rename writers.gdal.edge_length to writers.gdal.resolution. Allow set…

…ting of nodata in options

doc/stages/writers.gdal.rst

@@ -20,7 +20,7 @@ potentially contributes to the raster's value.
     it is possible that some points will not be considered at all, including
     those that may be within the bounds of the raster cell.
 
-The GDAL writer creates rasters using the data in the 'Z' dimension of the 
+The GDAL writer creates rasters using the data in the 'Z' dimension of the
 points.  In a :ref:`pipeline_command` one can precede the GDAL writer with
 the ferry filter (:ref:`filters.ferry`) in order to copy data from some
 other dimension to the 'Z' dimension if desired.
@@ -78,7 +78,7 @@ whose values contribute to the cell value is 14.14.
       "pipeline":[
         "pdal/test/data/las/autzen_trim.las",
         {
-          "edge_length": 10,
+          "resolution": 10,
           "radius": 14.14,
           "filename":"outputfile.tif"
         }
@@ -92,8 +92,8 @@ Options
 filename
     Name of output file. [Required]
 
-edge_length
-    Length of raster cell edges.  [Required]
+resolution
+    Length of raster cell edges in X/Y units.  [Required]
 
 radius
     Radius about cell center bounding points to use to calculate a cell value.

io/gdal/GDALWriter.cpp

@@ -59,7 +59,7 @@ std::string GDALWriter::getName() const
 void GDALWriter::addArgs(ProgramArgs& args)
 {
     args.add("filename", "Output filename", m_filename).setPositional();
-    args.add("edge_length", "Length of cell edges (cells are square)",
+    args.add("resolution", "Cell edge size, in units of X/Y",
         m_edgeLength).setPositional();
     args.add("radius", "Radius from cell center to use to locate influencing "
         "points", m_radius).setPositional();
@@ -70,6 +70,7 @@ void GDALWriter::addArgs(ProgramArgs& args)
         "'idw', 'count', 'stdev' or 'all')", m_outputTypeString, {"all"} );
     args.add("window_size", "Cell distance for fallback interpolation",
         m_windowSize);
+    args.add("nodata", "No data value", m_noData, -9999.0);
 }
 
 
@@ -124,7 +125,7 @@ void GDALWriter::write(const PointViewPtr view)
     view->calculateBounds(m_bounds);
     size_t width = ((m_bounds.maxx - m_bounds.minx) / m_edgeLength) + 1;
     size_t height = ((m_bounds.maxy - m_bounds.miny) / m_edgeLength) + 1;
-    m_grid.reset(new GDALGrid(width, height, m_edgeLength, m_radius, -9999.0,
+    m_grid.reset(new GDALGrid(width, height, m_edgeLength, m_radius, m_noData,
         m_outputTypes, m_windowSize));
 
     for (PointId idx = 0; idx < view->size(); ++idx)
@@ -152,7 +153,7 @@ void GDALWriter::done(PointTableRef table)
     pixelToPos[5] = -m_edgeLength;
     gdal::Raster raster(m_filename, m_drivername, table.spatialReference(),
         pixelToPos);
-    
+
     m_grid->finalize();
 
     gdal::GDALError err = raster.open(m_grid->width(), m_grid->height(),

io/gdal/GDALWriter.hpp

@@ -72,6 +72,7 @@ class PDAL_DLL GDALWriter : public Writer
     size_t m_windowSize;
     int m_outputTypes;
     GDALGridPtr m_grid;
+    double m_noData;
 };
 
 }