我正在尝试使用Apple的SpriteKit进行侧滚动游戏.当想要制作无休止的滚动背景时,我遇到了这个
answer.
在实施解决方案后,它似乎确实有效,尽管它显着降低了我的FPS.这可能是由于在每一帧上重新计算图像位置的事实.
我觉得如果我可以使用一个或多个SKAction调用来处理这个动画会更好,但我不确定如何实现它.
思考？
到目前为止我在我的场景类中的代码(这只是在屏幕上激活了一次背景)
- (void)addBackgroundTileAtPoint:(CGPoint)point {
SKSpriteNode *bg = [SKSpriteNode spriteNodeWithImageNamed:@"background"];
bg.anchorPoint = CGPointZero;
bg.position = point;
bg.name = @"background";
bg.zPosition = -99;
[self addChild:bg];
SKAction *sequence = [SKAction sequence:@[
[SKAction moveByX:-(bg.size.width * 2) y:0 duration:10],[SKAction removeFromParent]
]];
[bg runAction: sequence];
}
解决方法
我在上一个开源项目中为一个特殊的需求做了一个名为SKScrollingNode的小组件：
SprityBird.
即使有3层或4层(视差),FPS也不是问题,但您可能需要自己尝试.
要使用它,您只需像任何其他节点一样添加它并给它一个scrollingSpeed likeo：
back = [SKScrollingNode scrollingNodeWithImageNamed:@"back" inContainerWidth:WIDTH(self)]; [back setScrollingSpeed:BACK_SCROLLING_SPEED]; [self addChild:back];
SKScrollingNode.h
@interface SKScrollingNode : SKSpriteNode @property (nonatomic) CGFloat scrollingSpeed; + (id) scrollingNodeWithImageNamed:(NSString *)name inContainerWidth:(float) width; - (void) update:(NSTimeInterval)currentTime; @end
SKScrollingNode.m
@implementation SKScrollingNode
+ (id) scrollingNodeWithImageNamed:(NSString *)name inContainerWidth:(float) width
{
UIImage * image = [UIImage imageNamed:name];
SKScrollingNode * realNode = [SKScrollingNode spriteNodeWithColor:[UIColor clearColor] size:CGSizeMake(width,image.size.height)];
realNode.scrollingSpeed = 1;
float total = 0;
while(total<(width + image.size.width)){
SKSpriteNode * child = [SKSpriteNode spriteNodeWithImageNamed:name ];
[child setAnchorPoint:CGPointZero];
[child setPosition:CGPointMake(total,0)];
[realNode addChild:child];
total+=child.size.width;
}
return realNode;
}
- (void) update:(NSTimeInterval)currentTime
{
[self.children enumerateObjectsUsingBlock:^(SKSpriteNode * child,NSUInteger idx,BOOL *stop) {
child.position = CGPointMake(child.position.x-self.scrollingSpeed,child.position.y);
if (child.position.x <= -child.size.width){
float delta = child.position.x+child.size.width;
child.position = CGPointMake(child.size.width*(self.children.count-1)+delta,child.position.y);
}
}];
}
@end
