## anim3D/src/RootGOPrivate.i3

Copyright (C) 1994, Digital Equipment Corporation
Digital Internal Use Only

Created on Wed Feb 16 18:24:35 PST 1994 by najork

INTERFACE RootGOPrivate;

IMPORT CameraGO, GraphicsBase;

FROM RootGO IMPORT T, Public;

REVEAL T <: Private;

TYPE
Private = Public OBJECT
cam  : CameraGO.T;
base : GraphicsBase.T;
END;

root.repair(damaged) redraws the scene rooted at root. Only those nodes that were marked as damaged are re-rendered, for the other nodes, cached values are used.

Nodes can be damaged in two ways: \begin{enumerate} \item By operations that change the scene DAG (i.e.\ the group operations add, remove, and flush). \item By changes in the value of an attached property. \end{enumerate}

Calling root.adjust(time) serves two purposes: It reevaluates all the properties attached to all descendants of root, and damages those nodes whose properties have changed since the last round of rendering. It also propagates damages up the scene DAGs.  root.repair(damaged) is called after all roots have been adjusted. The VAR parameter damaged is set to TRUE if there were any damages in the scene, otherwise, it remains unchanged. 

END RootGOPrivate.