BeatGrid: Remove fuzzy behavior from findNthBeat

mixxxdj · Jul 12, 2021 · 95f7d36 · 95f7d36
1 parent d77c4f7
commit 95f7d36
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Showing 2 changed files with 3 additions and 115 deletions.
diff --git a/src/test/beatgridtest.cpp b/src/test/beatgridtest.cpp
@@ -99,100 +99,6 @@ TEST(BeatGridTest, TestNthBeatWhenOnBeat) {
     EXPECT_NEAR(position.value(), pGrid->findPrevBeat(position).value(), kMaxBeatError);
 }
 
-TEST(BeatGridTest, TestNthBeatWhenOnBeat_BeforeEpsilon) {
-    constexpr int sampleRate = 44100;
-    TrackPointer pTrack = newTrack(sampleRate);
-
-    constexpr double bpm = 60.1;
-    pTrack->trySetBpm(bpm);
-    constexpr double beatLengthFrames = 60.0 * sampleRate / bpm;
-
-    auto pGrid = BeatGrid::makeBeatGrid(pTrack->getSampleRate(),
-            QString(),
-            mixxx::Bpm(bpm),
-            mixxx::audio::kStartFramePos);
-
-    // Pretend we're just before the 20th beat.
-    constexpr mixxx::audio::FramePos kClosestBeat(20 * beatLengthFrames);
-    const mixxx::audio::FramePos position(kClosestBeat - beatLengthFrames * 0.005);
-
-    // The spec dictates that a value of 0 is always invalid and returns an invalid position
-    EXPECT_FALSE(pGrid->findNthBeat(position, 0).isValid());
-
-    // findNthBeat should return exactly the current beat if we ask for 1 or
-    // -1. For all other values, it should return n times the beat length.
-    for (int i = 1; i < 20; ++i) {
-        EXPECT_NEAR((kClosestBeat + beatLengthFrames * (i - 1)).value(),
-                pGrid->findNthBeat(position, i).value(),
-                kMaxBeatError);
-        EXPECT_NEAR((kClosestBeat + beatLengthFrames * (-i + 1)).value(),
-                pGrid->findNthBeat(position, -i).value(),
-                kMaxBeatError);
-    }
-
-    // Also test prev/next beat calculation.
-    mixxx::audio::FramePos prevBeat, nextBeat;
-    pGrid->findPrevNextBeats(position, &prevBeat, &nextBeat, true);
-    EXPECT_NEAR(kClosestBeat.value(), prevBeat.value(), kMaxBeatError);
-    EXPECT_NEAR((kClosestBeat + beatLengthFrames).value(), nextBeat.value(), kMaxBeatError);
-
-    // Also test prev/next beat calculation without snapping tolerance
-    pGrid->findPrevNextBeats(position, &prevBeat, &nextBeat, false);
-    EXPECT_NEAR((kClosestBeat - beatLengthFrames).value(), prevBeat.value(), kMaxBeatError);
-    EXPECT_NEAR(kClosestBeat.value(), nextBeat.value(), kMaxBeatError);
-
-    // Both previous and next beat should return the closest beat.
-    EXPECT_NEAR(kClosestBeat.value(), pGrid->findNextBeat(position).value(), kMaxBeatError);
-    EXPECT_NEAR(kClosestBeat.value(), pGrid->findPrevBeat(position).value(), kMaxBeatError);
-}
-
-TEST(BeatGridTest, TestNthBeatWhenOnBeat_AfterEpsilon) {
-    constexpr int sampleRate = 44100;
-    TrackPointer pTrack = newTrack(sampleRate);
-
-    constexpr double bpm = 60.1;
-    pTrack->trySetBpm(bpm);
-    constexpr double beatLengthFrames = 60.0 * sampleRate / bpm;
-
-    auto pGrid = BeatGrid::makeBeatGrid(pTrack->getSampleRate(),
-            QString(),
-            mixxx::Bpm(bpm),
-            mixxx::audio::kStartFramePos);
-
-    // Pretend we're just before the 20th beat.
-    constexpr mixxx::audio::FramePos kClosestBeat(20 * beatLengthFrames);
-    const mixxx::audio::FramePos position(kClosestBeat + beatLengthFrames * 0.005);
-
-    // The spec dictates that a value of 0 is always invalid and returns an invalid position
-    EXPECT_FALSE(pGrid->findNthBeat(position, 0).isValid());
-
-    // findNthBeat should return exactly the current beat if we ask for 1 or
-    // -1. For all other values, it should return n times the beat length.
-    for (int i = 1; i < 20; ++i) {
-        EXPECT_NEAR((kClosestBeat + beatLengthFrames * (i - 1)).value(),
-                pGrid->findNthBeat(position, i).value(),
-                kMaxBeatError);
-        EXPECT_NEAR((kClosestBeat + beatLengthFrames * (-i + 1)).value(),
-                pGrid->findNthBeat(position, -i).value(),
-                kMaxBeatError);
-    }
-
-    // Also test prev/next beat calculation.
-    mixxx::audio::FramePos prevBeat, nextBeat;
-    pGrid->findPrevNextBeats(position, &prevBeat, &nextBeat, true);
-    EXPECT_NEAR(kClosestBeat.value(), prevBeat.value(), kMaxBeatError);
-    EXPECT_NEAR((kClosestBeat + beatLengthFrames).value(), nextBeat.value(), kMaxBeatError);
-
-    // Also test prev/next beat calculation without snapping tolerance
-    pGrid->findPrevNextBeats(position, &prevBeat, &nextBeat, false);
-    EXPECT_NEAR(kClosestBeat.value(), prevBeat.value(), kMaxBeatError);
-    EXPECT_NEAR((kClosestBeat + beatLengthFrames).value(), nextBeat.value(), kMaxBeatError);
-
-    // Both previous and next beat should return the closest beat.
-    EXPECT_NEAR(kClosestBeat.value(), pGrid->findNextBeat(position).value(), kMaxBeatError);
-    EXPECT_NEAR(kClosestBeat.value(), pGrid->findPrevBeat(position).value(), kMaxBeatError);
-}
-
 TEST(BeatGridTest, TestNthBeatWhenNotOnBeat) {
     constexpr int sampleRate = 44100;
     TrackPointer pTrack = newTrack(sampleRate);

diff --git a/src/track/beatgrid.cpp b/src/track/beatgrid.cpp
@@ -184,27 +184,9 @@ audio::FramePos BeatGrid::findNthBeat(audio::FramePos position, int n) const {
         return audio::kInvalidFramePos;
     }
 
-    double beatFraction = (position - firstBeatPosition()) / m_beatLengthFrames;
-    double prevBeat = floor(beatFraction);
-    double nextBeat = ceil(beatFraction);
-
-    // If the position is within 1/100th of the next or previous beat, treat it
-    // as if it is that beat.
-    const double kEpsilon = .01;
-
-    if (fabs(nextBeat - beatFraction) < kEpsilon) {
-        // If we are going to pretend we were actually on nextBeat then prevBeat
-        // needs to be re-calculated. Since it is floor(beatFraction), that's
-        // the same as nextBeat.  We only use prevBeat so no need to increment
-        // nextBeat.
-        prevBeat = nextBeat;
-    } else if (fabs(prevBeat - beatFraction) < kEpsilon) {
-        // If we are going to pretend we were actually on prevBeat then nextBeat
-        // needs to be re-calculated. Since it is ceil(beatFraction), that's
-        // the same as prevBeat.  We will only use nextBeat so no need to
-        // decrement prevBeat.
-        nextBeat = prevBeat;
-    }
+    const double beatFraction = (position - firstBeatPosition()) / m_beatLengthFrames;
+    const double prevBeat = floor(beatFraction);
+    const double nextBeat = ceil(beatFraction);
 
     audio::FramePos closestBeatPosition;
     if (n > 0) {