Add a peak display.

[nageru] / vumeter.cpp

diff --git a/vumeter.cpp b/vumeter.cpp
index 03a93e7ba4fd52476978cdb3759bce2a9b417b29..e56268ad46f0d6cddde59ba5d15b8134d9f411e7 100644 (file)
--- a/vumeter.cpp
+++ b/vumeter.cpp
@@ -4,7 +4,22 @@
 
 using namespace std;
 
+namespace {
+
+int lufs_to_pos(float level_lu, int height)
+{
+       const float min_level = 18.0f;    // y=0 is top of screen, so “min” is the loudest level.
+       const float max_level = -36.0f;
+       int y = lrintf(height * (level_lu - min_level) / (max_level - min_level));
+       y = std::max(y, 0);
+       y = std::min(y, height - 1);
+       return y;
+}
+
+}  // namespace
+
 VUMeter *global_vu_meter = nullptr;
+QLabel *global_peak_display = nullptr;
 
 VUMeter::VUMeter(QWidget *parent)
        : QWidget(parent)
@@ -17,17 +32,18 @@ void VUMeter::paintEvent(QPaintEvent *event)
 
        painter.fillRect(0, 0, width(), height(), Qt::black);
 
-       float level;
+       int min_y = lufs_to_pos(1.0f, height());
+       int max_y = lufs_to_pos(-1.0f, height());
+       painter.fillRect(0, min_y, width(), max_y - min_y, Qt::green);
+
+       float level_lufs;
        {
                unique_lock<mutex> lock(level_mutex);
-               level = this->level;
+               level_lufs = this->level_lufs;
        }
 
-       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);
-       }
+       float level_lu = level_lufs + 23.0f;
+       int y = lufs_to_pos(level_lu, height());
+       painter.setPen(Qt::white);
+       painter.drawLine(0, y, width(), y);
 }