fourtyEightChurner.js

// Helper Function to generate 768 points, as supplied by frandss
function testData(){
    var output = [];
	for (var x = 0; x < 768; x ++) output.push(x);
	return output
}

function fourtyEightChurner(array, length, current) {
  if(current > (length - 48)) return 0;

  subArray = array.slice(current, current + 48);
  for(var i = current, j = 47; i < current + 48; i++, j--) array[i] = subArray[j];

  return fourtyEightChurner(array, length, current + 48 + 48);
}

// testing with '48' (magic number)
var test1 = testData();
fourtyEightChurner(test1, test1.length, 49);
console.log(test1);