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Diffstat (limited to 'res/effectlib/luminance.glsllib')
-rw-r--r-- | res/effectlib/luminance.glsllib | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/res/effectlib/luminance.glsllib b/res/effectlib/luminance.glsllib new file mode 100644 index 0000000..067dc18 --- /dev/null +++ b/res/effectlib/luminance.glsllib @@ -0,0 +1,62 @@ +/**************************************************************************** +** +** Copyright (C) 2014 NVIDIA Corporation. +** Copyright (C) 2017 The Qt Company Ltd. +** Contact: https://www.qt.io/licensing/ +** +** This file is part of Qt 3D Studio. +** +** $QT_BEGIN_LICENSE:GPL$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3 or (at your option) any later version +** approved by the KDE Free Qt Foundation. The licenses are as published by +** the Free Software Foundation and appearing in the file LICENSE.GPL3 +** included in the packaging of this file. Please review the following +** information to ensure the GNU General Public License requirements will +** be met: https://www.gnu.org/licenses/gpl-3.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#ifndef LUMINANCE_GLSLLIB +#define LUMINANCE_GLSLLIB + +// Luma coefficients according to ITU-R Recommendation BT.709 (http://en.wikipedia.org/wiki/Rec._709) +const vec3 yCoeff_709 = vec3( 0.2126, 0.7152, 0.0722 ); + +float luminance( in vec3 v ) +{ + return dot( v, yCoeff_709 ); +} + +vec3 RGBToYPbPr( in vec3 v ) +{ + vec3 ypp; + ypp.x = luminance( v ); + ypp.y = 0.5 * (v.b - ypp.x) / (1.0 - yCoeff_709.b); + ypp.z = 0.5 * (v.r - ypp.x) / (1.0 - yCoeff_709.r); + + return ypp; +} + +vec3 YPbPrToRGB( in vec3 v ) +{ + vec3 outRGB; + outRGB.x = dot(vec3(1.0, 0.0, 1.575), v); + outRGB.y = dot(vec3(1.0, -0.187, -0.468), v); + outRGB.z = dot(vec3(1.0, 1.856, 0.0), v); + + return outRGB; +} + +#endif
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