cairo:matrix-multiply (matrix a b)

matrix -- a cairo:matrix-t instance for the result
a -- a cairo:matrix-t instance
b -- a cairo:matrix-t instance

The cairo:matrix-t instance with the result.

Multiplies the affine transformations in a and b together, The effect of the resulting transformation is to first apply the transformation in a to the coordinates and then apply the transformation in b to the coordinates.

It is allowable for matrix to be identical to either a or b.