GUI M8e

gui/AudioLevelMeter.cpp

@@ -0,0 +1,90 @@
+#include "AudioLevelMeter.h"
+
+#include <QPainter>
+
+#include <algorithm>
+
+AudioLevelMeter::AudioLevelMeter(QWidget *parent) : QWidget(parent) {
+  setAutoFillBackground(false);
+  setAttribute(Qt::WA_OpaquePaintEvent);
+}
+
+void AudioLevelMeter::setLevel(float level) {
+  m_level = std::clamp(level, 0.0f, 1.0f);
+
+  if (m_level >= m_peakHold) {
+    m_peakHold = m_level;
+    m_peakHoldFrames = 0;
+  } else {
+    ++m_peakHoldFrames;
+    if (m_peakHoldFrames > kPeakHoldDuration) {
+      m_peakHold = std::max(0.0f, m_peakHold - kPeakDecayRate);
+    }
+  }
+
+  update();
+}
+
+float AudioLevelMeter::level() const { return m_level; }
+
+float AudioLevelMeter::peakHold() const { return m_peakHold; }
+
+void AudioLevelMeter::resetPeakHold() {
+  m_peakHold = 0.0f;
+  m_peakHoldFrames = 0;
+  update();
+}
+
+QSize AudioLevelMeter::sizeHint() const { return {40, 160}; }
+
+QSize AudioLevelMeter::minimumSizeHint() const { return {12, 40}; }
+
+void AudioLevelMeter::paintEvent(QPaintEvent *) {
+  QPainter painter(this);
+  painter.setRenderHint(QPainter::Antialiasing, false);
+
+  QRect r = rect();
+  painter.fillRect(r, QColor(24, 24, 28));
+
+  if (m_level <= 0.0f && m_peakHold <= 0.0f)
+    return;
+
+  int barHeight = static_cast<int>(m_level * r.height());
+  int barTop = r.height() - barHeight;
+
+  if (barHeight > 0) {
+    float greenEnd = 0.7f * r.height();
+    float yellowEnd = 0.9f * r.height();
+
+    int greenH = std::min(barHeight, static_cast<int>(greenEnd));
+    if (greenH > 0) {
+      painter.fillRect(r.left(), r.bottom() - greenH + 1, r.width(), greenH,
+                       QColor(76, 175, 80));
+    }
+
+    if (barHeight > static_cast<int>(greenEnd)) {
+      int yellowH =
+          std::min(barHeight - static_cast<int>(greenEnd),
+                   static_cast<int>(yellowEnd) - static_cast<int>(greenEnd));
+      if (yellowH > 0) {
+        painter.fillRect(r.left(), r.bottom() - static_cast<int>(greenEnd) - yellowH + 1,
+                         r.width(), yellowH, QColor(255, 193, 7));
+      }
+    }
+
+    if (barHeight > static_cast<int>(yellowEnd)) {
+      int redH = barHeight - static_cast<int>(yellowEnd);
+      if (redH > 0) {
+        painter.fillRect(r.left(), barTop, r.width(), redH,
+                         QColor(244, 67, 54));
+      }
+    }
+  }
+
+  if (m_peakHold > 0.0f) {
+    int peakY = r.height() - static_cast<int>(m_peakHold * r.height());
+    peakY = std::clamp(peakY, r.top(), r.bottom());
+    painter.setPen(QColor(255, 255, 255));
+    painter.drawLine(r.left(), peakY, r.right(), peakY);
+  }
+}