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/****************************************************************************
**
** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the Qt Mobility Components.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia. For licensing terms and
** conditions see http://qt.digia.com/licensing. For further information
** use the contact form at http://qt.digia.com/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 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights. These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 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 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef MAKEPOLY_P_H
#define MAKEPOLY_P_H
//
// W A R N I N G
// -------------
//
// This file is not part of the Qt API. It exists purely as an
// implementation detail. This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//
#include "qgeotiledmapdata.h"
#include "qgeotiledmapdata_p.h"
#include "qgeocoordinate.h"
#include <QList>
#include <QPolygonF>
#include <QGraphicsPolygonItem>
QTM_BEGIN_NAMESPACE
// TODO: replace boolean parameter by enum
static inline void makepoly(QPolygonF &points, const QList<QGeoCoordinate> & path, const QGeoTiledMapDataPrivate * mapData, bool closedPath, qreal ypole = -100)
{
points.clear();
QGeoCoordinate lastCoord = closedPath ? path.last() : path.first();
QPointF lastPoint = mapData->q_ptr->coordinateToWorldPixel(lastCoord);
int width = mapData->maxZoomSize.width();
for (int i = 0; i < path.size(); ++i) {
const QGeoCoordinate &coord = path.at(i);
if (!coord.isValid())
continue;
const qreal lng = coord.longitude();
const qreal lastLng = lastCoord.longitude();
// is the dateline crossed = different sign AND gap is large enough
const bool crossesDateline = lastLng * lng < 0 && abs(lastLng - lng) > 180;
// calculate base point
QPointF point = mapData->q_ptr->coordinateToWorldPixel(coord);
// if the dateline is crossed, draw "around" the map over the chosen pole
if (crossesDateline) {
// is the shortest route east = dateline crossed XOR longitude is east by simple comparison
const bool goesEast = crossesDateline != (lng > lastLng);
// direction = positive if east, negative otherwise
const qreal dir = goesEast ? 1 : -1;
// lastPoint on this side
const QPointF & L = lastPoint;
// point on the other side
const QPointF & P = point;
// lastPoint on the other side
QPointF L_ = L - QPointF(width * dir, 0);
// point on this side
QPointF P_ = P + QPointF(width * dir, 0);
// TODO: make a better algorithm to make sure the off-screen points P' and L' are far enough from the dateline so the lines to the poles don't flicker through.
// this works for now :)
L_ += (L_ - P) * 7;
P_ += (P_ - L) * 7;
// pole point on this side
QPointF O1 = QPointF(P_.x(), ypole);
// pole point on the other side
QPointF O2 = QPointF(L_.x(), ypole);
//points.append(L); // implicit
points.append(P_); // P'
points.append(O1);
points.append(O2);
points.append(L_); // L'
points.append(P);
} else {
// add point to polygon
points.append(point);
}
lastCoord = coord;
lastPoint = point;
}
}
QTM_END_NAMESPACE
#endif //MAKEPOLY_P_H
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