Version 1.0

Added: Configuration Editor, which allows to edit configurations in a graphical user interface. Contains GUIs for most commands supported by E-APO, but as lines can also be edited directly, all commands can be used.
Added: Command "GraphicEQ", which can act as a regular, fixed-band graphic equalizer (via the GUI) but also supports variable bands so that any desired frequency response can be specified. Internally, it is implemented via convolution with a generated IR.
Added: Command "Convolution", which allows to convolve the signal with a user-provided impulse response to achieve e.g. equalization or reverberation effects.
Improved: Configurator performs checks for registry values that are needed for the operation of E-APO, which may be changed by driver installations, fixing the values if necessary.
Improved: Configurator shows which is the default device as a hint to the user.

Editor/widgets/FrequencyPlotScene.cpp

@@ -0,0 +1,129 @@
+/*
+	This file is part of EqualizerAPO, a system-wide equalizer.
+	Copyright (C) 2015  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.
+*/
+
+#include "FrequencyPlotView.h"
+#include "FrequencyPlotScene.h"
+
+using namespace std;
+
+static double maxX = 1000;
+static double maxY = 500;
+static double minHz = 1;
+static double maxHz = 30000;
+static double minDb = -100;
+static double maxDb = 100;
+
+vector<double> FrequencyPlotScene::bands15 = {25, 40, 63, 100, 160, 250, 400, 630, 1000, 1600, 2500, 4000, 6300, 10000, 16000};
+vector<double> FrequencyPlotScene::bands31 = {20, 25, 31.5, 40, 50, 63, 80, 100, 125, 160, 200, 250, 315, 400, 500, 630, 800,
+											  1000, 1250, 1600, 2000, 2500, 3150, 4000, 5000, 6300, 8000, 10000, 12500, 16000, 20000
+											 };
+vector<double> FrequencyPlotScene::bandsVar;
+
+FrequencyPlotScene::FrequencyPlotScene(QObject *parent) :
+	QGraphicsScene(parent)
+{
+	updateSceneRect();
+}
+
+void FrequencyPlotScene::addItem(FrequencyPlotItem* item)
+{
+	QGraphicsScene::addItem(item);
+}
+
+double FrequencyPlotScene::xToHz(double x)
+{
+	return pow(maxHz / minHz, x / zoom / maxX) * minHz;
+}
+
+double FrequencyPlotScene::hzToX(double hz)
+{
+	if(hz < minHz || hz > maxHz)
+		return -1;
+
+	return log(hz / minHz) / log(maxHz / minHz) * maxX * zoom;
+}
+
+double FrequencyPlotScene::yToDb(double y)
+{
+	return (minDb + (1 - y / zoom / maxY) * (maxDb - minDb));
+}
+
+double FrequencyPlotScene::dbToY(double db)
+{
+	if(db < minDb || db > maxDb)
+		return -1;
+
+	return (1 - (db - minDb) / (maxDb - minDb)) * maxY * zoom;
+}
+
+double FrequencyPlotScene::getZoom() const
+{
+	return zoom;
+}
+
+void FrequencyPlotScene::setZoom(double value)
+{
+	zoom = value;
+	updateSceneRect();
+
+	for(QGraphicsItem* item : items())
+	{
+		FrequencyPlotItem* plotItem = (FrequencyPlotItem*)item;
+		plotItem->updatePos();
+	}
+}
+
+void FrequencyPlotScene::updateSceneRect()
+{
+	setSceneRect(0, 0, maxX * zoom, maxY * zoom);
+}
+
+int FrequencyPlotScene::getBandCount() const
+{
+	return bandCount;
+}
+
+void FrequencyPlotScene::setBandCount(int value)
+{
+	if(value != bandCount)
+	{
+		bandCount = value;
+		update();
+		FrequencyPlotView* view = qobject_cast<FrequencyPlotView*>(views()[0]);
+		view->updateHRuler();
+	}
+}
+
+const vector<double>& FrequencyPlotScene::getBands()
+{
+	return getBands(bandCount);
+}
+
+const std::vector<double>&FrequencyPlotScene::getBands(int count)
+{
+	switch(count)
+	{
+	case 15:
+		return bands15;
+	case 31:
+		return bands31;
+	default:
+		return bandsVar;
+	}
+}