qgspointcloudlayerchunkloader_p.cpp

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/***************************************************************************
  qgspointcloudlayerchunkloader_p.cpp
  --------------------------------------
  Date                 : October 2020
  Copyright            : (C) 2020 by Peter Petrik
  Email                : zilolv dot sk at gmail 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.                                   *
 *                                                                         *
 ***************************************************************************/
 
#include "qgspointcloudlayerchunkloader_p.h"
 
#include <memory>
 
#include "qgs3dutils.h"
#include "qgsbox3d.h"
#include "qgschunkloader.h"
#include "qgschunknode.h"
#include "qgseventtracing.h"
#include "qgslogger.h"
#include "qgspointcloud3dsymbol.h"
#include "qgspointcloud3dsymbol_p.h"
#include "qgspointcloudattribute.h"
#include "qgspointcloudindex.h"
#include "qgspointcloudlayer.h"
#include "qgspointcloudlayer3drenderer.h"
#include "qgspointcloudrequest.h"
#include "qgsray3d.h"
#include "qgsraycastcontext.h"
#include "qgsraycastingutils.h"
#include "qgsthreadingutils.h"
 
#include <QPointSize>
#include <QString>
#include <Qt3DCore/QAttribute>
#include <Qt3DRender/QGraphicsApiFilter>
#include <Qt3DRender/QShaderProgram>
#include <Qt3DRender/QTechnique>
#include <QtConcurrentRun>
 
#include "moc_qgspointcloudlayerchunkloader_p.cpp"
 
using namespace Qt::StringLiterals;

 
QgsPointCloudLayerChunkLoader::QgsPointCloudLayerChunkLoader(
  const Qgs3DRenderContext &context, const QgsCoordinateTransform &coordinateTransform, QgsPointCloudIndex pc, QgsPointCloud3DSymbol *symbol, double zValueScale, double zValueOffset, int pointBudget
)
  : mRenderContext( context )
  , mCoordinateTransform( coordinateTransform )
  , mPointCloudIndex( std::move( pc ) )
  , mZValueScale( zValueScale )
  , mZValueOffset( zValueOffset )
  , mPointBudget( pointBudget )
{
  mSymbol.reset( symbol );
 
  if ( context.crs().type() != Qgis::CrsType::Geocentric ) // extent is not used for globe
  {
    try
    {
      mExtent = mCoordinateTransform.transformBoundingBox( mRenderContext.extent(), Qgis::TransformDirection::Reverse );
    }
    catch ( const QgsCsException & )
    {
      // bad luck, can't reproject for some reason
      QgsDebugError( u"Transformation of extent failed."_s );
    }
  }
}
 
QFuture<QgsChunkLoaderResult> QgsPointCloudLayerChunkLoader::loadChunk( QgsChunkNode *node )
{
  const QgsChunkNodeId id = node->tileId();
 
  Q_ASSERT( mPointCloudIndex.hasNode( QgsPointCloudNodeId( id.d, id.x, id.y, id.z ) ) );
  QgsPointCloud3DSymbol *symbol = static_cast<QgsPointCloud3DSymbol *>( mSymbol->clone() );
 
  // Wrapped in shared_ptr to allow copying
  auto context = std::make_shared<QgsPointCloud3DRenderContext>( mRenderContext, mCoordinateTransform, std::unique_ptr<QgsPointCloud3DSymbol>( symbol ), mZValueScale, mZValueOffset );
 
  QgsPointCloudIndex pc = mPointCloudIndex;
  context->setAttributes( pc.attributes() );
 
  const QgsChunkNodeId nodeId = node->tileId();
  const QgsPointCloudNodeId pcNode( nodeId.d, nodeId.x, nodeId.y, nodeId.z );
 
  Q_ASSERT( pc.hasNode( pcNode ) );
 
  QgsDebugMsgLevel( u"loading entity %1"_s.arg( node->tileId().text() ), 2 );
 
  std::shared_ptr<QgsPointCloud3DSymbolHandler> handler;
  if ( context->symbol()->symbolType() == "single-color"_L1 )
    handler = std::make_shared<QgsSingleColorPointCloud3DSymbolHandler>();
  else if ( context->symbol()->symbolType() == "color-ramp"_L1 )
    handler = std::make_shared<QgsColorRampPointCloud3DSymbolHandler>();
  else if ( context->symbol()->symbolType() == "rgb"_L1 )
    handler = std::make_shared<QgsRGBPointCloud3DSymbolHandler>();
  else if ( context->symbol()->symbolType() == "classification"_L1 )
  {
    handler = std::make_shared<QgsClassificationPointCloud3DSymbolHandler>();
    const QgsClassificationPointCloud3DSymbol *classificationSymbol = dynamic_cast<const QgsClassificationPointCloud3DSymbol *>( context->symbol() );
    context->setFilteredOutCategories( classificationSymbol->getFilteredOutCategories() );
  }
 
  const QgsBox3D box3D = node->box3D();
  return QtConcurrent::run( [pc = std::move( pc ), node, pcNode, box3D, context, handler]( QPromise<QgsChunkLoaderResult> &promise ) mutable {
    const QgsScopedEvent e( u"3D"_s, u"PC chunk load"_s );
 
    if ( promise.isCanceled() )
    {
      QgsDebugMsgLevel( u"canceled"_s, 2 );
      promise.addResult( QgsChunkLoaderResult::sEmpty );
      return;
    }
 
    handler->processNode( pc, pcNode, *context );
 
    if ( promise.isCanceled() )
    {
      QgsDebugMsgLevel( u"canceled"_s, 2 );
      promise.addResult( QgsChunkLoaderResult::sEmpty );
      return;
    }
 
    if ( context->symbol()->renderAsTriangles() )
      handler->triangulate( pc, pcNode, *context, box3D );
 
    promise.addResult( QgsChunkLoaderResult { [node, handler, context, pc]( Qt3DCore::QEntity *parent ) -> Qt3DCore::QEntity * {
      QGIS_CHECK_MAIN_THREAD_ACCESS
      const QgsChunkNodeId nodeId = node->tileId();
      const QgsPointCloudNodeId pcNode( nodeId.d, nodeId.x, nodeId.y, nodeId.z );
      Q_ASSERT( pc.hasNode( pcNode ) );
 
      Qt3DCore::QEntity *entity = new Qt3DCore::QEntity( parent );
      handler->finalize( entity, *context );
      return entity;
    } } );
  } );
}
 
int QgsPointCloudLayerChunkLoader::primitivesCount( QgsChunkNode *node ) const
{
  const QgsChunkNodeId id = node->tileId();
  const QgsPointCloudNodeId n( id.d, id.x, id.y, id.z );
  Q_ASSERT( mPointCloudIndex.hasNode( n ) );
  return mPointCloudIndex.getNode( n ).pointCount();
}
 
QFuture<void> QgsPointCloudLayerChunkLoader::fetchHierarchyForNode( const QgsPointCloudNodeId &nodeId )
{
  return QtConcurrent::run( [index = mPointCloudIndex, nodeId] {
    // we need to make sure that hierarchy exists for this node, children and grand children,
    // so that createChildren() will not trigger hierarchy fetching
    // hasNode() will trigger fetching the hierarchy for this node and any missing ancestors
    ( void ) index.hasNode( nodeId );
    const QVector<QgsPointCloudNodeId> children = nodeId.childrenNodes();
    for ( const QgsPointCloudNodeId &child : children )
    {
      ( void ) index.hasNode( child );
 
      const QVector<QgsPointCloudNodeId> grandchildren = child.childrenNodes();
      for ( const QgsPointCloudNodeId &grandChild : grandchildren )
      {
        ( void ) index.hasNode( grandChild );
      }
    }
  } );
}
 
 
static QgsBox3D nodeBoundsToBox3D( QgsBox3D nodeBounds, const QgsCoordinateTransform &coordinateTransform, double zValueOffset, double zValueScale )
{
  QgsVector3D extentMin3D( nodeBounds.xMinimum(), nodeBounds.yMinimum(), nodeBounds.zMinimum() * zValueScale + zValueOffset );
  QgsVector3D extentMax3D( nodeBounds.xMaximum(), nodeBounds.yMaximum(), nodeBounds.zMaximum() * zValueScale + zValueOffset );
  QgsCoordinateTransform extentTransform = coordinateTransform;
  extentTransform.setBallparkTransformsAreAppropriate( true );
  try
  {
    extentMin3D = extentTransform.transform( extentMin3D );
    extentMax3D = extentTransform.transform( extentMax3D );
  }
  catch ( QgsCsException & )
  {
    QgsDebugError( u"Error transforming node bounds coordinate"_s );
  }
  return QgsBox3D( extentMin3D.x(), extentMin3D.y(), extentMin3D.z(), extentMax3D.x(), extentMax3D.y(), extentMax3D.z() );
}
 
 
QgsChunkNode *QgsPointCloudLayerChunkLoader::createRootNode() const
{
  const QgsPointCloudNode pcNode = mPointCloudIndex.getNode( mPointCloudIndex.root() );
  const QgsBox3D rootNodeBounds = pcNode.bounds();
  QgsBox3D rootNodeBox3D = nodeBoundsToBox3D( rootNodeBounds, mCoordinateTransform, mZValueOffset, mZValueScale );
 
  const float error = pcNode.error();
  QgsChunkNode *node = new QgsChunkNode( QgsChunkNodeId( 0, 0, 0, 0 ), rootNodeBox3D, error );
  node->setRefinementProcess( mSymbol->renderAsTriangles() ? Qgis::TileRefinementProcess::Replacement : Qgis::TileRefinementProcess::Additive );
  return node;
}
 
QFuture<QVector<QgsChunkNode *>> QgsPointCloudLayerChunkLoader::createChildren( QgsChunkNode *node )
{
  const QgsChunkNodeId id = node->tileId();
  const QgsPointCloudNodeId n( id.d, id.x, id.y, id.z );
  if ( mPointCloudIndex.needsHierarchyFetching( n ) )
    return fetchHierarchyForNode( n ).then( this, [this, node]() { return createChildrenInner( node ); } );
  else
    return QtFuture::makeReadyValueFuture( createChildrenInner( node ) );
}
 
QVector<QgsChunkNode *> QgsPointCloudLayerChunkLoader::createChildrenInner( QgsChunkNode *node )
{
  QVector<QgsChunkNode *> children;
  const QgsChunkNodeId nodeId = node->tileId();
  const float childError = node->error() / 2;
  const QgsPointCloudNodeId pcId( nodeId.d, nodeId.x, nodeId.y, nodeId.z );
 
  const QVector<QgsPointCloudNodeId> childrenPcIds = pcId.childrenNodes();
  for ( const QgsPointCloudNodeId &childPcId : childrenPcIds )
  {
    const QgsChunkNodeId childId( childPcId.d(), childPcId.x(), childPcId.y(), childPcId.z() );
    if ( !mPointCloudIndex.hasNode( childPcId ) )
      continue;
    const QgsPointCloudNode childNode = mPointCloudIndex.getNode( childPcId );
    const QgsBox3D childBounds = childNode.bounds();
    if ( !mExtent.isEmpty() && !childBounds.toRectangle().intersects( mExtent ) )
      continue;
 
    QgsBox3D childBox3D = nodeBoundsToBox3D( childBounds, mCoordinateTransform, mZValueOffset, mZValueScale );
 
    QgsChunkNode *child = new QgsChunkNode( childId, childBox3D, childError, node );
    child->setRefinementProcess( mSymbol->renderAsTriangles() ? Qgis::TileRefinementProcess::Replacement : Qgis::TileRefinementProcess::Additive );
    children << child;
  }
  return children;
}

 
 
static QgsChunkNode *findChunkNodeFromNodeId( QgsChunkNode *rootNode, QgsPointCloudNodeId nodeId )
{
  // find path from the node to the root
  QVector<QgsPointCloudNodeId> parentIds;
  while ( nodeId.d() > 0 )
  {
    parentIds << nodeId;
    nodeId = nodeId.parentNode();
  }
 
  // now descend from the root to the node in the QgsChunkNode hierarchy
  QgsChunkNode *chunk = rootNode;
  while ( !parentIds.empty() )
  {
    QgsPointCloudNodeId p = parentIds.takeLast();
    QgsChunkNodeId childNodeId( p.d(), p.x(), p.y(), p.z() );
 
    if ( !chunk->hasChildrenPopulated() )
      return nullptr;
 
    QgsChunkNode *chunkChild = nullptr;
    QgsChunkNode *const *children = chunk->children();
    for ( int i = 0; i < chunk->childCount(); ++i )
    {
      if ( children[i]->tileId() == childNodeId )
      {
        chunkChild = children[i];
        break;
      }
    }
    Q_ASSERT( chunkChild );
    chunk = chunkChild;
  }
  return chunk;
}
 
 
QgsPointCloudLayerChunkedEntity::QgsPointCloudLayerChunkedEntity(
  Qgs3DMapSettings *map,
  QgsPointCloudLayer *pcl,
  const int indexPosition,
  const QgsCoordinateTransform &coordinateTransform,
  QgsPointCloud3DSymbol *symbol,
  float maximumScreenSpaceError,
  bool showBoundingBoxes,
  double zValueScale,
  double zValueOffset,
  int pointBudget
)
  : QgsChunkedEntity( map, maximumScreenSpaceError, new QgsPointCloudLayerChunkLoader( Qgs3DRenderContext::fromMapSettings( map ), coordinateTransform, resolveIndex( pcl, indexPosition ), symbol, zValueScale, zValueOffset, pointBudget ), true, pointBudget )
  , mLayer( pcl )
  , mIndexPosition( indexPosition )
{
  setShowBoundingBoxes( showBoundingBoxes );
 
  if ( pcl->supportsEditing() )
  {
    // when editing starts or stops, we need to update our index to use the editing index (or not)
    if ( ( pcl->isVpc() && indexPosition >= 0 ) || ( !pcl->isVpc() ) )
    {
      connect( pcl, &QgsPointCloudLayer::editingStarted, this, &QgsPointCloudLayerChunkedEntity::updateIndex );
      connect( pcl, &QgsPointCloudLayer::editingStopped, this, &QgsPointCloudLayerChunkedEntity::updateIndex );
      connect( pcl, &QgsPointCloudLayer::chunkAttributeValuesChanged, this, [this]( QgsPointCloudNodeId n, int indexPosition ) {
        if ( indexPosition != mIndexPosition )
          return;
 
        QgsChunkNode *node = findChunkNodeFromNodeId( mRootNode.get(), n );
        if ( node )
        {
          updateNodes( QList<QgsChunkNode *>() << node );
        }
      } );
    }
  }
}
 
QgsPointCloudLayerChunkedEntity::~QgsPointCloudLayerChunkedEntity()
{
  // cancel / wait for jobs
  cancelActiveJobs();
}
 
QgsPointCloudIndex QgsPointCloudLayerChunkedEntity::resolveIndex( const QgsPointCloudLayer *pcl, int indexPosition )
{
  if ( indexPosition >= 0 && pcl->isVpc() )
    return pcl->subIndexes().at( indexPosition ).index();
  else if ( indexPosition == -1 && !pcl->isVpc() )
    return pcl->index();
  else if ( indexPosition < -1 && pcl->isVpc() )
  {
    const int ovId = -indexPosition - 2;
    return pcl->overviews().at( ovId );
  }
  else
    return QgsPointCloudIndex();
}
 
void QgsPointCloudLayerChunkedEntity::updateIndex()
{
  if ( mLayer->isVpc() )
  {
    if ( mIndexPosition >= 0 )
      static_cast<QgsPointCloudLayerChunkLoader *>( mChunkLoader )->mPointCloudIndex = mLayer->subIndexes().at( mIndexPosition ).index();
  }
  else
    static_cast<QgsPointCloudLayerChunkLoader *>( mChunkLoader )->mPointCloudIndex = mLayer->index();
}
 
QList<QgsRayCastHit> QgsPointCloudLayerChunkedEntity::rayIntersection( const QgsRay3D &ray, const QgsRayCastContext &context ) const
{
  QList<QgsRayCastHit> result;
  QgsPointCloudLayerChunkLoader *loader = static_cast<QgsPointCloudLayerChunkLoader *>( mChunkLoader );
 
  const QgsPointCloud3DSymbol *symbol = loader->mSymbol.get();
  // Symbol can be null in case of no rendering enabled
  if ( !symbol )
    return result;
 
  // transform ray
  const QgsVector3D rayOriginMapCoords = loader->mRenderContext.worldToMapCoordinates( ray.origin() );
  const QgsVector3D pointMapCoords = loader->mRenderContext.worldToMapCoordinates( ray.point( ray.origin().length() ) );
  QgsVector3D rayDirectionMapCoords = pointMapCoords - rayOriginMapCoords;
  rayDirectionMapCoords.normalize();
 
  // We're using the angle as a tolerance, effectively meaning we're fetching points intersecting a cone.
  // This may be revisited to use a cylinder instead, if the balance between near/far points does not scale
  // well with different point sizes, screen sizes and fov values.
  const double limitAngle = context.angleThreshold() * M_PI / 180.;
 
  // adjust ray to elevation properties
  const QgsVector3D adjustedRayOrigin = QgsVector3D( rayOriginMapCoords.x(), rayOriginMapCoords.y(), ( rayOriginMapCoords.z() - loader->mZValueOffset ) / loader->mZValueScale );
  QgsVector3D adjustedRayDirection = QgsVector3D( rayDirectionMapCoords.x(), rayDirectionMapCoords.y(), rayDirectionMapCoords.z() / loader->mZValueScale );
  adjustedRayDirection.normalize();
 
  QgsPointCloudIndex index = loader->mPointCloudIndex;
 
  const QgsPointCloudAttributeCollection attributeCollection = index.attributes();
  QgsPointCloudRequest request;
  request.setAttributes( attributeCollection );
 
  double minDist = -1.;
  const QList<QgsChunkNode *> activeNodes = this->activeNodes();
  for ( QgsChunkNode *node : activeNodes )
  {
    const QgsChunkNodeId id = node->tileId();
    const QgsPointCloudNodeId n( id.d, id.x, id.y, id.z );
 
    if ( !index.hasNode( n ) )
      continue;
 
    const QgsAABB nodeBbox = Qgs3DUtils::mapToWorldExtent( node->box3D(), mMapSettings->origin() );
    if ( !QgsRayCastingUtils::rayBoxIntersection( ray, nodeBbox ) )
      continue;
 
    std::unique_ptr<QgsPointCloudBlock> block( index.nodeData( n, request ) );
    if ( !block )
      continue;
 
    const QgsVector3D blockScale = block->scale();
    const QgsVector3D blockOffset = block->offset();
 
    const char *ptr = block->data();
    const QgsPointCloudAttributeCollection blockAttributes = block->attributes();
    const std::size_t recordSize = blockAttributes.pointRecordSize();
    int xOffset = 0, yOffset = 0, zOffset = 0;
    const QgsPointCloudAttribute::DataType xType = blockAttributes.find( u"X"_s, xOffset )->type();
    const QgsPointCloudAttribute::DataType yType = blockAttributes.find( u"Y"_s, yOffset )->type();
    const QgsPointCloudAttribute::DataType zType = blockAttributes.find( u"Z"_s, zOffset )->type();
    for ( int i = 0; i < block->pointCount(); ++i )
    {
      double x, y, z;
      QgsPointCloudAttribute::getPointXYZ( ptr, i, recordSize, xOffset, xType, yOffset, yType, zOffset, zType, blockScale, blockOffset, x, y, z );
      const QgsVector3D point( x, y, z );
 
      // check whether point is in front of the ray
      // similar to QgsRay3D::isInFront(), but using doubles
      QgsVector3D vectorToPoint = point - adjustedRayOrigin;
      vectorToPoint.normalize();
      if ( QgsVector3D::dotProduct( vectorToPoint, adjustedRayDirection ) < 0.0 )
        continue;
 
      // calculate the angle between the point and the projected point
      // similar to QgsRay3D::angleToPoint(), but using doubles
      const QgsVector3D projPoint = adjustedRayOrigin + adjustedRayDirection * QgsVector3D::dotProduct( point - adjustedRayOrigin, adjustedRayDirection );
 
      const double d1 = projPoint.distance( adjustedRayOrigin );
      const double d2 = projPoint.distance( point );
      const double angle = std::atan2( d2, d1 );
 
      if ( angle > limitAngle )
        continue;
 
      const double dist = rayOriginMapCoords.distance( point );
 
      if ( minDist < 0 || dist < minDist )
      {
        minDist = dist;
      }
      else if ( context.singleResult() )
      {
        continue;
      }
 
      // Note : applying elevation properties is done in fromPointCloudIdentificationToIdentifyResults
      QVariantMap pointAttr = QgsPointCloudAttribute::getAttributeMap( ptr, i * recordSize, blockAttributes );
      pointAttr[u"X"_s] = x;
      pointAttr[u"Y"_s] = y;
      pointAttr[u"Z"_s] = z;
 
      QgsRayCastHit hit;
      hit.setDistance( dist );
      hit.setMapCoordinates( point );
      hit.setProperties( pointAttr );
      if ( context.singleResult() )
        result.clear();
      result.append( hit );
    }
  }
  return result;
}