feat: add support for scaling BPM by different ratios

src/controllers/controlpickermenu.cpp

@@ -237,12 +237,55 @@ ControlPickerMenu::ControlPickerMenu(QWidget* pParent)
 
     // BPM / Beatgrid
     QMenu* pBpmMenu = addSubmenu(tr("BPM / Beatgrid"));
-    addDeckAndSamplerControl("bpm", tr("BPM"), tr("BPM"), pBpmMenu, true);
-    addDeckAndSamplerControl("bpm_up", tr("BPM +1"), tr("Increase BPM by 1"), pBpmMenu);
-    addDeckAndSamplerControl("bpm_down", tr("BPM -1"), tr("Decrease BPM by 1"), pBpmMenu);
-    addDeckAndSamplerControl("bpm_up_small", tr("BPM +0.1"), tr("Increase BPM by 0.1"), pBpmMenu);
-    addDeckAndSamplerControl("bpm_down_small", tr("BPM -0.1"), tr("Decrease BPM by 0.1"), pBpmMenu);
-    addDeckAndSamplerControl("bpm_tap", tr("BPM Tap"), tr("BPM tap button"), pBpmMenu);
+    addDeckAndSamplerControl("bpm", 
+            tr("BPM"), 
+            tr("BPM"), 
+            pBpmMenu, 
+            true);
+    addDeckAndSamplerControl("bpm_up",
+            tr("BPM +1"),
+            tr("Increase BPM by 1"),
+            pBpmMenu);
+    addDeckAndSamplerControl("bpm_down",
+            tr("BPM -1"),
+            tr("Decrease BPM by 1"),
+            pBpmMenu);
+    addDeckAndSamplerControl("bpm_up_small",
+            tr("BPM +0.1"),
+            tr("Increase BPM by 0.1"),
+            pBpmMenu);
+    addDeckAndSamplerControl("bpm_down_small",
+            tr("BPM -0.1"),
+            tr("Decrease BPM by 0.1"),
+            pBpmMenu);
+    addDeckAndSamplerControl("bpm_tap",
+            tr("BPM Tap"),
+            tr("BPM tap button"),
+            pBpmMenu);
+    addDeckAndSamplerControl("beats_set_halve",
+            tr("BPM Halve"),
+            tr("Multiply current BPM by 0.5"),
+            pBpmMenu);
+    addDeckAndSamplerControl("beats_set_twothirds",
+            tr("BPM Two Thirds"),
+            tr("Multiply current BPM by 0.666"),
+            pBpmMenu);
+    addDeckAndSamplerControl("beats_set_threefourths",
+            tr("BPM Three Fourths"),
+            tr("Multiply current BPM by 0.75"),
+            pBpmMenu);
+    addDeckAndSamplerControl("beats_set_fourthirds",
+            tr("BPM Four Thirds"),
+            tr("Multiply current BPM by 1.333"),
+            pBpmMenu);
+    addDeckAndSamplerControl("beats_set_threehalves",
+            tr("BPM Three Halves"),
+            tr("Multiply current BPM by 1.5"),
+            pBpmMenu);
+    addDeckAndSamplerControl("beats_set_double",
+            tr("BPM Double"),
+            tr("Multiply current BPM by 2"),
+            pBpmMenu);
     pBpmMenu->addSeparator();
     addDeckAndSamplerControl("beats_adjust_faster",
             tr("Adjust Beatgrid Faster +.01"),

src/engine/controls/bpmcontrol.cpp

@@ -1,4 +1,4 @@
-#include "engine/controls/bpmcontrol.h"
+#include "engine/controls/bbpmcontrol.h"
 
 #include "control/controlencoder.h"
 #include "control/controllinpotmeter.h"
@@ -67,24 +67,30 @@ BpmControl::BpmControl(const QString& group,
     m_pLoopEndPosition = new ControlProxy(group, "loop_end_position", this);
 
     m_pLocalBpm = new ControlObject(ConfigKey(group, "local_bpm"));
-    m_pAdjustBeatsFaster = new ControlPushButton(ConfigKey(group, "beats_adjust_faster"), false);
+
+    m_pAdjustBeatsFaster = std::make_unique<ControlPushButton>(
+            ConfigKey(group, "beats_adjust_faster"), false);
     m_pAdjustBeatsFaster->setKbdRepeatable(true);
-    connect(m_pAdjustBeatsFaster, &ControlObject::valueChanged,
-            this, &BpmControl::slotAdjustBeatsFaster,
+    connect(m_pAdjustBeatsFaster.get(), &ControlObject::valueChanged,
+            this,
+            &BpmControl::slotAdjustBeatsFaster,
             Qt::DirectConnection);
-    m_pAdjustBeatsSlower = new ControlPushButton(ConfigKey(group, "beats_adjust_slower"), false);
+    m_pAdjustBeatsSlower = std::make_unique<ControlPushButton>(ConfigKey(group, "beats_adjust_slower"), false);
     m_pAdjustBeatsSlower->setKbdRepeatable(true);
-    connect(m_pAdjustBeatsSlower, &ControlObject::valueChanged,
-            this, &BpmControl::slotAdjustBeatsSlower,
+    connect(m_pAdjustBeatsSlower.get(),
+            &ControlObject::valueChanged,
+            this,
+            &BpmControl::slotAdjustBeatsSlower,
             Qt::DirectConnection);
-    m_pTranslateBeatsEarlier = new ControlPushButton(ConfigKey(group, "beats_translate_earlier"), false);
+
+    m_pTranslateBeatsEarlier = std::make_unique<ControlPushButton>(ConfigKey(group, "beats_translate_earlier"), false);
     m_pTranslateBeatsEarlier->setKbdRepeatable(true);
-    connect(m_pTranslateBeatsEarlier, &ControlObject::valueChanged,
+    connect(m_pTranslateBeatsEarlier.get(), &ControlObject::valueChanged,
             this, &BpmControl::slotTranslateBeatsEarlier,
             Qt::DirectConnection);
-    m_pTranslateBeatsLater = new ControlPushButton(ConfigKey(group, "beats_translate_later"), false);
+    m_pTranslateBeatsLater = std::make_unique<ControlPushButton>(ConfigKey(group, "beats_translate_later"), false);
     m_pTranslateBeatsLater->setKbdRepeatable(true);
-    connect(m_pTranslateBeatsLater, &ControlObject::valueChanged,
+    connect(m_pTranslateBeatsLater.get(), &ControlObject::valueChanged,
             this, &BpmControl::slotTranslateBeatsLater,
             Qt::DirectConnection);
     m_pTranslateBeatsMove = new ControlEncoder(ConfigKey(group, "beats_translate_move"), false);
@@ -94,6 +100,61 @@ BpmControl::BpmControl(const QString& group,
             &BpmControl::slotTranslateBeatsMove,
             Qt::DirectConnection);
 
+    m_pBeatsHalve = std::make_unique<ControlPushButton>(ConfigKey(group, "beats_set_halve"), false);
+    connect(m_pBeatsHalve.get(),
+            &ControlObject::valueChanged,
+            this,
+            [this](int value) {
+                if (value > 0) {
+                    slotScaleBpm(mixxx::Beats::BpmScale::Halve);
+                }
+            });
+    m_pBeatsTwoThirds = std::make_unique<ControlPushButton>(ConfigKey(group, "beats_set_twothirds"), false);
+    connect(m_pBeatsTwoThirds.get(),
+            &ControlObject::valueChanged,
+            this,
+            [this](int value) {
+                if (value > 0) {
+                    slotScaleBpm(mixxx::Beats::BpmScale::TwoThirds);
+                }
+            });
+    m_pBeatsThreeFourths = std::make_unique<ControlPushButton>(ConfigKey(group, "beats_set_threefourths"), false);
+    connect(m_pBeatsThreeFourths.get(),
+            &ControlObject::valueChanged,
+            this,
+            [this](int value) {
+                if (value > 0) {
+                    slotScaleBpm(mixxx::Beats::BpmScale::ThreeFourths);
+                }
+            });
+    m_pBeatsFourThirds = std::make_unique<ControlPushButton>(ConfigKey(group, "beats_set_fourthirds"), false);
+    connect(m_pBeatsFourThirds.get(),
+            &ControlObject::valueChanged,
+            this,
+            [this](int value) {
+                if (value > 0) {
+                    slotScaleBpm(mixxx::Beats::BpmScale::FourThirds);
+                }
+            });
+    m_pBeatsThreeHalves = std::make_unique<ControlPushButton>(ConfigKey(group, "beats_set_threehalves"), false);
+    connect(m_pBeatsThreeHalves.get(),
+            &ControlObject::valueChanged,
+            this,
+            [this](int value) {
+                if (value > 0) {
+                    slotScaleBpm(mixxx::Beats::BpmScale::ThreeHalves);
+                }
+            });
+    m_pBeatsDouble = std::make_unique<ControlPushButton>(ConfigKey(group, "beats_set_double"), false);
+    connect(m_pBeatsDouble.get(),
+            &ControlObject::valueChanged,
+            this,
+            [this](int value) {
+                if (value > 0) {
+                    slotScaleBpm(mixxx::Beats::BpmScale::Double);
+                }
+            });
+
     // Pick a wide range (kBpmRangeMin to kBpmRangeMax) and allow out of bounds sets. This lets you
     // map a soft-takeover MIDI knob to the BPM. This also creates bpm_up and
     // bpm_down controls.
@@ -141,11 +202,7 @@ BpmControl::~BpmControl() {
     delete m_pButtonTap;
     delete m_pTranslateBeats;
     delete m_pBeatsTranslateMatchAlignment;
-    delete m_pTranslateBeatsEarlier;
-    delete m_pTranslateBeatsLater;
     delete m_pTranslateBeatsMove;
-    delete m_pAdjustBeatsFaster;
-    delete m_pAdjustBeatsSlower;
 }
 
 mixxx::Bpm BpmControl::getBpm() const {
@@ -264,6 +321,22 @@ void BpmControl::slotTapFilter(double averageLength, int numSamples) {
     pTrack->trySetBeats(*newBeats);
 }
 
+void BpmControl::slotScaleBpm(mixxx::Beats::BpmScale bpmScale) {
+    const TrackPointer pTrack = getEngineBuffer()->getLoadedTrack();
+    if (!pTrack) {
+        return;
+    }
+    const mixxx::BeatsPointer pBeats = pTrack->getBeats();
+    if (!pBeats) {
+        return;
+    }
+    const auto newBeats = pBeats->tryScale(bpmScale);
+    if (!newBeats) {
+        return;
+    }
+    pTrack->trySetBeats(*newBeats);
+}
+
 // static
 double BpmControl::shortestPercentageChange(const double& current_percentage,
                                             const double& target_percentage) {

src/engine/controls/bpmcontrol.h

@@ -118,6 +118,7 @@ class BpmControl : public EngineControl {
     }
     double calcSyncAdjustment(bool userTweakingSync);
     void adjustBeatsBpm(double deltaBpm);
+    void slotScaleBpm(mixxx::Beats::BpmScale bpmScale);
 
     friend class SyncControl;
 
@@ -139,12 +140,19 @@ class BpmControl : public EngineControl {
 
     // The average bpm around the current playposition;
     ControlObject* m_pLocalBpm;
-    ControlPushButton* m_pAdjustBeatsFaster;
-    ControlPushButton* m_pAdjustBeatsSlower;
-    ControlPushButton* m_pTranslateBeatsEarlier;
-    ControlPushButton* m_pTranslateBeatsLater;
+    std::unique_ptr<ControlPushButton> m_pAdjustBeatsFaster;
+    std::unique_ptr<ControlPushButton> m_pAdjustBeatsSlower;
+    std::unique_ptr<ControlPushButton> m_pTranslateBeatsEarlier;
+    std::unique_ptr<ControlPushButton> m_pTranslateBeatsLater;
     ControlEncoder* m_pTranslateBeatsMove;
 
+    std::unique_ptr<ControlPushButton> m_pBeatsHalve;
+    std::unique_ptr<ControlPushButton> m_pBeatsTwoThirds;
+    std::unique_ptr<ControlPushButton> m_pBeatsThreeFourths;
+    std::unique_ptr<ControlPushButton> m_pBeatsFourThirds;
+    std::unique_ptr<ControlPushButton> m_pBeatsThreeHalves;
+    std::unique_ptr<ControlPushButton> m_pBeatsDouble;
+
     // The current effective BPM of the engine
     ControlLinPotmeter* m_pEngineBpm;