cocos2d box2d 中的简单碰撞检测..碰撞时没有发生任何事情

Question

我正在尝试弄清楚如何做到这一点，我有一个名为“player”的精灵和一个名为“rock”的精灵 我正在尝试检测两个精灵之间的碰撞......但碰撞时没有任何反应！

这就是我所做的：

-(void)addRock {

rock = [CCSprite spriteWithFile:@"rock.png" 
                                     rect:CGRectMake(0, 0, 27, 40)]; 

// Determine where to spawn the target along the X axis
CGSize winSize = [[CCDirector sharedDirector] winSize];
int minX = rock.contentSize.width/2;
int maxX = winSize.width - rock.contentSize.width/2;
int rangeX = maxX - minX;
int actualX = (arc4random() % rangeX) + minX;
// Create the target slightly off-screen along the right edge,
// and along a random position along the X axis as calculated above
rock.position = ccp(actualX, 500);
rock.tag = 1;
[rockArray addObject:rock];
[self addChild:rock];

下面的播放器代码：

-(id) init{
if( (self=[super initWithColor:ccc4(255, 255, 255, 255)] )) {
    CGSize winSize = [[CCDirector sharedDirector] winSize];
    player = [CCSprite spriteWithFile:@"Player.png" 
                                           rect:CGRectMake(0, 0, 27, 40)];
    player.position = ccp(winSize.width/2, winSize.height/4+15); //position of where the player is placed
    player.tag = 2;
    [playerArray addObject:player];
    [self addChild:player];

精灵移动完成：

-(void)spriteMoveFinished:(id)sender {


CCSprite *sprite = (CCSprite *)sender;
[self removeChild:sprite cleanup:YES];

if (sprite.tag == 1) { // rock
    [rockArray removeObject:sprite];
} else if (sprite.tag == 2) { // players
    [playerArray removeObject:sprite];

init（数组初始化）：

rockArray = [[NSMutableArray alloc]init];
    playerArray = [[NSMutableArray alloc]init];
    [self schedule:@selector(update:)];

更新方法

- (void)update:(ccTime)dt {


    NSMutableArray *rocksToDelete = [[NSMutableArray alloc] init];
    for (rock in rockArray) {
        CGRect rockRect = CGRectMake(
                                       rock.position.x - (rock.contentSize.width/2), 
                                       rock.position.y - (rock.contentSize.height/2), 
                                       rock.contentSize.width, 
                                       rock.contentSize.height);


    NSMutableArray *playersToDelete = [[NSMutableArray alloc] init];
    for (player in playerArray) {
        CGRect pRect = CGRectMake(

                                        player.position.x - (player.contentSize.width/2), 
                                        player.position.y -(player.contentSize.height/2), 
                                        player.contentSize.width,
                                        player.contentSize.height);

        if (CGRectIntersectsRect(rockRect, pRect)) {
            [rocksToDelete addObject:rock];
        }

        for (rock in rocksToDelete) {
            [rockArray removeObject:rock];
            [self removeChild:rock cleanup:YES];                                    
        }

        if (rocksToDelete.count > 0) {
            [playersToDelete addObject:player];
        }
        [rocksToDelete release];

        for (player in playersToDelete) {
            [playerArray removeObject:player];
            [self removeChild:player cleanup:YES];
        }
        [playersToDelete release];

我整晚都在尝试解决我的问题。我似乎可以让碰撞检测工作。如果是这样，有人可以给我看一个简短的代码吗？

Answer 1

为了检查两个精灵之间的碰撞，您必须每帧（或您选择的频率）调用一个方法来检查是否发生了碰撞。
将以下代码添加到 init 方法中：

[self scheduleUpdate];

...这将在每个帧上调用以下方法（您必须添加到类实现中）：

-(void)update:(ccTime)delta {
   if (CGRectIntersectsRect(player.boundingBox, rock.boundingBox)) {
       //Do Stuff
   }
}

为了使前面的代码正常工作，您必须将 Player 和 Rock sprite 声明为成员变量因此它们可以在整个课堂上使用。

如果场景中有多个岩石精灵，您想要检查碰撞，则必须使用数组。简单示例：

1 在类接口中声明一个数组：

NSMutableArray *rockArray;

2 在 init 方法中为其分配内存

rockArray = [NSMutableArray array];

3 在“addRock”方法中将创建的岩石精灵添加到数组中，然后作为子元素添加到场景

-(void) addRock {
   CCSprite *rock = [CCSprite spriteWithFile:@"rock.png" 
                                     rect:CGRectMake(0, 0, 27, 40)];
   //...

   [rockArray addObject:rock];
   [self addChild:[rockArray lastObject]];
}

中 4 在“update”方法中现在，您可以循环遍历数组并检查岩石和岩石之间的碰撞。玩家

for (CCSprite *_rock in rockArray) {
   if (CGRectIntersectsRect(player.boundingBox, rock.boundingBox)) {
           //Do Stuff e.g remove that rock from the scene
           [self removeChild:_rock cleanup:YES];
       }
}

希望这有帮助；-)如有任何问题，请随时提出