From f300a580a43a61c1dee34248c9ac8f3158b55fa1 Mon Sep 17 00:00:00 2001
From: "Rachel Fae Fox (foxiepaws)" <fox@foxiepa.ws>
Date: Thu, 31 Oct 2019 03:04:12 -0400
Subject: [PATCH] added new FM synth code. not yet tested

---
 src/synths/fm_2op.c  | 32 ++++++++++++++++++++++++++++++
 src/synths/fm_2op.h  | 47 ++++++++++++++++++++++++++++++++++++++++++++
 src/synths/fm_core.c | 27 +++++++++++++++++++++++++
 src/synths/fm_core.h | 31 +++++++++++++++++++++++++++++
 4 files changed, 137 insertions(+)
 create mode 100644 src/synths/fm_2op.c
 create mode 100644 src/synths/fm_2op.h
 create mode 100644 src/synths/fm_core.c
 create mode 100644 src/synths/fm_core.h

diff --git a/src/synths/fm_2op.c b/src/synths/fm_2op.c
new file mode 100644
index 0000000..1bdd2e5
--- /dev/null
+++ b/src/synths/fm_2op.c
@@ -0,0 +1,32 @@
+/*
+ * Filename:    fm_2op.c
+ *
+ * Description:
+ *
+ *
+ * Version:     
+ * Created:     Thu Oct 31 02:02:19 2019
+ * Revision:    None
+ * Author:      Rachel Fae Fox (foxiepaws),fox@foxiepa.ws
+ *
+ */
+
+#include "../common.h"
+#include "fm_2op.h"
+
+float fm2_process(struct FM2 *self, EngineState *t) {
+    self->Carrier.gate=self->gate;
+    self->Modulator.gate=self->gate;
+    switch (self->Algorithm) {
+    case _fm2_0:
+	__asm ("nop");
+	float v1 = (self->Carrier).run(&self->Carrier, t, 0.0);
+	float v2 = (self->Modulator).run(&self->Modulator, t, 0.0);
+	double z = (double) v1 + (double) v2 - ((double)v1*(double)v2);
+	return z;
+	break;
+    case _fm2_1:
+	return (self->Carrier).run(&self->Carrier, t, (self->Modulator).run(&self->Modulator,t,0.0));
+	break;
+    }
+}
diff --git a/src/synths/fm_2op.h b/src/synths/fm_2op.h
new file mode 100644
index 0000000..3c143e7
--- /dev/null
+++ b/src/synths/fm_2op.h
@@ -0,0 +1,47 @@
+/*
+ * Filename:    fm_2op.h
+ *
+ * Description:
+ *
+ *
+ * Version:     
+ * Created:     Thu Oct 31 02:02:19 2019
+ * Revision:    None
+ * Author:      Rachel Fae Fox (foxiepaws),fox@foxiepa.ws
+ *
+ */
+
+#ifndef _H_FM2OP
+#define _H_FM2OP
+#include "../common.h"
+#include "fm_core.h"
+
+typedef enum FM2_ALG {_fm2_0, _fm2_1 } FM2_Alg;
+/* FM Algorithms
+
+alg 0
+
+    [ out ]
+     |   |
+   [ 1] [ 2]-[fb] 
+
+alg 1 
+  [fb] -> [2]-> [1] -> [ out ] 
+*/
+typedef struct FM2 {
+    Operator Carrier;
+    Operator Modulator;
+    FM2_Alg Algorithm;
+    float freq;
+    float gate;
+    float(*process)(struct FM2 *, EngineState *);
+} FM2;
+
+float fm2_process(struct FM2 *, EngineState *);
+
+
+
+
+
+
+#endif
diff --git a/src/synths/fm_core.c b/src/synths/fm_core.c
new file mode 100644
index 0000000..d0d7232
--- /dev/null
+++ b/src/synths/fm_core.c
@@ -0,0 +1,27 @@
+/*
+ * Filename:    fm_core.c
+ *
+ * Description:
+ *
+ *
+ * Version:     
+ * Created:     Thu Oct 31 02:06:11 2019
+ * Revision:    None
+ * Author:      Rachel Fae Fox (foxiepaws),fox@foxiepa.ws
+ *
+ */
+
+#include "../common.h"
+#include "../utils/envelope.h"
+#include "fm_core.h"
+#include <math.h>
+
+float core_fm_run(Operator* self, EngineState * t,float phase) {
+    self->e.gate = self->gate;
+    float out = 0;
+    out = sin(2 * M_PI * t->t * (self->mul * self->freq) / 44100 + ((self->feedback_level > 0.0) ? self->feedback_buffer : phase));
+    out *= (self->level * self->e.process(&self->e,t));
+    self->feedback_buffer = out;
+    return out;
+}
+
diff --git a/src/synths/fm_core.h b/src/synths/fm_core.h
new file mode 100644
index 0000000..8dfed97
--- /dev/null
+++ b/src/synths/fm_core.h
@@ -0,0 +1,31 @@
+/*
+ * Filename:    fm_core.h
+ *
+ * Description:
+ *
+ *
+ * Version:     
+ * Created:     Thu Oct 31 02:06:11 2019
+ * Revision:    None
+ * Author:      Rachel Fae Fox (foxiepaws),fox@foxiepa.ws
+ *
+ */
+
+#ifndef _H_FM_CORE
+#define _H_FM_CORE
+#include "../common.h"
+#include "../utils/envelope.h"
+
+typedef struct Operator {
+    float level;
+    Envelope e;
+    bool gate;
+    float freq;
+    float mul;
+    float feedback_level;
+    float feedback_buffer;
+    float(*run)(struct Operator*,EngineState *,float);
+} Operator;
+float core_fm_run(Operator*, EngineState *,float);
+
+#endif