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39
40#include "entityaccumulator_p.h"
41#include "entityvisitor_p.h"
42
43QT_USE_NAMESPACE
44using namespace Qt3DRender::Render;
45
46namespace {
47
48class Accumulator : public EntityVisitor
49{
50public:
51 Accumulator(std::function<bool(Entity *)> predicate, NodeManagers *manager)
52 : EntityVisitor(manager)
53 , m_predicate(predicate)
54 {
55 }
56
57 EntityVisitor::Operation visit(Entity *entity) override {
58 if (m_predicate(entity))
59 m_entities << entity;
60 return Continue;
61 }
62
63 QVector<Entity *> m_entities;
64
65private:
66 std::function<bool(Entity *)> m_predicate;
67};
68
69}
70
71EntityAccumulator::EntityAccumulator(NodeManagers *manager)
72 : m_manager(manager)
73 , m_predicate([](Entity*) { return true; })
74{
75
76}
77
78EntityAccumulator::EntityAccumulator(std::function<bool (Entity *)> predicate, NodeManagers *manager)
79 : m_manager(manager)
80 , m_predicate(predicate)
81{
82
83}
84
85/*!
86 * \internal
87 *
88 * Call this to traverse the scene graph and return all entities for
89 * which the predicate returns true.
90 *
91 * Can be useful to get all the entities that contain a specific type
92 * of component.
93 */
94QVector<Entity *> EntityAccumulator::apply(Entity *root) const
95{
96 Accumulator a(m_predicate, m_manager);
97 a.apply(root);
98 return a.m_entities;
99}
100

source code of qt3d/src/render/backend/entityaccumulator.cpp