livetrax/libs/surfaces/mackie/meter.cc

/*
	Copyright (C) 2006,2007 John Anderson
	Copyright (C) 2012 Paul Davis

	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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <cmath>

#include "pbd/compose.h"
#include "ardour/debug.h"

#include "meter.h"
#include "surface.h"
#include "surface_port.h"
#include "control_group.h"

using namespace PBD;
using namespace ArdourSurface;
using namespace Mackie;

Control*
Meter::factory (Surface& surface, int id, const char* name, Group& group)
{
	Meter* m = new Meter (id, name, group);
	surface.meters[id] = m;
	surface.controls.push_back (m);
	group.add (*m);
	return m;
}

void
Meter::notify_metering_state_changed(Surface& surface, bool transport_is_rolling, bool metering_active)
{
	MidiByteArray msg;

	// sysex header
	msg << surface.sysex_hdr();

	// code for Channel Meter Enable Message
	msg << 0x20;

	// Channel identification
	msg << id();

	// Enable (0x07) / Disable (0x00) level meter on LCD, peak hold display on horizontal meter and signal LED
	msg << ((transport_is_rolling && metering_active) ? 0x07 : 0x00);

	// sysex trailer
	msg << MIDI::eox;

	surface.write (msg);
}

void
Meter::send_update (Surface& surface, float dB)
{
	float def = 0.0f; /* Meter deflection %age */

	// DEBUG_TRACE (DEBUG::MackieControl, string_compose ("Meter ID %1 dB %2\n", id(), dB));

	if (dB < -70.0f) {
		def = 0.0f;
	} else if (dB < -60.0f) {
		def = (dB + 70.0f) * 0.25f;
	} else if (dB < -50.0f) {
		def = (dB + 60.0f) * 0.5f + 2.5f;
	} else if (dB < -40.0f) {
		def = (dB + 50.0f) * 0.75f + 7.5f;
	} else if (dB < -30.0f) {
		def = (dB + 40.0f) * 1.5f + 15.0f;
	} else if (dB < -20.0f) {
		def = (dB + 30.0f) * 2.0f + 30.0f;
	} else if (dB < 6.0f) {
		def = (dB + 20.0f) * 2.5f + 50.0f;
	} else {
		def = 115.0f;
	}

	/* 115 is the deflection %age that would be
	   when dB=6.0. this is an arbitrary
	   endpoint for our scaling.
	*/

	MidiByteArray msg;

	if (def > 100.0f) {
		if (!overload_on) {
			overload_on = true;
			surface.write (MidiByteArray (2, 0xd0, (id() << 4) | 0xe));

		}
	} else {
		if (overload_on) {
			overload_on = false;
			surface.write (MidiByteArray (2, 0xd0, (id() << 4) | 0xf));
		}
	}

	/* we can use up to 13 segments */

	int segment = lrintf ((def/115.0) * 13.0);

	surface.write (MidiByteArray (2, 0xd0, (id()<<4) | segment));
}

MidiByteArray
Meter::zero ()
{
	return MidiByteArray (2, 0xD0, (id()<<4 | 0));
}