3d geometry: how to interpolate a matrix

Question

i store the position of an object in 3d space in a 4by4 transformation matrix. now in order to move the object from the position stored in matrix A to the position stored in

Answer 1

Source code for transformation matrix interpolation, with an unrestrictive license, can be found in the WebKit project; see the functions called 'blend', which create an interpolated matrix:

for general 4 x 4 matrices

for six-element affine transforms used in 2D graphics

All the files, including headers, can be found in the enclosing directory.

BUT I have just tried the 2D affine code and it doesn't preserve the centre of rotation when interpolating between rotations. So I am now not so sure that it is useful.