1/****************************************************************************
2**
3** Copyright (C) 2016 Paul Lemire
4** Contact: https://www.qt.io/licensing/
5**
6** This file is part of the Qt3D module of the Qt Toolkit.
7**
8** $QT_BEGIN_LICENSE:LGPL$
9** Commercial License Usage
10** Licensees holding valid commercial Qt licenses may use this file in
11** accordance with the commercial license agreement provided with the
12** Software or, alternatively, in accordance with the terms contained in
13** a written agreement between you and The Qt Company. For licensing terms
14** and conditions see https://www.qt.io/terms-conditions. For further
15** information use the contact form at https://www.qt.io/contact-us.
16**
17** GNU Lesser General Public License Usage
18** Alternatively, this file may be used under the terms of the GNU Lesser
19** General Public License version 3 as published by the Free Software
20** Foundation and appearing in the file LICENSE.LGPL3 included in the
21** packaging of this file. Please review the following information to
22** ensure the GNU Lesser General Public License version 3 requirements
23** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
24**
25** GNU General Public License Usage
26** Alternatively, this file may be used under the terms of the GNU
27** General Public License version 2.0 or (at your option) the GNU General
28** Public license version 3 or any later version approved by the KDE Free
29** Qt Foundation. The licenses are as published by the Free Software
30** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
31** included in the packaging of this file. Please review the following
32** information to ensure the GNU General Public License requirements will
33** be met: https://www.gnu.org/licenses/gpl-2.0.html and
34** https://www.gnu.org/licenses/gpl-3.0.html.
35**
36** $QT_END_LICENSE$
37**
38****************************************************************************/
39
40#include "frustumcullingjob_p.h"
41#include <Qt3DRender/private/job_common_p.h>
42#include <Qt3DRender/private/managers_p.h>
43#include <Qt3DRender/private/entity_p.h>
44#include <Qt3DRender/private/sphere_p.h>
45#include <Qt3DRender/private/managers_p.h>
46#include <Qt3DRender/private/nodemanagers_p.h>
47
48QT_BEGIN_NAMESPACE
49
50namespace Qt3DRender {
51
52namespace Render {
53
54namespace {
55int instanceCounter = 0;
56} // anonymous
57
58FrustumCullingJob::FrustumCullingJob()
59 : Qt3DCore::QAspectJob()
60 , m_root(nullptr)
61 , m_manager(nullptr)
62 , m_active(false)
63{
64 SET_JOB_RUN_STAT_TYPE(this, JobTypes::FrustumCulling, instanceCounter++)
65}
66
67FrustumCullingJob::~FrustumCullingJob()
68{
69 --instanceCounter;
70}
71
72void FrustumCullingJob::run()
73{
74 // Early return if not activated
75 if (!m_active)
76 return;
77
78 m_visibleEntities.clear();
79
80 const Plane planes[6] = {
81 Plane(m_viewProjection.row(index: 3) + m_viewProjection.row(index: 0)), // Left
82 Plane(m_viewProjection.row(index: 3) - m_viewProjection.row(index: 0)), // Right
83 Plane(m_viewProjection.row(index: 3) + m_viewProjection.row(index: 1)), // Top
84 Plane(m_viewProjection.row(index: 3) - m_viewProjection.row(index: 1)), // Bottom
85 Plane(m_viewProjection.row(index: 3) + m_viewProjection.row(index: 2)), // Front
86 Plane(m_viewProjection.row(index: 3) - m_viewProjection.row(index: 2)), // Back
87 };
88
89 cullScene(e: m_root, planes);
90
91 // sort needed for set_intersection in RenderViewBuilder
92 std::sort(first: m_visibleEntities.begin(), last: m_visibleEntities.end());
93}
94
95void FrustumCullingJob::cullScene(Entity *e, const Plane *planes)
96{
97 e->traverse(operation: [planes, this](Entity *e) {
98 const Sphere *s = e->worldBoundingVolumeWithChildren();
99
100 // Unrolled loop
101 if (Vector3D::dotProduct(a: s->center(), b: planes[0].normal) + planes[0].d < -s->radius())
102 return;
103 if (Vector3D::dotProduct(a: s->center(), b: planes[1].normal) + planes[1].d < -s->radius())
104 return;
105 if (Vector3D::dotProduct(a: s->center(), b: planes[2].normal) + planes[2].d < -s->radius())
106 return;
107 if (Vector3D::dotProduct(a: s->center(), b: planes[3].normal) + planes[3].d < -s->radius())
108 return;
109 if (Vector3D::dotProduct(a: s->center(), b: planes[4].normal) + planes[4].d < -s->radius())
110 return;
111 if (Vector3D::dotProduct(a: s->center(), b: planes[5].normal) + planes[5].d < -s->radius())
112 return;
113
114 m_visibleEntities.push_back(t: e);
115 });
116}
117
118} // Render
119
120} // Qt3DRender
121
122QT_END_NAMESPACE
123

source code of qt3d/src/render/jobs/frustumcullingjob.cpp