Some ported examples in algebra mode

examples/lego_algebra.py

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+from alg123d import *
+
+pip_count = 6
+
+lego_unit_size = 8
+pip_height = 1.8
+pip_diameter = 4.8
+block_length = lego_unit_size * pip_count
+block_width = 16
+base_height = 9.6
+block_height = base_height + pip_height
+support_outer_diameter = 6.5
+support_inner_diameter = 4.8
+ridge_width = 0.6
+ridge_depth = 0.3
+wall_thickness = 1.2
+
+
+# Draw the bottom of the block
+
+# Start with a Rectangle the size of the block
+plan = Rectangle(width=block_length, height=block_width)
+
+# Subtract an offset to create the block walls
+plan -= offset(
+    plan,
+    amount=-wall_thickness,
+    kind=Kind.INTERSECTION,
+)
+# Add a grid of lengthwise and widthwise bars
+for loc in GridLocations(x_spacing=0, y_spacing=lego_unit_size, x_count=1, y_count=2):
+    plan += loc * Rectangle(width=block_length, height=ridge_width)
+
+for loc in GridLocations(lego_unit_size, 0, pip_count, 1):
+    plan += loc * Rectangle(width=ridge_width, height=block_width)
+
+# Substract a rectangle leaving ribs on the block walls
+plan -= Rectangle(
+    block_length - 2 * (wall_thickness + ridge_depth),
+    block_width - 2 * (wall_thickness + ridge_depth),
+)
+# Add a row of hollow circles to the center
+for loc in GridLocations(
+    x_spacing=lego_unit_size, y_spacing=0, x_count=pip_count - 1, y_count=1
+):
+    plan += loc * Circle(support_outer_diameter / 2)
+    plan -= loc * Circle(support_inner_diameter / 2)
+
+# Extrude this base sketch to the height of the walls
+lego = extrude(plan, amount=base_height - wall_thickness)
+
+# Create a box on the top of the walls
+for loc in Locations((0, 0, lego.vertices().max().Z)):
+    # Create the top of the block
+    lego += loc * Box(
+        length=block_length,
+        width=block_width,
+        height=wall_thickness,
+        align=(Align.CENTER, Align.CENTER, Align.MIN),
+    )
+
+# Create a workplane on the top of the block
+plane = Plane(lego.faces().max())
+
+# Create a grid of pips
+for loc in GridLocations(lego_unit_size, lego_unit_size, pip_count, 2):
+    lego += (
+        plane
+        * loc
+        * Cylinder(
+            radius=pip_diameter / 2,
+            height=pip_height,
+            align=(Align.CENTER, Align.CENTER, Align.MIN),
+        )
+    )
+
+if "show_object" in locals():
+    show_object(lego, name="lego")