【发布时间】:2015-05-27 05:38:55
【问题描述】:
我有一个方法,每次按下空格键时,它会分配一个子弹并动画它从宇宙飞船的前面移动到屏幕的顶部。
同时,我在 NSImageViews 中有小行星,它们使用 NSTimer 重复播放从屏幕顶部到屏幕底部的动画。
在另一个计时器重复访问的碰撞检测方法中,我将两个图像视图放入边界圆圈并使用圆相交方法检查碰撞。
问题是子弹/小行星通常不会相交。它仅在我的宇宙飞船与屏幕上出现的小行星对齐时才有效。即使小行星明显相交,我也不能只是压制火力并到处喷洒子弹来摧毁小行星。
有人有解决办法吗?
我的导弹 - NSTimer 经常访问的小行星碰撞检测方法:
// Missile - White Asteroid collision.
if (CGRectIntersectsRect(_missile.frame, _asteroid.frame)) {
// set bounding bullet circle.
_missileCircle.centerX = _missile.frame.origin.x + _missile.frame.size.width / 2;
_missileCircle.centerY = _missile.frame.origin.y + _missile.frame.size.height / 2;
_missileCircle.radius = _missile.frame.size.height / 2;
// Set bounding asteroid circle
_astCircle.centerX = _asteroid.frame.origin.x +_asteroid.frame.size.width / 2;
_astCircle.centerY = _asteroid.frame.origin.y +_asteroid.frame.size.height / 2;
_astCircle.radius = _asteroid.frame.size.height / 2 - 10;
if ([self Circle: _astCircle intersectsCircle: _missileCircle]) {
NSLog(@"Missile intersection");
[_missile removeFromSuperview];
[_asteroid removeFromSuperview];
}
}
这是我用空格键激活的导弹动画方法:
-(void) animateMissile
{
_missile = [[NSImageView alloc]init];
[_missile setImage:[NSImage imageNamed:@"Brown-Bullet"]];
[_missile setFrame: CGRectMake(_spaceship.frame.origin.x + 21, _spaceship.frame.origin.y + 40, 10, 15)];
[self addSubview:_missile];
[NSAnimationContext runAnimationGroup:^(NSAnimationContext *context) {
context.duration = 1.5;
[context setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear]];
_missile.animator.frame = CGRectOffset(_missile.frame, 0, self.bounds.size.height+12);
} completionHandler:nil];
}
以及用NSTimer激活的小行星动画方法:
-(void) animateDarkAst:(NSTimer *) timer
{
int randX = arc4random_uniform(self.bounds.size.width);
int randSize = 40 + arc4random() % (120-40+1);
double speed = [self randomDoubleBetween:1.0 and: 2.0];
CGPoint start = CGPointMake(randX, self.bounds.size.height);
[_asteroidDark setFrame:CGRectMake(start.x, start.y, randSize, randSize)];
[self addSubview:_asteroidDark];
[NSAnimationContext runAnimationGroup:^(NSAnimationContext *context) {
context.duration = speed;
[context setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear]];
_asteroidDark.animator.frame = CGRectOffset(_asteroidDark.frame, 0, -self.bounds.size.height * 2);
} completionHandler:nil];
}
【问题讨论】:
标签: animation collision-detection