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#include "Envelope.h"
#include <stdio.h>
// #include <assert.h>
Envelope::Envelope( double inAttackTime, double inDecayTime,
double inSustainLevel, double inReleaseTime,
int inMaxNoteLengthInGridSteps,
int inGridStepDurationInSamples )
: mNumComputedEnvelopes( inMaxNoteLengthInGridSteps ),
mEvelopeLengths( new int[ inMaxNoteLengthInGridSteps ] ),
mComputedEnvelopes( new double*[ inMaxNoteLengthInGridSteps ] ) {
for( int i=0; i<mNumComputedEnvelopes; i++ ) {
int length = (i+1) * inGridStepDurationInSamples;
mEvelopeLengths[i] = length;
mComputedEnvelopes[i] = new double[ length ];
for( int s=0; s<length; s++ ) {
double t = s / (double)( length - 1 );
if( t < inAttackTime ) {
// assert( inAttackTime > 0 );
mComputedEnvelopes[i][s] = t / inAttackTime;
}
else if( t < inAttackTime + inDecayTime ) {
// assert( inDecayTime > 0 );
// decay down to sustain level
mComputedEnvelopes[i][s] =
( 1.0 - inSustainLevel ) *
( inAttackTime + inDecayTime - t ) /
( inDecayTime )
+ inSustainLevel;
}
else if( 1.0 - t > inReleaseTime ) {
mComputedEnvelopes[i][s] = inSustainLevel;
}
else {
if( inReleaseTime > 0 ) {
mComputedEnvelopes[i][s] =
inSustainLevel -
inSustainLevel *
( inReleaseTime - ( 1.0 - t ) ) / inReleaseTime;
}
else {
// release time 0
// hold sustain until end
mComputedEnvelopes[i][s] = inSustainLevel;
}
}
}
// test code to output evelopes for plotting in gnuplot
if( false && i == 0 ) {
FILE *file = fopen( "env0.txt", "w" );
for( int s=0; s<length; s++ ) {
fprintf( file, "%f %f\n",
s / (double)( length - 1 ),
mComputedEnvelopes[i][s] );
}
fclose( file );
}
}
}
Envelope::~Envelope() {
for( int i=0; i<mNumComputedEnvelopes; i++ ) {
delete [] mComputedEnvelopes[i];
}
delete [] mEvelopeLengths;
delete [] mComputedEnvelopes;
}
double *Envelope::getEnvelope( int inNoteLengthInGridSteps ) {
return mComputedEnvelopes[ inNoteLengthInGridSteps - 1 ];
}
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