Fixes: lp:1696204 3D STEP export doesn't handle B.Cu rename

https://bugs.launchpad.net/kicad/+bug/1696204

utils/kicad2step/pcb/kicadmodule.cpp

@@ -35,8 +35,9 @@
 #include "oce_utils.h"
 
 
-KICADMODULE::KICADMODULE()
+KICADMODULE::KICADMODULE( KICADPCB* aParent )
 {
+    m_parent = aParent;
     m_side = LAYER_NONE;
     m_rotation = 0.0;
     m_virtual = false;
@@ -172,12 +173,12 @@ bool KICADMODULE::parseCurve( SEXPR::SEXPR* data, CURVE_TYPE aCurveType )
 bool KICADMODULE::parseLayer( SEXPR::SEXPR* data )
 {
     SEXPR::SEXPR* val = data->GetChild( 1 );
-    std::string layer;
+    std::string layername;
 
     if( val->IsSymbol() )
-        layer = val->GetSymbol();
+        layername = val->GetSymbol();
     else if( val->IsString() )
-        layer = val->GetString();
+        layername = val->GetString();
     else
     {
         std::ostringstream ostr;
@@ -187,10 +188,12 @@ bool KICADMODULE::parseLayer( SEXPR::SEXPR* data )
         return false;
     }
 
-    if( layer == "F.Cu" )
-        m_side = LAYER_TOP;
-    else if( layer == "B.Cu" )
+    int layerId = m_parent->GetLayerId( layername );
+
+    if( layerId == 31 )
         m_side = LAYER_BOTTOM;
+    else
+        m_side = LAYER_TOP;
 
     return true;
 }

utils/kicad2step/pcb/kicadmodule.h

@@ -55,6 +55,8 @@ private:
     bool parseText( SEXPR::SEXPR* data );
     bool parsePad( SEXPR::SEXPR* data );
 
+    KICADPCB* m_parent;     // The parent KICADPCB, to know layer names
+
     LAYERS      m_side;
     std::string m_refdes;
     DOUBLET     m_position;
@@ -66,7 +68,7 @@ private:
     std::vector< KICADMODEL* >  m_models;
 
 public:
-    KICADMODULE();
+    KICADMODULE( KICADPCB* aParent );
     virtual ~KICADMODULE();
 
     bool Read( SEXPR::SEXPR* aEntry );

utils/kicad2step/pcb/kicadpcb.cpp

@@ -246,6 +246,8 @@ bool KICADPCB::parsePCB( SEXPR::SEXPR* data )
                 result = result && parseGeneral( child );
             else if( symname == "setup" )
                 result = result && parseSetup( child );
+            else if( symname == "layers" )
+                result = result && parseLayers( child );
             else if( symname == "module" )
                 result = result && parseModule( child );
             else if( symname == "gr_arc" )
@@ -304,6 +306,44 @@ bool KICADPCB::parseGeneral( SEXPR::SEXPR* data )
 }
 
 
+bool KICADPCB::parseLayers( SEXPR::SEXPR* data )
+{
+    size_t nc = data->GetNumberOfChildren();
+    SEXPR::SEXPR* child = NULL;
+
+    // Read the layername and the correstponding layer id list:
+    for( size_t i = 1; i < nc; ++i )
+    {
+        child = data->GetChild( i );
+
+        if( !child->IsList() )
+        {
+            std::ostringstream ostr;
+            ostr << "* corrupt PCB file (line " << child->GetLineNumber();
+            ostr << "): '" << m_filename << "'\n";
+            wxLogMessage( "%s\n", ostr.str().c_str() );
+            return false;
+        }
+
+        m_layersNames[child->GetChild( 1 )->GetSymbol()] =
+                      child->GetChild( 0 )->GetInteger();
+    }
+
+    return true;
+}
+
+int KICADPCB::GetLayerId( std::string& aLayerName )
+{
+    int lid = -1;
+    auto item = m_layersNames.find( aLayerName );
+
+    if( item != m_layersNames.end() )
+        lid = item->second;
+
+    return lid;
+}
+
+
 bool KICADPCB::parseSetup( SEXPR::SEXPR* data )
 {
     size_t nc = data->GetNumberOfChildren();
@@ -369,7 +409,7 @@ bool KICADPCB::parseSetup( SEXPR::SEXPR* data )
 
 bool KICADPCB::parseModule( SEXPR::SEXPR* data )
 {
-    KICADMODULE* mp = new KICADMODULE();
+    KICADMODULE* mp = new KICADMODULE( this );
 
     if( !mp->Read( data ) )
     {

utils/kicad2step/pcb/kicadpcb.h

@@ -62,6 +62,8 @@ private:
     // set to TRUE if the origin was actually parsed
     bool        m_hasGridOrigin;
     bool        m_hasDrillOrigin;
+    // the names of layers in use, and the internal layer ID
+    std::map<std::string, int> m_layersNames;
 
     // PCB parameters/entities
     double                      m_thickness;
@@ -71,6 +73,7 @@ private:
     bool parsePCB( SEXPR::SEXPR* data );
     bool parseGeneral( SEXPR::SEXPR* data );
     bool parseSetup( SEXPR::SEXPR* data );
+    bool parseLayers( SEXPR::SEXPR* data );
     bool parseModule( SEXPR::SEXPR* data );
     bool parseCurve( SEXPR::SEXPR* data, CURVE_TYPE aCurveType );
 
@@ -78,6 +81,8 @@ public:
     KICADPCB();
     virtual ~KICADPCB();
 
+    int GetLayerId( std::string& aLayerName );
+
     void SetOrigin( double aXOrigin, double aYOrigin )
     {
         m_origin.x = aXOrigin;