Offload most Midi processing from Song into MidiTime class

include/MidiTime.h

@@ -27,8 +27,10 @@
 #ifndef MIDI_TIME_H
 #define MIDI_TIME_H
 
-#include "lmms_basics.h"
+#include <QtGlobal>
+
 #include "export.h"
+#include "lmms_basics.h"
 
 // note: 1 "Tact" = 1 Measure
 const int DefaultTicksPerTact = 192;
@@ -36,6 +38,25 @@ const int DefaultStepsPerTact = 16;
 const int DefaultBeatsPerTact = DefaultTicksPerTact / DefaultStepsPerTact;
 
 
+class MeterModel;
+
+class EXPORT TimeSig
+{
+public:
+	// in a time signature,
+	// the numerator represents the number of beats in a measure.
+	// the denominator indicates which type of note represents a beat.
+	// example: 6/8 means 6 beats in a measure, where each beat has duration equal to one 8th-note.
+	TimeSig( int num, int denom );
+	TimeSig( const MeterModel &model );
+	int numerator() const;
+	int denominator() const;
+private:
+	int m_num;
+	int m_denom;
+};
+
+
 class EXPORT MidiTime
 {
 public:
@@ -112,6 +133,26 @@ public:
 		return m_ticks;
 	}
 
+	tick_t ticksPerBeat( const TimeSig &sig ) const
+	{
+		return ticksPerTact(sig) / sig.numerator();
+	}
+	// Remainder ticks after bar is removed
+	tick_t getTickWithinBar( const TimeSig &sig ) const
+	{
+		return m_ticks % ticksPerTact(sig);
+	}
+	// Returns the beat position inside the bar, 0-based
+	tick_t getBeatWithinBar( const TimeSig &sig ) const
+	{
+		return getTickWithinBar(sig) / ticksPerBeat(sig);
+	}
+	// Remainder ticks after bar and beat are removed
+	tick_t getTickWithinBeat( const TimeSig &sig ) const
+	{
+		return getTickWithinBar(sig) % ticksPerBeat(sig);
+	}
+
 	// calculate number of frame that are needed this time
 	f_cnt_t frames( const float framesPerTick ) const
 	{
@@ -132,6 +173,10 @@ public:
 	{
 		return s_ticksPerTact;
 	}
+	static tick_t ticksPerTact( const TimeSig &sig ) const
+	{
+		return DefaultTicksPerTact * sig.numerator() / sig.denominator();
+	}
 
 	static int stepsPerTact()
 	{

include/Song.h

@@ -111,22 +111,18 @@ public:
 
 	inline int ticksPerTact() const
 	{
-		return DefaultTicksPerTact *
-				m_timeSigModel.getNumerator() /
-					 m_timeSigModel.getDenominator();
+		return MidiTime::ticksPerTact(m_timeSigModel);
 	}
 
 	// Returns the beat position inside the bar, 0-based
 	inline int getBeat() const
 	{
-		return ( currentTick() - currentTact() * ticksPerTact() ) /
-			( ticksPerTact() / m_timeSigModel.getNumerator() );
+		return getPlayPos().getBeatWithinBar(m_timeSigModel);
 	}
 	// the remainder after bar and beat are removed
 	inline int getBeatTicks() const
 	{
-		return 	( currentTick() - currentTact() * ticksPerTact() ) %
-			( ticksPerTact() / m_timeSigModel.getNumerator() );
+		return getPlayPos().getTickWithinBeat(m_timeSigModel);
 	}
 	inline int getTicks() const
 	{
@@ -186,6 +182,10 @@ public:
 	{
 		return m_playPos[pm];
 	}
+	inline const PlayPos & getPlayPos() const
+	{
+		return getPlayPos(m_playMode);
+	}
 
 	void updateLength();
 	tact_t length() const

src/core/CMakeLists.txt

@@ -82,6 +82,7 @@ set(LMMS_SRCS
 	core/midi/MidiController.cpp
 	core/midi/MidiOss.cpp
 	core/midi/MidiPort.cpp
+	core/midi/MidiTime.cpp
 	core/midi/MidiWinMM.cpp
 
 	PARENT_SCOPE

src/core/midi/MidiTime.cpp

@@ -0,0 +1,49 @@
+/*
+ * MidiTime.cpp - Class that encapsulates the position of a note/event in terms of
+ *   its bar, beat and tick.
+ *
+ * Copyright (c) 2004-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net
+ *
+ * This file is part of LMMS - http://lmms.io
+ *
+ * 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 (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include "MidiTime.h"
+
+#include "MeterModel.h"
+
+TimeSig::TimeSig( int num, int denom ) :
+	m_num(num),
+	m_denom(denom)
+{
+}
+
+TimeSig::TimeSig( const MeterModel &model ) :
+	m_num(model.getNumerator()),
+	m_denom(model.getDenominator())
+{
+}
+
+int TimeSig::numerator() const
+{
+	return m_num;
+}
+int TimeSig::denominator() const
+{
+	return m_denom;
+}