/*
	This file is part of EqualizerAPO, a system-wide equalizer.
	Copyright (C) 2012  Jonas Thedering

	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; if not, write to the Free Software Foundation, Inc.,
	51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#pragma once

#include <string>
#include <vector>

#define IS_DENORMAL(f) (((*(unsigned int *)&(f))&0x7f800000) == 0)

struct BiQuad
{
	BiQuad() {}
	BiQuad(float dbGain, float freq, float srate, float bandwidthOrQ, bool isQ);

	__forceinline
	void removeDenormals()
	{
		if(IS_DENORMAL(x1))
			x1 = 0.0f;
		if(IS_DENORMAL(x2))
			x2 = 0.0f;
		if(IS_DENORMAL(y1))
			y1 = 0.0f;
		if(IS_DENORMAL(y2))
			y2 = 0.0f;
	}

	__forceinline
	float process(float sample)
	{
		float result = a0 * sample + a[0] * x1 + a[1] * x2 +
			a[2] * y1 + a[3] * y2;

		x2 = x1;
		x1 = sample;

		y2 = y1;
		y1 = result;

		//Input for next stage
		return result;
	}

	__declspec(align(16)) float a[4];
	float a0;

	float x1, x2;
	float y1, y2;
};

struct ChannelData
{
	ChannelData();

	float preamp;
	unsigned filterCount;
	BiQuad filters[100];

	// used while loading instead of overwriting immediately
	float loadPreamp;
	unsigned loadFilterCount;
};

class ParametricEQ
{
public:
	ParametricEQ();
	~ParametricEQ();

	void setDeviceInfo(const std::wstring& deviceName, const std::wstring& connectionName, const std::wstring& deviceGuid);
	void initialize(float sampleRate, unsigned channelCount, unsigned channelMask);
	void loadConfig();
	void process(float *output, float *input, unsigned frameCount);

private:
	void loadConfig(const std::wstring& path, std::vector<bool> selectedChannels);
	float getFreq(const std::wstring& freqString);
	unsigned getChannelNumber(unsigned position);
	static unsigned long __stdcall notificationThread(void* parameter);

	std::wstring deviceName;
	std::wstring connectionName;
	std::wstring deviceGuid;
	std::wstring configPath;
	float sampleRate;
	unsigned channelCount;
	unsigned channelMask;
	ChannelData* channelData;
	bool lastInputWasSilent;
	void* threadHandle;
	void* shutdownEvent;
};