+#include <QPainter>
+
+#include "vumeter.h"
+
+using namespace std;
+
+VUMeter *global_vu_meter = nullptr;
+
+VUMeter::VUMeter(QWidget *parent)
+ : QWidget(parent)
+{
+}
+
+void VUMeter::paintEvent(QPaintEvent *event)
+{
+ QPainter painter(this);
+
+ painter.fillRect(0, 0, width(), height(), Qt::black);
+
+ float level;
+ {
+ unique_lock<mutex> lock(level_mutex);
+ level = this->level;
+ }
+
+ const float min_level = 0.0f; // y=0 is top of screen, so “min” is the loudest level.
+ const float max_level = -60.0f;
+ int y = lrintf(height() * (level - min_level) / (max_level - min_level));
+ if (y >= 0 && y < height()) {
+ painter.setPen(Qt::white);
+ painter.drawLine(0, y, width(), y);
+ }
+}