[Ref] Make ModInstrument constexpr-constructable. This will allow an instrument extension writer implementation without a global constant ModInstrument object once C++17 support is dropped.

git-svn-id: https://source.openmpt.org/svn/openmpt/trunk/OpenMPT@22580 56274372-70c3-4bfc-bfc3-4c3a0b034d27

Author: sagamusix

soundlib/ModInstrument.cpp

@@ -152,18 +152,6 @@ void InstrumentEnvelope::Sanitize(uint8 maxValue)
 }
 
 
-ModInstrument::ModInstrument(SAMPLEINDEX sample)
-{
-	SetCutoff(0, false);
-	SetResonance(0, false);
-
-	pitchToTempoLock.Set(0);
-
-	AssignSample(sample);
-	ResetNoteMap();
-}
-
-
 // Translate instrument properties between two given formats.
 void ModInstrument::Convert(MODTYPE fromType, MODTYPE toType)
 {

soundlib/ModInstrument.h

@@ -35,8 +35,8 @@ struct EnvelopeNode
 	tick_t tick = 0;   // Envelope node position (x axis)
 	value_t value = 0; // Envelope node value (y axis)
 
-	EnvelopeNode() { }
-	EnvelopeNode(tick_t tick, value_t value) : tick(tick), value(value) { }
+	constexpr EnvelopeNode() = default;
+	constexpr EnvelopeNode(tick_t tick, value_t value) : tick{tick}, value{value} { }
 
 	bool operator== (const EnvelopeNode &other) const { return tick == other.tick && value == other.value; }
 };
@@ -128,16 +128,20 @@ struct ModInstrument
 	// WHEN adding new members here, ALSO update InstrumentExtensions.cpp
 	// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
-	explicit ModInstrument(SAMPLEINDEX sample = 0);
+	MPT_CONSTEXPR20_FUN explicit ModInstrument(SAMPLEINDEX sample = 0)
+	{
+		AssignSample(sample);
+		ResetNoteMap();
+	}
 
 	// Assign all notes to a given sample.
-	void AssignSample(SAMPLEINDEX sample)
+	MPT_CONSTEXPR20_FUN void AssignSample(SAMPLEINDEX sample)
 	{
 		Keyboard.fill(sample);
 	}
 
 	// Reset note mapping (i.e. every note is mapped to itself)
-	void ResetNoteMap()
+	MPT_CONSTEXPR20_FUN void ResetNoteMap()
 	{
 		std::iota(NoteMap.begin(), NoteMap.end(), static_cast<uint8>(NOTE_MIN));
 	}
@@ -149,23 +153,23 @@ struct ModInstrument
 	// Transpose entire note mapping by given number of semitones
 	void Transpose(int8 amount);
 
-	bool IsCutoffEnabled() const { return (nIFC & 0x80) != 0; }
-	bool IsResonanceEnabled() const { return (nIFR & 0x80) != 0; }
-	uint8 GetCutoff() const { return (nIFC & 0x7F); }
-	uint8 GetResonance() const { return (nIFR & 0x7F); }
-	void SetCutoff(uint8 cutoff, bool enable) { nIFC = std::min(cutoff, uint8(0x7F)) | (enable ? 0x80 : 0x00); }
-	void SetResonance(uint8 resonance, bool enable) { nIFR = std::min(resonance, uint8(0x7F)) | (enable ? 0x80 : 0x00); }
+	MPT_CONSTEXPRINLINE bool IsCutoffEnabled() const { return (nIFC & 0x80) != 0; }
+	MPT_CONSTEXPRINLINE bool IsResonanceEnabled() const { return (nIFR & 0x80) != 0; }
+	MPT_CONSTEXPRINLINE uint8 GetCutoff() const { return (nIFC & 0x7F); }
+	MPT_CONSTEXPRINLINE uint8 GetResonance() const { return (nIFR & 0x7F); }
+	MPT_CONSTEXPRINLINE void SetCutoff(uint8 cutoff, bool enable) { nIFC = std::min(cutoff, uint8(0x7F)) | (enable ? 0x80 : 0x00); }
+	MPT_CONSTEXPRINLINE void SetResonance(uint8 resonance, bool enable) { nIFR = std::min(resonance, uint8(0x7F)) | (enable ? 0x80 : 0x00); }
 
-	bool HasValidMIDIChannel() const { return (nMidiChannel >= 1 && nMidiChannel <= 17); }
+	MPT_CONSTEXPRINLINE bool HasValidMIDIChannel() const { return (nMidiChannel >= 1 && nMidiChannel <= 17); }
 	uint8 GetMIDIChannel(const ModChannel &channel, CHANNELINDEX chn) const;
 
-	void SetTuning(CTuning *pT)
+	MPT_CONSTEXPRINLINE void SetTuning(CTuning *pT)
 	{
 		pTuning = pT;
 	}
 
 	// Get a reference to a specific envelope of this instrument
-	const InstrumentEnvelope &GetEnvelope(EnvelopeType envType) const
+	MPT_CONSTEXPRINLINE const InstrumentEnvelope &GetEnvelope(EnvelopeType envType) const
 	{
 		switch(envType)
 		{

src/mpt/string/buffer.hpp

@@ -310,13 +310,13 @@ struct charbuf {
 	Tchar buf[len];
 
 public:
-	charbuf() {
+	MPT_CONSTEXPR20_FUN charbuf() {
 		std::fill(std::begin(buf), std::end(buf), char_constants<Tchar>::null);
 	}
-	charbuf(const charbuf &) = default;
-	charbuf(charbuf &&) = default;
-	charbuf & operator=(const charbuf &) = default;
-	charbuf & operator=(charbuf &&) = default;
+	constexpr charbuf(const charbuf &) = default;
+	constexpr charbuf(charbuf &&) = default;
+	constexpr charbuf & operator=(const charbuf &) = default;
+	constexpr charbuf & operator=(charbuf &&) = default;
 	const Tchar & operator[](std::size_t i) const {
 		return buf[i];
 	}