1// Copyright (C) 2019 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
3
4#include "qquick3dfrustumcamera_p.h"
5
6#include <QtQuick3DRuntimeRender/private/qssgrendercamera_p.h>
7
8#include <QtMath>
9#include <QtQuick3DUtils/private/qssgutils_p.h>
10
11#include "qquick3dutils_p.h"
12
13#include "qquick3dnode_p_p.h"
14
15QT_BEGIN_NAMESPACE
16
17/*!
18 \qmltype FrustumCamera
19 \inherits PerspectiveCamera
20 \inqmlmodule QtQuick3D
21 \brief Defines a PerspectiveCamera with a custom frustum.
22
23 A \l Camera defines how the content of the 3D scene is projected onto a 2D surface,
24 such as a View3D. A scene needs at least one \l Camera in order to visualize its
25 contents.
26
27 It is possible to position and rotate the \l Camera like any other spatial \l{QtQuick3D::Node}{Node} in
28 the scene. The \l{QtQuick3D::Node}{Node}'s location and orientation determines where the \l Camera is in
29 the scene, and what direction it is facing. The default orientation of the \l Camera
30 has its forward vector pointing along the negative Z axis and its up vector along
31 the positive Y axis.
32
33 The FrustumCamera type provides a PerspectiveCamera where the frustum bounds can be
34 customized. This can be useful for creating asymmetrical frustums.
35
36 The following example creates a FrustumCamera at [0, 0, 100] in the scene.
37 The \l {PerspectiveCamera::clipNear}{near plane} is placed 100 units in front of the camera at the origin.
38 The intersection of the frustum and the near plane is then given by the rectangle that has a bottom left corner at [-5, -5],
39 and a top right corner at [5, 5], and continues until it intersect the
40 \l {PerspectiveCamera::clipFar}{far plane}, which is located 1000 units from the camera at [0, 0, -900].
41
42 \note The \l{PerspectiveCamera::fieldOfViewOrientation}{vertical field of view} angle is
43 a product of the distance between the camera, the \l {PerspectiveCamera::clipNear}{near plane}
44 and the length between the \c top and \c bottom of the near plane.
45
46 \note If the top and bottom, or left right, values are asymmetric,
47 the apex of the frustum will be shifted, effectively offsetting the camera from its location.
48
49 \code
50 FrustumCamera {
51 position: Qt.vector3d(0, 0, 100)
52 clipNear: 100
53 clipFar: 1000
54 top: 5
55 bottom: -5
56 left: -5
57 right: 5
58 }
59 \endcode
60
61 \sa PerspectiveCamera, OrthographicCamera, CustomCamera
62*/
63
64/*!
65 * \internal
66 */
67QQuick3DFrustumCamera::QQuick3DFrustumCamera(QQuick3DNode *parent)
68 : QQuick3DPerspectiveCamera(*(new QQuick3DNodePrivate(QQuick3DNodePrivate::Type::CustomFrustumCamera)), parent)
69{}
70
71/*!
72 \qmlproperty real FrustumCamera::top
73
74 The \c top value specifies the top of the \l{PerspectiveCamera::clipNear}{near clip plane},
75 relative to the camera's position in local coordinates.
76*/
77float QQuick3DFrustumCamera::top() const
78{
79 return m_top;
80}
81
82/*!
83 \qmlproperty real FrustumCamera::bottom
84
85 The \c bottom value specifies the bottom of the \l{PerspectiveCamera::clipNear}{near clip plane},
86 relative to the camera's position in local coordinates.
87*/
88float QQuick3DFrustumCamera::bottom() const
89{
90 return m_bottom;
91}
92
93/*!
94 \qmlproperty real FrustumCamera::right
95
96 The \c right value specifies the right of the \l{PerspectiveCamera::clipNear}{near clip plane},
97 relative to the camera's position in local coordinates.
98*/
99float QQuick3DFrustumCamera::right() const
100{
101 return m_right;
102}
103
104/*!
105 \qmlproperty real FrustumCamera::left
106
107 The \c left value specifies the left of the \l{PerspectiveCamera::clipNear}{near clip plane},
108 relative to the camera's position in local coordinates.
109*/
110float QQuick3DFrustumCamera::left() const
111{
112 return m_left;
113}
114
115void QQuick3DFrustumCamera::setTop(float top)
116{
117 if (qFuzzyCompare(p1: m_top, p2: top))
118 return;
119
120 m_top = top;
121 emit topChanged();
122 update();
123}
124
125void QQuick3DFrustumCamera::setBottom(float bottom)
126{
127 if (qFuzzyCompare(p1: m_bottom, p2: bottom))
128 return;
129
130 m_bottom = bottom;
131 emit bottomChanged();
132 update();
133}
134
135void QQuick3DFrustumCamera::setRight(float right)
136{
137 if (qFuzzyCompare(p1: m_right, p2: right))
138 return;
139
140 m_right = right;
141 emit rightChanged();
142 update();
143}
144
145void QQuick3DFrustumCamera::setLeft(float left)
146{
147 if (qFuzzyCompare(p1: m_left, p2: left))
148 return;
149
150 m_left = left;
151 emit leftChanged();
152 update();
153}
154
155QSSGRenderGraphObject *QQuick3DFrustumCamera::updateSpatialNode(QSSGRenderGraphObject *node)
156{
157 // NOTE: The frustum camera extends the perspective camera!
158 QSSGRenderCamera *camera = static_cast<QSSGRenderCamera *>(QQuick3DPerspectiveCamera::updateSpatialNode(node));
159 if (camera) {
160 const bool changed = ((int(qUpdateIfNeeded(orig&: camera->top, updated: m_top))
161 | int(qUpdateIfNeeded(orig&: camera->bottom, updated: m_bottom))
162 | int(qUpdateIfNeeded(orig&: camera->right, updated: m_right))
163 | int(qUpdateIfNeeded(orig&: camera->left, updated: m_left))) != 0);
164 if (changed)
165 camera->markDirty(dirtyFlag: QSSGRenderCamera::DirtyFlag::CameraDirty);
166 }
167
168 return camera;
169}
170
171QT_END_NAMESPACE
172

source code of qtquick3d/src/quick3d/qquick3dfrustumcamera.cpp