Merge pull request #54 from fugro-oss/FixSynthFlagHandling

Fix synth flag handling

Author: BenCurran98

Project.toml

@@ -1,7 +1,7 @@
 name = "LASDatasets"
 uuid = "cc498e2a-d443-4943-8f26-2a8a0f3c7cdb"
 authors = ["BenCurran98 <b.curran@fugro.com>"]
-version = "0.4.2"
+version = "0.4.3"
 
 [deps]
 BufferedStreams = "e1450e63-4bb3-523b-b2a4-4ffa8c0fd77d"

src/header.jl

@@ -853,7 +853,7 @@ function make_consistent_header!(header::LasHeader,
 
     set_point_data_offset!(header, point_data_offset)
 
-    _consolidate_point_header_info!(header, pointcloud)
+    _consolidate_point_header_info!(header, pointcloud)    
 
     if !isempty(vlrs)
         set_num_vlr!(header, length(vlrs))
@@ -891,8 +891,13 @@ function _consolidate_point_header_info!(header::LasHeader, pointcloud::Abstract
     returns = (:returnnumber ∈ columnnames(pointcloud)) ? pointcloud.returnnumber : ones(Int, length(pointcloud))
     points_per_return = ntuple(r -> count(returns .== r), num_return_channels(header))
     set_number_of_points_by_return!(header, points_per_return)
+    # check if we have any synthetic points and update the global encoding bit accordingly
     if :synthetic ∈ columnnames(pointcloud)
-        set_synthetic_return_numbers_bit!(header)
+        if any(pointcloud.synthetic)
+            set_synthetic_return_numbers_bit!(header)
+        else
+            unset_synthetic_return_numbers_bit!(header)
+        end
     else
         unset_synthetic_return_numbers_bit!(header)
     end

test/dataset.jl

@@ -50,6 +50,20 @@
     LASDatasets.make_consistent_header!(h, pc, LasVariableLengthRecord[], LasVariableLengthRecord[], UInt8[])
     las = LASDataset(h, pc, LasVariableLengthRecord[], LasVariableLengthRecord[], UInt8[])
     @test las == LASDataset(deepcopy(pc))
+
+    # check how we're modifying the synthetic flag - if we have no synthetics, it shouldn't be set
+    just_synth_flag(global_encoding::UInt16) = global_encoding & 0x0008
+    @test just_synth_flag(h.global_encoding) == 0x00
+    # but if we set some, our flag should be adjusted
+    pc = Table(pc, synthetic = trues(num_points))
+    h = LasHeader(; las_version = v"1.1", data_format_id = UInt8(1), data_record_length = UInt16(28))
+    LASDatasets.make_consistent_header!(h, pc, LasVariableLengthRecord[], LasVariableLengthRecord[], UInt8[])
+    @test just_synth_flag(h.global_encoding) > 0
+    # if we set all these to false, though, then we shouldn't set the flag either
+    pc.synthetic .= false
+    LASDatasets.make_consistent_header!(h, pc, LasVariableLengthRecord[], LasVariableLengthRecord[], UInt8[])
+    @test just_synth_flag(h.global_encoding) == 0x00
+    
 
     # now try incorporating some user fields
     spicy_pc = Table(pc, thing = rand(num_points), other_thing = rand(Int16, num_points))
@@ -58,7 +72,7 @@
     this_header = get_header(las)
     @test point_record_length(this_header) == LASDatasets.byte_size(LasPoint1) + 10
     # our user fields should be populated in the dataset
-    @test sort(collect(columnnames(las.pointcloud))) == [:classification, :gps_time, :id, :other_thing, :position, :thing]
+    @test sort(collect(columnnames(las.pointcloud))) == [:classification, :gps_time, :id, :other_thing, :position, :synthetic, :thing]
     this_pc = get_pointcloud(las)
     @test this_pc.thing == spicy_pc.thing
     @test this_pc.other_thing == spicy_pc.other_thing