Greatly simplify and optimise interpolation code, correct handling of

nyalldawson · nyalldawson · commit cb292c18f928 · 2017-11-03T07:42:32.000+10:00
Z/M dimensioned geometries
diff --git a/src/analysis/interpolation/qgsinterpolator.cpp b/src/analysis/interpolation/qgsinterpolator.cpp
@@ -32,7 +32,7 @@ QgsInterpolator::Result QgsInterpolator::cacheBaseData( QgsFeedback *feedback )
 {
   if ( mLayerData.empty() )
   {
-    return 0;
+    return Success;
   }
 
   //reserve initial memory for 100000 vertices
@@ -49,7 +49,7 @@ QgsInterpolator::Result QgsInterpolator::cacheBaseData( QgsFeedback *feedback )
     QgsFeatureSource *source = layer.source;
     if ( !source )
     {
-      return 2;
+      return InvalidSource;
     }
 
     QgsAttributeList attList;
@@ -95,237 +95,26 @@ QgsInterpolator::Result QgsInterpolator::cacheBaseData( QgsFeedback *feedback )
     layerCount++;
   }
 
-  return 0;
+  return Success;
 }
 
-int QgsInterpolator::addVerticesToCache( const QgsGeometry &geom, bool zCoord, double attributeValue )
+bool QgsInterpolator::addVerticesToCache( const QgsGeometry &geom, bool zCoord, double attributeValue )
 {
-  if ( geom.isNull() )
-    return 1;
+  if ( !geom || geom.isEmpty() )
+    return true; // nothing to do
 
-  bool hasZValue = false;
-  QByteArray wkb( geom.exportToWkb() );
-  QgsConstWkbPtr currentWkbPtr( wkb );
-  currentWkbPtr.readHeader();
-  vertexData vertex; //the current vertex
-
-  QgsWkbTypes::Type wkbType = geom.wkbType();
-  switch ( wkbType )
+  bool hasZ = geom.constGet()->is3D();
+  for ( auto point = geom.vertices_begin(); point != geom.vertices_end(); ++point )
   {
-    case QgsWkbTypes::Point25D:
-      hasZValue = true;
-      //intentional fall-through
-      FALLTHROUGH;
-    case QgsWkbTypes::Point:
-    {
-      currentWkbPtr >> vertex.x >> vertex.y;
-      if ( zCoord && hasZValue )
-      {
-        currentWkbPtr >> vertex.z;
-      }
-      else
-      {
-        vertex.z = attributeValue;
-      }
-      mCachedBaseData.push_back( vertex );
-      break;
-    }
-    case QgsWkbTypes::LineString25D:
-      hasZValue = true;
-      //intentional fall-through
-      FALLTHROUGH;
-    case QgsWkbTypes::LineString:
-    {
-      int nPoints;
-      currentWkbPtr >> nPoints;
-      for ( int index = 0; index < nPoints; ++index )
-      {
-        currentWkbPtr >> vertex.x >> vertex.y;
-        if ( zCoord && hasZValue ) //skip z-coordinate for 25D geometries
-        {
-          currentWkbPtr >> vertex.z;
-        }
-        else
-        {
-          vertex.z = attributeValue;
-        }
-        mCachedBaseData.push_back( vertex );
-      }
-      break;
-    }
-#if 0
-    case QgsWkbTypes::Polygon25D:
-      hasZValue = true;
-    //intentional fall-through
-    case QgsWkbTypes::Polygon:
-    {
-      int nRings;
-      wkbPtr >> nRings;
-      for ( int index = 0; index < nRings; ++index )
-      {
-        int nPoints;
-        wkbPtr >> nPoints;
-        for ( int index2 = 0; index2 < *npoints; ++index2 )
-        {
-          double x, y;
-          wkbPtr >> x >> y;
-          if ( point.sqrDist( x, y ) < actdist )
-          {
-            actdist = point.sqrDist( x, y );
-            vertexnr = vertexcounter;
-            //assign the rubber band indices
-            if ( index2 == 0 )
-            {
-              beforeVertex = vertexcounter + ( *npoints - 2 );
-              afterVertex = vertexcounter + 1;
-            }
-            else if ( index2 == ( *npoints - 1 ) )
-            {
-              beforeVertex = vertexcounter - 1;
-              afterVertex = vertexcounter - ( *npoints - 2 );
-            }
-            else
-            {
-              beforeVertex = vertexcounter - 1;
-              afterVertex = vertexcounter + 1;
-            }
-          }
-          if ( hasZValue ) //skip z-coordinate for 25D geometries
-          {
-            wkbPtr += sizeof( double );
-          }
-          ++vertexcounter;
-        }
-      }
-      break;
-    }
-    case QgsWkbTypes::MultiPoint25D:
-      hasZValue = true;
-    //intentional fall-through
-    case QgsWkbTypes::MultiPoint:
-    {
-      int nPoints;
-      wkbPtr >> nPoints;
-      for ( int index = 0; index < nPoints; ++index )
-      {
-        wkbPtr += 1 + sizeof( int ); //skip endian and point type
-
-        double x, y;
-        wkbPtr >> x >> y;
-        if ( point.sqrDist( x, y ) < actdist )
-        {
-          actdist = point.sqrDist( x, y );
-          vertexnr = index;
-        }
-        if ( hasZValue ) //skip z-coordinate for 25D geometries
-        {
-          wkbPtr += sizeof( double );
-        }
-      }
-      break;
-    }
-    case QgsWkbTypes::MultiLineString25D:
-      hasZValue = true;
-    //intentional fall-through
-    case QgsWkbTypes::MultiLineString:
+    if ( hasZ && zCoord )
     {
-      int nLines;
-      wkbPtr >> nLines;
-      for ( int index = 0; index < nLines; ++index )
-      {
-        int nPoints;
-        wkbPtr >> nPoints;
-        for ( int index2 = 0; index2 < nPoints; ++index2 )
-        {
-          double x, y;
-          wkbPtr >> x >> y;
-          if ( point.sqrDist( x, y ) < actdist )
-          {
-            actdist = point.sqrDist( x, y );
-            vertexnr = vertexcounter;
-
-            if ( index2 == 0 )//assign the rubber band indices
-            {
-              beforeVertex = -1;
-            }
-            else
-            {
-              beforeVertex = vertexnr - 1;
-            }
-            if ( index2 == nPoints - 1 )
-            {
-              afterVertex = -1;
-            }
-            else
-            {
-              afterVertex = vertexnr + 1;
-            }
-          }
-          if ( hasZValue ) //skip z-coordinate for 25D geometries
-          {
-            wkbPtr += sizeof( double );
-          }
-          ++vertexcounter;
-        }
-      }
-      break;
+      mCachedBaseData.push_back( QgsInterpolatorVertexData( ( *point ).x(), ( *point ).y(), ( *point ).z() ) );
     }
-    case QgsWkbTypes::MultiPolygon25D:
-      hasZValue = true;
-    //intentional fall-through
-    case QgsWkbTypes::MultiPolygon:
+    else
     {
-      int nPolys;
-      wkbPtr >> nPolys;
-      for ( int index = 0; index < nPolys; ++index )
-      {
-        wkbPtr += 1 + sizeof( int ); //skip endian and polygon type
-        int nRings;
-        wkbPtr >> nRings;
-        for ( int index2 = 0; index2 < nRings; ++index2 )
-        {
-          int nPoints;
-          wkbPtr >> nPoints;
-          for ( int index3 = 0; index3 < nPoints; ++index3 )
-          {
-            double x, y;
-            wkbPtr >> x >> y;
-            if ( point.sqrDist( x, y ) < actdist )
-            {
-              actdist = point.sqrDist( x, y );
-              vertexnr = vertexcounter;
-
-              //assign the rubber band indices
-              if ( index3 == 0 )
-              {
-                beforeVertex = vertexcounter + ( nPoints - 2 );
-                afterVertex = vertexcounter + 1;
-              }
-              else if ( index3 == ( *npoints - 1 ) )
-              {
-                beforeVertex = vertexcounter - 1;
-                afterVertex = vertexcounter - ( nPoints - 2 );
-              }
-              else
-              {
-                beforeVertex = vertexcounter - 1;
-                afterVertex = vertexcounter + 1;
-              }
-            }
-            if ( hasZValue ) //skip z-coordinate for 25D geometries
-            {
-              wkbPtr += sizeof( double );
-            }
-            ++vertexcounter;
-          }
-        }
-      }
-      break;
+      mCachedBaseData.push_back( QgsInterpolatorVertexData( ( *point ).x(), ( *point ).y(), attributeValue ) );
     }
-#endif //0
-    default:
-      break;
   }
   mDataIsCached = true;
-  return 0;
+  return true;
 }
diff --git a/src/analysis/interpolation/qgsinterpolator.h b/src/analysis/interpolation/qgsinterpolator.h
@@ -32,9 +32,26 @@ class QgsFeedback;
  */
 struct ANALYSIS_EXPORT QgsInterpolatorVertexData
 {
-  double x;
-  double y;
-  double z;
+
+  /**
+   * Constructor for QgsInterpolatorVertexData with the specified
+   * \a x, \a y, and \a z coordinate.
+   */
+  QgsInterpolatorVertexData( double x, double y, double z )
+    : x( x )
+    , y( y )
+    , z( z )
+  {}
+
+  //! Constructor for QgsInterpolatorVertexData
+  QgsInterpolatorVertexData() = default;
+
+  //! X-coordinate
+  double x = 0.0;
+  //! Y-coordinate
+  double y = 0.0;
+  //! Z-coordinate
+  double z = 0.0;
 };
 
 /**
@@ -55,7 +72,16 @@ class ANALYSIS_EXPORT QgsInterpolator
       SourceBreakLines, //!< Break lines
     };
 
-    //! A layer together with the information about interpolation attribute / z-coordinate interpolation and the type (point, structure line, breakline)
+    //! Result of an interpolation operation
+    enum Result
+    {
+      Success = 0, //!< Operation was successful
+      Canceled, //!< Operation was manually canceled
+      InvalidSource, //!< Operation failed due to invalid source
+      FeatureGeometryError, //!< Operation failed due to invalid feature geometry
+    };
+
+    //! A source together with the information about interpolation attribute / z-coordinate interpolation and the type (point, structure line, breakline)
     struct LayerData
     {
       //! Feature source
@@ -111,11 +137,12 @@ class ANALYSIS_EXPORT QgsInterpolator
 
     /**
      * Helper method that adds the vertices of a geometry to the mCachedBaseData
-       \param geom the geometry
-       \param zCoord true if the z-coordinate of the geometry is to be interpolated
-       \param attributeValue the attribute value for interpolation (if not interpolated from z-coordinate)
-     \returns 0 in case of success*/
-    int addVerticesToCache( const QgsGeometry &geom, bool zCoord, double attributeValue );
+     * \param geom the geometry
+     * \param zCoord true if the z-coordinate of the geometry is to be interpolated
+     * \param attributeValue the attribute value for interpolation (if not interpolated from z-coordinate)
+     *\returns 0 in case of success
+    */
+    bool addVerticesToCache( const QgsGeometry &geom, bool zCoord, double attributeValue );
 };
 
 #endif
