chore: prevents write_xy_narray from writing incomplete blocks and ad…

…ds more tests

lib/gdal/extensions/raster_band/extensions.rb

@@ -30,7 +30,7 @@ def to_a
       #
       # @return [NArray]
       def to_na(to_data_type = nil)
-        narray = NArray.to_na(to_a)
+        narray = to_nna
 
         return narray unless to_data_type
 
@@ -40,7 +40,7 @@ def to_na(to_data_type = nil)
       end
 
       def to_nna
-        Numo::NArray[to_a]
+        NArray.to_na(to_a)
       end
 
       # Each pixel of the raster projected using the dataset's geo_transform.

lib/gdal/extensions/raster_band/io_extensions.rb

@@ -21,29 +21,32 @@ def readlines
         end
       end
 
-      # Writes a 2-dimensional NArray of (x, y) pixels to the raster band using
-      # {GDAL::RasterBand#raster_io}. It determines +x_size+ and +y_size+ for
-      # the {GDAL::RasterBand#raster_io} call using the dimensions of the array.
-      #
+      # Writes a 2-dimensional NArray of (x, y) pixels to the raster band block-by-block.
+      # Expects the input array to have the same shape as the raster band.
       # @param pixel_array [NArray] The 2d list of pixels.
       def write_xy_narray(pixel_array)
         data_pointer = FFI::MemoryPointer.new(:buffer_out, block_buffer_size)
-        read_start = 0
 
         block_count[:y].times do |y_block_number|
           block_count[:x].times do |x_block_number|
+            # Create a block-sized NArray of zeros. This represents the block of pixels that will be written.
+            block_pixels = NArray.to_na(Array.new(block_size[:y]) { Array.new(block_size[:x], 0) })
+
             y_block_size = calculate_y_block_size(y_block_number)
             x_block_size = calculate_x_block_size(x_block_number)
 
-            pixel_count_per_block = x_block_size * y_block_size
-            read_range = (read_start...(read_start + pixel_count_per_block))
-            pixels = pixel_array[read_range]
-            GDAL._write_pointer(data_pointer, data_type, pixels.to_a)
+            # Map the range of pixels corresponding to the current block.
+            source_x_range = x_block_number * block_size[:x]...(x_block_number * block_size[:x]) + x_block_size
+            source_y_range = y_block_number * block_size[:y]...(y_block_number * block_size[:y]) + y_block_size
+
+            # Copy the corresponding pixels from the input array to the block pixels.
+            block_pixels[0...x_block_size, 0...y_block_size] = pixel_array[source_x_range, source_y_range]
+
+            GDAL._write_pointer(data_pointer, data_type, block_pixels.to_a.flatten)
 
             write_block(x_block_number, y_block_number, data_pointer)
 
             data_pointer.clear
-            read_start = read_range.end
           end
         end
       end

spec/unit/gdal/extensions/raster_band/io_extensions_spec.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "gdal/driver"
-require "gdal/extensions/raster_band/io_extensions"
+require "gdal/extensions/raster_band/extensions"
 
 RSpec.describe "GDAL::RasterBand::IOExtensions" do
   let(:driver) { GDAL::Driver.by_name("MEM") }
@@ -156,6 +156,30 @@
   end
 
   describe "#read_lines_by_block" do
+    context "block size is larger than the raster" do
+      let(:rows) { (1..4).map { |i| Array.new(15) { i } } }
+
+      let(:dataset_path) do
+        filename = "/tmp/#{SecureRandom.uuid}.tif"
+        options = { BLOCKXSIZE: 256, BLOCKYSIZE: 256, TILED: "YES" }
+        GDAL::Driver.by_name("GTiff").create_dataset(filename, 15, 4, **options) do |dataset|
+          dataset.raster_band(1).write_xy_narray(NArray.to_na(rows))
+        end
+        filename
+      end
+
+      after { FileUtils.rm_f(dataset_path) }
+
+      let(:dataset) { GDAL::Dataset.open(dataset_path, "r") }
+
+      subject { dataset.raster_band(1) }
+
+      it "yields all block rows with correct values" do
+        expect { |b| subject.read_lines_by_block(&b) }
+          .to yield_successive_args(*rows)
+      end
+    end
+
     context "block is given" do
       it "yields each row of pixels" do
         expect { |b| subject.read_lines_by_block(&b) }

spec/unit/gdal/extensions/raster_band_classifier_spec.rb

@@ -2,6 +2,7 @@
 
 require "gdal/driver"
 require "gdal/extensions/raster_band_classifier"
+require "gdal/extensions/raster_band/extensions"
 
 RSpec.describe GDAL::RasterBandClassifier do
   let(:driver) { GDAL::Driver.by_name("MEM") }