added simple local contrast tool

Borrowed from G'MIC

rtgui/localcontrast.h

@@ -0,0 +1,47 @@
+/** -*- C++ -*-
+ *  
+ *  This file is part of RawTherapee.
+ *
+ *  Copyright (c) 2017 Alberto Griggio <alberto.griggio@gmail.com>
+ *
+ *  RawTherapee 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.
+ *
+ *  RawTherapee 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 RawTherapee.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include <gtkmm.h>
+#include "adjuster.h"
+#include "toolpanel.h"
+
+class LocalContrast: public ToolParamBlock, public AdjusterListener, public FoldableToolPanel
+{
+protected:
+    Adjuster *radius;
+    Adjuster *amount;
+    Adjuster *darkness;
+    Adjuster *lightness;
+
+public:
+
+    LocalContrast();
+
+    void read(const rtengine::procparams::ProcParams *pp, const ParamsEdited *pedited=nullptr);
+    void write(rtengine::procparams::ProcParams *pp, ParamsEdited *pedited=nullptr);
+    void setDefaults(const rtengine::procparams::ProcParams *defParams, const ParamsEdited *pedited=nullptr);
+    void setBatchMode(bool batchMode);
+
+    void adjusterChanged(Adjuster *a, double newval);
+    void enabledChanged();
+    // void setAdjusterBehavior(bool alphaAdd, bool betaAdd);
+};
+