https://drafts.fxtf.org/geometry/#dom-dommatrix-rotateself

In some places, degrees are specifically mentioned. In other places, it does not state. For example:

> 1. rotateSelf(rotX, rotY, rotZ)
> 2. If rotY and rotZ are both missing, set rotZ to the value of rotX and set rotX and rotY to zero.
> 3. If rotY is still missing, set rotY to zero.
> 4. If rotZ is still missing, set rotZ to zero.
> 5. If rotX or rotY are non-zero, set is2D of the current matrix to false.
> 6. Post-multiply the current matrix by each of its 3 rotation matrices about the major axes, first Z using rotZ, then Y using rotY, then X using rotX.
> 7. Return the current matrix.


As an implementor, I would assume this means radians, except that other parts of the document mention degrees.