Allow SHAPE_LINE_CHAIN and SHAPE_ARC to be mirrored using a SEG

libs/kimath/include/geometry/seg.h

@@ -180,6 +180,13 @@ public:
       */
     const VECTOR2I NearestPoint( const SEG &aSeg ) const;
 
+    /**
+      * Reflect a point using this segment as axis.
+      *
+      * @return the reflected point
+      */
+    const VECTOR2I ReflectPoint( const VECTOR2I& aP ) const;
+
     /**
      * Compute intersection point of segment (this) with segment \a aSeg.
      *
@@ -448,6 +455,24 @@ inline const VECTOR2I SEG::NearestPoint( const VECTOR2I& aP ) const
     return A + VECTOR2I( xp, yp );
 }
 
+inline const VECTOR2I SEG::ReflectPoint( const VECTOR2I& aP ) const
+{
+    VECTOR2I                d = B - A;
+    VECTOR2I::extended_type l_squared = d.Dot( d );
+    VECTOR2I::extended_type t = d.Dot( aP - A );
+    VECTOR2I                c;
+
+    if( !l_squared )
+        c = aP;
+    else
+    {
+        c.x = A.x + rescale( t, static_cast<VECTOR2I::extended_type>( d.x ), l_squared );
+        c.y = A.y + rescale( t, static_cast<VECTOR2I::extended_type>( d.y ), l_squared );
+    }
+
+    return 2 * c - aP;
+}
+
 inline std::ostream& operator<<( std::ostream& aStream, const SEG& aSeg )
 {
     aStream << "[ " << aSeg.A << " - " << aSeg.B << " ]";

libs/kimath/include/geometry/shape_arc.h

@@ -131,6 +131,8 @@ public:
 
     void Mirror( bool aX = true, bool aY = false, const VECTOR2I& aVector = { 0, 0 } );
 
+    void Mirror( const SEG& axis );
+
     void Reverse();
 
     SHAPE_ARC Reversed() const;

libs/kimath/include/geometry/shape_line_chain.h

@@ -708,6 +708,12 @@ public:
      */
     void Mirror( bool aX = true, bool aY = false, const VECTOR2I& aRef = { 0, 0 } );
 
+    /**
+     * Mirrors the line points using an given axis
+     * @param axis Axis on which to mirror
+     */
+    void Mirror( const SEG& axis );
+
     /**
      * Function Rotate
      * rotates all vertices by a given angle

libs/kimath/src/geometry/shape_arc.cpp

@@ -494,6 +494,16 @@ void SHAPE_ARC::Mirror( bool aX, bool aY, const VECTOR2I& aVector )
 }
 
 
+void SHAPE_ARC::Mirror( const SEG& axis )
+{
+    m_start = axis.ReflectPoint( m_start );
+    m_end = axis.ReflectPoint( m_end );
+    m_mid = axis.ReflectPoint( m_mid );
+
+    update_bbox();
+}
+
+
 void SHAPE_ARC::Reverse()
 {
     std::swap( m_start, m_end );

libs/kimath/src/geometry/shape_line_chain.cpp

@@ -256,6 +256,16 @@ void SHAPE_LINE_CHAIN::Mirror( bool aX, bool aY, const VECTOR2I& aRef )
 }
 
 
+void SHAPE_LINE_CHAIN::Mirror( const SEG& axis )
+{
+    for( auto& pt : m_points )
+        pt = axis.ReflectPoint( pt );
+
+    for( auto& arc : m_arcs )
+        arc.Mirror( axis );
+}
+
+
 void SHAPE_LINE_CHAIN::Replace( int aStartIndex, int aEndIndex, const VECTOR2I& aP )
 {
     if( aEndIndex < 0 )

pcbnew/router/pns_meander.cpp

@@ -237,25 +237,6 @@ SHAPE_LINE_CHAIN MEANDER_SHAPE::makeMiterShape( VECTOR2D aP, VECTOR2D aDir, bool
 }
 
 
-VECTOR2I MEANDER_SHAPE::reflect( VECTOR2I p, const SEG& line )
-{
-    typedef int64_t ecoord;
-    VECTOR2I d = line.B - line.A;
-    ecoord l_squared = d.Dot( d );
-    ecoord t = d.Dot( p - line.A );
-    VECTOR2I c, rv;
-
-    if( !l_squared )
-        c = p;
-    else {
-        c.x = line.A.x + rescale( t, (ecoord) d.x, l_squared );
-        c.y = line.A.y + rescale( t, (ecoord) d.y, l_squared );
-    }
-
-    return 2 * c - p;
-}
-
-
 void MEANDER_SHAPE::start( SHAPE_LINE_CHAIN* aTarget, const VECTOR2D& aWhere, const VECTOR2D& aDir )
 {
     m_currentTarget = aTarget;
@@ -392,8 +373,7 @@ SHAPE_LINE_CHAIN MEANDER_SHAPE::genMeanderShape( VECTOR2D aP, VECTOR2D aDir,
     {
         SEG axis( aP, aP + aDir );
 
-        for( int i = 0; i < lc.PointCount(); i++ )
-            lc.SetPoint( i, reflect( lc.CPoint( i ), axis ) );
+        lc.Mirror( axis );
     }
 
     return lc;

pcbnew/router/pns_meander.h

@@ -297,9 +297,6 @@ private:
     ///< Generate a 90-degree circular arc.
     SHAPE_LINE_CHAIN makeMiterShape( VECTOR2D aP, VECTOR2D aDir, bool aSide );
 
-    ///< Reflect a point onto other side of a given segment.
-    VECTOR2I reflect( VECTOR2I aP, const SEG& aLine );
-
     ///< Produce a meander shape of given type.
     SHAPE_LINE_CHAIN genMeanderShape( VECTOR2D aP, VECTOR2D aDir, bool aSide, MEANDER_TYPE aType,
                                       int aAmpl, int aBaselineOffset = 0 );