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POmultiple identical pointers, can't figure out why
 

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  1. POmultiple identical pointers, can't figure out why
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    <p>I'm new to Objective-C, I feel like I'm probably just making a dumb mistake, but I have tried googling this with no luck (maybe I'm just not searching the right things)</p> <p>Essentially, I tried to write my own object class, and then make several instances of it, but the data seems locked together; Changing the data for any one reference changes it for all of them.</p> <p>here's where I make the objects and use them.</p> <pre><code>@implementation Drawing //leaving many functions out as they are not part of the problem Ball * balls[10]; int numPoints; //this gets called first - (id) initWithCoder: (NSCoder *)aDecoder { //leaving out loading of images..... numPoints=10; for(int i=0; i&lt;10; i++){ balls[i]=[[Ball alloc] init]; printf("bmem: %p\n",%balls[i]); float tpx=arc4random()%1024; float tpy=arc4random()%768; printf("randX: %f\n",tpx); printf("randY: %f\n",tpy); CGPoint tempPt = CGPointMake(tpx,tpy); printf("mem: %p\n",%tempPt); [balls[i] setLocation:tempPt]; } //code to start a timer on the drawRect function.... } //called regularly, every 30 seconds - (void) drawRect:(CGRect)rect { CGContextRef c=UIGraphicsGetCurrentContext(); CGContextClearRect(c, rect); for(int i=0; i&lt;numPoints; i++) { int ptX=[balls[i] getX]; int ptY=[balls[i] getY]; printf("index: %d\n",i); printf("x: %d\n",ptX); printf("y: %d\n",ptY); CGContextDrawImage(c, CGRectMake((int)ptX-WIDTH/2, (int)ptY-WIDTH/2, WIDTH, HEIGHT), image); } } </code></pre> <p>This program outputs a series of numbers which I thought would be useful. - "bmem", or the point in memory where the ball is, increments by regular intervals, as expected. - "randX" and "randY" are completely random, as they should be. - "mem", or the point in memory with the CGPoint, doesn't change</p> <p>and this is the ball object: </p> <pre><code>@implementation Ball int x; int y; -(void)setLocation:(CGPoint)loc{ x=loc.x; y=loc.y; } -(int)getX{ return x; } -(int)getY{ return y; } @end </code></pre> <p>At first I just though I had static attributes in the Ball class, but on googling I found out that objective-c does not have static attributes. I've blindly tried about a dozen different things with no success. I really just need this to work.</p>
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    1. USthe_underscore_key
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    1. COYou're showing us how you've implemented your class, but not how you're using the functions. Show us some of your function calls, how you're creating the CGPoint you're passing in e.t.c
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      1. POmultiple identical pointers, can't figure out why
      1. USNathan White
    2. CO@nathanwhite - The problem has been resolved. If you were wondering, the CGPoint was made with the "CGPointMake" function, part of the iOS libraries (not sure if obj-c or iOS). I left out the altering code because it was fairly intensive (dealing with iOS gestures, multi-touch input, fairly ugly) and I didn't want to freak out a possible helper with lines upon lines of extra code. Basically I had code which would move only one point, but they would all move together.
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      1. POmultiple identical pointers, can't figure out why
      1. USthe_underscore_key
    3. COThanks for getting back to me :)
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      1. USNathan White
 

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