WiP

1 files changed, 53 insertions, 0 deletions

diff --git a/test2.py b/test2.py
new file mode 100644
index 0000000..72626db
--- /dev/null
+++ b/test2.py
@@ -0,0 +1,53 @@
+from gerbonara import *
+from shapely import *
+
+stack = layers.LayerStack.open('/home/jaseg/proj/ihsm-strain-gage-controller-hw/pcb/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 not obj.polarity_dark:
+            continue
+
+        if isinstance(obj, graphic_objects.Region):
+            regions = []
+        else:
+            regions = [graphic_objects.Region.from_arc_poly(prim.to_arc_poly())
+                for prim in obj.to_primitives(unit=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('/tmp/out')