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画面上部から落ちるグリーンボール、イエローボール、オレンジボール、レッドボールの4つの要素があります

私はまた、私のタッチに従う要素、ブルーボールを持っています.

これらすべてがうまく機能しています！:D

ただし、緑のボールが青のボールと交差するタイミングを検出したい

私の青いボールはviewDidLoadでビューに配置され、4つのボールはonTimerを呼び出すnstimerに基づいてビューに配置されます。

5 つのボールはすべて同じレイヤーに作成されます。

[self.view insertSubview:greenImage belowSubview:bottomBar]

赤玉と緑玉がいつ衝突するかを検出できます。

if (CGRectIntersectsRect(greenImage.frame, redImage.frame)) {
                UIAlertView *message = [[UIAlertView alloc] initWithTitle:@"title" message:@"points" delegate:nil cancelButtonTitle:@"cool" otherButtonTitles:nil];
                [message show];
                [message release];
            }

「redImage」を「blueball」に置き換えると、アラートが表示されません。これは、同じメソッドで宣言されていないことが原因である可能性があると思います。

この衝突を検出する方法についてのアイデアはありますか?

ありがとう！

- - 編集 - -

以下の提案を使用して、次のことを行っています。

        greenImage = [[UIImageView alloc] initWithImage:green];
        greenImage.frame = CGRectMake(startX,0,43,43);
        [self.view insertSubview:greenImage belowSubview:bottomBar];
        [UIView beginAnimations:nil context:greenImage];
        [UIView setAnimationDuration:5 * speed];
        greenImage.frame = CGRectMake(startX, 500.0, 43,43);
        CGFloat r1 = greenImage.frame.size.width * .5;
        CGFloat r2 = blueBall.frame.size.width * .5;
        if(CGPointDistance(greenImage.center, blueBall.center) < (r1 + r2)){
            UIAlertView *message = [[UIAlertView alloc] initWithTitle:@"notice" message:@"hit!" delegate:nil cancelButtonTitle:@"cool" otherButtonTitles:nil];
            [message show];
            [message release];
        }

私が持っているこのメソッドの下に：

CGFloat CGPointDistance(CGPoint p1, CGPoint p2)
{
    return sqrtf((p1.x-p2.x)*(p1.x-p2.x) + (p1.y-p2.y)*(p1.y-p2.y));
}

エラーが発生します:

「CGPointDistance」の競合するタイプ

そして警告：

関数 'CGPointDistance' の暗黙の宣言

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2 に答える 2

1

2 つの円が交差しているかどうかを判断するには、中心間の距離が半径の合計より小さいかどうかを確認します。例えば...

CGFloat CGPointDistance(CGPoint p1, CGPoint p2)
{
    return sqrtf((p1.x-p2.x)*(p1.x-p2.x) + (p1.y-p2.y)*(p1.y-p2.y));
}

あなたの「ボール」はビューのようです...「ボール」がフレームを満たすと仮定すると、半径は幅の1/2になります...

BOOL BallsCollide(UIView *v1, UIView *v2)
{
    CGFloat r1 = v1.frame.size.width * .5;
    CGFloat r2 = v2.frame.size.width * .5;
    return CGPointDistance(v1.center, v2.center) < (r1 + r2);    
}

OK -- 簡単なサンプルをハックしました。ビューコントローラーにほとんどドロップできます。本番用には使用しないでください...どうやってできるかの例として...これを一番上に置き、残りのコントローラーをその下に置くことができます...

// I do not recommend using this approach for naything non-trivial,
// but it demonstrates the very simple collision detection for circle shapes.
@interface Ball : UIView {
}
@property (nonatomic, strong) UIColor *origColor;
@property (nonatomic, strong) UIColor *color;
+ (id)ballWithRadius:(CGFloat)radius color:(UIColor*)color;
- (BOOL)doesIntersectWith:(Ball*)ball;
@end
@implementation Ball
@synthesize color = _color;
@synthesize origColor = _origColor;
+ (id)ballWithRadius:(CGFloat)radius color:(UIColor*)color
{
    CGFloat diameter = radius * 2;
    Ball *ball = [[Ball alloc] initWithFrame:CGRectMake(0, 0, diameter, diameter)];
    ball.color = ball.origColor = color;
    ball.backgroundColor = [UIColor clearColor];
    return ball;
}
- (BOOL)doesIntersectWith:(Ball *)ball
{
    // Two circles overlap if the sum of their radii
    // is less than the distance between the two centers.
    CGFloat r1 = self.frame.size.width * .5;
    CGFloat r2 = ball.frame.size.width * .5;
    CGFloat diffX = self.center.x - ball.center.x;
    CGFloat diffY = self.center.y - ball.center.y;
    return (diffX*diffX) + (diffY*diffY) < (r1+r2)*(r1+r2);
}
- (BOOL)containsPoint:(CGPoint)point
{
    // Contains a point if distance from center is less than radius
    CGFloat r = self.frame.size.width *.5;
    CGFloat diffX = self.center.x - point.x;
    CGFloat diffY = self.center.y - point.y;
    return (diffX*diffX) + (diffY*diffY) < r*r;
}
- (void)drawRect:(CGRect)rect
{
    CGContextRef context = UIGraphicsGetCurrentContext();
    [self.color setFill];
    [self.color setStroke];
    CGContextSetLineWidth(context, 1);
    CGContextFillEllipseInRect(context, self.bounds);
}
@end


@interface CollideVC() {
    NSMutableDictionary *activeTouches;
    NSMutableSet *currentCollisions;
}
@end

@implementation CollideVC
- (void)ball:(Ball*)ball touched:(UITouch*)touch
{
    [activeTouches setObject:ball forKey:[NSValue valueWithPointer:(__bridge void*)touch]];
}
- (Ball*)getBallTouchedBy:(UITouch*)touch
{
    return [activeTouches objectForKey:[NSValue valueWithPointer:(__bridge void*)touch]];
}
- (void)stopTouch:(UITouch*)touch
{
    [activeTouches removeObjectForKey:[NSValue valueWithPointer:(__bridge void*)touch]];
}
- (void)ball:(Ball*)ball1 hasCollidedWith:(Ball*)ball2
{
    [currentCollisions addObject:ball1];
    [currentCollisions addObject:ball2];
    ball1.color = ball2.color = [UIColor yellowColor];
    [ball1 setNeedsDisplay];
    [ball2 setNeedsDisplay];
}

// NOTE: You should delegate handling of collisions...
- (void)checkForCollisions
{
    // Should filter those that don't actually need redisplay...
    // For simplicity, all that were or are colliding get it...
    [currentCollisions enumerateObjectsUsingBlock:^(Ball *ball, BOOL *stop) {
        [ball setNeedsDisplay];
        ball.color = ball.origColor;
    }];
    [currentCollisions removeAllObjects];
    NSArray *views = self.view.subviews;
    for (size_t i = 0; i < views.count; ++i) {
        id v = [views objectAtIndex:i];
        if (![v isKindOfClass:[Ball class]]) continue;
        Ball *ball1 = v;
        for (size_t j = i+1; j < views.count; ++j) {
            v = [views objectAtIndex:j];
            if (![v isKindOfClass:[Ball class]]) continue;
            Ball *ball2 = v;
            if ([ball1 doesIntersectWith:ball2]) {
                [self ball:ball1 hasCollidedWith:ball2];
            }
        }
    }
}
- (void)addBallWithRadius:(CGFloat)radius point:(CGPoint)point color:(UIColor*)color
{
    Ball *ball = [Ball ballWithRadius:radius color:color];
    ball.center = point;
    [self.view addSubview:ball];
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    for (UITouch *touch in touches) {
        CGPoint touchLocation = [touch locationInView:self.view];
        for (Ball *ball in self.view.subviews) {
            if ([ball containsPoint:touchLocation]) {
                [self ball:ball touched:touch];
            }
        }
    }
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    for (UITouch *touch in touches) {
        // Use relative distance so center does nt jump to tap location.
        CGPoint prev = [touch previousLocationInView:self.view];
        CGPoint curr = [touch locationInView:self.view];
        CGPoint c = [self getBallTouchedBy:touch].center;        
        [self getBallTouchedBy:touch].center = CGPointMake(c.x+curr.x-prev.x, c.y+curr.y-prev.y);
    }
    // NOTE: This does not check the path between the moves, only the new point.
    // So a fast movement "past" the other object will not get detected.
    // If you want to do comple detection, use an existing engine
    [self checkForCollisions];
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    for (UITouch *touch in touches) {
        [self stopTouch:touch];
    }
}
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
    [self touchesEnded:touches withEvent:event];
}

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}
- (void)viewDidLoad
{
    [super viewDidLoad];
    activeTouches = [NSMutableDictionary dictionary];
    currentCollisions = [NSMutableSet set];
    [self addBallWithRadius:20 point:CGPointMake(110, 100) color:[UIColor blueColor]];
    [self addBallWithRadius:20 point:CGPointMake(200, 200) color:[UIColor redColor]];
    [self addBallWithRadius:20 point:CGPointMake(235, 250) color:[UIColor greenColor]];
}
于 2012-04-11T22:16:58.820 に答える
0

上記のコードを少し変更するだけで、これが役立つ場合があります。

-(CGFloat)CGPointDistance:(CGPoint)p1 p2:(CGPoint)p2
{
    return sqrtf(powf(p1.x - p2.x) + powf(p1.y-p2.y));
}

-(BOOL)DidCollide:(View*)v1 v2:(View*)v2 v1Radius:(CGFloat)v1Radius v2Radius:(CGFloat)v2Radius
{
    CGFloat r1 = v1.frame.size.width * v1Radius;
    CGFloat r2 = v2.frame.size.width * v2Radius;
    return [self PointDistance:v1.center p2:v2.center] < (r1 + r2)
}

衝突をチェックするには、あなただけのことをしてください

if([self DidCollide:view1 v2:view2 v1Radius:radius v2Radius:radius])
{
    //do something
}
于 2013-01-08T20:27:05.217 に答える