SparrowOSTS_121127.ISO

SparrowOS/Demo/Snd/PolyPhonic.CPP

@@ -0,0 +1,98 @@
+Bool poly_done;
+I64 start_buf_num;
+U0 (*fp_task_end_cb)();
+U0 (*fp_old_fill_buf)(SND_OUT_CONTAINER *buf,I64 buf_num)=NULL;
+
+U0 PolyFillBuf(SND_OUT_CONTAINER *buf,I64 buf_num)
+{ //Gets called by HD Audio task -- $LK,"HDAudioTask","MN:HDAudioTask"$().
+
+//Note: the buffer is in uncached memory
+//so you might want to avoid multiple
+//accesses due to slow speed.  (If you were
+//to add a bunch of waveforms together, you
+//might want to do it in a cached buffer
+//and copy it once.)
+
+  I64 j,m,r;
+  F64 t,d;
+  if (poly_done) return;
+  t=ToF64((buf_num-start_buf_num)*(SND_BUF_LEN/SND_OCHANNELS))/SND_SAMPLE_RATE;
+  j=0;
+  while (j<SND_BUF_LEN) {
+    d=0.5*Sin(1.0*(2*ã)*t)+0.5;  //Stereo pos from 0.0-1.0
+    r=RandI32;
+    m=0;
+ 
+    m+=0.2*MAX_I32*Caw(t,0.25)*Sin(220.0*(2*ã)*t);
+    m+=0.2*MAX_I32*Caw(t,0.25)*Sin(222.0*(2*ã)*t);
+    m+=0.2*MAX_I32*Caw(t,0.25)*Sin(880.0*(2*ã)*t);
+    m+=0.2*MAX_I32*Caw(t,0.25)*Sin(884.0*(2*ã)*t);
+    m+=0.4*r*Caw(t,.125);
+    if (Caw(t-.25,0.5)<=0.05)
+      m+=0.3*r*Caw(t,0.05);
+    if (t>4.0) {
+      if (0.90<Caw(t,1.0))
+	m+=0.6*MAX_I32*Caw(t,0.1)*FullCaw(t,0.001);
+      if (t>8.0) {
+	if (0.70<Caw(t,1.0)<0.90)
+	  m+=0.4*MAX_I32*Caw(t-.7,0.5)*FullCaw(t,0.00075);
+	if (t>12.0) {
+	  if (0.30<Caw(t,1.0)<0.40)
+	    m+=0.4*MAX_I32*Sin(100.0/(1.1-Saw(t,0.01)));
+	  if (t>16.0)
+	    m+=0.3*MAX_I32*Caw(t,1.0/6)*Sin(440.0*(2*ã)*t);
+	}
+      }
+    }
+
+    //Samples are 24-bit, placed in upper 24 bits of an I32.
+    m*=snd_vol;
+    buf[j++]=ToI64(m*d)&0xFFFFFF00;		//Left
+    buf[j++]=ToI64(m*(1.0-d))&0xFFFFFF00;	//Right
+
+    t+=1.0/SND_SAMPLE_RATE;
+  }
+}
+
+U0 PolyTaskEndCB()
+{
+  poly_done=TRUE;
+  fp_snd_fill_buf=fp_old_fill_buf;
+  if (fp_task_end_cb)
+    (*fp_task_end_cb)();
+  else
+    Exit;
+}
+
+U0 PolyPhonic()
+{
+  if (snd_dev!=SD_HD_AUDIO) {
+    "Only works for HD Audio.\n";
+    return;
+  }
+  poly_done=FALSE;
+  fp_task_end_cb=Fs->task_end_cb;
+  Fs->task_end_cb=&PolyTaskEndCB; //Catch <CTRL-ALT-X> or Kill() task
+  start_buf_num=snd_obuf_num;
+  fp_old_fill_buf=fp_snd_fill_buf;
+  fp_snd_fill_buf=&PolyFillBuf;
+  try
+#if IncludeDepth<2
+    PressAKey;
+#else
+    View;
+#endif
+  catch { //Catch <CTRL-ALT-C>, but pass it on to next higher handler.
+    fp_snd_fill_buf=fp_old_fill_buf;
+    Fs->task_end_cb=fp_task_end_cb;
+  }
+  poly_done=TRUE;
+  fp_snd_fill_buf=fp_old_fill_buf;
+  Fs->task_end_cb=fp_task_end_cb;
+}
+
+//This is so I can use this file stand alone
+//or as a component of a program.
+#if IncludeDepth<2
+PolyPhonic;
+#endif