1 files changed, 112 insertions, 0 deletions
diff --git a/src/engine/Problem.cpp b/src/engine/Problem.cpp
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--- /dev/null
+++ b/src/engine/Problem.cpp
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+/* This file is part of Machina.
+ * Copyright (C) 2007 Dave Robillard <http://drobilla.net>
+ * 
+ * Machina 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.
+ * 
+ * Machina 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 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 St, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+#include <iostream>
+#include <machina/Problem.hpp>
+#include <machina/Machine.hpp>
+#include <raul/SMFReader.hpp>
+#include <raul/midi_events.h>
+
+using namespace std;
+
+namespace Machina {
+
+	
+Problem::Problem(const std::string& target_midi)
+	: _target(*this)
+{
+	Raul::SMFReader smf;
+	const bool opened = smf.open(target_midi);
+	assert(opened);
+	
+	smf.seek_to_track(2); // FIXME: kluge
+	
+	uint8_t  buf[4];
+	uint32_t ev_size;
+	uint32_t delta_time;
+	while (smf.read_event(4, buf, &ev_size, &delta_time) >= 0) {
+		if ((buf[0] & 0xF0) == MIDI_CMD_NOTE_ON) {
+			const uint8_t note = buf[1];
+			++_target._note_frequency[note];
+			++_target._n_notes;
+		}
+	}
+
+	_target.compute();
+}
+
+
+float
+Problem::fitness(Machine& machine)
+{
+	SharedPtr<Evaluator> eval(new Evaluator(*this));
+
+	machine.reset(0.0f);
+	machine.set_sink(eval);
+
+	// FIXME: timing stuff here isn't right at all...
+	
+	unsigned ppqn = 19200;
+	Raul::TimeSlice time(ppqn, 120);
+	time.set_start(0);
+	time.set_length(ppqn);
+
+	while (time.start_ticks() < _target._n_notes * ppqn) {
+		machine.run(time);
+		time.set_start(time.start_ticks() + ppqn);
+	}
+
+	eval->compute();
+
+	float f = 0;
+
+	// Punish for frequency differences.
+	// Optimal fitness = 0 (max)
+	for (uint8_t i=0; i < 128; ++i)
+		f -= fabs(_target._note_frequency[i] - eval->_note_frequency[i]);
+
+	return f;
+}
+	
+
+void
+Problem::Evaluator::write_event(Raul::BeatTime time,
+                                size_t         ev_size,
+                                const uint8_t* ev) throw (std::logic_error)
+{
+	if ((ev[0] & 0xF0) == MIDI_CMD_NOTE_ON) {
+		const uint8_t note = ev[1];
+		++_note_frequency[note];
+		++_n_notes;
+	}
+}
+
+
+void
+Problem::Evaluator::compute()
+{
+	for (uint8_t i=0; i < 128; ++i) {
+		if (_note_frequency[i] > 0) {
+			_note_frequency[i] /= (float)_n_notes;
+			//cout << (int)i << ":\t" << _note_frequency[i] << endl;
+		}
+	}
+}
+
+
+} // namespace Machina
+