| 1 | // Copyright (C) 2019 The Qt Company Ltd. |
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| 2 | // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only |
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| 3 | |
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| 4 | #ifndef QQUICK3DUTILS_P_H |
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| 5 | #define QQUICK3DUTILS_P_H |
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| 6 | |
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| 7 | // |
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| 8 | // W A R N I N G |
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| 9 | // ------------- |
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| 10 | // |
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| 11 | // This file is not part of the Qt API. It exists purely as an |
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| 12 | // implementation detail. This header file may change from version to |
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| 13 | // version without notice, or even be removed. |
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| 14 | // |
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| 15 | // We mean it. |
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| 16 | // |
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| 17 | |
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| 18 | #include <type_traits> |
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| 19 | |
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| 20 | #include <QtCore/QtGlobal> |
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| 21 | #include <private/qglobal_p.h> |
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| 22 | |
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| 23 | QT_BEGIN_NAMESPACE |
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| 24 | |
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| 25 | template <typename T, typename = void> |
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| 26 | struct hasFuzzyCompare : std::false_type {}; |
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| 27 | |
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| 28 | template <typename T> |
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| 29 | struct hasFuzzyCompare<T, std::void_t<decltype(qFuzzyCompare(std::declval<T &>(), std::declval<T &>()))>> : std::true_type {}; |
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| 30 | |
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| 31 | // Assigns 'updated' to 'orig' and returns true if they are different |
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| 32 | template <typename T, std::enable_if_t<!hasFuzzyCompare<T>::value, bool> = true> |
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| 33 | bool qUpdateIfNeeded(T &orig, T updated) |
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| 34 | { |
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| 35 | if (orig == updated) |
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| 36 | return false; |
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| 37 | orig = updated; |
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| 38 | return true; |
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| 39 | } |
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| 40 | |
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| 41 | // Assigns 'updated' to 'orig' and returns true if they are different, compared with qFuzzyCompare |
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| 42 | template <typename T, std::enable_if_t<hasFuzzyCompare<T>::value, bool> = true> |
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| 43 | bool qUpdateIfNeeded(T &orig, T updated) |
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| 44 | { |
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| 45 | if (qFuzzyCompare(orig, updated)) |
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| 46 | return false; |
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| 47 | orig = updated; |
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| 48 | return true; |
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| 49 | } |
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| 50 | |
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| 51 | QT_END_NAMESPACE |
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| 52 | |
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| 53 | #endif // QQUICK3DUTILS_P_H |
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| 54 | |
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