the actual average BPM code

HertzDevil · Jun 6, 2016 · 0577dda · 0577dda
1 parent 915e39e
commit 0577dda
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Showing 2 changed files with 37 additions and 1 deletion.
diff --git a/Source/SoundGen.cpp b/Source/SoundGen.cpp
@@ -142,7 +142,8 @@ CSoundGen::CSoundGen() :
 	m_iClipCounter(0),
 	m_pSequencePlayPos(NULL),
 	m_iSequencePlayPos(0),
-	m_iSequenceTimeout(0)
+	m_iSequenceTimeout(0),
+	m_iBPMCachePosition(0)		// // //
 {
 	TRACE("SoundGen: Object created\n");
 
@@ -1082,6 +1083,16 @@ void CSoundGen::BeginPlayer(play_mode_t Mode, int Track)
 	std::queue<int>().swap(m_iRegisterStream);
 #endif
 
+	{		// // // 050B
+		m_iRowTickCount = 0;
+
+		float Tempo = GetTempo();
+		for (auto &x : m_fBPMCacheValue)
+			x = Tempo;
+		for (auto &x : m_iBPMCacheTicks)
+			x = 1;
+	}
+
 	ResetTempo();
 	ResetAPU();
 
@@ -1466,6 +1477,17 @@ float CSoundGen::GetTempo() const
 	return !m_iSpeed ? 0 : float(Tempo * 6) / Speed;
 }
 
+float CSoundGen::GetAverageBPM() const
+{
+	float BPMtot = 0.f;
+	float TickTot = 0.f;
+	for (int i = 0; i < AVERAGE_BPM_SIZE; ++i)
+		BPMtot += m_fBPMCacheValue[i] * m_iBPMCacheTicks[i];
+	for (const auto &x : m_iBPMCacheTicks)
+		TickTot += x;
+	return static_cast<float>(BPMtot / TickTot);
+}
+
 void CSoundGen::RunFrame()
 {
 	// Called from player thread
@@ -1500,6 +1522,7 @@ void CSoundGen::RunFrame()
 		}
 #endif /* EXPORT_TEST */
 
+		++m_iRowTickCount;		// // // 050B
 		m_iStepRows = 0;
 
 		// Fetch next row
@@ -1517,6 +1540,12 @@ void CSoundGen::RunFrame()
 			m_bUpdateRow = true;
 			ReadPatternRow();
 			++m_iRenderRow;
+
+			// // // 050B
+			m_fBPMCacheValue[m_iBPMCachePosition] = GetTempo();		// // // 050B
+			m_iBPMCacheTicks[m_iBPMCachePosition] = m_iRowTickCount;
+			m_iRowTickCount = 0;
+			++m_iBPMCachePosition %= AVERAGE_BPM_SIZE;
 		}
 		else {
 			m_bUpdateRow = false;

diff --git a/Source/SoundGen.h b/Source/SoundGen.h
@@ -152,6 +152,7 @@ class CSoundGen : public CWinThread, IAudioCallback
 	void		 ResetState();
 	void		 ResetTempo();
 	float		 GetTempo() const;
+	float		 GetAverageBPM() const;		// // //
 	bool		 IsPlaying() const { return m_bPlaying; };
 
 	// Stats
@@ -359,6 +360,7 @@ class CSoundGen : public CWinThread, IAudioCallback
 	int					m_iSkipToRow;
 	bool				m_bDoHalt;							// // // Cxx effect
 	int					m_iStepRows;						// # of rows skipped last update
+	int					m_iRowTickCount;					// // // 050B
 	play_mode_t			m_iPlayMode;
 
 	unsigned int		m_iNoteLookupTableNTSC[96];			// For 2A03
@@ -388,6 +390,11 @@ class CSoundGen : public CWinThread, IAudioCallback
 	int					m_iTempoRemainder;
 	bool				m_bUpdateRow;
 
+	static const int	AVERAGE_BPM_SIZE = 24;		// // // 050B
+	float				m_fBPMCacheValue[AVERAGE_BPM_SIZE];
+	int					m_iBPMCacheTicks[AVERAGE_BPM_SIZE];
+	int					m_iBPMCachePosition;
+
 	std::queue<int>		m_iRegisterStream;					// // // vgm export
 
 	CWaveFile			m_wfWaveFile;