stuffiwillneveruse.js

function tobuffer(points){
  var length = points.length;

  var len = length * 4;

  var buffer = new ArrayBuffer(len * 4);

  var lats = new Float32Array(buffer, 0, len/4);
  var lons = new Float32Array(buffer, len, len/4);
  var alts = new Float32Array(buffer, len*2, len/4);
  var refs = new Uint32Array (buffer, len*3, len/4);

  points.forEach(function(p, i){
    lats[i] = p[0];
    lons[i] = p[1];
    alts[i] = p[2];
    refs[i] = p[3];
  })

  return {
    data: buffer,
    length: length,

    lats: lats,
    lons: lons,
    alts: alts,
    refs: refs
  }
}

function combine(buffers){

  // point length
  var length = buffers.reduce(function(l, b){
    return l + b.length;
  }, 0);

  // byte length
  var len = length * 4;

  var buffer = new ArrayBuffer(len * 4);

  var lats = new Float32Array(buffer, 0, len/4);
  var lons = new Float32Array(buffer, len, len/4);
  var alts = new Float32Array(buffer, len*2, len/4);
  var refs = new Uint32Array (buffer, len*3, len/4);

  buffers.reduce(function(off, b){

    lats.set(b.lats, off)
    lons.set(b.lons, off)
    alts.set(b.alts, off)
    refs.set(b.refs, off)

    return off + b.length;
  }, 0)

  return {
    data: buffer,
    length: length,

    lats: lats,
    lons: lons,
    alts: alts,
    refs: refs
  }

}


b = tobuffer([
  [.1,20,3,4],
  [.2,20,4,4.4]
])

console.log(b);
console.log(b.lats);
console.log(b.lons);
console.log(b.alts);
console.log(b.refs);

var b2 = tobuffer([
  [.3,21,5,4.2],
  [.4,23,6,4]
])

console.log(b2);
console.log(b2.lats);
console.log(b2.lons);
console.log(b2.alts);
console.log(b2.refs);

var b3 = tobuffer([
  [.5,24,7,4.2],
  [.6,25,8,400]
])

console.log("combining");
var b4 = combine([b, b2, b3]);

console.log(b4);
console.log(b4.lats);
console.log(b4.lons);
console.log(b4.alts);
console.log(b4.refs);