Mac Dock就像放大iPad一样

Question

我试图通过iCarousel库为我的iPad应用程序带出像放大效果一样的底座.有了这个我可以使用下面的代码放大旋转木马的中心项目,但尝试缩放中心项目的相邻项目,缩放级别略小于中心项目.

- (CATransform3D)carousel:(iCarousel *)_carousel itemTransformForOffset: 
                         :(CGFloat)offset baseTransform:(CATransform3D)transform
 {
    CGFloat MAX_SCALE = 1.95f; //max scale of center item 
    CGFloat MAX_SHIFT = 40.0f; //amount to shift items to keep spacing the same 

    CGFloat shift = fminf(1.0f, fmaxf(-1.0f, offset));
    CGFloat scale = 1.0f + (1.0f - fabs(shift)) * (MAX_SCALE - 1.0f);
    transform = CATransform3DTranslate(transform, 
    offset * _carousel.itemWidth * 1.08f + shift * MAX_SHIFT, 0.0f, 0.0f);
    return CATransform3DScale(transform, scale, scale, scale);
}

期待任何形式的帮助.谢谢.

Answer 1

这个功能可能是你的答案:

它的图形(对于scaleMax = 3,xFactor = 1):

此功能直接用于从轮播偏移量计算比例因子.此外,您需要将元素向左和向右移动,以便不重叠(如您所做).这可以通过使用函数的积分来移动项目来完成,这有效,但是中心的间隙很大.或者可以通过获取所有缩放项目的总和来手动计算.间隙可以保持不变,也可以单独缩放.

请注意,中心的刻度等于1,边缘下降到1/scale_max.这是因为按比例缩小不会产生不希望的像素化效果.根据需要将项目视图显示在中心,边缘上的视图将缩小.

这可能是用法:

-(CGFloat) scaleForX:(CGFloat)x xFactor:(CGFloat)xFactor centerScale:(CGFloat)centerScale
{
    return (1+1/(sqrtf(x*x*x*x*xFactor*xFactor*xFactor*xFactor+1))*(centerScale-1.0))/centerScale;
}

- (CATransform3D)carousel:(iCarousel *)carousel itemTransformForOffset:(CGFloat)offset baseTransform:(CATransform3D)transform
{
    //items in the center are scaled by this factor
    const CGFloat centerScale = 4.0f;
    //the larger the xFactor, the smaller the magnified area
    const CGFloat xFactor = 1.5f;
    //should the gap also be scaled? or keep it constant.
    const BOOL scaleGap = NO;

    const CGFloat spacing = [self carousel:carousel valueForOption:iCarouselOptionSpacing withDefault:1.025];
    const CGFloat gap = scaleGap?0.0:spacing-1.0;

    //counting x offset to keep a constant gap
    CGFloat scaleOffset = 0.0;
    float x = fabs(offset);
    for(;x >= 0.0; x-=1.0)
    {
        scaleOffset+=[self scaleForX:x xFactor:xFactor centerScale:centerScale];
        scaleOffset+= ((x>=1.0)?gap:x*gap);
    }
    scaleOffset -= [self scaleForX:offset xFactor:xFactor centerScale:centerScale]/2.0;
    scaleOffset += (x+0.5)*[self scaleForX:(x+(x>-0.5?0.0:1.0)) xFactor:xFactor centerScale:centerScale];
    scaleOffset *= offset<0.0?-1.0:1.0;
    scaleOffset *= scaleGap?spacing:1.0;

    CGFloat scale = [self scaleForX:offset xFactor:xFactor centerScale:centerScale];
    transform = CATransform3DTranslate(transform, scaleOffset*carousel.itemWidth, 0.0, 0.0);
    transform = CATransform3DScale(transform, scale, scale, 1.0);
    return transform;
}

结果:

您可以尝试更改不同行为的常量.同样将指数改为另一个偶数可以进一步加宽峰值并使下降锐化到最小比例.