Make createAlignedGridExtent actually align to GridExtents

[jpolchlo]

Overview

The sad state of affairs before this PR:

scala> GridExtent(Extent(0,0,3.5,3.5), 1.0, 1.0)
res12: geotrellis.raster.GridExtent = GridExtent(Extent(0.0, 0.0, 3.5, 3.5),1.0,1.0)

scala> res12.createAlignedRasterExtent(res12.extent)
res13: geotrellis.raster.RasterExtent = GridExtent(Extent(0.0, 0.0, 3.5, 3.5),1.0,1.0)

scala> res12.createAlignedRasterExtent(Extent(0,0,3.8,3.8))
res14: geotrellis.raster.RasterExtent = GridExtent(Extent(0.0, 0.0, 4.5, 4.5),1.0,1.0)

I fixed it and introduced the possibility that the alignment point (a point at the intersection of the target cell grid) might be specified by the user (in case one wanted the grid to align to a point other than the upper left of the GridExtent's extent):

scala> GridExtent(Extent(0,0,3.5,3.5), 1.0, 1.0)
res0: geotrellis.raster.GridExtent = GridExtent(Extent(0.0, 0.0, 3.5, 3.5),1.0,1.0)

scala> res0.createAlignedGridExtent(res0.extent)
res1: geotrellis.raster.GridExtent = GridExtent(Extent(0.0, -0.5, 4.0, 3.5),1.0,1.0)

scala> res0.createAlignedGridExtent(res0.extent, Point(0,0))
res2: geotrellis.raster.GridExtent = GridExtent(Extent(0.0, 0.0, 4.0, 4.0),1.0,1.0)

Signed-off-by: jpolchlo [email protected]

Checklist

• docs/CHANGELOG.rst updated, if necessary
• docs guides update, if necessary
• New user API has useful Scaladoc strings
• Unit tests added for bug-fix or new feature

[pomadchin]

Actually this behaves now correct and like GDAL (with an alignment point (0,0)) https://github.com/geotrellis/geotrellis-contrib/blob/be70b10e2e06b0e089d911164cad3e30f27abdb1/vlm/src/main/scala/geotrellis/contrib/vlm/gdal/package.scala#L41