Diff: PluckedGuitar.cpp

Revision:

0:ce6724069f0a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PluckedGuitar.cpp	Wed Jan 09 22:46:12 2013 +0000
@@ -0,0 +1,62 @@
+/* 
+ * libmbed-synth An audio synthesis library capable of running
+ * alongside other activities. 
+ * Copyright (C) <2009> Michael Sheldon <mike@mikeasoft.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+*/
+
+#include "PluckedGuitar.h"
+#include "mbed.h"
+
+PluckedGuitar::PluckedGuitar() :
+        Instrument::Instrument() {
+    _decay = 1.1;
+}
+
+void PluckedGuitar::note(Note note) {
+    _num_samples = _samplerate / note.frequency; 
+    _duration = ((_samplerate * 60) / _bpm) * note.duration;
+    _samples = (float *) malloc(_num_samples * sizeof(float));
+    int i;
+    _samples_played = 0;
+    _position = 0;
+    
+    for (i = 0; i < _num_samples; i++) {
+        _samples[i] = abs(sin((float) rand()));
+    }
+}
+
+float PluckedGuitar::proc_sample() {
+    DigitalOut l(LED2);
+    if (_position == _num_samples) {
+        _position = 0;
+    }
+    if (_samples_played > _duration) {
+        l = 1;
+        return -1;
+    }
+    if(_position == 0) {
+        _samples[0] = _samples[_num_samples - 1] + (_samples[0] - _samples[_num_samples - 1]) / _decay;    
+    } else {
+        _samples[_position] = _samples[_position-1] + (_samples[_position] - _samples[_position - 1]) / _decay;
+    }
+    float sample = _samples[_position];
+    
+    _samples_played++;
+    _position++;
+    return sample;
+}
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