STEP export: handle polygons with arcs (and convert arcs to segments).

Fixes #11389
https://gitlab.com/kicad/code/kicad/issues/11389

utils/kicad2step/pcb/kicadcurve.cpp

@@ -2,6 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2016 Cirilo Bernardo <cirilo.bernardo@gmail.com>
+ * Copyright (C) 2022 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -53,6 +54,7 @@ KICADCURVE::~KICADCURVE()
 }
 
 #include <sexpr/sexpr_parser.h>
+#include <geometry/shape_line_chain.h>
 
 bool KICADCURVE::Read( SEXPR::SEXPR* aEntry, CURVE_TYPE aCurveType )
 {
@@ -60,7 +62,7 @@ bool KICADCURVE::Read( SEXPR::SEXPR* aEntry, CURVE_TYPE aCurveType )
         && CURVE_CIRCLE != aCurveType && CURVE_BEZIER != aCurveType
         && CURVE_POLYGON != aCurveType )
     {
-        wxLogMessage( wxT( "* Unsupported curve type: %d\n" ), aCurveType );
+        wxLogMessage( "* Unsupported curve type: %d\n", aCurveType );
         return false;
     }
 
@@ -74,7 +76,7 @@ bool KICADCURVE::Read( SEXPR::SEXPR* aEntry, CURVE_TYPE aCurveType )
         || ( CURVE_BEZIER == aCurveType && nchild < 5 )
         || ( CURVE_POLYGON == aCurveType && nchild < 5 ) )
     {
-        wxLogMessage( wxT( "* bad curve data; not enough parameters\n" ) );
+        wxLogMessage( "* bad curve data; not enough parameters\n" );
         return false;
     }
 
@@ -110,6 +112,8 @@ bool KICADCURVE::Read( SEXPR::SEXPR* aEntry, CURVE_TYPE aCurveType )
                 SEXPR::SEXPR* sub_child = ( *list )[ii];
                 text = sub_child->GetChild( 0 )->GetSymbol();
 
+                // inside pts list, parmeters are xy point coord
+                // or a arc (start, middle, end) points
                 if( text == "xy" )
                 {
                     DOUBLET coord;
@@ -132,6 +136,49 @@ bool KICADCURVE::Read( SEXPR::SEXPR* aEntry, CURVE_TYPE aCurveType )
                     else
                         m_poly.push_back( coord );
                 }
+                else if( text == "arc" )
+                {
+                    int arc_child = sub_child->GetNumberOfChildren();
+                    DOUBLET arc_start, arc_middle, arc_end;
+
+                    for( int jj = 1; jj < arc_child; jj++ )
+                    {
+                        SEXPR::SEXPR* curr_child = sub_child->GetChild( jj );
+                        text = curr_child->GetChild( 0 )->GetSymbol();
+
+                        if( text == "start" )
+                        {
+                             if( !Get2DCoordinate( curr_child, arc_start ) )
+                                return false;
+                        }
+                        else if( text == "end" )
+                        {
+                            if( !Get2DCoordinate( curr_child, arc_end ) )
+                                return false;
+                        }
+                        else if( text == "mid" )
+                        {
+                            if( !Get2DCoordinate( curr_child, arc_middle ) )
+                                return false;
+                        }
+                    }
+
+                    // To convert arc edge to segments, we are using SHAPE_ARC, but SHAPE_ARC use
+                    // integer coords. So to avoid truncations, use a scaling factor.
+                    // 1e5 is enough.
+                    const double scale = 1e5;
+                    SHAPE_ARC new_arc( VECTOR2I( arc_start.x*scale, arc_start.y*scale ),
+                                       VECTOR2I( arc_middle.x*scale, arc_middle.y*scale ),
+                                       VECTOR2I( arc_end.x*scale, arc_end.y*scale ), 0 );
+
+                    double accuracy = 0.005*scale;  // Approx accuracy is 5 microns
+                    SHAPE_LINE_CHAIN segs_from_arc = new_arc.ConvertToPolyline( accuracy );
+
+                    // Add segments to STEP polygon
+                    for( int ll = 0; ll < segs_from_arc.PointCount(); ll++ )
+                        m_poly.emplace_back( segs_from_arc.CPoint(ll).x/scale,
+                                             segs_from_arc.CPoint(ll).y/scale );
+                }
             }
         }
         else if( text == "start" || text == "center" )
@@ -154,9 +201,10 @@ bool KICADCURVE::Read( SEXPR::SEXPR* aEntry, CURVE_TYPE aCurveType )
         else if( text == "angle" )
         {
             if( child->GetNumberOfChildren() < 2
-                || ( !child->GetChild( 1 )->IsDouble() && !child->GetChild( 1 )->IsInteger() ) )
+                || ( !child->GetChild( 1 )->IsDouble()
+                     && !child->GetChild( 1 )->IsInteger() ) )
             {
-                wxLogMessage( wxT( "* bad angle data\n" ) );
+                wxLogMessage( "* bad angle data\n" );
                 return false;
             }
 
@@ -175,7 +223,7 @@ bool KICADCURVE::Read( SEXPR::SEXPR* aEntry, CURVE_TYPE aCurveType )
             {
                 std::ostringstream ostr;
                 ostr << "* bad layer data: " << child->AsString();
-                wxLogMessage( wxT( "%s\n" ), ostr.str().c_str() );
+                wxLogMessage( "%s\n", ostr.str().c_str() );
                 return false;
             }
 
@@ -205,7 +253,7 @@ bool KICADCURVE::Read( SEXPR::SEXPR* aEntry, CURVE_TYPE aCurveType )
         m_end.y = new_arc.GetP0().y/scale;
         m_ep.x = new_arc.GetP1().x/scale;
         m_ep.y = new_arc.GetP1().y/scale;
-        m_angle = new_arc.GetCentralAngle().AsRadians();
+        m_angle = new_arc.GetCentralAngle() / 180.0 * M_PI;
     }
 
     return true;