initial bring-up of the wave synth

issue #16

src/engine/waveSynth.h

@@ -29,16 +29,41 @@ class DivWaveSynth {
   DivEngine* e;
   DivInstrumentWaveSynth state;
   int pos, stage, divCounter, width, height;
-  bool first;
+  bool first, activeChangedB;
   unsigned char wave1[256];
   unsigned char wave2[256];
-  int output[256];
   public:
+    /**
+     * the output.
+     */
+    int output[256];
+    /**
+     * check whether the "active" status has changed.
+     * @return truth.
+     */
+    bool activeChanged();
     /**
      * tick this DivWaveSynth.
      * @return whether the wave has changed.
      */
     bool tick();
+    /**
+     * change the first wave.
+     * @param num wavetable number.
+     */
+    void changeWave1(int num);
+    /**
+     * change the second wave.
+     * @param num wavetable number.
+     */
+    void changeWave2(int num);
+    /**
+     * initialize this DivWaveSynth.
+     * @param which the instrument.
+     * @param width the system's wave width.
+     * @param height the system's wave height.
+     * @param insChanged whether the instrument has changed.
+     */
     void init(DivInstrument* which, int width, int height, bool insChanged=false);
     void setEngine(DivEngine* engine);
     DivWaveSynth():
@@ -48,7 +73,8 @@ class DivWaveSynth {
       divCounter(0),
       width(32),
       height(31),
-      first(false) {
+      first(false),
+      activeChangedB(false) {
       memset(wave1,0,sizeof(int)*256);
       memset(wave2,0,sizeof(int)*256);
       memset(output,0,sizeof(int)*256);