--- /dev/null
+/*
+ Copyright (C) 2015 Carl Hetherington <cth@carlh.net>
+
+ 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 "gamma_transfer_function.h"
+#include "modified_gamma_transfer_function.h"
+#include <boost/test/unit_test.hpp>
+
+using boost::shared_ptr;
+
+/** Check GammaTransferFunction::about_equal */
+BOOST_AUTO_TEST_CASE (gamma_transfer_function_test)
+{
+ shared_ptr<dcp::GammaTransferFunction> a (new dcp::GammaTransferFunction (1.2));
+ shared_ptr<dcp::GammaTransferFunction> b (new dcp::GammaTransferFunction (1.2));
+ BOOST_CHECK (a->about_equal (b, 1e-6));
+
+ a.reset (new dcp::GammaTransferFunction (1.2));
+ a.reset (new dcp::GammaTransferFunction (1.3));
+ BOOST_CHECK (a->about_equal (b, 0.2));
+ BOOST_CHECK (!a->about_equal (b, 0.05));
+
+ shared_ptr<dcp::ModifiedGammaTransferFunction> c (new dcp::ModifiedGammaTransferFunction (2.4, 0.05, 1, 2));
+ BOOST_CHECK (!a->about_equal (c, 1));
+}