Qt 5.6 | Qt 3D | Qt 3D: Big Scene C++ Example | main.cpp Example File

Qt 5.6.3 Reference Documentation

# main.cpp Example File

bigscene-cpp/main.cpp

      /****************************************************************************
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      ** Copyright (C) 2014 Klaralvdalens Datakonsult AB (KDAB).
      ** Contact: http://www.qt-project.org/legal
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      #include "entity.h"

      #include <QGuiApplication>
      #include <window.h>

      #include <QPropertyAnimation>
      #include <QUrl>
      #include <QTimer>
      #include <Qt3DCore/QEntity>
      #include <Qt3DCore/QCamera>
      #include <Qt3DCore/QTransform>
      #include <Qt3DCore/qaspectengine.h>
      #include <Qt3DInput/QInputAspect>
      #include <Qt3DRender/QParameter>
      #include <Qt3DRender/QFrameGraph>
      #include <Qt3DRender/QCylinderMesh>
      #include <Qt3DRender/QRenderAspect>
      #include <Qt3DRender/QCameraSelector>
      #include <Qt3DRender/QPhongMaterial>
      #include <Qt3DRender/QForwardRenderer>
      #include <qmath.h>

      using namespace Qt3DCore;
      using namespace Qt3DRender;

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

          Window view;
          Qt3DCore::QAspectEngine engine;
          engine.registerAspect(new Qt3DRender::QRenderAspect());
          Qt3DInput::QInputAspect *input = new Qt3DInput::QInputAspect;
          engine.registerAspect(input);
          QVariantMap data;
          data.insert(QStringLiteral("surface"), QVariant::fromValue(static_cast<QSurface *>(&view)));
          data.insert(QStringLiteral("eventSource"), QVariant::fromValue(&view));
          engine.setData(data);
          QEntity *root = new QEntity();

          // Camera
          QCamera *cameraEntity = new QCamera(root);
          cameraEntity->setObjectName(QStringLiteral("cameraEntity"));
          cameraEntity->lens()->setPerspectiveProjection(45.0f, 16.0f/9.0f, 0.1f, 1000.0f);
          cameraEntity->setPosition(QVector3D(0, -250.0f, -50.0f));
          cameraEntity->setUpVector(QVector3D(0, 1, 0));
          cameraEntity->setViewCenter(QVector3D(0, 0, 0));
          input->setCamera(cameraEntity);

          // FrameGraph
          QFrameGraph *frameGraph = new QFrameGraph();
          QForwardRenderer *forwardRenderer = new QForwardRenderer();
          forwardRenderer->setCamera(cameraEntity);
          forwardRenderer->setClearColor(Qt::black);
          frameGraph->setActiveFrameGraph(forwardRenderer);
          root->addComponent(frameGraph);

          const float radius = 100.0f;
          const int max = 1000;
          const float det = 1.0f / max;

          // Scene
          for (int i = 0; i < max; i++) {
              Entity *e = new Entity();
              const float angle = M_PI * 2.0f * i * det * 10.;

              e->setDiffuseColor(QColor(qFabs(qCos(angle)) * 255, 204, 75));
              e->setPosition(QVector3D(radius * qCos(angle), 200.* i * det, radius * qSin(angle)));
              e->setTheta(30.0f * i);
              e->setPhi(45.0f * i);

              QPropertyAnimation *animX = new QPropertyAnimation(e, QByteArrayLiteral("theta"));
              animX->setDuration(2400 * (i + 1));
              animX->setStartValue(QVariant::fromValue(i * 30.0f));
              animX->setEndValue(QVariant::fromValue((i + 1) * 390.0f));
              animX->setLoopCount(-1);
              animX->start();

              QPropertyAnimation *animZ = new QPropertyAnimation(e, QByteArrayLiteral("phi"));
              animZ->setDuration(2400 * (i + 1));
              animZ->setStartValue(QVariant::fromValue(i * 20.0f));
              animZ->setEndValue(QVariant::fromValue((i + 1) * 380.0f));
              animZ->setLoopCount(-1);
              animZ->start();

              e->setParent(root);
          }

          engine.setRootEntity(root);
          view.show();

          if (app.arguments().contains(("--bench")))
              QTimer::singleShot(25 * 1000, &app, &QCoreApplication::quit);

          return app.exec();
      }