Beatloops snap to the closest (fractional) beat in quantized mode LP1752133

src/engine/controls/loopingcontrol.cpp

@@ -53,7 +53,7 @@ LoopingControl::LoopingControl(QString group,
     m_loopSamples.setValue(m_oldLoopSamples);
     m_currentSample.setValue(0.0);
     m_pActiveBeatLoop = NULL;
-
+    m_pRateControl = NULL;
     //Create loop-in, loop-out, loop-exit, and reloop/exit ControlObjects
     m_pLoopInButton = new ControlPushButton(ConfigKey(group, "loop_in"));
     connect(m_pLoopInButton, &ControlObject::valueChanged,
@@ -682,6 +682,10 @@ void LoopingControl::setLoopOutToCurrentPosition() {
     m_loopSamples.setValue(loopSamples);
 }
 
+void LoopingControl::setRateControl(RateControl* rateControl) {
+    m_pRateControl = rateControl;
+}
+
 void LoopingControl::slotLoopOut(double pressed) {
     if (m_pTrack == nullptr) {
         return;
@@ -1060,16 +1064,19 @@ void LoopingControl::slotBeatLoop(double beats, bool keepStartPoint, bool enable
             newloopSamples.start = currentSample;
         }
     } else {
-        // loop_in is set to the previous beat if quantize is on.  The
-        // closest beat might be ahead of play position which would cause a seek.
-        // TODO: If in reverse, should probably choose nextBeat.
+        // loop_in is set to the closest beat if quantize is on and the loop size is >= 1 beat.
+        // The closest beat might be ahead of play position and will cause a catching loop.
         double prevBeat;
         double nextBeat;
         pBeats->findPrevNextBeats(currentSample, &prevBeat, &nextBeat);
 
         if (m_pQuantizeEnabled->toBool() && prevBeat != -1) {
+            double beatLength = nextBeat - prevBeat;
+            double loopLength = beatLength * beats;
+
+            double closestBeat = pBeats->findClosestBeat(currentSample);
             if (beats >= 1.0) {
-                newloopSamples.start = prevBeat;
+                newloopSamples.start = closestBeat;
             } else {
                 // In case of beat length less then 1 beat:
                 // (| - beats, ^ - current track's position):
@@ -1078,15 +1085,29 @@ void LoopingControl::slotBeatLoop(double beats, bool keepStartPoint, bool enable
                 //
                 // If we press 1/2 beatloop we want loop from 50% to 100%,
                 // If I press 1/4 beatloop, we want loop from 50% to 75% etc
-                double beat_len = nextBeat - prevBeat;
-                double loops_per_beat = 1.0 / beats;
-                double beat_pos = currentSample - prevBeat;
-                int beat_frac =
-                        static_cast<int>(floor((beat_pos / beat_len) *
-                                                loops_per_beat));
-                newloopSamples.start = prevBeat + beat_len / loops_per_beat * beat_frac;
+                double samplesSinceLastBeat = currentSample - prevBeat;
+
+                // find the previous beat fraction and check if the current position is closer to this or the next one
+                // place the new loop start to the closer one
+                double previousFractionBeat = prevBeat + floor(samplesSinceLastBeat / loopLength) * loopLength;
+                double samplesSinceLastFractionBeat = currentSample - previousFractionBeat;
+
+                if (samplesSinceLastFractionBeat <= (loopLength / 2.0)) {
+                    newloopSamples.start = previousFractionBeat;
+                } else {
+                    newloopSamples.start = previousFractionBeat + loopLength;
+                }
             }
 
+            // If running reverse, move the loop one loop size to the left.
+            // Thus, the loops end will be closest to the current position
+            bool reverse = false;
+            if (m_pRateControl != NULL) {
+                reverse = m_pRateControl->isReverseButtonPressed();
+            }
+            if (reverse) {
+                newloopSamples.start -= loopLength;
+            }
         } else {
             newloopSamples.start = currentSample;
         }

src/engine/controls/loopingcontrol.h

@@ -8,11 +8,12 @@
 #include <QObject>
 #include <QStack>
 
-#include "preferences/usersettings.h"
+#include "control/controlvalue.h"
 #include "engine/controls/enginecontrol.h"
-#include "track/track.h"
+#include "engine/controls/ratecontrol.h"
+#include "preferences/usersettings.h"
 #include "track/beats.h"
-#include "control/controlvalue.h"
+#include "track/track.h"
 
 #define MINIMUM_AUDIBLE_LOOP_SIZE   300  // In samples
 
@@ -50,7 +51,7 @@ class LoopingControl : public EngineControl {
     double getSyncPositionInsideLoop(double dRequestedPlaypos, double dSyncedPlayPos);
 
     void notifySeek(double dNewPlaypos) override;
-
+    void setRateControl(RateControl* rateControl);
     bool isLoopingEnabled();
 
   public slots:
@@ -129,6 +130,7 @@ class LoopingControl : public EngineControl {
     ControlPushButton* m_pLoopHalveButton;
     ControlPushButton* m_pLoopDoubleButton;
     ControlObject* m_pSlipEnabled;
+    RateControl* m_pRateControl;
     ControlObject* m_pPlayButton;
 
     bool m_bLoopingEnabled;

src/engine/controls/ratecontrol.cpp

@@ -556,3 +556,10 @@ void RateControl::resetRateTemp(void)
 void RateControl::notifySeek(double playPos) {
     m_pScratchController->notifySeek(playPos);
 }
+
+bool RateControl::isReverseButtonPressed() {
+    if (m_pReverseButton) {
+        return m_pReverseButton->toBool();
+    }
+    return false;
+}

src/engine/controls/ratecontrol.h

@@ -78,6 +78,7 @@ class RateControl : public EngineControl {
     static void setRateRampSensitivity(int);
     static int getRateRampSensitivity();
     void notifySeek(double dNewPlaypos) override;
+    bool isReverseButtonPressed();
 
   public slots:
     void slotReverseRollActivate(double);

src/engine/enginebuffer.cpp

@@ -180,14 +180,13 @@ EngineBuffer::EngineBuffer(const QString& group, UserSettingsPointer pConfig,
     // quantization (alignment) of loop in/out positions and (hot)cues with
     // beats.
     QuantizeControl* quantize_control = new QuantizeControl(group, pConfig);
+    addControl(quantize_control);
+    m_pQuantize = ControlObject::getControl(ConfigKey(group, "quantize"));
 
     // Create the Loop Controller
     m_pLoopingControl = new LoopingControl(group, pConfig);
     addControl(m_pLoopingControl);
 
-    addControl(quantize_control);
-    m_pQuantize = ControlObject::getControl(ConfigKey(group, "quantize"));
-
     m_pEngineSync = pMixingEngine->getEngineSync();
 
     m_pSyncControl = new SyncControl(group, pConfig, pChannel, m_pEngineSync);
@@ -198,9 +197,12 @@ EngineBuffer::EngineBuffer(const QString& group, UserSettingsPointer pConfig,
     addControl(m_pVinylControlControl);
 #endif
 
+    // Create the Rate Controller
     m_pRateControl = new RateControl(group, pConfig);
     // Add the Rate Controller
     addControl(m_pRateControl);
+    // Looping Control needs Rate Control for Reverse Button
+    m_pLoopingControl->setRateControl(m_pRateControl);
 
     // Create the BPM Controller
     m_pBpmControl = new BpmControl(group, pConfig);
@@ -532,6 +534,10 @@ TrackPointer EngineBuffer::getLoadedTrack() const {
     return m_pCurrentTrack;
 }
 
+bool EngineBuffer::isReverse() {
+    return m_reverse_old;
+}
+
 void EngineBuffer::ejectTrack() {
     // clear track values in any case, this may fix Bug #1450424
     //qDebug() << "EngineBuffer::ejectTrack()";

src/engine/enginebuffer.h

@@ -146,6 +146,8 @@ class EngineBuffer : public EngineObject {
     bool getQueuedSeekPosition(double* pSeekPosition);
     TrackPointer getLoadedTrack() const;
 
+    bool isReverse();
+
     double getExactPlayPos();
     double getVisualPlayPos();
     double getTrackSamples();