linear interpolation：
bilinear interpolation = 2次linear interpolation + 1 次linear interpolation = 3 次 linear interpolation
红点→蓝点 →绿点
trilinear interpolation = 2次bilinear interpolation + 1 次linear interpolation
= 2 * 3次 linear interpolation + 1 次linear interpolation = 7次linear interpolation
黑点→蓝点→绿点→红点
同理quadlinear interpolation = 2次triinear interpolation + 1 次linear interpolation
= 2 * 7次linear interpolation + 1 次linear interpolation = 15次linear interpolation
trilinear interpolation contain （int）(7 linear interpolation / 3) = 2 bilinear interpolation
quadlinear interpolation contain （int）(15 linear interpolation / 3) = 5 bilinear interpolation