Initial source commit

gamma256/gameSource/Envelope.h

@@ -0,0 +1,45 @@
+
+
+class Envelope {
+    public:
+        
+
+        /**
+         * Constructs an envelope.
+         *
+         * All parameters are in range 0..1, and sum of the three time
+         * parameters must be <= 1.
+         *
+         * @param inMaxNoteLengthInGridSteps the maximum note length to
+         *   cover.  Exact envelopes will be generated for notes up
+         *   to this length.
+         * @param inGridStepDurationInSamples the number of samples
+         *   per grid step. 
+         */ 
+        Envelope( double inAttackTime, double inDecayTime, 
+                  double inSustainLevel, double inReleaseTime,
+                  int inMaxNoteLengthInGridSteps,
+                  int inGridStepDurationInSamples );
+        
+        ~Envelope();
+
+        
+
+        /**
+         * Gets an evenlope for a given note length.
+         *
+         * @return an evelope of values in [0,1] that can be indexed by
+         *   sample number.  Will be destroyed when this class is destroyed.
+         */
+        double *getEnvelope( int inNoteLengthInGridSteps );
+        
+
+
+    private:
+        
+        int mNumComputedEnvelopes;
+        
+        int *mEvelopeLengths;
+        
+        double **mComputedEnvelopes;
+    };