Add a stereo correlation meter.

[nageru] / vumeter.cpp

diff --git a/vumeter.cpp b/vumeter.cpp
index 27ffc5ae5a6b0c86eb14f0f218b7baa59552c1b0..9fca7ddc1c8712e5c214ff9b4bda313caf73018d 100644 (file)
--- a/vumeter.cpp
+++ b/vumeter.cpp
@@ -1,40 +1,30 @@
 #include <QPainter>
 
 #include "vumeter.h"
+#include "vu_common.h"
 
 using namespace std;
 
-namespace {
-
-int lufs_to_pos(float level_lu, int height)
+VUMeter::VUMeter(QWidget *parent)
+       : QWidget(parent)
 {
-       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;
-
-VUMeter::VUMeter(QWidget *parent)
-       : QWidget(parent)
+void VUMeter::resizeEvent(QResizeEvent *event)
 {
+       on_pixmap = QPixmap(width(), height());
+       QPainter on_painter(&on_pixmap);
+       draw_vu_meter(on_painter, -HUGE_VAL, HUGE_VAL, width(), height(), 0);
+
+       off_pixmap = QPixmap(width(), height());
+       QPainter off_painter(&off_pixmap);
+       draw_vu_meter(off_painter, -HUGE_VAL, -HUGE_VAL, width(), height(), 0);
 }
 
 void VUMeter::paintEvent(QPaintEvent *event)
 {
        QPainter painter(this);
 
-       painter.fillRect(0, 0, width(), height(), Qt::black);
-
-       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);
@@ -42,7 +32,10 @@ void VUMeter::paintEvent(QPaintEvent *event)
        }
 
        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);
+       int on_pos = lufs_to_pos(level_lu, height());
+       QRect off_rect(0, 0, width(), on_pos);
+       QRect on_rect(0, on_pos, width(), height() - on_pos);
+
+       painter.drawPixmap(off_rect, off_pixmap, off_rect);
+       painter.drawPixmap(on_rect, on_pixmap, on_rect);
 }