(NO.00004)iOS实现打砖块游戏(十三):伸缩自如,我是如意金箍棒(下)!

准备缩短反弹棒素材

和上一篇类似,我们如法炮制一张缩短后反弹棒的素材.

打开SpriteBuilder,新建StickShorter.ccb文件,按下图绘制其sprite帧和物理对象:



注意,在Ai中缩小和放大原来反弹棒的图片时,只要沿X轴一个方向放大即可,否则在Y轴方向也会变大,这就不是我们想要的了.

创建缩短道具星

我们用红色的星星表示缩短道具,所以spawStar中是这样写的:

case brkColorRed:
star = [Star starWithType:starTypeStickShorter];
break;

在GameScene.m中,在星星与反弹棒碰撞的代码中,加入如下代码:

case starTypeStickShorter:
@synchronized(self){
[self scheduleBlock:^(CCTimer *timer){
[Star doStickShorterWork:self.stickInGameScene];
} delay:0];
}
break;

好了,最后我们回到Star.m中添加doStickShorterWork方法:

+(void)doStickShorterWork:(Stick *)stick{
GameScene *gameScene = [GameScene sharedGameScene];
CCPhysicsNode *physicsWorld = (CCPhysicsNode*)stick.parent;

@synchronized(gameScene){
if ([stick.name isEqualToString:@"stickShorter"]) {
return;
}

if ([stick.name isEqualToString:@"stickLonger"]) {
Stick *stickNormal = [Stick stickNormal];
stickNormal.position = stick.position;
[stick removeFromParent];
//[physicsWorld removeChild:stick cleanup:YES];

[physicsWorld addChild:stickNormal];
gameScene.stickInGameScene = stickNormal;
return;
}
}

CGPoint position = stick.position;

__block Stick *stickShorter;

@synchronized(gameScene){
stickShorter = [Stick stickShorter];
[stick removeFromParent];
//[physicsWorld removeChild:stick cleanup:YES];
stickShorter.position = position;
[physicsWorld addChild:stickShorter];
stickShorter.visible = NO;
gameScene.stickInGameScene = stickShorter;

CCSprite *stickNode = (CCSprite*)[CCBReader load:@"Elements/StickNode"];
stickNode.position = stickShorter.position;
[gameScene addChild:stickNode z:50];

CCActionScaleTo *shorterAction = [CCActionScaleTo actionWithDuration:0.4f scaleX:0.5f scaleY:1.0f];
CCActionCallBlock *blk = [CCActionCallBlock actionWithBlock:^{
[stickNode removeFromParent];
stickShorter.visible = YES;
}];
CCActionSequence *seq = [CCActionSequence actions:shorterAction,blk,nil];
[stickNode runAction:seq];
}

[stickShorter scheduleBlock:^(CCTimer *timer){
@synchronized(gameScene){
Stick *stickNormal = [Stick stickNormal];
stickNormal.position = stickShorter.position;
[stickShorter removeFromParent];
[physicsWorld addChild:stickNormal];
gameScene.stickInGameScene = stickNormal;
}
} delay:10];
}

大家可以和变长的对应代码对比下,基本都是一样的.

下面编译运行游戏,效果如下:



大家可以在变短和变长中添加更多的特效,脑洞打开吧,童鞋们 ;)