Initial source commit

gamma256/gameSource/Timbre.cpp

@@ -0,0 +1,158 @@
+#include "Timbre.h"
+
+#include "minorGems/util/stringUtils.h"
+
+#include <math.h>
+#include <stdio.h>
+
+
+double twelthRootOfTwo = pow( 2, 1.0/12 );
+
+// for major scale
+// W, W, H, W, W, W, H
+int halfstepMap[ 7 ] = { 0, 2, 4, 5, 7, 9, 11 };
+
+// minor scale
+// W,H,W,W,H,W,W
+//int halfstepMap[ 7 ] = { 0, 2, 3, 5, 7, 8, 10 };
+
+
+
+// gets frequency of note in our scale
+double getFrequency( double inBaseFrequency, int inScaleNoteNumber ) {
+    int octavesUp = inScaleNoteNumber / 7;
+    
+    int numHalfsteps = halfstepMap[ inScaleNoteNumber % 7 ] + octavesUp * 12;
+    
+    return inBaseFrequency * pow( twelthRootOfTwo, numHalfsteps );
+    }
+
+
+
+
+/*
+  Was used during testing
+
+#include "minorGems/sound/formats/aiff.h"
+
+int outputFileNumber = 0;
+
+
+// outputs a wave table as an AIFF
+void outputWaveTable( Sint16 *inTable, int inLength, int inSampleRate ) {
+    // generate the header
+    int headerSize;
+    unsigned char *aiffHeader =
+        getAIFFHeader( 1,
+                       16,
+                       inSampleRate,
+                       inLength, 
+                       &headerSize );
+
+    char *fileName = autoSprintf( "waveTable%d.aiff", outputFileNumber );
+    outputFileNumber++;
+    
+
+    FILE *aiffFile = fopen( fileName, "wb" );
+
+    delete [] fileName;
+    
+
+    //printf( "Header size = %d\n", headerSize );
+    
+    fwrite( aiffHeader, 1, headerSize, aiffFile );
+
+    delete [] aiffHeader;
+    
+    for( int i=0; i<inLength; i++ ) {
+        Sint16 val = inTable[i];
+        
+        unsigned char msb = val >> 8 & 0xFF;
+        unsigned char lsb = val && 0xFF;
+
+        fwrite( &msb, 1, 1, aiffFile );
+        fwrite( &lsb, 1, 1, aiffFile );
+        }
+    fclose( aiffFile );
+    
+    }
+*/
+
+
+
+
+Timbre::Timbre( int inSampleRate,
+                double inLoudness,
+                double inBaseFrequency,
+                int inNumWaveTableEntries, 
+                double( *inWaveFunction )( double ) )
+        : mNumWaveTableEntries( inNumWaveTableEntries ),
+          mWaveTable( new Sint16*[ inNumWaveTableEntries ] ),
+          mWaveTableLengths( new int[ inNumWaveTableEntries ] ) {
+
+    // build wave table for each possible pitch in image
+    
+    for( int i=0; i<mNumWaveTableEntries; i++ ) {
+        double freq = getFrequency( inBaseFrequency, i );
+        double period = 1.0 / freq;
+        
+        // wave table contains more than one period to more 
+        // accurately represent a signal with frequency freq
+        int tableLength = (int)( 5 * period * inSampleRate );
+        
+        mWaveTableLengths[i] = tableLength;
+        mWaveTable[i] = new Sint16[ tableLength ];
+
+        // store double samples in temp table so we can compute
+        // max value for normalization
+        double *tempTable = new double[ tableLength ];
+        double maxValue = 0;
+        
+        int s;
+        
+        for( s=0; s<tableLength; s++ ) {
+            double t = (double)s / (double)inSampleRate;
+            double waveValue = inWaveFunction( 2 * M_PI * t * freq );
+        
+            tempTable[s] = waveValue;
+            
+            // track max value
+            if( waveValue > maxValue ) {
+                maxValue = waveValue;
+                }
+            else if( -waveValue > maxValue ) {
+                maxValue = -waveValue;
+                }
+            }
+        
+        // now normalize and convert to int
+        for( s=0; s<tableLength; s++ ) {
+            double waveValue = tempTable[s] * inLoudness / maxValue;
+            
+            // convert to int
+            mWaveTable[i][s] = (Sint16)( 32767 * waveValue );
+            }
+        
+        delete [] tempTable;
+        
+                
+        mWaveTableLengths[i] = tableLength;
+        
+
+        // to examine waveforms for testing
+        // outputWaveTable( mWaveTable[i], tableLength, inSampleRate );
+        
+        }
+    }
+
+
+        
+Timbre::~Timbre() {
+    delete [] mWaveTableLengths;
+    
+    for( int i=0; i<mNumWaveTableEntries; i++ ) {
+        delete [] mWaveTable[i];
+        }
+    delete [] mWaveTable;
+    }
+