303             double targetNits = 0.0;  in lookupTonemapGain()  local
309                             targetNits = xyz.y;  in lookupTonemapGain()
315                             targetNits = std::clamp(xyz.y, 0.0f, 1000.0f);  in lookupTonemapGain()
316                             targetNits *= std::pow(targetNits / 1000.f, -0.2 / 1.2);  in lookupTonemapGain()
322                             targetNits = xyz.y;  in lookupTonemapGain()
325                                 targetNits *= std::pow(targetNits, 0.2);  in lookupTonemapGain()
346                                 if (targetNits < x0) {  in lookupTonemapGain()
349                                     targetNits *= slope;  in lookupTonemapGain()
350                                 } else if (targetNits < x1) {  in lookupTonemapGain()
353                                     targetNits = y0 + (targetNits - x0) * slope;  in lookupTonemapGain()
354                                 } else if (targetNits < x2) {  in lookupTonemapGain()
356                                     double t = (targetNits - x1) / h12;  in lookupTonemapGain()
357                                     targetNits = (y1 * (1.0 + 2.0 * t) + h12 * m1 * t) * (1.0 - t) *  in lookupTonemapGain()
363                                     double t = (targetNits - x2) / h23;  in lookupTonemapGain()
364                                     targetNits = (y2 * (1.0 + 2.0 * t) + h23 * m2 * t) * (1.0 - t) *  in lookupTonemapGain()
397                             targetNits = xyz.y;  in lookupTonemapGain()
399                             if (targetNits <= x0) {  in lookupTonemapGain()
402                                 targetNits *= slope;  in lookupTonemapGain()
403                             } else if (targetNits <= x1) {  in lookupTonemapGain()
405                                 double t = (targetNits - x0) / (x1 - x0);  in lookupTonemapGain()
406                                 targetNits = (1.0 - t) * (1.0 - t) * y0 + 2.0 * (1.0 - t) * t * c1 +  in lookupTonemapGain()
408                             } else if (targetNits <= x2) {  in lookupTonemapGain()
410                                 double t = (targetNits - x1) / (x2 - x1);  in lookupTonemapGain()
411                                 targetNits = (1.0 - t) * (1.0 - t) * y1 + 2.0 * (1.0 - t) * t * c2 +  in lookupTonemapGain()
415                                 double t = (targetNits - x2) / (x3 - x2);  in lookupTonemapGain()
416                                 targetNits = (1.0 - t) * (1.0 - t) * y2 + 2.0 * (1.0 - t) * t * c3 +  in lookupTonemapGain()
421                                 targetNits *= std::pow(targetNits / 1000.0, -0.2 / 1.2);  in lookupTonemapGain()
427                             targetNits = xyz.y;  in lookupTonemapGain()
431             gains.push_back(targetNits / xyz.y);  in lookupTonemapGain()
669             double targetNits = 0.0;  in lookupTonemapGain()  local
674                             targetNits = maxRGB;  in lookupTonemapGain()
680                             targetNits = std::clamp(maxRGB, 0.0, 1000.0);  in lookupTonemapGain()
681                             targetNits *= pow(targetNits / 1000.0, (1 - hlgGamma) / (hlgGamma));  in lookupTonemapGain()
684                             targetNits = maxRGB;  in lookupTonemapGain()
685                             if (targetNits < x1) {  in lookupTonemapGain()
689                             if (targetNits > maxInLumi) {  in lookupTonemapGain()
690                                 targetNits = maxOutLumi;  in lookupTonemapGain()
694                             const double greyNits = OETF_ST2084(targetNits);  in lookupTonemapGain()
697                                 targetNits = (greyNits - greyNorm2) * slope2 + y2;  in lookupTonemapGain()
699                                 targetNits = (greyNits - greyNorm3) * slope3 + y3;  in lookupTonemapGain()
701                                 targetNits = maxOutLumi;  in lookupTonemapGain()
709                             targetNits = maxRGB * pow(maxRGB / 1000.0, hlgGamma - 1);  in lookupTonemapGain()
712                             targetNits = maxRGB;  in lookupTonemapGain()
715                             targetNits = maxRGB * pow(maxRGB / 1000.0, hlgGamma - 1) *  in lookupTonemapGain()
721                     targetNits = maxRGB;  in lookupTonemapGain()
725             gains.push_back(targetNits / maxRGB);  in lookupTonemapGain()