Initial source commit

gamma256/gameSource/Envelope.cpp

@@ -0,0 +1,92 @@
+#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 ];
+    }
+
+