qgsline3dsymbol_p.cpp

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/***************************************************************************
  qgsline3dsymbol_p.cpp
  --------------------------------------
  Date                 : July 2017
  Copyright            : (C) 2017 by Martin Dobias
  Email                : wonder 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 "qgsline3dsymbol_p.h"
 
#include "qgs3d.h"
#include "qgs3dutils.h"
#include "qgsfeature3dhandler_p.h"
#include "qgsgeos.h"
#include "qgsgeotransform.h"
#include "qgshighlightsrenderview.h"
#include "qgsline3dsymbol.h"
#include "qgslinematerial_p.h"
#include "qgslinevertexdata_p.h"
#include "qgsmaterial3dhandler.h"
#include "qgsmessagelog.h"
#include "qgsmultilinestring.h"
#include "qgsmultipolygon.h"
#include "qgsphongtexturedmaterialsettings.h"
#include "qgspolygon.h"
#include "qgssimplelinematerialsettings.h"
#include "qgstessellatedpolygongeometry.h"
#include "qgstessellator.h"
#include "qgsvectorlayer.h"
 
#include <QString>
#include <Qt3DCore/QAttribute>
#include <Qt3DCore/QBuffer>
#include <Qt3DCore/QTransform>
#include <Qt3DRender/QGeometryRenderer>
 
using namespace Qt::StringLiterals;

 
// -----------
 
 
class QgsBufferedLine3DSymbolHandler : public QgsFeature3DHandler
{
  public:
    QgsBufferedLine3DSymbolHandler( const QgsLine3DSymbol *symbol, const QgsFeatureIds &selectedIds )
      : mSymbol( static_cast<QgsLine3DSymbol *>( symbol->clone() ) )
      , mSelectedIds( selectedIds )
    {}
 
    bool prepare( const Qgs3DRenderContext &context, QSet<QString> &attributeNames, const QgsBox3D &chunkExtent ) override;
    void processFeature( const QgsFeature &feature, const Qgs3DRenderContext &context ) override;
    void finalize( Qt3DCore::QEntity *parent, const Qgs3DRenderContext &context ) override;
 
  private:
    struct LineData
    {
        std::unique_ptr<QgsTessellator> tessellator;
        QVector<QgsFeatureId> triangleIndexFids;
        QVector<uint> triangleIndexStartingIndices;
    };
 
    void processPolygon( QgsPolygon *polyBuffered, QgsFeatureId fid, float height, float extrusionHeight, const Qgs3DRenderContext &context, LineData &lineData );
 
    void makeEntity( Qt3DCore::QEntity *parent, const Qgs3DRenderContext &context, LineData &lineData, bool selected );
 
    // input specific for this class
    std::unique_ptr<QgsLine3DSymbol> mSymbol;
    // inputs - generic
    QgsFeatureIds mSelectedIds;
    // outputs
    LineData mLineDataNormal;   
    LineData mLineDataSelected; 
};
 
 
bool QgsBufferedLine3DSymbolHandler::prepare( const Qgs3DRenderContext &, QSet<QString> &attributeNames, const QgsBox3D &chunkExtent )
{
  Q_UNUSED( attributeNames )
 
  mChunkOrigin = chunkExtent.center();
  mChunkOrigin.setZ( 0. ); // set the chunk origin to the bottom of the box, as the tessellator currently always considers origin z to be zero
  mChunkExtent = chunkExtent;
 
  const bool requiresTextureCoordinates = mSymbol->materialSettings() && mSymbol->materialSettings()->requiresTextureCoordinates();
  const bool requiresTangents = mSymbol->materialSettings() && mSymbol->materialSettings()->requiresTangents();
 
  auto lineDataNormalTessellator = std::make_unique<QgsTessellator>();
  lineDataNormalTessellator->setOrigin( mChunkOrigin );
  lineDataNormalTessellator->setAddNormals( true );
  lineDataNormalTessellator->setAddTextureUVs( requiresTextureCoordinates );
  lineDataNormalTessellator->setAddTangents( requiresTangents );
  lineDataNormalTessellator->setExtrusionFaces( Qgis::ExtrusionFace::Walls | Qgis::ExtrusionFace::Roof );
  lineDataNormalTessellator->setTriangulationAlgorithm( Qgis::TriangulationAlgorithm::Earcut );
 
  mLineDataNormal.tessellator = std::move( lineDataNormalTessellator );
 
  auto lineDataSelectedTessellator = std::make_unique<QgsTessellator>();
  lineDataSelectedTessellator->setOrigin( mChunkOrigin );
  lineDataSelectedTessellator->setAddNormals( true );
  lineDataSelectedTessellator->setAddTextureUVs( requiresTextureCoordinates );
  lineDataSelectedTessellator->setAddTangents( requiresTangents );
  lineDataSelectedTessellator->setExtrusionFaces( Qgis::ExtrusionFace::Walls | Qgis::ExtrusionFace::Roof );
  lineDataSelectedTessellator->setTriangulationAlgorithm( Qgis::TriangulationAlgorithm::Earcut );
 
  mLineDataSelected.tessellator = std::move( lineDataSelectedTessellator );
 
  return true;
}
 
void QgsBufferedLine3DSymbolHandler::processFeature( const QgsFeature &feature, const Qgs3DRenderContext &context )
{
  if ( feature.geometry().isNull() )
    return;
 
  LineData &lineData = mSelectedIds.contains( feature.id() ) ? mLineDataSelected : mLineDataNormal;
 
  QgsGeometry geom = feature.geometry();
  clipGeometryIfTooLarge( geom );
 
  if ( geom.isEmpty() )
    return;
 
  const QgsAbstractGeometry *abstractGeom = geom.constGet()->simplifiedTypeRef();
 
  // segmentize curved geometries if necessary
  if ( QgsWkbTypes::isCurvedType( abstractGeom->wkbType() ) )
  {
    geom = QgsGeometry( abstractGeom->segmentize() );
    abstractGeom = geom.constGet()->simplifiedTypeRef();
  }
 
  // TODO: configurable
  const int nSegments = 4;
  const Qgis::EndCapStyle endCapStyle = Qgis::EndCapStyle::Round;
  const Qgis::JoinStyle joinStyle = Qgis::JoinStyle::Round;
  const double mitreLimit = 0;
 
  const QgsGeos engine( abstractGeom );
 
  double width = mSymbol->width();
  if ( qgsDoubleNear( width, 0 ) )
  {
    // a zero-width buffered line should be treated like a "wall" or "fence" -- we fake this by bumping the width to a very tiny amount,
    // so that we get a very narrow polygon shape to work with...
    width = 0.001;
  }
 
  QgsAbstractGeometry *buffered = engine.buffer( width / 2., nSegments, endCapStyle, joinStyle, mitreLimit ); // factory
  if ( !buffered )
    return;
 
  if ( QgsWkbTypes::flatType( buffered->wkbType() ) == Qgis::WkbType::Polygon )
  {
    QgsPolygon *polyBuffered = qgsgeometry_cast<QgsPolygon *>( buffered );
    processPolygon( polyBuffered, feature.id(), mSymbol->offset(), mSymbol->extrusionHeight(), context, lineData );
  }
  else if ( QgsWkbTypes::flatType( buffered->wkbType() ) == Qgis::WkbType::MultiPolygon )
  {
    QgsMultiPolygon *mpolyBuffered = qgsgeometry_cast<QgsMultiPolygon *>( buffered );
    for ( int i = 0; i < mpolyBuffered->numGeometries(); ++i )
    {
      QgsPolygon *polyBuffered = qgsgeometry_cast<QgsPolygon *>( mpolyBuffered->polygonN( i ) )->clone(); // need to clone individual geometry parts
      processPolygon( polyBuffered, feature.id(), mSymbol->offset(), mSymbol->extrusionHeight(), context, lineData );
    }
    delete buffered;
  }
  mFeatureCount++;
}
 
void QgsBufferedLine3DSymbolHandler::processPolygon( QgsPolygon *polyBuffered, QgsFeatureId fid, float height, float extrusionHeight, const Qgs3DRenderContext &context, LineData &lineData )
{
  Qgs3DUtils::clampAltitudes( polyBuffered, mSymbol->altitudeClamping(), mSymbol->altitudeBinding(), height, context );
 
  Q_ASSERT( lineData.tessellator->dataVerticesCount() % 3 == 0 );
  const uint startingTriangleIndex = static_cast<uint>( lineData.tessellator->dataVerticesCount() / 3 );
  lineData.triangleIndexStartingIndices.append( startingTriangleIndex );
  lineData.triangleIndexFids.append( fid );
  lineData.tessellator->addPolygon( *polyBuffered, extrusionHeight );
  if ( !lineData.tessellator->error().isEmpty() )
  {
    QgsMessageLog::logMessage( lineData.tessellator->error(), QObject::tr( "3D" ) );
  }
 
  delete polyBuffered;
}
 
void QgsBufferedLine3DSymbolHandler::finalize( Qt3DCore::QEntity *parent, const Qgs3DRenderContext &context )
{
  // create entity for selected and not selected
  makeEntity( parent, context, mLineDataNormal, false );
  makeEntity( parent, context, mLineDataSelected, true );
 
  mZMin = std::min( mLineDataNormal.tessellator->zMinimum(), mLineDataSelected.tessellator->zMinimum() );
  mZMax = std::max( mLineDataNormal.tessellator->zMaximum(), mLineDataSelected.tessellator->zMaximum() );
}
 
 
void QgsBufferedLine3DSymbolHandler::makeEntity( Qt3DCore::QEntity *parent, const Qgs3DRenderContext &context, LineData &lineData, bool selected )
{
  if ( lineData.tessellator->dataVerticesCount() == 0 )
    return; // nothing to show - no need to create the entity
 
  QgsMaterialContext materialContext = QgsMaterialContext::fromRenderContext( context );
  materialContext.setIsSelected( selected );
  materialContext.setIsHighlighted( mHighlightingEnabled );
 
  QgsMaterial *material = Qgs3D::toMaterial( mSymbol->materialSettings(), Qgis::MaterialRenderingTechnique::Triangles, materialContext );
 
  // extract vertex buffer data from tessellator
  const QByteArray vertexBuffer = lineData.tessellator->vertexBuffer();
  const QByteArray indexBuffer = lineData.tessellator->indexBuffer();
  const int vertexCount = vertexBuffer.count() / lineData.tessellator->stride();
  const size_t indexCount = lineData.tessellator->dataVerticesCount();
 
  QgsTessellatedPolygonGeometry *geometry = new QgsTessellatedPolygonGeometry(
    true, false, false, mSymbol->materialSettings() && mSymbol->materialSettings()->requiresTextureCoordinates(), mSymbol->materialSettings() && mSymbol->materialSettings()->requiresTangents()
  );
  geometry->setVertexBufferData( vertexBuffer, vertexCount, lineData.triangleIndexFids, lineData.triangleIndexStartingIndices );
  geometry->setIndexBufferData( indexBuffer, indexCount );
 
  Qt3DRender::QGeometryRenderer *renderer = new Qt3DRender::QGeometryRenderer;
  renderer->setGeometry( geometry );
 
  // add transform (our geometry has coordinates relative to mChunkOrigin)
  QgsGeoTransform *transform = new QgsGeoTransform;
  transform->setGeoTranslation( mChunkOrigin );
 
  // make entity
  Qt3DCore::QEntity *entity = new Qt3DCore::QEntity;
  entity->addComponent( renderer );
  entity->addComponent( material );
  entity->addComponent( transform );
  entity->setParent( parent );
 
  if ( !selected )
    renderer->setProperty( Qgs3DTypes::PROP_NAME_3D_RENDERER_FLAG, Qgs3DTypes::Main3DRenderer ); // temporary measure to distinguish between "selected" and "main"
 
  // cppcheck wrongly believes entity will leak
  // cppcheck-suppress memleak
}
 
 
// --------------
 
 
class QgsThickLine3DSymbolHandler : public QgsFeature3DHandler
{
  public:
    QgsThickLine3DSymbolHandler( const QgsLine3DSymbol *symbol, const QgsFeatureIds &selectedIds )
      : mSymbol( static_cast<QgsLine3DSymbol *>( symbol->clone() ) )
      , mSelectedIds( selectedIds )
    {}
 
    bool prepare( const Qgs3DRenderContext &context, QSet<QString> &attributeNames, const QgsBox3D &chunkExtent ) override;
    void processFeature( const QgsFeature &feature, const Qgs3DRenderContext &context ) override;
    void finalize( Qt3DCore::QEntity *parent, const Qgs3DRenderContext &context ) override;
 
  private:
    void makeEntity( Qt3DCore::QEntity *parent, const Qgs3DRenderContext &context, QgsLineVertexData &lineVertexData, bool selected );
    void processMaterialDatadefined( uint count, const QgsExpressionContext &context, QByteArray &target );
 
    // input specific for this class
    std::unique_ptr<QgsLine3DSymbol> mSymbol;
    // inputs - generic
    QgsFeatureIds mSelectedIds;
    // outputs
    QgsLineVertexData mLineDataNormal;   
    QgsLineVertexData mLineDataSelected; 
};
 
 
bool QgsThickLine3DSymbolHandler::prepare( const Qgs3DRenderContext &context, QSet<QString> &attributeNames, const QgsBox3D &chunkExtent )
{
  Q_UNUSED( attributeNames )
 
  mChunkOrigin = chunkExtent.center();
  mChunkExtent = chunkExtent;
 
  mLineDataNormal.init( mSymbol->altitudeClamping(), mSymbol->altitudeBinding(), mSymbol->offset(), context, mChunkOrigin );
  mLineDataSelected.init( mSymbol->altitudeClamping(), mSymbol->altitudeBinding(), mSymbol->offset(), context, mChunkOrigin );
 
  QSet<QString> attrs = mSymbol->dataDefinedProperties().referencedFields( context.expressionContext() );
  attributeNames.unite( attrs );
  attrs = mSymbol->materialSettings()->dataDefinedProperties().referencedFields( context.expressionContext() );
  attributeNames.unite( attrs );
 
  return true;
}
 
void QgsThickLine3DSymbolHandler::processFeature( const QgsFeature &feature, const Qgs3DRenderContext &context )
{
  if ( feature.geometry().isNull() )
    return;
 
  QgsLineVertexData &lineVertexData = mSelectedIds.contains( feature.id() ) ? mLineDataSelected : mLineDataNormal;
 
  const int oldSegmentCount = lineVertexData.pointsA.size();
  const int oldJoinCount = lineVertexData.joinPointA.size();
 
  QgsGeometry geom = feature.geometry();
  ( void ) clipGeometryIfTooLarge( geom );
 
  if ( geom.isEmpty() )
    return;
 
  const QgsAbstractGeometry *abstractGeom = geom.constGet()->simplifiedTypeRef();
 
  // segmentize curved geometries if necessary
  if ( QgsWkbTypes::isCurvedType( abstractGeom->wkbType() ) )
  {
    geom = QgsGeometry( abstractGeom->segmentize() );
    abstractGeom = geom.constGet()->simplifiedTypeRef();
  }
 
  if ( const QgsLineString *lineString = qgsgeometry_cast<const QgsLineString *>( abstractGeom ) )
  {
    lineVertexData.addLineString( *lineString );
  }
  else if ( const QgsMultiLineString *multiLineString = qgsgeometry_cast<const QgsMultiLineString *>( abstractGeom ) )
  {
    for ( int nGeom = 0; nGeom < multiLineString->numGeometries(); ++nGeom )
    {
      const QgsLineString *lineString = multiLineString->lineStringN( nGeom );
      lineVertexData.addLineString( *lineString );
    }
  }
 
  if ( mSymbol->materialSettings()->dataDefinedProperties().isActive( QgsAbstractMaterialSettings::Property::Ambient ) )
  {
    processMaterialDatadefined( lineVertexData.pointsA.size() - oldSegmentCount, context.expressionContext(), lineVertexData.materialDataDefined );
    processMaterialDatadefined( lineVertexData.joinPointA.size() - oldJoinCount, context.expressionContext(), lineVertexData.materialDataDefinedJoins );
  }
 
  mFeatureCount++;
}
 
void QgsThickLine3DSymbolHandler::finalize( Qt3DCore::QEntity *parent, const Qgs3DRenderContext &context )
{
  // create entity for selected and not selected
  makeEntity( parent, context, mLineDataNormal, false );
  makeEntity( parent, context, mLineDataSelected, true );
 
  updateZRangeFromPositions( mLineDataNormal.vertices );
  updateZRangeFromPositions( mLineDataSelected.vertices );
}
 
 
void QgsThickLine3DSymbolHandler::makeEntity( Qt3DCore::QEntity *parent, const Qgs3DRenderContext &context, QgsLineVertexData &lineVertexData, bool selected )
{
  if ( lineVertexData.pointsA.isEmpty() )
    return;
 
  // material (only ambient color is used for the color)
  QgsMaterialContext materialContext = QgsMaterialContext::fromRenderContext( context );
  materialContext.setIsSelected( selected );
 
  QgsMaterial *material = Qgs3D::toMaterial( mSymbol->materialSettings(), Qgis::MaterialRenderingTechnique::Lines, materialContext );
  if ( !material )
  {
    const QgsSimpleLineMaterialSettings defaultMaterial;
    material = Qgs3D::toMaterial( &defaultMaterial, Qgis::MaterialRenderingTechnique::Lines, materialContext );
  }
 
  QgsLineMaterial *lineMaterial = dynamic_cast<QgsLineMaterial *>( material );
  if ( lineMaterial )
  {
    float width = mSymbol->width();
    if ( mHighlightingEnabled )
    {
      const QgsSettings settings;
      const QColor color = QColor( settings.value( u"Map/highlight/color"_s, Qgis::DEFAULT_HIGHLIGHT_COLOR.name() ).toString() );
      lineMaterial->setLineColor( color );
      // This is a workaround, make lines thicker to avoid rendering thin lines as three parallel lines with a gap between them
      // Ideally we would want highlighted lines to be:
      // - Rendered with an increased line width during highlights render view first pass
      // - Not rendered during highlights render view second pass (multi-viewport one)
      width = std::max<float>( static_cast<float>( QgsHighlightsRenderView::silhouetteWidth() * 2 ), mSymbol->width() );
    }
    lineMaterial->setLineWidth( width );
  }
 
  const bool hasDataDefinedColor = mSymbol->materialSettings()->dataDefinedProperties().isActive( QgsAbstractMaterialSettings::Property::Ambient );
  const QgsAbstractMaterial3DHandler *handler = hasDataDefinedColor ? Qgs3D::handlerForMaterialSettings( mSymbol->materialSettings() ) : nullptr;
 
  Qt3DCore::QEntity *entity = lineVertexData.createSegmentEntity( material, hasDataDefinedColor ? mSymbol->materialSettings() : nullptr, handler );
 
  // add transform (our geometry has coordinates relative to mChunkOrigin)
  QgsGeoTransform *transform = new QgsGeoTransform;
  transform->setGeoTranslation( mChunkOrigin );
 
  entity->addComponent( transform );
  entity->setParent( parent );
 
  if ( lineMaterial )
  {
    if ( Qt3DCore::QEntity *joinEntity = lineVertexData.createJoinEntity( lineMaterial, hasDataDefinedColor ? mSymbol->materialSettings() : nullptr, handler ) )
    {
      QgsGeoTransform *joinTransform = new QgsGeoTransform;
      joinTransform->setGeoTranslation( mChunkOrigin );
      joinEntity->addComponent( joinTransform );
      joinEntity->setParent( parent );
    }
  }
}
 
void QgsThickLine3DSymbolHandler::processMaterialDatadefined( uint count, const QgsExpressionContext &context, QByteArray &target )
{
  QByteArray bytes;
  if ( const QgsAbstractMaterial3DHandler *handler = Qgs3D::handlerForMaterialSettings( mSymbol->materialSettings() ) )
  {
    bytes = handler->dataDefinedVertexColorsAsByte( mSymbol->materialSettings(), context );
  }
  target.append( bytes.repeated( static_cast<int>( count ) ) );
}
 
// --------------
 
 
namespace Qgs3DSymbolImpl
{
 
  QgsFeature3DHandler *handlerForLine3DSymbol( const QgsVectorLayer *layer, const QgsAbstract3DSymbol *symbol )
  {
    const QgsLine3DSymbol *lineSymbol = dynamic_cast<const QgsLine3DSymbol *>( symbol );
    if ( !lineSymbol )
      return nullptr;
 
    if ( lineSymbol->renderAsSimpleLines() )
      return new QgsThickLine3DSymbolHandler( lineSymbol, layer->selectedFeatureIds() );
    else
      return new QgsBufferedLine3DSymbolHandler( lineSymbol, layer->selectedFeatureIds() );
  }
} // namespace Qgs3DSymbolImpl