Update offset() parameter handling.

- Rounded offset is now using parameter r
- Using delta only or delta with camfer = false creates no chamfer
- Using delta with chamfer =true creates chamfer at delta distance

src/offset.cc

@@ -54,7 +54,7 @@ AbstractNode *OffsetModule::instantiate(const Context *ctx, const ModuleInstanti
 	OffsetNode *node = new OffsetNode(inst);
 
 	AssignmentList args;
-	args += Assignment("delta");
+	args += Assignment("r");
 
 	Context c(ctx);
 	c.setVariables(args, evalctx);
@@ -64,30 +64,25 @@ AbstractNode *OffsetModule::instantiate(const Context *ctx, const ModuleInstanti
 	node->fs = c.lookup_variable("$fs")->toDouble();
 	node->fa = c.lookup_variable("$fa")->toDouble();
 
-	ValuePtr delta = c.lookup_variable("delta");
+	// default with no argument at all is round / delta = 1
+	// radius takes precedence if both r and delta are given.
 	node->delta = 1;
-	delta->getDouble(node->delta);
+	node->chamfer = false;
+	node->join_type = ClipperLib::jtRound;
+	const ValuePtr r = c.lookup_variable("r", true);
+	const ValuePtr delta = c.lookup_variable("delta", true);
+	const ValuePtr chamfer = c.lookup_variable("chamfer", true);
 	
-	ValuePtr miter_limit = c.lookup_variable("miter_limit", true);
-	node->miter_limit = 2;
-	miter_limit->getDouble(node->miter_limit);
-	
-	ValuePtr join_type = c.lookup_variable("join_type", true);
-	if (join_type->type() == Value::STRING) {
-		std::string jt = join_type->toString();
-		if (std::string("bevel") == jt) {
-			node->join_type = ClipperLib::jtSquare;
-		} else if (std::string("round") == jt) {
-			node->join_type = ClipperLib::jtRound;
-		} else if (std::string("miter") == jt) {
-			node->join_type = ClipperLib::jtMiter;
-		} else {
-			PRINTB("WARNING: Unknown join_type for offset(): '%s'", jt);
-		}
-		
-		if ((node->join_type != ClipperLib::jtMiter) && !miter_limit->isUndefined()) {
-			PRINTB("WARNING: miter_limit is ignored in offset() for join_type: '%s'", jt);
-		}
+	if (r->isDefinedAs(Value::NUMBER)) {
+	    r->getDouble(node->delta);
+	} else if (delta->isDefinedAs(Value::NUMBER)) {
+	    delta->getDouble(node->delta);
+
+	    node->join_type = ClipperLib::jtMiter;
+	    if (chamfer->isDefinedAs(Value::BOOL) && chamfer->toBool()) {
+		node->chamfer = true;
+		node->join_type = ClipperLib::jtSquare;
+	    }
 	}
 	
 	std::vector<AbstractNode *> instantiatednodes = inst->instantiateChildren(evalctx);
@@ -100,21 +95,17 @@ std::string OffsetNode::toString() const
 {
 	std::stringstream stream;
 
-	stream  << this->name()
-		<< "(delta = " << std::dec << this->delta
-		<< ", join_type = \""
-			<< (this->join_type == ClipperLib::jtSquare
-				? "bevel"
-				: this->join_type == ClipperLib::jtRound
-					? "round"
-					: "miter") << "\"";
-	if (this->join_type == ClipperLib::jtMiter) {
-		stream << ", miter_limit = " << this->miter_limit;
+	bool isRadius = this->join_type == ClipperLib::jtRound;
+	const char *var = isRadius ? "(r = " : "(delta = ";
+
+	stream  << this->name() << var << std::dec << this->delta;
+	if (!isRadius) {
+	    stream << ", chamfer = " << (this->chamfer ? "true" : "false");
 	}
 	stream  << ", $fn = " << this->fn
 		<< ", $fa = " << this->fa
 		<< ", $fs = " << this->fs << ")";
-	
+
 	return stream.str();
 }
 

src/offsetnode.h

@@ -8,13 +8,15 @@
 class OffsetNode : public AbstractPolyNode
 {
 public:
-	OffsetNode(const ModuleInstantiation *mi) : AbstractPolyNode(mi), fn(0), fs(0), fa(0), delta(1), miter_limit(2.0), join_type(ClipperLib::jtMiter) { }
+	OffsetNode(const ModuleInstantiation *mi) : AbstractPolyNode(mi), fn(0), fs(0), fa(0), delta(1), miter_limit(1000000.0), join_type(ClipperLib::jtRound) { }
         virtual Response accept(class State &state, Visitor &visitor) const {
 		return visitor.visit(state, *this);
 	}
 	virtual std::string toString() const;
 	virtual std::string name() const { return "offset"; }
 
-	double fn, fs, fa, delta, miter_limit;
+        bool chamfer;
+	double fn, fs, fa, delta;
+        double miter_limit; // currently fixed high value to disable chamfers with jtMiter
         ClipperLib::JoinType join_type;
 };

src/value.cc

@@ -130,9 +130,19 @@ Value::ValueType Value::type() const
   return static_cast<ValueType>(this->value.which());
 }
 
+bool Value::isDefined() const
+{
+  return this->type() != UNDEFINED;
+}
+
+bool Value::isDefinedAs(const ValueType type) const
+{
+  return this->type() == type;
+}
+
 bool Value::isUndefined() const
 {
-  return this->type() == UNDEFINED;
+  return !isDefined();
 }
 
 bool Value::toBool() const

src/value.h

@@ -117,6 +117,8 @@ public:
   ~Value() {}
 
   ValueType type() const;
+  bool isDefined() const;
+  bool isDefinedAs(const ValueType type) const;
   bool isUndefined() const;
 
   double toDouble() const;

testdata/scad/2D/features/offset-tests.scad

@@ -1,46 +1,55 @@
-
-module shape1(x, y) {
-	translate([50 * x, 50 * y]) difference() {
-		square([30, 30], center = true);
-		square([8, 8], center = true);
-	}
+module m(x, y) {
+    translate(60 * [x, y]) children();
 }
 
-module shape2(x, y) {
-	translate([50 * x, 50 * y]) {
-		polygon(points=[
-			[-15, 80],[15, 80],[0,-15],[-8, 60],[8, 60],[0, 5]
-		], paths=[
-			[0,1,2],[3,4,5]
-		]);
-	}
+module shape1(w = 20) {
+    difference() {
+        square([ w,  w], center = true);
+        square([10, 10], center = true);
+    }
 }
 
-offset(delta = -1, join_type = "miter") shape2(-1, 2);
-shape2(0, 2);
-offset(delta = 1, join_type = "miter") shape2(1, 2);
+module shape2() {
+    polygon(points=[
+            [-15, 80],[15, 80],[0,-15],[-8, 60],[8, 60],[0, 5]
+    ], paths=[
+            [0,1,2],[3,4,5]
+    ]);
+}
 
-offset(delta = -1, join_type = "miter", miter_limit = 10) shape2(2, 2);
-offset(delta = 1, join_type = "miter", miter_limit = 10) shape2(3, 2);
+m(-1, 0) shape1();
+m(-1, 2) shape2();
 
-offset(delta = -1, join_type = "bevel") shape2(2, -1);
-offset(delta = 1, join_type = "bevel") shape2(3, -1);
+m(0, 0) offset() shape1();
+m(0, 1) offset(5) shape1();
+m(0, 2) offset(5) shape2();
 
-offset(delta = -5, join_type = "round") shape1(-1, 1);
-shape1(0, 1);
-offset(delta = 5, join_type = "round") shape1(1, 1);
+m(1, 0) offset(r = 1) shape1(30);
+m(1, 1) offset(r = 5) shape1(30);
+m(1, 2) offset(r = 5) shape2();
 
-offset(-4) shape1(-1, 0);
-shape1(0, 0);
-offset(4) shape1(1, 0);
+m(2, 0) offset(r = -5) shape1(40);
+m(2, 1) offset(r = -10.01) shape1(50);
+m(2, 2) offset(r = -1) shape2();
 
-offset(delta = -5) shape1(2, 1);
-shape1(0, -1);
-offset(delta = 5) shape1(1, -1);
+m(3, 0) offset(delta = 4) shape1();
+m(3, 1) offset(delta = 1) shape1();
+m(3, 2) offset(delta = 5) shape2();
+
+m(4, 0) offset(delta = -2) shape1(30);
+m(4, 1) offset(delta = -5) shape1(40);
+m(4, 2) offset(delta = -1) shape2();
+
+m(5, 0) offset(delta = 4, chamfer = true) shape1();
+m(5, 1) offset(delta = 1, chamfer = true) shape1();
+m(5, 2) offset(delta = 5, chamfer = true) shape2();
+
+m(6, 0) offset(delta = -2, chamfer = true) shape1(30);
+m(6, 1) offset(delta = -5, chamfer = true) shape1(40);
+m(6, 2) offset(delta = -1, chamfer = true) shape2();
 
 // Bug with fragment calculateion with delta < 1 due to abs() instead of std::abs()
-translate([-50,-50]) scale([25,25,1])
-	offset(delta = 0.9, join_type="round") square(.1);
+m(-2, 1) scale([30, 30]) offset(r = 0.8) square(1);
 
 // Malformed offsets
 offset();

tests/regression/dumptest-examples/offset-expected.csg

@@ -1,7 +1,7 @@
 group() {
 	group();
 	linear_extrude(height = 20, center = false, convexity = 1, scale = [0.5, 0.5], $fn = 40, $fa = 12, $fs = 2) {
-		offset(delta = 10, join_type = "round", $fn = 40, $fa = 12, $fs = 2) {
+		offset(r = 10, $fn = 40, $fa = 12, $fs = 2) {
 			square(size = [50, 50], center = true);
 		}
 	}
@@ -9,12 +9,12 @@ group() {
 		linear_extrude(height = 20, center = false, convexity = 1, scale = [1, 1], $fn = 40, $fa = 12, $fs = 2) {
 			group() {
 				difference() {
-					offset(delta = 1, join_type = "miter", miter_limit = 2, $fn = 40, $fa = 12, $fs = 2) {
+					offset(r = 1, $fn = 40, $fa = 12, $fs = 2) {
 						group() {
 							circle($fn = 40, $fa = 12, $fs = 2, r = 15);
 						}
 					}
-					offset(delta = -1, join_type = "miter", miter_limit = 2, $fn = 40, $fa = 12, $fs = 2) {
+					offset(r = -1, $fn = 40, $fa = 12, $fs = 2) {
 						group() {
 							circle($fn = 40, $fa = 12, $fs = 2, r = 15);
 						}

tests/regression/dumptest/allmodules-expected.csg

@@ -39,6 +39,6 @@ group() {
 	multmatrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]);
 	multmatrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]);
 	color([-1, -1, -1, 1]);
-	offset(delta = 1, join_type = "miter", miter_limit = 2, $fn = 0, $fa = 12, $fs = 2);
+	offset(r = 1, $fn = 0, $fa = 12, $fs = 2);
 	text(text = "", size = 10, spacing = 1, font = "", direction = "ltr", language = "en", script = "latin", halign = "left", valign = "baseline", $fn = 0, $fa = 12, $fs = 2);
 }

tests/regression/dumptest/offset-tests-expected.csg

@@ -1,144 +1,311 @@
 group() {
-	offset(delta = -1, join_type = "miter", miter_limit = 2, $fn = 0, $fa = 12, $fs = 2) {
-		group() {
-			multmatrix([[1, 0, 0, -50], [0, 1, 0, 100], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				polygon(points = [[-15, 80], [15, 80], [0, -15], [-8, 60], [8, 60], [0, 5]], paths = [[0, 1, 2], [3, 4, 5]], convexity = 1);
-			}
-		}
-	}
 	group() {
-		multmatrix([[1, 0, 0, 0], [0, 1, 0, 100], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-			polygon(points = [[-15, 80], [15, 80], [0, -15], [-8, 60], [8, 60], [0, 5]], paths = [[0, 1, 2], [3, 4, 5]], convexity = 1);
-		}
-	}
-	offset(delta = 1, join_type = "miter", miter_limit = 2, $fn = 0, $fa = 12, $fs = 2) {
-		group() {
-			multmatrix([[1, 0, 0, 50], [0, 1, 0, 100], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				polygon(points = [[-15, 80], [15, 80], [0, -15], [-8, 60], [8, 60], [0, 5]], paths = [[0, 1, 2], [3, 4, 5]], convexity = 1);
-			}
-		}
-	}
-	offset(delta = -1, join_type = "miter", miter_limit = 10, $fn = 0, $fa = 12, $fs = 2) {
-		group() {
-			multmatrix([[1, 0, 0, 100], [0, 1, 0, 100], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				polygon(points = [[-15, 80], [15, 80], [0, -15], [-8, 60], [8, 60], [0, 5]], paths = [[0, 1, 2], [3, 4, 5]], convexity = 1);
-			}
-		}
-	}
-	offset(delta = 1, join_type = "miter", miter_limit = 10, $fn = 0, $fa = 12, $fs = 2) {
-		group() {
-			multmatrix([[1, 0, 0, 150], [0, 1, 0, 100], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				polygon(points = [[-15, 80], [15, 80], [0, -15], [-8, 60], [8, 60], [0, 5]], paths = [[0, 1, 2], [3, 4, 5]], convexity = 1);
-			}
-		}
-	}
-	offset(delta = -1, join_type = "bevel", $fn = 0, $fa = 12, $fs = 2) {
-		group() {
-			multmatrix([[1, 0, 0, 100], [0, 1, 0, -50], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				polygon(points = [[-15, 80], [15, 80], [0, -15], [-8, 60], [8, 60], [0, 5]], paths = [[0, 1, 2], [3, 4, 5]], convexity = 1);
-			}
-		}
-	}
-	offset(delta = 1, join_type = "bevel", $fn = 0, $fa = 12, $fs = 2) {
-		group() {
-			multmatrix([[1, 0, 0, 150], [0, 1, 0, -50], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				polygon(points = [[-15, 80], [15, 80], [0, -15], [-8, 60], [8, 60], [0, 5]], paths = [[0, 1, 2], [3, 4, 5]], convexity = 1);
-			}
-		}
-	}
-	offset(delta = -5, join_type = "round", $fn = 0, $fa = 12, $fs = 2) {
-		group() {
-			multmatrix([[1, 0, 0, -50], [0, 1, 0, 50], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				difference() {
-					square(size = [30, 30], center = true);
-					square(size = [8, 8], center = true);
+		multmatrix([[1, 0, 0, -60], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				group() {
+					difference() {
+						square(size = [20, 20], center = true);
+						square(size = [10, 10], center = true);
+					}
 				}
 			}
 		}
 	}
 	group() {
-		multmatrix([[1, 0, 0, 0], [0, 1, 0, 50], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-			difference() {
-				square(size = [30, 30], center = true);
-				square(size = [8, 8], center = true);
-			}
-		}
-	}
-	offset(delta = 5, join_type = "round", $fn = 0, $fa = 12, $fs = 2) {
-		group() {
-			multmatrix([[1, 0, 0, 50], [0, 1, 0, 50], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				difference() {
-					square(size = [30, 30], center = true);
-					square(size = [8, 8], center = true);
-				}
-			}
-		}
-	}
-	offset(delta = -4, join_type = "miter", miter_limit = 2, $fn = 0, $fa = 12, $fs = 2) {
-		group() {
-			multmatrix([[1, 0, 0, -50], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				difference() {
-					square(size = [30, 30], center = true);
-					square(size = [8, 8], center = true);
+		multmatrix([[1, 0, 0, -60], [0, 1, 0, 120], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				group() {
+					polygon(points = [[-15, 80], [15, 80], [0, -15], [-8, 60], [8, 60], [0, 5]], paths = [[0, 1, 2], [3, 4, 5]], convexity = 1);
 				}
 			}
 		}
 	}
 	group() {
 		multmatrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-			difference() {
-				square(size = [30, 30], center = true);
-				square(size = [8, 8], center = true);
-			}
-		}
-	}
-	offset(delta = 4, join_type = "miter", miter_limit = 2, $fn = 0, $fa = 12, $fs = 2) {
-		group() {
-			multmatrix([[1, 0, 0, 50], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				difference() {
-					square(size = [30, 30], center = true);
-					square(size = [8, 8], center = true);
-				}
-			}
-		}
-	}
-	offset(delta = -5, join_type = "miter", miter_limit = 2, $fn = 0, $fa = 12, $fs = 2) {
-		group() {
-			multmatrix([[1, 0, 0, 100], [0, 1, 0, 50], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				difference() {
-					square(size = [30, 30], center = true);
-					square(size = [8, 8], center = true);
+			group() {
+				offset(r = 1, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						difference() {
+							square(size = [20, 20], center = true);
+							square(size = [10, 10], center = true);
+						}
+					}
 				}
 			}
 		}
 	}
 	group() {
-		multmatrix([[1, 0, 0, 0], [0, 1, 0, -50], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-			difference() {
-				square(size = [30, 30], center = true);
-				square(size = [8, 8], center = true);
-			}
-		}
-	}
-	offset(delta = 5, join_type = "miter", miter_limit = 2, $fn = 0, $fa = 12, $fs = 2) {
-		group() {
-			multmatrix([[1, 0, 0, 50], [0, 1, 0, -50], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				difference() {
-					square(size = [30, 30], center = true);
-					square(size = [8, 8], center = true);
+		multmatrix([[1, 0, 0, 0], [0, 1, 0, 60], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(r = 5, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						difference() {
+							square(size = [20, 20], center = true);
+							square(size = [10, 10], center = true);
+						}
+					}
 				}
 			}
 		}
 	}
-	multmatrix([[1, 0, 0, -50], [0, 1, 0, -50], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-		multmatrix([[25, 0, 0, 0], [0, 25, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-			offset(delta = 0.9, join_type = "round", $fn = 0, $fa = 12, $fs = 2) {
-				square(size = [0.1, 0.1], center = false);
+	group() {
+		multmatrix([[1, 0, 0, 0], [0, 1, 0, 120], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(r = 5, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						polygon(points = [[-15, 80], [15, 80], [0, -15], [-8, 60], [8, 60], [0, 5]], paths = [[0, 1, 2], [3, 4, 5]], convexity = 1);
+					}
+				}
 			}
 		}
 	}
-	offset(delta = 1, join_type = "miter", miter_limit = 2, $fn = 0, $fa = 12, $fs = 2);
-	offset(delta = 1, join_type = "miter", miter_limit = 2, $fn = 0, $fa = 12, $fs = 2) {
+	group() {
+		multmatrix([[1, 0, 0, 60], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(r = 1, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						difference() {
+							square(size = [30, 30], center = true);
+							square(size = [10, 10], center = true);
+						}
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 60], [0, 1, 0, 60], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(r = 5, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						difference() {
+							square(size = [30, 30], center = true);
+							square(size = [10, 10], center = true);
+						}
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 60], [0, 1, 0, 120], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(r = 5, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						polygon(points = [[-15, 80], [15, 80], [0, -15], [-8, 60], [8, 60], [0, 5]], paths = [[0, 1, 2], [3, 4, 5]], convexity = 1);
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 120], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(r = -5, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						difference() {
+							square(size = [40, 40], center = true);
+							square(size = [10, 10], center = true);
+						}
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 120], [0, 1, 0, 60], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(r = -10.01, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						difference() {
+							square(size = [50, 50], center = true);
+							square(size = [10, 10], center = true);
+						}
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 120], [0, 1, 0, 120], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(r = -1, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						polygon(points = [[-15, 80], [15, 80], [0, -15], [-8, 60], [8, 60], [0, 5]], paths = [[0, 1, 2], [3, 4, 5]], convexity = 1);
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 180], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(delta = 4, chamfer = false, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						difference() {
+							square(size = [20, 20], center = true);
+							square(size = [10, 10], center = true);
+						}
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 180], [0, 1, 0, 60], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(delta = 1, chamfer = false, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						difference() {
+							square(size = [20, 20], center = true);
+							square(size = [10, 10], center = true);
+						}
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 180], [0, 1, 0, 120], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(delta = 5, chamfer = false, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						polygon(points = [[-15, 80], [15, 80], [0, -15], [-8, 60], [8, 60], [0, 5]], paths = [[0, 1, 2], [3, 4, 5]], convexity = 1);
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 240], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(delta = -2, chamfer = false, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						difference() {
+							square(size = [30, 30], center = true);
+							square(size = [10, 10], center = true);
+						}
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 240], [0, 1, 0, 60], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(delta = -5, chamfer = false, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						difference() {
+							square(size = [40, 40], center = true);
+							square(size = [10, 10], center = true);
+						}
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 240], [0, 1, 0, 120], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(delta = -1, chamfer = false, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						polygon(points = [[-15, 80], [15, 80], [0, -15], [-8, 60], [8, 60], [0, 5]], paths = [[0, 1, 2], [3, 4, 5]], convexity = 1);
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 300], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(delta = 4, chamfer = true, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						difference() {
+							square(size = [20, 20], center = true);
+							square(size = [10, 10], center = true);
+						}
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 300], [0, 1, 0, 60], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(delta = 1, chamfer = true, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						difference() {
+							square(size = [20, 20], center = true);
+							square(size = [10, 10], center = true);
+						}
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 300], [0, 1, 0, 120], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(delta = 5, chamfer = true, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						polygon(points = [[-15, 80], [15, 80], [0, -15], [-8, 60], [8, 60], [0, 5]], paths = [[0, 1, 2], [3, 4, 5]], convexity = 1);
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 360], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(delta = -2, chamfer = true, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						difference() {
+							square(size = [30, 30], center = true);
+							square(size = [10, 10], center = true);
+						}
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 360], [0, 1, 0, 60], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(delta = -5, chamfer = true, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						difference() {
+							square(size = [40, 40], center = true);
+							square(size = [10, 10], center = true);
+						}
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, 360], [0, 1, 0, 120], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				offset(delta = -1, chamfer = true, $fn = 0, $fa = 12, $fs = 2) {
+					group() {
+						polygon(points = [[-15, 80], [15, 80], [0, -15], [-8, 60], [8, 60], [0, 5]], paths = [[0, 1, 2], [3, 4, 5]], convexity = 1);
+					}
+				}
+			}
+		}
+	}
+	group() {
+		multmatrix([[1, 0, 0, -120], [0, 1, 0, 60], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+			group() {
+				multmatrix([[30, 0, 0, 0], [0, 30, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+					offset(r = 0.8, $fn = 0, $fa = 12, $fs = 2) {
+						square(size = [1, 1], center = false);
+					}
+				}
+			}
+		}
+	}
+	offset(r = 1, $fn = 0, $fa = 12, $fs = 2);
+	offset(r = 1, $fn = 0, $fa = 12, $fs = 2) {
 		square(size = [0, 0], center = false);
 	}
 }