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       1                 :            : /***************************************************************************
       2                 :            :   qgsvectortilerenderer.h
       3                 :            :   --------------------------------------
       4                 :            :   Date                 : March 2020
       5                 :            :   Copyright            : (C) 2020 by Martin Dobias
       6                 :            :   Email                : wonder dot sk at gmail dot com
       7                 :            :  ***************************************************************************
       8                 :            :  *                                                                         *
       9                 :            :  *   This program is free software; you can redistribute it and/or modify  *
      10                 :            :  *   it under the terms of the GNU General Public License as published by  *
      11                 :            :  *   the Free Software Foundation; either version 2 of the License, or     *
      12                 :            :  *   (at your option) any later version.                                   *
      13                 :            :  *                                                                         *
      14                 :            :  ***************************************************************************/
      15                 :            : 
      16                 :            : #ifndef QGSVECTORTILERENDERER_H
      17                 :            : #define QGSVECTORTILERENDERER_H
      18                 :            : 
      19                 :            : #include "qgis_core.h"
      20                 :            : 
      21                 :            : #include "qgsfeature.h"
      22                 :            : 
      23                 :            : #include "qgstiles.h"
      24                 :            : 
      25                 :            : class QgsRenderContext;
      26                 :            : 
      27                 :            : //! Features of a vector tile, grouped by sub-layer names (key of the map)
      28                 :            : typedef QMap<QString, QVector<QgsFeature> > QgsVectorTileFeatures SIP_SKIP;
      29                 :            : 
      30                 :            : /**
      31                 :            :  * \ingroup core
      32                 :            :  * \brief Contains decoded features of a single vector tile and any other data necessary
      33                 :            :  * for rendering of it.
      34                 :            :  *
      35                 :            :  * \since QGIS 3.14
      36                 :            :  */
      37                 :          0 : class CORE_EXPORT QgsVectorTileRendererData
      38                 :            : {
      39                 :            :   public:
      40                 :            :     //! Constructs the object
      41                 :          0 :     explicit QgsVectorTileRendererData( QgsTileXYZ id ): mId( id ) {}
      42                 :            : 
      43                 :            :     //! Returns coordinates of the tile
      44                 :          0 :     QgsTileXYZ id() const { return mId; }
      45                 :            : 
      46                 :            :     //! Sets polygon of the tile
      47                 :          0 :     void setTilePolygon( QPolygon polygon ) { mTilePolygon = polygon; }
      48                 :            :     //! Returns polygon (made out of four corners of the tile) in screen coordinates calculated from render context
      49                 :          0 :     QPolygon tilePolygon() const { return mTilePolygon; }
      50                 :            : 
      51                 :            :     //! Sets per-layer fields
      52                 :          0 :     void setFields( const QMap<QString, QgsFields> &fields ) { mFields = fields; }
      53                 :            :     //! Returns per-layer fields
      54                 :          0 :     QMap<QString, QgsFields> fields() const { return mFields; }
      55                 :            : 
      56                 :            :     //! Sets features of the tile
      57                 :          0 :     void setFeatures( const QgsVectorTileFeatures &features ) SIP_SKIP { mFeatures = features; }
      58                 :            :     //! Returns features of the tile grouped by sub-layer names
      59                 :          0 :     QgsVectorTileFeatures features() const SIP_SKIP { return mFeatures; }
      60                 :            :     //! Returns list of layer names present in the tile
      61                 :            :     QStringList layers() const { return mFeatures.keys(); }
      62                 :            :     //! Returns list of all features within a single sub-layer
      63                 :            :     QVector<QgsFeature> layerFeatures( const QString &layerName ) const { return mFeatures[layerName]; }
      64                 :            : 
      65                 :            :   private:
      66                 :            :     //! Position of the tile in the tile matrix set
      67                 :            :     QgsTileXYZ mId;
      68                 :            :     //! Per-layer fields
      69                 :            :     QMap<QString, QgsFields> mFields;
      70                 :            :     //! Features of the tile grouped into sub-layers
      71                 :            :     QgsVectorTileFeatures mFeatures;
      72                 :            :     //! Polygon (made out of four corners of the tile) in screen coordinates calculated from render context
      73                 :            :     QPolygon mTilePolygon;
      74                 :            : };
      75                 :            : 
      76                 :            : /**
      77                 :            :  * \ingroup core
      78                 :            :  * \brief Abstract base class for all vector tile renderer implementations.
      79                 :            :  *
      80                 :            :  * For rendering it is expected that client code calls:
      81                 :            :  *
      82                 :            :  * # startRender() to prepare renderer
      83                 :            :  * # renderTile() for each tile
      84                 :            :  * # stopRender() to clean up renderer and free resources
      85                 :            :  *
      86                 :            :  * \since QGIS 3.14
      87                 :            :  */
      88                 :          0 : class CORE_EXPORT QgsVectorTileRenderer
      89                 :            : {
      90                 :            : 
      91                 :            : #ifdef SIP_RUN
      92                 :            :     SIP_CONVERT_TO_SUBCLASS_CODE
      93                 :            : 
      94                 :            :     const QString type = sipCpp->type();
      95                 :            : 
      96                 :            :     if ( type == QLatin1String( "basic" ) )
      97                 :            :       sipType = sipType_QgsVectorTileBasicRenderer;
      98                 :            :     else
      99                 :            :       sipType = 0;
     100                 :            :     SIP_END
     101                 :            : #endif
     102                 :            : 
     103                 :            :   public:
     104                 :          0 :     virtual ~QgsVectorTileRenderer() = default;
     105                 :            : 
     106                 :            :     //! Returns unique type name of the renderer implementation
     107                 :            :     virtual QString type() const = 0;
     108                 :            : 
     109                 :            :     //! Returns a clone of the renderer
     110                 :            :     virtual QgsVectorTileRenderer *clone() const = 0 SIP_FACTORY;
     111                 :            : 
     112                 :            :     //! Initializes rendering. It should be paired with a stopRender() call.
     113                 :            :     virtual void startRender( QgsRenderContext &context, int tileZoom, const QgsTileRange &tileRange ) = 0;
     114                 :            : 
     115                 :            :     //! Returns field names of sub-layers that will be used for rendering. Must be called between startRender/stopRender.
     116                 :          0 :     virtual QMap<QString, QSet<QString> > usedAttributes( const QgsRenderContext & ) SIP_SKIP { return QMap<QString, QSet<QString> >(); }
     117                 :            : 
     118                 :            :     //TODO QGIS 4.0 -- make pure virtual
     119                 :            : 
     120                 :            :     /**
     121                 :            :      * Returns a list of the layers required for rendering.
     122                 :            :      *
     123                 :            :      * Only layers which are visible at the specified \a tileZoom should be included in this list.
     124                 :            :      *
     125                 :            :      * An empty string present in the list indicates that all layer in the tiles are required.
     126                 :            :      *
     127                 :            :      * \since QGIS 3.16
     128                 :            :      */
     129                 :          0 :     virtual QSet< QString > requiredLayers( QgsRenderContext &context, int tileZoom ) const { Q_UNUSED( context ); Q_UNUSED( tileZoom ); return QSet< QString >() << QString(); }
     130                 :            : 
     131                 :            :     //! Finishes rendering and cleans up any resources
     132                 :            :     virtual void stopRender( QgsRenderContext &context ) = 0;
     133                 :            : 
     134                 :            :     //! Renders given vector tile. Must be called between startRender/stopRender.
     135                 :            :     virtual void renderTile( const QgsVectorTileRendererData &tile, QgsRenderContext &context ) = 0;
     136                 :            : 
     137                 :            :     //! Writes renderer's properties to given XML element
     138                 :            :     virtual void writeXml( QDomElement &elem, const QgsReadWriteContext &context ) const = 0;
     139                 :            :     //! Reads renderer's properties from given XML element
     140                 :            :     virtual void readXml( const QDomElement &elem, const QgsReadWriteContext &context ) = 0;
     141                 :            :     //! Resolves references to other objects - second phase of loading - after readXml()
     142                 :          0 :     virtual void resolveReferences( const QgsProject &project ) { Q_UNUSED( project ) }
     143                 :            : 
     144                 :            : };
     145                 :            : 
     146                 :            : #endif // QGSVECTORTILERENDERER_H