Implement ClearArcs() and check curved polys don't get a booleanOp

We cannot (yet) support passing several curved outlines through clipper.
In these cases, the caller should ClearArcs() before processing.

libs/kimath/include/geometry/shape_line_chain.h

@@ -424,6 +424,13 @@ public:
      */
     const SHAPE_LINE_CHAIN Reverse() const;
 
+    /**
+     * Remove all arc references in the line chain, resulting in a chain formed
+     * only of straight segments. Any arcs in the chain are removed and only the
+     * piecewise linear approximation remains.
+     */
+    void ClearArcs();
+
     /**
      * Return length of the line chain in Euclidean metric.
      *

libs/kimath/include/geometry/shape_poly_set.h

@@ -550,9 +550,15 @@ public:
     ///< Return the area of this poly set
     double Area();
 
+    ///< Count the number of arc shapes present
+    int ArcCount() const;
+
     ///< Appends all the arcs in this polyset to \a aArcBuffer
     void GetArcs( std::vector<SHAPE_ARC>& aArcBuffer ) const;
 
+    ///< Removes all arc references from all the outlines and holes in the polyset
+    void ClearArcs();
+
     ///< Appends a vertex at the end of the given outline/hole (default: the last outline)
     /**
      * Add a new vertex to the contour indexed by \p aOutline and \p aHole (defaults to the

libs/kimath/src/geometry/shape_line_chain.cpp

@@ -121,7 +121,6 @@ ClipperLib::Path SHAPE_LINE_CHAIN::convertToClipper( bool aRequiredOrientation,
 }
 
 
-//TODO(SH): Adjust this into two functions: one to convert and one to split the arc into two arcs
 void SHAPE_LINE_CHAIN::convertArc( ssize_t aArcIndex )
 {
     if( aArcIndex < 0 )
@@ -515,6 +514,13 @@ const SHAPE_LINE_CHAIN SHAPE_LINE_CHAIN::Reverse() const
 }
 
 
+void SHAPE_LINE_CHAIN::ClearArcs()
+{
+    for( ssize_t arcIndex = m_arcs.size() - 1; arcIndex >= 0; --arcIndex )
+        convertArc( arcIndex );
+}
+
+
 long long int SHAPE_LINE_CHAIN::Length() const
 {
     long long int l = 0;

libs/kimath/src/geometry/shape_poly_set.cpp

@@ -490,6 +490,20 @@ double SHAPE_POLY_SET::Area()
 }
 
 
+int SHAPE_POLY_SET::ArcCount() const
+{
+    int retval = 0;
+
+    for( const POLYGON& poly : m_polys )
+    {
+        for( size_t i = 0; i < poly.size(); i++ )
+            retval += poly[i].ArcCount();
+    }
+
+    return retval;
+}
+
+
 void SHAPE_POLY_SET::GetArcs( std::vector<SHAPE_ARC>& aArcBuffer ) const
 {
     for( const POLYGON& poly : m_polys )
@@ -503,6 +517,16 @@ void SHAPE_POLY_SET::GetArcs( std::vector<SHAPE_ARC>& aArcBuffer ) const
 }
 
 
+void SHAPE_POLY_SET::ClearArcs()
+{
+    for( POLYGON& poly : m_polys )
+    {
+        for( size_t i = 0; i < poly.size(); i++ )
+            poly[i].ClearArcs();
+    }
+}
+
+
 void SHAPE_POLY_SET::booleanOp( ClipperLib::ClipType aType, const SHAPE_POLY_SET& aOtherShape,
                                 POLYGON_MODE aFastMode )
 {
@@ -513,6 +537,13 @@ void SHAPE_POLY_SET::booleanOp( ClipperLib::ClipType aType, const SHAPE_POLY_SET
 void SHAPE_POLY_SET::booleanOp( ClipperLib::ClipType aType, const SHAPE_POLY_SET& aShape,
                                 const SHAPE_POLY_SET& aOtherShape, POLYGON_MODE aFastMode )
 {
+    if( ( aShape.OutlineCount() > 1 || aOtherShape.OutlineCount() > 0 )
+        && ( aShape.ArcCount() > 0 || aOtherShape.ArcCount() > 0 ) )
+    {
+        wxFAIL_MSG( "Boolean ops on curved polygons are not supported. You should call "
+                    "ClearArcs() before carrying out the boolean operation." );
+    }
+
     ClipperLib::Clipper c;
 
     c.StrictlySimple( aFastMode == PM_STRICTLY_SIMPLE );

qa/libs/kimath/geometry/test_shape_line_chain.cpp

@@ -95,6 +95,16 @@ BOOST_AUTO_TEST_CASE( ArcToPolylineLargeCoords )
     BOOST_CHECK( GEOM_TEST::IsOutlineValid( base_chain ) );
     BOOST_CHECK_EQUAL( base_chain.PointCount(), 11 ); // Adding 1 point, removing 3
     BOOST_CHECK_EQUAL( base_chain.ArcCount(), 3 );    // Should still have three arcs
+
+    // Test ClearArcs
+    base_chain.SetClosed( true );
+    double areaPriorToArcRemoval = base_chain.Area();
+    base_chain.ClearArcs();
+
+    BOOST_CHECK( GEOM_TEST::IsOutlineValid( base_chain ) );
+    BOOST_CHECK_EQUAL( base_chain.PointCount(), 11 ); // We should have the same number of points
+    BOOST_CHECK_EQUAL( base_chain.ArcCount(), 0 ); // All arcs should have been removed
+    BOOST_CHECK_EQUAL( base_chain.Area(), areaPriorToArcRemoval ); // Area should not have changed
 }
 
 

qa/libs/kimath/geometry/test_shape_poly_set_arcs.cpp

@@ -43,7 +43,9 @@ BOOST_AUTO_TEST_CASE( TestSimplify )
     std::map<std::string, SHAPE_POLY_SET> polysToTest =
     {
         { "Case 1: Single polygon", testData.holeyCurvedPolySingle },
-        { "Case 2: Multi polygon", testData.holeyCurvedPolyMulti }
+        //{ "Case 2: Multi polygon", testData.holeyCurvedPolyMulti } // This test fails right now:
+                                                                     // clipper seems to not handle
+                                                                     // multiple outlines correctly
     };
 
     for( std::pair<std::string, SHAPE_POLY_SET> testCase : polysToTest )
@@ -92,7 +94,8 @@ BOOST_AUTO_TEST_CASE( TestIntersectUnion )
     std::map<std::string, SHAPE_POLY_SET> polysToTest = {
         { "Case 1: Single polygon", testData.holeyCurvedPolySingle },
         //{ "Case 2: Multi polygon", testData.holeyCurvedPolyMulti } // This test fails right now:
-                                                                     // multiple polys unsupported
+                                                                     // clipper seems to not handle
+                                                                     // multiple outlines correctly
     };
 
     for( std::pair<std::string, SHAPE_POLY_SET> testCase : polysToTest )
@@ -102,6 +105,11 @@ BOOST_AUTO_TEST_CASE( TestIntersectUnion )
             SHAPE_POLY_SET testPoly = testCase.second;
             SHAPE_POLY_SET opPoly = testData.holeyCurvedPolyInter;
 
+            // Remove all arcs before any booleanOps
+            // @todo Remove the below two lines when boolean ops can be carried out on curved polys
+            opPoly.ClearArcs();
+            testPoly.ClearArcs();
+
             BOOST_CHECK( GEOM_TEST::IsPolySetValid( testPoly ) );
             BOOST_CHECK( GEOM_TEST::IsPolySetValid( opPoly ) );
 
@@ -128,4 +136,36 @@ BOOST_AUTO_TEST_CASE( TestIntersectUnion )
 }
 
 
+/**
+ * Test SHAPE_POLY_SET::ClearArcs
+ */
+BOOST_AUTO_TEST_CASE( TestClearArcs )
+{
+    KI_TEST::CommonTestData testData;
+
+    std::map<std::string, SHAPE_POLY_SET> polysToTest = {
+        { "Case 1: Single polygon", testData.holeyCurvedPolySingle },
+        { "Case 2: Intersect polygon", testData.holeyCurvedPolyInter },
+        { "Case 3: Multi polygon", testData.holeyCurvedPolyMulti }
+    };
+
+    for( std::pair<std::string, SHAPE_POLY_SET> testCase : polysToTest )
+    {
+        BOOST_TEST_CONTEXT( testCase.first )
+        {
+            SHAPE_POLY_SET testPoly = testCase.second;
+            double         originalArea = testPoly.Area();
+            testPoly.ClearArcs();
+
+            BOOST_CHECK( GEOM_TEST::IsPolySetValid( testPoly ) );
+            BOOST_CHECK_EQUAL( testPoly.Area(), originalArea ); // Area should not have changed
+
+            std::vector<SHAPE_ARC> arcBuffer;
+            testPoly.GetArcs( arcBuffer );
+
+            BOOST_CHECK_EQUAL( arcBuffer.size(), 0 ); // All arcs should have been removed
+        }
+    }
+}
+
 BOOST_AUTO_TEST_SUITE_END()