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Fix #3842: Opening a project with LB302 with specific waveforms produces a noise burst. #3844

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Merged
michaelgregorius merged 3 commits into from
Oct 1, 2017
Merged

Fix #3842: Opening a project with LB302 with specific waveforms produces a noise burst. #3844

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8ad46aa
Fix #3842: Opening a project with LB302 produces a noise burst
michaelgregorius Sep 30, 2017
08e840b
LB302: Move init of VCA members into constructor initializer list
michaelgregorius Sep 30, 2017
7d50a24
Introduce an enum to describe the VCA mode
michaelgregorius Sep 30, 2017
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39 changes: 15 additions & 24 deletions plugins/lb302/lb302.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -284,8 +284,12 @@ lb302Synth::lb302Synth( InstrumentTrack * _instrumentTrack ) :
slideToggle( false, this, tr( "Slide" ) ),
accentToggle( false, this, tr( "Accent" ) ),
deadToggle( false, this, tr( "Dead" ) ),
db24Toggle( false, this, tr( "24dB/oct Filter" ) )

db24Toggle( false, this, tr( "24dB/oct Filter" ) ),
vca_attack(1.0 - 0.96406088),
vca_decay(0.99897516),
vca_a0(0.5),
vca_a(0.),
vca_mode(never_played)
{

connect( Engine::mixer(), SIGNAL( sampleRateChanged( ) ),
Expand Down Expand Up @@ -327,21 +331,8 @@ lb302Synth::lb302Synth( InstrumentTrack * _instrumentTrack ) :

vcf_envpos = ENVINC;

// Start VCA on an attack.
vca_mode = 3;
vca_a = 0;

//vca_attack = 1.0 - 0.94406088;
vca_attack = 1.0 - 0.96406088;
vca_decay = 0.99897516;

vco_shape = BL_SAWTOOTH;

// Experimenting with a0 between original (0.5) and 1.0
vca_a0 = 0.5;
vca_a = 9;
vca_mode = 3;

vcfs[0] = new lb302FilterIIR2(&fs);
vcfs[1] = new lb302Filter3Pole(&fs);
db24Toggled();
Expand Down Expand Up @@ -481,7 +472,7 @@ int lb302Synth::process(sampleFrame *outbuf, const int size)

if( release_frame == 0 || ! m_playingNote )
{
vca_mode = 1;
vca_mode = decay;
}

if( new_freq )
Expand All @@ -505,7 +496,7 @@ int lb302Synth::process(sampleFrame *outbuf, const int size)
// start decay if we're past release
if( i >= release_frame )
{
vca_mode = 1;
vca_mode = decay;
}

// update vcf
Expand Down Expand Up @@ -645,18 +636,18 @@ int lb302Synth::process(sampleFrame *outbuf, const int size)
}

// Handle Envelope
if(vca_mode==0) {
if(vca_mode==attack) {
vca_a+=(vca_a0-vca_a)*vca_attack;
if(sample_cnt>=0.5*Engine::mixer()->processingSampleRate())
vca_mode = 2;
vca_mode = idle;
}
else if(vca_mode == 1) {
else if(vca_mode == decay) {
vca_a *= vca_decay;

// the following line actually speeds up processing
if(vca_a < (1/65536.0)) {
vca_a = 0;
vca_mode = 3;
vca_mode = never_played;
}
}

Expand All @@ -678,15 +669,15 @@ void lb302Synth::initNote( lb302Note *n)

// Always reset vca on non-dead notes, and
// Only reset vca on decaying(decayed) and never-played
if(n->dead == 0 || (vca_mode==1 || vca_mode==3)) {
if(n->dead == 0 || (vca_mode == decay || vca_mode == never_played)) {
//printf(" good\n");
sample_cnt = 0;
vca_mode = 0;
vca_mode = attack;
// LB303:
//vca_a = 0;
}
else {
vca_mode = 2;
vca_mode = idle;
}

initSlide();
Expand Down
9 changes: 8 additions & 1 deletion plugins/lb302/lb302.h
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Original file line number Diff line number Diff line change
Expand Up @@ -224,7 +224,14 @@ public slots:
vca_a; // Amplifier coefficient.

// Envelope State
int vca_mode; // 0: attack, 1: decay, 2: idle, 3: never played
enum VCA_Mode
{
attack = 0,
decay = 1,
idle = 2,
never_played = 3
};
VCA_Mode vca_mode;

// My hacks
int sample_cnt;
Expand Down