- initial import

git-svn-id: http://moon:8086/svn/software/trunk/projects/JaySynth@37 b431acfa-c32f-4a4a-93f1-934dc6c82436
2014-10-25 07:27:55 +00:00
commit 843c6e300c
75 changed files with 40248 additions and 0 deletions
@@ -0,0 +1,97 @@
+// --------------------------------------------------------------
+// --------------------------------------------------------------
+
+#include <string.h>
+#include <stdlib.h>
+#include <time.h>
+#include <math.h>
+
+#include "synth_defs.h"
+#include "sine.h"
+
+// --------------------------------------------------------------
+// internal funcs
+// --------------------------------------------------------------
+
+// --------------------------------------------------------------
+// Exported functions
+// --------------------------------------------------------------
+void Sine_Init(sine_gen_t *pObj, synth_float_t fs)
+{
+	Sine_SetFS(pObj, fs);
+	Sine_Prepare(pObj);
+}	
+
+void Sine_Free(sine_gen_t *pObj)
+{
+}
+
+void Sine_SetFS(sine_gen_t *pObj, synth_float_t fs)
+{
+	pObj->fs = SINE_OVERSAMPLING*fs;
+	pObj->pitch = -1;
+}
+
+void Sine_Reset(sine_gen_t *pObj, synth_float_t phase)
+{
+	pObj->y[0] = cos(2*pi*phase);
+	pObj->y[1] = sin(2*pi*phase);
+	pObj->fscale = 1;
+}
+
+void Sine_Start(sine_gen_t *pObj)
+{
+	pObj->pitch = -1;
+	pObj->CV_fm = -1;
+}
+
+void Sine_Prepare(sine_gen_t *pObj)
+{
+	Sine_Reset(pObj, (synth_float_t)rand()/RAND_MAX);
+}
+
+void Sine_Update(sine_gen_t *pObj)
+{
+	synth_float_t freq;
+	freq = pObj->fscale * pObj->pitch;
+	pObj->b = 2.0 * sin(freq*pi / pObj->fs);
+}
+
+synth_float_t Sine_Process_Scalar(sine_gen_t *pObj, synth_float_t pitch, synth_float_t CV_fm)
+{
+	int i;
+
+	synth_float_t a, phi;
+
+	// ToDo: amplitude drift correction
+	// y[0]^2 + y[1]^2 = a;
+
+	if (pObj->CV_fm != CV_fm)
+	{
+		pObj->CV_fm = CV_fm;
+		pObj->fscale = (synth_float_t)pow((synth_float_t)2, CV_fm);
+		Sine_Update(pObj);
+	}
+
+	if (pObj->pitch != pitch)
+	{
+		pObj->pitch = pitch;
+		Sine_Update(pObj);
+	}
+
+	for (i=0; i < SINE_OVERSAMPLING; i++)
+	{
+		pObj->y[0] = pObj->y[0] - pObj->b*pObj->y[1];
+		pObj->y[1] = pObj->y[1] + pObj->b*pObj->y[0];
+	}
+	
+	a = pObj->y[0]*pObj->y[0] + pObj->y[1]*pObj->y[1];
+	if (fabs(a - 1) > 0.5)
+	{
+		phi = atan2(pObj->y[0], pObj->y[1]);
+		pObj->y[0] = sin(phi);
+		pObj->y[1] = cos(phi);
+	}
+	return -pObj->y[0];
+}
+