/* * This program source code file is part of KiCad, a free EDA CAD application. * * Copyright (C) 2015 Jean-Pierre Charras, jp.charras at wanadoo.fr * Copyright (C) 1992-2015 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 #include #include #include #include #include #include #include class EDA_RECT; class LINE_READER; class EDA_DRAW_PANEL; class PCB_EDIT_FRAME; class BOARD; class ZONE_CONTAINER; class MSG_PANEL_ITEM; /** * Struct SEGMENT * is a simple container used when filling areas with segments */ struct SEGMENT { wxPoint m_Start; // starting point of a segment wxPoint m_End; // ending point of a segment SEGMENT() {} SEGMENT( const wxPoint& aStart, const wxPoint& aEnd ) { m_Start = aStart; m_End = aEnd; } }; /** * 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; /** * 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 TestForCopperIslandAndRemoveInsulatedIslands * Remove insulated copper islands found in m_FilledPolysList. * @param aPcb = the board to analyze */ void TestForCopperIslandAndRemoveInsulatedIslands( BOARD* aPcb ); /** * Function IsOnCopperLayer * @return true if this zone is on a copper layer, false if on a technical layer */ bool IsOnCopperLayer() const { return IsCopperLayer( GetLayer() ); } /// How to fill areas: 0 = use filled polygons, 1 => fill with segments. void SetFillMode( int aFillMode ) { m_FillMode = aFillMode; } int 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; } std::vector & FillSegments() { return m_FillSegmList; } const std::vector & 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 BuildFilledSolidAreasPolygons * Build the filled solid areas data from real outlines (stored in m_Poly) * The solid areas can be more than one on copper layers, and do not have holes ( holes are linked by overlapping segments to the main outline) * in order to have drawable (and plottable) filled polygons * @return true if OK, false if the solid polygons cannot be built * @param aPcb: the current board (can be NULL for non copper zones) * @param aCornerBuffer: A reference to a buffer to store polygon corners, or NULL * if NULL (default: * - m_FilledPolysList is used to store solid areas polygons. * - on copper layers, tracks and other items shapes of other nets are * removed from solid areas * if not null: * Only the zone outline (with holes, if any) is stored in aOutlineBuffer * with holes linked. Therefore only one polygon is created * * When aOutlineBuffer is not null, his function calls * AddClearanceAreasPolygonsToPolysList() to add holes for pads and tracks * and other items not in net. */ bool BuildFilledSolidAreasPolygons( BOARD* aPcb, SHAPE_POLY_SET* aOutlineBuffer = NULL ); /** * Function AddClearanceAreasPolygonsToPolysList * Add non copper areas polygons (pads and tracks with clearance) * to a filled copper area * used in BuildFilledSolidAreasPolygons when calculating filled areas in a zone * Non copper areas are pads and track and their clearance area * The filled copper area must be computed before * BuildFilledSolidAreasPolygons() call this function just after creating the * filled copper area polygon (without clearance areas * @param aPcb: the current board * _NG version uses SHAPE_POLY_SET instead of Boost.Polygon */ void AddClearanceAreasPolygonsToPolysList( BOARD* aPcb ); void AddClearanceAreasPolygonsToPolysList_NG( BOARD* aPcb ); /** * 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 ); /** * 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 FillZoneAreasWithSegments * Fill sub areas in a zone with segments with m_ZoneMinThickness width * A scan is made line per line, on the whole filled areas, with a step of m_ZoneMinThickness. * all intersecting points with the horizontal infinite line and polygons to fill are calculated * a list of SEGZONE items is built, line per line * @return true if success, false on error */ bool FillZoneAreasWithSegments(); /** * 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(); } /** * Function AppendCorner * @param position is the position of the new corner. * @param aAllowDuplication is a flag to indicate whether it is allowed to add this corner * even if it is duplicated. */ void AppendCorner( wxPoint position, bool aAllowDuplication = false ) { if( m_Poly->OutlineCount() == 0 ) m_Poly->NewOutline(); m_Poly->Append( position.x, position.y, -1, -1, aAllowDuplication ); } 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. */ const SHAPE_POLY_SET& GetFilledPolysList() const { return m_FilledPolysList; } /** * Function AddFilledPolysList * sets the list of filled polygons. */ void AddFilledPolysList( SHAPE_POLY_SET& aPolysList ) { m_FilledPolysList = 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. */ SHAPE_POLY_SET* GetSmoothedPoly() const { if( m_smoothedPoly ) return m_smoothedPoly; else return m_Poly; }; 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; }; void AddPolygon( std::vector< wxPoint >& aPolygon ); void AddFilledPolygon( SHAPE_POLY_SET& aPolygon ) { m_FilledPolysList.Append( aPolygon ); } void AddFillSegments( std::vector< SEGMENT >& aSegments ) { m_FillSegmList.insert( m_FillSegmList.end(), aSegments.begin(), aSegments.end() ); } 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 mils. * * \todo This value is hardcoded, but it should be user configurable. */ static int GetDefaultHatchPitchMils() { return 20; } /** * 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& GetHatchLines() const { return m_HatchLines; } #if defined(DEBUG) virtual void Show( int nestLevel, std::ostream& os ) const override { ShowDummy( os ); } #endif private: void buildFeatureHoleList( BOARD* aPcb, SHAPE_POLY_SET& aFeatures ); SHAPE_POLY_SET* m_Poly; ///< Outline of the zone. SHAPE_POLY_SET* m_smoothedPoly; // Corner-smoothed version of m_Poly int m_cornerSmoothingType; unsigned int m_cornerRadius; /* 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: 0 => use filled polygons, 1 => fill with segments. int 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. */ std::vector 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; HATCH_STYLE m_hatchStyle; // hatch style, see enum above int m_hatchPitch; // for DIAGONAL_EDGE, distance between 2 hatch lines std::vector m_HatchLines; // hatch lines /** * 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_