From 8b9c98a27187324a75a0c429002d5696c3c1579b Mon Sep 17 00:00:00 2001
From: Ahmet Inan <xdsopl@googlemail.com>
Date: Sun, 30 Nov 2014 14:10:49 +0100
Subject: [PATCH] moved phasor code to phasor.rsh

---
 app/src/main/rs/decoder.rs | 32 +++++++----------------------
 app/src/main/rs/phasor.rsh | 41 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 25 deletions(-)
 create mode 100644 app/src/main/rs/phasor.rsh

diff --git a/app/src/main/rs/decoder.rs b/app/src/main/rs/decoder.rs
index b167615..343a1ee 100644
--- a/app/src/main/rs/decoder.rs
+++ b/app/src/main/rs/decoder.rs
@@ -19,6 +19,7 @@ limitations under the License.
 
 #include "complex.rsh"
 #include "ema.rsh"
+#include "phasor.rsh"
 
 short *audio_buffer;
 uchar *value_buffer;
@@ -106,32 +107,16 @@ static complex_t dat_lowpass(complex_t input)
     return cema_cascade(output, input, ema_dat_a, filter_order);
 }
 
-static complex_t cnt_phasor, cnt_phasor_delta;
-static complex_t cnt_phasor_rotate()
-{
-    complex_t prev = cnt_phasor;
-    cnt_phasor = cmul(cnt_phasor, cnt_phasor_delta);
-    cnt_phasor = normalize(cnt_phasor);
-    return prev;
-}
-
-static complex_t dat_phasor, dat_phasor_delta;
-static complex_t dat_phasor_rotate()
-{
-    complex_t prev = dat_phasor;
-    dat_phasor = cmul(dat_phasor, dat_phasor_delta);
-    dat_phasor = normalize(dat_phasor);
-    return prev;
-}
-
+static phasor_t cnt_phasor;
 static complex_t cnt_ddc(float amp)
 {
-    return cnt_lowpass(amp * cnt_phasor_rotate());
+    return cnt_lowpass(amp * rotate(&cnt_phasor));
 }
 
+static phasor_t dat_phasor;
 static complex_t dat_ddc(float amp)
 {
-    return dat_lowpass(amp * dat_phasor_rotate());
+    return dat_lowpass(amp * rotate(&dat_phasor));
 }
 
 static float cnt_fmd_scale;
@@ -444,11 +429,8 @@ void initialize(float rate, int length, int width, int height)
     ema_cnt_a = ema_cascade_a(cnt_bandwidth, sample_rate, filter_order);
     ema_dat_a = ema_cascade_a(dat_bandwidth, sample_rate, filter_order);
 
-    cnt_phasor = complex(0.0f, 1.0f);
-    cnt_phasor_delta = cexp(complex(0.0f, -2.0f * M_PI * cnt_carrier / sample_rate));
-
-    dat_phasor = complex(0.0f, 1.0f);
-    dat_phasor_delta = cexp(complex(0.0f, -2.0f * M_PI * dat_carrier / sample_rate));
+    cnt_phasor = phasor(-cnt_carrier, sample_rate);
+    dat_phasor = phasor(-dat_carrier, sample_rate);
 
     cnt_fmd_scale = sample_rate / (M_PI * cnt_bandwidth);
     dat_fmd_scale = sample_rate / (M_PI * dat_bandwidth);
diff --git a/app/src/main/rs/phasor.rsh b/app/src/main/rs/phasor.rsh
new file mode 100644
index 0000000..6262fe2
--- /dev/null
+++ b/app/src/main/rs/phasor.rsh
@@ -0,0 +1,41 @@
+/*
+Copyright 2014 Ahmet Inan <xdsopl@googlemail.com>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+ */
+
+#ifndef PHASOR_RSH
+#define PHASOR_RSH
+
+#include "complex.rsh"
+
+typedef struct {
+    complex_t phasor, delta;
+} phasor_t;
+
+static phasor_t phasor(float freq, float rate)
+{
+    return (phasor_t){
+        complex(0.0f, 1.0f),
+        cexp(complex(0.0f, 2.0f * M_PI * freq / rate))
+    };
+}
+
+static inline complex_t rotate(phasor_t *phasor)
+{
+    complex_t prev = phasor->phasor;
+    phasor->phasor = normalize(cmul(phasor->phasor, phasor->delta));
+    return prev;
+}
+
+#endif
\ No newline at end of file