Eliminate misleading precision in the bpm and rate displays.

* Show only one decimal place for bpm and rate
* Waveform stretch reacts more slowly to small changes in rate.
* Vinyl control bpm updates are much more sticky.

5 files changed, 42 insertions, 11 deletions

diff --git a/src/vinylcontrol/vinylcontrolxwax.cpp b/src/vinylcontrol/vinylcontrolxwax.cpp
index e5cf9aef2c..38057244b6 100644
--- a/src/vinylcontrol/vinylcontrolxwax.cpp
+++ b/src/vinylcontrol/vinylcontrolxwax.cpp
@@ -63,6 +63,7 @@ VinylControlXwax::VinylControlXwax(ConfigObject<ConfigValue>* pConfig, QString g
           m_iPitchRingSize(0),
           m_iPitchRingPos(0),
           m_iPitchRingFilled(0),
+          m_dDisplayPitch(0.0),
           m_pSteadySubtle(new SteadyPitch(0.12)),
           m_pSteadyGross(new SteadyPitch(0.5)),
           m_bCDControl(false),
@@ -573,8 +574,26 @@ void VinylControlXwax::analyzeSamples(CSAMPLE* pSamples, size_t nFrames) {
 
         controlScratch->slotSet(averagePitch + dDriftControl);
         if (m_iPosition != -1 && reportedPlayButton && uiUpdateTime(filePosition)) {
-            rateSlider->slotSet(rateDir->get() *
-                                (fabs(averagePitch + dDriftControl) - 1.0) / rateRange->get());
+            double true_pitch = averagePitch + dDriftControl;
+            double pitch_diff_magnitude = fabs(true_pitch - m_dDisplayPitch);
+
+            // The true pitch can show a misleading amount of variance --
+            // differences of .1% or less can show up as 1 or 2 bpm changes.
+            // Therefore we react slowly to bpm changes to show a more steady
+            // number to the user.
+            if (pitch_diff_magnitude > 0.5) {
+                // For large changes in pitch (start/stop, usually), immediately
+                // update the display.
+                m_dDisplayPitch = true_pitch;
+            } else if (pitch_diff_magnitude > 0.005) {
+                // For medium changes in pitch, take 4 callback loops to
+                // converge on the correct amount.
+                m_dDisplayPitch += (true_pitch - m_dDisplayPitch) * .25;
+            } else {
+                // For extremely small changes, converge very slowly.
+                m_dDisplayPitch += (true_pitch - m_dDisplayPitch) * .01;
+            }
+            rateSlider->slotSet(rateDir->get() * (m_dDisplayPitch - 1.0) / rateRange->get());
             m_dUiUpdateTime = filePosition;
         }
 
diff --git a/src/vinylcontrol/vinylcontrolxwax.h b/src/vinylcontrol/vinylcontrolxwax.h
index 0a6a9c4a26..b7b1b39be1 100644
--- a/src/vinylcontrol/vinylcontrolxwax.h
+++ b/src/vinylcontrol/vinylcontrolxwax.h
@@ -96,6 +96,8 @@ class VinylControlXwax : public VinylControl {
     // How much of the pitch ring buffer is "filled" versus empty (used before
     // it fills up completely).
     int m_iPitchRingFilled;
+    // A smoothed pitch value to show to the user.
+    double m_dDisplayPitch;
 
     // Steady pitch trackers.
     SteadyPitch* m_pSteadySubtle;
diff --git a/src/waveform/renderers/waveformwidgetrenderer.cpp b/src/waveform/renderers/waveformwidgetrenderer.cpp
index 13f9e5ba73..6256adfca8 100644
--- a/src/waveform/renderers/waveformwidgetrenderer.cpp
+++ b/src/waveform/renderers/waveformwidgetrenderer.cpp
@@ -108,8 +108,23 @@ void WaveformWidgetRenderer::onPreRender(VSyncThread* vsyncThread) {
         return;
     }
 
-    //Fetch parameters before rendering in order the display all sub-renderers with the same values
-    m_rate = m_pRateControlObject->get();
+    // Fetch parameters before rendering in order the display all sub-renderers with the same values
+    double true_rate = m_pRateControlObject->get();
+    // We don't keep the waveform perfectly synced to the actual pitch to avoid
+    // unnecessary stretching of the waveform display.  Within a certain variance
+    // we don't change the stretch at all.  Once the threshold has been crossed
+    // we gradually stretch the waveform toward the new value.  This adds a small
+    // amount of lag in the UI.
+    double rate_diff_magnitude = fabs(true_rate - m_rate);
+    if (rate_diff_magnitude > 1.0) {
+        // If the difference is large, just immediately pop to the new value.
+        m_rate = true_rate;
+    } else if (rate_diff_magnitude > 0.05) {
+        // if the difference is small, converge slowly (10 updates to converge
+        // on the new value).
+        m_rate += (true_rate - m_rate) * 0.1;
+    } // if the difference is even smaller, don't change the display.
+
     m_rateDir = m_pRateDirControlObject->get();
     m_rateRange = m_pRateRangeControlObject->get();
     // This gain adjustment compensates for an arbitrary /2 gain chop in
diff --git a/src/widget/wnumber.cpp b/src/widget/wnumber.cpp
index 45c4f34c02..9e598857b0 100644
--- a/src/widget/wnumber.cpp
+++ b/src/widget/wnumber.cpp
@@ -53,11 +53,6 @@ void WNumber::onConnectedControlValueChanged(double v) {
 
 void WNumber::setValue(double dValue) {
     double v = dValue + m_dConstFactor;
-    int d1 = (int)floor((v-floor(v))*10.);
-    int d2 = (int)floor((v-floor(v))*100.)%10;
 
-    setText(QString(m_qsText).append("%1.%2%3").arg(
-        QString("%1").arg(static_cast<int>(v), 3, 10),
-        QString("%1").arg(d1, 1, 10),
-        QString("%1").arg(d2, 1, 10)));
+    setText(QString(m_qsText).append(QString::number(v, 'f', 1)));
 }
diff --git a/src/widget/wnumberrate.cpp b/src/widget/wnumberrate.cpp
index c9dee87374..2844a784b0 100644
--- a/src/widget/wnumberrate.cpp
+++ b/src/widget/wnumberrate.cpp
@@ -49,5 +49,5 @@ void WNumberRate::setValue(double) {
     }
 
     setText(QString(m_qsText).append(sign)
-            .append("%1").arg(fabs(vsign)*100., 0, 'f', 2));
+            .append("%1").arg(fabs(vsign)*100., 0, 'f', 1));
 }