blob: 519d39130455292c04d0da4a6137151fee1e29d7 [file] [log] [blame]
package com.android.launcher3;
import android.animation.TimeInterpolator;
public class LogAccelerateInterpolator implements TimeInterpolator {
int mBase;
int mDrift;
final float mLogScale;
public LogAccelerateInterpolator(int base, int drift) {
mBase = base;
mDrift = drift;
mLogScale = 1f / computeLog(1, mBase, mDrift);
}
static float computeLog(float t, int base, int drift) {
return (float) -Math.pow(base, -t) + 1 + (drift * t);
}
@Override
public float getInterpolation(float t) {
// Due to rounding issues, the interpolation doesn't quite reach 1 even though it should.
// To account for this, we short-circuit to return 1 if the input is 1.
return Float.compare(t, 1f) == 0 ? 1f : 1 - computeLog(1 - t, mBase, mDrift) * mLogScale;
}
}