- Qt 5.5
- Qt3D Module
- Qt3D: Basic Shapes C++ Example
- main.cpp Example File
- Qt 5.5.1 Reference Documentation

# main.cpp Example File

basicshapes-cpp/main.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2014 Klaralvdalens Datakonsult AB (KDAB).
    ** Contact: http://www.qt-project.org/legal
    **
    ** This file is part of the Qt3D module of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:LGPL3$
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    ** 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
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    ** 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
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    #include "scenemodifier.h"

    #include <QGuiApplication>

    #include <window.h>
    #include <Qt3DCore/qcamera.h>
    #include <Qt3DCore/qentity.h>
    #include <Qt3DCore/qcameralens.h>

    #include <QtWidgets/QApplication>
    #include <QtWidgets/QWidget>
    #include <QtWidgets/QHBoxLayout>
    #include <QtWidgets/QCheckBox>
    #include <QtWidgets/QCommandLinkButton>
    #include <QtGui/QScreen>

    #include <Qt3DInput/QInputAspect>

    #include <Qt3DRenderer/qtorusmesh.h>
    #include <Qt3DRenderer/qmesh.h>
    #include <Qt3DRenderer/qtechnique.h>
    #include <Qt3DRenderer/qmaterial.h>
    #include <Qt3DRenderer/qeffect.h>
    #include <Qt3DRenderer/qtexture.h>
    #include <Qt3DRenderer/qrenderpass.h>
    #include <Qt3DRenderer/qsceneloader.h>

    #include <Qt3DCore/qscaletransform.h>
    #include <Qt3DCore/qrotatetransform.h>
    #include <Qt3DCore/qlookattransform.h>
    #include <Qt3DCore/qtransform.h>
    #include <Qt3DCore/qaspectengine.h>

    #include <Qt3DRenderer/qrenderaspect.h>
    #include <Qt3DRenderer/qframegraph.h>
    #include <Qt3DRenderer/qforwardrenderer.h>

    int main(int argc, char **argv)
    {
        QApplication app(argc, argv);
        Window *view = new Window();
        QWidget *container = QWidget::createWindowContainer(view);
        QSize screenSize = view->screen()->size();
        container->setMinimumSize(QSize(200, 100));
        container->setMaximumSize(screenSize);

        QWidget *widget = new QWidget;
        QHBoxLayout *hLayout = new QHBoxLayout(widget);
        QVBoxLayout *vLayout = new QVBoxLayout();
        vLayout->setAlignment(Qt::AlignTop);
        hLayout->addWidget(container, 1);
        hLayout->addLayout(vLayout);

        widget->setWindowTitle(QStringLiteral("Basic shapes"));

        Qt3D::QAspectEngine engine;
        engine.registerAspect(new Qt3D::QRenderAspect());
        Qt3D::QInputAspect *input = new Qt3D::QInputAspect;
        engine.registerAspect(input);
        engine.initialize();
        QVariantMap data;
        data.insert(QStringLiteral("surface"), QVariant::fromValue(static_cast<QSurface *>(view)));
        data.insert(QStringLiteral("eventSource"), QVariant::fromValue(view));
        engine.setData(data);

        // Root entity
        Qt3D::QEntity *rootEntity = new Qt3D::QEntity();

        // Camera
        Qt3D::QCamera *cameraEntity = new Qt3D::QCamera(rootEntity);
        cameraEntity->setObjectName(QStringLiteral("cameraEntity"));

        cameraEntity->lens()->setPerspectiveProjection(45.0f, 16.0f/9.0f, 0.1f, 1000.0f);
        cameraEntity->setPosition(QVector3D(0, 0, -20.0f));
        cameraEntity->setUpVector(QVector3D(0, 1, 0));
        cameraEntity->setViewCenter(QVector3D(0, 0, 0));
        input->setCamera(cameraEntity);

        // FrameGraph
        Qt3D::QFrameGraph *frameGraph = new Qt3D::QFrameGraph();
        Qt3D::QForwardRenderer *forwardRenderer = new Qt3D::QForwardRenderer();

        forwardRenderer->setCamera(cameraEntity);
        forwardRenderer->setClearColor(QColor(QRgb(0x4d4d4f)));
        frameGraph->setActiveFrameGraph(forwardRenderer);

        // Setting the FrameGraph
        rootEntity->addComponent(frameGraph);

        // Scenemodifier
        SceneModifier *modifier = new SceneModifier(rootEntity);

        // Set root object of the scene
        engine.setRootEntity(rootEntity);

        // Create control widgets
        QCommandLinkButton *info = new QCommandLinkButton();
        info->setText(QStringLiteral("Qt3D ready-made meshes"));
        info->setDescription(QStringLiteral("Qt3D provides several ready-made meshes, like torus, cylinder, cube and sphere."));
        info->setIconSize(QSize(0,0));

        QCheckBox *torusCB = new QCheckBox(widget);
        torusCB->setChecked(true);
        torusCB->setText(QStringLiteral("Torus"));

        QCheckBox *cylinderCB = new QCheckBox(widget);
        cylinderCB->setChecked(true);
        cylinderCB->setText(QStringLiteral("Cylinder"));

        QCheckBox *cuboidCB = new QCheckBox(widget);
        cuboidCB->setChecked(true);
        cuboidCB->setText(QStringLiteral("Cuboid"));

        QCheckBox *sphereCB = new QCheckBox(widget);
        sphereCB->setChecked(true);
        sphereCB->setText(QStringLiteral("Sphere"));

        vLayout->addWidget(info);
        vLayout->addWidget(torusCB);
        vLayout->addWidget(cylinderCB);
        vLayout->addWidget(cuboidCB);
        vLayout->addWidget(sphereCB);

        QObject::connect(torusCB, &QCheckBox::stateChanged,
                         modifier, &SceneModifier::enableTorus);
        QObject::connect(cylinderCB, &QCheckBox::stateChanged,
                         modifier, &SceneModifier::enableCylinder);
        QObject::connect(cuboidCB, &QCheckBox::stateChanged,
                         modifier, &SceneModifier::enableCuboid);
        QObject::connect(sphereCB, &QCheckBox::stateChanged,
                         modifier, &SceneModifier::enableSphere);

        torusCB->setChecked(true);
        cylinderCB->setChecked(true);
        cuboidCB->setChecked(true);
        sphereCB->setChecked(true);

        // Show window
        widget->show();
        widget->resize(1200, 800);

        // Update the aspect ratio
        QSize widgetSize =  container->size();
        float aspectRatio = float(widgetSize.width()) / float(widgetSize.height());
        cameraEntity->lens()->setPerspectiveProjection(45.0f, aspectRatio, 0.1f, 1000.0f);

        return app.exec();
    }