I’m attempting to create the composite transformation matrix using individual 4×4 matrices derived from the values of the following properties:

order

perspective

rotate

scale

transform

transform-origin

The specification describes the order to follow when computing the transformation matrix:

The transformation matrix is computed from the transform,
transform-origin, translate, rotate, scale, and offset properties as
follows:

1. Start with the identity matrix.

2. Translate by the computed X, Y, and Z values of transform-origin.

3. Translate by the computed X, Y, and Z values of translate.

4. Rotate by the computed <angle> about the specified axis of rotate.

5. Scale by the computed X, Y, and Z values of scale.

6. Translate and rotate by the transform specified by offset.

7. Multiply by each of the transform functions in transform from left to
   right.

8. Translate by the negated computed X, Y and Z values of
   transform-origin.

I have two questions about this:

1. Why doesn’t the specification mention perspective? Isn’t that also part of the composite transformation? If so, where would it fall in the order?

2. How would I convert the offset value into a 4×4 matrix to multiply with the others? I’ve been able to convert all the other values to 4×4 matrices, but I’m not sure what to do about this. offset is shorthand for five values. I’m not sure how to combine these five into one matrix, and some of them like offset-path could be very complex, so I have no idea where to start. Information is sparse from what I’ve been able to find.