关于objective C：iOS GLKit sprite之间的连续滚动sprite间隙

Continuous scrolling sprite on iOS GLKit gap between sprites

我一直在尝试在 iOS 上为我的 OpenGL ES 2.0 GLKit 游戏创建一个类。当我提高滚动速度时，sprite之间的间隙会变大。我在 Google 上进行了大量搜索，但没有找到适合我的答案。

我的滚动sprite类继承自一个具有位置、比例、子级等的”节点”(有点像 Cocos2D)。该类有一个sprite数组(节点)，它们以设定的速度在 x 轴上移动，当到达屏幕末端时，移动到最后一个sprite的右侧位置。

这是我的代码的主要部分：

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–(id)initWithTexture:(GLKTextureInfo *)texture effect:(GLKBaseEffect *)effect xScrollRange:(float)range yPosition:(float)y xScrollVelocity:(float)velocity{
if (self = [super init]) {
//set globals
self.velocity = velocity;
xRange = range;

//create a first sprite, set position, add to children
JGSprite *firstSprite = [[JGSprite alloc] initWithTexture:texture effect:effect];
firstSprite.position = GLKVector2Make(range, y);
[self.children addObject:firstSprite];

//calc how many sprites are needed to cover range+1
float spritesNum = range/firstSprite.contentSize.width;
int spritesNumRound = roundf(spritesNum)+1;

//add enough sprites to cover the screen
for (int i = 1; i < spritesNumRound; i++) {
//create, set position, add to children
JGSprite *sprite = [[JGSprite alloc] initWithTexture:texture effect:effect];
sprite.position = GLKVector2Make(range – (i*sprite.contentSize.width), y);
[self.children addObject:sprite];

}

//if moving left, set last sprite as right most
if (velocity < 0)
lastReorderedSprite = 0;
else //set left most
lastReorderedSprite = self.children.count–1;

}

return self;
}

–(void)update:(float)dt
{
//loop through sprites
for (JGNode *node in self.children)
{
//update sprites position
node.position = GLKVector2Make(node.position.x + self.velocity*dt, node.position.y);

//if moving left
if (self.velocity < 0)
{
//if reached gone off screen
if (node.position.x <= –node.contentSize.width/2)
{
//get last node
JGNode *lastSprite = [self.children objectAtIndex:lastReorderedSprite];

//set the position to the right of the last node
node.position = GLKVector2Make(lastSprite.position.x+lastSprite.contentSize.width, node.position.y);

//set re-positioned node as lastreordered
lastReorderedSprite = [self.children indexOfObject:node];
}
}
else //moving right
{
//gone off screen
if (node.position.x >= xRange+node.contentSize.width/2)
{
//get last node
JGNode *lastSprite = [self.children objectAtIndex:lastReorderedSprite];

//set the position to the left of the last node
node.position = GLKVector2Make(lastSprite.position.x–node.contentSize.width, node.position.y);

//set re-positioned node as lastreordered
lastReorderedSprite = [self.children indexOfObject:node];

}

}
}
}

如果有人能帮助我告诉我如何阻止间隙形成，将不胜感激 :) 提前致谢！

问题很可能是这一行：

1	node.position = GLKVector2Make(node.position.x + self.velocity*dt, node.position.y);

当你增加速度时，添加到 x 的量会增加。我的猜测是，您的一个对象的速度更新比其他对象晚。要修复它，只需让每个对象检查它是否是您希望它与其他对象之间的距离，如果不是，请将其移到那里。

Continuous scrolling sprite on iOS GLKit gap between sprites

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