Gerber plotter: plot round rectangle pads using a region with arcs.

Previously, the region was a usual polygon with arc approximated by segment.
Using a region with arcs is a better way because it allows CAM tools to
identify this region as a round-rect pad.

A side effect is a better shape and smaller files, however not really noticeable in fact.

common/plotters/GERBER_plotter.cpp

@@ -520,10 +520,23 @@ void GERBER_PLOTTER::Arc( const wxPoint& aCenter, double aStAngle, double aEndAn
 {
     SetCurrentLineWidth( aWidth );
 
+    // aFill is not used here.
+    plotArc( aCenter, aStAngle, aEndAngle, aRadius, false );
+}
+
+
+void GERBER_PLOTTER::plotArc( const wxPoint& aCenter, double aStAngle, double aEndAngle,
+                  int aRadius, bool aPlotInRegion )
+{
     wxPoint start, end;
     start.x = aCenter.x + KiROUND( cosdecideg( aRadius, aStAngle ) );
     start.y = aCenter.y - KiROUND( sindecideg( aRadius, aStAngle ) );
+
+    if( !aPlotInRegion )
         MoveTo( start );
+    else
+        LineTo( start );
+
     end.x = aCenter.x + KiROUND( cosdecideg( aRadius, aEndAngle ) );
     end.y = aCenter.y - KiROUND( sindecideg( aRadius, aEndAngle ) );
     DPOINT devEnd = userToDeviceCoordinates( end );
@@ -855,16 +868,14 @@ void GERBER_PLOTTER::FlashPadRect( const wxPoint& pos, const wxSize& aSize,
         }
         break;
 
-    default: // plot pad shape as polygon
+    default: // plot pad shape as Gerber region
     {
-        // XXX to do: use an aperture macro to declare the rotated pad
         wxPoint coord[4];
         // coord[0] is assumed the lower left
         // coord[1] is assumed the upper left
         // coord[2] is assumed the upper right
         // coord[3] is assumed the lower right
 
-        /* Trace the outline. */
         coord[0].x = -size.x/2;   // lower left
         coord[0].y = size.y/2;
         coord[1].x = -size.x/2;   // upper left
@@ -887,17 +898,14 @@ void GERBER_PLOTTER::FlashPadRoundRect( const wxPoint& aPadPos, const wxSize& aS
 {
     GBR_METADATA* gbr_metadata = static_cast<GBR_METADATA*>( aData );
 
-    // Currently, a Pad RoundRect is plotted as polygon.
+    if( aTraceMode != FILLED )
-    // TODO: use Aperture macro and flash it
+    {
         SHAPE_POLY_SET outline;
         TransformRoundChamferedRectToPolygon( outline, aPadPos, aSize, aOrient,
                                      aCornerRadius, 0.0, 0, GetPlotterArcHighDef() );
 
-    if( aTraceMode != FILLED )
-    {
         SetCurrentLineWidth( USE_DEFAULT_LINE_WIDTH, &gbr_metadata );
         outline.Inflate( -GetCurrentLineWidth()/2, 16 );
-    }
 
         std::vector< wxPoint > cornerList;
         // TransformRoundRectToPolygon creates only one convex polygon
@@ -910,11 +918,151 @@ void GERBER_PLOTTER::FlashPadRoundRect( const wxPoint& aPadPos, const wxSize& aS
         // Close polygon
         cornerList.push_back( cornerList[0] );
 
-    if( aTraceMode == SKETCH )
+        // plot outlines
         PlotPoly( cornerList, NO_FILL, GetCurrentLineWidth(), gbr_metadata );
-    else
-        PlotGerberRegion( cornerList, gbr_metadata );
     }
+    else
+    {
+        // A Pad RoundRect is plotted as a Gerber region.
+        // Initialize region metadata:
+        bool clearTA_AperFunction = false;     // true if a TA.AperFunction is used
+
+        if( gbr_metadata )
+        {
+            formatNetAttribute( &gbr_metadata->m_NetlistMetadata );
+            std::string attrib = gbr_metadata->m_ApertureMetadata.FormatAttribute( !m_useX2format );
+
+            if( !attrib.empty() )
+            {
+                fputs( attrib.c_str(), outputFile );
+                clearTA_AperFunction = true;
+            }
+        }
+
+        // Plot the region using arcs in corners.
+        plotRoundRectAsRegion( aPadPos, aSize, aCornerRadius, aOrient );
+
+        // Clear the TA attribute, to avoid the next item to inherit it:
+        if( clearTA_AperFunction )
+        {
+            if( m_useX2format )
+            {
+                fputs( "%TD.AperFunction*%\n", outputFile );
+            }
+            else
+            {
+                fputs( "G04 #@! TD.AperFunction*\n", outputFile );
+            }
+        }
+    }
+}
+
+
+void GERBER_PLOTTER::plotRoundRectAsRegion( const wxPoint& aRectCenter, const wxSize& aSize,
+                                            int aCornerRadius, double aOrient )
+{
+    // The region outline is generated by 4 sides and 4 90 deg arcs
+    //  1 --- 2
+    //  |  c  |
+    //  4 --- 3
+
+    // Note also in user coordinates the Y axis is from top to bottom
+    // for historical reasons.
+
+    // A helper structure to handle outlines coordinates (segments and arcs)
+    // in user coordinates
+    struct RR_EDGE
+    {
+        wxPoint m_start;
+        wxPoint m_end;
+        wxPoint m_center;
+        // in decidegrees: angle start. angle end = m_arc_angle_start+arc_angle
+        double  m_arc_angle_start;
+    };
+
+    const double arc_angle = -900.0;    // in decidegrees
+    int hsizeX = aSize.x/2;
+    int hsizeY = aSize.y/2;
+
+    RR_EDGE curr_edge;
+    std::vector<RR_EDGE> rr_outline;
+
+    // Build outline coordinates, relative to rectangle center, rotation 0:
+
+    // Top left corner 1 (and 4 to 1 left vertical side @ x=-hsizeX)
+    curr_edge.m_start.x = -hsizeX;
+    curr_edge.m_start.y = hsizeY - aCornerRadius;
+    curr_edge.m_end.x = curr_edge.m_start.x;
+    curr_edge.m_end.y = -hsizeY + aCornerRadius;
+    curr_edge.m_center.x = -hsizeX + aCornerRadius;
+    curr_edge.m_center.y = curr_edge.m_end.y;
+    curr_edge.m_arc_angle_start = aOrient + 1800.0;     // En decidegree
+
+    rr_outline.push_back( curr_edge );
+
+    // Top right corner 2 (and 1 to 2 top horizontal side @ y=-hsizeY)
+    curr_edge.m_start.x = -hsizeX + aCornerRadius;
+    curr_edge.m_start.y = -hsizeY;
+    curr_edge.m_end.x = hsizeX - aCornerRadius;
+    curr_edge.m_end.y = curr_edge.m_start.y;
+    curr_edge.m_center.x = curr_edge.m_end.x;
+    curr_edge.m_center.y = -hsizeY + aCornerRadius;
+    curr_edge.m_arc_angle_start = aOrient + 900.0;     // En decidegree
+
+    rr_outline.push_back( curr_edge );
+
+    // bottom right corner 3 (and 2 to 3 right vertical side @ x=hsizeX)
+    curr_edge.m_start.x = hsizeX;
+    curr_edge.m_start.y = -hsizeY + aCornerRadius;
+    curr_edge.m_end.x =  curr_edge.m_start.x;
+    curr_edge.m_end.y = hsizeY - aCornerRadius;
+    curr_edge.m_center.x = hsizeX - aCornerRadius;
+    curr_edge.m_center.y = curr_edge.m_end.y;
+    curr_edge.m_arc_angle_start = aOrient + 0.0;     // En decidegree
+
+    rr_outline.push_back( curr_edge );
+
+    // bottom left corner 4 (and 3 to 4 bottom horizontal side @ y=hsizeY)
+    curr_edge.m_start.x = hsizeX - aCornerRadius;
+    curr_edge.m_start.y = hsizeY;
+    curr_edge.m_end.x =  -hsizeX + aCornerRadius;
+    curr_edge.m_end.y = curr_edge.m_start.y;
+    curr_edge.m_center.x = curr_edge.m_end.x;
+    curr_edge.m_center.y = hsizeY - aCornerRadius;
+    curr_edge.m_arc_angle_start = aOrient - 900.0;     // En decidegree
+
+    rr_outline.push_back( curr_edge );
+
+    // Move relative coordinates to the actual location and rotation:
+    for( RR_EDGE& rr_edge: rr_outline )
+    {
+        RotatePoint( &rr_edge.m_start, aOrient );
+        RotatePoint( &rr_edge.m_end, aOrient );
+        RotatePoint( &rr_edge.m_center, aOrient );
+        rr_edge.m_start += aRectCenter;
+        rr_edge.m_end += aRectCenter;
+        rr_edge.m_center += aRectCenter;
+    }
+
+    fputs( "G36*\n", outputFile );      // Start region
+    fputs( "G01*\n", outputFile );      // Set linear interpolation.
+    MoveTo( rr_outline[0].m_start );    // Start point of region
+
+    for( RR_EDGE& rr_edge: rr_outline )
+    {
+        if( aCornerRadius )     // Guard: ensure we do not create arcs with radius = 0
+        {
+            // LineTo( rr_edge.m_end ); // made in plotArc()
+            plotArc( rr_edge.m_center, rr_edge.m_arc_angle_start, rr_edge.m_arc_angle_start+arc_angle,
+                 aCornerRadius, true );
+        }
+        else
+            LineTo( rr_edge.m_end );
+    }
+
+    fputs( "G37*\n", outputFile );      // Close region
+}
+
 
 void GERBER_PLOTTER::FlashPadCustom( const wxPoint& aPadPos, const wxSize& aSize,
                                      SHAPE_POLY_SET* aPolygons,

include/plotter.h

@@ -1328,6 +1328,30 @@ public:
                     APERTURE::APERTURE_TYPE aType, int aApertureAttribute );
 
 protected:
+    /** Plot a round rect (a round rect shape in fact) as a Gerber region
+     * using lines and arcs for corners
+     * @param aRectCenter is the center of the rectangle
+     * @param aSize is the size of the rectangle
+     * @param aCornerRadius is the radius of the corners
+     * @param aOrient is the rotation of the rectangle
+     * Note: only the G36 ... G37 region is created.
+     */
+    void plotRoundRectAsRegion( const wxPoint& aRectCenter, const wxSize& aSize,
+                                int aCornerRadius, double aOrient );
+    /**
+     * Plot a Gerber arc.
+     * if aPlotInRegion = true, the current pen position will not be
+     * initialized to the arc start position, and therefore the arc can be used
+     * to define a region outline item
+     * a line will be created from current ^position to arc start point
+     * if aPlotInRegion = false, the current pen position will be initialized
+     * to the arc start position, to plot an usual arc item
+     * The line thickness is not initialized in plotArc, and must be initialized
+     * before calling it if needed.
+     */
+    void plotArc( const wxPoint& aCenter, double aStAngle, double aEndAngle,
+                      int aRadius, bool aPlotInRegion );
+
     /**
      * Pick an existing aperture or create a new one, matching the
      * size, type and attributes.

pcbnew/plot_brditems_plotter.cpp

@@ -792,6 +792,12 @@ void BRDITEMS_PLOTTER::PlotDrawSegment( DRAWSEGMENT* aSeg )
     if( aSeg->GetLayer() == Edge_Cuts )
         gbr_metadata.SetApertureAttrib( GBR_APERTURE_METADATA::GBR_APERTURE_ATTRIB_EDGECUT );
 
+    if( IsCopperLayer( aSeg->GetLayer() ) )
+        // Graphic items (DRAWSEGMENT, TEXT) having no net have the NonConductor attribute
+        // Graphic items having a net have the Conductor attribute, but are not (yet?)
+        // supported in Pcbnew
+        gbr_metadata.SetApertureAttrib( GBR_APERTURE_METADATA::GBR_APERTURE_ATTRIB_NONCONDUCTOR );
+
     switch( aSeg->GetShape() )
     {
     case S_CIRCLE: