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++ // Copyright (C) 2023 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
++
++ // Blinn-Phong
++ vec4 qt_specularBlinnPhong(in vec3 N, in vec3 L, in vec3 V, in vec3 lightSpecular, in float shininess)
++ {
++ vec4 rgba = vec4(0.0, 0.0, 0.0, 1.0);
++ vec3 H = normalize(V + L);
++ float cosAlpha = max(0.0, dot(H, N));
++ float shine = pow(cosAlpha, shininess);
++ rgba.rgb = shine * lightSpecular;
++ return rgba;
++ }