From e4dd4da8182ce2a06a7709ab015dd0e541becd1a Mon Sep 17 00:00:00 2001
From: Marius Kintel <marius@kintel.net>
Date: Mon, 19 May 2014 11:49:41 -0400
Subject: [PATCH] #791 Handle twist=0 as no twist

---
 src/linearextrude.cc                          | 14 ++++++-----
 ...near_extrude-scale-zero-tests-expected.csg | 24 +++++++++----------
 .../dumptest/use-tests-expected.csg           |  4 ++--
 3 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/src/linearextrude.cc b/src/linearextrude.cc
index d2d798be..235c45ea 100644
--- a/src/linearextrude.cc
+++ b/src/linearextrude.cc
@@ -110,13 +110,15 @@ AbstractNode *LinearExtrudeModule::instantiate(const Context *ctx, const ModuleI
 
 	if (twist.type() == Value::NUMBER) {
 		node->twist = twist.toDouble();
-		if (slices.type() == Value::NUMBER) {
-			node->slices = (int)slices.toDouble();
-		} else {
-			node->slices = (int)fmax(2, fabs(Calc::get_fragments_from_r(node->height,
-					node->fn, node->fs, node->fa) * node->twist / 360));
+		if (node->twist != 0.0) {
+			if (slices.type() == Value::NUMBER) {
+				node->slices = (int)slices.toDouble();
+			} else {
+				node->slices = (int)fmax(2, fabs(Calc::get_fragments_from_r(node->height,
+																																		node->fn, node->fs, node->fa) * node->twist / 360));
+			}
+			node->has_twist = true;
 		}
-		node->has_twist = true;
 	}
 
 	if (node->filename.empty()) {
diff --git a/tests/regression/dumptest/linear_extrude-scale-zero-tests-expected.csg b/tests/regression/dumptest/linear_extrude-scale-zero-tests-expected.csg
index e4d24305..b1148d4f 100644
--- a/tests/regression/dumptest/linear_extrude-scale-zero-tests-expected.csg
+++ b/tests/regression/dumptest/linear_extrude-scale-zero-tests-expected.csg
@@ -2,7 +2,7 @@ group() {
 	multmatrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
 		group() {
 			multmatrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				linear_extrude(height = 3, center = false, convexity = 1, twist = 0, slices = 20, scale = [0, 1], $fn = 0, $fa = 12, $fs = 2) {
+				linear_extrude(height = 3, center = false, convexity = 1, scale = [0, 1], $fn = 0, $fa = 12, $fs = 2) {
 					difference() {
 						square(size = [2, 2], center = true);
 						square(size = [1, 1], center = true);
@@ -10,7 +10,7 @@ group() {
 				}
 			}
 			multmatrix([[1, 0, 0, 4], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				linear_extrude(height = 3, center = false, convexity = 1, twist = 0, slices = 20, scale = [0, 1], $fn = 0, $fa = 12, $fs = 2) {
+				linear_extrude(height = 3, center = false, convexity = 1, scale = [0, 1], $fn = 0, $fa = 12, $fs = 2) {
 					multmatrix([[1, 0, 0, 1], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
 						square(size = [1, 1], center = true);
 					}
@@ -20,7 +20,7 @@ group() {
 				}
 			}
 			multmatrix([[1, 0, 0, 8], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				linear_extrude(height = 3, center = false, convexity = 1, twist = 0, slices = 20, scale = [0, 1], $fn = 0, $fa = 12, $fs = 2) {
+				linear_extrude(height = 3, center = false, convexity = 1, scale = [0, 1], $fn = 0, $fa = 12, $fs = 2) {
 					multmatrix([[1, 0, 0, 0.5], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
 						square(size = [1, 1], center = false);
 					}
@@ -30,7 +30,7 @@ group() {
 				}
 			}
 			multmatrix([[1, 0, 0, 12], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				linear_extrude(height = 3, center = false, convexity = 1, twist = 0, slices = 20, scale = [0, 1], $fn = 0, $fa = 12, $fs = 2) {
+				linear_extrude(height = 3, center = false, convexity = 1, scale = [0, 1], $fn = 0, $fa = 12, $fs = 2) {
 					difference() {
 						square(size = [2, 2], center = true);
 						multmatrix([[1, 0, 0, -0.5], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
@@ -44,7 +44,7 @@ group() {
 	multmatrix([[1, 0, 0, 0], [0, 1, 0, 3], [0, 0, 1, 0], [0, 0, 0, 1]]) {
 		group() {
 			multmatrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				linear_extrude(height = 3, center = false, convexity = 1, twist = 0, slices = 20, scale = [1, 0], $fn = 0, $fa = 12, $fs = 2) {
+				linear_extrude(height = 3, center = false, convexity = 1, scale = [1, 0], $fn = 0, $fa = 12, $fs = 2) {
 					difference() {
 						square(size = [2, 2], center = true);
 						square(size = [1, 1], center = true);
@@ -52,7 +52,7 @@ group() {
 				}
 			}
 			multmatrix([[1, 0, 0, 4], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				linear_extrude(height = 3, center = false, convexity = 1, twist = 0, slices = 20, scale = [1, 0], $fn = 0, $fa = 12, $fs = 2) {
+				linear_extrude(height = 3, center = false, convexity = 1, scale = [1, 0], $fn = 0, $fa = 12, $fs = 2) {
 					multmatrix([[1, 0, 0, 1], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
 						square(size = [1, 1], center = true);
 					}
@@ -62,7 +62,7 @@ group() {
 				}
 			}
 			multmatrix([[1, 0, 0, 8], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				linear_extrude(height = 3, center = false, convexity = 1, twist = 0, slices = 20, scale = [1, 0], $fn = 0, $fa = 12, $fs = 2) {
+				linear_extrude(height = 3, center = false, convexity = 1, scale = [1, 0], $fn = 0, $fa = 12, $fs = 2) {
 					multmatrix([[1, 0, 0, 0.5], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
 						square(size = [1, 1], center = false);
 					}
@@ -72,7 +72,7 @@ group() {
 				}
 			}
 			multmatrix([[1, 0, 0, 12], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				linear_extrude(height = 3, center = false, convexity = 1, twist = 0, slices = 20, scale = [1, 0], $fn = 0, $fa = 12, $fs = 2) {
+				linear_extrude(height = 3, center = false, convexity = 1, scale = [1, 0], $fn = 0, $fa = 12, $fs = 2) {
 					difference() {
 						square(size = [2, 2], center = true);
 						multmatrix([[1, 0, 0, -0.5], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
@@ -86,7 +86,7 @@ group() {
 	multmatrix([[1, 0, 0, 0], [0, 1, 0, 6], [0, 0, 1, 0], [0, 0, 0, 1]]) {
 		group() {
 			multmatrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				linear_extrude(height = 3, center = false, convexity = 1, twist = 0, slices = 20, scale = [0, 0], $fn = 0, $fa = 12, $fs = 2) {
+				linear_extrude(height = 3, center = false, convexity = 1, scale = [0, 0], $fn = 0, $fa = 12, $fs = 2) {
 					difference() {
 						square(size = [2, 2], center = true);
 						square(size = [1, 1], center = true);
@@ -94,7 +94,7 @@ group() {
 				}
 			}
 			multmatrix([[1, 0, 0, 4], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				linear_extrude(height = 3, center = false, convexity = 1, twist = 0, slices = 20, scale = [0, 0], $fn = 0, $fa = 12, $fs = 2) {
+				linear_extrude(height = 3, center = false, convexity = 1, scale = [0, 0], $fn = 0, $fa = 12, $fs = 2) {
 					multmatrix([[1, 0, 0, 1], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
 						square(size = [1, 1], center = true);
 					}
@@ -104,7 +104,7 @@ group() {
 				}
 			}
 			multmatrix([[1, 0, 0, 8], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				linear_extrude(height = 3, center = false, convexity = 1, twist = 0, slices = 20, scale = [0, 0], $fn = 0, $fa = 12, $fs = 2) {
+				linear_extrude(height = 3, center = false, convexity = 1, scale = [0, 0], $fn = 0, $fa = 12, $fs = 2) {
 					multmatrix([[1, 0, 0, 0.5], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
 						square(size = [1, 1], center = false);
 					}
@@ -114,7 +114,7 @@ group() {
 				}
 			}
 			multmatrix([[1, 0, 0, 12], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
-				linear_extrude(height = 3, center = false, convexity = 1, twist = 0, slices = 20, scale = [0, 0], $fn = 0, $fa = 12, $fs = 2) {
+				linear_extrude(height = 3, center = false, convexity = 1, scale = [0, 0], $fn = 0, $fa = 12, $fs = 2) {
 					difference() {
 						square(size = [2, 2], center = true);
 						multmatrix([[1, 0, 0, -0.5], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
diff --git a/tests/regression/dumptest/use-tests-expected.csg b/tests/regression/dumptest/use-tests-expected.csg
index c47fa742..1535abe7 100644
--- a/tests/regression/dumptest/use-tests-expected.csg
+++ b/tests/regression/dumptest/use-tests-expected.csg
@@ -40,10 +40,10 @@ group() {
 			group() {
 				multmatrix([[0, 0, 1, 0], [0, 1, 0, 0], [-1, 0, 0, 0], [0, 0, 0, 1]]) {
 					union() {
-						linear_extrude(height = 1.5, center = true, convexity = 1, twist = 0, slices = 2, scale = [1, 1], $fn = 0, $fa = 12, $fs = 2) {
+						linear_extrude(height = 1.5, center = true, convexity = 1, scale = [1, 1], $fn = 0, $fa = 12, $fs = 2) {
 							circle($fn = 30, $fa = 12, $fs = 2, r = 0.3);
 						}
-						linear_extrude(height = 1.5, center = true, convexity = 1, twist = 0, slices = 2, scale = [1, 1], $fn = 0, $fa = 12, $fs = 2) {
+						linear_extrude(height = 1.5, center = true, convexity = 1, scale = [1, 1], $fn = 0, $fa = 12, $fs = 2) {
 							projection(cut = false, convexity = 0) {
 								multmatrix([[0, 0, -1, 0], [0, 1, 0, 0], [1, 0, 0, 0], [0, 0, 0, 1]]) {
 									multmatrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0.31819805153], [0, 0, 0, 1]]) {