Rename lut -> double_lut.

[libdcp.git] / src / gamma_transfer_function.cc

diff --git a/src/gamma_transfer_function.cc b/src/gamma_transfer_function.cc
index bf773fb3b66fca6ec024c994528378e9b7db4ad5..83c9929f2ae3247ca82c2e825d9d4f3e08f3b6bc 100644 (file)
--- a/src/gamma_transfer_function.cc
+++ b/src/gamma_transfer_function.cc
@@ -1,61 +1,82 @@
 /*
-    Copyright (C) 2012-2014 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2012-2021 Carl Hetherington <cth@carlh.net>
 
-    This program is free software; you can redistribute it and/or modify
+    This file is part of libdcp.
+
+    libdcp 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,
+    libdcp 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.
+    along with libdcp.  If not, see <http://www.gnu.org/licenses/>.
+
+    In addition, as a special exception, the copyright holders give
+    permission to link the code of portions of this program with the
+    OpenSSL library under certain conditions as described in each
+    individual source file, and distribute linked combinations
+    including the two.
 
+    You must obey the GNU General Public License in all respects
+    for all of the code used other than OpenSSL.  If you modify
+    file(s) with this exception, you may extend this exception to your
+    version of the file(s), but you are not obligated to do so.  If you
+    do not wish to do so, delete this exception statement from your
+    version.  If you delete this exception statement from all source
+    files in the program, then also delete it here.
 */
 
+
+/** @file  src/gamma_transfer_function.cc
+ *  @brief GammaTransferFunction class
+ */
+
+
 #include "gamma_transfer_function.h"
 #include <cmath>
 
+
+using std::dynamic_pointer_cast;
 using std::pow;
-using boost::shared_ptr;
-using boost::dynamic_pointer_cast;
+using std::shared_ptr;
+using std::vector;
 using namespace dcp;
 
-GammaTransferFunction::GammaTransferFunction (bool inverse, double gamma)
-       : TransferFunction (inverse)
-       , _gamma (gamma)
+
+GammaTransferFunction::GammaTransferFunction (double gamma)
+       : _gamma (gamma)
 {
 
 }
 
-double *
-GammaTransferFunction::make_lut (int bit_depth) const
+
+vector<double>
+GammaTransferFunction::make_double_lut(double from, double to, int bit_depth, bool inverse) const
 {
        int const bit_length = int(std::pow(2.0f, bit_depth));
-       double* lut = new double[bit_length];
-       double const gamma = _inverse ? (1 / _gamma) : _gamma;
+       auto lut = vector<double>(bit_length);
+       double const gamma = inverse ? (1 / _gamma) : _gamma;
        for (int i = 0; i < bit_length; ++i) {
-               lut[i] = pow(double(i) / (bit_length - 1), gamma);
+               double const x = double(i) / (bit_length - 1);
+               lut[i] = pow((x * (to - from)) + from, gamma);
        }
 
        return lut;
 }
 
+
 bool
 GammaTransferFunction::about_equal (shared_ptr<const TransferFunction> other, double epsilon) const
 {
-       if (!TransferFunction::about_equal (other, epsilon)) {
-               return false;
-       }
-       
-       shared_ptr<const GammaTransferFunction> o = dynamic_pointer_cast<const GammaTransferFunction> (other);
+       auto o = dynamic_pointer_cast<const GammaTransferFunction>(other);
        if (!o) {
                return false;
        }
 
-       return fabs (_gamma - o->_gamma) < epsilon;
+       return fabs(_gamma - o->_gamma) < epsilon;
 }