/*
 * ParamEq.h
 * ---------
 * 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 "../PlugInterface.h"

OPENMPT_NAMESPACE_BEGIN

namespace DMO
{

class ParamEq final : public IMixPlugin
{
protected:
	enum Parameters
	{
		kEqCenter = 0,
		kEqBandwidth,
		kEqGain,
		kEqNumParameters
	};

	std::array<float, kEqNumParameters> m_param;

	// Equalizer coefficients
	float b0DIVa0, b1DIVa0, b2DIVa0, a1DIVa0, a2DIVa0;
	// Equalizer memory
	float x1[2], x2[2];
	float y1[2], y2[2];
	float m_maxFreqParam;

public:
	static IMixPlugin* Create(VSTPluginLib &factory, CSoundFile &sndFile, SNDMIXPLUGIN &mixStruct);
	ParamEq(VSTPluginLib &factory, CSoundFile &sndFile, SNDMIXPLUGIN &mixStruct);

	int32 GetUID() const override { return 0x120CED89; }
	int32 GetVersion() const override { return 0; }
	void Idle() override { }
	uint32 GetLatency() const override { return 0; }

	void Process(float *pOutL, float *pOutR, uint32 numFrames) override;

	float RenderSilence(uint32) override { return 0.0f; }

	int32 GetNumPrograms() const override { return 0; }
	int32 GetCurrentProgram() override { return 0; }
	void SetCurrentProgram(int32) override { }

	PlugParamIndex GetNumParameters() const override { return kEqNumParameters; }
	PlugParamValue GetParameter(PlugParamIndex index) override;
	void SetParameter(PlugParamIndex index, PlugParamValue value, PlayState * = nullptr, CHANNELINDEX = CHANNELINDEX_INVALID) override;

	void Resume() override;
	void Suspend() override { m_isResumed = false; }
	void PositionChanged() override;

	bool IsInstrument() const override { return false; }
	bool CanRecieveMidiEvents() override { return false; }
	bool ShouldProcessSilence() override { return true; }

#ifdef MODPLUG_TRACKER
	CString GetDefaultEffectName() override { return _T("ParamEq"); }

	CString GetParamName(PlugParamIndex param) override;
	CString GetParamLabel(PlugParamIndex) override;
	CString GetParamDisplay(PlugParamIndex param) override;

	CString GetCurrentProgramName() override { return CString(); }
	void SetCurrentProgramName(const CString &) override { }
	CString GetProgramName(int32) override { return CString(); }

	bool HasEditor() const override { return false; }
#endif

	int GetNumInputChannels() const override { return 2; }
	int GetNumOutputChannels() const override { return 2; }

protected:
	float BandwidthInSemitones() const { return 1.0f + m_param[kEqBandwidth] * 35.0f; }
	float FreqInHertz() const { return 80.0f + m_param[kEqCenter] * 15920.0f; }
	float GainInDecibel() const { return (m_param[kEqGain] - 0.5f) * 30.0f; }
	void RecalculateEqParams();
};

} // namespace DMO

OPENMPT_NAMESPACE_END
