This tool rotates the specified drawable if no selection exists. If a selection exists, the portion of the drawable which lies under the selection is cut from the drawable and made into a floating selection which is then rotated by the specified amount. The interpolation parameter can be set to TRUE to indicate that either linear or cubic interpolation should be used to smooth the resulting rotated drawable. The return value is the ID of the rotated drawable. If there was no selection, this will be equal to the drawable ID supplied as input. Otherwise, this will be the newly created and rotated drawable.