Enable mercator-to-screen projection in GLSL

With this change, all the geo-to-screen conversion,
and the triangulation operations for geo polylines
and geo polygon are performed either at set time
or in the shader.
A separate bounding box geometry is processed
in the old way to provide a correct QtQuick Item
geometry, that can be used for nesting mouse areas,
performing translations, input event delivery, etc.

With this approach, performance are improved by more
than one order of magnitude in average, but complex
geometries will of course benefit more.

It also adds correct rendering support for polygons
with holes, previously only rendered correctly
by the MapboxGL plugin.

The polyline shader has basic miter joins. The miter is
skipped if the angle is too sharp to avoid complicating
the implementation.
This shader introduces some glitches when the polyline
is minified, for which the real fix is to
have LOD for the geometry, and render simplified
geometries at low zoom levels (added in a subsequent patch).

Note: this approach, at least in its current implementation,
does not support enabling layers on individual items, only
on the Map element.

Task-number: QTBUG-49303
Task-number: QTBUG-38459
Change-Id: I0c2dc0bf364d32f74ca7c4014f6d66e6219c8ae4
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

1 files changed, 823 insertions, 0 deletions

diff --git a/src/location/declarativemaps/qdeclarativepolylinemapitem_p_p.h b/src/location/declarativemaps/qdeclarativepolylinemapitem_p_p.h
new file mode 100644
index 00000000..d37f77ad
--- /dev/null
+++ b/src/location/declarativemaps/qdeclarativepolylinemapitem_p_p.h
@@ -0,0 +1,823 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 Paolo Angelelli <paolo.angelelli@gmail.com>
+** Copyright (C) 2020 The Qt Company Ltd.
+** 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QDECLARATIVEPOLYLINEMAPITEM_P_P_H
+#define QDECLARATIVEPOLYLINEMAPITEM_P_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 <QtLocation/private/qlocationglobal_p.h>
+#include <QtLocation/private/qdeclarativepolylinemapitem_p.h>
+#include <QtLocation/private/qdeclarativegeomapitemutils_p.h>
+#include <QtLocation/private/qdeclarativepolylinemapitem_p.h>
+#include <QtLocation/private/qgeomapitemgeometry_p.h>
+#include <QSGGeometryNode>
+#include <QSGFlatColorMaterial>
+#include <QtPositioning/QGeoPath>
+#include <QtPositioning/QGeoPolygon>
+#include <QtPositioning/QGeoRectangle>
+#include <QtPositioning/QGeoCircle>
+#include <QtPositioning/private/qdoublevector2d_p.h>
+#include <QtCore/QScopedValueRollback>
+
+QT_BEGIN_NAMESPACE
+
+class Q_LOCATION_PRIVATE_EXPORT QGeoMapPolylineGeometry : public QGeoMapItemGeometry
+{
+public:
+    QGeoMapPolylineGeometry();
+
+    void updateSourcePoints(const QGeoMap &map,
+                            const QList<QDoubleVector2D> &path,
+                            const QGeoCoordinate geoLeftBound);
+
+    void updateScreenPoints(const QGeoMap &map,
+                            qreal strokeWidth,
+                            bool adjustTranslation = true);
+
+    void clearSource();
+
+    bool contains(const QPointF &point) const override;
+
+    QList<QList<QDoubleVector2D> > clipPath(const QGeoMap &map,
+                    const QList<QDoubleVector2D> &path,
+                    QDoubleVector2D &leftBoundWrapped);
+
+    void pathToScreen(const QGeoMap &map,
+                      const QList<QList<QDoubleVector2D> > &clippedPaths,
+                      const QDoubleVector2D &leftBoundWrapped);
+
+public:
+    QVector<qreal> srcPoints_;
+    QVector<QPainterPath::ElementType> srcPointTypes_;
+
+#ifdef QT_LOCATION_DEBUG
+    QList<QDoubleVector2D> m_wrappedPath;
+    QList<QList<QDoubleVector2D>> m_clippedPaths;
+#endif
+
+    friend class QDeclarativeCircleMapItem;
+    friend class QDeclarativePolygonMapItem;
+    friend class QDeclarativeRectangleMapItem;
+};
+
+class Q_LOCATION_PRIVATE_EXPORT VisibleNode
+{
+public:
+    VisibleNode();
+    virtual ~VisibleNode();
+
+    bool subtreeBlocked() const;
+    void setSubtreeBlocked(bool blocked);
+    bool visible() const;
+    void setVisible(bool visible);
+
+    bool m_blocked : 1;
+    bool m_visible : 1;
+};
+
+class Q_LOCATION_PRIVATE_EXPORT MapItemGeometryNode : public QSGGeometryNode, public VisibleNode
+{
+public:
+    ~MapItemGeometryNode() override;
+    bool isSubtreeBlocked() const override;
+};
+
+class Q_LOCATION_PRIVATE_EXPORT MapPolylineMaterial : public QSGFlatColorMaterial
+{
+public:
+    MapPolylineMaterial()
+        : QSGFlatColorMaterial()
+    {
+        // Passing RequiresFullMatrix is essential in order to prevent the
+        // batch renderer from baking in simple, translate-only transforms into
+        // the vertex data. The shader will rely on the fact that
+        // vertexCoord.xy is the Shape-space coordinate and so no modifications
+        // are welcome.
+        setFlag(Blending | RequiresFullMatrix | CustomCompileStep);
+    }
+
+    QSGMaterialShader *createShader() const override;
+
+    void setGeoProjection(const QMatrix4x4 &p)
+    {
+        m_geoProjection = p;
+    }
+
+    QMatrix4x4 geoProjection() const
+    {
+        return m_geoProjection;
+    }
+
+    void setCenter(const QDoubleVector3D &c)
+    {
+        m_center = c;
+    }
+
+    QDoubleVector3D center() const
+    {
+        return m_center;
+    }
+
+    void setColor(const QColor &color)
+    {
+        QSGFlatColorMaterial::setColor(color);
+        setFlag(Blending, true); // ToDo: Needed only temporarily, can be removed after debugging
+    }
+
+    int wrapOffset() const
+    {
+        return m_wrapOffset;
+    }
+
+    void setWrapOffset(int wrapOffset)
+    {
+        m_wrapOffset = wrapOffset;
+    }
+
+    void setLineWidth(const float lw)
+    {
+        m_lineWidth = lw;
+    }
+
+    float lineWidth() const
+    {
+        return m_lineWidth;
+    }
+
+    QSGMaterialType *type() const override;
+    int compare(const QSGMaterial *other) const override;
+
+protected:
+    QMatrix4x4 m_geoProjection;
+    QDoubleVector3D m_center;
+    int m_wrapOffset = 0;
+    float m_lineWidth = 1.0;
+};
+
+class Q_LOCATION_PRIVATE_EXPORT MapPolylineNode : public MapItemGeometryNode
+{
+public:
+    MapPolylineNode();
+    ~MapPolylineNode() override;
+
+    void update(const QColor &fillColor, const QGeoMapItemGeometry *shape);
+
+protected:
+    QSGFlatColorMaterial fill_material_;
+    QSGGeometry geometry_;
+};
+
+class Q_LOCATION_PRIVATE_EXPORT QGeoMapPolylineGeometryOpenGL : public QGeoMapItemGeometry
+{
+public:
+    typedef struct {
+        QList<QDoubleVector2D> wrappedBboxes;
+    } WrappedPolyline;
+
+    QGeoMapPolylineGeometryOpenGL() {}
+
+    void updateSourcePoints(const QGeoMap &map,
+                            const QGeoPolygon &poly);
+
+    void updateSourcePoints(const QGeoMap &map,
+                            const QGeoPath &poly);
+
+    void updateSourcePoints(const QGeoProjectionWebMercator &p,
+                            const QList<QDoubleVector2D> &wrappedPath,
+                            const QGeoRectangle &boundingRectangle);
+
+    void updateSourcePoints(const QGeoMap &map,
+                            const QGeoRectangle &rect);
+
+    void updateSourcePoints(const QGeoMap &map,
+                            const QGeoCircle &circle);
+
+    void updateScreenPoints(const QGeoMap &map,
+                            qreal strokeWidth,
+                            bool adjustTranslation = true);
+
+    void updateQuickGeometry(const QGeoProjectionWebMercator &p, qreal strokeWidth = 0.0);
+
+    void allocateAndFillEntries(QSGGeometry *geom, bool closed = false) const;
+    void allocateAndFillLineStrip(QSGGeometry *geom) const;
+
+    bool contains(const QPointF &point) const override
+    {
+        Q_UNUSED(point)
+        return false;
+    }
+
+    static double distanceTo(const QDoubleVector2D &a, const QDoubleVector2D &b, const QDoubleVector2D &p)
+    {
+        double u = ((p.x() - a.x()) * (b.x() - a.x()) + (p.y() - a.y()) * (b.y() - a.y()) ) / (b - a).lengthSquared();
+        QDoubleVector2D intersection(a.x() + u * (b.x() - a.x()) , a.y() + u * (b.y() - a.y()) );
+
+        QDoubleVector2D candidate = ( (p-a).length() < (p-b).length() ) ? a : b;
+
+        if (u > 0 && u < 1
+            && (p-intersection).length() < (p-candidate).length()  ) // And it falls in the segment
+                candidate = intersection;
+
+        return qAbs((candidate - p).length());
+    }
+    // Note: this is also slightly incorrect on joins and in the beginning/end of the line
+    bool contains(const QPointF &point, qreal lineWidth, const QGeoProjectionWebMercator &p) const
+    {
+        const double lineHalfWidth = lineWidth * 0.5;
+        const QDoubleVector2D pt(point);
+        QDoubleVector2D a;
+        if (m_screenVertices.size()) a = p.wrappedMapProjectionToItemPosition(p.wrapMapProjection(m_screenVertices.first().toDoubleVector2D()));
+        QDoubleVector2D b;
+        for (int i = 1; i < m_screenVertices.size(); ++i)
+        {
+            if (!a.isFinite()) {
+                a = p.wrappedMapProjectionToItemPosition(p.wrapMapProjection(m_screenVertices.at(i).toDoubleVector2D()));
+                continue;
+            }
+
+            b = p.wrappedMapProjectionToItemPosition(p.wrapMapProjection(m_screenVertices.at(i).toDoubleVector2D()));
+            if (!b.isFinite()) {
+                a = b;
+                continue;
+            }
+
+            if (b == a)
+                continue;
+
+            // Heavily simplifying it here: if a point is not projectable, skip the segment.
+            // For a correct solution, the segment should be clipped instead.
+            if (distanceTo(a, b, pt) <= lineHalfWidth)
+                return true;
+
+            a = b;
+        }
+        return false;
+    }
+
+public:
+    QVector<QDeclarativeGeoMapItemUtils::vec2> m_screenVertices;
+    QDoubleVector2D m_bboxLeftBoundWrapped;
+    QVector<WrappedPolyline> m_wrappedPolygons;
+    int m_wrapOffset;
+
+    friend class QDeclarativeCircleMapItem;
+    friend class QDeclarativePolygonMapItem;
+    friend class QDeclarativeRectangleMapItem;
+};
+
+class Q_LOCATION_PRIVATE_EXPORT MapPolylineShaderLineStrip : public QSGMaterialShader
+{
+public:
+    MapPolylineShaderLineStrip();
+
+    const char *vertexShader() const override {
+        return
+        "attribute highp vec4 vertex;               \n"
+        "uniform highp mat4 qt_Matrix;              \n"
+        "uniform highp mat4 mapProjection;          \n"
+        "uniform highp vec3 center;                 \n"
+        "uniform highp vec3 center_lowpart;         \n"
+        "uniform lowp float wrapOffset;             \n"
+        "vec4 wrapped(in vec4 v) { return vec4(v.x + wrapOffset, v.y, 0.0, 1.0); }\n"
+        "void main() {                              \n"
+        "    vec4 vtx = wrapped(vertex) - vec4(center, 0.0);   \n"
+        "    vtx = vtx - vec4(center_lowpart, 0.0);   \n"
+        "    gl_Position = qt_Matrix * mapProjection * vtx;      \n"
+        "}";
+    }
+
+    const char *fragmentShader() const {
+        return
+        "uniform lowp vec4 color;                   \n"
+        "void main() {                              \n"
+        "    gl_FragColor = color;                  \n"
+        "}";
+    }
+
+    void updateState(const RenderState &state, QSGMaterial *newEffect, QSGMaterial *oldEffect) override;
+    char const *const *attributeNames() const override;
+
+protected:
+    void initialize() override
+    {
+        m_matrix_id = program()->uniformLocation("qt_Matrix");
+        m_color_id = program()->uniformLocation("color");
+        m_mapProjection_id = program()->uniformLocation("mapProjection");
+        m_center_id = program()->uniformLocation("center");
+        m_center_lowpart_id = program()->uniformLocation("center_lowpart");
+        m_wrapOffset_id = program()->uniformLocation("wrapOffset");
+    }
+    int m_center_id;
+    int m_center_lowpart_id;
+    int m_mapProjection_id;
+    int m_matrix_id;
+    int m_color_id;
+    int m_wrapOffset_id;
+};
+
+class Q_LOCATION_PRIVATE_EXPORT MapPolylineShaderExtruded : public QSGMaterialShader
+{
+public:
+    MapPolylineShaderExtruded();
+
+    // Heavily adapted from https://github.com/mattdesl/webgl-lines/blob/master/projected/vert.glsl,
+    // that is (c) Matt DesLauriers, and released under the MIT license.
+    const char *vertexShaderMiteredSegments() const;
+
+    const char *vertexShader() const override
+    {
+        return vertexShaderMiteredSegments();
+    }
+
+    const char *fragmentShader() const override
+    {
+        return
+        "varying vec4 primitivecolor;           \n"
+        "void main() {                          \n"
+        "    gl_FragColor = primitivecolor;     \n"
+        "}";
+    }
+
+    void updateState(const RenderState &state, QSGMaterial *newEffect, QSGMaterial *oldEffect) override;
+    char const *const *attributeNames() const override;
+
+protected:
+    void initialize() override
+    {
+        m_matrix_id = program()->uniformLocation("qt_Matrix");
+        m_color_id = program()->uniformLocation("color");
+        m_mapProjection_id = program()->uniformLocation("mapProjection");
+        m_center_id = program()->uniformLocation("center");
+        m_center_lowpart_id = program()->uniformLocation("center_lowpart");
+        m_lineWidth_id = program()->uniformLocation("lineWidth");
+        m_aspect_id = program()->uniformLocation("aspect");
+        m_miter_id = program()->uniformLocation("miter");
+        m_wrapOffset_id = program()->uniformLocation("wrapOffset");
+    }
+    int m_center_id;
+    int m_center_lowpart_id;
+    int m_mapProjection_id;
+    int m_matrix_id;
+    int m_color_id;
+    int m_lineWidth_id;
+    int m_aspect_id;
+    int m_miter_id;
+    int m_wrapOffset_id;
+};
+
+class Q_LOCATION_PRIVATE_EXPORT MapPolylineNodeOpenGLLineStrip : public MapItemGeometryNode
+{
+public:
+    MapPolylineNodeOpenGLLineStrip();
+    ~MapPolylineNodeOpenGLLineStrip() override;
+
+    void update(const QColor &fillColor,
+                const qreal lineWidth,
+                const QGeoMapPolylineGeometryOpenGL *shape,
+                const QMatrix4x4 &geoProjection,
+                const QDoubleVector3D &center,
+                const Qt::PenCapStyle capStyle = Qt::SquareCap);
+
+protected:
+    MapPolylineMaterial fill_material_;
+    QSGGeometry geometry_;
+};
+
+class Q_LOCATION_PRIVATE_EXPORT MapPolylineMaterialExtruded : public MapPolylineMaterial
+{
+public:
+    MapPolylineMaterialExtruded() : MapPolylineMaterial()
+    {
+
+    }
+    QSGMaterialShader *createShader() const override;
+
+    void setMiter(const int m)
+    {
+        m_miter = m;
+    }
+
+    int miter() const
+    {
+        return m_miter;
+    }
+
+    QSGMaterialType *type() const override;
+    int compare(const QSGMaterial *other) const override;
+
+    int m_miter = 0;
+};
+
+class Q_LOCATION_PRIVATE_EXPORT MapPolylineNodeOpenGLExtruded : public MapItemGeometryNode
+{
+public:
+
+    typedef struct {
+         QDeclarativeGeoMapItemUtils::vec2 pos;
+         QDeclarativeGeoMapItemUtils::vec2 prev;
+         QDeclarativeGeoMapItemUtils::vec2 next;
+         float direction;
+         float triangletype; // es2 does not support int attribs
+         float vertextype;
+
+         static const char * const *attributeNames()
+         {
+             static char const *const attr[] = { "vertex", "previous", "next", "direction", "triangletype", "vertextype", nullptr };
+             return attr;
+         }
+         static const QSGGeometry::AttributeSet &attributes()
+         {
+             static const QSGGeometry::Attribute dataTri[] = {
+                 QSGGeometry::Attribute::createWithAttributeType(0, 2, QSGGeometry::FloatType, QSGGeometry::PositionAttribute) // pos
+                 ,QSGGeometry::Attribute::createWithAttributeType(1, 2, QSGGeometry::FloatType, QSGGeometry::UnknownAttribute) // next
+                 ,QSGGeometry::Attribute::createWithAttributeType(2, 2, QSGGeometry::FloatType, QSGGeometry::UnknownAttribute) // previous
+                 ,QSGGeometry::Attribute::createWithAttributeType(3, 1, QSGGeometry::FloatType, QSGGeometry::UnknownAttribute)  // direction
+                 ,QSGGeometry::Attribute::createWithAttributeType(4, 1, QSGGeometry::FloatType, QSGGeometry::UnknownAttribute)  // triangletype
+                 ,QSGGeometry::Attribute::createWithAttributeType(5, 1, QSGGeometry::FloatType, QSGGeometry::UnknownAttribute)  // vertextype
+             };
+             static const QSGGeometry::AttributeSet attrsTri = { 6, sizeof(MapPolylineNodeOpenGLExtruded::MapPolylineEntry), dataTri };
+             return attrsTri;
+         }
+    } MapPolylineEntry;
+
+    MapPolylineNodeOpenGLExtruded();
+    ~MapPolylineNodeOpenGLExtruded() override;
+
+    void update(const QColor &fillColor,
+                const float lineWidth,
+                const QGeoMapPolylineGeometryOpenGL *shape,
+                const QMatrix4x4 geoProjection,
+                const QDoubleVector3D center,
+                const Qt::PenCapStyle capStyle = Qt::FlatCap,
+                bool closed = false);
+
+    static const QSGGeometry::AttributeSet &attributesMapPolylineTriangulated();
+
+protected:
+    MapPolylineMaterialExtruded fill_material_;
+    QSGGeometry m_geometryTriangulating;
+};
+
+class Q_LOCATION_PRIVATE_EXPORT QDeclarativePolylineMapItemPrivate
+{
+public:
+    QDeclarativePolylineMapItemPrivate(QDeclarativePolylineMapItem &poly) : m_poly(poly)
+    {
+
+    }
+    QDeclarativePolylineMapItemPrivate(QDeclarativePolylineMapItemPrivate &other) : m_poly(other.m_poly)
+    {
+    }
+
+    virtual ~QDeclarativePolylineMapItemPrivate();
+    virtual void markSourceDirtyAndUpdate() = 0;
+    virtual void onMapSet() = 0;
+    virtual void onLinePropertiesChanged() = 0;
+    virtual void onGeoGeometryChanged() = 0;
+    virtual void onGeoGeometryUpdated() = 0;
+    virtual void onItemGeometryChanged() = 0;
+    virtual void updatePolish() = 0;
+    virtual void afterViewportChanged() = 0;
+    virtual QSGNode * updateMapItemPaintNode(QSGNode *oldNode, QQuickItem::UpdatePaintNodeData *data) = 0;
+    virtual bool contains(const QPointF &point) const = 0;
+
+    QDeclarativePolylineMapItem &m_poly;
+    Qt::PenStyle m_penStyle = Qt::SolidLine;
+    Qt::PenCapStyle m_penCapStyle = Qt::SquareCap;
+};
+
+class Q_LOCATION_PRIVATE_EXPORT QDeclarativePolylineMapItemPrivateCPU: public QDeclarativePolylineMapItemPrivate
+{
+public:
+    QDeclarativePolylineMapItemPrivateCPU(QDeclarativePolylineMapItem &poly) : QDeclarativePolylineMapItemPrivate(poly)
+    {
+    }
+
+    QDeclarativePolylineMapItemPrivateCPU(QDeclarativePolylineMapItemPrivate &other)
+    : QDeclarativePolylineMapItemPrivate(other)
+    {
+    }
+
+    ~QDeclarativePolylineMapItemPrivateCPU() override;
+    void onLinePropertiesChanged() override
+    {
+        // mark dirty just in case we're a width change
+        markSourceDirtyAndUpdate();
+    }
+    void markSourceDirtyAndUpdate() override
+    {
+        m_geometry.markSourceDirty();
+        m_poly.polishAndUpdate();
+    }
+    void regenerateCache()
+    {
+        if (!m_poly.map() || m_poly.map()->geoProjection().projectionType() != QGeoProjection::ProjectionWebMercator)
+            return;
+        const QGeoProjectionWebMercator &p = static_cast<const QGeoProjectionWebMercator&>(m_poly.map()->geoProjection());
+        m_geopathProjected.clear();
+        m_geopathProjected.reserve(m_poly.m_geopath.size());
+        for (const QGeoCoordinate &c : m_poly.m_geopath.path())
+            m_geopathProjected << p.geoToMapProjection(c);
+    }
+    void updateCache()
+    {
+        if (!m_poly.map() || m_poly.map()->geoProjection().projectionType() != QGeoProjection::ProjectionWebMercator)
+            return;
+        const QGeoProjectionWebMercator &p = static_cast<const QGeoProjectionWebMercator&>(m_poly.map()->geoProjection());
+        m_geopathProjected << p.geoToMapProjection(m_poly.m_geopath.path().last());
+    }
+    void preserveGeometry()
+    {
+        m_geometry.setPreserveGeometry(true, m_poly.m_geopath.boundingGeoRectangle().topLeft());
+    }
+    void afterViewportChanged() override
+    {
+        // preserveGeometry is cleared in updateMapItemPaintNode
+        preserveGeometry();
+        markSourceDirtyAndUpdate();
+    }
+    void onMapSet() override
+    {
+        regenerateCache();
+        markSourceDirtyAndUpdate();
+    }
+    void onGeoGeometryChanged() override
+    {
+        regenerateCache();
+        preserveGeometry();
+        markSourceDirtyAndUpdate();
+    }
+    void onGeoGeometryUpdated() override
+    {
+        updateCache();
+        preserveGeometry();
+        markSourceDirtyAndUpdate();
+    }
+    void onItemGeometryChanged() override
+    {
+        onGeoGeometryChanged();
+    }
+    void updatePolish() override
+    {
+        if (m_poly.m_geopath.path().length() < 2) { // Possibly cleared
+            m_geometry.clear();
+            m_poly.setWidth(0);
+            m_poly.setHeight(0);
+            return;
+        }
+        QScopedValueRollback<bool> rollback(m_poly.m_updatingGeometry);
+        m_poly.m_updatingGeometry = true;
+
+        const QGeoMap *map = m_poly.map();
+        const qreal borderWidth = m_poly.m_line.width();
+
+        m_geometry.updateSourcePoints(*map, m_geopathProjected, m_poly.m_geopath.boundingGeoRectangle().topLeft());
+        m_geometry.updateScreenPoints(*map, borderWidth);
+
+        m_poly.setWidth(m_geometry.sourceBoundingBox().width() + borderWidth);
+        m_poly.setHeight(m_geometry.sourceBoundingBox().height() + borderWidth);
+
+        m_poly.setPositionOnMap(m_geometry.origin(), -1 * m_geometry.sourceBoundingBox().topLeft()
+                                + QPointF(borderWidth, borderWidth) * 0.5 ); // it has to be shifted so that the center of the line is on the correct geocoord
+    }
+    QSGNode *updateMapItemPaintNode(QSGNode *oldNode, QQuickItem::UpdatePaintNodeData * /*data*/) override
+    {
+        if (!m_node || !oldNode) {
+            m_node = new MapPolylineNode();
+            if (oldNode) {
+                delete oldNode;
+                oldNode = nullptr;
+            }
+        } else {
+            m_node = static_cast<MapPolylineNode *>(oldNode);
+        }
+
+        //TODO: update only material
+        if (m_geometry.isScreenDirty() || m_poly.m_dirtyMaterial || !oldNode) {
+            m_node->update(m_poly.m_line.color(), &m_geometry);
+            m_geometry.setPreserveGeometry(false);
+            m_geometry.markClean();
+            m_poly.m_dirtyMaterial = false;
+        }
+        return m_node;
+    }
+    bool contains(const QPointF &point) const override
+    {
+        return m_geometry.contains(point);
+    }
+
+    QList<QDoubleVector2D> m_geopathProjected;
+    QGeoMapPolylineGeometry m_geometry;
+    MapPolylineNode *m_node = nullptr;
+};
+
+class Q_LOCATION_PRIVATE_EXPORT QDeclarativePolylineMapItemPrivateOpenGLLineStrip: public QDeclarativePolylineMapItemPrivate
+{
+public:
+
+    QDeclarativePolylineMapItemPrivateOpenGLLineStrip(QDeclarativePolylineMapItem &poly) : QDeclarativePolylineMapItemPrivate(poly)
+    {
+    }
+
+    QDeclarativePolylineMapItemPrivateOpenGLLineStrip(QDeclarativePolylineMapItemPrivate &other)
+    : QDeclarativePolylineMapItemPrivate(other)
+    {
+    }
+
+    ~QDeclarativePolylineMapItemPrivateOpenGLLineStrip() override;
+    void onLinePropertiesChanged() override
+    {
+        afterViewportChanged();
+    }
+    void markSourceDirtyAndUpdate() override
+    {
+        m_geometry.markSourceDirty();
+        m_poly.polishAndUpdate();
+    }
+    void preserveGeometry()
+    {
+        m_geometry.setPreserveGeometry(true, m_poly.m_geopath.boundingGeoRectangle().topLeft());
+    }
+    void onMapSet() override
+    {
+        markSourceDirtyAndUpdate();
+    }
+    void onGeoGeometryChanged() override
+    {
+        preserveGeometry();
+        markSourceDirtyAndUpdate();
+    }
+    void onGeoGeometryUpdated() override
+    {
+        preserveGeometry();
+        markSourceDirtyAndUpdate();
+    }
+    void onItemGeometryChanged() override
+    {
+        onGeoGeometryChanged();
+    }
+    void afterViewportChanged() override
+    {
+        preserveGeometry();
+        m_poly.polishAndUpdate();
+    }
+    bool contains(const QPointF &point) const override
+    {
+        return m_geometry.contains(m_poly.mapToItem(m_poly.quickMap(), point),
+                                   m_poly.line()->width(),
+                                   static_cast<const QGeoProjectionWebMercator&>(m_poly.map()->geoProjection()));
+    }
+    void updatePolish() override
+    {
+        if (m_poly.m_geopath.path().length() == 0) { // Possibly cleared
+            m_geometry.clear();
+            m_geometry.clear();
+            m_poly.setWidth(0);
+            m_poly.setHeight(0);
+            return;
+        }
+
+        QScopedValueRollback<bool> rollback(m_poly.m_updatingGeometry);
+        m_poly.m_updatingGeometry = true;
+        const qreal lineWidth = m_poly.m_line.width();
+        m_geometry.updateSourcePoints(*m_poly.map(), m_poly.m_geopath);
+        m_geometry.markScreenDirty();
+        m_geometry.updateScreenPoints(*m_poly.map(), lineWidth);
+
+        m_poly.setWidth(m_geometry.sourceBoundingBox().width());
+        m_poly.setHeight(m_geometry.sourceBoundingBox().height());
+        m_poly.setPosition(1.0 * m_geometry.firstPointOffset() - QPointF(lineWidth * 0.5,lineWidth * 0.5));
+    }
+    QSGNode * updateMapItemPaintNode(QSGNode *oldNode, QQuickItem::UpdatePaintNodeData *data) override
+    {
+        Q_UNUSED(data);
+
+        if (!m_node || !oldNode) {
+            m_node = new MapPolylineNodeOpenGLLineStrip();
+            if (oldNode)
+                delete oldNode;
+        } else {
+            m_node = static_cast<MapPolylineNodeOpenGLLineStrip *>(oldNode);
+        }
+
+        if (m_geometry.isScreenDirty() || m_poly.m_dirtyMaterial) {
+            const QGeoMap *map = m_poly.map();
+            const QMatrix4x4 &combinedMatrix = map->geoProjection().qsgTransform();
+            const QDoubleVector3D &cameraCenter = map->geoProjection().centerMercator();
+            m_node->update(m_poly.m_line.color(), // This updates only the material if the geometry is unchanged
+                           m_poly.m_line.width(),
+                         &m_geometry,
+                         combinedMatrix,
+                         cameraCenter);
+            m_geometry.setPreserveGeometry(false);
+            m_geometry.markClean();
+            m_poly.m_dirtyMaterial = false;
+        }
+        return m_node;
+    }
+
+    QGeoMapPolylineGeometryOpenGL m_geometry;
+    MapPolylineNodeOpenGLLineStrip *m_node = nullptr;
+};
+
+class Q_LOCATION_PRIVATE_EXPORT QDeclarativePolylineMapItemPrivateOpenGLExtruded: public QDeclarativePolylineMapItemPrivateOpenGLLineStrip
+{
+public:
+
+    QDeclarativePolylineMapItemPrivateOpenGLExtruded(QDeclarativePolylineMapItem &poly)
+    : QDeclarativePolylineMapItemPrivateOpenGLLineStrip(poly)
+    {
+    }
+
+    QDeclarativePolylineMapItemPrivateOpenGLExtruded(QDeclarativePolylineMapItemPrivate &other)
+    : QDeclarativePolylineMapItemPrivateOpenGLLineStrip(other)
+    {
+    }
+
+    ~QDeclarativePolylineMapItemPrivateOpenGLExtruded() override;
+
+    QSGNode * updateMapItemPaintNode(QSGNode *oldNode, QQuickItem::UpdatePaintNodeData *data) override
+    {
+        Q_UNUSED(data);
+        const QGeoMap *map = m_poly.map();
+        const QGeoProjectionWebMercator &p = static_cast<const QGeoProjectionWebMercator&>(map->geoProjection());
+        const QMatrix4x4 &combinedMatrix = p.qsgTransform();
+        const QDoubleVector3D &cameraCenter = p.centerMercator();
+        const QColor &color = m_poly.m_line.color();
+        const float lineWidth = m_poly.m_line.width();
+
+        MapPolylineNodeOpenGLExtruded *nodeTri = nullptr;
+        if (!m_nodeTri || !oldNode) {
+            if (oldNode)
+                delete oldNode;
+            nodeTri = new MapPolylineNodeOpenGLExtruded();
+        } else {
+            nodeTri = static_cast<MapPolylineNodeOpenGLExtruded *>(oldNode);
+        }
+
+        //TODO: update only material
+        if (m_geometry.isScreenDirty() || m_poly.m_dirtyMaterial) {
+            nodeTri->update(color,
+                         lineWidth  ,
+                         &m_geometry,
+                         combinedMatrix,
+                         cameraCenter,
+                         m_penCapStyle);
+            m_geometry.setPreserveGeometry(false);
+            m_geometry.markClean();
+            m_poly.m_dirtyMaterial = false;
+        }
+        m_nodeTri = nodeTri;
+        return nodeTri;
+    }
+
+    MapPolylineNodeOpenGLExtruded *m_nodeTri = nullptr;
+};
+
+QT_END_NAMESPACE
+
+#endif // QDECLARATIVEPOLYLINEMAPITEM_P_P_H