For each animcomp, you initially specify:

      * A pointer to the animcomp's controlling animob.

      * Initial and alternate views, their timing and order.

      * The initial inter-component drawing priorities (for multiple
        animcomp sequences, this specifies which sequence to display
        frontmost).

      * A pointer to a special animation routine related to this
        component (optional).

      * Your own extensions to this structure (optional).

 sequencing animcomps              linking multiple animcomp sequences 
 position of an animcomp           component ordering 
 specifying time for each image