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**
** Copyright (C) 2013 Digia Plc
** All rights reserved.
** For any questions to Digia, please use contact form at http://qt.digia.com
**
** This file is part of the QtDataVisualization module.
**
** Licensees holding valid Qt Enterprise licenses may use this file in
** accordance with the Qt Enterprise License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.
**
** If you have questions regarding the use of this file, please use
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#include <qmath.h>

#include "datavisualizationglobal_p.h"

#include "q3dscene.h"
#include "q3dscene_p.h"
#include "q3dcamera_p.h"
#include "q3dlight_p.h"

QT_DATAVISUALIZATION_BEGIN_NAMESPACE
/*!
 * \class Q3DScene
 * \inmodule QtDataVisualization
 * \brief Q3DScene class provides description of the 3D scene being visualized.
 * \since 1.0.0
 *
 * The 3D scene contains a single active camera and a single active light source.
 * Visualized data is assumed to be at a fixed location.
 *
 * The 3D scene also keeps track of the viewport in which visualization rendering is done,
 * the primary subviewport inside the viewport where the main 3D data visualization view resides
 * and the secondary subviewport where the 2D sliced view of the data resides.
 *
 * Also the scene has flag for tracking if the secondary 2D slicing view is currently active or not.
 * \note Not all visualizations support the secondary 2D slicing view.
 */

/*!
 * Constructs a basic scene with one light and one camera in it. An
 * optional \a parent parameter can be given and is then passed to QObject constructor.
 */
Q3DScene::Q3DScene(QObject *parent) :
    QObject(parent),
    d_ptr(new Q3DScenePrivate(this))
{
    setActiveCamera(new Q3DCamera(0));
    setActiveLight(new Q3DLight(0));
}

/*!
 * Destroys the 3D scene and all the objects contained within it.
 */
Q3DScene::~Q3DScene()
{
}

/*!
 * \property Q3DScene::viewport
 *
 * This property contains the current viewport rectangle where all 3D rendering
 * is targeted.
 */
QRect Q3DScene::viewport() const
{
    return d_ptr->m_viewport;
}

void Q3DScene::setViewport(const QRect &viewport)
{
    if (d_ptr->m_viewport.width() != viewport.width()
            || d_ptr->m_viewport.height() != viewport.height()) {
        d_ptr->m_viewport = viewport;
        d_ptr->m_viewport.setX(0);
        d_ptr->m_viewport.setY(0);
        d_ptr->m_changeTracker.viewportChanged = true;
        emit viewportChanged(viewport);
    }
}

/*!
 * Sets the \a width and \a height of the viewport only, without changing its location.
 */
void Q3DScene::setViewportSize(int width, int height)
{
    if (d_ptr->m_viewport.width() != width
            || d_ptr->m_viewport.height() != height) {
        d_ptr->m_viewport.setWidth(width);
        d_ptr->m_viewport.setHeight(height);
        d_ptr->m_changeTracker.viewportChanged = true;
        emit viewportChanged(d_ptr->m_viewport);
    }
}

/*!
 * \property Q3DScene::primarySubViewport
 *
 * This property contains the current main viewport rectangle inside the viewport where the
 * primary view of the data visualization is targeted to.
 */
QRect Q3DScene::primarySubViewport() const
{
    return d_ptr->m_primarySubViewport;
}

void Q3DScene::setPrimarySubViewport(const QRect &primarySubViewport)
{
    if (d_ptr->m_primarySubViewport != primarySubViewport) {
        d_ptr->m_primarySubViewport = primarySubViewport;
        d_ptr->m_changeTracker.primarySubViewportChanged = true;
        emit primarySubViewportChanged(primarySubViewport);
    }
}

/*!
 * Returns whether the given \a point resides inside the primary subview or not.
 * The method takes care of correctly mapping between OpenGL coordinates used in the
 * viewport definitions and the Qt event coordinate system used in the input system.
 * \return true if the point is inside the primary subview.
 */
bool Q3DScene::isPointInPrimarySubView(const QPoint &point)
{
    // TODO: Needs fixing. Doesn't respect whether slice or main view is on top or if slicing is even activated currently.
    int x = point.x();
    int y = point.y();
    int areaMinX = d_ptr->m_primarySubViewport.x();
    int areaMaxX = d_ptr->m_primarySubViewport.x() + d_ptr->m_primarySubViewport.width();
    int areaMaxY = d_ptr->m_viewport.height() - d_ptr->m_primarySubViewport.y();
    int areaMinY = d_ptr->m_viewport.height() - (d_ptr->m_primarySubViewport.y() + d_ptr->m_primarySubViewport.height());

    return ( x > areaMinX && x < areaMaxX && y > areaMinY && y < areaMaxY );
}

/*!
 * Returns whether the given \a point resides inside the secondary subview or not.
 * The method takes care of correctly mapping between OpenGL coordinates used in the
 * viewport definitions and the Qt event coordinate system used in the input system.
 * \return true if the point is inside the secondary subview.
 */
bool Q3DScene::isPointInSecondarySubView(const QPoint &point)
{
    // TODO: Needs fixing. Doesn't respect whether slice or main view is on top or if slicing is even activated currently.
    int x = point.x();
    int y = point.y();
    int areaMinX = d_ptr->m_secondarySubViewport.x();
    int areaMaxX = d_ptr->m_secondarySubViewport.x() + d_ptr->m_secondarySubViewport.width();
    int areaMaxY = d_ptr->m_viewport.height() - d_ptr->m_secondarySubViewport.y();
    int areaMinY = d_ptr->m_viewport.height() - (d_ptr->m_secondarySubViewport.y() + d_ptr->m_secondarySubViewport.height());

    return ( x > areaMinX && x < areaMaxX && y > areaMinY && y < areaMaxY );
}

/*!
 * \property Q3DScene::secondarySubViewport
 *
 * This property contains the secondary viewport rectangle inside the viewport. The secondary
 * viewport is used for drawing the 2D slice view in some visualizations.
 */
QRect Q3DScene::secondarySubViewport() const
{
    return d_ptr->m_secondarySubViewport;
}

void Q3DScene::setSecondarySubViewport(const QRect &secondarySubViewport)
{
    if (d_ptr->m_secondarySubViewport != secondarySubViewport) {
        d_ptr->m_secondarySubViewport = secondarySubViewport;
        d_ptr->m_changeTracker.secondarySubViewportChanged = true;
        emit secondarySubViewportChanged(secondarySubViewport);
    }
}

/*!
 * \property Q3DScene::slicingActive
 *
 * This property contains whether 2D slicing view is currently active or not.
 * \note Not all visualizations support the 2D slicing view.
 */
bool Q3DScene::isSlicingActive() const
{
    return d_ptr->m_isSlicingActive;
}

void Q3DScene::setSlicingActive(bool isSlicing)
{
    if (d_ptr->m_isSlicingActive != isSlicing) {
        d_ptr->m_isSlicingActive = isSlicing;
        d_ptr->m_changeTracker.slicingActivatedChanged = true;
        emit slicingActiveChanged(isSlicing);
        emitNeedRender();
    }
}

/*!
 * \property Q3DScene::activeCamera
 *
 * This property contains the currently active camera in the 3D scene.
 * When a new Q3DCamera objects is set in the property it gets automatically added as child of the scene.
 */
Q3DCamera *Q3DScene::activeCamera() const
{
    return d_ptr->m_camera;
}

void Q3DScene::setActiveCamera(Q3DCamera *camera)
{
    Q_ASSERT(camera);

    // Add new camera as child of the scene
    if (camera->parent() != this)
        camera->setParent(this);

    if (camera != d_ptr->m_camera) {
        if (d_ptr->m_camera) {
            disconnect(d_ptr->m_camera, &Q3DCamera::xRotationChanged, this,
                    &Q3DScene::emitNeedRender);
            disconnect(d_ptr->m_camera, &Q3DCamera::yRotationChanged, this,
                    &Q3DScene::emitNeedRender);
        }

        d_ptr->m_camera = camera;
        d_ptr->m_changeTracker.cameraChanged = true;

        if (camera) {
            connect(camera, &Q3DCamera::xRotationChanged, this,
                    &Q3DScene::emitNeedRender);
            connect(camera, &Q3DCamera::yRotationChanged, this,
                    &Q3DScene::emitNeedRender);
        }

        emit activeCameraChanged(camera);
        emitNeedRender();
    }
}

void Q3DScene::emitNeedRender()
{
    emit needRender();
}

/*!
 * \property Q3DScene::activeLight
 *
 * This property contains the currently active light in the 3D scene.
 * When a new Q3DLight objects is set in the property it gets automatically added as child of the scene.
 */
Q3DLight *Q3DScene::activeLight() const
{
    return d_ptr->m_light;
}

void Q3DScene::setActiveLight(Q3DLight *light)
{
    Q_ASSERT(light);

    // Add new light as child of the scene
    if (light->parent() != this)
        light->setParent(this);

    if (light != d_ptr->m_light) {
        d_ptr->m_light = light;
        d_ptr->m_changeTracker.lightChanged = true;
        emit activeLightChanged(light);
    }
}

/*!
 * \property Q3DScene::devicePixelRatio
 *
 * This property contains the current device pixel ratio that is used when mapping input
 * coordinates to pixel coordinates.
 */
qreal Q3DScene::devicePixelRatio() const
{
    return d_ptr->m_devicePixelRatio;
}

void Q3DScene::setDevicePixelRatio(qreal pixelRatio)
{
    if (d_ptr->m_devicePixelRatio != pixelRatio) {
        d_ptr->m_devicePixelRatio = pixelRatio;
        emit devicePixelRatioChanged(pixelRatio);
    }
}

/*!
 * Calculates and sets the light position relative to the currently active camera using the given parameters.
 * \a relativePosition defines the relative 3D offset to the current camera position.
 * Optional \a fixedRotation fixes the light rotation around the data visualization area to the given value in degrees.
 * Optional \a distanceModifier modifies the distance of the light from the data visualization.
 */
void Q3DScene::setLightPositionRelativeToCamera(const QVector3D &relativePosition,
                                                qreal fixedRotation, qreal distanceModifier)
{
    d_ptr->m_light->setPosition(
                d_ptr->m_camera->calculatePositionRelativeToCamera(relativePosition,
                                                                   fixedRotation,
                                                                   distanceModifier));
}

/*!
 * \fn Q3DScene::needRender()
 * \internal
 */

Q3DScenePrivate::Q3DScenePrivate(Q3DScene *q) :
    q_ptr(q),
    m_devicePixelRatio(1.f),
    m_camera(),
    m_light(),
    m_isUnderSideCameraEnabled(false),
    m_isSlicingActive(false)
{
}

Q3DScenePrivate::~Q3DScenePrivate()
{
    delete m_camera;
    delete m_light;
}

// Copies changed values from this scene to the other scene. If the other scene had same changes,
// those changes are discarded.
void Q3DScenePrivate::sync(Q3DScenePrivate &other)
{
    if (m_changeTracker.viewportChanged) {
        other.q_ptr->setViewport(q_ptr->viewport());
        m_changeTracker.viewportChanged = false;
        other.m_changeTracker.viewportChanged = false;
    }
    if (m_changeTracker.primarySubViewportChanged) {
        other.q_ptr->setPrimarySubViewport(q_ptr->primarySubViewport());
        m_changeTracker.primarySubViewportChanged = false;
        other.m_changeTracker.primarySubViewportChanged = false;
    }
    if (m_changeTracker.secondarySubViewportChanged) {
        other.q_ptr->setSecondarySubViewport(q_ptr->secondarySubViewport());
        m_changeTracker.secondarySubViewportChanged = false;
        other.m_changeTracker.secondarySubViewportChanged = false;
    }
    if (m_changeTracker.cameraChanged) {
        m_camera->setDirty(true);
        m_changeTracker.cameraChanged = false;
        other.m_changeTracker.cameraChanged = false;
    }
    m_camera->d_ptr->sync(*other.m_camera);

    if (m_changeTracker.lightChanged) {
        m_light->setDirty(true);
        m_changeTracker.lightChanged = false;
        other.m_changeTracker.lightChanged = false;
    }
    m_light->d_ptr->sync(*other.m_light);

    if (m_changeTracker.slicingActivatedChanged) {
        other.q_ptr->setSlicingActive(q_ptr->isSlicingActive());
        m_changeTracker.slicingActivatedChanged = false;
        other.m_changeTracker.slicingActivatedChanged = false;
    }

    if (m_changeTracker.devicePixelRatioChanged) {
        other.q_ptr->setDevicePixelRatio(q_ptr->devicePixelRatio());
        m_changeTracker.devicePixelRatioChanged = false;
        other.m_changeTracker.devicePixelRatioChanged = false;
    }
}

QT_DATAVISUALIZATION_END_NAMESPACE