Cleaned up usage of RepropjectionTransformer.

Tweaked documentation.

Author: metasim

core/src/main/scala/org/locationtech/rasterframes/expressions/transformers/XZ2Indexer.scala

@@ -30,21 +30,22 @@ import org.apache.spark.sql.catalyst.expressions.{BinaryExpression, Expression,
 import org.apache.spark.sql.jts.JTSTypes
 import org.apache.spark.sql.rf.RasterSourceUDT
 import org.apache.spark.sql.types.{DataType, LongType}
-import org.apache.spark.sql.{Column, TypedColumn}
+import org.apache.spark.sql.{Column, TypedColumn, rf}
 import org.locationtech.geomesa.curve.XZ2SFC
-import org.locationtech.jts.geom.{Envelope, Geometry, GeometryFactory}
+import org.locationtech.jts.geom.{Envelope, Geometry}
 import org.locationtech.rasterframes.encoders.CatalystSerializer._
 import org.locationtech.rasterframes.expressions.DynamicExtractors._
+import org.locationtech.rasterframes.expressions.accessors.GetCRS
 import org.locationtech.rasterframes.expressions.row
 import org.locationtech.rasterframes.jts.ReprojectionTransformer
 import org.locationtech.rasterframes.ref.{RasterRef, RasterSource}
 import org.locationtech.rasterframes.tiles.ProjectedRasterTile
-import org.apache.spark.sql.rf
-import org.locationtech.rasterframes.expressions.accessors.GetCRS
 
 /**
   * Constructs a XZ2 index in WGS84 from either a Geometry, Extent, ProjectedRasterTile, or RasterSource
-  * See: https://www.geomesa.org/documentation/user/datastores/index_overview.html
+  * This function is useful for [range partitioning](http://spark.apache.org/docs/latest/api/python/pyspark.sql.html?highlight=registerjava#pyspark.sql.DataFrame.repartitionByRange).
+  * Also see: https://www.geomesa.org/documentation/user/datastores/index_overview.html
+  *
   * @param left geometry-like column
   * @param right CRS column
   * @param indexResolution resolution level of the space filling curve -
@@ -75,8 +76,6 @@ case class XZ2Indexer(left: Expression, right: Expression, indexResolution: Shor
   }
 
   private lazy val indexer = XZ2SFC(indexResolution)
-  @transient
-  private lazy val gf = new GeometryFactory()
 
   override protected def nullSafeEval(leftInput: Any, rightInput: Any): Any = {
     val crs = crsExtractor(right.dataType)(rightInput)
@@ -106,9 +105,9 @@ case class XZ2Indexer(left: Expression, right: Expression, indexResolution: Shor
     else {
       val trans = new ReprojectionTransformer(crs, LatLng)
       coords match {
-        case e: Extent => trans(e.jtsGeom).getEnvelopeInternal
+        case e: Extent => trans(e).getEnvelopeInternal
         case g: Geometry => trans(g).getEnvelopeInternal
-        case e: Envelope => trans(gf.toGeometry(e)).getEnvelopeInternal
+        case e: Envelope => trans(e).getEnvelopeInternal
       }
     }
 

core/src/main/scala/org/locationtech/rasterframes/jts/ReprojectionTransformer.scala

@@ -21,18 +21,24 @@
 
 package org.locationtech.rasterframes.jts
 
-import org.locationtech.jts.geom.{CoordinateSequence, Geometry}
+import org.locationtech.jts.geom.{CoordinateSequence, Envelope, Geometry, GeometryFactory}
 import org.locationtech.jts.geom.util.GeometryTransformer
 import geotrellis.proj4.CRS
+import geotrellis.vector.Extent
 
 /**
  * JTS Geometry reprojection transformation routine.
  *
  * @since 6/4/18
  */
 class ReprojectionTransformer(src: CRS, dst: CRS) extends GeometryTransformer {
-  def apply(geometry: Geometry): Geometry = transform(geometry)
   lazy val transform = geotrellis.proj4.Transform(src, dst)
+  @transient
+  private lazy val gf = new GeometryFactory()
+  def apply(geometry: Geometry): Geometry = transform(geometry)
+  def apply(extent: Extent): Geometry = transform(extent.jtsGeom)
+  def apply(env: Envelope): Geometry = transform(gf.toGeometry(env))
+
   override def transformCoordinates(coords: CoordinateSequence, parent: Geometry): CoordinateSequence = {
     val fact = parent.getFactory
     val retval = fact.getCoordinateSequenceFactory.create(coords)

pyrasterframes/src/main/python/docs/reference.pymd

@@ -73,7 +73,7 @@ Convert an extent to a Geometry. The extent likely comes from @ref:[`st_extent`]
     Long rf_spatial_index(Extent extent, CRS crs)
     Long rf_spatial_index(ProjectedRasterTile proj_raster, CRS crs)
 
-Constructs a XZ2 index in WGS84/EPSG:4326 from either a Geometry, Extent, ProjectedRasterTile and its CRS.
+Constructs a XZ2 index in WGS84/EPSG:4326 from either a Geometry, Extent, ProjectedRasterTile and its CRS. This function is useful for [range partitioning](http://spark.apache.org/docs/latest/api/python/pyspark.sql.html?highlight=registerjava#pyspark.sql.DataFrame.repartitionByRange).
 
 ## Tile Metadata and Mutation