Mapbox GL plugin for QtLocation

Add Mapbox GL as a plugin for rendering vector tiles
using OpenGL.

Patch by:
- Bruno de Oliveira Abinader <bruno@mapbox.com>
- Thiago Marcos P. Santos <thiago@mapbox.com>

Change-Id: I1671ae4dba0891e280a327543f15e73de1df385d
Reviewed-by: Paolo Angelelli <paolo.angelelli@qt.io>

1 files changed, 215 insertions, 0 deletions

diff --git a/src/plugins/geoservices/mapboxgl/qgeomapmapboxgl.cpp b/src/plugins/geoservices/mapboxgl/qgeomapmapboxgl.cpp
new file mode 100644
index 00000000..16b5fb8b
--- /dev/null
+++ b/src/plugins/geoservices/mapboxgl/qgeomapmapboxgl.cpp
@@ -0,0 +1,215 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Copyright (C) 2017 Mapbox, Inc.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the QtLocation 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
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qgeomapmapboxgl.h"
+#include "qsgmapboxglnode.h"
+
+#include <QtCore/QByteArray>
+#include <QtCore/QCoreApplication>
+#include <QtCore/QTimer>
+#include <QtGui/QOpenGLContext>
+#include <QtGui/QOpenGLFramebufferObject>
+#include <QtLocation/private/qgeomap_p_p.h>
+#include <QtLocation/private/qgeoprojection_p.h>
+#include <QtQuick/QQuickWindow>
+#include <QtQuick/QSGImageNode>
+#include <QtQuick/private/qsgtexture_p.h>
+
+#include <QMapboxGL>
+
+#include <cmath>
+
+// FIXME: Expose from Mapbox GL constants
+#define MBGL_TILE_SIZE 512.0
+
+namespace {
+
+static const double invLog2 = 1.0 / std::log(2.0);
+
+static double zoomLevelFrom256(double zoomLevelFor256, double tileSize)
+{
+    return std::log(std::pow(2.0, zoomLevelFor256) * 256.0 / tileSize) * invLog2;
+}
+
+} // namespace
+
+class QGeoMapMapboxGLPrivate : public QGeoMapPrivate
+{
+    Q_DECLARE_PUBLIC(QGeoMapMapboxGL)
+
+public:
+    QGeoMapMapboxGLPrivate(QGeoMappingManagerEngineMapboxGL *engine);
+
+    ~QGeoMapMapboxGLPrivate();
+
+    QSGNode *updateSceneGraph(QSGNode *oldNode, QQuickWindow *window);
+
+    /* Data members */
+    enum SyncState : int {
+        NoSync = 0,
+        ViewportSync   = 1 << 0,
+        CameraDataSync = 1 << 1,
+        MapTypeSync    = 1 << 2
+    };
+    Q_DECLARE_FLAGS(SyncStates, SyncState);
+
+    QMapboxGLSettings m_settings;
+
+    QTimer m_refresh;
+    bool m_shouldRefresh = true;
+
+    SyncStates m_syncState = NoSync;
+
+protected:
+    void changeViewportSize(const QSize &size) Q_DECL_OVERRIDE;
+    void changeCameraData(const QGeoCameraData &oldCameraData) Q_DECL_OVERRIDE;
+    void changeActiveMapType(const QGeoMapType mapType) Q_DECL_OVERRIDE;
+
+private:
+    Q_DISABLE_COPY(QGeoMapMapboxGLPrivate)
+};
+
+Q_DECLARE_OPERATORS_FOR_FLAGS(QGeoMapMapboxGLPrivate::SyncStates)
+
+QGeoMapMapboxGLPrivate::QGeoMapMapboxGLPrivate(QGeoMappingManagerEngineMapboxGL *engine)
+    : QGeoMapPrivate(engine, new QGeoProjectionWebMercator)
+{
+}
+
+QGeoMapMapboxGLPrivate::~QGeoMapMapboxGLPrivate()
+{
+}
+
+QSGNode *QGeoMapMapboxGLPrivate::updateSceneGraph(QSGNode *oldNode, QQuickWindow *window)
+{
+    Q_Q(QGeoMapMapboxGL);
+
+    static bool warned;
+    if (!warned) {
+        if (window->openglContext()->thread() != QCoreApplication::instance()->thread()) {
+            qWarning() << "Threaded rendering is not supported by Mapbox GL plugin.";
+            QMetaObject::invokeMethod(&m_refresh, "start", Qt::QueuedConnection);
+        }
+
+        warned = true;
+    }
+
+    QSGMapboxGLNode *mbglNode = static_cast<QSGMapboxGLNode *>(oldNode);
+    if (!mbglNode) {
+        mbglNode = new QSGMapboxGLNode(m_settings, m_viewportSize, window->devicePixelRatio(), q);
+        m_syncState = MapTypeSync | CameraDataSync | ViewportSync;
+    }
+
+    QMapboxGL *map = mbglNode->map();
+
+    if (m_syncState & MapTypeSync) {
+        map->setStyleUrl(m_activeMapType.name());
+    }
+
+    if (m_syncState & CameraDataSync) {
+        map->setZoom(zoomLevelFrom256(m_cameraData.zoomLevel() , MBGL_TILE_SIZE));
+        map->setBearing(m_cameraData.bearing());
+        map->setPitch(m_cameraData.tilt());
+
+        QGeoCoordinate coordinate = m_cameraData.center();
+        map->setCoordinate(QMapbox::Coordinate(coordinate.latitude(), coordinate.longitude()));
+    }
+
+    if (m_syncState & ViewportSync) {
+        mbglNode->resize(m_viewportSize, window->devicePixelRatio());
+    }
+
+    mbglNode->render();
+
+    m_syncState = NoSync;
+
+    return mbglNode;
+}
+
+void QGeoMapMapboxGLPrivate::changeViewportSize(const QSize &)
+{
+    Q_Q(QGeoMapMapboxGL);
+
+    m_syncState = m_syncState | ViewportSync;
+    emit q->sgNodeChanged();
+}
+
+void QGeoMapMapboxGLPrivate::changeCameraData(const QGeoCameraData &)
+{
+    Q_Q(QGeoMapMapboxGL);
+
+    m_syncState = m_syncState | CameraDataSync;
+    emit q->sgNodeChanged();
+}
+
+void QGeoMapMapboxGLPrivate::changeActiveMapType(const QGeoMapType)
+{
+    Q_Q(QGeoMapMapboxGL);
+
+    m_syncState = m_syncState | MapTypeSync;
+    emit q->sgNodeChanged();
+}
+
+/*
+ * QGeoMapMapboxGL implementation
+ */
+
+QGeoMapMapboxGL::QGeoMapMapboxGL(QGeoMappingManagerEngineMapboxGL *engine, QObject *parent)
+    :   QGeoMap(*new QGeoMapMapboxGLPrivate(engine), parent), m_engine(engine)
+{
+    Q_D(QGeoMapMapboxGL);
+
+    connect(&d->m_refresh, &QTimer::timeout, this, &QGeoMap::sgNodeChanged);
+    d->m_refresh.setInterval(250);
+}
+
+QGeoMapMapboxGL::~QGeoMapMapboxGL()
+{
+}
+
+void QGeoMapMapboxGL::setMapboxGLSettings(const QMapboxGLSettings& settings)
+{
+    Q_D(QGeoMapMapboxGL);
+
+    d->m_settings = settings;
+}
+
+QSGNode *QGeoMapMapboxGL::updateSceneGraph(QSGNode *oldNode, QQuickWindow *window)
+{
+    Q_D(QGeoMapMapboxGL);
+    return d->updateSceneGraph(oldNode, window);
+}