 is none, 2 is lightest,
 * 6 is Darkest.
 7 is return while the number following any 7 is the distance to return
 *  in pixels,
 8 is End. pixels are currently squares of 40 steps
 **********************************************************************/

void setup() {

  pinMode (LED, OUTPUT);
  pinMode (button, INPUT);

  motorL.setSpeed(50);  // 10 rpm
  motorR.setSpeed(50);  // 10 rpm

  //hold
  while (digitalRead (button) == HIGH){
    // stops script. Its waiting for a button press (LOW on "button")
  }
}


void loop() {
  current = basic[progress]; // ****************************************

  switch (current) {
    case 1: // nil, straight to next pixel
      motorL.step(pixelsteps , FORWARD, INTERLEAVE);
    break;

  case 2: // lightest, 1 step
    pixel(2);
    break;

  case 3: //  light, 2 steps
    pixel(4);
    break;

  case 4: // Medium, 4 steps
    pixel(8);
    break;

  case 5: // Darker, 10 steps
    pixel(16);
    break;

  case 6: // Darkest 20 steps
    pixel(32);
    break;

  case 7: // Carriage Return.
    motorR.step((pixelsteps +1), FORWARD, INTERLEAVE);
    ++progress;
    current = basic[progress]; // **************************************
    //The number following any 7 in the array is used only to tell it
    // how far to return,
    motorL.step((current * pixelsteps), BACKWARD, INTERLEAVE);
    //and is then discarded. It is not a case, nor a shade.
    motorR.step(1, FORWARD, INTERLEAVE);
    break;

  // Lights the LED and waits for a button press as a method of stop
  case 8:
    digitalWrite (LED, HIGH);
    //hold
    while (digitalRead (button) == HIGH){
      // stops script. Its waiting for a button press (LOW on "button")
    }
    break;
  }

  ++progress; // move to the next instruction in the array!
}

void pixel(int shade) {
    for (int i = 0; i < (shade / 2); ++i) {
      motorL.step((pixelsteps / shade), FORWARD, INTERLEAVE);
      motorR.step((pixelsteps - 2), FORWARD, INTERLEAVE);
      motorL.step((pixelsteps / shade), FORWARD, INTERLEAVE);
      motorR.step((pixelsteps - 2), BACKWARD, INTERLEAVE);
    }
}