From 4b5b0fa4fa34de216b9853c61b1f7579e273d75c Mon Sep 17 00:00:00 2001
From: Tobias Doerffel <tobias.doerffel@gmail.com>
Date: Fri, 17 Jan 2014 19:35:14 +0100
Subject: [PATCH] FxMixer, FxMixerView: cache maximum peak until next display
 update

We lost short peaks because the display update rate usually is much lower
than the number of audio buffers processed per second which lead to lost
peaks. We mitigate this issue by caching the maximum peak value until the
next display update where it is reset.
---
 src/core/FxMixer.cpp    | 15 +++++++++++----
 src/gui/FxMixerView.cpp |  9 +++++----
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/src/core/FxMixer.cpp b/src/core/FxMixer.cpp
index 864364cf5..ba76a78c5 100644
--- a/src/core/FxMixer.cpp
+++ b/src/core/FxMixer.cpp
@@ -123,10 +123,17 @@ void FxMixer::processChannel( fx_ch_t _ch, sampleFrame * _buf )
 		{
 			m_fxChannels[_ch]->m_fxChain.startRunning();
 			m_fxChannels[_ch]->m_stillRunning = m_fxChannels[_ch]->m_fxChain.processAudioBuffer( _buf, f );
-			m_fxChannels[_ch]->m_peakLeft = engine::mixer()->peakValueLeft( _buf, f ) *
-												m_fxChannels[_ch]->m_volumeModel.value();
-			m_fxChannels[_ch]->m_peakRight = engine::mixer()->peakValueRight( _buf, f ) *
-												m_fxChannels[_ch]->m_volumeModel.value();
+			float peakLeft = engine::mixer()->peakValueLeft( _buf, f ) * m_fxChannels[_ch]->m_volumeModel.value();
+			float peakRight = engine::mixer()->peakValueRight( _buf, f ) * m_fxChannels[_ch]->m_volumeModel.value();
+
+			if( peakLeft > m_fxChannels[_ch]->m_peakLeft )
+			{
+				m_fxChannels[_ch]->m_peakLeft = peakLeft;
+			}
+			if( peakRight > m_fxChannels[_ch]->m_peakRight )
+			{
+				m_fxChannels[_ch]->m_peakRight = peakRight;
+			}
 		}
 		m_fxChannels[_ch]->m_used = true;
 	}
diff --git a/src/gui/FxMixerView.cpp b/src/gui/FxMixerView.cpp
index 8d1b124e0..02d5fb178 100644
--- a/src/gui/FxMixerView.cpp
+++ b/src/gui/FxMixerView.cpp
@@ -340,17 +340,18 @@ void FxMixerView::updateFaders()
 		const float fall_off = 1.2;
 		if( m->m_fxChannels[i]->m_peakLeft > opl )
 		{
-			m_fxChannelViews[i].m_fader->setPeak_L(
-					m->m_fxChannels[i]->m_peakLeft );
+			m_fxChannelViews[i].m_fader->setPeak_L( m->m_fxChannels[i]->m_peakLeft );
+			m->m_fxChannels[i]->m_peakLeft = 0;
 		}
 		else
 		{
 			m_fxChannelViews[i].m_fader->setPeak_L( opl/fall_off );
 		}
+
 		if( m->m_fxChannels[i]->m_peakRight > opr )
 		{
-			m_fxChannelViews[i].m_fader->setPeak_R(
-					m->m_fxChannels[i]->m_peakRight );
+			m_fxChannelViews[i].m_fader->setPeak_R( m->m_fxChannels[i]->m_peakRight );
+			m->m_fxChannels[i]->m_peakRight = 0;
 		}
 		else
 		{