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/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the QtCanvas3D 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.
**
** $QT_END_LICENSE$
**
****************************************************************************/
/*!
\example canvas3d/jsonmodels
\since QtCanvas3D 1.0
\title JSON Models Example
\ingroup qtcanvas3d-examples
\brief Load and display several JSON models
The JSON Models Example demonstrates loading and displaying more than
one JSON model and more than one texture. It also implements simple
mouse input handling to allow rotating the scene and zooming into it.
The example optionally incorporates some Qt Quick Enterprise Controls,
which you can switch on by commenting out the \c{#define NO_ENTERPRISE}
line in \l{canvas3d/jsonmodels/main.cpp}{main.cpp}. The controls are used to toggle
some optional animations and draw options, as well as displaying camera
rotations and distance.
\image jsonmodels-example.png
\section1 JSON Model Loader
First we include a JSON model parser, which handles parsing the JSON
models into our internal models:
\snippet canvas3d/jsonmodels/qml/jsonmodels/jsonmodels.js 0
The \c{ThreeJSLoader.js} includes a reimplementation of the JSON parser
in \c{three.js}, but we will not go into its implementation details.
\section1 Loading the Models
First we need to initialize all array buffers for the models:
\snippet canvas3d/jsonmodels/qml/jsonmodels/jsonmodels.js 1
\dots
Then we request the models to be loaded:
\snippet canvas3d/jsonmodels/qml/jsonmodels/jsonmodels.js 2
\dots
Then, when the load requests return, we handle the models:
\snippet canvas3d/jsonmodels/qml/jsonmodels/jsonmodels.js 3
\dots
Each buffer is bound and filled with the data parsed from the json models:
\snippet canvas3d/jsonmodels/qml/jsonmodels/jsonmodels.js 4
\section1 Loading the Textures
First we create the TextureImage objects for each of the images we are
going to load and register handlers for the \c imageLoaded and
\c imageLoadingFailed signals. In the \c imageLoaded signal
handlers we create the OpenGL textures:
\snippet canvas3d/jsonmodels/qml/jsonmodels/jsonmodels.js 5
\dots
\section1 Input Handling
First we add a MouseArea to fill the Canvas3D:
\snippet canvas3d/jsonmodels/qml/jsonmodels/jsonmodels.qml 0
\dots
Before adding some functionality on it, we need to add properties to the
canvas with initial values set:
\snippet canvas3d/jsonmodels/qml/jsonmodels/jsonmodels.qml 1
After that, we add rotation on mouse movement when the left mouse button
is pressed:
\snippet canvas3d/jsonmodels/qml/jsonmodels/jsonmodels.qml 2
We need to keep the previous x and y values to avoid rotation jumping
when the mouse button is released and pressed again. We store them in
these properties:
\snippet canvas3d/jsonmodels/qml/jsonmodels/jsonmodels.qml 3
Then we add zooming by mouse wheel:
\snippet canvas3d/jsonmodels/qml/jsonmodels/jsonmodels.qml 4
These properties are then used in the JavaScript side when calculating
eye/camera movement:
\snippet canvas3d/jsonmodels/qml/jsonmodels/jsonmodels.js 7
Converting the rotation values into movement is done as follows:
\snippet canvas3d/jsonmodels/qml/jsonmodels/jsonmodels.js 8
*/
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