TypedArrays as mesh3d attributes

[dy]

Sometimes 3d data, like simplicial-complex, has TypedArray format, eg. Float32Array for positions and Uint32Array for cell indices:

  // positions = Float32Array
  // cells = Uint32Array

  Plotly.plot(document.body, [{
    "x": positions.filter((p, i) => !(i % 3)),
    "y": positions.filter((p, i) => !((i-1) % 3)),
    "z": positions.filter((p, i) => !((i-2) % 3)),
    "i": indices.filter((p, i) => !(i % 3)),
    "j": indices.filter((p, i) => !((i-1) % 3)),
    "k": indices.filter((p, i) => !((i-2) % 3)),
  }])

Would be nice for plotly to be able to deal with TypedArrays and not force users cast data to exact datatype.

[etpinard]

duplicate of #860