1 files changed, 171 insertions, 0 deletions
diff --git a/src/render/backend/triangleboundingvolume.cpp b/src/render/backend/triangleboundingvolume.cpp
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+++ b/src/render/backend/triangleboundingvolume.cpp
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+/****************************************************************************
+**
+** Copyright (C) 2015 Klaralvdalens Datakonsult AB (KDAB).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** 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 http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://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.LGPLv3 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.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 later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "triangleboundingvolume_p.h"
+#include <Qt3DCore/qray3d.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace Qt3DRender {
+
+namespace Render {
+
+// Note: a, b, c in clockwise order
+// RealTime Collision Detection page 192
+bool intersectsSegmentTriangle(const Qt3DCore::QRay3D &ray,
+                               const QVector3D &a,
+                               const QVector3D &b,
+                               const QVector3D &c,
+                               QVector3D &uvw,
+                               float &t)
+{
+    const QVector3D ab = b - a;
+    const QVector3D ac = c - a;
+    const QVector3D qp = (ray.origin() - ray.point(ray.distance()));
+
+    const QVector3D n = QVector3D::crossProduct(ab, ac);
+    const float d = QVector3D::dotProduct(qp, n);
+
+    if (d <= 0.0f)
+        return false;
+
+    const QVector3D ap = ray.origin() - a;
+    t = QVector3D::dotProduct(ap, n);
+
+    if (t < 0.0f || t > d)
+        return false;
+
+    const QVector3D e = QVector3D::crossProduct(qp, ap);
+    uvw.setY(QVector3D::dotProduct(ac, e));
+
+    if (uvw.y() < 0.0f || uvw.y() > d)
+        return false;
+
+    uvw.setZ(-QVector3D::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()
+    : Qt3DCore::QBoundingVolume()
+{
+}
+
+/*!
+    The vertices a, b, c are assumed to be in counter clockwise order.
+ */
+TriangleBoundingVolume::TriangleBoundingVolume(const Qt3DCore::QNodeId &id, const QVector3D &a, const QVector3D &b, const QVector3D &c)
+    : Qt3DCore::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 Qt3DCore::QRay3D &ray, QVector3D *q) const
+{
+    float t = 0.0f;
+    QVector3D uvw;
+    const float intersected = intersectsSegmentTriangle(ray, m_c, m_b, m_a, uvw, t);
+
+    if (intersected && q != Q_NULLPTR)
+        *q = ray.origin() + t * ray.direction();
+
+    return intersected;
+}
+
+Qt3DCore::QBoundingVolume::Type TriangleBoundingVolume::type() const
+{
+    return Qt3DCore::QBoundingVolume::Triangle;
+}
+
+QVector3D TriangleBoundingVolume::a() const
+{
+    return m_a;
+}
+
+QVector3D TriangleBoundingVolume::b() const
+{
+    return m_b;
+}
+
+QVector3D TriangleBoundingVolume::c() const
+{
+    return m_c;
+}
+
+void TriangleBoundingVolume::setA(const QVector3D &a)
+{
+    m_a = a;
+}
+
+void TriangleBoundingVolume::setB(const QVector3D &b)
+{
+    m_b = b;
+}
+
+void TriangleBoundingVolume::setC(const QVector3D &c)
+{
+    m_c = c;
+}
+
+TriangleBoundingVolume TriangleBoundingVolume::transformed(const QMatrix4x4 &mat) const
+{
+    const QVector3D tA = mat * m_a;
+    const QVector3D tB = mat * m_b;
+    const QVector3D tC = mat * m_c;
+    return TriangleBoundingVolume(id(), tA, tB, tC);
+}
+
+} // namespace Render
+
+} // namespace Qt3DRender
+
+QT_END_NAMESPACE