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       1                 :            : /***************************************************************************
       2                 :            :   qgsvectortilemvtencoder.h
       3                 :            :   --------------------------------------
       4                 :            :   Date                 : April 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 QGSVECTORTILEMVTENCODER_H
      17                 :            : #define QGSVECTORTILEMVTENCODER_H
      18                 :            : 
      19                 :            : #define SIP_NO_FILE
      20                 :            : 
      21                 :            : #include "qgstiles.h"
      22                 :            : #include "qgsvectortilerenderer.h"
      23                 :            : #include "vector_tile.pb.h"
      24                 :            : 
      25                 :            : 
      26                 :            : /**
      27                 :            :  * \ingroup core
      28                 :            :  * \brief Handles conversion of vector features to Mapbox vector tiles encoding.
      29                 :            :  *
      30                 :            :  * Geometries are stored as a series of MoveTo / LineTo / ClosePath commands
      31                 :            :  * with coordinates in integer values (see resolution(), called "extent" in the spec).
      32                 :            :  * Attributes are stored as key-value pairs of tags: keys are always strings, values
      33                 :            :  * can be integers, floating point numbers, booleans or strings.
      34                 :            :  *
      35                 :            :  * See the specification for details:
      36                 :            :  * https://github.com/mapbox/vector-tile-spec/blob/master/2.1/README.md
      37                 :            :  *
      38                 :            :  * \since QGIS 3.14
      39                 :            :  */
      40                 :          0 : class CORE_EXPORT QgsVectorTileMVTEncoder
      41                 :            : {
      42                 :            :   public:
      43                 :            :     //! Creates MVT encoder for the given tile coordinates
      44                 :            :     explicit QgsVectorTileMVTEncoder( QgsTileXYZ tileID );
      45                 :            : 
      46                 :            :     //! Returns resolution of coordinates of geometries within the tile. The default is 4096.
      47                 :            :     int resolution() const { return mResolution; }
      48                 :            :     //! Sets the resolution of coordinates of geometries within the tile
      49                 :            :     void setResolution( int extent ) { mResolution = extent; }
      50                 :            : 
      51                 :            :     //! Returns size of the buffer zone around tile edges in integer tile coordinates. The default is 256 (~6%)
      52                 :            :     int tileBuffer() const { return mBuffer; }
      53                 :            :     //! Sets size of the buffer zone around tile edges in integer tile coordinates
      54                 :            :     void setTileBuffer( int buffer ) { mBuffer = buffer; }
      55                 :            : 
      56                 :            :     //! Sets coordinate transform context for transforms between layers and tile matrix CRS
      57                 :          0 :     void setTransformContext( const QgsCoordinateTransformContext &transformContext ) { mTransformContext = transformContext; }
      58                 :            : 
      59                 :            :     /**
      60                 :            :      * Fetches data from vector layer for the given tile, does reprojection and clipping
      61                 :            :      *
      62                 :            :      * Optional feedback object may be provided to support cancellation.
      63                 :            :      */
      64                 :            :     void addLayer( QgsVectorLayer *layer, QgsFeedback *feedback = nullptr, QString filterExpression = QString(), QString layerName = QString() );
      65                 :            : 
      66                 :            :     //! Encodes MVT using data stored previously with addLayer() calls
      67                 :            :     QByteArray encode() const;
      68                 :            : 
      69                 :            :   private:
      70                 :            :     void addFeature( vector_tile::Tile_Layer *tileLayer, const QgsFeature &f );
      71                 :            : 
      72                 :            :   private:
      73                 :            :     QgsTileXYZ mTileID;
      74                 :            :     int mResolution = 4096;
      75                 :            :     int mBuffer = 256;
      76                 :            :     QgsCoordinateTransformContext mTransformContext;
      77                 :            : 
      78                 :            :     QgsRectangle mTileExtent;
      79                 :            : 
      80                 :            :     QgsVectorTileFeatures mFeatures;
      81                 :            : 
      82                 :            :     vector_tile::Tile tile;
      83                 :            : 
      84                 :            :     QMap<QVariant, int> mKnownValues;
      85                 :            : 
      86                 :            : };
      87                 :            : 
      88                 :            : #endif // QGSVECTORTILEMVTENCODER_H