| BlueSpray - Help © SchoonerTurtles, Inc. 2012-2015
Introduction
Contents
Getting Started
Download
Navigating
Tutorials
Scripting
Advanced
About
| # Class STOverlayLayers Extends STTransformVector Spatially adds (union), subtracts, insertects, or finds the symetric difference between the features in one layer from the features in another layer. The features in both layers can be filtered based on selection. Attributes can also be specified to be matched in each layer to have features operated on by the matching features in the other layer. Regardless, the operation is that for each layer in the first input layer: - The features in the second layer are combined and then used to operate on the feature in the first layer. - The features in the second layer are either all combined or they can be filtered by the ones that are selected or by matching attribute values in the first layer. If an attribute column is provided in either layer, then each feature is operated against each matching feature. No Attributes specified: The second input layer is combined into a single geometry that is used to operate on each feature in the first layer Attribute columns specified in each layer: The layers features are operated on by the matching features from the second input layer. @author Jim Graham Copyright, SchoonerTurtles LLP, 2009 #### Enumerated Types OVERLAY_OPERATION UNION - Union (Add) SUBTRACT - Subtract INTERSECTION - Intersection SYMETRIC_DIFFERENCE - Symetric Difference #### Static Functions
Returns | Function | Throws
--- | --- | ---
Geometry | Operate(Geometry TheGeometry1,Geometry TheGeometry2, OVERLAY_OPERATION TheOperator) | Exception
| Operate(STLayerVectors Input0,int AttributeColumn0,boolean SelectedOnly0, STLayerVectors Input1,int AttributeColumn1,boolean SelectedOnly1, OVERLAY_OPERATION TheOperator,STLayerVectors Output) | Exception
## Static Functions ### Geometry Operate(Geometry TheGeometry1,Geometry TheGeometry2, OVERLAY_OPERATION TheOperator) Exception Performs an operation on two geometries and returns the result. This function takes care of the problems the JTS has with geometry collections. The JTS library does not like getting null geometries (it throws exceptions) so they are handled before calling the library. Parameters: TheGeometry1 TheGeometry2 TheOperator Returns: ### Operate(STLayerVectors Input0,int AttributeColumn0,boolean SelectedOnly0, STLayerVectors Input1,int AttributeColumn1,boolean SelectedOnly1, OVERLAY_OPERATION TheOperator,STLayerVectors Output) Exception Perform a spatial operation based on the settings. Parameters: Input0 - the first vector layer (points, polyline, or polygon) AttributeColumn0 - an optional attribute column to only operate on matching values in the attribute columns, -1 for none SelectedOnly0 - true to just use the selected values Input1 - second vector layer AttributeColumn1 - attribute column in the second layer, if an attribute column is specific for the first layer, then this one must be specified as well SelectedOnly1 - true to just use the seleced values TheOperator - type of operation to execute Output - the layer for the output Throws: Exception