From 61e591b5b811438ff36e4347f94c6c89f222b7b7 Mon Sep 17 00:00:00 2001 From: jaseg Date: Fri, 22 Sep 2023 18:50:58 +0200 Subject: WiP --- docs/ex-mask-islands.png | Bin 0 -> 248805 bytes docs/examples.rst | 64 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 64 insertions(+) create mode 100644 docs/ex-mask-islands.png create mode 100644 docs/examples.rst (limited to 'docs') diff --git a/docs/ex-mask-islands.png b/docs/ex-mask-islands.png new file mode 100644 index 0000000..b600738 Binary files /dev/null and b/docs/ex-mask-islands.png differ diff --git a/docs/examples.rst b/docs/examples.rst new file mode 100644 index 0000000..a795a73 --- /dev/null +++ b/docs/examples.rst @@ -0,0 +1,64 @@ +.. _examples-doc: + +Examples +======== + +Solder mask rings +----------------- + +This example script takes a board exported with a more recent KiCad version, and removes solder mask everywhere, but +leaves a thin ring of solder mask around every pad. Might be useful for some artsy boards. + +.. image:: ex-mask-islands.png + +.. code-block:: python + from gerbonara import * + from shapely import * + + stack = layers.LayerStack.open('gerber') + # Let's work in mm here. Gerbonara will take care to convert units when the file is in US customary units. + (x1, y1), (x2, y2) = stack.bounding_box(unit=utils.MM) + + for l in [stack['bottom mask'], stack['top mask']]: + + # The solder mask gerber layer by convention is "negative". That is, a "dark" polarity (drawn) Gerber primitive + # will result in an opening in the solder mask. Conversely, an empty gerber file would lead to the entire board + # being covered in solder mask. + # + # Here, we add a rectangle covering the entire board so the entire board is *free* of solder mask. + + new = [graphic_objects.Region( + [(x1, y1), (x1, y2), (x2, y2), (x2, y1), (x1, y1)], + unit=utils.MM, + polarity_dark=True)] + + # Iterate through all objects on the solder mask layer. In later KiCad versions, everything on the solder mask + # layer is exported as a Gerber region, which is a really bad idea, but makes things easy for us here. + for obj in l.objects: + if isinstance(obj, gerbonara.graphic_objects.Region): + regions = [] + else: + regions = [gerbonara.graphic_objects.Region.from_arc_poly(prim.to_arc_poly()) + for prim in obj.to_primitives(unit=gerbonara.utils.MM)] + + for obj in regions: + # Convert the region to a shapely line string + ls = LineString(obj.outline).normalize() + + # Ask shapely to offset the line string by 1 mm + out = ls.offset_curve(obj.unit(1, 'mm')) + + # For negative offsets, this operation can result in an object being split up into multiple parts, so we + # might get back a MultiLineString instead of a LineString. + for ls in (out.geoms if hasattr(out, 'geoms') else [out]): + + # Convert the resulting shapely object back to a Gerber region. + new.append(graphic_objects.Region( + unit=obj.unit, + polarity_dark=not obj.polarity_dark, + outline=list(ls.coords))) + + # Append the new objects to the original layer data + l.objects = new + l.objects + # Write the modified layer stack to a new Gerber directory + stack.save_to_directory('output-gerbers') -- cgit