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

# main.cpp Example File

deferred-renderer-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.
    **
    ** $QT_BEGIN_LICENSE:LGPL3$
    ** Commercial License Usage
    ** Licensees holding valid commercial Qt licenses may use this file in
    ** accordance with the commercial license agreement provided with the
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    ** 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.
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    ** $QT_END_LICENSE$
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    ****************************************************************************/

    #include <Qt3DCore/QEntity>
    #include <window.h>

    #include <Qt3DInput/QInputAspect>

    #include <Qt3DRenderer/QRenderAspect>
    #include <Qt3DRenderer/QFrameGraph>
    #include <Qt3DRenderer/QMaterial>
    #include <Qt3DRenderer/QSphereMesh>
    #include <Qt3DRenderer/QPlaneMesh>
    #include <Qt3DRenderer/QLayer>
    #include <Qt3DRenderer/QParameter>
    #include <Qt3DCore/QCamera>
    #include <Qt3DCore/QCameraLens>
    #include <Qt3DCore/QTransform>
    #include <Qt3DCore/QLookAtTransform>
    #include <Qt3DCore/QRotateTransform>
    #include <Qt3DCore/QTranslateTransform>
    #include <Qt3DRenderer/QPointLight>
    #include <Qt3DRenderer/QWindow>
    #include <Qt3DCore/qaspectengine.h>

    #include <QGuiApplication>

    #include "gbuffer.h"
    #include "deferredrenderer.h"
    #include "finaleffect.h"
    #include "sceneeffect.h"
    #include "pointlightblock.h"

    int main(int ac, char **av)
    {
        QGuiApplication app(ac, av);

        Qt3D::QWindow view;
        Qt3D::QInputAspect *input = new Qt3D::QInputAspect();
        view.registerAspect(input);

        // Root entity
        Qt3D::QEntity *rootEntity = new Qt3D::QEntity();
        rootEntity->setObjectName(QStringLiteral("rootEntity"));

        // Shared Components
        GBuffer *gBuffer = new GBuffer();
        FinalEffect *finalEffect = new FinalEffect();
        SceneEffect *sceneEffect = new SceneEffect();

        Qt3D::QSphereMesh *sphereMesh = new Qt3D::QSphereMesh();
        sphereMesh->setRings(50);
        sphereMesh->setSlices(100);

        Qt3D::QLayer *sceneLayer = new Qt3D::QLayer();
        sceneLayer->setNames(QStringList("scene"));

        Qt3D::QLayer *quadLayer = new Qt3D::QLayer();
        quadLayer->setNames(QStringList("screenQuad"));

        Qt3D::QPlaneMesh *planeMesh = new Qt3D::QPlaneMesh();
        planeMesh->setMeshResolution(QSize(2, 2));
        planeMesh->setWidth(2.0f);
        planeMesh->setHeight(2.0f);

        Qt3D::QPointLight *light1 = new Qt3D::QPointLight();
        light1->setColor(Qt::white);
        light1->setIntensity(1.5f);

        rootEntity->addComponent(light1);

        // Scene Camera
        Qt3D::QCamera *camera = view.defaultCamera();

        camera->setFieldOfView(45.0f);
        camera->setNearPlane(0.01f);
        camera->setFarPlane(1000.0f);
        camera->setProjectionType(Qt3D::QCameraLens::PerspectiveProjection);

        camera->setPosition(QVector3D(10.0f, 10.0f, -25.0f));
        camera->setUpVector(QVector3D(0.0f, 1.0f, 0.0f));
        camera->setViewCenter(QVector3D(0.0f, 0.0f, 10.0f));

        input->setCamera(camera);

        // FrameGraph
        Qt3D::QFrameGraph *frameGraph = new Qt3D::QFrameGraph();
        DeferredRenderer *deferredRenderer = new DeferredRenderer();
        deferredRenderer->setClearColor(Qt::black);
        deferredRenderer->setRect(QRectF(0.0f, 0.0f, 1.0f, 1.0f));
        deferredRenderer->setFinalPassCriteria(finalEffect->passCriteria());
        deferredRenderer->setGeometryPassCriteria(sceneEffect->passCriteria());
        deferredRenderer->setGBuffer(gBuffer);
        deferredRenderer->setSceneCamera(camera);
        deferredRenderer->setGBufferLayers(sceneLayer->names());
        deferredRenderer->setScreenQuadLayers(quadLayer->names());

        frameGraph->setActiveFrameGraph(deferredRenderer);
        view.setFrameGraph(frameGraph);

        // Scene Content
        Qt3D::QEntity *sphereOne = new Qt3D::QEntity(rootEntity);
        Qt3D::QMaterial *sphereOneMaterial = new Qt3D::QMaterial();

        sphereOneMaterial->setEffect(sceneEffect);
        sphereOneMaterial->addParameter(new Qt3D::QParameter(QStringLiteral("meshColor"), QColor(Qt::blue)));

        Qt3D::QTranslateTransform *sphereOneTranslate = new Qt3D::QTranslateTransform();
        sphereOneTranslate->setDx(-10.0f);
        sphereOneTranslate->setDy(0.0f);
        sphereOneTranslate->setDz(25.0f);

        Qt3D::QPointLight *light2 = new Qt3D::QPointLight();
        light2->setColor(Qt::white);
        light2->setIntensity(1.5f);

        sphereOne->addComponent(new Qt3D::QTransform(sphereOneTranslate));
        sphereOne->addComponent(sphereOneMaterial);
        sphereOne->addComponent(sphereMesh);
        sphereOne->addComponent(sceneLayer);
        sphereOne->addComponent(light2);

        Qt3D::QEntity *sphereTwo = new Qt3D::QEntity(rootEntity);
        Qt3D::QMaterial *sphereTwoMaterial = new Qt3D::QMaterial();
        sphereTwoMaterial->setEffect(sceneEffect);
        sphereTwoMaterial->addParameter(new Qt3D::QParameter(QStringLiteral("meshColor"), QColor(Qt::yellow)));

        Qt3D::QPointLight *light3 = new Qt3D::QPointLight();
        light3->setColor(Qt::blue);
        light3->setIntensity(0.5f);

        sphereTwo->addComponent(sphereMesh);
        sphereTwo->addComponent(sceneLayer);
        sphereTwo->addComponent(sphereTwoMaterial);
        sphereTwo->addComponent(light3);

        // Screen Quad
        Qt3D::QEntity *screenQuad = new Qt3D::QEntity(rootEntity);
        Qt3D::QMaterial *screenQuadMaterial = new Qt3D::QMaterial();
        screenQuadMaterial->addParameter(new Qt3D::QParameter(QStringLiteral("position"), gBuffer->positionTexture()));
        screenQuadMaterial->addParameter(new Qt3D::QParameter(QStringLiteral("normal"), gBuffer->normalTexture()));
        screenQuadMaterial->addParameter(new Qt3D::QParameter(QStringLiteral("color"), gBuffer->colorTexture()));
        screenQuadMaterial->addParameter(new Qt3D::QParameter(QStringLiteral("winSize"), QSize(1024, 1024)));
        PointLightBlock *lightsData = new PointLightBlock(screenQuadMaterial);
        lightsData->addLight(light1);
        lightsData->addLight(light2);
        lightsData->addLight(light3);

        finalEffect->gl3Technique()->addParameter(new Qt3D::QParameter(QStringLiteral("PointLightBlock"), QVariant::fromValue(lightsData)));
        finalEffect->gl2Technique()->addParameter(new Qt3D::QParameter(QStringLiteral("pointLights"), QVariant::fromValue(lightsData)));
        screenQuadMaterial->setEffect(finalEffect);

        Qt3D::QRotateTransform *screenPlaneRotation = new Qt3D::QRotateTransform();
        screenPlaneRotation->setAngleDeg(90);
        screenPlaneRotation->setAxis(QVector3D(1.0f, 0.0f, 0.0f));

        screenQuad->addComponent(quadLayer);
        screenQuad->addComponent(new Qt3D::QTransform(screenPlaneRotation));
        screenQuad->addComponent(screenQuadMaterial);
        screenQuad->addComponent(planeMesh);

        // Set root object of the scene
        view.setRootEntity(rootEntity);
        // Show window
        view.show();

        return app.exec();
    }