Explode/Combine in terms of visible elements

When generating a complex pad, this allows the user to combine with a
rotated pad and explode rotated pads without needing to rotate elements
to 0 orientation first.

Fixes: lp:1808137
* https://bugs.launchpad.net/kicad/+bug/1808137

pcbnew/class_pad.h

@@ -116,6 +116,13 @@ public:
      */
     void Move( wxPoint aMoveVector );
 
+    /**
+     * Rotates the primitive about a point
+     * @param aRotCentre center of rotation
+     * @param aAngle angle in tenths of degree
+     */
+    void Rotate( const wxPoint& aRotCentre, double aAngle );
+
     /** Export the PAD_CS_PRIMITIVE parameters to a DRAWSEGMENT
      * useful to draw a primitive shape
      * @param aTarget is the DRAWSEGMENT to initialize

pcbnew/pad_custom_shape_functions.cpp

@@ -34,6 +34,7 @@
 
 #include <bezier_curves.h>
 #include <class_board.h>
+#include <class_board_item.h>
 #include <class_drawsegment.h>
 #include <class_edge_mod.h>
 #include <class_pad.h>
@@ -88,6 +89,42 @@ void PAD_CS_PRIMITIVE::Move( wxPoint aMoveVector )
 }
 
 
+void PAD_CS_PRIMITIVE::Rotate( const wxPoint& aRotCentre, double aAngle )
+{
+    switch( m_Shape )
+    {
+    case S_ARC:
+    case S_SEGMENT:
+    case S_CIRCLE:
+        // these can all be done by just rotating the start and end points
+        RotatePoint( &m_Start, aRotCentre, aAngle );
+        RotatePoint( &m_End, aRotCentre, aAngle );
+        break;
+
+    case S_POLYGON:
+        for( auto& pt : m_Poly )
+            RotatePoint( &pt, aRotCentre, aAngle );
+
+        break;
+
+    case S_CURVE:
+        RotatePoint( &m_Start, aRotCentre, aAngle );
+        RotatePoint( &m_End, aRotCentre, aAngle );
+        RotatePoint( &m_Ctrl1, aRotCentre, aAngle );
+        RotatePoint( &m_Ctrl2, aRotCentre, aAngle );
+
+        break;
+
+    case S_RECT:
+    default:
+        // un-handled edge transform
+        wxASSERT_MSG( false, wxT( "PAD_CS_PRIMITIVE::Rotate not implemented for "
+                                     + BOARD_ITEM::ShowShape( m_Shape ) ) );
+        break;
+    }
+}
+
+
 /*
  * Has meaning only for free shape pads.
  * add a free shape to the shape list.

pcbnew/tools/drawing_tool.cpp

@@ -485,6 +485,8 @@ int DRAWING_TOOL::DrawDimension( const TOOL_EVENT& aEvent )
     int step = SET_ORIGIN;
 
     // Prime the pump
+    m_toolMgr->RunAction( ACTIONS::refreshPreview );
+
     if( aEvent.HasPosition() )
         m_toolMgr->RunAction( ACTIONS::cursorClick );
 
@@ -891,6 +893,8 @@ bool DRAWING_TOOL::drawSegment( int aShape, DRAWSEGMENT*& aGraphic, OPT<VECTOR2D
     VECTOR2I cursorPos = m_controls->GetMousePosition();
 
     // Prime the pump
+    m_toolMgr->RunAction( ACTIONS::refreshPreview );
+
     if( aStartingPoint )
         m_toolMgr->RunAction( ACTIONS::cursorClick );
 
@@ -1152,6 +1156,8 @@ bool DRAWING_TOOL::drawArc( DRAWSEGMENT*& aGraphic, bool aImmediateMode )
     bool cancelled = false;
 
     // Prime the pump
+    m_toolMgr->RunAction( ACTIONS::refreshPreview );
+
     if( aImmediateMode )
         m_toolMgr->RunAction( ACTIONS::cursorClick );
 

pcbnew/tools/footprint_editor_tools.cpp

@@ -350,6 +350,7 @@ int MODULE_EDITOR_TOOLS::ExplodePadToShapes( const TOOL_EVENT& aEvent )
         // Fix an arbitray draw layer for this EDGE_MODULE
         ds->SetLayer( Dwgs_User ); //pad->GetLayer() );
         ds->Move( anchor );
+        ds->Rotate( anchor, pad->GetOrientation() );
 
         commit.Add( ds );
     }
@@ -446,6 +447,8 @@ int MODULE_EDITOR_TOOLS::CreatePadFromShapes( const TOOL_EVENT& aEvent )
         return 0;
     }
 
+    double refOrientation = 0.0;
+
     if( refPad )
     {
         pad.reset( static_cast<D_PAD*>( refPad->Clone() ) );
@@ -453,9 +456,10 @@ int MODULE_EDITOR_TOOLS::CreatePadFromShapes( const TOOL_EVENT& aEvent )
         if( refPad->GetShape() == PAD_SHAPE_RECT )
             pad->SetAnchorPadShape( PAD_SHAPE_RECT );
 
-        // ignore the pad orientation and offset for the moment. Makes more trouble than it's worth.
-        pad->SetOrientation( 0 );
+        // ignore the pad offset for the moment. Makes more trouble than it's worth.
         pad->SetOffset( wxPoint( 0, 0 ) );
+        refOrientation = pad->GetOrientation();
+        pad->SetOrientation( 0.0 );
     }
     else
     {
@@ -497,14 +501,15 @@ int MODULE_EDITOR_TOOLS::CreatePadFromShapes( const TOOL_EVENT& aEvent )
     for( auto& shape : shapes )
     {
         shape.Move( wxPoint( -anchor->x, -anchor->y ) );
+        shape.Rotate( wxPoint( 0, 0 ), -refOrientation );
     }
 
-
     pad->SetPosition( wxPoint( anchor->x, anchor->y ) );
     pad->AddPrimitives( shapes );
     pad->ClearFlags();
 
     bool result = pad->MergePrimitivesAsPolygon();
+    pad->Rotate( wxPoint( anchor->x, anchor->y ), refOrientation );
 
     if( !result )
     {