On 29 Oct, 2012, at 11:43 PM, Ken Thomases <k...@codeweavers.com> wrote:
> On Oct 29, 2012, at 8:22 AM, Roland King wrote: > >> I have a graphics context and a path and I want to clip everything inside >> the path, ie not display it, and leave everything outside the path >> displayed. The path is simple and doesn't cross itself, for sake of example >> it may as well be a circle. If I start with a clip-free GC and set that >> circle as a clipping path, I'll get the opposite, everything in the circle >> will show, how do I do the other way around? Does it work if I set a path at >> the bound rect of the GC plus my shape in the middle? That would seem to >> have two crossings to get into the shape, one at the bounds of the rect, one >> as you cross the shape, which should mean everything inside the shape is >> 'outside' but does a path at the very extremities of the GC, or even outside >> it, count as 'crossed'? > > Yes, that's the correct way. A clip path is geometric. It doesn't matter > what the bounds of the GC are. Obviously, only pixels inside the GC bounds > can possibly be painted, but the determination of what's clipped or not is > determined using the clipping path as a mathematical construct. > > You don't need to use the exact bounds of the GC. You can use an outer path > that's larger than the GC bounds. Although, I'm not sure if constructing one > from CGRectInfinite is wise, you can probably use origin -30,000,-30,000 size > 60,000x60,000 or something. > > Regards, > Ken > Perfect, thanks. That's how I thought it should work, I haven't made it work yet so somewhere I've messed up, let me strip it down and go back to a simpler project to find the error. _______________________________________________ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
