Inside Macintosh: 3D Graphics Programming With QuickDraw 3D /

Chapter 17 - File Objects / File Objects Reference

File Objects Routines / Managing Unknown Objects

Q3Unknown_GetDirtyState

You can use the Q3Unknown_GetDirtyState function to get the current dirty state of an unknown object.

TQ3Status Q3Unknown_GetDirtyState (
TQ3UnknownObject unknownObject, 
TQ3Boolean *isDirty);

unknownObject

An unknown object.

isDirty

On exit, a Boolean value that indicates whether the specified unknown object is dirty (kQ3True) or not (kQ3False).

DESCRIPTION

The Q3Unknown_GetDirtyState function returns, in the isDirty parameter, the current dirty state of the unknown object specified by the unknownObject parameter. The dirty state of an unknown object is a Boolean value that indicates whether an unknown object is preserved in its original state (kQ3False) or should be updated when written back to the file object from which it was originally read (kQ3True).

An unknown object is marked as dirty when it's first read into memory. You can mark the object as not dirty (by calling Q3Unknown_SetDirtyState) if you know that no state or contextual information has changed in the object. The application that generated the unknown data is responsible for either discarding any dirty data or attempting to preserve it.