Fix up synth_tonesweep and the example to conform (more closely) to the naming conventions

examples/ToneSweep/ToneSweep.ino

 AudioControlSGTL5000 audioShield;
 
 
-int t_ampx = 20000;
+float t_ampx = 0.8;
 int t_lox = 10;
 int t_hix = 22000;
 // Length of time for the sweep in seconds
 
   Serial.println("setup done");
 
-  if(!myEffect.begin(t_ampx,t_lox,t_hix,t_timex)) {
+  if(!myEffect.play(t_ampx,t_lox,t_hix,t_timex)) {
     Serial.println("AudioSynthToneSweep - begin failed");
     while(1);
   }
   // wait for the sweep to end
-  while(myEffect.busy());
+  while(myEffect.isPlaying());
 
   // and now reverse the sweep
-  if(!myEffect.begin(t_ampx,t_hix,t_lox,t_timex)) {
+  if(!myEffect.play(t_ampx,t_hix,t_lox,t_timex)) {
     Serial.println("AudioSynthToneSweep - begin failed");
     while(1);
   }
   // wait for the sweep to end
-  while(myEffect.busy());
+  while(myEffect.isPlaying());
   Serial.println("Done");
 }
 

synth_tonesweep.cpp

 // Written by Pete (El Supremo) Feb 2014
 
 
-boolean AudioSynthToneSweep::begin(short t_amp,int t_lo,int t_hi,float t_time)
+boolean AudioSynthToneSweep::play(float t_amp,int t_lo,int t_hi,float t_time)
 {
   double tone_tmp;
   
 }
   tone_amp = 0;
   if(t_amp < 0)return false;
+  if(t_amp > 1)return false;
   if(t_lo < 1)return false;
   if(t_hi < 1)return false;
   if(t_hi >= 44100/2)return false;
   tone_hi = t_hi;
   tone_phase = 0;
 
-  tone_amp = t_amp;
-  // Limit the output amplitude to prevent aliasing
-  // until I can figure out why this "overtops"
-  // above 29000.
-  if(tone_amp > 29000)tone_amp = 29000;
+  tone_amp = t_amp * 32767.0;
+
   tone_tmp = tone_hi - tone_lo;
   tone_sign = 1;
   tone_freq = tone_lo*0x100000000LL;
 
 
 
-unsigned char AudioSynthToneSweep::busy(void)
+unsigned char AudioSynthToneSweep::isPlaying(void)
 {
   return(sweep_busy);
 }

synth_tonesweep.h

   AudioStream(0,NULL), sweep_busy(0)
   { }
 
-  boolean begin(short t_amp,int t_lo,int t_hi,float t_time);
+  boolean play(float t_amp,int t_lo,int t_hi,float t_time);
   virtual void update(void);
-  unsigned char busy(void);
+  unsigned char isPlaying(void);
 
 private:
   short tone_amp;