From 8d0d68b7cca3a4c58268fa0822ca38bb1863dd19 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Thu, 29 Oct 2015 21:02:39 +0100
Subject: [PATCH] Add a peak display.

---
 glwidget.cpp     |  8 ++++++--
 mainwindow.cpp   |  4 +++-
 mixer.h          |  2 +-
 ui_mainwindow.ui | 36 +++++++++++++++++++++++++++++-------
 vumeter.cpp      |  1 +
 vumeter.h        |  2 ++
 6 files changed, 42 insertions(+), 11 deletions(-)

diff --git a/glwidget.cpp b/glwidget.cpp
index 2118ffe..075106a 100644
--- a/glwidget.cpp
+++ b/glwidget.cpp
@@ -48,8 +48,12 @@ void GLWidget::initializeGL()
 	static std::once_flag flag;
 	std::call_once(flag, [this]{
 		global_mixer = new Mixer(QGLFormat::toSurfaceFormat(format()));
-		global_mixer->set_audio_level_callback([this](float level){
-			global_vu_meter->set_level(level);
+		global_mixer->set_audio_level_callback([this](float level_lufs, float peak_db){
+			global_vu_meter->set_level(level_lufs);
+
+			char buf[256];
+			snprintf(buf, sizeof(buf), "%.1f", peak_db);
+			global_peak_display->setText(buf);
 		});
 		global_mixer->start();
 	});
diff --git a/mainwindow.cpp b/mainwindow.cpp
index 29a863b..0fc17b5 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -80,7 +80,9 @@ MainWindow::MainWindow()
 	connect(ui->preview1, SIGNAL(transition_names_updated(std::vector<std::string>)),
 	        this, SLOT(set_transition_names(std::vector<std::string>)));
 
-	global_vu_meter = ui->vu_meter;  // global_mixer does not exist yet, so need to delay the hookup.
+	// global_mixer does not exist yet, so need to delay the actual hookups.
+	global_vu_meter = ui->vu_meter;
+	global_peak_display = ui->peak_display;
 }
 
 void MainWindow::resizeEvent(QResizeEvent* event)
diff --git a/mixer.h b/mixer.h
index 5b82b4e..7a0bfa3 100644
--- a/mixer.h
+++ b/mixer.h
@@ -81,7 +81,7 @@ public:
 		output_channel[output].set_frame_ready_callback(callback);
 	}
 
-	typedef std::function<void(float)> audio_level_callback_t;
+	typedef std::function<void(float, float)> audio_level_callback_t;
 	void set_audio_level_callback(audio_level_callback_t callback)
 	{
 		audio_level_callback = callback;
diff --git a/ui_mainwindow.ui b/ui_mainwindow.ui
index c4a1d7c..3f0a211 100644
--- a/ui_mainwindow.ui
+++ b/ui_mainwindow.ui
@@ -138,14 +138,36 @@
          </layout>
         </item>
         <item>
-         <widget class="VUMeter" name="vu_meter" native="true">
-          <property name="minimumSize">
-           <size>
-            <width>20</width>
-            <height>0</height>
-           </size>
+         <layout class="QVBoxLayout" name="verticalLayout_4">
+          <property name="leftMargin">
+           <number>0</number>
           </property>
-         </widget>
+          <item>
+           <widget class="VUMeter" name="vu_meter" native="true">
+            <property name="sizePolicy">
+             <sizepolicy hsizetype="Preferred" vsizetype="Preferred">
+              <horstretch>0</horstretch>
+              <verstretch>1</verstretch>
+             </sizepolicy>
+            </property>
+            <property name="minimumSize">
+             <size>
+              <width>20</width>
+              <height>0</height>
+             </size>
+            </property>
+            <zorder>peak_display</zorder>
+            <zorder>peak_display</zorder>
+           </widget>
+          </item>
+          <item>
+           <widget class="QLabel" name="peak_display">
+            <property name="text">
+             <string>-0.0</string>
+            </property>
+           </widget>
+          </item>
+         </layout>
         </item>
        </layout>
       </item>
diff --git a/vumeter.cpp b/vumeter.cpp
index 27ffc5a..e56268a 100644
--- a/vumeter.cpp
+++ b/vumeter.cpp
@@ -19,6 +19,7 @@ int lufs_to_pos(float level_lu, int height)
 }  // namespace
 
 VUMeter *global_vu_meter = nullptr;
+QLabel *global_peak_display = nullptr;
 
 VUMeter::VUMeter(QWidget *parent)
 	: QWidget(parent)
diff --git a/vumeter.h b/vumeter.h
index f9be292..61fbf23 100644
--- a/vumeter.h
+++ b/vumeter.h
@@ -2,6 +2,7 @@
 #define VUMETER_H
 
 #include <QWidget>
+#include <QLabel>
 #include <QPaintEvent>
 
 #include <mutex>
@@ -27,5 +28,6 @@ private:
 };
 
 extern VUMeter *global_vu_meter;
+extern QLabel *global_peak_display;
 
 #endif
-- 
2.39.2