Instance transformations provide a way of defining the model transformation drawing attribute for the duration of a called segment.
Instance transformations alter the retained-drawing output from special segments referred to as called segments. A called segment usually contains a subpicture duplicated several times in other subpictures. The instance transformation positions, sizes, and rotates the subpicture each time the segment is duplicated, because the transformation is set each time the segment is called. An instance transformation applies only to the called segment, and is reset on return to the calling segment. There is no query function associated with the transformation as it must be explicitly set for each called segment.
To apply an instance transformation, applications call GpiCallSegmentMatrix from the calling segment. GpiCallSegmentMatrix calls the segment and also applies the model transformation's scaling, rotation, and translation values in a one-dimensional array representing elements in the MATRIXLF structure and passes a segment identifier.