osx - Loading retina images from a subdirectory -

i'm using nsdrawninepartimage() draw stretchable control. since of course requires 9 separate images draw parts (plus extras drawn on that), have directory full of files top-left.png , top-left@2x.png. include directory in app bundle folder reference.

unfortunately, usual image-loading apis -[nsimage imagenamed:] , -[nsbundle imageforresource:] don't seem support subdirectories, if put slash in name. instead, i'm loading images method:

- (nsimage*)popoverimage:(nsstring*)name {     nsurl * url = [[nsbundle bundleforclass:self.class] urlforresource:name withextension:@"png" subdirectory:@"popover"];     return [[nsimage alloc] initwithcontentsofurl:url]; } 

this works fine normal displays, ignores 2x images retina displays. how can load retina images well? there better way loading 2 reps separately , combining them hand? i'd rather not use tiffs source files these resources, because use acorn image editor , last time checked, doesn't understand compound image formats well.

the simple answer use tiff's, concern misplaced. in xcode set project preference "combine high resolution artwork" , continue produce 2 png's acorn now. during build xcode combine 2 png's single tiff , store in bundle.