How quantization works

[huonghld]

Assume a vertex has a position (x, y, z). Does Draco quantize each coordinate x, y, z separately or does it combine (x, y, z) into a quantized value? And how many quantized values should it be after quantization? I checked my result, with qp=1, number of new vertices (let's call N) = 4 qp = 2, N=21 qp = 3, N = 217 qp = 4, N= 944 qp = 5, N = 1234

Should not the number of quantized vertices = 2^qp?