Function that inserts a frame by copying the previous one That function doesn’t check if the frame already exists it MUST have been checked before !
Returns the index in the list for the right image, or False if the index doesn’t exists or if it is out of the lifespan of the object
Function that returns the object corresponding to the image
Function that returns the linearily interpolated polygon This function should be overwriten to handle non-polygon objects, or to process a non-linear interpolation