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* libscopeprotocols                                                                                                    *
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* Copyright (c) 2012-2022 Andrew D. Zonenberg and contributors                                                         *
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#include "../scopehal/scopehal.h"
#include "VectorFrequencyFilter.h"

using namespace std;

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Construction / destruction

VectorFrequencyFilter::VectorFrequencyFilter(const string& color)
	: Filter(color, CAT_RF)
{
	AddStream(Unit(Unit::UNIT_HZ), "data", Stream::STREAM_TYPE_ANALOG);
	CreateInput("I");
	CreateInput("Q");
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Factory methods

bool VectorFrequencyFilter::ValidateChannel(size_t i, StreamDescriptor stream)
{
	if(stream.m_channel == NULL)
		return false;

	if( (i < 2) && (stream.GetType() == Stream::STREAM_TYPE_ANALOG) )
		return true;

	return false;
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Accessors

string VectorFrequencyFilter::GetProtocolName()
{
	return "Vector Frequency";
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Actual decoder logic

void VectorFrequencyFilter::Refresh()
{
	//Make sure we've got valid inputs
	if(!VerifyAllInputsOKAndUniformAnalog())
	{
		SetData(NULL, 0);
		return;
	}

	auto din_i = dynamic_cast<UniformAnalogWaveform*>(GetInputWaveform(0));
	auto din_q = dynamic_cast<UniformAnalogWaveform*>(GetInputWaveform(1));
	size_t len = min(din_i->size(), din_q->size());
	din_i->PrepareForCpuAccess();
	din_q->PrepareForCpuAccess();

	auto dout = SetupEmptyUniformAnalogOutputWaveform(din_i, 0);
	dout->PrepareForCpuAccess();
	dout->Resize(len);

	//Calculate scaling factor from rad/sample to Hz
	float sample_hz = FS_PER_SECOND / din_i->m_timescale;
	float scale = sample_hz / (2 * M_PI);
	for(size_t i=0; i<len-1; i++)
	{
		//TODO: this can probably be made more efficient...
		float theta1 = atan2(din_q->m_samples[i], din_i->m_samples[i]);
		float theta2 = atan2(din_q->m_samples[i+1], din_i->m_samples[i+1]);
		float dphase = theta2 - theta1;
		if(dphase < -M_PI)
			dphase += 2*M_PI;
		if(dphase > M_PI)
			dphase -= 2*M_PI;

		dout->m_samples[i] = dphase * scale;
	}

	dout->MarkModifiedFromCpu();
}
