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++ // Copyright (C) 2024 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
++
++ #include "qcolorutil_p.h"
++
++ #include <QtGui/qcolor.h>
++ #include <QtGui/qvector3d.h>
++ #include <cmath>
++
++ QT_BEGIN_NAMESPACE
++
++ namespace {
++
++ // Poor man's RGB to YUV conversion with BT.709 coefficients
++ // from https://en.wikipedia.org/wiki/Y%E2%80%B2UV
++ QVector3D RGBToYUV(const QColor &c)
++ {
++ const float R = c.redF();
++ const float G = c.greenF();
++ const float B = c.blueF();
++ QVector3D yuv;
++ yuv[0] = 0.2126f * R + 0.7152f * G + 0.0722f * B;
++ yuv[1] = -0.09991f * R - 0.33609f * G + 0.436f * B;
++ yuv[2] = 0.615f * R - 0.55861f * G - 0.05639f * B;
++ return yuv;
++ }
++
++ } // namespace
++
++ bool fuzzyCompare(const QColor &lhs, const QColor &rhs, float tol)
++ {
++ const QVector3D lhsYuv = RGBToYUV(lhs);
++ const QVector3D rhsYuv = RGBToYUV(rhs);
++ const float relativeLumaDiff =
++ 0.5f * std::abs((lhsYuv[0] - rhsYuv[0]) / (lhsYuv[0] + rhsYuv[0]));
++ const float colorDiff = QVector3D::crossProduct(lhsYuv, rhsYuv).length();
++ return colorDiff < tol && relativeLumaDiff < tol;
++ }
++
++ QT_END_NAMESPACE