Question

好的，所以在我的游戏中我有一段代码，每隔x个时间就产生一个精灵（＆＃39;敌人＆＃39;）。它会将精灵向上生成并且精灵会掉下来。

应该发生的事情是这样的：精灵掉下来，它接触地面或另一个敌人，然后它变成静态，所以它不会被移动。

这会发生什么：有时它会起作用，但有时候（特别是当x的时间量较小且精灵更频繁地产生时）精灵突然变为静态，而它仍然在空气。

为什么会这样？

以下是一些代码：

在GameScene.m中的

，在createSceneContents中，由didMoveToView调用的方法：

self.physicsWorld.contactDelegate = self;

SKSpriteNode *bottom = [SKSpriteNode spriteNodeWithColor:[SKColor whiteColor] size:CGSizeMake(self.frame.size.width, 10)];
bottom.position = CGPointMake(self.frame.size.width/2, 0);
bottom.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:bottom.size];
bottom.physicsBody.dynamic = NO;
bottom.physicsBody.restitution = 0;
bottom.physicsBody.categoryBitMask = self.bottomCategory;
bottom.physicsBody.contactTestBitMask = self.enemyCategory;

[self spawnObject];
[self addChild:self.world];
[self.world addChild:bottom];

spawnObject中的

，一个由createSceneContents调用的方法：

if (self.isPaused == NO){

    self.spawningSpeed = 1;
    self.enemyData = [[Enemy alloc]init];
    SKAction *wait = [SKAction waitForDuration:self.spawningSpeed];
    SKAction *run = [SKAction runBlock:^{

        SKSpriteNode *aNewEnemy = [self.enemyData createEnemyWithSize:self.customUnit andWidth:self.frame.size.width andHeight:self.frame.size.height + self.player.position.y andPlayerPosition:self.player.position.x];
        aNewEnemy.physicsBody.allowsRotation = NO;
        aNewEnemy.physicsBody.categoryBitMask = self.enemyCategory;
        aNewEnemy.physicsBody.collisionBitMask = self.enemyCategory | self.bottomCategory;
        aNewEnemy.physicsBody.contactTestBitMask = self.enemyCategory | self.bottomCategory;
        [self.world addChild:aNewEnemy];



    }];
    SKAction *action = [SKAction repeatActionForever:[SKAction sequence:@[wait,run]]];
    [self runAction:action withKey:@"action"];

in createEnemyWithSize：andWidth：andHeight：andPlayerPosition：，in Enemy.m：

self.enemy = [SKSpriteNode spriteNodeWithImageNamed:@"block.png"]; self.enemy.size = CGSizeMake(size - 5, size - 5); self.enemy.name = @"fallingEnemy"; self.enemy.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:CGSizeMake(size - 1, size - 1)]; self.enemy.physicsBody.restitution = 0; self.enemy.physicsBody.allowsRotation = NO; int column1 = width/7; int column2 = column1 * 2; int column3 = column1 * 3; int column4 = column1 * 4; int column5 = column1 * 5; int column6 = column1 * 6; int halfAColumn = column1/2; if (position > 0 && position < column1) { self.enemy.position = CGPointMake(halfAColumn, height - size); }else if (position > column1 && position < column2) { self.enemy.position = CGPointMake((column2-halfAColumn), height - size); }else if (position > column2 && position < column3) { self.enemy.position = CGPointMake((column3-halfAColumn), height - size); }else if (position > column3 && position < column4) { self.enemy.position = CGPointMake((column4-halfAColumn), height - size); }else if (position > column4 && position < column5) { self.enemy.position = CGPointMake((column5-halfAColumn), height - size); }else if (position > column5 && position < column6) { self.enemy.position = CGPointMake((column6-halfAColumn), height - size); }else if (position > column6 && position < width) { self.enemy.position = CGPointMake((width-halfAColumn), height - size); } return self.enemy;
在gameScene.m的didBeginContact中
：

SKPhysicsBody *enemyBodyA, *bottomBodyA, *enemyBodyB, *bottomBodyB; if (contact.bodyA.categoryBitMask == self.enemyCategory) { enemyBodyA = contact.bodyA; }else if (contact.bodyA.categoryBitMask == self.bottomCategory) { bottomBodyA = contact.bodyA; } if (contact.bodyB.categoryBitMask == self.enemyCategory) { enemyBodyB = contact.bodyB; }else if (contact.bodyB.categoryBitMask == self.bottomCategory) { bottomBodyB = contact.bodyB; } if (enemyBodyA == contact.bodyA && enemyBodyB == contact.bodyB) { [self.enemyData changeBlock]; NSLog(@"Change1"); } if (contact.bodyA == enemyBodyA && contact.bodyB == bottomBodyB) { NSLog(@"Change2"); [self.enemyData changeBlock]; } if (contact.bodyB == enemyBodyB && contact.bodyA == bottomBodyA) { NSLog(@"Change3"); [self.enemyData changeBlock]; }

在changeBlock中，在Enemy.m中：

-(void)changeBlock { self.enemy.physicsBody.dynamic = NO; self.enemy.name = @"staticEnemy"; }

createSceneContents中的位掩码值：

self.playerCategory = 1; self.enemyCategory = 2; self.edgeCategory = 4; self.bottomCategory = 8;

Answer 1

你可能会失去对另一个生成之前没有收到联系的敌人的引用。因此需要进行一些改变。你根本不需要敌人类中的self.enemy属性。

首先，修改changeBlock方法，以便可以在作为参数传递的任何块上执行。

-(void)changeBlock:(SKSpriteNode*)block {
    block.physicsBody.dynamic = NO;
    block.name = @"staticEnemy";
}

然后清理联系委托方法。

-(void)didBeginContact:(SKPhysicsContact *)contact
{
    SKPhysicsBody *firstBody, *secondBody;

    //This is a useful technique for organising bodies in the contact delegate
    if (contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask) {
        firstBody = contact.bodyA;
        secondBody = contact.bodyB;
    } else {
        firstBody = contact.bodyB;
        secondBody = contact.bodyA;
    }
    //Since enemyCategory < bottomCategory, the firstBody is an enemy node, and second either an enemy or bottom node

    if (firstBody.categoryBitMask == self.enemyCategory && secondBody.categoryBitMask == self.bottomCategory) {
        [self.enemyData changeBlock: (SKSpriteNode*)firstBody.node];
    } else if (firstBody.categoryBitMask == self.enemyCategory && secondBody.categoryBitMask == self.enemyCategory) {
        [self.enemyData changeBlock: (SKSpriteNode*)firstBody.node];
        [self.enemyData changeBlock: (SKSpriteNode*)secondBody.node];
    }
}

我不确定你的游戏是什么，所以改变是你想要的。但我希望你明白这一点。

物理学为什么不按照我想要的方式工作？

1 个答案: