Add merge-convert png command

src/pygerber/console/gerber.py

@@ -10,6 +10,7 @@
 
 from pygerber.gerber import formatter
 from pygerber.gerber.api import Color, FileTypeEnum, GerberFile, Style
+from pygerber.gerber.api._composite_view import CompositeView
 from pygerber.vm.shapely.vm import is_shapely_available
 from pygerber.vm.types.color import InvalidHexColorLiteralError
 
@@ -498,22 +499,45 @@ def format_cmd(
         file.format(f, options=options)
 
 
-@gerber.command("project")
-@click.argument("files", nargs=-1)
-@click.option(
-    "-o",
-    "--output",
-    type=click.Path(dir_okay=False),
-    default="output.png",
-    help="Path to output file.",
-)
-@click.option("-d", "--dpmm", type=int, default=20, help="Dots per millimeter.")
-def _project(files: str, output: str, dpmm: int) -> None:
-    """Render multiple Gerber files and merge them layer by layer.
+@gerber.group("merge-convert")
+def merge_convert() -> None:
+    """Convert multiple Gerber images to different image format and merge them into one
+    image (stack on top of each other).
+    """
 
-    Layers are merged from first to last, thus last layer will be on top.
+
+@merge_convert.command("png")
+@click.argument("sources", nargs=-1)
+@_get_output_file_option()
+@_get_dpmm_option()
+@_get_file_type_option()
+@_get_raster_implementation_option("pillow")
+def merge_convert_png(
+    sources: str,
+    output: str,
+    file_type: str,
+    dpmm: int,
+    implementation: str,
+) -> None:
+    """Convert multiple Gerber images to PNG image and merge them into one image.
+
+    Images are merged from first to last, thus fist layer is bottom most, last layer
+    is topmost, unobstructed.
+
+    SOURCES - paths to files which are supposed to be rendered and merged.
     """
-    raise NotImplementedError
+    view = CompositeView(
+        GerberFile.from_file(source, file_type=FileTypeEnum(file_type.upper()))
+        for source in sources
+    )
+
+    if implementation.lower() == "pillow":
+        result = view.render_with_pillow(dpmm)
+        result.save_png(output)
+
+    else:
+        msg = f"Implementation {implementation!r} is not supported."
+        raise NotImplementedError(msg)
 
 
 @gerber.command("lint")

src/pygerber/examples/__init__.py

@@ -18,7 +18,6 @@ class ExamplesEnum(Enum):
 
     carte_test_B_Cu = "carte_test-B_Cu.gbr"  # noqa: N815
     carte_test_B_Mask = "carte_test-B_Mask.gbr"  # noqa: N815
-    carte_test_B_Paste = "carte_test-B_Paste.gbr"  # noqa: N815
     carte_test_B_Silkscreen = "carte_test-B_Silkscreen.gbr"  # noqa: N815
 
     carte_test_Edges = "carte_test-Edge_Cuts.gbr"  # noqa: N815

src/pygerber/gerber/api/_composite_view.py

@@ -5,7 +5,7 @@
 from PIL import Image
 
 from pygerber.gerber.api._enums import COLOR_MAP_T
-from pygerber.gerber.api._gerber_file import GerberFile, PillowImage
+from pygerber.gerber.api._gerber_file import GerberFile, PillowImage, _PillowSaveMixin
 
 if TYPE_CHECKING:
     from typing_extensions import Self
@@ -15,7 +15,7 @@ class CompositeImage:
     """Image composed of multiple sub-images."""
 
 
-class CompositePillowImage(CompositeImage):
+class CompositePillowImage(CompositeImage, _PillowSaveMixin):
     """Image composed of multiple sub-images."""
 
     def __init__(self, sub_images: list[PillowImage], image: Image.Image) -> None:

src/pygerber/gerber/api/_gerber_file.py

@@ -181,14 +181,8 @@ def get_image_space(self) -> ImageSpace:
         return self._image_space
 
 
-class PillowImage(Image):
-    """The `PillowImage` class is a rendered image returned by
-    `GerberFile.render_with_pillow` method.
-    """
-
-    def __init__(self, image_space: ImageSpace, image: PIL.Image.Image) -> None:
-        super().__init__(image_space=image_space)
-        self._image = image
+class _PillowSaveMixin:
+    """Mixin providing common methods for saving Pillow images."""
 
     def save(
         self,
@@ -332,6 +326,20 @@ def save_webp(
         """
         self.get_image().convert("RGB").save(fp=destination, format="WEBP", **kwargs)
 
+    def get_image(self) -> PIL.Image.Image:
+        """Get image object."""
+        raise NotImplementedError
+
+
+class PillowImage(Image, _PillowSaveMixin):
+    """The `PillowImage` class is a rendered image returned by
+    `GerberFile.render_with_pillow` method.
+    """
+
+    def __init__(self, image_space: ImageSpace, image: PIL.Image.Image) -> None:
+        super().__init__(image_space=image_space)
+        self._image = image
+
     def get_image(self) -> PIL.Image.Image:
         """Get image object."""
         return self._image

test/assets/reference/pygerber/console/gerber.py

@@ -43,3 +43,8 @@
         "reference/pygerber/console/test_gerber_format.formatted.gbr"
     )
 )
+
+MERGE_CONVERT_PNG_REFERENCE_IMAGE = ImageAsset[GitFile].new(
+    REFERENCE_REPOSITORY.file("reference/pygerber/console/merge_convert_png.png"),
+    ImageFormat.PNG,
+)

test/unit/test_gerber/test_console/test_gerber.py → test/unit/test_console/test_gerber.py

@@ -6,7 +6,15 @@
 from click.testing import CliRunner
 from PIL import Image
 
-from pygerber.console.gerber import bmp, format_cmd, jpeg, png, tiff, webp
+from pygerber.console.gerber import (
+    bmp,
+    format_cmd,
+    jpeg,
+    merge_convert_png,
+    png,
+    tiff,
+    webp,
+)
 from pygerber.examples import ExamplesEnum, get_example_path
 from pygerber.vm.shapely.vm import is_shapely_available
 from test.assets.assetlib import ImageAnalyzer, SvgImageAsset
@@ -19,6 +27,7 @@
     CONVERT_WEBP_LOSSLESS_REFERENCE_IMAGE,
     CONVERT_WEBP_LOSSY_REFERENCE_IMAGE,
     FORMAT_CMD_REFERENCE_CONTENT,
+    MERGE_CONVERT_PNG_REFERENCE_IMAGE,
 )
 from test.conftest import cd_to_tempdir
 from test.tags import Tag, tag
@@ -313,3 +322,40 @@ def test_gerber_format_cmd(*, is_regeneration_enabled: bool) -> None:
             pytest.skip("Reference updated")
         else:
             assert FORMAT_CMD_REFERENCE_CONTENT.load() == file_path.read_text()
+
+
+MIN_MERGE_PNG_SSIM = 0.99
+
+
+@tag(Tag.PILLOW, Tag.OPENCV, Tag.SKIMAGE)
+def test_gerber_merge_convert_png(*, is_regeneration_enabled: bool) -> None:
+    runner = CliRunner()
+    with cd_to_tempdir() as temp_path:
+        result = runner.invoke(
+            merge_convert_png,
+            [
+                get_example_path(ExamplesEnum.carte_test_B_Cu).as_posix(),
+                get_example_path(ExamplesEnum.carte_test_B_Mask).as_posix(),
+                get_example_path(ExamplesEnum.carte_test_B_Silkscreen).as_posix(),
+                "-o",
+                "output.png",
+                "-d",
+                "20",
+            ],
+        )
+        logging.debug(result.output)
+        assert result.exit_code == 0
+        assert (temp_path / "output.png").exists()
+
+        image = Image.open(temp_path / "output.png")
+        if is_regeneration_enabled:
+            MERGE_CONVERT_PNG_REFERENCE_IMAGE.update(image)  # pragma: no cover
+        else:
+            ia = ImageAnalyzer(MERGE_CONVERT_PNG_REFERENCE_IMAGE.load())
+            assert ia.structural_similarity(image) > MIN_MERGE_PNG_SSIM
+            ia.assert_same_size(image)
+            (
+                ia.histogram_compare_color(image)
+                .assert_channel_count(4)
+                .assert_greater_or_equal_values(0.99)
+            )