Merge branch 'poly2_bug' of git://github.com/OskarLinde/openscad into OskarLinde-poly2_bug

src/clipper-utils.cc

@@ -42,20 +42,26 @@ namespace ClipperUtils {
 	 path before adding it to the Polygon2d.
  */
 	Polygon2d *toPolygon2d(const ClipperLib::PolyTree &poly) {
+		const double CLEANING_DISTANCE = 0.001 * CLIPPER_SCALE;
+
 		Polygon2d *result = new Polygon2d;
 		const ClipperLib::PolyNode *node = poly.GetFirst();
 		while (node) {
 			Outline2d outline;
 			outline.positive = !node->IsHole();
-			const Vector2d *lastv = NULL;
-			BOOST_FOREACH(const ClipperLib::IntPoint &ip, node->Contour) {
-				Vector2d v(1.0*ip.X/CLIPPER_SCALE, 1.0*ip.Y/CLIPPER_SCALE);
-				// Ignore too close vertices. This is to be nice to subsequent processes.
-				if (lastv && (v-*lastv).squaredNorm() < 0.001) continue;
-				outline.vertices.push_back(v);
-				lastv = &outline.vertices.back();
+
+			ClipperLib::Path cleaned_path;
+			ClipperLib::CleanPolygon(node->Contour, cleaned_path, CLEANING_DISTANCE);
+
+			// CleanPolygon can in some cases reduce the polygon down to no vertices
+			if (cleaned_path.size() >= 3)  {
+				BOOST_FOREACH(const ClipperLib::IntPoint &ip, cleaned_path) {
+					Vector2d v(1.0*ip.X/CLIPPER_SCALE, 1.0*ip.Y/CLIPPER_SCALE);
+					outline.vertices.push_back(v);
+				}
+				result->addOutline(outline);
 			}
-			result->addOutline(outline);
+
 			node = node->GetNext();
 		}
 		result->setSanitized(true);

testdata/scad/bugs/incorrect_polygon.scad

@@ -0,0 +1,16 @@
+
+$fn = 64;
+
+module inverse() difference() { square(1e6,center=true); child(); }
+module offset(d=1) minkowski() { circle(d); child(); }
+
+module s() {
+	inverse() offset(2) inverse() offset(2) union() { 
+		hull() { circle(r=4); translate([0,3]) circle(r=4); } 
+		translate([0,-3]) hull() { circle(r=1); translate([10,0]) circle(r=1); } 
+	}
+}
+difference() {
+	linear_extrude(height=3,center=true,convexity=3) s();
+	linear_extrude(height=9,center=true) circle(r=2);
+}

tests/CMakeLists.txt

@@ -863,6 +863,7 @@ list(APPEND CGALPNGTEST_FILES ${FEATURES_FILES} ${SCAD_DXF_FILES} ${EXAMPLE_FILE
 list(APPEND CGALPNGTEST_FILES ${CMAKE_SOURCE_DIR}/../testdata/scad/misc/include-tests.scad
                            ${CMAKE_SOURCE_DIR}/../testdata/scad/misc/use-tests.scad
                            ${CMAKE_SOURCE_DIR}/../testdata/scad/bugs/transform-nan-inf-tests.scad
+                           ${CMAKE_SOURCE_DIR}/../testdata/scad/bugs/incorrect_polygon.scad
                            ${CMAKE_SOURCE_DIR}/../testdata/scad/misc/localfiles-test.scad
                            ${CMAKE_SOURCE_DIR}/../testdata/scad/misc/localfiles_dir/localfiles-compatibility-test.scad
                            ${CMAKE_SOURCE_DIR}/../testdata/scad/misc/rotate-empty-bbox.scad