ValueFilter.h

/*
 * Copyright 2014-2015 Matthew McGowan.
 *
 * This file is part of Nice Firmware.
 *
 * BrewPi 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 3 of the License, or
 * (at your option) any later version.
 *
 * This library 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 BrewPi.  If not, see <http://www.gnu.org/licenses/>.
 */


#pragma once

#include "Values.h"
#include "FilterCascaded.h"


// Todo wonder if the different values should be made available as a container.
// Container is best if the values need to be logged, but may not be needed if the ValueSource* is itself
// a logged value.
class FilterValue : public Value, ValueSource
{
	ValueSource* source;
	CascadedFilter filter;

public:

	/**
	 * Value 0 - 2 bytes, current output
	 * Value 1 - 4 bytes, current output (high precision)
	 */
	bool getValue(void* value, uint8_t id) {
		uint8_t result = true;
		if (id==0)
			*((fixed7_9*)value) = filter.readOutput();
		else if (id==1)
			*((fixed23_9*)value) = filter.readOutputDoublePrecision();
		return result;
	}

	void readTo(DataOut& out) {
		fixed23_9 value = filter.readOutputDoublePrecision();
		writeBytes(&value, 4, out);

	}

	void writeMaskedFrom(DataIn& in, DataIn& mask) {

	}

	// read/write externally provides both the filter value and filter settings.
	// masking is needed to avoid altering the filter value when changing settings.
	static Object* Create(ObjectDef	inition& def)
	{
		// 1-byte co-efficients
		// id_chain of ValueSource to fetch input value from
		// the filter could be instantiated directly by the controller as part of the container
		// provided by the controller so that no need for a separate create command in eeprom.
		// And the controller knows which object to use as input. This would save a lot of eeprom space.
		return new_object(FilterValue());
	}
};