Fix asymmetric behavior of scroll direction #443
Merged
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When the scroll div is sufficiently large, you'll see a weird asymmetric behavior of scrolling; when you scroll towards the positive direction, the actual scroll happens after some ball movement, but when you scroll towards the negative direction, the scroll happens with a little ball movement.
This happens because the behavior of right shift
>> div
is not symmetric for positive and negative lhs. For example,1 >> 3
is zero, but-1 >> 3
is-1
. https://wandbox.org/permlink/M943OJ3soMrS4uH6This PR fixes the issue by using division
/ (1 << div)
instead, which truncates result towards zero.