summaryrefslogtreecommitdiffstats
path: root/src/render/backend/triangleboundingvolume.cpp
blob: c30b419208f4d92ab578b1915fce31e0db95acd7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/****************************************************************************
**
** Copyright (C) 2015 Klaralvdalens Datakonsult AB (KDAB).
** Contact: https://www.qt.io/licensing/
**
** This file is part of the Qt3D module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** 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 Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or 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.GPL2 and 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-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "triangleboundingvolume_p.h"
#include <Qt3DRender/private/qray3d_p.h>

QT_BEGIN_NAMESPACE

namespace Qt3DRender {

namespace Render {

// Note: a, b, c in clockwise order
// RealTime Collision Detection page 192
bool intersectsSegmentTriangle(const RayCasting::QRay3D &ray,
                               const Vector3D &a,
                               const Vector3D &b,
                               const Vector3D &c,
                               Vector3D &uvw,
                               float &t)
{
    const Vector3D ab = b - a;
    const Vector3D ac = c - a;
    const Vector3D qp = (ray.origin() - ray.point(ray.distance()));

    const Vector3D n = Vector3D::crossProduct(ab, ac);
    const float d = Vector3D::dotProduct(qp, n);

    if (d <= 0.0f)
        return false;

    const Vector3D ap = ray.origin() - a;
    t = Vector3D::dotProduct(ap, n);

    if (t < 0.0f || t > d)
        return false;

    const Vector3D e = Vector3D::crossProduct(qp, ap);
    uvw.setY(Vector3D::dotProduct(ac, e));

    if (uvw.y() < 0.0f || uvw.y() > d)
        return false;

    uvw.setZ(-Vector3D::dotProduct(ab, e));

    if (uvw.z() < 0.0f || uvw.y() + uvw.z() > d)
        return false;

    const float ood = 1.0f / d;
    t *= ood;
    uvw.setY(uvw.y() * ood);
    uvw.setZ(uvw.z() * ood);
    uvw.setX(1.0f - uvw.y() - uvw.z());

    return true;
}

TriangleBoundingVolume::TriangleBoundingVolume()
    : QBoundingVolume()
{
}

/*
    The vertices a, b, c are assumed to be in counter clockwise order.
 */
TriangleBoundingVolume::TriangleBoundingVolume(Qt3DCore::QNodeId id, const Vector3D &a, const Vector3D &b, const Vector3D &c)
    : QBoundingVolume()
    , m_id(id)
    , m_a(a)
    , m_b(b)
    , m_c(c)
{}

Qt3DCore::QNodeId TriangleBoundingVolume::id() const
{
    return m_id;
}

bool TriangleBoundingVolume::intersects(const RayCasting::QRay3D &ray, Vector3D *q, Vector3D *uvw) const
{
    float t = 0.0f;
    Vector3D uvwr;
    const float intersected = intersectsSegmentTriangle(ray, m_c, m_b, m_a, uvwr, t);

    if (intersected) {
        if (q != nullptr)
            *q = ray.point(t);
        if (uvw != nullptr)
            *uvw = uvwr;
    }
    return intersected;
}

TriangleBoundingVolume::Type TriangleBoundingVolume::type() const
{
    return RayCasting::QBoundingVolume::Triangle;
}

Vector3D TriangleBoundingVolume::a() const
{
    return m_a;
}

Vector3D TriangleBoundingVolume::b() const
{
    return m_b;
}

Vector3D TriangleBoundingVolume::c() const
{
    return m_c;
}

void TriangleBoundingVolume::setA(const Vector3D &a)
{
    m_a = a;
}

void TriangleBoundingVolume::setB(const Vector3D &b)
{
    m_b = b;
}

void TriangleBoundingVolume::setC(const Vector3D &c)
{
    m_c = c;
}

TriangleBoundingVolume TriangleBoundingVolume::transformed(const Matrix4x4 &mat) const
{
    const Vector3D tA = mat * m_a;
    const Vector3D tB = mat * m_b;
    const Vector3D tC = mat * m_c;
    return TriangleBoundingVolume(id(), tA, tB, tC);
}

} // namespace Render

} // namespace Qt3DRender

QT_END_NAMESPACE