/*
* This program source code file is part of KiCad, a free EDA CAD application.
*
* Copyright (C) 2017 Jean-Pierre Charras, jp.charras at wanadoo.fr
* Copyright (C) 1992-2017 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
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you may find one here:
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
* or you may search the http://www.gnu.org website for the version 2 license,
* or you may write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
/**
* @file class_zone.h
* @brief Classes to handle copper zones
*/
#ifndef CLASS_ZONE_H_
#define CLASS_ZONE_H_
#include <vector>
#include <gr_basic.h>
#include <class_board_item.h>
#include <board_connected_item.h>
#include <layers_id_colors_and_visibility.h>
#include <PolyLine.h>
#include <geometry/shape_poly_set.h>
#include <zone_settings.h>
class EDA_RECT;
class LINE_READER;
class EDA_DRAW_PANEL;
class PCB_EDIT_FRAME;
class BOARD;
class ZONE_CONTAINER;
class MSG_PANEL_ITEM;
typedef std::vector<SEG> ZONE_SEGMENT_FILL;
/**
* Class ZONE_CONTAINER
* handles a list of polygons defining a copper zone.
* A zone is described by a main polygon, a time stamp, a layer, and a net name.
* Other polygons inside the main polygon are holes in the zone.
*/
class ZONE_CONTAINER : public BOARD_CONNECTED_ITEM
{
public:
/**
* Zone hatch styles
*/
typedef enum HATCH_STYLE { NO_HATCH, DIAGONAL_FULL, DIAGONAL_EDGE } HATCH_STYLE;
ZONE_CONTAINER( BOARD* parent );
ZONE_CONTAINER( const ZONE_CONTAINER& aZone );
ZONE_CONTAINER& operator=( const ZONE_CONTAINER &aOther );
~ZONE_CONTAINER();
/**
* Function GetPosition
*
* Returns a reference to the first corner of the polygon set.
*
* \warning The implementation of this function relies on the fact that wxPoint and VECTOR2I
* have the same layout. If you intend to use the returned reference directly, please note
* that you are _only_ allowed to use members x and y. Any use on anything that is not one of
* these members will have undefined behaviour.
*
* @return a wxPoint, position of the first point of the outline
*/
const wxPoint GetPosition() const override;
void SetPosition( const wxPoint& aPos ) override {}
/**
* Function SetPriority
* @param aPriority = the priority level
*/
void SetPriority( unsigned aPriority ) { m_priority = aPriority; }
/**
* Function GetPriority
* @return the priority level of this zone
*/
unsigned GetPriority() const { return m_priority; }
void GetMsgPanelInfo( std::vector< MSG_PANEL_ITEM >& aList ) override;
void SetLayerSet( LSET aLayerSet );
virtual LSET GetLayerSet() const override;
/**
* Function Draw
* Draws the zone outline.
* @param panel = current Draw Panel
* @param DC = current Device Context
* @param aDrawMode = GR_OR, GR_XOR, GR_COPY ..
* @param offset = Draw offset (usually wxPoint(0,0))
*/
void Draw( EDA_DRAW_PANEL* panel,
wxDC* DC,
GR_DRAWMODE aDrawMode,
const wxPoint& offset = ZeroOffset ) override;
/**
* Function DrawDrawFilledArea
* Draws the filled area for this zone (polygon list .m_FilledPolysList)
* @param panel = current Draw Panel
* @param DC = current Device Context
* @param offset = Draw offset (usually wxPoint(0,0))
* @param aDrawMode = GR_OR, GR_XOR, GR_COPY ..
*/
void DrawFilledArea( EDA_DRAW_PANEL* panel,
wxDC* DC,
GR_DRAWMODE aDrawMode,
const wxPoint& offset = ZeroOffset );
/**
* Function DrawWhileCreateOutline
* Draws the zone outline when it is created.
* The moving edges are in XOR graphic mode, old segment in draw_mode graphic mode
* (usually GR_OR). The closing edge has its own shape.
* @param panel = current Draw Panel
* @param DC = current Device Context
* @param draw_mode = draw mode: OR, XOR ..
*/
void DrawWhileCreateOutline( EDA_DRAW_PANEL* panel, wxDC* DC,
GR_DRAWMODE draw_mode = GR_OR );
/** Function GetBoundingBox (virtual)
* @return an EDA_RECT that is the bounding box of the zone outline
*/
const EDA_RECT GetBoundingBox() const override;
int GetClearance( BOARD_CONNECTED_ITEM* aItem = NULL ) const override;
/**
* Function IsOnCopperLayer
* @return true if this zone is on a copper layer, false if on a technical layer
*/
bool IsOnCopperLayer() const;
/**
* Function CommonLayerExist
* Test if this zone shares a common layer with the given layer set
*/
bool CommonLayerExists( const LSET aLayerSet ) const;
virtual void SetLayer( PCB_LAYER_ID aLayer ) override;
virtual PCB_LAYER_ID GetLayer() const override;
virtual bool IsOnLayer( PCB_LAYER_ID ) const override;
virtual void ViewGetLayers( int aLayers[], int& aCount ) const override;
void SetFillMode( ZONE_FILL_MODE aFillMode ) { m_FillMode = aFillMode; }
ZONE_FILL_MODE GetFillMode() const { return m_FillMode; }
void SetThermalReliefGap( int aThermalReliefGap ) { m_ThermalReliefGap = aThermalReliefGap; }
int GetThermalReliefGap( D_PAD* aPad = NULL ) const;
void SetThermalReliefCopperBridge( int aThermalReliefCopperBridge )
{
m_ThermalReliefCopperBridge = aThermalReliefCopperBridge;
}
int GetThermalReliefCopperBridge( D_PAD* aPad = NULL ) const;
void SetArcSegmentCount( int aArcSegCount ) { m_ArcToSegmentsCount = aArcSegCount; }
int GetArcSegmentCount() const { return m_ArcToSegmentsCount; }
bool IsFilled() const { return m_IsFilled; }
void SetIsFilled( bool isFilled ) { m_IsFilled = isFilled; }
int GetZoneClearance() const { return m_ZoneClearance; }
void SetZoneClearance( int aZoneClearance ) { m_ZoneClearance = aZoneClearance; }
ZoneConnection GetPadConnection( D_PAD* aPad = NULL ) const;
void SetPadConnection( ZoneConnection aPadConnection ) { m_PadConnection = aPadConnection; }
int GetMinThickness() const { return m_ZoneMinThickness; }
void SetMinThickness( int aMinThickness ) { m_ZoneMinThickness = aMinThickness; }
int GetSelectedCorner() const
{
// Transform relative indices to global index
int globalIndex;
m_Poly->GetGlobalIndex( *m_CornerSelection, globalIndex );
return globalIndex;
}
void SetSelectedCorner( int aCorner )
{
SHAPE_POLY_SET::VERTEX_INDEX selectedCorner;
// If the global index of the corner is correct, assign it to m_CornerSelection
if( m_Poly->GetRelativeIndices( aCorner, &selectedCorner ) )
{
if( m_CornerSelection == nullptr )
m_CornerSelection = new SHAPE_POLY_SET::VERTEX_INDEX;
*m_CornerSelection = selectedCorner;
}
else
throw( std::out_of_range( "aCorner-th vertex does not exist" ) );
}
///
// Like HitTest but selects the current corner to be operated on
void SetSelectedCorner( const wxPoint& aPosition );
int GetLocalFlags() const { return m_localFlgs; }
void SetLocalFlags( int aFlags ) { m_localFlgs = aFlags; }
ZONE_SEGMENT_FILL& FillSegments() { return m_FillSegmList; }
const ZONE_SEGMENT_FILL& FillSegments() const { return m_FillSegmList; }
SHAPE_POLY_SET* Outline() { return m_Poly; }
const SHAPE_POLY_SET* Outline() const { return const_cast< SHAPE_POLY_SET* >( m_Poly ); }
void SetOutline( SHAPE_POLY_SET* aOutline ) { m_Poly = aOutline; }
/**
* Function HitTest
* tests if a point is near an outline edge or a corner of this zone.
* @param aPosition the wxPoint to test
* @return bool - true if a hit, else false
*/
virtual bool HitTest( const wxPoint& aPosition ) const override;
/**
* Function HitTest
* tests if a point is inside the zone area, i.e. inside the main outline
* and outside holes.
* @param aPosition : the wxPoint to test
* @return bool - true if a hit, else false
*/
bool HitTestInsideZone( const wxPoint& aPosition ) const
{
return m_Poly->Contains( VECTOR2I( aPosition ), 0 );
}
/**
* Function HitTestFilledArea
* tests if the given wxPoint is within the bounds of a filled area of this zone.
* @param aRefPos A wxPoint to test
* @return bool - true if a hit, else false
*/
bool HitTestFilledArea( const wxPoint& aRefPos ) const;
/**
* Function TransformSolidAreasShapesToPolygonSet
* Convert solid areas full shapes to polygon set
* (the full shape is the polygon area with a thick outline)
* Used in 3D view
* Arcs (ends of segments) are approximated by segments
* @param aCornerBuffer = a buffer to store the polygons
* @param aCircleToSegmentsCount = the number of segments to approximate a circle
* @param aCorrectionFactor = the correction to apply to arcs radius to roughly
* keep arc radius when approximated by segments
*/
void TransformSolidAreasShapesToPolygonSet( SHAPE_POLY_SET& aCornerBuffer,
int aCircleToSegmentsCount,
double aCorrectionFactor ) const;
/**
* Function TransformOutlinesShapeWithClearanceToPolygon
* Convert the outlines shape to a polygon with no holes
* inflated (optional) by max( aClearanceValue, the zone clearance)
* (holes are linked to external outline by overlapping segments)
* Used in filling zones calculations
* Circles (vias) and arcs (ends of tracks) are approximated by segments
* @param aCornerBuffer = a buffer to store the polygon
* @param aMinClearanceValue = the min clearance around outlines
* @param aUseNetClearance = true to use a clearance which is the max value between
* aMinClearanceValue and the net clearance
* false to use aMinClearanceValue only
* if both aMinClearanceValue = 0 and aUseNetClearance = false: create the zone outline polygon.
*/
void TransformOutlinesShapeWithClearanceToPolygon( SHAPE_POLY_SET& aCornerBuffer,
int aMinClearanceValue,
bool aUseNetClearance ) const;
void TransformShapeWithClearanceToPolygon( SHAPE_POLY_SET& aCornerBuffer,
int aClearanceValue,
int aCircleToSegmentsCount,
double aCorrectionFactor ) const override;
/**
* Function HitTestForCorner
* tests if the given wxPoint is near a corner.
* @param refPos is the wxPoint to test.
* @param aCornerHit [out] is the index of the closest vertex found, useless when return
* value is false.
* @return bool - true if some corner was found to be closer to refPos than aClearance; false
* otherwise.
*/
bool HitTestForCorner( const wxPoint& refPos, SHAPE_POLY_SET::VERTEX_INDEX& aCornerHit ) const;
/**
* Function HitTestForCorner
* tests if the given wxPoint is near a corner.
* @param refPos is the wxPoint to test.
* @return bool - true if some corner was found to be closer to refPos than aClearance; false
* otherwise.
*/
bool HitTestForCorner( const wxPoint& refPos ) const;
/**
* Function HitTestForEdge
* tests if the given wxPoint is near a segment defined by 2 corners.
* @param refPos is the wxPoint to test.
* @param aCornerHit [out] is the index of the closest vertex found, useless when return
* value is false.
* @return bool - true if some edge was found to be closer to refPos than aClearance.
*/
bool HitTestForEdge( const wxPoint& refPos, SHAPE_POLY_SET::VERTEX_INDEX& aCornerHit ) const;
/**
* Function HitTestForEdge
* tests if the given wxPoint is near a segment defined by 2 corners.
* @param refPos is the wxPoint to test.
* @return bool - true if some edge was found to be closer to refPos than aClearance.
*/
bool HitTestForEdge( const wxPoint& refPos ) const;
/** @copydoc BOARD_ITEM::HitTest(const EDA_RECT& aRect,
* bool aContained = true, int aAccuracy ) const
*/
bool HitTest( const EDA_RECT& aRect, bool aContained = true, int aAccuracy = 0 ) const override;
/**
* Function UnFill
* Removes the zone filling
* @return true if a previous filling is removed, false if no change
* (when no filling found)
*/
bool UnFill();
/* Geometric transformations: */
/**
* Function Move
* Move the outlines
* @param offset = moving vector
*/
void Move( const wxPoint& offset ) override;
/**
* Function MoveEdge
* Move the outline Edge
* @param offset = moving vector
* @param aEdge = start point of the outline edge
*/
void MoveEdge( const wxPoint& offset, int aEdge );
/**
* Function Rotate
* Move the outlines
* @param centre = rot centre
* @param angle = in 0.1 degree
*/
void Rotate( const wxPoint& centre, double angle ) override;
/**
* Function Flip
* Flip this object, i.e. change the board side for this object
* (like Mirror() but changes layer)
* @param aCentre - the rotation point.
*/
virtual void Flip( const wxPoint& aCentre ) override;
/**
* Function Mirror
* Mirror the outlines , relative to a given horizontal axis
* the layer is not changed
* @param mirror_ref = vertical axis position
*/
void Mirror( const wxPoint& mirror_ref );
/**
* Function GetClass
* returns the class name.
* @return wxString
*/
wxString GetClass() const override
{
return wxT( "ZONE_CONTAINER" );
}
/** Access to m_Poly parameters
*/
int GetNumCorners( void ) const
{
return m_Poly->TotalVertices();
}
/**
* Function Iterate
* returns an iterator to visit all points of the zone's main outline without holes.
* @return SHAPE_POLY_SET::ITERATOR - an iterator to visit the zone vertices without holes.
*/
SHAPE_POLY_SET::ITERATOR Iterate()
{
return m_Poly->Iterate();
}
/**
* Function IterateWithHoles
* returns an iterator to visit all points of the zone's main outline with holes.
* @return SHAPE_POLY_SET::ITERATOR - an iterator to visit the zone vertices with holes.
*/
SHAPE_POLY_SET::ITERATOR IterateWithHoles()
{
return m_Poly->IterateWithHoles();
}
/**
* Function CIterateWithHoles
* returns an iterator to visit all points of the zone's main outline with holes.
* @return SHAPE_POLY_SET::ITERATOR - an iterator to visit the zone vertices with holes.
*/
SHAPE_POLY_SET::CONST_ITERATOR CIterateWithHoles() const
{
return m_Poly->CIterateWithHoles();
}
void RemoveAllContours( void )
{
m_Poly->RemoveAllContours();
}
const VECTOR2I& GetCornerPosition( int aCornerIndex ) const
{
SHAPE_POLY_SET::VERTEX_INDEX index;
// Convert global to relative indices
if( !m_Poly->GetRelativeIndices( aCornerIndex, &index ) )
throw( std::out_of_range( "aCornerIndex-th vertex does not exist" ) );
return m_Poly->CVertex( index );
}
void SetCornerPosition( int aCornerIndex, wxPoint new_pos )
{
SHAPE_POLY_SET::VERTEX_INDEX relativeIndices;
// Convert global to relative indices
if( m_Poly->GetRelativeIndices( aCornerIndex, &relativeIndices ) )
{
m_Poly->Vertex( relativeIndices ).x = new_pos.x;
m_Poly->Vertex( relativeIndices ).y = new_pos.y;
}
else
throw( std::out_of_range( "aCornerIndex-th vertex does not exist" ) );
}
/**
* Function NewHole
* creates a new hole on the zone; i.e., a new contour on the zone's outline.
*/
void NewHole()
{
m_Poly->NewHole();
}
/**
* Add a new corner to the zone outline (to the main outline or a hole)
* @param aPosition is the position of the new corner.
* @param aHoleIdx is the index of the hole (-1 for the main outline, >= 0 for hole).
* @param aAllowDuplication is a flag to indicate whether it is allowed to add this corner
* even if it is duplicated.
* @return true if the corner was added, false if error (aHoleIdx > hole count -1)
*/
bool AppendCorner( wxPoint aPosition, int aHoleIdx, bool aAllowDuplication = false );
HATCH_STYLE GetHatchStyle() const
{
return m_hatchStyle;
}
void SetHatchStyle( HATCH_STYLE aStyle )
{
m_hatchStyle = aStyle;
}
/**
* Function IsSame
* tests if 2 zones are equivalent:
* 2 zones are equivalent if they have same parameters and same outlines
* info, filling is not taken into account
* @param aZoneToCompare = zone to compare with "this"
*/
bool IsSame( const ZONE_CONTAINER &aZoneToCompare );
/**
* Function ClearFilledPolysList
* clears the list of filled polygons.
*/
void ClearFilledPolysList()
{
m_FilledPolysList.RemoveAllContours();
}
/**
* Function GetFilledPolysList
* returns a reference to the list of filled polygons.
* @return Reference to the list of filled polygons.
*/
//TODO - This should be called for each layer on which the zone exists
const SHAPE_POLY_SET& GetFilledPolysList() const
{
return m_FilledPolysList;
}
void CacheTriangulation();
/**
* Function SetFilledPolysList
* sets the list of filled polygons.
*/
void SetFilledPolysList( SHAPE_POLY_SET& aPolysList )
{
m_FilledPolysList = aPolysList;
}
/**
* Function SetFilledPolysList
* sets the list of filled polygons.
*/
void SetRawPolysList( SHAPE_POLY_SET& aPolysList )
{
m_RawPolysList = aPolysList;
}
/**
* Function GetSmoothedPoly
* returns a pointer to the corner-smoothed version of
* m_Poly if it exists, otherwise it returns m_Poly.
* @return SHAPE_POLY_SET* - pointer to the polygon.
*/
bool BuildSmoothedPoly( SHAPE_POLY_SET& aSmoothedPoly ) const;
void SetCornerSmoothingType( int aType ) { m_cornerSmoothingType = aType; };
int GetCornerSmoothingType() const { return m_cornerSmoothingType; };
void SetCornerRadius( unsigned int aRadius );
unsigned int GetCornerRadius() const { return m_cornerRadius; };
/**
* add a polygon to the zone outline
* if the zone outline is empty, this is the main outline
* else it is a hole inside the main outline
*/
void AddPolygon( std::vector< wxPoint >& aPolygon );
void SetFillSegments( const ZONE_SEGMENT_FILL& aSegments )
{
m_FillSegmList = aSegments;
}
SHAPE_POLY_SET& RawPolysList()
{
return m_RawPolysList;
}
wxString GetSelectMenuText() const override;
BITMAP_DEF GetMenuImage() const override;
EDA_ITEM* Clone() const override;
/**
* Accessors to parameters used in Keepout zones:
*/
bool GetIsKeepout() const { return m_isKeepout; }
bool GetDoNotAllowCopperPour() const { return m_doNotAllowCopperPour; }
bool GetDoNotAllowVias() const { return m_doNotAllowVias; }
bool GetDoNotAllowTracks() const { return m_doNotAllowTracks; }
void SetIsKeepout( bool aEnable ) { m_isKeepout = aEnable; }
void SetDoNotAllowCopperPour( bool aEnable ) { m_doNotAllowCopperPour = aEnable; }
void SetDoNotAllowVias( bool aEnable ) { m_doNotAllowVias = aEnable; }
void SetDoNotAllowTracks( bool aEnable ) { m_doNotAllowTracks = aEnable; }
/**
* Hatch related methods
*/
/**
* Function GetHatchPitch
* @return int - the zone hatch pitch in iu.
*/
int GetHatchPitch() const;
/**
* Function GetDefaultHatchPitchMils
* @return int - the default hatch pitch in internal units.
*/
static int GetDefaultHatchPitch();
/**
* Function SetHatch
* sets all hatch parameters for the zone.
* @param aHatchStyle is the style of the hatch, specified as one of HATCH_STYLE possible
* values.
* @param aHatchPitch is the hatch pitch in iu.
* @param aRebuildHatch is a flag to indicate whether to re-hatch after having set the
* previous parameters.
*/
void SetHatch( int aHatchStyle, int aHatchPitch, bool aRebuildHatch );
/**
* Function SetHatchPitch
* sets the hatch pitch parameter for the zone.
* @param aPitch is the hatch pitch in iu.
*/
void SetHatchPitch( int aPitch );
/**
* Function UnHatch
* clears the zone's hatch.
*/
void UnHatch();
/**
* Function Hatch
* computes the hatch lines depending on the hatch parameters and stores it in the zone's
* attribute m_HatchLines.
*/
void Hatch();
const std::vector<SEG>& GetHatchLines() const { return m_HatchLines; }
bool GetHV45() const { return m_hv45; }
void SetHV45( bool aConstrain ) { m_hv45 = aConstrain; }
#if defined(DEBUG)
virtual void Show( int nestLevel, std::ostream& os ) const override { ShowDummy( os ); }
#endif
virtual void SwapData( BOARD_ITEM* aImage ) override;
private:
SHAPE_POLY_SET* m_Poly; ///< Outline of the zone.
int m_cornerSmoothingType;
unsigned int m_cornerRadius;
LSET m_layerSet;
/* Priority: when a zone outline is inside and other zone, if its priority is higher
* the other zone priority, it will be created inside.
* if priorities are equal, a DRC error is set
*/
unsigned m_priority;
/* A zone outline can be a keepout zone.
* It will be never filled, and DRC should test for pads, tracks and vias
*/
bool m_isKeepout;
/* For keepout zones only:
* what is not allowed inside the keepout ( pads, tracks and vias )
*/
bool m_doNotAllowCopperPour;
bool m_doNotAllowVias;
bool m_doNotAllowTracks;
ZoneConnection m_PadConnection;
int m_ZoneClearance; ///< Clearance value in internal units.
int m_ZoneMinThickness; ///< Minimum thickness value in filled areas.
/** The number of segments to convert a circle to a polygon. Valid values are
#ARC_APPROX_SEGMENTS_COUNT_LOW_DEF or #ARC_APPROX_SEGMENTS_COUNT_HIGHT_DEF. */
int m_ArcToSegmentsCount;
/** True when a zone was filled, false after deleting the filled areas. */
bool m_IsFilled;
///< Width of the gap in thermal reliefs.
int m_ThermalReliefGap;
///< Width of the copper bridge in thermal reliefs.
int m_ThermalReliefCopperBridge;
/// How to fill areas: ZFM_POLYGONS => use filled polygons, ZFM_SEGMENTS => fill with segments.
ZONE_FILL_MODE m_FillMode;
/// The index of the corner being moved or nullptr if no corner is selected.
SHAPE_POLY_SET::VERTEX_INDEX* m_CornerSelection;
/// Variable used in polygon calculations.
int m_localFlgs;
/** Segments used to fill the zone (#m_FillMode ==1 ), when fill zone by segment is used.
* In this case the segments have #m_ZoneMinThickness width.
*/
ZONE_SEGMENT_FILL m_FillSegmList;
/* set of filled polygons used to draw a zone as a filled area.
* from outlines (m_Poly) but unlike m_Poly these filled polygons have no hole
* (they are all in one piece) In very simple cases m_FilledPolysList is same
* as m_Poly. In less simple cases (when m_Poly has holes) m_FilledPolysList is
* a polygon equivalent to m_Poly, without holes but with extra outline segment
* connecting "holes" with external main outline. In complex cases an outline
* described by m_Poly can have many filled areas
*/
SHAPE_POLY_SET m_FilledPolysList;
SHAPE_POLY_SET m_RawPolysList;
HATCH_STYLE m_hatchStyle; // hatch style, see enum above
int m_hatchPitch; // for DIAGONAL_EDGE, distance between 2 hatch lines
std::vector<SEG> m_HatchLines; // hatch lines
std::vector<int> m_insulatedIslands;
bool m_hv45; // constrain edges to horizontal, vertical or 45ยบ
/**
* Union to handle conversion between references to wxPoint and to VECTOR2I.
*
* The function GetPosition(), that returns a reference to a wxPoint, needs some existing
* wxPoint object that it can point to. The header of this function cannot be changed, as it
* overrides the function from the base class BOARD_ITEM. This made sense when ZONE_CONTAINER
* was implemented using the legacy CPolyLine class, that worked with wxPoints. However,
* m_Poly is now a SHAPE_POLY_SET, whose corners are objects of type VECTOR2I, not wxPoint.
* Thus, we cannot directly reference the first corner of m_Poly, so a modified version of it
* that can be read as a wxPoint needs to be handled.
* Taking advantage of the fact that both wxPoint and VECTOR2I have the same memory layout
* (two integers: x, y), this union let us convert a reference to a VECTOR2I into a reference
* to a wxPoint.
*
* The idea is the following: in GetPosition(), m_Poly->GetCornerPosition( 0 ) returns a
* reference to the first corner of the polygon set. If we retrieve its memory direction, we
* can tell the compiler to cast that pointer to a WX_VECTOR_CONVERTER pointer. We can finally
* shape that memory layout as a wxPoint picking the wx member of the union.
*
* Although this solution is somewhat unstable, as it relies on the fact that the memory
* layout is exactly the same, it is the best attempt to keep backwards compatibility while
* using the new SHAPE_POLY_SET.
*/
typedef union {
wxPoint wx;
VECTOR2I vector;
} WX_VECTOR_CONVERTER;
// Sanity check: assure that the conversion VECTOR2I->wxPoint using the previous union is
// correct, making sure that the access for x and y attributes is still safe.
static_assert(offsetof(wxPoint,x) == offsetof(VECTOR2I,x),
"wxPoint::x and VECTOR2I::x have different offsets");
static_assert(offsetof(wxPoint,y) == offsetof(VECTOR2I,y),
"wxPoint::y and VECTOR2I::y have different offsets");
};
#endif // CLASS_ZONE_H_