Game->打砖块（源码：详解）

本游戏的设计步骤：

一、布局界面（把图片资源拉进Main.storyboard）

二、让小球动起来(给他一个初速度)

三、碰撞检测

1、屏幕碰撞

2、砖块碰撞

3、挡板碰撞

四、挡板移动

// ViewController.h

#import 

 @interface ViewController : UIViewController
 @property (strong, nonatomic) IBOutletCollection(UIImageView) NSArray *blockImageArray;

 @property (weak, nonatomic) IBOutlet UIImageView *paddleImage;

@property (weak, nonatomic) IBOutlet UIImageView *ballImage;

@end

// ViewController.m
#import "ViewController.h"

@interface ViewController ()
{
//用这个布尔值标示游戏是否正在进行中

BOOL isPlaying ;

  //加一个游戏时钟

CADisplayLink *_gameTimer;

//小球移动的速度

CGPoint _speed;
//手指移动位置的差值

CGFloat chaX;

 }

//1.检测屏幕碰撞


-(BOOL)checkWithScreen;

 //2.砖块碰撞检测

 -(BOOL)checkWithBlock;

 //3.挡板碰撞

 -(void)checkWithPandle;

@end

  @implementation ViewController

- (void)viewDidLoad {
[super viewDidLoad];

 }

#pragma mark 1 之前进行了页面的布局

//开始游戏

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
//游戏是否在进行中，如果游戏还没有开始就让游戏开始
if(!isPlaying){

    isPlaying = YES;
    
    //初始化一个游戏时钟，让step方法1/60秒执行一次
    
    _gameTimer = [CADisplayLink displayLinkWithTarget:self selector:@selector(step)];
    
    
    //将游戏放在runloop中
    
    /*
     *
     *runLoop做两件事情
     
     1.监听输入源，一般自动放到runLoop中
     
     2.监听定时器，一般需手动放到runLoop中
     
     */
    
   //[_gameTimer addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
    
    [_gameTimer addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
    
    //给小球一个初始的速度
    
    _speed = CGPointMake(0, -5);

   }
else
   {
    chaX = 0;

    }
}
#pragma mark 2  让小球动起来

 //让小球按照1/60的频率动起来

 -(void)step{

 // 如果返回值是yes就代表游戏失败
if ([self checkWithScreen]) {
    
    [self gameOver:@"再来一次"];
}

if ( [self checkWithBlock]) {
    
    [self gameOver:@"你真棒"];
}

[self checkWithPandle];




//小球每次的移动都是以上一次的位置作为参考

_ballImage.center = CGPointMake(_ballImage.center.x+_speed.x, _ballImage.center.y+_speed.y);

 }


#pragma mark 3  碰撞检测


 //1.检测屏幕碰撞

-(BOOL)checkWithScreen
{

BOOL isFail = NO;

//CGRectGetMInY  获取到小球的最小Y值
//1.顶部碰撞

if (CGRectGetMinY(_ballImage.frame) <= 0)
{
    //获取到绝对值
    
    _speed.y = fabsf(_speed.y);
}

//2.底部碰撞

if (CGRectGetMaxY(_ballImage.frame) >= (CGRectGetHeight(self.view.frame))) {
    
    
    isFail = YES;
}

//3左侧碰撞

if (CGRectGetMinX(_ballImage.frame) <= 0) {

    _speed.x = fabsf(_speed.x);
}

//4.右侧碰撞

if (CGRectGetMaxX(_ballImage.frame) >= CGRectGetWidth(self.view.frame)) {
    
    _speed.x = -1*fabsf(_speed.x);
}

return isFail;

}

 //2.检测板子是否碰撞

-(BOOL)checkWithBlock
{

BOOL gameWin = YES;

//通过for循环找到小球跟哪个色块碰撞了

for (UIImageView *block in _blockImageArray) {
    
    //CGRectIntersectsRect判断；两个视图是否碰撞
    
    if (CGRectIntersectsRect(block.frame , _ballImage.frame) && !block.hidden) {
        
        block.hidden = YES;
        
        _speed.y = fabsf(_speed.y);
    
    }
}

//判断所有的砖块是否都被隐藏了

for (UIImageView *block in _blockImageArray ) {
    
    if (block.hidden == NO) {
        
        gameWin = NO;
        
        break;
    }
}

return gameWin;

}

//3.挡板碰撞检测

  -(void)checkWithPandle
{

if(CGRectIntersectsRect(_ballImage.frame,_paddleImage.frame))
{
    _speed.y = -1*fabsf(_speed.y);
    
    //让小球的X方向的速度跟手指瞬时移动的速度相加
    
    _speed.x += chaX;
    
    NSLog(@"speed.x= %f",_speed.x);
}
}

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
 {
if (isPlaying) {
    
    //后去我点击的手指，touches是个集合，视图有多点触摸
    
    UITouch *touch = [touches anyObject];
    
    //获取到当前手指x的值
    
    CGFloat nowX = [touch locationInView:self.view].x;
    
    //获取到上一次手指x的值
    
    CGFloat lastX = [touch previousLocationInView:self.view].x;
    
    chaX = nowX -lastX;
    
    //让挡板移动
    
    _paddleImage.center = CGPointMake(_paddleImage.center.x+chaX,_paddleImage.center.y);
    
}
}



#pragma mark  从底部掉下去，游戏结束

-(void)gameOver:(NSString *)string
{
isPlaying = NO;

NSLog(@"%@",string);

//销毁定时器

[_gameTimer invalidate];

for (UIImageView *block in _blockImageArray) {
    
    block.hidden = YES;
    block.alpha = 0;
}
[UIView animateWithDuration:2.0 animations:^{
    for (UIImageView *block in _blockImageArray){
        
        block.hidden = NO;
        block.alpha = 1;
        
    }
}completion:^(BOOL finshed){

    _ballImage.center = CGPointMake(160, 377);

    _paddleImage.center = CGPointMake(160, 397);
}];


}



 - (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

@end