/****************************************************************************
**
** Copyright (C) 2014 Klaralvdalens Datakonsult AB (KDAB).
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** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
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** 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
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****************************************************************************/

#include <QGuiApplication>

#include <Qt3DCore/QEntity>
#include <Qt3DCore/QCamera>
#include <Qt3DCore/QCameraLens>
#include <Qt3DCore/QTransform>
#include <Qt3DCore/QAspectEngine>

#include <Qt3DInput/QInputAspect>

#include <Qt3DRender/QRenderAspect>
#include <Qt3DRender/QFrameGraph>
#include <Qt3DRender/QForwardRenderer>
#include <Qt3DRender/QPhongMaterial>
#include <Qt3DRender/QCylinderMesh>
#include <Qt3DRender/QSphereMesh>
#include <Qt3DRender/QTorusMesh>
#include <Qt3DRender/QWindow>

#include <QPropertyAnimation>

class OrbitTransformController : public QObject
{
    Q_OBJECT
    Q_PROPERTY(Qt3DCore::QTransform* target READ target WRITE setTarget NOTIFY targetChanged)
    Q_PROPERTY(float radius READ radius WRITE setRadius NOTIFY radiusChanged)
    Q_PROPERTY(float angle READ angle WRITE setAngle NOTIFY angleChanged)

public:
    OrbitTransformController(QObject *parent = 0)
        : QObject(parent)
        , m_target(Q_NULLPTR)
        , m_matrix()
        , m_radius(1.0f)
        , m_angle(0.0f)
    {
    }

    void setTarget(Qt3DCore::QTransform *target)
    {
        if (m_target != target) {
            m_target = target;
            emit targetChanged();
        }
    }

    Qt3DCore::QTransform *target() const { return m_target; }

    void setRadius(float radius)
    {
        if (!qFuzzyCompare(radius, m_radius)) {
            m_radius = radius;
            updateMatrix();
            emit radiusChanged();
        }
    }

    float radius() const { return m_radius; }

    void setAngle(float angle)
    {
        if (!qFuzzyCompare(angle, m_angle)) {
            m_angle = angle;
            updateMatrix();
            emit angleChanged();
        }
    }

    float angle() const { return m_angle; }

signals:
    void targetChanged();
    void radiusChanged();
    void angleChanged();

protected:
    void updateMatrix()
    {
        m_matrix.setToIdentity();
        m_matrix.rotate(m_angle, QVector3D(0.0f, 1.0f, 0.0f));
        m_matrix.translate(m_radius, 0.0f, 0.0f);
        m_target->setMatrix(m_matrix);
    }

private:
    Qt3DCore::QTransform *m_target;
    QMatrix4x4 m_matrix;
    float m_radius;
    float m_angle;
};

int main(int argc, char* argv[])
{
    QGuiApplication app(argc, argv);
    Qt3DRender::QWindow view;
    Qt3DInput::QInputAspect *input = new Qt3DInput::QInputAspect;
    view.registerAspect(input);

    // Root entity
    Qt3DCore::QEntity *rootEntity = new Qt3DCore::QEntity();

    // Camera
    Qt3DCore::QCamera *cameraEntity = view.defaultCamera();

    cameraEntity->lens()->setPerspectiveProjection(45.0f, 16.0f/9.0f, 0.1f, 1000.0f);
    cameraEntity->setPosition(QVector3D(0, 0, -40.0f));
    cameraEntity->setUpVector(QVector3D(0, 1, 0));
    cameraEntity->setViewCenter(QVector3D(0, 0, 0));
    input->setCamera(cameraEntity);

    // Material
    Qt3DRender::QMaterial *material = new Qt3DRender::QPhongMaterial(rootEntity);

    // Torus
    Qt3DCore::QEntity *torusEntity = new Qt3DCore::QEntity(rootEntity);
    Qt3DRender::QTorusMesh *torusMesh = new Qt3DRender::QTorusMesh;
    torusMesh->setRadius(5);
    torusMesh->setMinorRadius(1);
    torusMesh->setRings(100);
    torusMesh->setSlices(20);

    Qt3DCore::QTransform *torusTransform = new Qt3DCore::QTransform;
    torusTransform->setScale3D(QVector3D(1.5, 1, 0.5));
    torusTransform->setRotation(QQuaternion::fromAxisAndAngle(QVector3D(1, 0, 0), 45.0f));

    torusEntity->addComponent(torusMesh);
    torusEntity->addComponent(torusTransform);
    torusEntity->addComponent(material);

    // Sphere
    Qt3DCore::QEntity *sphereEntity = new Qt3DCore::QEntity(rootEntity);
    Qt3DRender::QSphereMesh *sphereMesh = new Qt3DRender::QSphereMesh;
    sphereMesh->setRadius(3);

    Qt3DCore::QTransform *sphereTransform = new Qt3DCore::QTransform;
    OrbitTransformController *controller = new OrbitTransformController(sphereTransform);
    controller->setTarget(sphereTransform);
    controller->setRadius(20.0f);

    QPropertyAnimation *sphereRotateTransformAnimation = new QPropertyAnimation(sphereTransform);
    sphereRotateTransformAnimation->setTargetObject(controller);
    sphereRotateTransformAnimation->setPropertyName("angle");
    sphereRotateTransformAnimation->setStartValue(QVariant::fromValue(0));
    sphereRotateTransformAnimation->setEndValue(QVariant::fromValue(360));
    sphereRotateTransformAnimation->setDuration(10000);
    sphereRotateTransformAnimation->setLoopCount(-1);
    sphereRotateTransformAnimation->start();

    sphereEntity->addComponent(sphereMesh);
    sphereEntity->addComponent(sphereTransform);
    sphereEntity->addComponent(material);

    view.setRootEntity(rootEntity);
    view.show();

    return app.exec();
}

#include "main.moc"