Initial community commit

Src/external_dependencies/openmpt-trunk/soundlib/plugins/dmo/ParamEq.cpp

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+/*
+ * ParamEq.cpp
+ * -----------
+ * Purpose: Implementation of the DMO Parametric Equalizer DSP (for non-Windows platforms)
+ * Notes  : (currently none)
+ * Authors: OpenMPT Devs
+ * The OpenMPT source code is released under the BSD license. Read LICENSE for more details.
+ */
+
+
+#include "stdafx.h"
+
+#ifndef NO_PLUGINS
+#include "../../Sndfile.h"
+#include "ParamEq.h"
+#include "mpt/base/numbers.hpp"
+#endif // !NO_PLUGINS
+
+OPENMPT_NAMESPACE_BEGIN
+
+#ifndef NO_PLUGINS
+
+namespace DMO
+{
+
+IMixPlugin* ParamEq::Create(VSTPluginLib &factory, CSoundFile &sndFile, SNDMIXPLUGIN *mixStruct)
+{
+	return new (std::nothrow) ParamEq(factory, sndFile, mixStruct);
+}
+
+
+ParamEq::ParamEq(VSTPluginLib &factory, CSoundFile &sndFile, SNDMIXPLUGIN *mixStruct)
+	: IMixPlugin(factory, sndFile, mixStruct)
+	, m_maxFreqParam(1.0f)
+{
+	m_param[kEqCenter] = (8000.0f - 80.0f) / 15920.0f;
+	m_param[kEqBandwidth] = 0.314286f;
+	m_param[kEqGain] = 0.5f;
+
+	m_mixBuffer.Initialize(2, 2);
+	InsertIntoFactoryList();
+}
+
+
+void ParamEq::Process(float *pOutL, float *pOutR, uint32 numFrames)
+{
+	if(!m_mixBuffer.Ok())
+		return;
+
+	const float *in[2] = { m_mixBuffer.GetInputBuffer(0), m_mixBuffer.GetInputBuffer(1) };
+	float *out[2] = { m_mixBuffer.GetOutputBuffer(0), m_mixBuffer.GetOutputBuffer(1) };
+
+	if(m_param[kEqGain] == 0.5f)
+	{
+		memcpy(out[0], in[0], numFrames * sizeof(float));
+		memcpy(out[1], in[1], numFrames * sizeof(float));
+	} else
+	{
+		for(uint32 i = numFrames; i != 0; i--)
+		{
+			for(uint8 channel = 0; channel < 2; channel++)
+			{
+				float x = *(in[channel])++;
+				float y = b0DIVa0 * x + b1DIVa0 * x1[channel] + b2DIVa0 * x2[channel] - a1DIVa0 * y1[channel] - a2DIVa0 * y2[channel];
+
+				x2[channel] = x1[channel];
+				x1[channel] = x;
+				y2[channel] = y1[channel];
+				y1[channel] = y;
+
+				*(out[channel])++ = y;
+			}
+		}
+	}
+
+	ProcessMixOps(pOutL, pOutR, m_mixBuffer.GetOutputBuffer(0), m_mixBuffer.GetOutputBuffer(1), numFrames);
+}
+
+
+PlugParamValue ParamEq::GetParameter(PlugParamIndex index)
+{
+	if(index < kEqNumParameters)
+	{
+		return m_param[index];
+	}
+	return 0;
+}
+
+
+void ParamEq::SetParameter(PlugParamIndex index, PlugParamValue value)
+{
+	if(index < kEqNumParameters)
+	{
+		value = mpt::safe_clamp(value, 0.0f, 1.0f);
+		m_param[index] = value;
+		RecalculateEqParams();
+	}
+}
+
+
+void ParamEq::Resume()
+{
+	m_isResumed = true;
+	// Limit center frequency to a third of the sampling rate.
+	m_maxFreqParam = Clamp((m_SndFile.GetSampleRate() / 3.0f - 80.0f) / 15920.0f, 0.0f, 1.0f);
+	RecalculateEqParams();
+	PositionChanged();
+}
+
+
+void ParamEq::PositionChanged()
+{
+	// Reset filter state
+	x1[0] = x2[0] = 0;
+	x1[1] = x2[1] = 0;
+	y1[0] = y2[0] = 0;
+	y1[1] = y2[1] = 0;
+}
+
+
+#ifdef MODPLUG_TRACKER
+
+CString ParamEq::GetParamName(PlugParamIndex param)
+{
+	switch(param)
+	{
+	case kEqCenter: return _T("Center");
+	case kEqBandwidth: return _T("Bandwidth");
+	case kEqGain: return _T("Gain");
+	}
+	return CString();
+}
+
+
+CString ParamEq::GetParamLabel(PlugParamIndex param)
+{
+	switch(param)
+	{
+	case kEqCenter: return _T("Hz");
+	case kEqBandwidth: return _T("Semitones");
+	case kEqGain: return _T("dB");
+	}
+	return CString();
+}
+
+
+CString ParamEq::GetParamDisplay(PlugParamIndex param)
+{
+	float value = 0.0f;
+	switch(param)
+	{
+	case kEqCenter:
+		value = FreqInHertz();
+		break;
+	case kEqBandwidth:
+		value = BandwidthInSemitones();
+		break;
+	case kEqGain:
+		value = GainInDecibel();
+		break;
+	}
+	CString s;
+	s.Format(_T("%.2f"), value);
+	return s;
+}
+
+#endif // MODPLUG_TRACKER
+
+
+void ParamEq::RecalculateEqParams()
+{
+	LimitMax(m_param[kEqCenter], m_maxFreqParam);
+	const float freq = FreqInHertz() / m_SndFile.GetSampleRate();
+	const float a = std::pow(10.0f, GainInDecibel() / 40.0f);
+	const float w0 = 2.0f * mpt::numbers::pi_v<float> * freq;
+	const float sinW0 = std::sin(w0);
+	const float cosW0 = std::cos(w0);
+	const float alpha = sinW0 * std::sinh((BandwidthInSemitones() * (mpt::numbers::ln2_v<float> / 24.0f)) * w0 / sinW0);
+
+	const float b0 = 1.0f + alpha * a;
+	const float b1 = -2.0f * cosW0;
+	const float b2 = 1.0f - alpha * a;
+	const float a0 = 1.0f + alpha / a;
+	const float a1 = -2.0f * cosW0;
+	const float a2 = 1.0f - alpha / a;
+
+	b0DIVa0 = b0 / a0;
+	b1DIVa0 = b1 / a0;
+	b2DIVa0 = b2 / a0;
+	a1DIVa0 = a1 / a0;
+	a2DIVa0 = a2 / a0;
+}
+
+} // namespace DMO
+
+#else
+MPT_MSVC_WORKAROUND_LNK4221(ParamEq)
+
+#endif // !NO_PLUGINS
+
+OPENMPT_NAMESPACE_END