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 4ec09afb0997403f5eb8fa508c2fe391f795ef1e..83c9929f2ae3247ca82c2e825d9d4f3e08f3b6bc 100644 (file)
--- a/src/gamma_transfer_function.cc
+++ b/src/gamma_transfer_function.cc
@@ -56,13 +56,14 @@ GammaTransferFunction::GammaTransferFunction (double gamma)
 
 
 vector<double>
-GammaTransferFunction::make_lut (int bit_depth, bool inverse) const
+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));
        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;