low level question to help me with a development project.

for table lookups, the old ecms i'm used to dealing with usually use linear interpolation between cells. so in an imaginary table with 4 columns like 10,20,30,40 and a set of values like 2,3,4,5, a lookup of 10 would give you 2, but a lookup of 35 would give you 4.5.

so functionally if you have a pair of columns x0,x1 and a pair of values y0,y1 you could do something like y0+((x-x0)/(x1-x0))*(y1-y0) to find the value of the column position x

and in a table with both columns and rows, it's just bilinear, so you'd do a lookup against row and column and average it.

my question is do modern ECMs do any more smooth lookups such as cubic/bicubic splines for anything? i have used bicubic spline functions for 3d lookup where my table is low resolution and i know the output should be smooth, so i am wondering if this was used on any of the ECMs we work with.