Hello, I'm working on optimizing a document based application, and I've found that overdrawing is a significant contributor to the (tolerable, but non-ideal) performance issues I am experiencing.
The reason overdrawing occurs is as follows: Let's say the user draws a line in the document from point A to point B. The display rect is calculated using the points on this line and inset so that the selection highlight of the line is also within the display rect. setNeedsDisplayInRect is invoked for this rectangle. In my document view class' drawRect: method, everything in the document overlapping the display rectangle is drawn. However, my pages are drawn as rectangular bezier paths with attached NSShadows, so I draw an entire page if it overlaps the display rectangle. The problem is that even though calling [pagePath fill] does not actually cause the document view to actually draw the entire contents of the fill (but rather what overlaps the display rectangle, as expected), subviews outside the display rectangle that overlap the page rectangle are recursively displayed in their entirety. I find this behavior to be somewhat bizarre, but nonetheless the solution seems to be to only draw a white rectangle using the NSIntersectionRect of both relevant rectangles. However, this causes a broken-up shadow appearance. Should I abandon the idea of a smooth NSShadow in favor of an additional black rectangle with 50% opacity instead? Is there a better way to draw a smooth shadow? Any advice would be of great help. Thanks, - Dave H _______________________________________________ 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
