>From the View Programming Guide for Cocoa ( http://developer.apple.com/DOCUMENTATION/Cocoa/Conceptual/CocoaViewsGuide/Optimizing/chapter_8_section_5.html#//apple_ref/doc/uid/TP40002978-CH11-SW4 ):
"In Mac OS X version 10.3 and later, views can constrain their drawing even further by using the NSView methods getRectsBeingDrawn:count: and needsToDrawRect:. These methods provide direct and indirect access, respectively, to the detailed representation of a view's invalid areas—that is, its list of non-overlapping rectangles—that the Application Kit maintains for each NSView instance. The Application Kit automatically enforces clipping to this list of rectangles, and you can further improve performance in views that do complex or expensive drawing by having them limit their drawing to objects that intersect any of the rectangles in this list." The parameter to -drawRect: specifies a rectangle that includes all those dirty rectangles. If, for example, your view consists of lots of expensive-to-draw regions, you can test each of those regions using -needsToDrawRect: to avoid drawing ones that aren't in a dirty region but wind up being included in the big rectangle. --Kyle Sluder _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
