qgscategorizedchunkloader_p.h

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/***************************************************************************
  qgscategorizedchunkloader_p.h
  --------------------------------------
  Date                 : November 2025
  Copyright            : (C) 2025 by Jean Felder
  Email                : jean dot felder at oslandia dot com
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#ifndef QGSCATEGORIZEDCHUNKLOADER_H
#define QGSCATEGORIZEDCHUNKLOADER_H

 
//
//  W A R N I N G
//  -------------
//
// This file is not part of the QGIS API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
 
#include "qgs3drendercontext.h"
#include "qgsabstractfeaturebasedchunkedentity.h"
#include "qgscategorized3drenderer.h"
#include "qgschunkloader.h"
 
#include <QFutureWatcher>
#include <QMutex>
 
#define SIP_NO_FILE
 
class Qgs3DMapSettings;
class QgsVectorLayer;
class QgsVectorLayerFeatureSource;
class QgsAbstract3DSymbol;
class QgsFeature3DHandler;
 
namespace Qt3DCore
{
  class QTransform;
}

class QgsCategorizedChunkLoader : public QgsQuadtreeChunkLoader
{
    Q_OBJECT
 
  public:
    QgsCategorizedChunkLoader( const Qgs3DRenderContext &context, QgsVectorLayer *vectorLayer, const QgsCategorized3DRenderer *renderer, double zMin, double zMax, int maxFeatures );
    ~QgsCategorizedChunkLoader() override;
 
    QFuture<QgsChunkLoaderResult> loadChunk( QgsChunkNode *node ) override;
    QFuture<QVector<QgsChunkNode *>> createChildren( QgsChunkNode *node ) override;
 
  private:
    struct NodeIsLeafMap
    {
        QHash< QString, bool > map;
        QMutex mutex;
    };

    struct ChunkLoadingContext
    {
        // We need shared_ptr, because we capture this in std::function. We could
        // get around this with std::move_only_function (C++23 feature) or by
        // returning a custom allocated object with virtual methods.
        QgsChunkNode *node;
        std::shared_ptr<QgsVectorLayerFeatureSource> source;
        Qgs3DRenderContext renderCtx;
        std::vector<std::shared_ptr<QgsFeature3DHandler>> handlers;
        QHash<QString, QgsFeature3DHandler *> featuresHandlerHash;
        std::shared_ptr<QgsExpression> expression;
        int attributeIdx = -1;
        int maxFeatures;
        std::shared_ptr<NodeIsLeafMap> nodesAreLeafs;
    };
 
    static void loadChunkInWorker( QPromise<ChunkLoadingContext> &promise, ChunkLoadingContext ctx, QgsFeatureRequest request );
    Qt3DCore::QEntity *createEntity( ChunkLoadingContext ctx, Qt3DCore::QEntity *parent );
    static void processFeature( ChunkLoadingContext &ctx, const QgsFeature &feature );
 
    Qgs3DRenderContext mRenderContext;
    const QgsVectorLayer *mLayer = nullptr;
    const Qgs3DCategoryList *mCategories = nullptr;
    QString mAttributeName;
    std::shared_ptr<NodeIsLeafMap> mNodesAreLeafs;
    int mMaxFeatures = 0;
 
    friend class QgsCategorizedChunkedEntity;
};

class QgsCategorizedChunkedEntity : public QgsAbstractFeatureBasedChunkedEntity
{
    Q_OBJECT
  public:
    explicit QgsCategorizedChunkedEntity(
      Qgs3DMapSettings *mapSettings, QgsVectorLayer *vectorLayer, double zMin, double zMax, const QgsVectorLayer3DTilingSettings &tilingSettings, const QgsCategorized3DRenderer *renderer
    );
 
    ~QgsCategorizedChunkedEntity() override;
 
  private:
    bool applyTerrainOffset() const override;
};

 
#endif // QGSCATEGORIZEDCHUNKLOADER_H