Some ported examples in algebra mode

examples/din_rail_algebra.py

@@ -0,0 +1,50 @@
+from alg123d import *
+
+# 35x7.5mm DIN Rail Dimensions
+overall_width, top_width, height, thickness, fillet_radius = 35, 27, 7.5, 1, 0.8
+rail_length = 1000
+slot_width, slot_length, slot_pitch = 6.2, 15, 25
+
+din = Rectangle(overall_width, thickness, align=(Align.CENTER, Align.MIN))
+din += Rectangle(top_width, height, align=(Align.CENTER, Align.MIN))
+din -= Rectangle(
+    top_width - 2 * thickness,
+    height - thickness,
+    align=(Align.CENTER, Align.MIN),
+)
+
+inside_vertices = (
+    din.vertices()
+    .filter_by_position(Axis.Y, 0.0, height, inclusive=(False, False))
+    .filter_by_position(
+        Axis.X,
+        -overall_width / 2,
+        overall_width / 2,
+        inclusive=(False, False),
+    )
+)
+
+din = fillet(din, inside_vertices, radius=fillet_radius)
+
+outside_vertices = filter(
+    lambda v: (v.Y == 0.0 or v.Y == height)
+    and -overall_width / 2 < v.X < overall_width / 2,
+    din.vertices(),
+)
+din = fillet(din, outside_vertices, radius=fillet_radius + thickness)
+
+rail = extrude(din, rail_length)
+
+plane = Plane(rail.faces().max(Axis.Y))
+
+with LazyAlgCompound() as slot_faces:
+    for loc in GridLocations(0, slot_pitch, 1, rail_length // slot_pitch - 1):
+        slot_faces += plane * loc * SlotOverall(slot_length, slot_width)
+
+slots = extrude(slot_faces, -height)
+
+rail -= slots
+rail = Plane.XZ * rail
+
+if "show_object" in locals():
+    show_object(rail, name="rail")