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++ // Copyright (C) 2021 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
++ // Qt-Security score:significant reason:default
++
++
++ #ifndef QQUICK3DPARTICLERANDOMIZER_H
++ #define QQUICK3DPARTICLERANDOMIZER_H
++
++ //
++ // W A R N I N G
++ // -------------
++ //
++ // This file is not part of the Qt API. It exists purely as an
++ // implementation detail. This header file may change from version to
++ // version without notice, or even be removed.
++ //
++ // We mean it.
++ //
++
++ #include <QRandomGenerator>
++ #include <QList>
++ #include <private/qglobal_p.h>
++
++ QT_BEGIN_NAMESPACE
++
++ /*
++
++ Simple helper to get pseudo-random numbers which remain the same per particle & user.
++ Particles don't need strong randomization and the ability to seed can be useful.
++
++ Based on brief testing on my laptop, getting 1.000.000 random numbers:
++
++ 1) Using QRandomGenerator::global()->generateDouble()
++ -> ~120ms
++
++ 2) Using QPRand::get(), with m_size 4096
++ -> ~8ms
++
++ 3) Using QPRand::get(i, j), with m_size 4096
++ -> ~10ms
++
++ 4) Using QPRand::get(i, j), with m_size 100000
++ -> ~10ms
++
++ So QPRand seems fast and increasing keys amount doesn't notably affect the performance,
++ just the memory usage. With more particles m_size should be relatively big to make sure
++ particles appear random enough.
++
++ Bounded usage tips:
++ - qrg->bounded(4.0) == QPRand::get() * 4.0
++ - qrg->bounded(4) == int(QPRand::get() * 4)
++
++ */
++
++ class QPRand
++ {
++ public:
++
++ // Add here new enums for diferent "users".
++ // This way e.g. particle can vary little on colors but more on sizes.
++ enum UserType {
++ Default = 0,
++ WanderXPS, // PaceStart
++ WanderYPS,
++ WanderZPS,
++ WanderXPV, // PaceVariation
++ WanderYPV,
++ WanderZPV,
++ WanderXAV, // AmountVariation
++ WanderYAV,
++ WanderZAV,
++ AttractorDurationV,
++ AttractorPosVX,
++ AttractorPosVY,
++ AttractorPosVZ,
++ Shape1, // Shape
++ Shape2,
++ Shape3,
++ Shape4,
++ SpriteAnimationI,
++ DeterministicSeparator, // Note: Enums before this must always be
++ // deterministic based on the particle index
++ LifeSpanV, // Emitter
++ ScaleV,
++ ScaleEV,
++ RotXV,
++ RotYV,
++ RotZV,
++ RotXVV,
++ RotYVV,
++ RotZVV,
++ ColorRV,
++ ColorGV,
++ ColorBV,
++ ColorAV,
++ TDirPosXV, // TargetDirection
++ TDirPosYV,
++ TDirPosZV,
++ TDirMagV,
++ VDirXV, // VectorDirection
++ VDirYV,
++ VDirZV,
++ SpriteAnimationV
++ };
++
++ void init(quint32 seed, int size = 65536) {
++ m_size = size;
++ m_generator.seed(seed);
++ m_randomList.clear();
++ m_randomList.reserve(m_size);
++ for (int i = 0; i < m_size; i++)
++ m_randomList << float(m_generator.generateDouble());
++ }
++
++ void setDeterministic(bool deterministic) {
++ m_deterministic = deterministic;
++ }
++
++ // Return float 0.0 - 1.0
++ // With the same input values, returns always the same output.
++ inline float get(int particleIndex, UserType user = Default) {
++ if (!m_deterministic && user > DeterministicSeparator)
++ return get();
++ int i = (particleIndex + user) % m_size;
++ return m_randomList.at(i);
++ }
++
++ // Return float 0.0 - 1.0 from random list
++ // Note: Not deterministic between runs
++ inline float get() {
++ m_index = (m_index < m_size - 1) ? m_index + 1 : 0;
++ return m_randomList.at(m_index);
++ }
++ QRandomGenerator generator() const
++ {
++ return m_generator;
++ }
++ private:
++ QRandomGenerator m_generator;
++ int m_size = 0;
++ int m_index = 0;
++ bool m_deterministic = false;
++ QList<float> m_randomList;
++
++ };
++
++ QT_END_NAMESPACE
++
++ #endif // QQUICK3DPARTICLERANDOMIZER_H