Fix most common BPM sometimes displaying to be less or more than the map's BPM range #35827
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…length smaller or larger than the actual limits Closes ppy#35807. The reason this closes the aforementioned issue is as follows: Taking https://osu.ppy.sh/beatmapsets/1236180#osu/4650477 as the example, we have: ``` minBeatLength = 342.857142857143 maxBeatLength = 419.58041958042003 mostCommonBeatLength = 342.85700000000003 ``` Note that `mostCommonBeatLength < minBeatLength` here. Taking the inverse of that to compute BPM, we get ``` minBpm = 174.99999999999991 maxBpm = 142.99999999999986 mostCommonBpm = 175.00007291669704 ``` which without DT present doesn't do anything bad, but when DT is engaged (and thus BPM is multiplied by 1.5), midpoint rounding causes the min BPM to become 262, and the most common BPM to become 263.
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| double minBeatLength = ControlPointInfo.TimingPoints.Min(t => t.BeatLength); | ||
| double maxBeatLength = ControlPointInfo.TimingPoints.Max(t => t.BeatLength); |
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Just to be safe, I'd do .Select(t => t.BeatLength).DefaultIfEmpty(0).Min/Max() otherwise these throw exceptions on empty arrays.
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The theory here was that these cannot throw because the preceding mostCommon.beatLength == 0 guard would catch that scenario.
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Closes #35807.
The reason this closes the aforementioned issue is as follows:
Taking https://osu.ppy.sh/beatmapsets/1236180#osu/4650477 as the example, we have:
Note that
mostCommonBeatLength < minBeatLengthhere.Taking the inverse of that to compute BPM, we get
which without DT present doesn't do anything bad, but when DT is engaged (and thus BPM is multiplied by 1.5), midpoint rounding causes the min BPM to become 262, and the most common BPM to become 263.