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  • Get CALayers view

    - by eaigner
    Hi, is it somehow possible to get the nearest "container" NSView of a CALayer? My problem is I'm managing tracking areas in my "container" NSView, and those need to be updated if a layer is moved/added etc. and i would like to automate that somehow instead of calling my -updateTrackingAreas function manually. Regards, Erik

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  • Tinting iPhone application screen red

    - by btschumy
    I'm trying to place a red tint on all the screens of my iPhone application. I've experimented on a bitmap and found I get the effect I want by compositing a dark red color onto the screen image using Multiply (kCGBlendModeMultiply). So the question is how to efficiently do this in real time on the iPhone? One dumb way might be to grab a bitmap of the current screen, composite into the bitmap and then write the composited bitmap back to the screen. This seems like it would almost certainly be too slow. In addition, I need some way of knowing when part of the screen has been redrawn so I can update the tinting. I can almost get the effect I want by putting a red, translucent, fullscreen UIView above everything. That tints everything red within further intervention on my part, but the effect is much "muddier" than results from the composite. So do any wizards out there know of some mechanism I can use to automatically composite the red over the app in similar fashion to what the translucent red UIView does?

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  • Batch faulting in a to-many relationship for a collection of objects

    - by indragie
    Scenario: Let's say I have an entity called Author that has a to-many relationship called books to the Book entity (inverse relationship author). If I have an existing collection of Author objects, I want to fault in the books relationship for all of them in a single fetch request. Code This is what I've tried so far: NSArray *authors = ... // array of `Author` objects NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"Book"]; fetchRequest.returnsObjectsAsFaults = NO; fetchRequest.predicate = [NSPredicate predicateWithFormat:@"author IN %@", authors]; Executing this fetch request does not result in the books relationship of the objects in the authors array being faulted in (inspected via logging). I've also tried doing the fetch request the other way around: NSArray *authors = ... // array of `Author` objects NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"Author"]; fetchRequest.returnsObjectsAsFaults = NO; fetchRequest.predicate = [NSPredicate predicateWithFormat:@"SELF IN %@", authors]; fetchRequest.relationshipKeypathsForPrefetching = @[@"books"]; This doesn't fire the faults either. What's the appropriate way of going about doing this?

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  • Animate the enabling of a UIBarButtonItem?

    - by Michael Brewer
    Is there a way to animate enabling or disabling a button? I've tried the following with no success. I'm guessing at this point that the enabled property cannot be animated like opacity can – but I hope I'm wrong. [UIView beginAnimations:nil context:nil]; [UIView setAnimationDuration:1.0f]; theButton.enabled = YES; [UIView setAnimationDelegate:self]; [UIView commitAnimations]; I can't believe there isn't a setEnabled:(BOOL)enabled animated:(BOOL)animated method.

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  • Handle row deletion in UITableViewController

    - by Kamchatka
    Hello, I hava a UINavigationController. The first level is a UITableViewController, the second level just shows details on one of the items of the table view. In this detail view, I can delete the item. It deletes the underlying managed object. When I pop back to the view, I have a crash. I understand why, it's because I didn't update the cached array that contains the data. I looked at several tutorials and I don't exactly understand how am I supposed to handle deletion. Maybe I don't understand exactly where I should fetch the objects in the model. Should I do a query for every cellForRowAtIndexPath and take the item in the result at position indexPath.row? It doesn't look efficient. Should I check for changes somewhere and recache the whole query in an array. I would think CoreData would provide something more natural but I couldn't find it so far. Thanks in advance.

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  • what is the idea behind scaling an image using lanczos?

    - by banister
    Hi, I'm interested in image scaling algorithms and have implemented the bilinear and bicubic methods. However, I have heard of the lanczos and other more sophisticated methods for even higher quality image scaling and I am very curious how they work. Could someone here explain the basic idea behind scaling an image using lanczos (both upscaling and downscaling) and why it results in higher quality? I do have a background in fourier analysis and have done some signal processing stuff in the past, but not with relation to image processing, so don't be afraid to use terms like "frequency response" and such in your answer :) EDIT: I guess what i really want to know is the concept and theory behind using a convolution filter for interpolation. (Note: i have already read the wikipedia article on lanczos resampling but it didn't have nearly enough detail for me) thanks alot!

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  • NSEntityDescription entityForName returning nil

    - by Kamchatka
    Hi, I did some changes to my model (but I don't want migration yet, so I just remove the application, built clean etc.) so my application works in the simulator. However, when I run it on the iPhone, I get the following error: *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'executeFetchRequest:error: A fetch request must have an entity.' I set the entity like this: NSEntityDescription *entity = [NSEntityDescription entityForName:@"Document" inManagedObjectContext:managedObjectContext]; My managedObjectContext is not nil. But I suspect that it doesn't load the object model correctly or something similar because If I display the entities in the model, the list is empty. How can I make sure the model is loaded? Thanks,

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  • Simulating 3D 'cards' with just orthographic rendering

    - by meds
    I am rendering textured quads from an orthographic perspective and would like to simulate 'depth' by modifying UVs and the vertex positions of the quads four points (top left, top right, bottom left, bottom right). I've found if I make the top left and bottom right corners y position be the same I don't get a linear 'skew' but rather a warped one where the texture covering the top triangle (which makes up the quad) seems to get squashed while the bottom triangles texture looks normal. I can change UVs, any of the four points on the quad (but only in 2D space, it's orthographic projection anyway so 3D space won't matter much). So basically I'm trying to simulate perspective on a two dimensional quad in orthographic projection, any ideas? Is it even mathematically possible/feasible? ideally what I'd like is a situation where I can set an x/y rotation as well as a virtual z 'position' (which simulates z depth) through a function and see it internally calclate the positions/uvs to create the 3D effect. It seems like this should all be mathematical where a set of 2D transforms can be applied to each corner of the quad to simulate depth, I just don't know how to make it happen. I'd guess it requires trigonometry or something, I'm trying to crunch the math but not making much progress. here's what I mean: Top left is just the card, center is the card with a y rotation of X degrees and right most is a card with an x and y rotation of different degrees.

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  • CATransaction: Layer Changes But Does Not Animate

    - by macinjosh
    I'm trying to animate part of UI in an iPad app when the user taps a button. I have this code in my action method. It works in the sense that the UI changes how I expect but it does not animate the changes. It simply immediately changes. I must be missing something: - (IBAction)someAction:(id)sender { UIViewController *aViewController = <# Get an existing UIViewController #>; UIView *viewToAnimate = aViewController.view; CALayer *layerToAnimate = viewToAnimate.layer; [CATransaction begin]; [CATransaction setAnimationDuration:1.0f]; CATransform3D rotateTransform = CATransform3DMakeRotation(0.3, 0, 0, 1); CATransform3D scaleTransform = CATransform3DMakeScale(0.10, 0.10, 0.10); CATransform3D positionTransform = CATransform3DMakeTranslation(24, 423, 0); CATransform3D combinedTransform = CATransform3DConcat(rotateTransform, scaleTransform); combinedTransform = CATransform3DConcat(combinedTransform, positionTransform); layerToAnimate.transform = combinedTransform; [CATransaction commit]; // rest of method... } I've tried simplifying the animation to just change the opacity (for example) and it still will not animate. The opacity just changes instantly. That leads me to believe something is not setup properly. Any clues would be helpful!

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  • Graphic programming over video playback

    - by ignatius
    I want to make some GUI mockup program for video player, so my idea is just to show some menu pictures over real video being playback. I have working program made with C and SDL just to load pictures and make a slideshow, but i don´t know how to put this over video with transparencies. Do you have a hint? ps. i usually program with python and C, so if there is any solution with this two i highly appreciate. Thanks!

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  • NSMutableArray of NSString in CoreData(iPhone

    - by azia
    I have a class, which describe an object for parsing XML. This class contains NSStrings and NSMutableArrays of NSStrings.I want to store parsed data using CoreData. How should I write CoreData model to store such objects if there is no such data type like NSMutableArray? Is there any way?

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  • iPhone game audio and background music

    - by Boon
    Have a few questions related to adding sounds to my game, specifically intro music (for splash), background music (loop) and button event sounds. Hope you can share your knowledge on this. 1) Should I use compressed sounds or uncompressed sounds? Or perhaps a combination of the two? Are there any limitations on the iPhone hardware that I should be aware of -- for example, the ability to play multiple compressed sounds? 2) What's the best audio format for my purpose? 3) For background music, I am thinking of using AVAudioPlayer. For button event sounds, I am thinking of using AudioServicesPlaySystemSound, what do you think? 4) Any other issues I should be aware of? Thank you!

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  • How to implement escape Sequence in SDL

    - by Sa'me Smd
    Im trying to use the STL library inside the SDL. but it gives me the error "undeclared identifier" Is there any way i can use "\n"or even cout<<endl; Can the function SDL_WarpMousewhich places the mouse cursor on a desired location on screen help me with this. Because i want to put a tile on the next line sequence. I hope you get the Question. Its very vague and messed up question though (sorry for that). EDIT: void putMap(SDL_Surface* tile, SDL_Surface* screen) { for(int y = 0; y < 21; y++) { for(int x = 0; x < 60; x++) { if(maze[x][y] != '#') { apply_surface( x*10 , y*10 , tile, screen); } } cout<<endl; } } c:\documents and settings\administrator\my documents\visual studio 2008\projects\craptest\craptest\main.cpp(605) : error C2065: 'cout' : undeclared identifier c:\documents and settings\administrator\my documents\visual studio 2008\projects\craptest\craptest\main.cpp(605) : error C2065: 'endl' : undeclared identifier This is my apply_surface funtion. void apply_surface( int x, int y, SDL_Surface* source, SDL_Surface* destination ) { //Make a temporary rectangle to hold the offsets SDL_Rect offset; //Give the offsets to the rectangle offset.x = x; offset.y = y; //Blit the surface SDL_BlitSurface( source, NULL, destination, &offset ); }

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  • When should a uniform be used in shader programming?

    - by Phineas
    In a vertex shader, I calculate a vector using only uniforms. Therefore, the outcome of this calculation is the same for all instantiations of the vertex shader. Should I just do this calculation on the CPU and upload it as a uniform? What if I have ten such calculations? If I upload a lot of uniforms in this way, does CPU-GPU communication ever get so slow that recomputing such values in the vertex shader is actually faster?

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  • Fastest possible way to render 480 x 320 background as iPhone OpenGL ES textures

    - by unknownthreat
    I need to display 480 x 320 background image in OpenGL ES. The thing is I experienced a bit of a slow down in iPhone when I use 512 x 512 texture size. So I am finding an optimum case for rendering iPhone resolution size background in OpenGL ES. How should I slice the background in this case to obtain the best possible performance? My main concern is speed. Should I go for 256 x 256 or other texture sizes here?

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  • Simple sound effect loop using AudioToolKit

    - by Typeoneerror
    I've created a few sounds for use in my game. I can play them at certain events without issue: // create sounds CFBundleRef mainBundle; mainBundle = CFBundleGetMainBundle(); _soundFileShake = CFBundleCopyResourceURL(mainBundle, CFSTR("shake"), CFSTR("wav"), NULL); AudioServicesCreateSystemSoundID(_soundFileShake, &_soundIdShake); // later... AudioServicesPlaySystemSound(_soundIdShake); The game has a mechanism which allows you to shake the device to activate some functionality. I've got the shaking code done so I get get a "shaking started" and "shaking ended" message to my game. What I need to have happen is start playing "shave.wav" when shaking starts and loop it until it stops. Is there a way to do this with AudioToolbox/AudioServices? How could I do this if not?

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  • Reverting CoreData data

    - by ndg
    I have an NSTableView which is populated via a CoreData-backed NSArrayController. Users are able to edit any field they choose within the NSTableView. When they select the rows that they have modified and press a button, the data is sent to a third-party webservice. Provided the webservice accepts the updated values, I want to commit those values to my persistent store. If, however, the webservice returns an error (or simply fails to return), I want the edited fields to revert to their original values. To complicate matters, I have a number of other editable controls, backed by CoreData, which do not need to resort to this behaviour. I believe the solution to this problem revolves around the creation of a secondary Managed Object context, which I would use only for values edited within that particularly NSTableView. But I'm confused as to how the two MOC would interact with each other. What's the best solution to this problem?

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  • Releasing instance if service not enabled?

    - by fuzzygoat
    I would just like to check if I have this right, I am creating an instance of CCLocationManager and then checking if location services are enabled. If it is not enabled I then report an error, release the instance and carry on, does that look/sound right? locationManager = [[CLLocationManager alloc] init]; BOOL supportsService = [locationManager locationServicesEnabled]; if(supportsService) { [locationManager setDelegate:self]; [locationManager setDistanceFilter:kCLDistanceFilterNone]; [locationManager setDesiredAccuracy:kCLLocationAccuracyBest]; [locationManager startUpdatingLocation]; } else { NSLog(@"Location services not enabled."); [locationManager release]; } ... ... ... more code cheers gary

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  • iPhone Audio Delay Line

    - by garylgsimpson
    I am looking into developing an audio delay line - external microphone to line out on the iPhone. Is there any sample code anyone could recommend? I have already been playing with SpeakHere and AurioTouch. AurioTouch is helpful although complex to sift through.

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  • Why do my buttons stay pressed?

    - by Timmmm
    In my activity I respond to an onClick() by replacing the current view with a new one (setContentView()). For some reason when I do this and then go back to the original view later the button I originally pressed still looks like it is pressed. If you 'refresh' it somehow (e.g. scroll over it with the trackball) then it reverts to the unpressed state. It's as if the button doesn't get the 'touch-up' event. The weird thing is: This only happens on my T-Mobile Pulse (android 1.5). It doesn't happen on the emulator. I've tried calling invalidate()/postInvalidate() on the view when I show it but it doesn't have any effect.

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