On Apr 16, 2011, at 4:57 PM, eveningnick eveningnick wrote: > Could you give me a hint how did QuickTime Player developers manage to > display a window the way it looks now? Specifically i can't > understand, how they made the "Movie control" toolbar, that floats > only within the "movie window"?
At a guess, they are using Core Animation layers. They are probably manually repositioning the movie control's layer (or layer-backed view) manually in response to the mouse-dragging events, just as you would to reposition the window. > Reading through NSOpenGLView documentation, i found the note that this > view can't contain subviews. Though i am pretty sure the "movie view" > is NSOpenGLView (am i wrong here?). Do they display an another > "control" window somehow in an "always on top of the NSOpenGLView" > manner? Core Animation layers can contain OpenGL rendering while still permitting other layers on top. For example, see the LayerBackedOpenGLView sample code: http://developer.apple.com/library/mac/#samplecode/LayerBackedOpenGLView/ Alternatively, you can use a non-NSOpenGLView-derived view, backed by a CAOpenGLLayer (or hosting a layer hierarchy that includes one). See the CALayerEssentials sample code: http://developer.apple.com/library/mac/#samplecode/CALayerEssentials/ > I am wondering, why is NSOpenGLView considered to be the preferred way > to display a set of images? Why is every image operation revolving > around OpenGL? I understand that eventually it all comes through the > videoadapter, but what if i just display an RGB picture that i have in > an RGB buffer (CVImageBufferRef). Will OpenGL give me some benefits > just for rendering it on the view against drawing image onto something > like "NSImageView"? This is outside my area of expertise, but I'm not sure it's entirely true that OpenGL is _the_ preferred way to display sequences of images. I imagine that QTKit can do the same sort of thing quite handily. ;) And, of course, for simple animations, regular old Cocoa image drawing may suffice. (That doesn't necessarily imply the use of NSImageView. You can draw an NSImage from within the -drawRect: of any custom NSView class, for example.) The advantage of OpenGL is presumably performance gained from asynchrony -- being able to prepare a next frame for display while the GPU is working on displaying the current frame. Regards, Ken _______________________________________________ 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
