From fce86b22a2367f1be1f9aae5e1ba3d18d1371b74 Mon Sep 17 00:00:00 2001
From: Michele Calgaro <michele.calgaro@yahoo.it>
Date: Tue, 8 Dec 2020 22:26:17 +0900
Subject: Renaming of files in preparation for code style tools.

Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>
---
 arts/modules/synth/synth_pitch_shift_impl.cpp | 196 ++++++++++++++++++++++++++
 1 file changed, 196 insertions(+)
 create mode 100644 arts/modules/synth/synth_pitch_shift_impl.cpp

(limited to 'arts/modules/synth/synth_pitch_shift_impl.cpp')

diff --git a/arts/modules/synth/synth_pitch_shift_impl.cpp b/arts/modules/synth/synth_pitch_shift_impl.cpp
new file mode 100644
index 00000000..37217c8a
--- /dev/null
+++ b/arts/modules/synth/synth_pitch_shift_impl.cpp
@@ -0,0 +1,196 @@
+/*
+
+    Copyright (C) 2000 Jeff Tranter
+                       tranter@pobox.com
+
+              (C) 1999 Stefan Westerfeld
+                       stefan@space.twc.de
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+    */
+
+#include <math.h>
+#include "artsmodulessynth.h"
+#include "stdsynthmodule.h"
+
+using namespace Arts;
+
+class Synth_PITCH_SHIFT_impl : virtual public Synth_PITCH_SHIFT_skel,
+							   virtual public StdSynthModule
+{
+protected:
+	float _speed, _frequency;
+
+	enum { MAXDELAY = 44100 };
+	float *dbuffer;
+	float lfopos, b1pos, b2pos, b1inc, b2inc;
+	bool b1reset, b2reset, initialized;
+	int dbpos;
+
+public:
+	Synth_PITCH_SHIFT_impl() : _speed(1.0), _frequency(5.0)
+	{
+	}
+
+	float speed() { return _speed; }
+	void speed(float newSpeed) { _speed = newSpeed; }
+
+	float frequency() { return _frequency; }
+	void frequency(float newFrequency) { _frequency = newFrequency; }
+
+
+	void streamInit()
+	{
+		dbuffer = new float[MAXDELAY];
+		for (dbpos=0; dbpos<MAXDELAY; dbpos++)
+			dbuffer[dbpos] = 0;
+
+		dbpos = 0;
+		initialized = false;
+		lfopos = 0;
+	}
+	void streamEnd()
+	{
+		delete[] dbuffer;
+	}
+
+	void calculateBlock(unsigned long samples)
+	{
+		float *outend = outvalue + samples;
+		float fsr = (float)samplingRate;
+		float pi2 = 2*M_PI;
+		float lfo, b1value, b2value;
+		float lfoposinc = _frequency / fsr;
+
+		if (!initialized)
+		{
+			if (_speed <= 1.0) {
+				b1pos = b2pos = 0.0;
+				b1inc = b2inc = 1.0 - _speed;
+			} else {
+				/* not yet sure what would be a nice initialization here? */
+				b1pos = b2pos = 0.0;
+				b1inc = b2inc = 0.0;
+			}
+			initialized = true;
+		}
+
+		while (outvalue < outend)
+		{
+			/*
+			 * fill delay buffer with the input signal
+			 */
+			dbuffer[dbpos] = *invalue++;
+
+			lfopos += lfoposinc;
+			lfopos -= floor(lfopos);
+
+			if (lfopos < 0.25) {
+				b1reset = b2reset = false;
+			}
+
+			/*
+			 * _speed < 1.0 (downpitching)
+			 *
+			 *  start with current sample and increase delay slowly
+			 *
+			 * _speed > 1.0 (uppitching)
+			 *
+			 *  start with a sample from long ago and slowly decrease delay
+			 */
+			if (!b1reset && lfopos > 0.25) {
+				if (_speed <= 1.0) {
+					b1pos = 0;
+					b1inc = 1 - _speed;
+				} else {
+					b1inc = 1 - _speed;
+					b1pos = 10 + ((-b1inc) * (1 / lfoposinc));
+					/* 10+ are not strictly necessary */
+				}
+				b1reset = true;
+			}
+
+			if (!b2reset && lfopos > 0.75) {
+				if (_speed <= 1.0) {
+					b2pos = 0;
+					b2inc = 1 - _speed;
+				} else{
+					b2inc = 1 - _speed;
+					b2pos = 10 + ((-b2inc) * (1/lfoposinc));
+					/* 10+ are not strictly necessary */
+				}
+				b2reset = true;
+			}
+
+			b1pos += b1inc;
+			b2pos += b2inc;
+
+			int position, position1;
+			double error,int_pos;
+
+			/*
+			 * Interpolate value from buffer position 1
+			 */
+			error = modf(b1pos, &int_pos);
+	
+			position = dbpos - (int)int_pos;
+			if (position < 0)
+				position += MAXDELAY;
+			position1 = position - 1;
+			if (position1 < 0)
+				position1 += MAXDELAY;
+
+			b1value = dbuffer[position] * (1 - error) + dbuffer[position1] * error;
+
+			/*
+			 * Interpolate value from buffer position 2
+			 */
+			error = modf(b2pos,&int_pos);
+	
+			position = dbpos - (int)int_pos;
+			if (position < 0)
+				position += MAXDELAY;
+			position1 = position-1;
+			if ( position1 < 0)
+				position1 += MAXDELAY;
+
+			b2value = dbuffer[position]*(1-error) + dbuffer[position1]*error;
+
+			/*
+			 * Calculate output signal from these two buffers
+			 */
+
+			lfo = (sin(pi2 * lfopos) + 1) / 2;
+
+			/*             position    sin   lfo variable
+			 *------------------------------------------------------------------
+			 * lfo value:    0.25       1         1        => buffer 2 is used
+			 *               0.75      -1         0        => buffer 1 is used
+			 */
+			
+			*outvalue++ = b1value * (1.0 - lfo) + b2value * lfo;
+			
+			/*
+			 * increment delay buffer position
+			 */
+			dbpos++;
+			if (dbpos == MAXDELAY)
+				dbpos = 0;
+		}
+	}
+};
+
+REGISTER_IMPLEMENTATION(Synth_PITCH_SHIFT_impl);
-- 
cgit v1.2.1