这更多的是一个数学问题而不是编程问题。
好吧,我想问一下你知道Material design中描述的插值器是什么:
它看起来是一个AccelerateDecelerateInterpolator
但减速效果衰减较慢。
我最好的孵化是:
public class MaterialInterpolator implements Interpolator {
@Override
public float getInterpolation(float input) {
if(input<1./3f)
return new AccelerateInterpolator().getInterpolation(input);
else
return new DecelerateInterpolator().getInterpolation(input);
}
}
这在值之间造成了差距:
Time / Value
...
0.3,0.09
0.317,0.100489
0.333,0.110889 <-- gap
0.35,0.57750005
0.367,0.599311
0.383,0.61931103
0.4,0.64
...
减速 AccelerateDecelerateInterpolator:
output = accelerateDecelerateInterpolator(decelerateInterpolator(input));
private float accelerateDecelerateInterpolator(float input) {
return (float)(Math.cos((input + 1) * Math.PI) / 2.0f) + 0.5f;
}
private float decelerateInterpolator(float input) {
// return 1.0f - (1.0f - input) * (1.0f - input);
return (float)(1.0f - Math.pow((1.0f - input), 2 * mFactor)); // default factor =1.f
}
提供类似于以下的费率:
以及值/时间曲线:
not sure if at the beginning is an output error or the actual behavior should be an output error
Source: http://www.google.com/design/spec/patterns/imagery-treatment.html http://www.google.com/design/spec/patterns/imagery-treatment.html