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,精灵之间的间隙会变大。我在Google上做了很多搜索,但没有找到对我有用的答案。
我的滚动精灵类继承自具有位置,比例,孩子等的“节点”(有点像Cocos2D)。该类有一个精灵数组(节点),它们在x轴上以设定的速度移动,当到达屏幕的末端时移动到最后一个精灵的正确位置。
以下是我的代码的主要部分:
-(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];
}
}
}
}
如果有人可以通过告诉我如何停止形成间隙来提供帮助,那将非常感谢:)提前致谢!
答案 0 :(得分:2)
问题很可能是这一行:
node.position = GLKVector2Make(node.position.x + self.velocity*dt, node.position.y);
增加速度时,添加到x
的数量会增加。我的猜测是你的一个物体的速度比其他物体更新。要解决这个问题,只需让每个对象检查它是否与其他对象有距离,如果不是,请将其移动到那里。