From 8693623758edfffa7e917660df1d251423edb29e Mon Sep 17 00:00:00 2001
From: Garrett <g@floft.net>
Date: Tue, 11 Nov 2014 09:39:24 -0800
Subject: [PATCH] Fixed resampling glitches when deleting notes

Moving the code to detect the sample rates of the currently used samples
after the code deleting notes seemed to fix these glitches. Also, fixed a
few ADSR issues that could have resulted in clipping in the attack or
glitching after the release.
---
 plugins/GigPlayer/GigPlayer.cpp | 56 +++++++++++++++------------------
 1 file changed, 26 insertions(+), 30 deletions(-)

diff --git a/plugins/GigPlayer/GigPlayer.cpp b/plugins/GigPlayer/GigPlayer.cpp
index 363ac3681..1df0303fe 100644
--- a/plugins/GigPlayer/GigPlayer.cpp
+++ b/plugins/GigPlayer/GigPlayer.cpp
@@ -391,10 +391,10 @@ void GigInstrument::play( sampleFrame * _working_buffer )
 			addSamples( *it, false );
 		}
 
+		// Delete ended samples
 		for( QList<GigSample>::iterator sample = it->samples.begin();
 				sample != it->samples.end(); ++sample )
 		{
-			// Delete ended samples
 			if( sample->sample == NULL || sample->adsr.done() ||
 					sample->pos >= sample->sample->SamplesTotal - 1 )
 			{
@@ -405,21 +405,6 @@ void GigInstrument::play( sampleFrame * _working_buffer )
 					break;
 				}
 			}
-			// Verify all the samples have the same rate
-			else
-			{
-				int currentRate = sample->sample->SamplesPerSecond;
-
-				if( oldRate == -1 )
-				{
-					oldRate = currentRate;
-				}
-				else if( oldRate != currentRate )
-				{
-					qCritical() << "GigInstrument: not all samples are the same rate, not converting";
-					sampleError = true;
-				}
-			}
 		}
 
 		// Delete ended notes (either in the completed state or all the samples ended)
@@ -432,6 +417,23 @@ void GigInstrument::play( sampleFrame * _working_buffer )
 				break;
 			}
 		}
+
+		// Verify all the samples have the same rate
+		for( QList<GigSample>::iterator sample = it->samples.begin();
+				sample != it->samples.end(); ++sample )
+		{
+			int currentRate = sample->sample->SamplesPerSecond;
+
+			if( oldRate == -1 )
+			{
+				oldRate = currentRate;
+			}
+			else if( oldRate != currentRate )
+			{
+				qCritical() << "GigInstrument: not all samples are the same rate, not converting";
+				sampleError = true;
+			}
+		}
 	}
 
 	// If all samples have the same sample rate and it's not the output sample
@@ -863,7 +865,7 @@ bool GigInstrument::convertSampleRate( sampleFrame & oldBuf, sampleFrame & newBu
 		return false;
 	}
 
-	if( src_data.output_frames_gen == 0 )
+	if( oldSize != 0 && src_data.output_frames_gen == 0 )
 	{
 		qCritical( "GigInstrument: could not resample, no frames generated" );
 		return false;
@@ -1183,7 +1185,7 @@ double ADSR::value()
 	{
 		if( attackPosition < attackLength )
 		{
-			amplitude = preattack + ( attack - preattack ) / attackLength * attackPosition;
+			amplitude = preattack + ( 1.0 - preattack ) / attackLength * attackPosition;
 		}
 		else if( attackPosition < attackLength + decayLength )
 		{
@@ -1199,20 +1201,14 @@ double ADSR::value()
 	// If we're in the sustain phase, decrease from sustain to zero
 	else if( isRelease == true )
 	{
-		if( releasePosition < releaseLength )
-		{
-			// Maybe not the best way of doing this, but it appears to be about right
-			amplitude = sustain * exp( -5.0 / releaseLength * releasePosition ) - 1e-5;
+		// Maybe not the best way of doing this, but it appears to be about right
+		// Satisfies f(0) = sustain and f(releaseLength) = very small
+		amplitude = ( sustain + 1e-3 ) * exp( -5.0 / releaseLength * releasePosition ) - 1e-3;
 
-			// Don't have an infinite exponential decay
-			if( amplitude < 0 )
-			{
-				amplitude = 0;
-				isDone = true;
-			}
-		}
-		else
+		// Don't have an infinite exponential decay
+		if( amplitude < 0 )
 		{
+			amplitude = 0;
 			isDone = true;
 		}